Abstract

The invention regards a press for soldering multilayer stacks for printed circuits, with an outer muffle that encloses soldering chambers where multilayer stacks are arranged to be heated, inducing a magnetic flux. For such purpose, the press is provided with an inductor having winding form which is arranged on a mobile piston adapted to apply a force on the multilayer stack, such to generate a magnetic flux at its interior that is spatially uniform and regular over time.

IPC Classes  ?

• B30B 15/06 - Platens or press rams
• B30B 1/42 - Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen by magnetic means, e.g. electromagnetic
• H05B 6/36 - Coil arrangements
• H05K 3/46 - Manufacturing multi-layer circuits

Abstract

In manufacturing multilayer plastic laminates for printed circuits, a press with two surfaces exerts pressure under vacuum on a stack of laminates, the packs, alternated with separator plates made of anodized aluminum. The packs include prepreg layers. The metalizations present on the two sides of each pack are portions of a copper strip repeatedly folded 180° around each pack and each separator plate. A strong current circulates in the copper strip which heats the strip with resistive behavior: the heat causes the close fixing of the various layers. An auxiliary heater is applied to each surface of the press by element of an interposed insulating plate. This includes an aluminum plate with equidistant longitudinal holes containing the same number of armored candle-like resistors, connected in parallel. A main power supply provides direct current to the copper strip, two secondary power supplies provide alternating current to the two auxiliary heaters.

IPC Classes  ?

• H05K 3/10 - Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
• H05K 3/46 - Manufacturing multi-layer circuits
• B32B 7/12 - Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• B32B 29/00 - Layered products essentially comprising paper or cardboard

Abstract

The invention relates to a method for bonding stacked layers (19, 20) for making printed circuits, by electromagnetic induction. In particular, a magnetic flux is locally induced at a plurality of conducting spacers (25) provided along a peripheral area (22) of the multilayer stack (18). By this method, it is possible to induce magnetic fluxes with opposite sign in individual areas of the peripheral area, thus achieving the maximum energy efficiency during the bonding process. The invention further comprises an induction head and a bonding apparatus for performing the method.

IPC Classes  ?

• H05K 3/46 - Manufacturing multi-layer circuits

Goods & Services

Moulds and machinery for printed circuits.