Hold-down collar for attachment of IC substrates and elastomeric material to PCBs

摘要

A land grid array package (21) or a ball grid array package is electrically connected by means of an elastomeric type layer (26) containing alternating elements of conductive and non-conductive silicone, to a printed wire board (31) or motherboard. A hold-down collar (36) engages the peripheral edges (24) of the package (21) and snaps into holes (33) in the board (31) in such manner as to create pressure on the elastomeric layer (26), causing the layer (26) to compress and create through-going electrical paths between exposed lands (22) or conductive elements on the bottom of the package (21) and exposed conductive elements (32) on the wiring board (31). In one embodiment, solder balls adhere to the exposed conductive elements on the bottom of the package. In this embodiment the collar is initially in two pieces which are fitted together to engage both the top and bottom edges of the substrate.