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  for Metal Finishing since 1989
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MIDS - selective plating of polymers

1998

Hi!

I need some help selecting polymers for a product we are developing.

Tradional antennas (mobile 'phones etc) use wire , which is encapsulated in an injection moulding process to arrive at a finished product. As frequencies get higher and antennas are required to operate at different bands (e.g., GSM, DCS, PCN) it becomes more and more difficult package the antenna and hold tolerences. The structures get more complex.

We are developing a process inhouse that involves 2 mouldings one moulded over the other.This then goes through a plating process which plates only the exposed surfaces of the first moulding.

Can anyone help with suggestions on polymer selection, an ABS or PC/ABS blend (for additional mechanical strength) would seem to be the logical choice for the plateable polymer. What should I use for the second?

I am also interested in using PP as much as possible as it is the preferred material for use in antenna systems due to the fact that it does not absorb the radiating signal.

I had used a combination of PC/ABS for the plateable polymer and PVC for the second or mask polymer which worked well in the plating process. The PVC, unfortunately, killed the antenna, very low radiating efficiency.

The plating itself needs to be Cu. and the volumes will be large so the process must be economic.

Is there anyone that can make some suggestions, believe me all suggestions are welcome!

Thanks for you time!

John

John Garvey
wireless technologies - Dublin, Ireland

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Polypropylene is plateable; in fact I believe that a substantial portion of plated-on-plastic automobile bezels and trim items were polypropylene before ABS overtook it; so it won't be a good non-plating surface, but it might be an alternate to the ABS for the plated surface.

PVC and its plastisols are indeed the most common masking material; sorry to hear that it's not ideal for your situation. Hopefuly someone will offer ideas.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
1998