Component Damage

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One of the books I picked up on faultfinding and troubleshooting whilst  
in London the other day (title escapes me but I can find it if anyone  
cares) states that:

a) A bipolar transitor may be permanently damaged by dropping it on a  
concrete floor from a height of over 4'. (I'm paraphrasing but that's the  
gist of it).

Elsewhere it states that:

b) static sensitive components can be damaged by careless use of air  
dusters, which can build up a static charge, in their vicinity.  

Whilst I'm prepared to place some faith in assertion b) I'm reluctant to  
do so in the case of a). However, I'm more concerned with b) because I  
recently purchased a fair sized air compressor for blowing dust out of  
the insides of test equipment which is of course considerably more  
powerful than the aerosol cans the author was thinking about when he  
asserted b).
Has anyone ever caused damage to static-sensitive components through the  
use of compressed air? Is this something we really need to be mindful of?

Re: Component Damage
On Tuesday, 13 June 2017 21:24:50 UTC+1, Cursitor Doom  wrote:
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I'd first be mindful of mechanical damage from doing that.
When was the book written? Germanium?


NT

Re: Component Damage
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

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Haha! I think even those old germanium diodes would easily cope with a  
four foot fall!


Re: Component Damage
On Tuesday, 13 June 2017 22:03:32 UTC+1, Cursitor Doom  wrote:
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I think those would be some of the more fragile items. Many have an extremely thin filament stretching a few mm with no support at all.


NT

Re: Component Damage
On Tue, 13 Jun 2017 14:38:44 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

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Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

void _-void-_ in the obvious place

  

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Re: Component Damage


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The first successful anti aircraft shell proximity fuze that could be fired  
out of a gun had 3 hearing aid style tubes.

The thyratron obviously isn't a hearing aid tube - its about the sixe &  
shape of the glass envelope.  


Re: Component Damage
On Tuesday, June 13, 2017 at 2:03:32 PM UTC-7, Cursitor Doom wrote:
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Oh, no; a point contact diode can easily jar out of spec.   There was even
an old device (the 'coherer') which reformed a rectifying contact by
motorized shaking during normal operation.

Re: Component Damage


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AFAIK: the point is "burned in" during manufacture. The weld is pretty much  
the alloying process that creates the PN junction.

They're much less fragile than the old catswhisker/galena crystal.  


Re: Component Damage
On Tue, 13 Jun 2017 20:59:53 -0000 (UTC), Cursitor Doom

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Dont try that with a vaccuum tube!  


Re: Component Damage


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I've seen one or two bounce - not very often though.  


Re: Component Damage


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diodes would be OK but die mounting and bond wires in some germanium  
transistors was well, err - a bit amateurish.

Nowadays; suppliers pack *ANY* components in anti-static bags - it used to  
be some sort of clue which bits to handle with care.

There's some unexpected parts on the vulnerable list, so maybe they have a  
point.

molded semiconductors can be subjected to pretty much anything that doesn't  
break the case.  


Re: Component Damage
On Fri, 16 Jun 2017 21:48:37 +0100, Ian Field wrote:

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Are you the same Ian Field that has authored several books on UHF/VHF  
subjects?


Re: Component Damage
On Sunday, June 18, 2017 at 11:44:48 AM UTC-4, Cursitor Doom wrote:
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Plasma physics too...  

oh sorry that was Ion Fields. :^)

George H.  

Re: Component Damage


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I rarely play with anything higher than a few MHz.

The "pill" molded transistors in early TV tuners weren't so robust - they  
weren't exactly molded as such, they were 2 plastic shells glued together.  


Re: Component Damage
On 2017/06/16 1:48 PM, Ian Field wrote:
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IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

John ;-#)#


Re: Component Damage
compressed air can over-speed some small fans...

m


Re: Component Damage
On 6/19/2017 3:43 PM, John Robertson wrote:
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For the same reason drive through ATMs have instructions in Braille.

One kind of something is cheaper to inventory than two kinds of
something.

If you don't inventory non-static bags, nobody gets sensitive parts
in the wrong bags.


--  
Jeff-1.0
wa6fwi
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Re: Component Damage
On 2017/06/19 2:07 PM, Foxs Mercantile wrote:
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Now that makes sense. I imagine that the cost of anti-static vs regular  
bags is minuscule when you buy at Digi-Keys volume.

Thanks,

John :-#)#

Re: Component Damage
wrote:

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Not really.  Drive-up ATMs have Braille because it is not uncommon for
a blind person to take a cab or have a friend drive them to the bank
and use the ATM from the back seat or get out and walk to the drive-up
ATM while their friend monitors them for safety.  The National
Federation of the Blind insisted that ALL ATMs provide a means for use
by blind people.  

Re: Component Damage
On 19.06.2017 22:43, John Robertson wrote:
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Most likely for compliance reasons. Thanks to the general CYA style
over-protectiveness, ESD safety rules are going postal. In various
places, rather than using common sense and somewhat educated employees,
they don't allow any sort of non-ESD-protected items on the production
floors any more. Having the sockets delivered in a non-dissipative
plastic bag would have some QC lunatics throw a hissy fit and run
screaming because they found something (the bag) that was (allegedly)
compromising the ESD safety of the factory :)


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