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Chemical used to etch Ultem for POP

Plating on Ultem and LCP  

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Hi,

I would like to know what chemical substances is best used for the adhesion process for etching on Ultem 2110 platic for the EMI plating. The problem I am facing now is that the current chemical I am using is eating up the plasic surface of not more that 0.02 mm per surface. Please assist.

Sham
Injection Molder - Singapore

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And what chemical is that that are you using, Sham. And at what operating conditions that is causing this problem? Thanks.

Ted Mooney, P.E. finishing.com Brick, New Jersey

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First of two simultaneous responses -- ++++++

I am using a compound mixture of Sulphuric acid and Chromic Acid on this etching process at 10 mins time cycle and I have also tried time cycles of 1 min ~ 30 mins. The amount of surface being eaten up by the chemical is still the same, maximum of 0.02 mm. From what I have studied is that EMI or Electroless plating process is a process in which tin layer of plating substances is added to the existing parts. Not eating up the surface...

Sham
- Singapore

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Second of two simultaneous responses -- ++++++

Adding to Ted's advise, Ultem is a registered trademark from GE. Maybe you should ask them. They know their product and how to process it, and you are the customer.

Guillermo Marrufo
Monterrey, NL, Mexico

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I see an on-line brochure for Ultem at http://www.plastoplan.com/download/ge_plastics_pdf_downloads/gep_Ultem%20Product%20Guide.pdf which says a special permanganate etch must be used (rather than the chromic-sulphuric etch which is normally used on ABS plastics). The brochure also notes the importance of using EPR (plating grade) Ultem rather than the standard grade. Good luck.

Ted Mooney, P.E. finishing.com Brick, New Jersey