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Old 7th Apr 2019, 3:14 pm   #17
Craig Sawyers
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Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,982
Default Re: Chinese power transistors

Thinking of fakes, about 9 months ago I bought 7 pairs of 2SC3264/2SA1295 power transistors on eBay. Before I soldered them in for a recent project, just to be sure I measured the size of the package using a micrometer, and it was outside the maximum tolerance for the Sanken MT200 package.

Now suspicious, I put one on the curve tracer (Tek 576) and compared it to a genuine part. It beta saturated at half the current of the genuine part, and had a Vceo of 125V as compared with 260V for a genuine Sanken part (spec 230V).

Weight was 14 grams as compared with 18.

So I used a hammer to expose the die.

The fake part had a die which was bonded directly to the heatsink plate, that was 2mm square.

The genuine part has an additional metal tab that doubles the thickness of metal under the 6mm square die. Hence the higher weight in the genuine part. The genuine Sanken part has a die with 9x the area of the fake.

I've contacted the seller (agiia) via eBay, twice, with evidence. He is not responding, but is still selling the fake power transistors.

Craig
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