Maker Pro
Maker Pro

Use for "ceramic dual flatpack"?

M

Michael

Jan 1, 1970
0
Greetings dwellers of SED: I was recently going through a datasheet
and came across an oddity of a package. It's called a "ceramic dual
flatpack" (page 11: http://focus.ti.com/lit/ds/symlink/sn74ahct541.pdf).
It does not appear to be surface mountable, as the leads would have to
be bent down to touch the PCB. It is not through hole mountable, as
the leads go straight out.

Can anybody tell me what this package type is used for?

Thanks,

-Michael
 
Greetings dwellers of SED: I was recently going through a datasheet
and came across an oddity of a package. It's called a "ceramic dual
flatpack" (page 11:http://focus.ti.com/lit/ds/symlink/sn74ahct541.pdf).
It does not appear to be surface mountable, as the leads would have to
be bent down to touch the PCB. It is not through hole mountable, as
the leads go straight out.

Can anybody tell me what this package type is used for?

Thanks,

-Michael

This is a military-grade package going back to the 60s. You used a
special die in a press to form the leads and then you weld, yes, weld,
the leads to the PCB. Early digital computers in missiles were built
out packages like these.

http://www.tpub.com/content/neets/14186/css/14186_122.htm

http://homepages.nildram.co.uk/~wylie/ICs/monolith.htm

http://ed-thelen.org/comp-hist/vs-mit-apollo-guidance.html

The last one has a link to a fascinating powerpoint presentation.
 
M

Martin Griffith

Jan 1, 1970
0
Greetings dwellers of SED: I was recently going through a datasheet
and came across an oddity of a package. It's called a "ceramic dual
flatpack" (page 11: http://focus.ti.com/lit/ds/symlink/sn74ahct541.pdf).
It does not appear to be surface mountable, as the leads would have to
be bent down to touch the PCB. It is not through hole mountable, as
the leads go straight out.

Can anybody tell me what this package type is used for?

Thanks,

-Michael


Wirewrap?


Martin
 
This is a military-grade package going back to the 60s. You used a
special die in a press to form the leads and then you weld, yes, weld,
the leads to the PCB. Early digital computers in missiles were built
out packages like these.

When I used these packages back around 1990 we used our own special
die to shorten and form the leads for surface mounting, then just
soldered the package to our PCB as if it was a regular surface mount
package. It worked fine.
 
E

Eeyore

Jan 1, 1970
0

The usual over-simplification ....

"Nowadays it is well-documented that Jack Kilby of Texas Instruments and Robert
Noyce of Fairchild Semiconductor independently conceived of the idea at roughly
the same time in 1958/59"

Yet ....

"The integrated circuit was first conceived by a radar scientist, Geoffrey W.A.
Dummer (born 1909), working for the Royal Radar Establishment of the British
Ministry of Defence, and published in Washington, D.C. on May 7, 1952 "
http://en.wikipedia.org/wiki/Integrated_circuit

Now, the technology of the day wasn't up to the task in 1956 when he tried to
make one but he certainly conceived the idea first.

Graham
 
When I used these packages back around 1990 we used our own special
die to shorten and form the leads for surface mounting, then just
soldered the package to our PCB as if it was a regular surface mount
package. It worked fine.

Yeah, I guess I should have said you *may* weld them if your
application needs it. Apparently missiles needed it, or maybe
soldering wasn't judged reliable enough at the time. It's a pretty
serious heavy-duty package at any rate.
 
The usual over-simplification ....

"Nowadays it is well-documented that Jack Kilby of Texas Instruments and Robert
Noyce of Fairchild Semiconductor independently conceived of the idea at roughly
the same time in 1958/59"

Yet ....

"The integrated circuit was first conceived by a radar scientist, Geoffrey W.A.
Dummer (born 1909), working for the Royal Radar Establishment of the British
Ministry of Defence, and published in Washington, D.C. on May 7, 1952 "http://en.wikipedia.org/wiki/Integrated_circuit

Now, the technology of the day wasn't up to the task in 1956 when he tried to
make one but he certainly conceived the idea first.

Graham

Well Julius Lilienfield thought of the MOSFET first too...
 
J

JosephKK

Jan 1, 1970
0
Michael [email protected] posted to sci.electronics.design:
Greetings dwellers of SED: I was recently going through a datasheet
and came across an oddity of a package. It's called a "ceramic dual
flatpack" (page 11:
http://focus.ti.com/lit/ds/symlink/sn74ahct541.pdf). It does not
appear to be surface mountable, as the leads would have to be bent
down to touch the PCB. It is not through hole mountable, as the
leads go straight out.

Can anybody tell me what this package type is used for?

Thanks,

-Michael

Presuming that you are talking about the "W" package, that is the old
standard "flat-pack" without preformed leads. It is intended for
surface mount after lead forming. It is an out of date package style
dating back to the early 1970's or so.
 
J

JosephKK

Jan 1, 1970
0
Eeyore [email protected] posted to
sci.electronics.design:
The usual over-simplification ....

"Nowadays it is well-documented that Jack Kilby of Texas Instruments
and Robert Noyce of Fairchild Semiconductor independently conceived
of the idea at roughly the same time in 1958/59"

Yet ....

"The integrated circuit was first conceived by a radar scientist,
Geoffrey W.A. Dummer (born 1909), working for the Royal Radar
Establishment of the British Ministry of Defence, and published in
Washington, D.C. on May 7, 1952 "
http://en.wikipedia.org/wiki/Integrated_circuit

Interesting.

Now, the technology of the day wasn't up to the task in 1956 when he
tried to make one but he certainly conceived the idea first.

Too bad you followed up with two non-sequiters in the same sentence.
 
Top