A thought-provoking metaphysical conundrum...

[Paul Burridge]

Hi all,

Screw electronics for a minute.
Who would you say is the ugliest bastard currently performing in rap
music? For my money, Ja Rule takes some beating, with a face that
closely resembles a female baboon's arse (in season). But not being
over familiar with these so-called "urban artists" I could easily be
wrong and he could possibly now have been surpassed. Any other
nominations, gentlemen?

p.

 

[Winfield Hill]

Paul Burridge wrote...

Screw electronics for a minute.
Who would you say is the ugliest bastard currently performing in rap
music? For my money, Ja Rule takes some beating, with a face that
closely resembles a female baboon's arse (in season). But not being
over familiar with these so-called "urban artists" I could easily be
wrong and he could possibly now have been surpassed. Any other
nominations, gentlemen?

What's rap music? Now, what about discussing a better way to make
prototype quantities of pcb's with BGA chips on them? We're having
some success using a heat gun (with concentrator attachment) placed
about 1/4" under the pcb. The pcb is coateded with flux. When the
chip settles onto the board, remove the heat... Comments?

Thanks,
- Win

whill_at_picovolt-dot-com

 

[Spehro Pefhany]

Paul Burridge wrote...

What's rap music? Now, what about discussing a better way to make
prototype quantities of pcb's with BGA chips on them? We're having
some success using a heat gun (with concentrator attachment) placed
about 1/4" under the pcb. The pcb is coateded with flux. When the
chip settles onto the board, remove the heat... Comments?

I just got a couple of those little 8 pin BGAs (CMOS 555's, starting
small) to try it out (next time I have a proto board to make I'll add
a test section). Your approach sounds reasonable, liquid flux plus a
solder plated board heated from below.

I take it you have bigger BGAs- no problems with air blowing through
the vias? What temperature setting are you using on the heat gun?

Boy, are those things tiny...

Best regards,
Spehro Pefhany

 

[Charles W. Johnson Jr.]

Paul Burridge wrote...

What's rap music? Now, what about discussing a better way to make
prototype quantities of pcb's with BGA chips on them? We're having
some success using a heat gun (with concentrator attachment) placed
about 1/4" under the pcb. The pcb is coateded with flux. When the
chip settles onto the board, remove the heat... Comments?

Thanks,
- Win

whill_at_picovolt-dot-com

Might be better to setup a rig to allow a hot plate or smale propane burnner
to be used ,more even spread of the heating but that depends on the status
of the areas around the BGA.
perhaps a small "iron" 2 inches or so on a side, could be heated by a
propanetank plumbers tool of sorts, even closer for more concentrated
heating.

Charles

 

[Roy McCammon]

Hi all,

where's the metaphysical?

 

[Active8]

Paul Burridge wrote...

What's rap music? Now, what about discussing a better way to make
prototype quantities of pcb's with BGA chips on them? We're having
some success using a heat gun (with concentrator attachment) placed
about 1/4" under the pcb. The pcb is coateded with flux. When the
chip settles onto the board, remove the heat... Comments?

change the subject line?

sounds good. the little solder balls should align the chip to the pads
when they reflow.

Thanks,
- Win

Bob Dyllan wrote the first rap song. It's part of his basement tape,
i've been told. somehow it caught on and now every pecker head with a
microphone and an attitude is a rap star.

mike

 

[Active8]

Might be better to setup a rig to allow a hot plate or smale propane burnner
to be used ,more even spread of the heating but that depends on the status
of the areas around the BGA.
perhaps a small "iron" 2 inches or so on a side, could be heated by a
propanetank plumbers tool of sorts, even closer for more concentrated
heating.

Charles

i'd think the heat gun heating a metal plate would be less likely to
scorch the board.

mike

 

[Frank Bemelman]

Paul Burridge wrote...

What's rap music? Now, what about discussing a better way to make
prototype quantities of pcb's with BGA chips on them? We're having
some success using a heat gun (with concentrator attachment) placed
about 1/4" under the pcb. The pcb is coateded with flux. When the
chip settles onto the board, remove the heat... Comments?

Can't someone invent a doublesided adhesive pad, with a pattern of
sharp needles in it. I've got a name already: Press&Forget(tm).

 

[Glen Walpert]

Paul Burridge wrote...

What's rap music?

A contradiction in terms.

Now, what about discussing a better way to make
prototype quantities of pcb's with BGA chips on them? We're having
some success using a heat gun (with concentrator attachment) placed
about 1/4" under the pcb. The pcb is coateded with flux. When the
chip settles onto the board, remove the heat... Comments?

Everything I have read indicates that it is somewhat better to put
heat through the BGA rather than the board since most BGAs are made of
more heat tolerant materials than FR4, though some BGA are based on an
FR4 substrate. All of the good commercial rework tools apply heat
from both sides, some older equipment uses a hotplate on the bottom
and hot air on the top (like my homemade rig) but the hot setup is hot
air on both sides, which can melt the solder balls faster and with the
least temperature gradient thus lowest peak temp. Forced hot air from
both sides is claimed by some to be the only viable method for
reworking the higher temperature lead free solders for that reason,
and of course BGA production soldering is almost always done with hot
air from both sides and only rework equipment using the same
arrangement can closely duplicate production temperature profiles.

How about 2 hot air guns with nozzles, 2 C-clamps and the back of a
chair?

Regards,
Glen

 

[Glenn Gundlach]

Hi all,

Screw electronics for a minute.
Who would you say is the ugliest bastard currently performing in rap
music? For my money, Ja Rule takes some beating, with a face that
closely resembles a female baboon's arse (in season). But not being
over familiar with these so-called "urban artists" I could easily be
wrong and he could possibly now have been surpassed. Any other
nominations, gentlemen?

p.

Is rap music?
gg

 

[Ian Buckner]

"Winfield Hill" <[email protected]> schreef in bericht


Can't someone invent a doublesided adhesive pad, with a pattern of
sharp needles in it. I've got a name already: Press&Forget(tm).

Not adhesive (wouldn't work), but Fujipoly do polymer pads with
anisotropic wires (vertical) in it. Put a piece of this material
between
PCB and BGA, line up the BGA with the board pads, find a way to
push down on the BGA and you're done. I've seen BGA connectors
done like this, but they tend to be _very_ expensive. I believe you
can do this a lot simpler with guides glued on the board for protos.
Connections are good for 10GHz, number of BGA pins not important.

Regards
Ian

http://www.fujipoly.com/products/genProduct.asp?ProductName=W_Series&P
roductLine=Zebra

 

[Frank Bemelman]

Not adhesive (wouldn't work), but Fujipoly do polymer pads with
anisotropic wires (vertical) in it. Put a piece of this material
between
PCB and BGA, line up the BGA with the board pads, find a way to
push down on the BGA and you're done. I've seen BGA connectors
done like this, but they tend to be _very_ expensive. I believe you
can do this a lot simpler with guides glued on the board for protos.
Connections are good for 10GHz, number of BGA pins not important.

Regards
Ian

http://www.fujipoly.com/products/genProduct.asp?ProductName=W_Series&P
roductLine=Zebra

Hey, that looks good. I was on their website this morning for
another reason. Maybe the pads themselves aren't that expensive?
There's a pdf-file, but they won't let me see/download it.

 

[Paul Burridge]

Bob Dyllan wrote the first rap song. It's part of his basement tape,
i've been told. somehow it caught on and now every pecker head with a
microphone and an attitude is a rap star.

Well, exactly. It's sadly one of the few drawbacks of the invention of
audio amplification. Invent whatever you want; no matter how
well-intentioned it might be, and some wanker will mis-use it, as in
your example above.
As an aside, I have to say I'm quite disgusted by the way in which my
thread has been hijacked by the 'electronics brigade' - talk about
straying off-topic!
;-)

 

[Active8]

Well, exactly. It's sadly one of the few drawbacks of the invention of
audio amplification. Invent whatever you want; no matter how
well-intentioned it might be, and some wanker will mis-use it, as in
your example above.
As an aside, I have to say I'm quite disgusted by the way in which my
thread has been hijacked by the 'electronics brigade' - talk about
straying off-topic!
;-)

heh, heh... yeah, that was Win and he didn't even change the subject
[line].

BTW, i like your winders definition. i just can't understand why i can't
get it to show up when i reply. it's your sign block, isn't it?

mike

 

[Spehro Pefhany]

Well, exactly. It's sadly one of the few drawbacks of the invention of
audio amplification. Invent whatever you want; no matter how
well-intentioned it might be, and some wanker will mis-use it, as in
your example above.
As an aside, I have to say I'm quite disgusted by the way in which my
thread has been hijacked by the 'electronics brigade' - talk about
straying off-topic!
;-)

heh, heh... yeah, that was Win and he didn't even change the subject
[line].

Why would he? Almost anything would be sorta on topic. See below.

BTW, i like your winders definition. i just can't understand why i can't
get it to show up when i reply. it's your sign block, isn't it?

mike

The "-- " delimits his "sig", and that's parsed by your newsreader to
prevent that bit from being copied when you go to edit your followup.
On Agent you can get the sig block into the reply by hitting Ctrl-A
before "F" (the cursor has to be in the message window). Your
newsreader may well be different.

Best regards,
Spehro Pefhany

 

[Winfield Hill]

Active8 wrote...

Paul Burridge says...

As an aside, I have to say I'm quite disgusted by the way in which
my thread has been hijacked by the 'electronics brigade' - talk
about straying off-topic! ;-)

heh, heh... yeah, that was Win and he didn't even change the
subject [line].

If you've ever struggled with hand-mounting BGAs you must admit
it's certainly a thought-provoking metaphysical conundrum...

Thanks,
- Win

whill_at_picovolt-dot-com

 

[Active8]

On Wed, 01 Oct 2003 22:15:01 GMT, Active8


Bob Dyllan wrote the first rap song. It's part of his basement tape,
i've been told. somehow it caught on and now every pecker head with a
microphone and an attitude is a rap star.

Well, exactly. It's sadly one of the few drawbacks of the invention of
audio amplification. Invent whatever you want; no matter how
well-intentioned it might be, and some wanker will mis-use it, as in
your example above.
As an aside, I have to say I'm quite disgusted by the way in which my
thread has been hijacked by the 'electronics brigade' - talk about
straying off-topic!
;-)

heh, heh... yeah, that was Win and he didn't even change the subject
[line].

Why would he? Almost anything would be sorta on topic. See below.

well sometimes people change the subject line when they change the
subject, that's why.

LOL! it just hit me. Paul said:

more like straying on-topic.

The "-- " delimits his "sig", and that's parsed by your newsreader to
prevent that bit from being copied when you go to edit your followup.
On Agent you can get the sig block into the reply by hitting Ctrl-A
before "F" (the cursor has to be in the message window). Your
newsreader may well be different.

actually, it also works on Microplanet Gravity. i only noticed the
missing stuff a couple of times recently and it had me wondering. that
makes sense, though. it keeps alot of extraneous stuff out of the
followup.

thanks.
mike

 

[Active8]

Active8 wrote...

Paul Burridge says...

As an aside, I have to say I'm quite disgusted by the way in which
my thread has been hijacked by the 'electronics brigade' - talk
about straying off-topic! ;-)

heh, heh... yeah, that was Win and he didn't even change the
subject [line].

If you've ever struggled with hand-mounting BGAs you must admit
it's certainly a thought-provoking metaphysical conundrum...

i said you didn't change the subject ;-) <== this after posting to
Spehro that you strayed *on-topic*... this line of thinking i'm engaging
in is a conundrum. hell, just about anything goes in this thread.

mike

 

[Paul Burridge]

Active8 wrote...

Paul Burridge says...
As an aside, I have to say I'm quite disgusted by the way in which
my thread has been hijacked by the 'electronics brigade' - talk
about straying off-topic! ;-)

heh, heh... yeah, that was Win and he didn't even change the
subject [line].

If you've ever struggled with hand-mounting BGAs you must admit
it's certainly a thought-provoking metaphysical conundrum...

i said you didn't change the subject ;-) <== this after posting to
Spehro that you strayed *on-topic*... this line of thinking i'm engaging
in is a conundrum. hell, just about anything goes in this thread.

You're right! Now I would like to know what a "BGA" is. I assume this
is just another term for an SMD?

 

[Active8]

Active8 wrote...

Paul Burridge says...
As an aside, I have to say I'm quite disgusted by the way in which
my thread has been hijacked by the 'electronics brigade' - talk
about straying off-topic! ;-)

heh, heh... yeah, that was Win and he didn't even change the
subject [line].

If you've ever struggled with hand-mounting BGAs you must admit
it's certainly a thought-provoking metaphysical conundrum...

i said you didn't change the subject ;-) <== this after posting to
Spehro that you strayed *on-topic*... this line of thinking i'm engaging
in is a conundrum. hell, just about anything goes in this thread.

You're right! Now I would like to know what a "BGA" is. I assume this
is just another term for an SMD?

you could say that. it's "Bsll Grid Array" little balls of solder on the
underside of the chip. like a flip-chip but in a package. new term -
ball pitch. like baseball.

new equipment, too. you have to re-ball the bastards to resolder 'em.

mike