Solderability implications of burn-in on side-brazed packages
Abstract
Devices for military applications undergo accelerated operating life stressing or "Burn-In (BI)" prior to final testing. Ceramic Dual In-Line Packages (CD) have one less test manufacturing step since its leads (or terminations) are dipped in solder prior to BI. In a move toward reducing device handling and improving cycle time, an attempt was made to emulate the CERDIP procedure to Side Brazed (SB) and Metal Can (MC) packages. Initial runs show both SB and MC's shiny solder finish became rough and dull and failed a standard Solderability test after BI. An examination of the leads showed SB and MC differ from CD in that it has an additional Nickel-layer on top of the base metal. This paper aims to determine how the additional layer of Ni in SB (and MC) induced a rough surface morphology and caused Solderability test failures.