Fine pitch pad array carrier sockets for multichip modules

A project is currently under way to develop two pad array carrier (PAC) multichip modules using Motorola´s H4C123 ASIC family as a test vehicle. A brief summary of Motorola´s multichip module test vehicle is first presented. Then, a comparison of three different connector technologies is provided. A limited number of socket manufacturers were evaluated. The main parameters considered from vendor to vendor were contact pitch, contact repairability, clamping force, resistance per contact, inductance per contact, capacitance per contact, insulator resistance, heat sink attach area, availability of comprehensive test data performed on the product, and cost. A discussion of design considerations is included. Two different socket technologies were selected for a 50 and a 100 mil pitch multichip module