Aerospace Scientists Use X-ray to Avert Costly Milstar Rework

EL SEGUNDO, Calif. (10/26/98) -- Scientists at The Aerospace Corporation used an X-ray microscope to scan seven suspect boxes containing flight digital processor boards for a Milstar payload, saving the Milstar program several months of rework and requalification.

Dr. Gary Stupian and Dr. Martin Leung of the Microelectronics Technology Department, working with Tom Hoskinson and Dan Gutierrez of the Military Satellite Communications Division, used the Feinfocus X-ray system--one of many analytical instruments used in the Electronics Technology Center to investigate customer problems--to check resistor and diode clearances.

Insignificant attention had been paid to the spacing between the aluminum mounting ribs in the flight lids and the diodes and resistors mounted on the boards adjacent to the lids.

Normal manufacturing variances had in some cases resulted in damage to components mounted too near aluminum support ribs. The problem was not discovered until the boxes were assembled and qualification was completed.

Opening each box to inspect for damage would have entailed additional rework and requalification for each box, adding expense and time to the integration process.

The X-ray process demonstrated that six boxes had enough clearance to avoid damage and ensure reliable operation. The seventh box was taken apart and reworked when the X-ray images showed questionable spacing between a component and the aluminum box.