Here is the abstract you requested from the HITEC_2016 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.
|Decapsulation of Copper Wire Bond Devices Using Three-Step Process|
|Keywords: Copper Wire Bond, Decapsulation, Acid Mixture|
|A novel method for copper wire bond decapsulation was developed, which involves conducting a sequential process to ensure minimal corrosion or (in some cases) no corrosion/degradation of the copper wire. It requires a pre-treatment which involves mechanical milling and acid etching, the main decapsulation process utilizing a mixture of nitric and sulfuric acid under electrically biased conditions, and a post decapsulation procedure of encapsulant debris removal using solvent. Previous studies show decapsulation methods that either reveal the ball bond or wedge bond separately, which cannot be used to perform wire pull tests. Exposing both the ball and wedge bond is not trivial, as the wire tends to break at the loop due to long time of exposure. The three-step process, when properly executed, ensures that the entire wire, ball and wedge bond is exposed with minimal damage. Five parameters were found to affect the decapsulation process namely; acid ratio, biasing voltage, time of exposure, temperature and mold compound type, which were refined to result in very less or no copper wire degradation.|
University of Maryland
College Park, Maryland