Prevention of Shorting in Multilayer Ceramic Modules
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
This process uses unpunched vias, as electrical insulation, in lieu of dummy chips to prevent cross-via shorting that could be caused by radial finger contacts. Certain multilayer ceramic (MLC) module designs use a one-piece radial finger contact (RFC) to transfer heat from the chips to the ceramic cap and subsequently to the heatsink. This design requires that unused chip sites be populated with dummy chips to prevent RFC electrical shorting between vias. Instead of using dummy chips, the unused sites can be electrically insulated by not punching vias in specific sites, making them electrically discontinuous. Changing the metallizing (screening) procedure is unnecessary. The metallized pattern is applied, as usual, over the non-punched via area; however, would not be electrically connected to the layer below.