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Perforated Emitter technology

J

John Popelish

Jan 1, 1970
0
I recently came across the data sheet for the MJL21193/4
series of transistors for linear amplifier applications,
http://www.onsemi.com/pub/Collateral/MJL21193-D.PDF
and see that they describe them as being made with
"Perforated Emitter technology". But I am having trouble
finding out exactly what that means.

What is it, and where can I find the details? Thanks.
 
E

Eeyore

Jan 1, 1970
0
John said:
I recently came across the data sheet for the MJL21193/4
series of transistors for linear amplifier applications,
http://www.onsemi.com/pub/Collateral/MJL21193-D.PDF
and see that they describe them as being made with
"Perforated Emitter technology". But I am having trouble
finding out exactly what that means.

What is it, and where can I find the details? Thanks.

It's a multi-emitter technology AIUI, designed to reduce secondary breakdown
effects.

Graham
 
P

Phil Allison

Jan 1, 1970
0
John Popelish said:
I recently came across the data sheet for the MJL21193/4 series of
transistors for linear amplifier applications,
http://www.onsemi.com/pub/Collateral/MJL21193-D.PDF
and see that they describe them as being made with "Perforated Emitter
technology". But I am having trouble finding out exactly what that means.

What is it, and where can I find the details?


** The very first hit on Google is:

http://sound.westhost.com/soa.htm#3.0

Which not only describes the technique and it purpose ( enhanced gain
linearity) - but also has close up pics of the MJL21193 chip itself -
see figs 4.1, 2, 3.

A tiny bit more digging reveals that Toshiba originated the technique and
passed it on to ON.



........ Phil
 
P

Phil Allison

Jan 1, 1970
0
"John Popelish"
I recently came across the data sheet for the MJL21193/4 series of
transistors for linear amplifier applications,
http://www.onsemi.com/pub/Collateral/MJL21193-D.PDF
and see that they describe them as being made with "Perforated Emitter
technology". But I am having trouble finding out exactly what that means.

What is it, and where can I find the details? Thanks.


** Some more digging produced a couple of app notes that mention the term "
perforated emitter " and a nice pic of a device chip showing the actual "
perforations " !!!

Various benefits are claimed for having them, including very low Vce sat.

http://www.onsemi.com/pub/Collateral/AN1080-D.PDF

http://www.onsemi.com/pub/Collateral/LOW VCESAT WHITE PAPER.DOC


Seems that it is a " state of the art " design technique for BJTs, so
makers are still a bit coy about giving away secrets.



....... Phil
 
J

Jamie

Jan 1, 1970
0
Phil said:
** The very first hit on Google is:

http://sound.westhost.com/soa.htm#3.0

Which not only describes the technique and it purpose ( enhanced gain
linearity) - but also has close up pics of the MJL21193 chip itself -
see figs 4.1, 2, 3.

A tiny bit more digging reveals that Toshiba originated the technique and
passed it on to ON.



....... Phil
We've use those before. I thought i've seen that number some where.
now to think about it. We made a DC servo amp with them. It could
of been made with others of course.

I think the reason we tried those were due to the gain curve and
voltage handling.
 
E

Eeyore

Jan 1, 1970
0
Jamie said:
I think the reason we tried those were due to .......
voltage handling.

Safe operational area (SOA).

Graham
 
J

John Popelish

Jan 1, 1970
0
Phil said:
** The very first hit on Google is:

http://sound.westhost.com/soa.htm#3.0

Which is the first thing I found and found to be pretty brief.
Which not only describes the technique and it purpose ( enhanced gain
linearity) - but also has close up pics of the MJL21193 chip itself -
see figs 4.1, 2, 3.

The test directly above those pictures is "This is also a
good example of the "interdigitised finger" type of emitter
and base construction referred to above." I don't think
these are pictures of MJL21193/4 type devices. Those are
the pictures I have been searching for.
A tiny bit more digging reveals that Toshiba originated the technique and
passed it on to ON.

Thanks.
 
J

John Popelish

Jan 1, 1970
0
Phil said:
** Some more digging produced a couple of app notes that mention the term "
perforated emitter " and a nice pic of a device chip showing the actual "
perforations " !!!

Various benefits are claimed for having them, including very low Vce sat.

http://www.onsemi.com/pub/Collateral/AN1080-D.PDF

Lots of bragging, not many process or mask details.

Finally, a picture. Thanks. It looks like there is a
second layer of metalization over the die for the base with
feedthroughs to the base fingers, to keep the base finger
drop to a minimum.
Seems that it is a " state of the art " design technique for BJTs, so
makers are still a bit coy about giving away secrets.

That might well explain the lack of cross sections, doping
profiles and other details in public view. I am wondering
if Zetex uses this technique for their low saturation, high
gain, high current transistors. They don't seem to be
bragging about it, but perhaps "Perforated Emitter" is
trademarked.

Thanks for the assistance.
 
P

Phil Allison

Jan 1, 1970
0
"John Popelish"
The test directly above those pictures is "This is also a good example of
the "interdigitised finger" type of emitter and base construction referred
to above." I don't think these are pictures of MJL21193/4 type devices.
Those are the pictures I have been searching for.


** They most definitely ARE pics of a MJL21193/43 chip.

Rod Elliot is simply mistaken - I will inform him shortly.

See ABSE now for pics of one from my collection.




....... Phil
 
J

John Popelish

Jan 1, 1970
0
Phil said:
"John Popelish"


** They most definitely ARE pics of a MJL21193/43 chip.

Rod Elliot is simply mistaken - I will inform him shortly.

See ABSE now for pics of one from my collection.

Will do. Thanks.
 
T

The Phantom

Jan 1, 1970
0
I recently came across the data sheet for the MJL21193/4
series of transistors for linear amplifier applications,
http://www.onsemi.com/pub/Collateral/MJL21193-D.PDF
and see that they describe them as being made with
"Perforated Emitter technology". But I am having trouble
finding out exactly what that means.

What is it, and where can I find the details? Thanks.

Remember the RCA "overlay" RF transistors? The 2N3866 is one such.

This patent:

http://xrint.com/patents/us/3602780

mentions the "overlay" structure, as well as the "perforated" emitter
structure.
 
J

John Popelish

Jan 1, 1970
0
The said:
Remember the RCA "overlay" RF transistors? The 2N3866 is one such.

This patent:

http://xrint.com/patents/us/3602780

mentions the "overlay" structure, as well as the "perforated" emitter
structure.

I remember seeing the phrase "overlay RF transistor" but
never knew exactly what it referred to.

Here is an interesting article that evaluates many different
semiconductor structures as high conductivity per area, high
voltage, fast switches and proposes an advancement to the
best case (surprise, its the bipolar junction transistor).
Figure 13 shows the proposed enhancement, that looks like
the ultimate in perforated emitter technology, but I don't
know if anyone makes transistors this way, yet.

http://www.power-tech.com/cartext.htm
 
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