>>> <[log in to unmask]> 09/18/01 06:16PM >>>
Chris,
Have you thought of using shield clips or fences or conductive adhesive so
the shield cover can go on as a final mechanical process? If shield covers
were a final step then they would not be exposed to high temperatures or be
sucking heat from all the components under its domain and exposing the rest
to sometimes excessive heat. What frequency is this assembly going to
operate at? Can some of the shielding be in the box it is installed in
rather than on the PCB itself?
As for rework, a nozzle can be made for every shield shape that is
nonstandard and there are many rework stations that could then remelt or
remove/replace a shield. Of course you could always get a laser if you got a
lot of extra money in your back pocket.
Dorothy Lush
> ----------
> From: Jack Crawford[SMTP:[log in to unmask]]
> Reply To: TechNet E-Mail Forum.
> Sent: Tuesday, September 18, 2001 9:49 AM
> To: [log in to unmask]
> Subject: Re: Rework of RF shields
>
> >>> Chris Murphy <[log in to unmask]> 09/17/01 11:11PM >>>
>
> Hi Technetters,
>
> I have got a board covered with SMD RF shields in front of me, ranging
> in size from 15mm x 15mm to 140mm x 40mm to 70mm square. The spacing
> between them is only 1.5mm, and they are up to 12.5mm high.
>
> I am working through the many issues with these, such as methods of P&P,
> board / shield warpage, and how we are going to reflow parts under
> them. My question is does anyone know of equipment out there that we
> can use to rework these shields? I vaguely recollect seeing a machine
> that moved a hot air nozzle rapidly around in a rectangular pattern, but
> I am not sure how effective it will be for larger shields that are
> spaced so closely together.
>
> Is there anyone else doing this type of board, and does anyone have any
> supplier contacts?
>
> Any replies greatly appreciated.
>
> Thanks,
>
> Chris Murphy,
> Production Engineering,
> Tait Electronics,
> Christchurch,
> New Zealand
>
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