Here is the abstract you requested from the Automotive_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Development of an Aluminum Wirebondable Lead and Cadmium Free Thick Film Gold Conductor for Extreme Applications|
|Keywords: Thick Film, Gold, Conductor|
|Gold thick film pastes are used in hybrid integrated circuits due to their resistance to corrosion and oxidation when exposed to extreme conditions. High quality gold thick film pastes are also readily wire bondable with modern gold and aluminum high speed wire bonding machines. As electronics are being placed closer and closer to the engine in automobiles, the hybrid integrated circuits are being exposed to more severe environmental conditions. At the same time the electronic content of modern automobiles is increasing every year which requires more power and higher current through the hybrid circuits. Increased power throughput requires larger diameter wires, leading to increased cost. Cost is always a driver in automotive electronics so there is a tendency to use Aluminum wires for die interconnection to the gold thick film. Normal testing conditions that are used to simulate under the hood environments include thermal cycling from -40/+150ºC, 85%RH/85ºC, and long term high temperature storage at 150ºC. The new gold thick film materials are tested at more extreme temperatures up to 175ºC and for longer times at temperature, up to 3,000 hrs. The increased test temperatures and time raises the concern of excessive aluminum and gold interdiffusion which is detrimental for long term reliability. This presentation will outline the results of these types of tests using aluminum wire on a new Pb and Cd free gold thick film material which is being developed to handle more extreme environmental conditions.|
|David Malanga, Technical Service and Sales Manager
Heraeus, Thick Film Division
West Conshohocken, PA