Triple track

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... 

Triple-track resistor and conductor coupons are made by deposition of Ta2N and Ti-Pd-Au metallization, respectively, on the AI2O3 substrate. This test pattern consists of three parallel meandering lines with 3-mil spaces between lines. Each line is approximately 3-mil wide and has 2.86 X ]0 squares, with an overall length of 8.5 in. The number of squares of insulator between adjacent lines is approximately 3.5 X 10". ... 

Figure 5. Triple-track resistor electrical testing performance of crown ethers in commercial RTV silicon encapsulants. Conditions bias, 180 V relative humidity, 96% temperature, 100°C.

Modeling of Triple-Track and Comb-Pattern Leakage Current Measurements... 

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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