Vishay Make Quad OPTO SFH6916 Failure

[Nishnant Pawar]

Myself Nishnant Pawar from “TRANSASIA Biomedical Ltd—Mumbai (India).”Looking after Quality.
Currently We are facing issue of “Input channel Leakage” with Vishay Make IC “SFH 6916- Quad Opto”. After mounting this IC on PCB this phenomenon of IC input channel becoming leaky is noticed some times during zero hour checking itself in some ICs, and in some cases is also noticed after the assembled PCB is kept on functional test in our machine.
During Incoming Inspection we are measuring the voltage drop across the diode in cold condition to segregate the OK and NOK ICs. Though we are not keen on doing this inspection, we are still doing it because of occurrence of rejections due this IC.
But still we are getting the rejection from field and after analysis we found that problem with leakage across the diode.
1. Can you suggest any other test which we can carry out in-house to catch such borderline IC’s which are getting failed after some time ( In field).
2. Can you please sugget the soldering profile which need to be followed. We are following non-Rohs process(Leaded).
3. We are doing cleaning using mixture of saphonifier and warm DI water by dipping for about 2 min. Is this cleaning is OK or we need to adopt some other process ?

 

[(*steve*)]

When you say leakage across the diode, do you mean leakage across the optocoupler or the LED showing reverse leakage? If the latter, why is there any reverse voltage across this component? LEDs have a low reverse voltage (around 7 volts is typical) and you rarely (intentionally) reverse bias them.

 

[mofy]

If it is contamination on the PCB, Bob Pease recommends using a dishwasher! No joke. Then baking in an oven at 160 degrees. Not sure if it was F or C, and not sure if the boards were populated or blank, but probably blank.