Homebrew PCBs

Hi Lanny,
I was just wondered what frequency you will be operating the microwave circuit, and what board you are using. As I understand it you can use FR4 up to 2GHz, beyond this you need special board which is made of a low-loss dielectric material. Also if you are using standard FR4, is there not a problem due to tolerances/variations associated with the board thickness over an area, as this will change the characteristic impedance of micro-strip lines - along the line (if you can see what I mean).

Cheers,

Gavin

lnphoenix <Lnphoenix@...> wrote:                             I'm about to make a microwave test PCB for the first time, using tone
 transfer. The PCB size is about 4"x4" with the bottom layer is served
 as a ground plane. How do I mask the bottom layer so the copper
 remained intact during contact with ferric chloride? Vaseline? Masking
 tape? Huge tip marking pen? Some kind of chemical etching resist?
 
 TIA
 Lanny
 
 
     
                                       

       

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