Dismiss
The InnovationQ application will be updated on Sunday, May 31st from 10am-noon ET. You may experience brief service interruptions during that time.
Browse Prior Art Database

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

Publishing Venue

IBM

Related People

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

Abstract

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.