Module Pinning Enhancement
Original Publication Date: 1984-Aug-01
Included in the Prior Art Database: 2005-Feb-04
As substrates get larger, pin insertion is complicated by non-uniform shrinkage of the fired ceramic which leaves pinholes off the dimensional grid. When tooling gravity feeds from a perfect grid pattern of pin feed tubes, there is little room for misalignment or the pins will not drop in place and the substrate cannot be pinned. The following technique employs alternate material of equivalent strength, electrical and thermal conductivity, but as much as 20% smaller diameter (.016" vs. .020"). The smaller diameter pins allow much greater freedom in pin insertion with a resultant yield enhancement. Two alternate materials used are copper and steel, with either a copper sleeve and steel core or a copper sleeve, steel ring, and copper core.