Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Teflon PCB's

ScottM

#17917

Teflon PCB's | 16 October, 2001

Anybody have any experience with SMT and PTH assembly on Teflon Bare Boards?

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lileubie

#17919

Teflon PCB's | 16 October, 2001

What do you need to know?

~ Glenn

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ScottM

#17942

Teflon PCB's | 17 October, 2001

Any processes that I need to be aware of that differs from standard FR4 during reflow and wave soldering?

I've read one of the problems is the thermal expansion of teflon is quite different from copper. I've also seen a "blurb" where teflon absorbs moisture yet another "blurb" says lack of moisture absorbtion is one of it's better properties (???).

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#18010

Teflon PCB's | 26 October, 2001

We process no Teflon boards.

Companies, such as Rogers and Taconic, make laminates of Polytetrafluoroethylene [PTFE] er �Teflon�. Common �Teflon� laminates are: * Woven glass / PTFE * Random microfiber glass / PTFE * Ceramic / PTFE * Woven glass / ceramic / PTFE * Woven quartz / PTFE

Lots of fabricators use �Teflon� laminates to make boards. Poly Circuits and PC Dynamics are among fabricators that specialize in �Teflon� boards. �Teflon� boards can be: * Two sided. * Multilayer. * Mixed dielectric including either different layers of material types or intermixing of two different substrates on the same layer. * Metal backed or cored.

We talked about building a woven glass / PTFE board a while ago. As I recall: STORAGE: No issues CONVEYOR: No Issues USE OF PALLETS: No Issues MASS SOLDERING: No Issues HAND SOLDERING / REWORK: No Issues. Although this IS the dicest area. The copper cladding on the dielectric limits the temperature exposure of the laminate. If you lift a pad and then rework it, you probably will change the circuit behavior.

Comparing woven glass / PTFE to FR-4: * CTE [x, y, z] are similar. * Copper bond strength is similar.

Consider talking to the fabricator and some of their customers.

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Reflow Ovens thermal process improvement