WILLIAMS Advanced Materials 

Williams Advanced Materials manufactures a variety of hermetic lids for the semiconductor, hybrid/micro electronics and optical markets. In the early 1980’s Williams began tack welding its own frames and lid components together for what has become the traditional Combo-Lid®. Throughout the years Williams has partnered with various companies to develop new hermetic lid styles to meet the changes in packaging designs and sizes.

The Williams hermetic lid product line includes: Micro Lids™ for packages smaller than .300 square, Seam Seal-Lids™ for sealing heat sensitive electronics, Solder Reflow-Lids™ , a cost alternative to the Combo-Lid® and our newest lid, the Visi-Lid™ for optical packages.

Williams is the leading Combo-Lids® manufacturer in the world with operations in North America, Singapore and the Philippines in support of this product line.

Hermetic lids are available in a variety of sizes and designs including the traditional Combo-Lid® and low cost MicrolidTM.

	Extensive tooling library and in-house tooling capabilities
	State-of-the-Art Analytical Capabilities
	ISO 9002 Certified

Lid Composition
Composition Kovar or Alloy 42. 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 +/-.001". Flatness <.001" for lids <.500" or .002 for lids >.500". Burr <.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

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.

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 degree C in dry nitrogen, or hydrogen.    

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.    

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.

Window Materials
Window substrates suitable for ultraviolet, visible and infrared applications are available. Typical materials include: BK-7, Sapphire, Germanium, Silicon, other materials are available.
Anti-Reflective Coating
Single layer or multi-layer material systems, custom designed to meet customer transmission requirements..
Select Solders
Williams is an industry leader in developing and manufacturing solder alloys for Optoelectronic applications. See the chart below for the typical materials. Others are also available.

Visi-Lid™ is an optical assembly designed to pass light at specified wavelengths. In its simplest form, the assembly consists of an A/R coated and glass metallized window of sapphire, silicon or germanium with a solder frame tack welded to the metallized portion. More complex assemblies will require the metallized windows to be sealed to a plated Kovar frame, with either a solder preform being tack welded to the kovar frames or left bare for seam sealing. These assemblies can be used to hermetically seal various device packages.

Glass inset on plated kovar frame, configured for seam welding

Configured for direct glass to package solder seal

Window substrates suitable for infrared, ultraviolet, and visible light applications are available. Typical materials for windows: Sapphire, BK-7, Germanium, and Silicon; other materials are available.

Single layer or multi-layer material systems, custom designed to meet customer transmission requirements. Visible light, ultraviolet, and infrared coatings are available

Williams is an industry leader in developing and manufacturing solder alloys for Optoelectronic applications. See the chart below for the typical materials. Others are also available.

The above description is of our standard products. Properties can be modified to meet specific needs.

Williams Advanced Materials developed the Micro-Lid™ in the late 1990’s as a cost alternative to the traditional Combo-Lid.

For package designs .300 inches square or smaller.

Base metal is A-42 per ASTM F-30-90.  The A42 is plated with 80-100 micro inches of sulfimate Ni followed by 35-50 micro inches of Au.  It is clad on one side with 80Au, 20Sn at .0012+/-.0002 thick.  An Au over-flash is added to cover the edges to ensure that one side can be distinguished from the other.

Williams offers SeamSeal-Lids TM in a variety of sizes and configurations to meet your needs. We have a large library of available tools built specifically to stamp kovar lids. Typical dimensions for the lids range from .250 square to .060 square.

The above description is of our standard products.  Plating properties can be modified to meet specific needs.

SeamSeal-Lids™ are also know as an Electroless Ni Lids.

This type of kovar lids are designed specifically to seal packages containing heat sensitive electronics.

Base material A-42 or kovar lids, plated with 50-200 micro inches of Electroless Ni.  A variety of Phosphorous levels are available; Low 1-4% semi bright deposit, Mid 3-9% very bright deposit, and High 10.5-12 dull deposit.  Corrosion resistance increases as Phosphorous level increases.

Solder Reflow Lids are available with non-precious solders, eliminating any of the precious metals in the package. The traditional Combo-Lid is manufactured by tack welding a gold tin solder preform to a plated Kovar lid. The Solder Reflow Lid is manufactured in an atmosphere controlled furnace by melting a non precious solder onto the surface of a plated strip. The strip is then stamped into parts that meet the customer’s dimensional specifications.

A hermetic lid with non-precious solder
The Solder Reflow Lid™ is a cost effective alternative to a Combo-Lid® for smaller lids, typically less than 0.2" by 0.2".