Here is the abstract you requested from the MASH_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.
|Cumulative Helium Leak Detection (CHLD), Frist New Test Method for Testing Hermetic Packages in over 30 Years, Case Studies of Previously Manufactured Parts that Failed after Years on Shelf|
|Keywords: Cumulative Helium Leak Detection , Hermiticity , Re-testing|
|Cumulative Helium Leak Detection, now a published mil standard (Mil Std 750 Method 1071 CH1 & CH2), represents the first new method approved for testing hermetic parts in over 30 years. CHLD combines fine and gross leak into a single operation with a contiguous range from 1 atm-cc/sec through 10-13 atm-cc/sec, eliminating the use of Fluorocarbons. In the past year three different clients have attempted to use previously manufactured and certified parts in mission critical applications only to find, upon re-screening, that some of the parts now had high moisture content. Using the higher sensitivity of the CHLD method, the Pernicka Corporation was able to identify parts that passed the 5000 PPM moisture limit, sufficient to allow the programs to proceed. In the process, data was collected that has been presented to JDEC that suggests that a review of the current Pass/Fail limits for hermetic parts is needed. The presentation includes a summary of the CHLD system and its operation and a discussion of test results that using the CHLD method identified hermetic integrity issues of parts that in one case had been on a shelf for over 10 years. The data suggests that the failed parts, all of which passed the current hermitic test limits, had moisture ingress from their date of manufacture to the time of testing done years later. The CHLD test method was developed by the Pernicka Corp. and is presently installed at leading manufacturers of high reliability components.|
|John Pernicka , CEO
Fort Collins, CO