Military Screening and Qualification Procedures

Tekmos has had an increase in ASIC products required for military applications. Because of this we have had to incorporate military screening and qualification procedures.

Tekmos follows military screening outlined in Mil-STD-883: Test Method 5004.13. This screening consists of tests dedicated to inspect the design, wafer fabrication, and device assembly of a product and is performed on the entire Lot of parts. The tests include Nondestructive Bond Pulls, Temperature Cycling, Electrical Parameter Tests, and more. So far Tekmos has had a 100% success rate on military screening 5004.13.

Unlike the initial screen procedures, the military qualification procedures are outlined in Mil-STD-883: Test Method 5005.17 and only use a small portion of the Lot for testing. Many of the tests are considered destructive, which ultimately means the parts no longer are active for customer use and must be scrapped. Qualification involves 5 groups of testing; Group A: Electrical, Group B: Mechanical and Environmental, Group C: Life Tests, Group D: Package, Group E: RHA (if applicable).

Group A testing is done in-house once production parts arrive from the dedicated assembler. Tekmos begins screening by performing an initial electrical test to remove any assembly rejects from the Lot. After Initial test, parts are then placed in ovens for a burn-in cycle in accordance with TM 1015, for 160 hours at 125ºC. While the parts are under burn-in, Tekmos constantly monitors the current output of the parts to ensure their electrical stability. Once completed, the parts will run through a tri-temperature screening with the same initial test used pre-burn-in. The parts are tested at 125ºC, 25ºC, and -55ºC to make certain the product is meeting the device specifications.

For Groups B and D, Tekmos sends off parts to an approved test house. These parts, although tested off-site, are constantly being tracked through various communication channels for accurate completion estimates and potential issues needing to be resolved. Once all parts have completed, the test house will send reports and certificates of conformance for the testing performed. The reports are then reviewed by the Production Engineer, Zachary Kolb, and Director of Quality, Kelsey Casto.

While Groups B and D are being tested off-site, Tekmos begins the final and longest Group testing in the military qualification, Group C. This testing is in accordance with TM1005, the steady state Life Test. This test is used to demonstrate the reliability of parts under specific conditions over an extended period of time using an oven chamber. The typical conditions used by Tekmos for this Life Test burn-in are; a 125ºC oven, 1000-hour duration, and a sample size of 45 parts. After the 1000 hours, the parts undergo an end-point electrical screening to confirm the parts are still operational post-burn-in.

Finally, when all testing has been completed the information is collected and compiled together into one report that is sent to the customer. Along with the data, Tekmos provides a First Article Inspection Report using the AS9102 FAI Report Template. Within this report we verify and evaluate all of the tests done and affirm their accountability with sign offs by Zachary Kolb and Kelsey Casto.