Here is the abstract you requested from the SE_2012 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.
|Flux Free Die Attach Utilizing Pressure Variation to Achieve Void Free Results|
|Keywords: Vacuum Soldering, Void Free Attach, Flux Free Environment|
|As microelectronic designers are forced to design semiconductors with higher power and higher efficiencies the need for void free die attach becomes critical. Additionally, the materials and techniques developed to assemble these packages must assure that quality and reliability of the device performance is taken into consideration. For the package to survive and perform flawlessly over the life of the device, the selection of materials and the solder joining method must help control and prevent voiding in reflow soldering. Improved advancements were developed where flux less and void less results were achieved utilizing vacuum and positive gas pressure, known as a pressure variation method, to reduce the final void volume. The principle of the pressure variation method is to use a vacuum to lower the partial pressure of oxygen, which sufficiently prevents oxidation, and to use an external inert gas pressure to compress any trapped voids in the solder joints that are present during the molten stage of the solder reflow. The ability to control the process parameters and to control the soldering environment, without flux, will help establish a void free bond which contributes to the reliability and high performance requirement of higher power semiconductors.|
|Bruce Wilson, Regional Sales Manager