Gold‐Tin Solder Bumps for TAB Inner Lead Bonding with Reduced Bonding Pressure
- 1 March 1992
- journal article
- review article
- Published by Emerald Publishing in Soldering & Surface Mount Technology
- Vol. 4 (3) , 27-32
- https://doi.org/10.1108/eb037800
Abstract
Tape automated bonding (TAB) is a suitable technology for assembling ICs with a high number of l/Os. The gang bonding process usually applied requires increasing thermode forces for chips with high lead counts and narrow tolerances regarding thermode parallelism and planarity. Due to the high bonding pressure, TC bonding of Au bumps to Au‐plated tapes becomes critical for these applications. In order to avoid damage to the pad structure an inner lead bonding (ILB) process with reduced pressure is required. A tape metallisation of 0.5–1.0 µm Sn is not sufficient for a significant reduction of thermode pressure. As an alternative, the application of an eutectic Au‐Sn cushion which is deposited on top of the bumps is presented. A modified bumping process was developed for the deposition of the solder bumps. Soldering of the Au‐Sn bumps to a Au‐plated tape was performed successfully by two techniques: thermode gang bonding and laser soldering. Bond parameters and tin layer thickness were optimised. Reliability investigations by thermal ageing were performed. The special metallurgical aspects of the system were investigated with a microprobe.Keywords
This publication has 9 references indexed in Scilit:
- Hardness reduction of Au bumps for tab interconnectionsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- Reliability of thermally aged Au and Sn plated copper leads for TAB inner lead bondingPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Investigations of laser soldered TAB inner lead contactsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Extremely reliable bonding of large silicon dice using gold-tin alloyPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- A laser based system for tape automated bonding to integrated circuitsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Development of a Fine Pitch Bumping ProcessPublished by Springer Nature ,1990
- The Application of an Eutectic Gold-Tin Cushion for TAB-Inner Lead Bonding with Reduced Bonding PressurePublished by Springer Nature ,1990
- Investigations of failure mechanisms of TAB-bonded chips during thermal agingIEEE Transactions on Components, Hybrids, and Manufacturing Technology, 1990
- Bond Strengths of Inner and Outer Leads on TAB DevicesMicroelectronics International, 1986