Hi Anil,

I just had a few PCB checked at the Fischer office in Hong Kong. They have
used a bromine correction.

Bromine has the same characteristic as gold on the sprectrometer, so it
will add to the gold thickness. Bromine is used as a flamae retarder in FR4
(as far as I know).

Before you test gold you should calibrate the x-ray by testing a spot of
bare FR4, this reading you put into the memory and deduct later from the gold
reading.

I presume that you have some standard bromide correction stored in your
x-ray which might be too high.

Just my 0.02 Rupie

Jens



> While measuring Gold plating thickness on FR-4 material - Bromine
> correction is used - this ends up with lower than actual thickness in
our case
> - Why is this done and is Bromine a neccessary component of all FR-4
> laminates?
> Please reply earliest as my Gold plate thickness of 0.5 mic is
> measuring same on Fundamental Parameters but as low as 0.3 microns with
Bromine
> correction and my customer is pissing mad
>
> Anil Kher
> micro interconnexion pvt. ltd.
> Goa , India
>

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