Homebrew PCBs

In a message dated 20-Feb-02 11:00:13 Central Standard Time, 
jim.ubersetzig@... writes:


> How thick can you make a PCB ?  
> 
> 

Jim:  I haven't "looked ahead" to see if someone with more cerebral mass has 
already more intelligently answered, already, but here's MY 2¢ "hobby 
experience" worth toward this question:  

"FR-4", the Fire Retardent green epoxy-glass presently more common than the 
previously-popular G-10 "same thing" comes in 1/64" through 1/8" thick 
versions with NO copper at all, copper only on ONE side, copper on BOTH 
sides, 1/2, 1.0, and 2.0 oz. "weights) (the copper-thickness; I never learned 
how thick an "ounce" is!).  The 1/8" is plenty tough!  But if you needed 
something as thick as 1/4", to drive Sherman tanks across (that'd mess up the 
nicest solder-masks and PTH!!!), I THINK you would have to do one of TWO 
things:  Order some SPECIAL-made, or find  who may have already done so, and 
still has some on hand, he's willing to sell, or two, GLUE-UP some, putting 
non-copper-sides together.  I have never learned the howzits of multi-layer 
PCB-makin', but in that, layers are heat-laminated in a 'spensive press, once 
the inner-layers of copper are etched.  Drilling is last.  Whew, a 'spensive 
mess!

Anyway, the PRESS for glueing that up to make thicker (multi-layer) boards is 
not only expensive, but incredibly powerful in terms of PSI on the laminate, 
and I THINK they can also heat the layup.  Find a jovial PCB firm near yoy 
and go hassle 'em!

Jan Rowland, old troll


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