Method and apparatus for welding printed circuits
AssigneeCedal Equipment Srl
InventorBruno Ceraso
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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.
Claims7
Method for induction bonding of a printed circuit multilayer stack (18), wherein the stack comprises a plurality of conducting layers (19) incorporating the printed circuit layout (21), which are separated from each other by a plurality of insulating layers (20) made of dielectric material impregnated with resin, spacers (25) being arranged along the edge of the conducting layers (19) in order to keep them spaced apart along the edge, wherein the method comprises the step of inducing a magnetic flux at predetermined locations of the multilayer stack (18) where conducting elements (25) are provided in order to achieve the localized heating of the resin, characterized in that the magnetic flux is induced in a plurality of spacers (25).
Bonding method according to any of the preceding claims, wherein each induced flux is of the variable type with a frequency ranging from 18 kHz to 30 kHz, preferably equal to about 24 kHz.
Bonding method according to any of the preceding claims, wherein the conducting spacers (25) have a circular or polygonal shape.
Dependencies are inferred from the claim text.