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Black Chromium as a Solder Dam

IP.com Disclosure Number: IPCOM000051058D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10

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Related People

Block, ML Hoffman, HS Kung, P Starr, SG [+details]


In the manufacturing of substrates for the mounting of integrated circuit chips, top surface metallization is applied to the substrate. Conventionally this metallization includes successively depositing a bottom layer of Cr, an intermediate layer of Cu, and a top layer of Cr. When the chip or chips are to be soldered by flip-chip bonding techniques, the top layer of Cr is removed by etching where the solder connections are to take place and is left in the remaining areas to act as a solder dam. Certain problems such as etch undercutting and striping have been encountered in removing the top layer of Cr in the desired areas.