Component Damage

On Tue, 20 Jun 2017 20:16:48 +0100, "Ian Field"
<gangprobing.alien1@virginmedia.com> wrote:

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.

IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

They pack *EVERYTHING* in anti static bags - there was a time anti static
bags alerted you to the need for special handling.

All semiconductors need special handling. Usually I just wet my hands
and ground myself. That is plenty. Wet hands cant cause static
electricity. No other passive components need that (as far as I know).
Tubes are safe too.

 

[Ian Field]

"Cursitor Doom" <curd@notformail.com> wrote in message
newsi66uj$gsh$10@dont-email.me...

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

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

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

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.

 

[Ian Field]

"John Robertson" <spam@flippers.com> wrote in message
news:c66dnT9O6dfxqtXEnZ2dnUU7-cmdnZ2d@giganews.com...

On 2017/06/16 1:48 PM, Ian Field wrote:


"Cursitor Doom" <curd@notformail.com> wrote in message
newshpjo9$ckb$2@dont-email.me...
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT

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

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.

IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

They pack *EVERYTHING* in anti static bags - there was a time anti static
bags alerted you to the need for special handling.

 

[Ian Field]

<oldschool@tubes.com> wrote in message
news:7lsikchkjfl0o8e6644nhnvb04d53nc1k0@4ax.com...

On Tue, 20 Jun 2017 20:16:48 +0100, "Ian Field"
gangprobing.alien1@virginmedia.com> wrote:

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.

IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

They pack *EVERYTHING* in anti static bags - there was a time anti static
bags alerted you to the need for special handling.

All semiconductors need special handling. Usually I just wet my hands
and ground myself. That is plenty. Wet hands cant cause static
electricity.

Wrong - your hands are essentially wet by default. Wet hands simply provide
a lower impedance jump off point for that fat blue spark.

Working on a PC - I rest my bare elbow on the metal case so I'm at the same
potential as what the PC thinks is earth. Some people insist on unplugging
the mains - but it makes no difference from the ESD point of view if you do
it properly.

Handling individual ICs, I breathe on them so the slight humidity provides a
leakage path between the pins. I always plant my hand on the anti static mat
before putting the chip down to make sure I'm at the same potential as where
I'm putting the chip. Deploying the part is same as working on a PC - touch
the ground plane while introducing the chip to its socket.

 

[whit3rd]

On Tuesday, June 20, 2017 at 1:15:14 PM UTC-7, olds...@tubes.com wrote:

On Tue, 20 Jun 2017 20:16:48 +0100, "Ian Field"

All semiconductors need special handling. Usually I just wet my hands
and ground myself. That is plenty.

Not sure about the 'wet hands' part (your hands have lower skin resistance
than a ground strap), and the 'ground myself' is likewise a problem. We
all have to unclip from the leash at some point.

Installing RAM, I generally unseal the package, then hold onto the computer
chassis with my left hand while installing the module with my right. Earth
ground is not a requirement, just that the conductive packaging, the
installer, and the computer's groundable parts are all at the same potential.
If you have groundstrap and conductive mat, you STILL need also to ground the
computer. Sometimes, this is done with a dummy cord, ground-only, to the power
supply, but that's just SO ugly: a power cord that doesn't connect power !!ick!!

 

[Ian Field]

"whit3rd" <whit3rd@gmail.com> wrote in message
news:08db9c34-ec80-45e9-a6a2-d84bd5e19039@googlegroups.com...

On Tuesday, June 20, 2017 at 1:15:14 PM UTC-7, olds...@tubes.com wrote:
On Tue, 20 Jun 2017 20:16:48 +0100, "Ian Field"

All semiconductors need special handling. Usually I just wet my hands
and ground myself. That is plenty.

Not sure about the 'wet hands' part (your hands have lower skin resistance
than a ground strap), and the 'ground myself' is likewise a problem. We
all have to unclip from the leash at some point.

Installing RAM, I generally unseal the package, then hold onto the
computer
chassis with my left hand while installing the module with my right.
Earth
ground is not a requirement, just that the conductive packaging, the
installer, and the computer's groundable parts are all at the same
potential.
If you have groundstrap and conductive mat, you STILL need also to ground
the
computer. Sometimes, this is done with a dummy cord, ground-only, to the
power
supply, but that's just SO ugly: a power cord that doesn't connect power
!!ick!!

You didn't change much from what I said.

 

[Michael A. Terrell]

Cursitor Doom wrote:

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 transistor 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?

We had a pair of large (160 gallon) three phase air compressors at
Microdyne. They ran the crimping tools, as well as supplying compressed
air for two leased air nozzles with a radioactive element to prevent
static buildup when cleaning flux from new circuit boards.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)