Hi,
Unfortunately this happens quite often.
I have also seen this with vertical IC's. LA7838 was a popular one a few years ago.
Your lucky MCM gave you a credit. In most cases they will fight with you, saying that you must not have found the cause of the original failure..blah..blah..blahh...
The problem is pure greed.
If the originals sell for $7 to $12 and you could Counterfit one that may cost you a $1 or 2 and you sold them for $5.95 each and made 500,000 of them, you could stand to make close to 2 million dollars by dumping them on the market to mail order houses etc...
When i receive components, i inspect them looking for the telltale clues. Has the face been sanded, is the ink stamp the same, are the numbers in the correct places, does the ink come off with a contact cleaner(on real ones this won't happen), are there any physical differences between the original and replacement? is it thicker/thinner, 1/16" wider, etc...
I would rather wait a few more days to get replacements in from a different company if i have to, than to watch all my work go up in smoke from installing bargin priced substandard components.
Thanks
joe
Unfortunately this happens quite often.
I have also seen this with vertical IC's. LA7838 was a popular one a few years ago.
Your lucky MCM gave you a credit. In most cases they will fight with you, saying that you must not have found the cause of the original failure..blah..blah..blahh...
The problem is pure greed.
If the originals sell for $7 to $12 and you could Counterfit one that may cost you a $1 or 2 and you sold them for $5.95 each and made 500,000 of them, you could stand to make close to 2 million dollars by dumping them on the market to mail order houses etc...
When i receive components, i inspect them looking for the telltale clues. Has the face been sanded, is the ink stamp the same, are the numbers in the correct places, does the ink come off with a contact cleaner(on real ones this won't happen), are there any physical differences between the original and replacement? is it thicker/thinner, 1/16" wider, etc...
I would rather wait a few more days to get replacements in from a different company if i have to, than to watch all my work go up in smoke from installing bargin priced substandard components.
Thanks
joe
peranders said:
Hey...get rid of the pink glases
MCM and farnell are two and the same (same mother comp) You can be sure that farnell europe is doing the exact same thing as farnell usa or MCM.
I try to buy my components from a distributer listed by the manufactrer (find it on their web page).
Magura
peranders said:
I have received fakes from RS in the UK:
http://www.instantboard.com/users/rode/viewtopic.php?p=2447#2447
It may not be a counterfeit part. It may just be a manufactured replacement part.
To replace a part, it is not necessary to have the same amount of silicon real estate. In fact, if they can do the same function with less real estate, they can make far more per wafer.
The older transistors did not really use the silicon efficiently, as the emitter fingers were really not covering the bulk of the active device, and the junction component that was not directly under the emitter window saw very little current due to lateral resistivity. But, even with reduced conduction losses, there is a loss of transient thermal capability in the 1 to 50 millisecond realm, making the smaller die more susceptible to a fast rising active power pulse to take it out by beta crowding.
Also, the ablility to grade the base-collector junction at the edge better has allowed the reduction of the breakdown control region along the periphery of the die, also reducing the real estate required.
Nowadays, by processing parameters, epi processes, litho improvements, etc., the silicon is used more effectively, allowing the reduction of the die size. (you can thank the IR people with the hexfets for a lot of that stuff).
It's also possible the die breakdown voltage ain't what you are used to..higher, lower, who knows..
And last (yah, I know....whew!!)...heatsinking is hugely affected..the thermal spreading of the smaller die will not use an electrical isolator as well as the larger die..this may require you add a thermal spreader directly under the die before the heatsink...Use some of that copper loaded penetrox stuff to a 1/8 thick copper spreader, do the electrical iso under the copper, that way you use more of the isolation pad thermal cross section..
Cheers, John
PS...maybe it is just a bad lot?? Some manu's will have a ladder of customers they sell to..at the top are customers with high quality standards, at the bottom, are the ones who take the rejects..I don't know where MCM lays..
OH...I forgot..the silicone covering "goop" you see over the die is to protect the die and wirebond connections from the encapsulation epoxy. Some potting compounds will physically damage the die surface or wirebond connections because of tce mismatches, and the temp swings from on/off operation. Some of the higher cost encapsulants do not require the goop, and sometimes the goop is also black.
To replace a part, it is not necessary to have the same amount of silicon real estate. In fact, if they can do the same function with less real estate, they can make far more per wafer.
The older transistors did not really use the silicon efficiently, as the emitter fingers were really not covering the bulk of the active device, and the junction component that was not directly under the emitter window saw very little current due to lateral resistivity. But, even with reduced conduction losses, there is a loss of transient thermal capability in the 1 to 50 millisecond realm, making the smaller die more susceptible to a fast rising active power pulse to take it out by beta crowding.
Also, the ablility to grade the base-collector junction at the edge better has allowed the reduction of the breakdown control region along the periphery of the die, also reducing the real estate required.
Nowadays, by processing parameters, epi processes, litho improvements, etc., the silicon is used more effectively, allowing the reduction of the die size. (you can thank the IR people with the hexfets for a lot of that stuff).
It's also possible the die breakdown voltage ain't what you are used to..higher, lower, who knows..
And last (yah, I know....whew!!)...heatsinking is hugely affected..the thermal spreading of the smaller die will not use an electrical isolator as well as the larger die..this may require you add a thermal spreader directly under the die before the heatsink...Use some of that copper loaded penetrox stuff to a 1/8 thick copper spreader, do the electrical iso under the copper, that way you use more of the isolation pad thermal cross section..
Cheers, John
PS...maybe it is just a bad lot?? Some manu's will have a ladder of customers they sell to..at the top are customers with high quality standards, at the bottom, are the ones who take the rejects..I don't know where MCM lays..
OH...I forgot..the silicone covering "goop" you see over the die is to protect the die and wirebond connections from the encapsulation epoxy. Some potting compounds will physically damage the die surface or wirebond connections because of tce mismatches, and the temp swings from on/off operation. Some of the higher cost encapsulants do not require the goop, and sometimes the goop is also black.
ISO in the US???
ahahahhahahahha
having had first hand experience with ISO 9002 ( I implemented it in a service co) in Brussels I can tell you that here in the US not a lot of co's are eager to be certified.
You see they think it does not give ROI!
Only things that are good for ROI are to be applied. You may argue that applying an ISO way of working is good in the long run and you are most certainly right but 'the long run' is, again, not necessary here, the maximum a co or manufacturer thinks ahead is about 10 months.
A lot happens here in 10 months or less!
The hardest time I have faced getting used to worksystems (from the 7 countries) was the USA ...... unbelievable the way people act and react .........
Jean-Pierre
ahahahhahahahha
having had first hand experience with ISO 9002 ( I implemented it in a service co) in Brussels I can tell you that here in the US not a lot of co's are eager to be certified.
You see they think it does not give ROI!
Only things that are good for ROI are to be applied. You may argue that applying an ISO way of working is good in the long run and you are most certainly right but 'the long run' is, again, not necessary here, the maximum a co or manufacturer thinks ahead is about 10 months.
A lot happens here in 10 months or less!
The hardest time I have faced getting used to worksystems (from the 7 countries) was the USA ...... unbelievable the way people act and react .........
Jean-Pierre
It has nothing to do with ISO9000.....
Or any of the ither rubbish I see here.
MCM is not a franchised distributor for Toshiba. They buy their parts on the open market, and who knows what they get, or where comes from.
As for inefficient use of silicon.......
We are talking about perhaps the most popular set of output transistors ever made. The came about in the late 80s or so. These are not some relic from the 60s that any SK or HEP or NTE or whatever generic garbage replacement part you dredge up form your local TV repair shop people are talking about.
I don't want to have to 'splain this again.
Jocko
Or any of the ither rubbish I see here.
MCM is not a franchised distributor for Toshiba. They buy their parts on the open market, and who knows what they get, or where comes from.
As for inefficient use of silicon.......
We are talking about perhaps the most popular set of output transistors ever made. The came about in the late 80s or so. These are not some relic from the 60s that any SK or HEP or NTE or whatever generic garbage replacement part you dredge up form your local TV repair shop people are talking about.
I don't want to have to 'splain this again.
Jocko
Uvodee wrote: "having had first hand experience with ISO 9002 ( I implemented it in a service co) in Brussels I can tell you that here in the US not a lot of co's are eager to be certified."
The last two places I worked in the US took ISO 9000/9002 very seriously. It may because they rely on export markets. I think you will find this is pretty much the case in most US technology companies.
The last two places I worked in the US took ISO 9000/9002 very seriously. It may because they rely on export markets. I think you will find this is pretty much the case in most US technology companies.
indeed.. You are right when adding
when the US co has to deal with a wide clientele in Europe they will go for ISO certification, otherwise fuggedaboutit!
The person who claims it has nothing to do with ISO is, imho, not really familiar with quality and ISO
An ISO certified manufacturer, distributor and everything related WOULD NEVER have a problem repeat itself!!!!
That is, at least, when they want to keep the certification!
Jean-PIerre
when the US co has to deal with a wide clientele in Europe they will go for ISO certification, otherwise fuggedaboutit!
The person who claims it has nothing to do with ISO is, imho, not really familiar with quality and ISO
An ISO certified manufacturer, distributor and everything related WOULD NEVER have a problem repeat itself!!!!
That is, at least, when they want to keep the certification!
Jean-PIerre
How hard is this to understand?
MCM is not a franchised distrubutor. The sell replacement grade parts to the service industry. They are not ISO certified because the people that they sell to don't give a rat's rear end about ISO.
They fix TVs and VCRs for a living, not the latest Mars lander.
If you want the real part, buy it from the right guy. Normally, MCM has the real deal. But as this part is so popular, and Toshiba is moving on to a better part, it leaves the door open to weasels to make imitations.
Yes, it is not Toshiba's newest fab capabilites, but it took them how long to come up with a better part, hmmmm????? They aren't going to rework existing silicon, when it is a lot easier to DC the existing one and introduce a better version. Which they have done.
Not that any of that matters to the weasels who make imitations.
Jocko
MCM is not a franchised distrubutor. The sell replacement grade parts to the service industry. They are not ISO certified because the people that they sell to don't give a rat's rear end about ISO.
They fix TVs and VCRs for a living, not the latest Mars lander.
If you want the real part, buy it from the right guy. Normally, MCM has the real deal. But as this part is so popular, and Toshiba is moving on to a better part, it leaves the door open to weasels to make imitations.
Yes, it is not Toshiba's newest fab capabilites, but it took them how long to come up with a better part, hmmmm????? They aren't going to rework existing silicon, when it is a lot easier to DC the existing one and introduce a better version. Which they have done.
Not that any of that matters to the weasels who make imitations.
Jocko
uvodee,
I'm not sure where you are comming from, but having served as an ISO9002 auditor, I can tell you that while the certification is nice to have, it should not be over rated. The ISO premise boiled down is that procedures are documented, and once documented are followed. Added to that is are such concepts as 100% tracking and identification of inventory and product.
It is entirely possible (and all too common) to be 100% ISO compliant, yet produce a product with a poor design which is of little use to your customer. The company has, of course, documented the hell out of it. You can even have a horendous field failure rate while being 100% compliant - again ith all the paperwork in order!
I'm not sure where you are comming from, but having served as an ISO9002 auditor, I can tell you that while the certification is nice to have, it should not be over rated. The ISO premise boiled down is that procedures are documented, and once documented are followed. Added to that is are such concepts as 100% tracking and identification of inventory and product.
It is entirely possible (and all too common) to be 100% ISO compliant, yet produce a product with a poor design which is of little use to your customer. The company has, of course, documented the hell out of it. You can even have a horendous field failure rate while being 100% compliant - again ith all the paperwork in order!
that Sir,
should be angels singing in the ears of CEDO's COO's and all other weasels!
as you stated :that procedures are documented, and once documented are followed. Added to that is are such concepts as 100% tracking and identification of inventory and product.
it is the Nec Plus Ultra for all directors all over the world. That at least the work is done in compliance with what was originally intended...
And you statement:yet produce a product with a poor design which is of little use to your customer" is indeed not relative to ISO but at least, when the product appeals to customers , one cna be sure that it is made or supplied uniformly with the necessary QC and back up.
However if ISO standards are truly met (look at the european industry) sales failures could be avoided!
Jean-Pierre
(I have been an ISO 9002 instrumentalist since 1996)
should be angels singing in the ears of CEDO's COO's and all other weasels!
as you stated :that procedures are documented, and once documented are followed. Added to that is are such concepts as 100% tracking and identification of inventory and product.
it is the Nec Plus Ultra for all directors all over the world. That at least the work is done in compliance with what was originally intended...
And you statement:yet produce a product with a poor design which is of little use to your customer" is indeed not relative to ISO but at least, when the product appeals to customers , one cna be sure that it is made or supplied uniformly with the necessary QC and back up.
However if ISO standards are truly met (look at the european industry) sales failures could be avoided!
Jean-Pierre
(I have been an ISO 9002 instrumentalist since 1996)
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