Material Alloying, stamping, plating and assembly all produced in-house.
Combo-Lids® / FLA’s (Frame Lid Assembly)
The Combo-Lid® continues to be a leading choice for hermetically sealing electronic packages. The base material is either Kovar™ or Alloy 42, which is electroplated with nickel to ensure a clean particulate free surface. The lids are then electroplated with a gold flashing and subsequently tack welded to a solder preform. The nickel electroplate layer serves as a very effective barrier to corrosion, while the gold electroplate layer provides a readily solderable surface.
Lid Composition: Kovar or Alloy 42 with Nickel electroplate MIL-38510 50-350 micro inch. Gold electroplate MIL-G-45204B Type III, Grade A. Length and width dimension tolerance +/-.003". Thickness dimension tolerance is +/-.001" with Flatness <.001" for lids <.500" or .002 for lids >.500", burrs <.001".
Lid Frame
Composition 80 +/- 1% Au, balance Sn with total impurities <149 ppm. Length and width dimension tolerance +/-.003". Thickness dimension tolerance +/-.0003"
Tack Weld Assembly Three integral welds, Alignment +/-.005", Weld Splatter <.003"
Design Guidelines
Williams can help you with the design of the cover lid, frame size and related tooling, and suggest process parameters to ensure maximum line yields. We recommend the cover OD be .025" less than the package seal ring OD, and the ID of the preform be .025" larger than the package seal ring ID, provided a minimum solder width of .025" is maintained. The outside dimensions of the lid and preform are usually the same.
Combo-Lid ® Processing Information
We recommend a typical clip force of 0.9-2 lbs. Clip pressure varies depending on lid size, preform thickness, lid flatness, and seal-ring flatness. Typical sealing profiles allow for 2-5 minutes above 280 C (melting temperature) with a peak temperature not exceeding 340 C in dry nitrogen, or hydrogen.
Mechanism for Sealing Micro Electronic Packages
Micro electronic packages sealed with Combo-Lids®: chip carriers, side braze, PGA, dual in-line, and flat packs.
The above description refers to our standard products. Plating properties can be modified to meet specific needs.
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