Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:

You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..

If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.

Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

Graham

On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:



Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:

You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..

If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.

Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.

The chip and pins get real hot. The PCB assembly only gets hot enough
to perform the reflow/release operation.

Archimedes' Lever wrote:
On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:


Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.
Isn't that a PGA? Hard to cut the pins.
Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.


And all the other SMT devices will fall off the board as well - would right off the board
its a £1050 exchange PCB from Sony, but to buy new is £11,600, the whole mixer at purchase
was just over £300,000 its not a cheap piece of equipment, but then a lot of broadcast kit
is expensive and needs special knowledge to be worked on.

I saw one of our junior engineers employ your method - I prefer my guys to use time and
patience over speed and probable damage.

"f825_677" wrote in message
...
Archimedes' Lever wrote:
On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:


Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.
Isn't that a PGA? Hard to cut the pins.
Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.


And all the other SMT devices will fall off the board as well - would
right off the board its a £1050 exchange PCB from Sony, but to buy new is
£11,600, the whole mixer at purchase was just over £300,000 its not a
cheap piece of equipment, but then a lot of broadcast kit is expensive and
needs special knowledge to be worked on.

I saw one of our junior engineers employ your method - I prefer my guys to
use time and patience over speed and probable damage.

Most electronics tool suppliers stock pencil blowlamps which would be
precise enough to desolder a decent size ceramic chip, some are sold in sets
with a variety of nozzle attachments. The spread is way more precise than a
heat gun.

For smaller chips it might be worth looking out for one of those "windproof"
lighters that uses the same design of jet as the pencil blowlamp - only
smaller.

"ian field" wrote in message


Most electronics tool suppliers stock pencil blowlamps which would be
precise enough to desolder a decent size ceramic chip, some are sold
in sets with a variety of nozzle attachments. The spread is way more
precise than a heat gun.

I think he's saying that you can't apply heat to the component side at all,
even if it's directed only at the target device, because the package in
question is a hybrid with SMT parts exposed on its own surface.


For smaller chips it might be worth looking out for one of those
"windproof" lighters that uses the same design of jet as the pencil
blowlamp - only smaller.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

"Tom Del Rosso" wrote in message
...

"ian field" wrote in message


Most electronics tool suppliers stock pencil blowlamps which would be
precise enough to desolder a decent size ceramic chip, some are sold
in sets with a variety of nozzle attachments. The spread is way more
precise than a heat gun.

I think he's saying that you can't apply heat to the component side at
all,
even if it's directed only at the target device, because the package in
question is a hybrid with SMT parts exposed on its own surface.


If its going in the bin once removed, that hardly matters.

ian field wrote:

If its going in the bin once removed, that hardly matters.

I heard a story (likely true) of an MD who went round the factory after
'time', pulling components back out of the bin and replacing them on the
bench.

Graham

"f825_677" wrote in message
...


And all the other SMT devices will fall off the board as well - would
right off the board its a £1050 exchange PCB from Sony, but to buy new is
£11,600, the whole mixer at purchase was just over £300,000 its not a
cheap piece of equipment, but then a lot of broadcast kit is expensive and
needs special knowledge to be worked on.

I saw one of our junior engineers employ your method - I prefer my guys to
use time and patience over speed and probable damage.

have you seen http://www.oxygendct.com/acatalog/OxyChip_ICs.html ?

Best Regards

Steve sousa

On Tue, 25 Nov 2008 10:38:45 +0000, f825_677
wrote:

Archimedes' Lever wrote:
On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:


Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.
Isn't that a PGA? Hard to cut the pins.
Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.


And all the other SMT devices will fall off the board as well

WRONG!

A 150 degree F assembly is NOT at solder reflow temperature.

- would right off the board

WRONG! You PRE-heat the PCB. You only heat to reflow temp, the IC
chip you are removing. D'OH!

its a £1050 exchange PCB from Sony, but to buy new is £11,600, the whole mixer at purchase
was just over £300,000 its not a cheap piece of equipment,

Yeah, and you are not very brainy to think that someone would tell you
to reflow the entire board. Learn to read. Then learn how to properly
comprehend what you read.

but then a lot of broadcast kit
is expensive and needs special knowledge to be worked on.

No. It needs a proper technician. Nothing special about that. Just
educated.

I worked at General Instrument. I know about racks that cost $2M each,
and the broadcast industry had to buy our gear.

I saw one of our junior engineers employ your method

No, you didn't. Obviously, since you have a bent ****ing perception of
what "my method" is.

- I prefer my guys to use time and
patience over speed and probable damage.

You're a goddamned presumptuous idiot. The method I described IS how
one removes a part from a board. You need to learn about heat sources
and sinking. In the case I described, the heat is applied to the IC
chip. So, what gets damaged?

"Archimedes' Lever" wrote in message

On Tue, 25 Nov 2008 10:38:45 +0000, f825_677
wrote:

its a £1050 exchange PCB from Sony, but to buy new is £11,600, the
whole mixer at purchase was just over £300,000 its not a cheap piece
of equipment,

Yeah, and you are not very brainy to think that someone would tell
you to reflow the entire board. Learn to read. Then learn how to
properly comprehend what you read.

You refer to "the entire board". He refers to a PCB, but not the one you
think. The part in question is a PCB in itself. It's a hybrid module with
its own SMT parts, so you can't heat the whole part.

Google the part number and see what it looks like.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

On Wed, 26 Nov 2008 02:37:48 -0500, "Tom Del Rosso"
wrote:


"Archimedes' Lever" wrote in message

On Tue, 25 Nov 2008 10:38:45 +0000, f825_677
wrote:

its a £1050 exchange PCB from Sony, but to buy new is £11,600, the
whole mixer at purchase was just over £300,000 its not a cheap piece
of equipment,

Yeah, and you are not very brainy to think that someone would tell
you to reflow the entire board. Learn to read. Then learn how to
properly comprehend what you read.

You refer to "the entire board". He refers to a PCB, but not the one you
think. The part in question is a PCB in itself. It's a hybrid module with
its own SMT parts, so you can't heat the whole part.

YES, you can, damnit! The key is to PRE-heat the entire part so that
the transition of temperature from that temp to the temp needed to remove
the part is lower, and less likely to reflow only a portion of the pins.
It insures that ALL the pins on the chip reflow, and the chip can be
removed without damaging the PCB.

I never said anything about reflowing the entire PCB. HE DID!

I mentioned PRE-heating the PCB, and then HEATING only the part to be
removed to the reflow temperature.

Google the part number and see what it looks like.

On Wed, 26 Nov 2008 02:37:48 -0500, "Tom Del Rosso"
wrote:


"Archimedes' Lever" wrote in message

On Tue, 25 Nov 2008 10:38:45 +0000, f825_677
wrote:

its a £1050 exchange PCB from Sony, but to buy new is £11,600, the
whole mixer at purchase was just over £300,000 its not a cheap piece
of equipment,

Yeah, and you are not very brainy to think that someone would tell
you to reflow the entire board. Learn to read. Then learn how to
properly comprehend what you read.

You refer to "the entire board". He refers to a PCB, but not the one you
think. The part in question is a PCB in itself. It's a hybrid module with
its own SMT parts, so you can't heat the whole part.

YES, you can, damnit! The key is to PRE-heat the entire part so that
the transition of temperature from that temp to the temp needed to remove
the part is lower, and less likely to reflow only a portion of the pins.
It insures that ALL the pins on the chip reflow, and the chip can be
removed without damaging the PCB.

I never said anything about reflowing the entire PCB. HE DID!

I mentioned PRE-heating the PCB, and then HEATING only the part to be
removed to the reflow temperature.

Google the part number and see what it looks like.