Browse Prior Art Database

Direct Chip Bonding With Bump On Substrate

IP.com Disclosure Number: IPCOM000100308D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Suzuki, H: AUTHOR [+2]

Abstract

Disclosed is a direct chip bonding method with bumps formed on a substrate glass of a liquid crystal display.

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This is the abbreviated version, containing approximately 87% of the total text.

Direct Chip Bonding With Bump On Substrate

       Disclosed is a direct chip bonding method with bumps
formed on a substrate glass of a liquid crystal display.

      Bumps are formed on a glass substrate simultaneously with
liquid crystal display circuit fabrication process. The height of the
bumps is between 3 and 5 micrometers.  By using the same process for
liquid crystal display circuits, height and surface flatness of the
bumps are controlled under sub-micron order.

      Electrical connection between aluminum electrodes of
semiconductor chips and bumps on the glass substrate are made with
conductive particles of 5 to 20 micrometers diameter nickel (Fig. 1).

      Conductive particles are uniformly distributed by mixing with
adhesive (thermo-set, UV-set or thermo-plastic resin). These
conductive particles/adhesives are dispensed between semiconductor
chips and substrate glass, then compressed to achieve electrical
connection.  This system is maintained with adhesive (Figs. 2 and 3).
Multiple small voids (MSVs) occur during controlled collapse chip
connection (C4) chip joining process due presumably to entrapped
organic materials or flux in metalization voids (Cr/Cu/Cr).  Scanning
electron microscope (SEM) analysis on C4 structures has suggested
that the metalization voids on the substrate are responsible for
MSVs.  It was observed that the voids in C4 solder are connected to
the metalization voids of the substrate.  The metalization void is
rel...