OP-AMP Long-Term Reliability

[Cursitor Doom]

Gentlemen,

How reliable are the old 'tin-can' encapsulated op-amps from say 40
years ago? I'm talking about the ones that look like large transistors
and have typically 8 leads in the TO5-8 package. I'm unable to provide
a part number as these don't have one as such. Could be a 741 perhaps
but I can't be certain. Are they known to fail?

thanks.
--

No deal? No problem! :-D

 

[John Robertson]

On 2020/01/18 1:11 p.m., Cursitor Doom wrote:

Gentlemen,

How reliable are the old 'tin-can' encapsulated op-amps from say 40
years ago? I'm talking about the ones that look like large transistors
and have typically 8 leads in the TO5-8 package. I'm unable to provide
a part number as these don't have one as such. Could be a 741 perhaps
but I can't be certain. Are they known to fail?

thanks.

Many solid state devices from that era are still running. Physical
damage (moisture working in via the leads) is one primary cause of
failure. If the leads look good then chances are fairly good the device
will work.

I use lots of 30 to 40+ year old components all the time for servicing
our classic arcade games. Most are perfectly good. Other than
electrolytic capacitors...they definitely have a shelf life/best before
date!

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

On Saturday, 18 January 2020 21:11:24 UTC, Cursitor Doom wrote:

Gentlemen,

How reliable are the old 'tin-can' encapsulated op-amps from say 40
years ago? I'm talking about the ones that look like large transistors
and have typically 8 leads in the TO5-8 package. I'm unable to provide
a part number as these don't have one as such. Could be a 741 perhaps
but I can't be certain. Are they known to fail?

thanks.

The problem components from that era are lytics of course and glob-top transistors.


NT

 

[Cursitor Doom]

On Sat, 18 Jan 2020 15:02:31 -0800 (PST), tabbypurr@gmail.com wrote:

On Saturday, 18 January 2020 21:11:24 UTC, Cursitor Doom wrote:
Gentlemen,

How reliable are the old 'tin-can' encapsulated op-amps from say 40
years ago? I'm talking about the ones that look like large transistors
and have typically 8 leads in the TO5-8 package. I'm unable to provide
a part number as these don't have one as such. Could be a 741 perhaps
but I can't be certain. Are they known to fail?

thanks.

The problem components from that era are lytics of course and glob-top transistors.

OK, I have to know.. "Glob-top"??
--

No deal? No problem! :-D

 

[Cursitor Doom]

On Sat, 18 Jan 2020 14:12:19 -0800, John Robertson <spam@flippers.com>
wrote:

Many solid state devices from that era are still running. Physical
damage (moisture working in via the leads) is one primary cause of
failure. If the leads look good then chances are fairly good the device
will work.

No sign of corrosion at all on the leads.

I use lots of 30 to 40+ year old components all the time for servicing
our classic arcade games. Most are perfectly good. Other than
electrolytic capacitors.

So do I. The question wasn't about NOS components, but components that
have been in service for decades.


--

No deal? No problem! :-D

 

[Trevor Wilson]

On 19/01/2020 8:11 am, Cursitor Doom wrote:

Gentlemen,

How reliable are the old 'tin-can' encapsulated op-amps from say 40
years ago? I'm talking about the ones that look like large transistors
and have typically 8 leads in the TO5-8 package. I'm unable to provide
a part number as these don't have one as such. Could be a 741 perhaps
but I can't be certain. Are they known to fail?

**No. Provided supply Voltages remain within the limits set by the
manufacturer, metal can OP amps, transistors, etc are phenomenally
reliable. For a long time, all MIL-spec semiconductors were metal can
only. They might still be, but I doubt it. In the early days of plastic
encapsulation, some problems were notable. Mostly with power devices.
Things have improved markedly over the years, but you will likely never
approach the reliability of a metal can device by using plastic.


--
Trevor Wilson
www.rageaudio.com.au

 

On Sunday, 19 January 2020 01:23:38 UTC, Cursitor Doom wrote:

On Sat, 18 Jan 2020 15:02:31 -0800 (PST), tabbypurr wrote:
On Saturday, 18 January 2020 21:11:24 UTC, Cursitor Doom wrote:
Gentlemen,

How reliable are the old 'tin-can' encapsulated op-amps from say 40
years ago? I'm talking about the ones that look like large transistors
and have typically 8 leads in the TO5-8 package. I'm unable to provide
a part number as these don't have one as such. Could be a 741 perhaps
but I can't be certain. Are they known to fail?

thanks.

The problem components from that era are lytics of course and glob-top transistors.

OK, I have to know.. "Glob-top"??

http://www.ichom.org/Overig-499982/Connectoren-schakelaars-kabels-FAIRCHILD-Glob-Top/

The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much.


NT

 

[John Robertson]

On 2020/01/18 5:26 p.m., Cursitor Doom wrote:

On Sat, 18 Jan 2020 14:12:19 -0800, John Robertson <spam@flippers.com
wrote:

Many solid state devices from that era are still running. Physical
damage (moisture working in via the leads) is one primary cause of
failure. If the leads look good then chances are fairly good the device
will work.

No sign of corrosion at all on the leads.

I use lots of 30 to 40+ year old components all the time for servicing
our classic arcade games. Most are perfectly good. Other than
electrolytic capacitors.

So do I. The question wasn't about NOS components, but components that
have been in service for decades.

My first sentence in my first paragraph was my (getting tired of 'my')
experience about original esolid state devices still running.

Do please read what is written, I'm the only one here who is allowed to
make the mistake of not reading entire posts before responding!

John ;-#)#

 

[Cursitor Doom]

On Sat, 18 Jan 2020 19:35:36 -0800 (PST), tabbypurr@gmail.com wrote:

http://www.ichom.org/Overig-499982/Connectoren-schakelaars-kabels-FAIRCHILD-Glob-Top/

The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much.

Ah. Ok. I have a few hundred of those but some obscure part numbers
and all PNP so are unlikely to be called into service here.
--

No deal? No problem! :-D

 

[Jeff Liebermann]

On Sun, 19 Jan 2020 10:10:50 +0000, Cursitor Doom
<curd@notformail.com> wrote:

On Sat, 18 Jan 2020 19:35:36 -0800 (PST), tabbypurr@gmail.com wrote:


http://www.ichom.org/Overig-499982/Connectoren-schakelaars-kabels-FAIRCHILD-Glob-Top/

The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much.

Ah. Ok. I have a few hundred of those but some obscure part numbers
and all PNP so are unlikely to be called into service here.

Those bring back not so fond memories. The black potting epoxy was
optically transparent to infrared light. I had a hell of a time
dealing with weird problems in the 1960's until I found the light
sensitivity problem with those transistors. It took about a year for
Fairchild to clear their inventory and screw their unsuspecting
customers by continuing to sell these devices. Eventually, they
changed over to the "PN" (TO-92) style package, which initially was
made from silicon epoxy instead of epoxy-B. Silicon epoxy shrinks
slightly at high temperatures, causing the corrosive fluxes from the
wave soldering equipment to creep up the transistor leads by capillary
action, and corrode the leads and chip. We had to x-ray the dead
parts to determine the failure mode and guess the cause. It usually
took about a month for the transistors to rot to death. I had a
difficult time getting Fairchild to understand that having *ALL* the
transistors on a PCB fail almost simultaneously after only a month was
sufficient grounds for suspecting that something might be wrong with
the parts. They eventually switched to epoxy-B, but only after again
unloading their defective inventory on unsuspecting customers. There
was also a problem with the UA2136 IF amp/detector IC, where chips
made in different Fairchild factories produced radically different
performance and stability. I took great pride in personally removing
Fairchild from the approved vendor/manufacturers list, and finding
alternate sources for about $2.5 million/year of their components.
When I mentioned this to the sales rep, he acted like he didn't care
or it wasn't important.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Trevor Wilson]

On 20/01/2020 9:55 am, Jeff Liebermann wrote:

On Sun, 19 Jan 2020 10:10:50 +0000, Cursitor Doom
curd@notformail.com> wrote:

On Sat, 18 Jan 2020 19:35:36 -0800 (PST), tabbypurr@gmail.com wrote:


http://www.ichom.org/Overig-499982/Connectoren-schakelaars-kabels-FAIRCHILD-Glob-Top/

The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much.

Ah. Ok. I have a few hundred of those but some obscure part numbers
and all PNP so are unlikely to be called into service here.

Those bring back not so fond memories. The black potting epoxy was
optically transparent to infrared light. I had a hell of a time
dealing with weird problems in the 1960's until I found the light
sensitivity problem with those transistors. It took about a year for
Fairchild to clear their inventory and screw their unsuspecting
customers by continuing to sell these devices. Eventually, they
changed over to the "PN" (TO-92) style package, which initially was
made from silicon epoxy instead of epoxy-B. Silicon epoxy shrinks
slightly at high temperatures, causing the corrosive fluxes from the
wave soldering equipment to creep up the transistor leads by capillary
action, and corrode the leads and chip. We had to x-ray the dead
parts to determine the failure mode and guess the cause. It usually
took about a month for the transistors to rot to death. I had a
difficult time getting Fairchild to understand that having *ALL* the
transistors on a PCB fail almost simultaneously after only a month was
sufficient grounds for suspecting that something might be wrong with
the parts. They eventually switched to epoxy-B, but only after again
unloading their defective inventory on unsuspecting customers. There
was also a problem with the UA2136 IF amp/detector IC, where chips
made in different Fairchild factories produced radically different
performance and stability. I took great pride in personally removing
Fairchild from the approved vendor/manufacturers list, and finding
alternate sources for about $2.5 million/year of their components.
When I mentioned this to the sales rep, he acted like he didn't care
or it wasn't important.

**Oh, now that is interesting stuff.

--
Trevor Wilson
www.rageaudio.com.au