Fixture and method for attaching components

摘要

A fixture (10) for bonding multiple components together includes a bottom plate (20), a middle plate (22) and a top plate (24). The plates (20), (22) and (24) are aligned by dowels (26) and clamps (30). Bottom plate (20) has a rectangular pocket (32) for holding heat sink (14) and alignment pins (34) for locating plastic pin grid array (PPGA) package (12) over the heat sink (14). An annular projection (40) covered with a conformal pad (42) extends from bottom surface (44) of the middle plate (22). Dowel (50) extends through openings (46) and (36) in the top and middle plates (24) and (22) to apply pressure to chip (16). A first spring (56) is mounted on the dowel (50) and compressed between the top plate (24) and a snap ring (58) to provide pressure from the dowel (50) on the chip (16). A second, larger diameter spring (60) is compressed between the middle plate (22) and the top plate (24) to provide pressure from the middle plate (22) on the PPGA (12). Cartridge heaters (62) are embedded in the bottom plate (20) to provide heat for epoxy or solder bonding. A thermocouple (64) monitors temperature at the bottom plate (20).