Some implementations of the disclosure are directed to an additive manufacturing build plate structure for metal build surface stabilization during 3D printing and facile release of 3D printed objects. The build plate includes a body having a recessed section formed through a first surface of the body, the recessed section including a bottom surface within the body and sidewalls extending to the bottom surface. The recessed section is configured to be filled with a solid form of a metal or metal alloy that provides a printing surface for forming a 3D object in a 3D printing device. The recessed section includes a locking mechanism configured to prevent lift-up of the solid form of the metal or metal alloy during 3D printing in the 3D printing device.
A method includes: obtaining a build plate useable in a 3D printing device, the build plate including a recessed section extending through a top surface of the build plate, and the recessed section including first and second sidewalls, and a lower surface extending from the first sidewall to the second sidewall; filling the recessed section with a liquid form of a metal or metal alloy; and cooling the metal or metal alloy below its solidus temperature such that the liquid form of the metal or metal alloy solidifies into a solid form of the metal or metal alloy. The solid form contacts the first sidewall, the second sidewall, and the lower surface. The solid form includes a build surface for forming a 3D printed metal object in the 3D printing device. The 3D printed metal object is releasable by melting the solid form of the metal or metal alloy.
Some implementations of the disclosure are directed to an additive manufacturing build plate structure for metal build surface stabilization during 3D printing and facile release of 3D printed objects. The build plate includes a body having a recessed section formed through a first surface of the body, the recessed section including a bottom surface within the body and sidewalls extending to the bottom surface. The recessed section is configured to be filled with a solid form of a metal or metal alloy that provides a printing surface for forming a 3D object in a 3D printing device. The recessed section includes a locking mechanism configured to prevent lift-up of the solid form of the metal or metal alloy during 3D printing in the 3D printing device.
Some implementations of the disclosure are directed to an additive manufacturing build plate structure for metal build surface stabilization during 3D printing and facile release of 3D printed objects. The build plate includes a body having a recessed section formed through a first surface of the body, the recessed section including a bottom surface within the body and sidewalls extending to the bottom surface. The recessed section is configured to be filled with a solid form of a metal or metal alloy that provides a printing surface for forming a 3D object in a 3D printing device. The recessed section includes a locking mechanism configured to prevent lift-up of the solid form of the metal or metal alloy during 3D printing in the 3D printing device.
Some implementations of the disclosure are directed to liquid metal pastes that can be used as thermal interface materials. In one implementation, a liquid metal paste configured to be applied as a thermal interface material between electronic components, includes: 92.5wt% of 99.9 wt% of a liquid gallium or liquid gallium alloy; and 0.1wt% to 7.5wt% of a powder of metal particles, the metal particles including Ag, Au, Cu, W, Ti, Cr, Ni, Cu or Ni. The liquid metal paste can also include an organic compound coating a surface of the metal particles, the organic compound configured to prevent the metal particles from forming an intermetallic compound with the liquid gallium or liquid gallium alloy.
B23K 35/02 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
B23K 35/26 - Selection of soldering or welding materials proper with the principal constituent melting at less than 400°C
C22C 28/00 - Alloys based on a metal not provided for in groups
B22F 1/102 - Metallic powder coated with organic material
H01L 23/00 - Details of semiconductor or other solid state devices
B23K 35/36 - Selection of non-metallic compositions, e.g. coatings, fluxesSelection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
6.
LIQUID METAL PASTE CONTAINING METAL PARTICLE ADDITIVE
Some implementations of the disclosure are directed to liquid metal pastes that can be used as thermal interface materials. In one implementation, a liquid metal paste configured to be applied as a thermal interface material between electronic components, includes: 92.5 wt % of 99.9 wt % of a liquid gallium or liquid gallium alloy; and 0.1 wt % to 7.5 wt % of a powder of metal particles, the metal particles including Ag, Au, Cu, W, Ti, Cr, Ni, Cu or Ni. The liquid metal paste can also include an organic compound coating a surface of the metal particles, the organic compound configured to prevent the metal particles from forming an intermetallic compound with the liquid gallium or liquid gallium alloy.
A solder preform in the shape of a solder tube or washer includes: a cylindrically shaped solder alloy body including an inner surface, an outer surface, a first end, a second end, a first opening located at the first end, and a second opening located at the second end, the second end interlocking with the first end, and the first opening and the second opening cut along an entire height of the solder alloy body; and a flux core embedded in the solder alloy body between the inner surface and the outer surface, the flux core including a thermochromic indicator. During reflow soldering, the flux core including the thermochromic indicator flows out of the first opening of the first end and the second opening of the second end to coat the inner surface of the solder alloy body and the outer surface of the solder alloy body.
B23K 35/02 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
B23K 35/26 - Selection of soldering or welding materials proper with the principal constituent melting at less than 400°C
B23K 35/22 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
8.
LIQUID METAL COMPOSITES CONTAINING ORGANIC ADDITIVE AS THERMAL INTERFACE MATERIALS, AND METHODS OF THEIR USE
Some implementations of the disclosure are directed to liquid metal composites that can be used as thermal interface materials. In one implementation, a liquid metal composite configured to be applied as a thermal interface material between electronic components, includes: 90 wt % to 99.9 wt % of a liquid metal or liquid metal alloy; and 0.1 wt % to 10 wt % of at least one organic additive comprising an organic compound to prevent oxidation of the liquid metal or liquid metal alloy during application of the liquid metal composite on a surface of an electronic component.
H01L 23/473 - Arrangements for cooling, heating, ventilating or temperature compensation involving the transfer of heat by flowing fluids by flowing liquids
H01L 23/373 - Cooling facilitated by selection of materials for the device
C22C 28/00 - Alloys based on a metal not provided for in groups
9.
LIQUID METAL COMPOSITES CONTAINING ORGANIC ADDITIVE AS THERMAL INTERFACE MATERIALS, AND METHODS OF THEIR USE
Some implementations of the disclosure are directed to liquid metal composites that can be used as thermal interface materials. In one implementation, a liquid metal composite configured to be applied as a thermal interface material between electronic components, includes: 90wt% to 99.9wt% of a liquid metal or liquid metal alloy; and 0.1wt% to 10wt% of at least one organic additive comprising an organic compound to prevent oxidation of the liquid metal or liquid metal alloy during application of the liquid metal composite on a surface of an electronic component.
Some implementations of the disclosure are directed to a method, comprising: receiving a sheet of graphite comprising a first surface and a second surface opposite the first surface; and perforating the sheet in a first plurality of locations from the first surface through the second surface to form a first plurality of perforations through the sheet and a first plurality of protrusions of the graphite oriented outward from the second surface, the first plurality of protrusions configured to conduct heat away from a plane of the sheet. Further implementations comprise perforating the sheet in a second plurality of locations from the second surface through the first surface to form a second plurality of perforations through the sheet and a second plurality of protrusions of graphite material oriented outward from the first surface, wherein the second plurality of protrusions are configured to conduct heat away from the plane of the sheet.
B05D 3/00 - Pretreatment of surfaces to which liquids or other fluent materials are to be appliedAfter-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
B32B 3/26 - Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shapeLayered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layerLayered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shapeLayered products comprising a layer having particular features of form characterised by a layer with cavities or internal voids
B32B 9/00 - Layered products essentially comprising a particular substance not covered by groups
B05D 3/12 - Pretreatment of surfaces to which liquids or other fluent materials are to be appliedAfter-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by mechanical means
H01L 23/373 - Cooling facilitated by selection of materials for the device
C23C 2/02 - Pretreatment of the material to be coated, e.g. for coating on selected surface areas
C23C 2/04 - Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shapeApparatus therefor characterised by the coating material
Some implementations of the disclosure describe a solder paste consisting essentially of: 10 wt% to 90 wt% of a first solder alloy powder, the first solder alloy powder consisting of a Sn-Sb alloy, a Sn-Ag-Cu-Sb alloy, a Sn-Ag-Cu-Sb-ln alloy, a Sn-Ag-Cu-Sb-Bi alloy, or Sn-Ag-Cu-Sb-Bi-ln alloy; 10 wt% to 90 wt% of a second solder alloy powder, the second solder alloy powder consisting of an Sn-Ag-Cu alloy or Sn-Ag-Cu-Bi alloy, and the second solder alloy powder having a lower solidus temperature than the first solder alloy powder; and flux.
C22C 13/02 - Alloys based on tin with antimony or bismuth as the next major constituent
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
12.
HIGH RELIABILITY LEAD-FREE SOLDER PASTES WITH MIXED SOLDER ALLOY POWDERS
Some implementations of the disclosure describe a solder paste consisting essentially of: 10 wt % to 90 wt % of a first solder alloy powder, the first solder alloy powder consisting of a Sn—Sb alloy, a Sn—Ag—Cu—Sb alloy, a Sn—Ag—Cu—Sb—In alloy, a Sn—Ag—Cu—Sb—Bi alloy, or Sn—Ag—Cu—Sb—Bi—In alloy; 10 wt % to 90 wt % of a second solder alloy powder, the second solder alloy powder consisting of an Sn—Ag—Cu alloy or Sn—Ag—Cu—Bi alloy, and the second solder alloy powder having a lower solidus temperature than the first solder alloy powder; and flux.
Solid metal foam thermal interface materials and their uses in electronics assembly are described. In one implementation, a method includes: applying a thermal interface material (TIM) between a first device and a second device to form an assembly having a first surface of the TIM in in touching relation with a surface of the first device, and a second surface of the TIM opposite the first surface in touching relation with a surface of the second device, the TIM comprising a solid metal foam and a first liquid metal; and compressing the assembly to form an alloy from the TIM that bonds the first device to the second device.
H01L 23/373 - Cooling facilitated by selection of materials for the device
H01L 23/367 - Cooling facilitated by shape of device
H01L 21/48 - Manufacture or treatment of parts, e.g. containers, prior to assembly of the devices, using processes not provided for in a single one of the groups or
Liquid metal thermal interface materials and their uses in electronics assembly are described. In one implementation, a semiconductor assembly includes: a semiconductor die; a heat exchanger; and a thermal interface material (TIM) alloy bonding the semiconductor die to the heat exchanger without using a separate metallization layer on a surface of the semiconductor die or a surface of the heat exchanger. The TIM alloy may be formed by placing a TIM material between the semiconductor die and the heat exchanger, the TIM material comprising a first liquid metal foam in touching relation with the surface of the semiconductor die, a second liquid metal foam in touching relation with the surface of the heat exchanger.
Solid metal foam thermal interface materials and their uses in electronics assembly are described. In one implementation, a method includes: applying a thermal interface material (TIM) between a first device and a second device to form an assembly having a first surface of the TIM in in touching relation with a surface of the first device, and a second surface of the TIM opposite the first surface in touching relation with a surface of the second device, the TIM comprising a solid metal foam and a first liquid metal; and compressing the assembly to form an alloy from the TIM that bonds the first device to the second device.
Some implementations of the disclosure are directed to low melting temperature (e.g., liquidus temperature below 210° C.) SnIn solder alloys. A SnIn solder alloy may consist of: 8 to 20 wt % In; greater than 0 wt % to 4 wt % Ag; optionally, one or more of greater than 0 wt % to 5 wt % Sb, greater than 0 wt % to 3 wt % Cu, greater than 0 wt % to 2.5 wt % Zn, greater than 0 wt % to 1.5 wt % Ni, greater than 0 wt % to 1.5 wt % Co, greater than 0 wt % to 1.5 wt % Ge, greater than 0 wt % to 1.5 wt % P, and greater than 0 wt % to 1.5 wt % Mn; and a remainder of Sn.
A SnAgCuSbBi-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics.
Additive manufacturing structures and methods that enable the facile release of 3D printed parts are described. In one implementation, an additive manufacturing structure includes: a body; and a recessed section formed through a surface of the body, the recessed section comprising: a pour hole for filling the recessed section with a liquid metal or metal alloy that solidifies into an insert having a surface for forming a 3D object in a 3D printing device; and one or more air holes configured to release air displaced by the liquid metal or metal alloy.
Thermally decomposable build plates that enable the facile release of 3D printed parts are described. In one implementation, an additive manufacturing build plate comprises: a body including a top surface, a bottom surface, and sidewalls dimensioned such that the build plate is useable in a 3D printing device; and a layer of a solid metal or metal alloy on the top surface of the additive manufacturing build plate, the layer having a solidus temperature that is lower than a solidus temperature of the body, and the layer configured to provide a surface for forming a 3D object in the 3D printing device. In one implementation, an additive manufacturing build plate comprises a recessed section for receiving an insert including a layer of a solid metal or metal alloy on a surface of the insert.
Additive manufacturing structures and methods that enable the facile release of 3D printed parts are described. In one implementation, an additive manufacturing structure includes: a body; and a recessed section formed through a surface of the body, the recessed section comprising: a pour hole for filling the recessed section with a liquid metal or metal alloy that solidifies into an insert having a surface for forming a 3D object in a 3D printing device; and one or more air holes configured to release air displaced by the liquid metal or metal alloy.
Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.
Some implementations of the disclosure relate to a lead-free solder paste with mixed solder powders that is particularly suitable for high temperature soldering applications involving multiple board-level reflow operations. In one implementation, the solder paste consists of 10 wt % to 90 wt % of a first solder alloy powder, the first solder alloy powder consisting of an SnSbCuAg solder alloy that has a wt % ratio of Sn:Sb of 0.75 to 1.1; 10 wt % to 90 wt % of a second solder alloy powder, the second solder alloy powder consisting of an Sn solder alloy including at least 80 wt % of Sn; and a remainder of flux.
Some implementations of the disclosure relate to a lead-free solder paste with mixed solder powders that is particularly suitable for high temperature soldering applications involving multiple board-level reflow operations. In one implementation, the solder paste consists of 10wt% to 90wt% of a first solder alloy powder, the first solder alloy powder consisting of an SnSbCuAg solder alloy that has a wt% ratio of Sn:Sb of 0.75 to 1.1; 10wt% to 90wt% of a second solder alloy powder, the second solder alloy powder consisting of an Sn solder alloy including at least 80wt% of Sn; and a remainder of flux.
Some implementations of the disclosure are directed to a method, comprising: receiving a sheet of graphite comprising a first surface and a second surface opposite the first surface; and perforating the sheet in a first plurality of locations from the first surface through the second surface to form a first plurality of perforations through the sheet and a first plurality of protrusions of the graphite oriented outward from the second surface, the first plurality of protrusions configured to conduct heat away from a plane of the sheet. Further implementations comprise perforating the sheet in a second plurality of locations from the second surface through the first surface to form a second plurality of perforations through the sheet and a second plurality of protrusions of graphite material oriented outward from the first surface, wherein the second plurality of protrusions are configured to conduct heat away from the plane of the sheet.
Implementations of the disclosure are directed to thermally decomposable build plates that enable the facile release of 3D metal printed parts created by additive manufacturing. In some implementations, an additive manufacturing build plate comprises: a top surface, a bottom surface, and sidewalls comprised of a material, wherein the top surface, bottom surface, and sidewalls are dimensioned such that the build plate is useable in a 3D printing device; and a recessed section formed through the top surface, wherein the recessed section is configured to be filled with a solid metal or metal alloy to provide a surface for forming a 3D printed object in the 3D printing device.
B22F 3/00 - Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sinteringApparatus specially adapted therefor
B22F 3/105 - Sintering only by using electric current, laser radiation or plasma
B33Y 30/00 - Apparatus for additive manufacturingDetails thereof or accessories therefor
B29C 64/153 - Processes of additive manufacturing using only solid materials using layers of powder being selectively joined, e.g. by selective laser sintering or melting
26.
Thermally decomposing build plate for facile release of 3D printed objects
Implementations of the disclosure are directed to thermally decomposable build plates that enable the facile release of 3D metal printed parts created by additive manufacturing. In some implementations, an additive manufacturing build plate comprises: a top surface, a bottom surface, and sidewalls comprised of a material, wherein the top surface, bottom surface, and sidewalls are dimensioned such that the build plate is useable in a 3D printing device; and a recessed section formed through the top surface, wherein the recessed section is configured to be filled with a solid metal or metal alloy to provide a surface for forming a 3D printed object in the 3D printing device.
Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44wt% and 83wt%, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5wt% to 44wt%, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.
B23K 35/02 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
B23K 35/26 - Selection of soldering or welding materials proper with the principal constituent melting at less than 400°C
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
28.
Low temperature melting and mid temperature melting lead-free solder paste with mixed solder alloy powders
Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.
Some implementations of the disclosure are directed to a solder preform, comprising: a solder alloy body, the solder alloy body comprising at least one opening; and a flux core embedded in the solder alloy body, the flux core comprising a thermochromic indicator, wherein during reflow soldering, the flux core comprising the thermochromic indicator is configured to flow out of the at least one opening of the solder alloy.
B23K 35/02 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
B23K 35/22 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
B23K 35/26 - Selection of soldering or welding materials proper with the principal constituent melting at less than 400°C
Some implementations of the disclosure are directed to a solder preform, comprising: a solder alloy body (100), the solder alloy body comprising at least one opening (140); and a flux core embedded in the solder alloy body, the flux core comprising a thermochromic indicator, wherein during reflow soldering, the flux core comprising the thermochromic indicator is configured to flow out of the at least one opening (140) of the solder alloy.
High reliability leadfree solder alloys for harsh service conditions are disclosed. In some embodiments, a solder alloy comprises 2.5-4.0 wt% Ag; 0.4-0.8 wt% Cu; 5.0-9.0 wt% Sb; 1.5-3.5 wt% Bi; 0.05-0.35 wt% Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a component comprising: a main ceramic body, and a side surface having disposed thereon an electrode and a thermal pad; a copper substrate; and a solder alloy electrically coupling the component and the copper substrate, wherein the solder alloy comprises: 2.5-4.0 wt% Ag; 0.4-0.8 wt% Cu; 5.0-9.0 wt% Sb; 1.5-3.5 wt% Bi; 0.05-0.35 wt% Ni; and a remainder of Sn. in some embodiments, an apparatus comprises: a light-emitting diode (LED) component; a Metal Core Printed Circuit Board (MCPCB); and a solder alloy electrically coupling the LED component and the MCPCB, wherein the solder alloy comprises: 2.5-4.0 wt% Ag; 0.4-0.8 wt% Cu; 5.0-9.0 wt% Sb; 1.5-3.5 wt% Bi; 0.05-0.35 wt% Ni; and a remainder of Sn.
High reliability leadfree solder alloys for harsh service conditions are disclosed. In some embodiments, a solder alloy comprises 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a component comprising: a main ceramic body, and a side surface having disposed thereon an electrode and a thermal pad; a copper substrate; and a solder alloy electrically coupling the component and the copper substrate, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn. In some embodiments, an apparatus comprises: a light-emitting diode (LED) component; a Metal Core Printed Circuit Board (MCPCB); and a solder alloy electrically coupling the LED component and the MCPCB, wherein the solder alloy comprises: 2.5-4.0 wt % Ag; 0.4-0.8 wt % Cu; 5.0-9.0 wt % Sb; 1.5-3.5 wt % Bi; 0.05-0.35 wt % Ni; and a remainder of Sn.
Some implementations of the disclosure are directed to a thermal interface material. In some implementations, a method comprises: applying a solder paste between a surface of a heat generating device and a surface of a heat transferring device to form an assembly; and reflow soldering the assembly to form a solder composite, wherein the solder composite provides a thermal interface between the heat generating device and the heat transferring device, wherein the solder paste comprises: a solder powder; particles having a higher melting temperature than a soldering temperature of the solder paste, wherein the solder paste has a volume ratio of solder powder to high melting temperature particles between 5:1 and 1:1.5; and flux.
A semiconductor device assembly includes: a semiconductor device; a heat exchanger; and a thermal interface material. In embodiments, the thermal interface material may contact a facing surface of the heat exchanger, the thermal interface material includes alloys that react with a bond enhancing agent to form an indium alloy layer in a portion of the thermal interface. In embodiments, a solid, solder preformed thermal interface material includes an indium metal and may be disposed on the first surface of the semiconductor device; and a liquid metal bond enhancing agent may be disposed on a first surface of the semiconductor device; and contacting a facing surface of the heat exchanger.
H01L 23/36 - Selection of materials, or shaping, to facilitate cooling or heating, e.g. heat sinks
H01L 23/373 - Cooling facilitated by selection of materials for the device
H01L 21/48 - Manufacture or treatment of parts, e.g. containers, prior to assembly of the devices, using processes not provided for in a single one of the groups or
H01L 23/367 - Cooling facilitated by shape of device
A SnAgCuSb-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics.
Some implementations of the disclosure are directed to low melting temperature (e.g., !iquidus temperature below 210°C) SnBi or Snln solder alloys. A SnBi solder alloy may consist of 2 to 60wt% Bi; optionally, one or more of: up to 16 wt% In, up to 4.5 wt% Ag, up to 2wt% Cu, up to 12 wt% 5b, up to 2.5wt% Zn, up to 1.5wt% Ni up to 1.5wt% Co, up to 1.5wt% Ge, up to 1.5wt% P, and up to 1,5wt% Mn; and a remainder of Sn. A Snln solder alloy may consist of: 8 to 20wt% In; optionally, one or more of: up to 12wt% Bi, up to 4wt% Ag, up to 5wt% 5b, up to 3wt% Cu, up to 2.5 wt% Zn, up to 1.5wt% Ni, up to 1.5wt% Co, up to 1.5wt% Ge, up to 1.5wt% P, and up to 1.5wt% Mn; and a remainder of Sn.
Some implementations of the disclosure are directed to low melting temperature (e.g., liquidus temperature below 210° C.) SnBi or Snln solder alloys. A SnBi solder alloy may consist of 2 to 60 wt % Bi; optionally, one or more of: up to 16 wt % In, up to 4.5 wt % Ag, up to 2 wt % Cu, up to 12 wt % Sb, up to 2.5 wt % Zn, up to 1.5 wt % Ni, up to 1.5 wt % Co, up to 1.5 wt % Ge, up to 1.5 wt % P, and up to 1.5 wt % Mn; and a remainder of Sn. A Snln solder alloy may consist of: 8 to 20 wt % In; optionally, one or more of: up to 12 wt % Bi, up to 4 wt % Ag, up to 5 wt % Sb, up to 3 wt % Cu, up to 2.5 wt % Zn, up to 1.5 wt % Ni, up to 1.5 wt % Co, up to 1.5 wt % Ge, up to 1.5 wt % P, and up to 1.5 wt % Mn; and a remainder of Sn.
Implementations of the disclosure describe techniques for eliminating or reducing hot tearing in via-in-pad plated over (VIPPO) solder joints by incorporating an adhesive into a printed circuit board assembly (PCBA). In an embodiment, the adhesive is an adhesive containing fluxing agent that prevents tearing by reducing a differential in thermal expansion caused by a coefficient of thermal expansion (CTE) mismatch between a plated metal of the VIPPO pads and the PCB substrate.
H05K 1/11 - Printed elements for providing electric connections to or between printed circuits
H05K 1/18 - Printed circuits structurally associated with non-printed electric components
H05K 3/32 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
Implementations of the disclosure describe techniques for eliminating or reducing hot tearing in via-in-pad plated over (VIPPO) solder joints by incorporating an adhesive into a printed circuit board assembly (PCBA). In an embodiment, the adhesive is an adhesive containing fluxing agent that prevents tearing by reducing a differential in thermal expansion caused by a coefficient of thermal expansion (CTE) mismatch between a plated metal of the VIPPO pads and the PCB substrate.
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
A lead-free solder preform includes a core layer and adhesion layer coated over surfaces of the core layer, where the preform delivers the combined merits from constituent solder alloys of the core and adhesion layers to provide both high temperature performance and improved wetting in high-temperature solder applications such as die attach. The core layer may be formed of a Bi Alloy having a solidus temperature above 260° C., and the adhesion layer may be formed of Sn, a Sn alloy, a Bi alloy, In, or an In alloy having a solidus temperature below 245° C. The solder preform may be formed using techniques such as: (1) electroplating a core ribbon with an adhesion material, (2) cladding an adhesion material foil onto a core ribbon, and/or (3) dipping a core ribbon in a molten adhesion alloy bath to allow thin layers of adhesion material to adhere to a core ribbon.
H01L 23/00 - Details of semiconductor or other solid state devices
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
41.
Fluxes effective in suppressing non-wet-open at BGA assembly
The disclosure describes techniques for eliminating or reducing non-wet open (NWO) defect formation by using a low activity flux to prevent a solder paste from sticking to ball grid array (BGA) solder balls during reflow soldering. The low activity flux may be configured such that: i) it creates a barrier that prevents the solder paste from sticking to the solder balls of the BGA; and ii) it does not impede the formation of solder joints during reflow. In implementations, a solid coating of the low activity flux may be formed over balls of the BGA, and the BGA may then be bonded to a PCB during reflow. In implementations, the balls of a BGA may be dipped in a low-activity creamy or liquid flux prior to reflow. In some implementations, the flux may applied on a solder paste printed on pads of the PCB, followed by placement of a BGA.
H01L 23/00 - Details of semiconductor or other solid state devices
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
A lead-free solder preform includes a core layer and adhesion layer coated over surfaces of the core layer, where the preform delivers the combined merits from constituent solder alloys of the core and adhesion layers to provide both high temperature performance and improved wetting in high-temperature solder applications such as die attach. The core layer may be formed of a Bi Alloy having a solidus temperature above 260°C, and the adhesion layer may be formed of Sn, a Sn alloy, a Bi alloy, In, or an In alloy having a solidus temperature below 245°C. The solder preform may be formed using techniques such as: (1) electroplating a core ribbon with an adhesion material, (2) cladding an adhesion material foil onto a core ribbon, and/or (3) dipping a core ribbon in a molten adhesion alloy bath to allow thin layers of adhesion material to adhere to a core ribbon.
C22C 28/00 - Alloys based on a metal not provided for in groups
C22F 1/16 - Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
B23K 35/00 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
The disclosure describes techniques for eliminating or reducing non- wet open (NWO) defect formation by using a low activity flux to prevent a solder paste from sticking to ball grid array (BGA) solder balls during reflow soldering. The low activity flux may be configured such that: i) it creates a barrier that prevents the solder paste from sticking to the solder balls of the BGA; and ii) it does not impede the formation of solder joints during reflow. In implementations, a solid coating of the low activity flux (476) may be formed over balls (475) of the BGA, and the BGA may then be bonded to a PCB during reflow. In implementations, the balls of a BGA may be dipped in a low- activity creamy or liquid flux prior to reflow. In some implementations, the flux may applied on a solder paste printed on pads of the PCB, followed by placement of a BGA.
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
A method of joining a semiconductor die to a passive heat exchanger can include applying a bond enhancing agent to a semiconductor device; creating an assembly that includes a thermal interface disposed on the semiconductor device such that a first major surface of the thermal interface material is in touching relation with the bond enhancing agent on the semiconductor device, and a heat exchanger disposed in touching relation with a second major surface of the thermal interface material; and reflowing the assembly such that the thermal interface bonds the heat exchanger to the semiconductor device. Embodiments can use the ability of indium to bond to a non- metallic surface to form the thermal interface, which may be enhanced by a secondary coating on either or both joining surfaces.
A method of joining a semiconductor die to a passive heat exchanger can include applying a bond enhancing agent to a semiconductor device; creating an assembly that includes a thermal interface disposed on the semiconductor device such that a first major surface of the thermal interface material is in touching relation with the bond enhancing agent on the semiconductor device, and a heat exchanger disposed in touching relation with a second major surface of the thermal interface material; and reflowing the assembly such that the thermal interface bonds the heat exchanger to the semiconductor device. Embodiments can use the ability of indium to bond to a non-metallic surface to form the thermal interface, which may be enhanced by a secondary coating on either or both joining surfaces.
H01L 21/48 - Manufacture or treatment of parts, e.g. containers, prior to assembly of the devices, using processes not provided for in a single one of the groups or
H01L 23/373 - Cooling facilitated by selection of materials for the device
46.
Apparatus and methods for creating a thermal interface bond between a semiconductor die and a passive heat exchanger
A method of joining a semiconductor die to a passive heat exchanger can include applying a bond enhancing agent to a semiconductor device; creating an assembly that includes a thermal interface disposed on the semiconductor device such that a first major surface of the thermal interface material is in touching relation with the bond enhancing agent on the semiconductor device, and a heat exchanger disposed in touching relation with a second major surface of the thermal interface material; and reflowing the assembly such that the thermal interface bonds the heat exchanger to the semiconductor device. Embodiments can use the ability of indium to bond to a non-metallic surface to form the thermal interface, which may be enhanced by a secondary coating on either or both joining surfaces.
H01L 21/44 - Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups
H01L 21/48 - Manufacture or treatment of parts, e.g. containers, prior to assembly of the devices, using processes not provided for in a single one of the groups or
H01L 21/50 - Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the groups or
H01L 23/367 - Cooling facilitated by shape of device
H01L 23/373 - Cooling facilitated by selection of materials for the device
Some implementations are directed to a burn-in solder preform including: a barrier layer to prevent thermally conductive material from adhering to a semiconductor component during burn-in testing; and a thermally conductive cladding layer attached to a portion of the barrier layer such that at least one dimension of the barrier layer extends past the thermally conductive cladding layer, where the thermally conductive cladding layer is attached over the barrier layer through continuous attachment or spot attachment. In some implementations, a method includes: placing the aforementioned burn-in solder preform between a test fixture and a semiconductor component; attaching a portion of the barrier layer of the burn-in solder preform to a head of the text fixture; and after attaching a portion of the barrier layer of the burn-in solder preform to the head of the test fixture, performing burn-in testing of the semiconductor component.
G01R 31/28 - Testing of electronic circuits, e.g. by signal tracer
G01K 7/01 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using semiconducting elements having PN junctions
H01L 23/532 - Arrangements for conducting electric current within the device in operation from one component to another including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body characterised by the materials
H01L 23/00 - Details of semiconductor or other solid state devices
H01L 23/488 - Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads or terminal arrangements consisting of soldered or bonded constructions
48.
SOLDER RIBBON WITH EMBEDDED MESH FOR IMPROVED RELIABILITY OF SEMICONDUCTOR DIE TO SUBSTRATE ATTACHMENT
A solder ribbon with an embedded mesh for improved reliability of semiconductor die to substrate attachment is described. A solder ribbon is embedded with a mesh having a melting point greater than that of the solder. The mesh is embedded through substantially the entire area of the solder ribbon. The embedded solder ribbon may then be wound onto a spool. During a reflow soldering process, the ribbon on the spool may be cut into segments that are placed between a semiconductor die and substrate to which the semiconductor die is to be bonded. When the semiconductor assembly is heated, the solder melts, but the mesh does not, allowing for uniform bondline thickness control.
A braided solder wire rope includes a first alloy including Bi—Ag, Bi—Cu, Bi—Ag—Cu, or Bi—Sb; and the second alloy including Sn, In Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Zn, Bi—Sn, Sn—In, Sn—Sb or Bi—In, such that the second alloy controls an interface reaction chemistry with various metallization surface finish materials without interfering with a high temperature performance of the first alloy. The first alloy may have a solidus temperature around 258° C. and at least the first alloy of the first wire and the second alloy of the second wire may be braided together.
A sintering paste includes solvent and nanomicrocrystallite (NMC) particles. Each NMC particle is a single crystallite having at least one dimension in the range of 1 nm to 100 nm and at least one dimension in the range of 0.1 μm to 1000 μm. The sintering paste may be used in a pressureless sintering process to form a low porosity joint having high bond strength, high electrical and thermal conductivity, and high thermal stability.
A lead-free solder wire includes a core wire with a first alloy and a shell coating layer with a second alloy. The first alloy may be composed of Bi—Ag, Bi—Cu, Bi—Ag—Cu, or Bi—Sb; and the second alloy may be composed of Sn, In Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Zn, Bi—Sn, Sn—In, Sn—Sb or Bi—In, such that the shell coating layer is applied to a surface of the core wire. In another implementation, the lead free solder wire may include a first wire with a first alloy and a second wire with a second alloy. The first alloy may be composed of Bi—Ag, Bi—Cu, Bi—Ag—Cu, or Bi—Sb; and the second alloy may be composed of Sn, Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Zn, Bi—Sn, Sn—In, Sn—Sb or Bi—In, such that the first alloy of the first wire and the second alloy of the second wire are braided together.
B23K 31/02 - Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by any single one of main groups relating to soldering or welding
B23K 35/26 - Selection of soldering or welding materials proper with the principal constituent melting at less than 400°C
B23K 35/02 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
A lead-free solder alloy having a low melting temperature and low yield strength is disclosed. The solder alloy includes 5.0-20.0 wt. % of indium (In), 1.0-5.0 wt. % of silver (Ag), 0.25-2.0 wt. % of copper (Cu), 0.1-0.5 wt. % of zinc (Zn), and a remainder of tin (Sn). In implementations, a sulfur compound may be included in a concentration of 100 ppm to 500 ppm in the alloy to prevent oxidation of zinc and indium on the surface of the alloy. The solder alloy is particularly useful for but not limited to solder on pad applications in first level interconnect semiconductor device packaging.
H01L 23/00 - Details of semiconductor or other solid state devices
B23K 35/26 - Selection of soldering or welding materials proper with the principal constituent melting at less than 400°C
H01B 1/02 - Conductors or conductive bodies characterised by the conductive materialsSelection of materials as conductors mainly consisting of metals or alloys
A SnAgCuSb-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics. An additive selected from 0.1-2.5 wt. % of Bi and/or 0.1-4.5 wt. % of In may be included in the solder alloy.
A SnAgCuSb-based Pb-free solder alloy is disclosed. The disclosed solder alloy is particularly suitable for, but not limited to, producing solder joints, in the form of solder preforms, solder balls, solder powder, or solder paste (a mixture of solder powder and flux), for harsh environment electronics. An additive selected from 0.1-2.5 wt.% of Bi and/or 0.1-4.5 wt.% of In may be included in the solder alloy.
A solder paste consists of an amount of a first solder alloy powder between 44wt% to less than 60wt%; an amount of a second solder alloy powder between greater than Owt% and 48wt%; and a flux; wherein the first solder alloy powder comprises a first solder alloy that has a solidus temperature above 260°C; and wherein the second solder alloy powder comprises a second solder alloy that has a solidus temperature that is less than 250°C. In another implementation, the solder paste consists of an amount of a first solder alloy powder between 44wt% and 87wt%; an amount of a second solder alloy powder between 13wt% and 48wt%; and flux.
C22C 13/02 - Alloys based on tin with antimony or bismuth as the next major constituent
C22C 28/00 - Alloys based on a metal not provided for in groups
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
C22C 30/02 - Alloys containing less than 50% by weight of each constituent containing copper
C22C 30/04 - Alloys containing less than 50% by weight of each constituent containing tin or lead
C22C 30/06 - Alloys containing less than 50% by weight of each constituent containing zinc
56.
Voiding control using solid solder preforms embedded in solder paste
Methods are provided for controlling voiding caused by gasses in solder joints of electronic assemblies. In various embodiments, a preform can be embedded into the solder paste prior to the component placement. The solder preform can be configured with a geometry such that it creates a standoff, or gap, between the components to be mounted in the solder paste. The method includes receiving a printed circuit board comprising a plurality of contact pads; depositing a volume of solder paste onto each of the plurality of contact pads; depositing a solder preform into each volume of solder paste; placing electronic components onto the printed circuit board such that contacts of the electronic components are aligned with corresponding contact pads of the printed circuit board; and reflow soldering the electronic components to the printed circuit board.
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
H01L 21/48 - Manufacture or treatment of parts, e.g. containers, prior to assembly of the devices, using processes not provided for in a single one of the groups or
57.
METHODS AND COMPOSITIONS FOR FORMING SOLDER BUMPS ON A SUBSTRATE WITH RADIATION CURABLE OR THERMAL CURABLE SOLDER FLUX
Methods of forming solder bumps or joints using a radiation curable, thermal curable solder flux, or dual curable solder flux are disclosed. The method includes applying a liquid solder flux 130 that is radiation curable or thermal curable to a substrate 110 such that the solder flux covers contact padsl20 on the substrate; placing solder balls 140 on the contacts pads covered with the radiation curable or thermal curable solder flux; heating the substrate to join the solder balls to the contact pads, thereby forming solder bumps or solder joints 150; and curing the liquid solder flux by applying radiation or heat to the substrate, thereby forming a solid film 160. The solder flux includes radiation curable, thermally curable, or dual curable materials that aid formation of solder bumps or joints before the solder flux is cured; and are curable to form a solid material by the application of radiation or heat.
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
B23K 1/20 - Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating
A solder paste consists of an amount of a first solder alloy powder between 44 wt % to less than 60 wt %; an amount of a second solder alloy powder between greater than 0 wt % and 48 wt %; and a flux; wherein the first solder alloy powder comprises a first solder alloy that has a solidus temperature above 260° C.; and wherein the second solder alloy powder comprises a second solder alloy that has a solidus temperature that is less than 250° C. In another implementation, the solder paste consists of an amount of a first solder alloy powder between 44 wt % and 87 wt %; an amount of a second solder alloy powder between 13 wt % and 48 wt %; and flux.
C22C 30/04 - Alloys containing less than 50% by weight of each constituent containing tin or lead
C22C 30/02 - Alloys containing less than 50% by weight of each constituent containing copper
C22C 30/06 - Alloys containing less than 50% by weight of each constituent containing zinc
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
A solder paste consists of an amount of a first solder alloy powder between 60 wt % to 92 wt %; an amount of a second solder alloy powder greater than 0 wt % and less than 12 wt %; and a flux; wherein the first solder alloy powder comprises a first solder alloy that has a solidus temperature above 260° C.; and wherein the second solder alloy powder comprises a second solder alloy that has a solidus temperature that is less than 250° C.
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
60.
Low void solder joint for multiple reflow applications
Methods and apparatus are provided for attaching a heat spreader to a die and includes disposing a solder thermal interface material between a first surface of a die and a first surface of a heat spreader without disposing a liquid flux between the die and the heat spreader to form an assembly, wherein at least one of the first surface of the die and a first surface of the heat spreader have disposed thereon a metallization structure comprising a transition layer and a sacrificial metallization layer, the sacrificial metallization layer disposed as an outer layer to the metallization structure adjacent the solder thermal interface material; and heating the assembly to melt the thermal interface and attach the die to the heat spreader.
B23K 20/22 - Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded
B23K 35/00 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
H01L 21/50 - Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the groups or
H01L 23/00 - Details of semiconductor or other solid state devices
H01L 23/36 - Selection of materials, or shaping, to facilitate cooling or heating, e.g. heat sinks
H01L 23/373 - Cooling facilitated by selection of materials for the device
H01L 23/10 - ContainersSeals characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
61.
Heat dissipating paint with high thermal radiating capability
A high emissive paint comprises organic materials with different functional groups, one or more inorganic materials, and optionally other paint property adjusting agents. The infrared absorption range of the paint derives from organic functional groups, such as C—C, C—H, N—H, C—N, C—O and C—X groups, and the one or more inorganic materials. One or more inorganic materials may also be present as micro- or nano-sized particles.
Λ high emissive paint comprises organic materials with different functional groups, one or more inorganic materials, and optionally other paint property adjusting agents. The infrared absorption range of the paint derives from organic functional groups, such as C-C, C-H, N-H, C-N, C-0 and C-X groups, and the one or more inorganic materials. One or more inorganic materials may also be present as micro- or nano-sized particles.
A Sn-Ag-Cu-based lead-free solder alloy and solder joints thereof with superior drop shock reliability are disclosed. The solder comprises between greater than 0 wt.% and less than or equal to about 1.5 wt.% Ag; between greater than or equal to about 0.7 wt.% and less than or equal to about 2.0 wt.% Cu; between greater than or equal to about 0.001 and less than or equal to about 0.2 wt.% Mn; and a remainder of Sn.
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
64.
MN doped SN-base solder alloy and solder joints thereof with superior drop shock reliability
A Sn—Ag—Cu-based lead-free solder alloy and solder joints thereof with superior drop shock reliability are disclosed. The solder contains between greater than 0 wt. % and less than or equal to about 1.5 wt. % Ag; between greater than or equal to about 0.7 wt. % and less than or equal to about 2.0 wt. % Cu; between greater than or equal to about 0.001 and less than or equal to about 0,2 wt. % Mn; and a remainder of Sn.
A method is provided for the forming of a metallic solder joint without a liquid flux to create a solder joint that has minimal voids and can be reflowed multiple times without void propagation. This process can be done for any solder alloy, and is most specifically used in the application of first level thermal interface in a IC or micro processor or BGA microprocessor.
B23K 33/00 - Specially-profiled edge portions of workpieces for making soldering or welding connectionsFilling the seams formed thereby
B23K 31/02 - Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by any single one of main groups relating to soldering or welding
H01L 23/00 - Details of semiconductor or other solid state devices
H01L 23/36 - Selection of materials, or shaping, to facilitate cooling or heating, e.g. heat sinks
H01L 23/373 - Cooling facilitated by selection of materials for the device
H01L 23/10 - ContainersSeals characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
H01L 21/50 - Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the groups or
66.
LOW VOID SOLDER JOINT FOR MULTIPLE REFLOW APPLICATIONS
A method is provided for the forming of a metallic solder joint without a liquid flux to create a solder joint that has minimal voids and can be re flowed multiple times without void propagation. This process can be done for any solder alloy, and is most specifically used in the application of first level thermal interface in a IC or micro processor or BGA microprocessor.
H01L 21/60 - Attaching leads or other conductive members, to be used for carrying current to or from the device in operation
H01L 23/488 - Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads or terminal arrangements consisting of soldered or bonded constructions
A process of making efficient metal bump bonding with relative low temperature, preferably lower than the melting point of Indium, is described. To obtaining a lower processing temperature (preferred embodiments have a melting point of <100° C.), a metal or alloy layer is deposited on the indium bump surface. Preferably, the material is chosen such that the metal or alloy forms a passivation layer that is more resistant to oxidation than the underlying indium material. The passivation material is also preferably chosen to form a low melting temperature alloy with indium at the indium bump surface. This is typically accomplished by diffusion of the passivation material into the indium to form a diffusion layer alloy. Various metals, including Ga, Bi, Sn, Pb and Cd, that can be used to form a binary to quaternary low melting point alloy with indium. In addition, diffusion of metal such as Sn, Sn—Zn into Ga—In alloy; Sn, Cd, Pb—Sn into Bi—In alloy; Cd, Zn, Pb, Pb—Cd into Sn—In alloy can help adjust the melting point of the alloy.
H01B 1/08 - Conductors or conductive bodies characterised by the conductive materialsSelection of materials as conductors mainly consisting of other non-metallic substances oxides
H01L 23/00 - Details of semiconductor or other solid state devices
A process of efficient metal bump bonding with relatively low temperatures, preferably lower than the melting point of indium, is described. To obtain a lower processing temperature (preferred embodiments have a melting point of < 100°C), a metal or alloy layer (138) is deposited on the indium bump (134) surface. Preferably, the material is chosen such that the metal or alloy forms a passivation layer that is more resistant to oxidation than the underlying indium material. The passivation material is also preferably chosen to form a low melting temperature alloy with indium at the indium bump (134) surface. This is typically accomplished by diffusion of the passivation material into the indium to form a diffusion layer alloy. Various metals, including Ga, Bi, Sn, Pb and Cd, can be used to form a binary to quaternary low melting point alloy with indium. In addition, diffusion of metal such as Sn, Sn-Zn into Ga-In alloy; Sn, Cd, Pb-Sn into Bi-In alloy; Cd, Zn, Pb, Pb-Cd into Sn-In alloy can help adjust the melting point of the alloy.
H01L 21/60 - Attaching leads or other conductive members, to be used for carrying current to or from the device in operation
H01L 23/485 - Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads or terminal arrangements consisting of lead-in layers inseparably applied to the semiconductor body consisting of layered constructions comprising conductive layers and insulating layers, e.g. planar contacts
A solder paste comprises an amount of a first solder alloy powder between about 60 wt% to about 92 wt%; an amount of a second solder alloy powder greater than 0 wt% and less than about 12 wt%; and a flux; wherein the first solder alloy powder comprises a first solder alloy that has a solidus temperature above about 260°C; and wherein the second solder alloy powder comprises a second solder alloy that has a sol idus temperature that is less than about 250°C.
A composition for a highly reliable thermal interface materials includes: (A) moisture-resistant polymer with a water permeability coefficient preferably less than 10-11 cm3 (STP) cm/cm2 S Pa, (B) gas barrier polymer having oxygen permeability coefficient preferably less than 10-14 cm3 (STP) cm/cm2 S Pa, (C) antioxidant, (D) thermal conductive filler and ( E) other additive or optional materials. The thermal interface materials placed in between the thermal generating and dissipating devices can effectively barrier water and oxygen penetration, preventing the thermal fillers from degradation and improving the reliability of the devices.
A solder paste comprises an amount of a first solder alloy powder between about 60 wt % to about 92 wt %; an amount of a second solder alloy powder greater than 0 wt % and less than about 12 wt %; and a flux; wherein the first solder alloy powder comprises a first solder alloy that has a solidus temperature above about 260° C.; and wherein the second solder alloy powder comprises a second solder alloy that has a solidus temperature that is less than about 250° C.
H01L 23/00 - Details of semiconductor or other solid state devices
H05K 3/34 - Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
Various embodiments of the invention provide laminate composite preform foils for high-temperature Pb-free soldering applications. The laminate composite preform foil is composed of a high-melting, ductile metal or alloy core layer and a low-melting solder coating layer at either side of the core layer. During soldering, the core metal, liquid solder layer, and substrate metals react and consume the low-melting solder phase to form high-melting intermetallic compound phases (IMCs). The resultant solder joint is composed of a ductile core layer sandwiched by the IMCs layers at substrate sides. The joint has a much higher remelt temperature than the original melting temperature of the initial solder alloy coating, allowing subsequent mounting of packaged devices.
B23K 31/02 - Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by any single one of main groups relating to soldering or welding
Various embodiments of the invention provide laminate composite preform foils for high-temperature Pb-free soldering applications. The laminate composite preform foil is composed of a high-melting, ductile metal or alloy core layer and a low-melting solder coating layer at either side of the core layer. During soldering, the core metal, liquid solder layer, and substrate metals react and consume the low-melting solder phase to form high-melting intermetallic compound phases (IMCs ). The resultant solder joint is composed of a ductile core layer sandwiched by the IMCs layers at substrate sides. The joint has a much higher remelt temperature than the original melting temperature of the initial solder alloy coating, allowing subsequent mounting of packaged devices.
A solder preform has gaps extending from the boundary of preform towards the preform center. During reflow soldering, the gaps close from the center towards the boundary. This allows flux and gasses to escape the interface between the solder and the substrate. Particularly, flux accumulates in the spaces formed by the gaps and is forced to the edge of the solder preform as the gap closes. In further embodiments, channels are formed on one or both surfaces of the solder preform. In addition to further assisting in the escape of gas and flux during reflow, the channels and gaps increase the effectiveness of oxygen purging using inert or reducing gasses in the reflow chamber. Additionally, the channels and gaps increase the effectiveness of vacuum solder.
B23K 35/14 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape not specially designed for use as electrodes for soldering
B23K 31/02 - Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by any single one of main groups relating to soldering or welding
Materials having increased mobility after heating are disclosed. In one particular exemplary embodiment, the materials may be realized as a material which has reduced apparent molecular weight and/or viscosity and thus increased mobility after a heating process, and which consequently allows material residue to be more easily removed during subsequent cleaning processes. Such a material may be useful in any industrial process which requires heating the material followed by removing material residue.
B23K 35/22 - Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
B23K 35/24 - Selection of soldering or welding materials proper
76.
Lead-free solder alloys and solder joints thereof with improved drop impact resistance
Lead-free solder alloys and solder joints thereof with improved drop impact resistance are disclosed. In one particular exemplary embodiment, the lead-free solder alloys preferably contain 0.0-4.0 wt. % of Ag, 0.01-1.5 wt. % of Cu, at least one of the following additives: Mn in an amount of 0.001-1.0 wt. %, Ce in an amount of 0.001-0.8 wt. %, Y in an amount of 0.001-1.0 wt. %, Ti in an amount of 0.001-0.8 wt. %, and Bi in an amount of 0.01-1.0 wt. %, and the remainder of Sn.
patents
