[Amps] Semtech diode

[Roger (K8RI)]

Radio WC6W wrote:
> Hi John,
>   An individual diode, or other semiconductor device, when it is sawn free from the wafer but, unpackaged.
>   

I thought that was a "Die" or do they just refer to the CPU chip as a die.
Back when they were making those diodes the largest Silicon wafer was 
maybe a couple of inches across.  About 35 years ago they were in the 
neighborhood of 1".  Now they are over 14" in diameter per single 
crystal wafer.
Man! What an improvement in yield and decrease in devise cost.

Early "poly" rods were about 3/4" X 16", then they went to 3 and 4 X 
50". Now days it takes a chain hoist to lift a rod out of the reactor 
and I cant tell you the diameter. Poly is now more pure than the best 
single crystal we had in those days and sells for a few dollars a Kilo.  
Just think, we used to get $165 a gram for intrinsically pure Silicon.

The place I started working was an old cement block garage next to a 
farm house used for the office. They now cover nearly a half square mile 
and are starting a one Billion dollar expansion. Before the last several 
expansions they were the world's largest producer of Poly.
(Poly = poly crystalline Silicon)

BTW, I've used SCRs that had a 1.5" diameter slice of Silicon inside. 
They were water cooled and a pair ran almost unbelievable power.


73

Roger (K8RI and ex Silicon junkie)
> 73 & Good evening,
>    Marv WC6W
>
>
> --- On Mon, 10/27/08, John/K4WJ <k4wjfoc1749 at wildblue.net> wrote:
>
>   
>> From: John/K4WJ <k4wjfoc1749 at wildblue.net>
>> Subject: Re: [Amps] Semtech diode
>> To: "Steve Katz" <stevek at jmr.com>, sccook1 at cox.net, amps at contesting.com, john.brewer at us.schneider-electric.com
>> Date: Monday, October 27, 2008, 6:25 PM
>> At 03:45 PM 10/27/2008, Steve Katz wrote:
>>
>> What is a "dice">
>>
>> de John/K4WJ
>>
>>
>>     
>>> The P/N is a mere coincidence.  Semtech issued all SA
>>>       
>> numbers 
>>     
>>> sequentially, beginning with SA-0001 and going into the
>>>       
>> several thousands.
>>     
>>> A string of 1N5408s, if they are very good ones
>>>       
>> (metalurgically 
>>     
>>> bonded with large dice), should work.   Semtech used
>>>       
>> .125" diameter 
>>     
>>> round dice for this family, they have more silicon in
>>>       
>> them than 
>>     
>>> conventional 1N54xx, and the Semtech parts were all
>>>       
>> dual-plug 
>>     
>>> metalurgically bonded capable of withstanding very high
>>>       
>> surges.
>>     
>>> -WB2WIK/6
>>>       
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>
>
>       
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