Homebrew PCBs

Lurk mode off/
I've used the photo-sensitive method (as recently as a week ago) and the RadioShack kit (a few years back). I haven't used the toner-transfer method yet.

On the RadioShack stuff - the copper needs to be really clean. Use a scouring pad and then wipe the board down with acetone. Don't assume the board is clean because it was in a plastic bag. (The PVC bags do something to the copper surface.) It's got to be clean _and_ smooth for the dry transfers to stick. A regular Sharpie (permanent marker) pen will resist the etchant as long as you let it dry well before etching.

Getting traces with rough edges (assuming the original artwork/pattern is smooth) makes me think of two causes. One, the transfers or ink wasn't put down completely or the board wasn't smooth or clean enough to let it stick. And two, the etching probably was done at room temperature. If you heat the etchant (ferrous chloride at RadioShack) to about 100F it will etch faster, which allows less time for it to sneak under the transfer or resist layer and make rough edges on your traces. (I usually put the etching tray in a larger tray of hot tap water to keep the etchant warm. Some put it in the microwave for 15 seconds or so - at their own risk.)

Personally, I have used MG Chemicals positive sensitized PCB system and it has worked well for small boards (3 inches by 6 inches, single sided). I still plan to try the toner transfer when I get a chance.

For double sided DIY boards, some align the artwork top and bottom with tape and then apply the pattern (either toner transfer, photo, etc). Some drill the mounting holes first and then use them to align the patterns top and bottom. In either case, you have to be able to make a reliable pattern in the copper first.

Good luck!
Paul

----- Original Message ----
From: Steven Phellps <scp2000@...>
To: Homebrew_PCBs@yahoogroups.com
Sent: Tuesday, November 7, 2006 3:16:31 PM
Subject: Re: [Homebrew_PCBs] easy PCB









  


    
            

Hi All,



Could someone give me a few pointers.  This I am sure has been discussed but 

I am not sure where to look for the answer so I thought I'd ask.



I tried to build my own PCB with the radio shack kit but the traces are 

terrible.  They aren't smooth, they are jagged.  The traces are thick then 

too thin.  I used a sharpie, didn't work well.  Used the radio shack black 

traces that you press on to the copper clad board.  Very cumbersome and 

results weren't good.



Double sided was even worse.



What is a simple way to make my own double-side PCB ... even a single to 

start is good.  Where do I find a small drill bit?  Mine are too thick and 

the holes are too big that the DIP sockets don't fit properly.  Is there 

freeware to draw a circuit board, print on something to transfer to a copper 

clad board?  Or is there something better than chemical etching with the 

radio shack stuff?



I would like something inexpensive. .. guess the radio shack stuff is pretty 

cheap and easy to purchase without waiting days for the mail.  I've a inkjet 

HP, epson printer.  An old(very old) HP fax machine.  Toner seems to be 

expensive.  I've read some ppl speak of photo etching.  How complex is that? 

  I don't need a really professionally done PCB but something better than 

what I've been using from radio shack(press on traces, sharpie markers etc).



Any suggestions are most welcomed

Steve



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