Triple track testing device

Electrical Properties. Electrical properties are important for the corrosion protection of chip-on-board (COB) encapsulated devices. Accelerated temperature, humidity, and bias (THB) are usually used to test the embedding materials. Conventional accelerating testing is done at 85°C, 85% relative humidity, and d-c bias voltage. Triple-track test devices with tantalum nitride (Ta2N), titanium—palladium—gold (Ti—Pd—Au) metallizations with 76... 

Figure 6 Schematic diagtam (left) and an SEM photograph (right) of two triple-track test structures that are used to study electrolytic corrosion mechanisms along with the effectiveness of passivation layers. The stmcture shown on the right was encapsulated and then exposed to HAST conditions until lailure. This particular structure is part of the integrated test device shown previously in Figure 5. These test devices contain eight triple-track sections (the left set with windows in the passivation layer) and exposed wirebond pads.

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