Re: Homemade PCBs!

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Mitchell" <Electrontube-at-sbcglobal-dot-net> 

Or for about the same price it costs to get all the materials and things to
do photo etching,  you can have 10, 3X5 soldermask and silkscreened boards
for 65$....

Regards - Jim Mitchell
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, April 24, 2004 8:53 PM
Subject: Re: Homemade PCBs!


 > Original poster: Matthew Smith <matt-at-kbc-dot-net.au>
 >
 > Eric ("Hydrogen18") writes:
 > >I'm looking to make some homemade PCB's for a voltage multiplier, whats
 > >the best way to do this? I've seen those kits where you draw everything,
 > >but that seems pretty tedious. Is their a better way to do it at home?
 > >Also, what kind of circuit board do I want to buy? Thanks.
 >
 > Matthew replies:
 >
 > I use PCBs for all prototypes - they are NOT hard to make once you get the
 > hang of it. I use a simple photolithographic process with all home-made
 > equipment.
 >
 > Note that a PCB will be more reliable and easier to trouble-shoot than
 > prototypes using solderless breadboard or ratsnesting.
 >
 > Now that I've got my technique down to pat and have got the optimum
 > exposure times, etc., I can throw a board together in very little
 > time.  I'm even starting to use some SMD components now.
 >
 > Abbreviated steps are:
 > 1) Produce artwork on a transparency.  This could be hand-drawn or
produced
 > by CAD software such as Eagle <http://www.cadsoft.de>.
 > 2) Acquire PCB stock coated with positive photoresist.
 > 3) Cut stock to size if required.
 > 4) Contact print artwork onto PCB stock with UV source
 > 5) Develop board with sodium metasilicate solution (easier to use than
NaOH).
 > 6) Wash board
 > 7) Etch with ammonium persulphate solution.  This is far nicer to work
with
 > than ferric chloride.
 > 8) Wash board
 > 9) Drill (unless SMD ;-)
 > 10) When ready to solder, remove remaining photoresist with acetone.  (It
 > protects the board in the meantime)
 > 11) - optional - flux and tin traces or use humungously expensive tinning
 > compound ;-)
 > 12) Assemble and solder
 > 13) Clean off flux residues
 > 14) Step back and admire your work :)
 >
 > Exposure, developing and etching can easily be done in under half an hour.
 >
 > One very important tip that I received from a member of this list (think
it
 > was Dan Mccauley) is: remember to put plenty of test points on your
 > artwork, especially if this is a prototype!
 >
 > Contact me off-list if you want to know any specifics, like how to make a
 > UV exposure unit, etc.
 >
 > Cheers
 >
 > M
 >
 > --
 > Matthew Smith
 > Kadina Business Consultancy
 > South Australia
 > http://www.kbc-dot-net.au
 >
 >
 >