Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!gatech!emory!stiatl!john
From: john@stiatl.UUCP (John DeArmond)
Newsgroups: sci.electronics
Subject: Re^2: Through-plating PCB's
Message-ID: <6684@stiatl.UUCP>
Date: 29 Aug 89 13:24:05 GMT
References: <4003@csd4.csd.uwm.edu> <10040019@hprmokg.HP.COM>
Organization: Sales Technologies Inc., "The Procedure IS the product"
Lines: 28

barry@hprmokg.HP.COM (Barry Fowler) writes:

>The electronics industry doesn't plate traces on pc boards.  They etch
>the copper off already plated boards.  

>Take it off,  take it off....

Not true.  While most low and medium production boards are etched, high
volume boards are quite often made from an additive process.

Back to the point..

Plated-through holes are done BEFORE etching.  The board is drilled on
an NC drill.  Next the holes are coated with a conductive substance and 
then the board is plated.  Metal is deposited on top of the conductive
coating.  Then the board traces are applied and etched.

While the process is somewhat tedious and particular regarding chemistry 
control, it is well within the capabilities a well-equipped prototype 
or hobby shop.  Kepro, among others, sells desktop equipment and chemicals.
Check your EEG or EBG for an address or phone.

John

-- 
John De Armond, WD4OQC                     | Manual? ... What manual ?!? 
Sales Technologies, Inc.    Atlanta, GA    | This is Unix, My son, You 
...!gatech!stiatl!john    **I am the NRA** | just GOTTA Know!!!