Jeffery,
We routinely design boards for 155 to 200 C.
We use polyimide base materials. We also use a
gold flash (not plate) over nickel for flatness
so we can use fine pitch (.5mm & .025") parts.
Our min. trace/space is usually .008. No ceramic
parts allowed.
Hope this helps some,
Rick
At 01:25 PM 2/16/98 -0500, you wrote:
>To All -
>
>I am currently working on the design of a PWB that must continuously
>function (read as IPC-D-275 class 3) at ambient temperatures as high as
>105 degrees C.  I am seeking input as to design criteria for this
>environment.
>
>The items I have already identified include:
>
>200 degree C Tg FR-4/Gtek base material
>Conformal leaded parts where ever available
>No fine line / fine pitch design
>Teardrop at all drilled pads including vias
>
>My primary question is should we be using a "NO LEAD" finish and solder
>for these boards?
>Is there any thing I have overlooked?
>
>TIA
>Jeffrey McGlaughlin
>[log in to unmask]
>Battelle Memorial Institute
>Columbus Ohio
>
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Rick Wilson
Senior Designer
HES Houston, TX

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