3-D solid modeling for assembly design

The authors describe a solid model 3-D CAD (computer-aided design) tool that was used by a concurrent engineering integrated circuit assembly team. Parameter and tolerance designs were established in the design phase of the ceramic pin grid array package cavity. The results supported standard wire bond technology for 5 mil pitch chip pads and suggest the choice of an orthogonal pad design as the most robust package and layout. The ability to illustrate various conditions by changing process and piece part tolerances before tooling was the key to assuring a design for maximum manufacturability