Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Intel Corporation (INTC) -- Ignore unavailable to you. Want to Upgrade?

To: Jim McMannis who wrote (52885)	4/14/1998 12:20:00 PM
From: Paul Engel	Respond to of 186894

Jim - Re: "What precious/base metals do they use in chip manufacturing?" In wafer fabrication, Silicon and Polysilicon (not a metal), Aluminum (with small amounts of copper and/or silicon) Tungsten, and Titanium are the "main metals" used. For the C4 process, Chromium, Copper, lead, tin, antimony (depending upon whose C4 process) are used with perhaps a small amount of gold. In assembly, aluminum and gold wire (non C-4) are used for wire bonding and small amounts of gold are used on substrates. Substrates themselves use different metals depending upon the substrate. For example, a multi-layered ceramic (Al2O3) PGA package will use alloy 42 pins/leads (Iron-nickel) with nickel plating and a final layer of gold - about 40 to 60 micro inches thick. Internally, the interconnections are usually tungsten thick films, with a small amount of gold on the finger tips for bonding. Cheaper substrates - plastic PGA - use FR 4 or BT-Epoxy with copper plated traces and gold flash over the copper for interconnect. Paul