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Bought some cheap 30N60's, genuine or fake?

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Dr. Dark Current

Mon Jan 23 2012, 07:09PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

I bought a lot of HGTG30N60A4D IGBTs from one ebay seller. The parts do not look very genuine to me. The package is different from other Fairchild products and the leads seem kind of thin. I had a communication with a friend, who identified a diode manufactured by HOLTEK in almost identical looking package. The packages have the text "MALAY" written with verry small embossed letters in the small circle on the bottom of the package, which I assume means Malaysia.

What do you think?

Pics

Sulaiman

Mon Jan 23 2012, 07:29PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

Test one !
e.g. 12V car (automobile) battery +V to 0R33 resistor (15m of 1mm2 wire) to Collector
Battery -V to Emitter
Gate to Battery +V via 100 Ohm resistor.
(a diode from Collector to +V would clamp any inductive 'flyback' when the transistor is turned off)
Measure Vce(on) to see how well the transistor turns on with Vge = 12V
(should be about 1.7V from the datasheet, 50W continuous = needs heatsink)
................................................. ..........
If it survives that then replace the 0R33 with an inductor
(or wind the wire above around something to form a coil/inductor)
Briefly turn on the igbt and 'scope the Collector waveform to see at what Vce the transistor breaks down due to the 'flyback' voltage from the coil/inductor

P.S. don't forget to video it for our amusement !

Experimentonomen

Mon Jan 23 2012, 07:30PM

Registered Member #941 Joined: Sun Aug 05 2007, 10:09AM
Location: in a swedish junk pile
Posts: 497

Cheaper than street price and from china = fake

I bought a set of IRFP240 and IRFP9240 from ebay for an amp project, the amp played music for several hours straight and then died for no reason what so ever, why ? Because the fets were more than likely counterfeit chinafakes, but i more or less expected this.

Dr. Dark Current

Mon Jan 23 2012, 07:38PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

Yeah I was going to do a forward voltage test on one. Just thought that the not-so-common high performance parts didn't get faked as often as eg. a 2n3055.

Wolfram

Mon Jan 23 2012, 08:40PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

I have heard lots of speculation of fake switching FETs and IGBTs, but I haven't yet seen a confirmed report on one. Killing MOSFETs is not uncommon here, and it's often blamed on fake parts without any further evidence. I would not rule out it being a genuine part just yet.

Genuine Fairchild IGBTs can often look different from each other, I suppose they have more than one production line.

This is a picture I just took of two Fairchild HGTG20N60A4Ds. Both are genuine, one was acquired from a Fairchild sample representative and the other one was bought from Digi-key. Sane exact part, yet they look very different.

I did hear a story of a British coiler who bough a load of IGBTs that turned out to have a manufacturing defect that resulted in the gate breaking down with just +-12V of gate drive applied though, so it's not completely impossible that they are unusable, but I would definitely do some testing before claiming that they are fakes.

If they turn out to not meet datasheet specs, I would be very interested in seeing a dissection of one.

Edit: The one on the right side in my picture also has "MALAY" written inside the small circle on the bottom. The right one has "H6" written inside the circle.

Dr. Dark Current

Mon Jan 23 2012, 08:58PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

Wolfram, my IGBTs look very similar to the right one on your photo.

I just did a test on one. Applied a fair amount of heat paste and mounted it on a big heatsink at ambient temperature. While passing 15 amps, it drops 1.88 volts. The top part of the package gets a bit warm after a few seconds, I don't know if that's good... Anyway the drop is around 0.1-0.2 V higher than the value I got from the datasheet for Tj=25 Â°C.

Wolfram

Mon Jan 23 2012, 09:48PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

If I'm reading the datasheet right, the Vce_sat curve is a typical rating, not an absolute maximum rating. There is no data for Vce_sat max at 15A, but there is for 30A, where it's 2.6V compared to the typical value of 1.8V from the same table. I don't think it's unreasonable to assume that the worst case Vce_sat at 15A is correspondingly higher too. This puts your measurement well within datasheet specs.

Proud Mary

Mon Jan 23 2012, 10:39PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Experimentonomen wrote ...

Cheaper than street price and from china = fake

I bought a set of IRFP240 and IRFP9240 from ebay for an amp project, the amp played music for several hours straight and then died for no reason what so ever, why ? Because the fets were more than likely counterfeit chinafakes, but i more or less expected this.

You should raise the issue with Fairchild China where much of Fairchild's manufacturing now takes place.

Steve Conner

Mon Jan 23 2012, 10:42PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

I heard from someone who bought some HGTG30N60s on EBay and they turned out to be a different IGBT with a smaller die, relabelled.

The little "Malay" circles were different depths on each device, implying a clumsy grinding/sanding job to remove the old markings.

Marko

Mon Jan 23 2012, 10:50PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Dr. Dark Current wrote ...

I bought a lot of HGTG30N60A4D IGBTs from one ebay seller. The parts do not look very genuine to me. The package is different from other Fairchild products and the leads seem kind of thin. I had a communication with a friend, who identified a diode manufactured by HOLTEK in almost identical looking package. The packages have the text "MALAY" written with verry small embossed letters in the small circle on the bottom of the package, which I assume means Malaysia.

What do you think?

They are fake, you bought them for a hong kong seller on ebay ("utsource" or "polida"?)

The sanding job on the igbt's looks very crude. The typical mark of fake parts is that some or all of those three circular pits on the package (the bottom one of which has a tiny "MALAY" inscription on it) tend to dissapear randomly, which I can already see on one of your packages.

Also, the characteristic smooth fillet around the central hole is missing on the fake packages.

Of course, apart from measuring the most effective way to verify is to hammer the igbt's apart and compare the die sizes with known genuine ones. The leg dimensions will also tend to be different from spec.

I got a full refund on this batch of igbt's after sending the seller this pic.

Marko

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