HYBRID SOLDER BALL AND PIN GRID ARRAY CIRCUIT BOARD INTERCONNECT SYSTEM AND METHOD

摘要

A circuit board interconnect system (30) includes a carrier board (32) with a hybrid solder ball and pin grid array. A plurality of electrically conductive pins (34) extend through the carrier board (32) and are arranged in rows and columns to form a grid array. A first circuit board (10) such as a multi-chip module (MCM) board has a plurality of conductive pads or traces formed on a lower surface thereof that are arranged to form a complementary grid array, i.e., the spacing and location of the conductive pads or traces corresponds to the spacing and location of the pins. A plurality of solder balls (38) are provided with each ball (38) being positioned on top of a corresponding pin (34) so that each solder ball (38) forms a solder connection between a pin (34) and a corresponding pad or trace. A second circuit board (12) such as a computer mother board has a pin connector (17) mounted on an upper surface thereof for individually receiving and providing electrical connection with each of the pins (34). After reflow, the solder balls (38) wrap around the side walls of the heads of the pins and the side walls of the pads. The resulting generally spherical solder connections are therefore stronger than conventional elongated fillet connections.