Flat Packs (Forgotten PC History)

Scanning ????????: I've seen a few things with flat packs and have had a few of the little critters myself. Most were from Fairchild. Some didn't have the maker's logo and some weren't marked at all. THey were typically white ceramic packages with gold lids and gold leads. They are either square, rectangular or round, with 2, 4, 6, 8--up to 20 leads. I'm pretty sure that most of the stuff was space grade and came from satellite and missile projects. I found them in analog, digital and analog/digital gear, often in UHF and microwave RF stuff, sometimes mixed with tubes, either soldered to 2oz gold plated copper PCB's, or spot welded onto gold plated posts or small blocks, or in one case, trimmed and welded in an unusual way to very heavy copper on a Teflon PCB. Wherever they were PCB mounted, whether soldered or welded, there usually was a hole cut out for them. Sometimes the solder was some gold alloy. THe leads were typically not bent as SMT components are now. I've also seen large arrays of them attached to leads that came out of PCB layers. These PCB's were covered with solid gold-plated copper on both sides, with the circuitry on the layers inside. They still exist, in some form, at least. The most common form seems to be as medium powered microwave (above 500MHz) RF transistors, arrays, amplifiers or LSI/ASIC radios. Some leads are modified to serve as heatsinks. It seems that they are caught up in the trend toward leadless packages as well, so they will probably go away too. They are almost effective as shuriken... -- jd