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| From: | |
| Reply To: | TechNet E-Mail Forum. |
| Date: | Wed, 12 Jun 2002 14:24:32 -0400 |
| Content-Type: | text/plain |
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I think Barbara is trying to modify the assembly, not profile it. We have
not done it here.
So, my advice would be a SWAG.
But to follow your thinking,
a predictable delta between air and balls. . . . there might be good rules
of thumb for "typical" designs and a give piece of rework equipment, but the
delta would certainly depend on the method of heat transfer. Radiant and
convection heaters would not have the same rules of thumb. Even the type of
nozzle and convection efficiency change the typical delta between the air
temp and the component temp.
Be certain that you are using the data from Steve appropriately.
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]]On Behalf Of WEEKES, MICHAEL
> HS-SNS
> Sent: Wednesday, June 12, 2002 11:14 AM
> To: [log in to unmask]
> Subject: Re: [TN] Access to balls on a BGA from the opposite side of the
> B oard
>
>
> Have to go through from the other side of the PWB.
> There are some predictable temp deltas between a free floating
> t/c adjacent
> to balls - contact Steve Gosowski at Air Vac in CT.
>
> -----Original Message-----
> From: Barbara Burcham [mailto:[log in to unmask]]
> Sent: Tuesday, June 11, 2002 4:13 PM
> To: [log in to unmask]
> Subject: [TN] Access to balls on a BGA from the opposite side of the
> Board
>
>
> We need to wire to two balls inside the perimeter of the BGA.
> Any one done this?
> Got ideas?
>
> Thanks,
> Barbara J. Burcham, CID
> PCB Designer
> [log in to unmask]
>
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