DocumentCode :
2513024
Title :
Inner lead bonding for a resin molded chip size package
Author :
Nagasawa, Megumu ; Tanagawa, Satoshi ; Yoshio, Nobuhiko ; Igarashi, Kazumasa ; Yada, Hiroshi
Author_Institution :
Nitto Denko Corp., Mie, Japan
fYear :
1996
fDate :
14-16 Oct 1996
Firstpage :
386
Lastpage :
392
Abstract :
The present study investigated methods for bonding between semiconductor bonding pads and the metal bumps of a film carrier developed for use in chip-size packages (CSP). The structure of the film carrier is that of a copper circuit bearing a layer of insulating polyimide (PI) on both sides and connecting on one side with the exposed bumps, which in turn connect with the bonding pads. The bumps either have a copper core with a gold surface, or are all gold. In the first stage of the experiment, in which basic data were gathered, the ability of the bumps to bond via gang-bonding with the aluminum of the silicon chip was tested, using bumps with gold-plating of different thicknesses to give exposed heights of 10, 30 and 50 μm. Bump height is a decisive factor in the peeling strength of the bonding site; satisfactory results were not achieved with low bumps of 10 μm height. In the second stage, a method was sought which would help minimize production cost by ensuring successful bonding even with bumps of only 10 μm height. The three following methods were tested and found effective: (1) inserting a convex frame immediately beneath the film carrier on the side opposite the bumps; (2) using a film carrier containing a layer of thermoplastic material immediately beneath the bumps; and (3) undertaking scrubbing during the initial bonding phase
Keywords :
adhesion; copper; deformation; gold; integrated circuit packaging; lead bonding; surface treatment; 10 to 50 micron; Al; Al-Au; Au; Au plating; Cu; Cu circuit; Cu-Au; ILB; bump height; convex frame; film carrier; gang-bonding; inner lead bonding; insulating polyimide layer; metal bumps; peeling strength; production cost minimisation; resin molded chip size package; scrubbing; semiconductor bonding pads; thermoplastic material; Bonding; Chip scale packaging; Circuits; Copper; Gold; Insulation; Polyimides; Resins; Semiconductor device packaging; Semiconductor films;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electronics Manufacturing Technology Symposium, 1996., Nineteenth IEEE/CPMT
Conference_Location :
Austin, TX
ISSN :
1089-8190
Print_ISBN :
0-7803-3642-9
Type :
conf
DOI :
10.1109/IEMT.1996.559770
Filename :
559770
Link To Document :
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