pcb'S

[gstopp at fibermux.com]

     Yes the setup fees are a bitch, I agree! I had to go through 2 
     revisions of the ASM-1 before I went to the production batch. See the 
     CAD software that I used (Protel shareware for DOS) does come with a 
     Gerber-file generator utility so you can make your film plot data 
     files, but it *doesn't* come with a companion CAD schematic editor and 
     net-check utility. Therefore the first version of the circuit board 
     *will* have a few mistakes, like forgotten power traces and swapped 
     pins etc. One may think that it is possible to design a complex 
     circuit layout error-free without a net-check utility, but that's like 
     believing that you can learn to snow ski without ever falling down. 
     Ha!
     
     Anyway, armed with the knowledge that you will screw up at least a 
     little, you can be reassured by the fact that if you do things right 
     you won't need to pay another setup fee for your second revision. All 
     you need to do is make all of your corrections without changing any of 
     the holes. See the setup data (an NC paper tape, in my case) tells the 
     PC-making machine where to move the tooling bits for the board 
     fabrication process. The traces are on the film. So, if you can come 
     up with a new film layer that doesn't change any hole locations, you 
     can keep your setup data files and just swap out old film layers for 
     new. You do have to pay to make more film layers, however.
     
     So, in a nutshell, here's the typical costs for making a PCB:
     
     * CAD costs - nothing if you use shareware
     
     * Initial film costs - $10-15 per layer:
     
        1. Silkscreen (not required but way way useful)
        2. Top layer
        3. Bottom layer
        4. Pad Master (drill guide)
     
        A Solder Mask film is also a good thing but you can instruct the
        PCB house to use the Pad Master as the solder mask.
     
     * Prototype setup for 1 or 2 pieces - $300 (this is the first big
       chunk o' money)
     
     * Debug and shoot 1 or 2 new films (top and bottom layer probably) - 
       $10-15 per layer
     
     * Slip in the new film, with no new setup costs, and order your batch.
       The more you order, the cheaper per board. The longer the lead time,
       the cheaper per board. At 4 weeks the price hits bottom. Depending
       on the circuit board, you will pay between $10 and $75 per board.
       For example, a typical Oberhiem SEM clone may cost $30 per at a
       quantity of 50 at a lead time of 4 weeks - that's $1500 plus tax (if
       you don't have a resale number). This is the biggest chunk o' money.
     
     Total = $60 + $300 + $30 + $1500 = $1890 plus tax.
     
     If you did a nice job and you don't really need all 50, you can sell 
     most of them (at a little more than you paid for them) and get your 
     money back, and have a few circuit boards to play with in the end.
     
     - Gene
     gstopp at fibermux.com


______________________________ Reply Separator _________________________________
Subject: pcb'S
Author:  KLEIN_B at A1.WDC.COM at ccrelayout
Date:    7/26/96 8:45 AM


I seem to have missed the original message starting this thread but 
in regards to having pcb's made and/or quoted, it looks like you
do indeed pay mostly for the setup charge - not so much for the
board size or quantity.  So it would be better to find out what their 
full-size (before cut) panel size is and either cram as many boards of 
one type on it as you can, or put several layouts onto one sheet and 
make several boards at a time.  Also when you ask for quotes say
"how many of these can you make for me for $300?", because its going 
to cost you around that anyway.
     
     
klein_b at a1.wdc.com