Browse Prior Art Database

Chip/Carrier Bumping Using Laser Enhanced CVD

IP.com Disclosure Number: IPCOM000103015D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 41K

Publishing Venue

IBM

Related People

Baum, T: AUTHOR [+8]

Abstract

Metal bumping of chips or carriers requires selective deposition of metal in specified areas. Bump shapes are required to be Gaussian, flat top or volcanic in geometry.

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Chip/Carrier Bumping Using Laser Enhanced CVD

      Metal bumping of chips or carriers requires selective
deposition of metal in specified areas.  Bump shapes are required to
be Gaussian, flat top or volcanic in geometry.

      The technique disclosed herein makes use of a relatively new
technology, photothermal chemistry, where a volatile organometallic
compound is thermally or photolytically decomposed to produce the
metal on a surface selectively.

      This technique produces a rapidly built-up structure on either
a wafer via area or on the surface of a circuit finger similar to a
bump or small vertical protrusion.  Such bumps are made of gold or
other metals in which thermocompression bonding is used to produce
completed packaged structures.

      Cones of metal having Gaussian or flat top geometries or
volcanic types of structures can be produced using these
technologies.  The shapes can be controlled by the use of buffer
gases and pressures which dictate the rates of deposition and the
decomposition phenomena.

      This technique has the advantages of being programmable using
an X/Y table and the flexibility of use on both chips and carriers
with equal ease.  It is inexpensive and uses gaseous vapors of
organometallic materials to provide a source of the metal.  The bump
shape is controllable and provides maximum coverage and can be
produced on all semiconductor and packaging materials.

      Disclosed anonymously.