Test company puts ScanWorks to the test
 Before a test company deploys a test technology, chances are pretty good that the new test technology is going to be examined rather thoroughly. That was precisely the case when Aeroflex Inc. was considering an implementation of JTAG and, specifically, ASSET’s ScanWorks® system for design debug and manufacturing test.
“The fact that most of our circuit boards have chips in ball grid array (BGA) packages was driving us toward boundary scan,” said Will Dobbin, test specialist at Aeroflex. “Our boards average at least four BGAs each and we have some with as many as eight BGAs. And some of these devices have as many as 1,500 solder balls under them. We have to be able to test them.”
Aeroflex, which manufactures high-performance test platforms for communications, aerospace, military and avionics systems, had been testing boards with it’s own Aeroflex 4200 Series in-circuit test (ICT) systems as well as Aeroflex 5200 Power Manufacturing Defect Analyzers (MDA). Adding JTAG testing to Aeroflex’s existing line of ATE equipment within the manufacturing plant increased test coverage and significantly improved the company’s diagnostic capabilities. In addition, even though Dobbin and Mark Elzinga were rather new to boundary scan, they were able to develop three working JTAG tests within three weeks.
“We were thrilled that we could write and debug our first three tests within three weeks,” Dobbin said. “And we were getting good test coverage in the range of 30 to 60 percent. We were very pleased that we were up and running so quickly.”
ScanWorks has been deployed on Aeroflex’s manufacturing line, but it is has also been implemented by the company’s design department to debug prototypes. ScanWorks’ diagnostics capabilities have made believers out of the company’s designers.
 “On one prototype test run, the design engineer, knowing that he had faults, asked us to test his design. He didn’t know where the faults were physically,” Dobbins explained. “We were able to push a button on ScanWorks and tell him exactly where the faults were. We gained a lot of credibility with the design engineer when we were able to do that. Fifteen other prototype assemblies had BGAs replaced and we were able to test and verify this rework.”
“I am working on a boundary scan design-for-test (DFT) document for the design engineers so we can get the most out of this technology. The acceptance on the part of the designers has been very good. We are very fortunate in that regard.” |
