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Date: | Thu, 05 Sep 1996 10:07:41 -0700 |
Content-Type: | text/plain |
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[log in to unmask] wrote:
>
> Questions from a telecomms designer:
>
> What is the max continuous operating temperature for a COMPONENT on a vertically
> orientated PCB (without thermal management) without causing "damage" to the
> substrate?
>
> Has anyone derived a time/temp situation in reflow that would result in
> significant degregation of the PCB such that personnel might be affected by
> toxic fumes?
>
> Thanks, George Wheadon
>
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The MAX. Component temperature is dependent upon the component
specification and should be available from the supplier specs.
A typical FR4 PCB is capable of continuously operating at 60-70 deg. C in
a product. All applications should be designed to stay well below Tg
temperature of the board material in use.
The PCB can withstand the reflow temperature, 200 - 240 deg. C for a
short duration which is the reflow cycle of 1.5-2.5 minute. If fumes are
comming off the FR4 PCB, the temperature is too hot and the epoxy will be
breaking down and will cause reliability issues in the field.
--
Pratap Singh
Tel./Fax: 512-255-6820
e-mail: [log in to unmask]
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