Here is the abstract you requested from the Wirebond_2009 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.
|The Stressful World of RF Ribbon Bonding|
|Keywords: Ribbon Bonding, Ribbon Bond Fatigue, Ribbon Bond Testing|
|Ribbon bonding is used as the primary interconnect method in the manufacturing of RF MCMs, connecting an array of active/passive devices to substrates/packages using low loop, short span ribbons. Since the demands of the design to achieve maximum RF performance drive the components to have small bond pads and limits the ability to have redundant interconnects, a single ribbon bond interconnect can be a source for a “single point of failure.” Non-destruct testing of ribbons is ineffective in detecting CTE impacts which are cumulative as the product is manufactured, tested and operated in the field. Established workmanship standards (MIL-STD-883, method 2017) for high reliability modules do not adequately address ribbon bonds using today’s equipment and tools. Visual inspection is not sufficient; identification and understanding of the physical process indicators exhibited by ribbons is key to failure detection. Designing and validating ribbon configuration based on the CTE of the interconnect surface base material and housing as compared to the environmental extremes of the RF MCM to meet end of life strength conditions is a critical phase in the development of the product. Unfortunately, conventional FEA modeling has shown not to be an effective tool in understanding the absolute strains in ribbon bonds, particularly when deformed into the plastic region. Non-linear deformation also causes the Coffin-Manson method for predicting lifespan from an accelerated thermal cycle test results to breakdown. . With limited time from Development to Manufacturing phase to perform accelerate life testing using thermal cycling methods, a different approach must be derived to simulate the CTE displacements, but still provide results to be implemented in the Manufacturing phase. As a results of testing, it was determined that control and verification of loop heights and spans is just as important as maintaining spacing between components for High Reliability RF Modules. NON-Export-Contolled Information`|
|Joseph Kreuzpaintner, Technologist