Bad diodes 1

BSE SEM image of stock diode sample.

Bad diodes 2

A crack is present in the glass body.

There were fractures in the glass case near the terminations on all of the stock diodes examined. There is significant risk that these fractures would propagate to failure due to expected assembly and use stresses.

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The device exhibited a metallic short between pin-5 and an internal circuit element (a resistor that would normally be isolated). The short appeared to be solder material (primarily tin) from the pin-5 termination that flowed into the device due to excessive temperature exposure during assembly.

Solid State Relay 1

Fig. A – Solid-State Relay

Solid State Relay 2

Fig. B – Decapsulated, bottom side

Solid State Relay 3

Fig. C – Metallic short between pin-5 and an internal circuit

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