Scribe, break and dig method for glass axial lead and surface mount type diodes.
The aim of this test is to inspect the die inside glass axial lead and surface mount type diodes.
The testing is performed in accordance with MIL-STD-750, method 2101, and consists in deliberately destroying the device to allow visibility to the die attachment area. To achieve this, the diode body is scored circumferentially at the location of the die plane (usually using a diamond-tipped scribe) and then snapped into two pieces.
Alternatively, the glass body may be chemically dissolved so that the die attachment area becomes visible. It is of great importance to proceed with utmost care so that the die and die metallization are not attacked by the chemical.
The two plug surfaces resulting from snapping are inspected for both silicon and die metallization residue. The silicon remaining on each plug may be chemically removed to provide visibility to the attachment interface materials or by further scraping or digging through all of the bond interfaces; however, this step is not mandatory. Photographs of both separated attachment surfaces are taken.