MadModder
The Shop => Electronics & IC Programing => Topic started by: Brass_Machine on March 10, 2010, 09:55:52 AM
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I remember there being a discussion about PCB etching... here is a video I just got the link for...
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Thanks for posting..
Not bad...
A couple of tips for those thinking of doing their own....
I use Ferric Chloride for etching my own boards, but I heat it first in a microwave oven, this and agitating the board results in a board being etched in a lot less time than the demonstrator states...
After the board has been etched and cleaned I use Tin Plating crystals to add a tin plate coating onto the track...aids soldering and protects the copper from tarnishing...
I find the hardest part is drilling the holes...My eyesight isnt as good as it was 20-30 yrs ago :(
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...
I use Ferric Chloride for etching my own boards, but I heat it first in a microwave oven, this and agitating the board results in a board being etched in a lot less time than the demonstrator states...
After the board has been etched and cleaned I use Tin Plating crystals to add a tin plate coating onto the track...aids soldering and protects the copper from tarnishing...
I do the same microwave/agitating bit. Goes much faster.
Tell me more about the tin plating??
Eric
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Eric,
Basically you take tin plating crystals dissolved in hot water ( 50deg C) place the board in the solution and the copper is coated with a layer of tin...Takes up to about three hours depending on the thickness of the plating you want...
Not sure if its available across the pond but I would have thought so from RS or Farnell..
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Eric,
I did a google. Lots of places here in the US.
Wish I could remember what I used back when I did circuit boards. Maybe it'll come to me.
Bernd
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I am currently working on my UV exposure box as we speak!
I have all 95 LEDs hooked up on a board and running of my converted PC PSU 5v supply. My brother in law has built me a nice wooden box with silver foil reflective sides and lid - I picked this up about 30 minutes ago and I`ve just this second finished programming my PIC that runs the timer. I was just checking on here before going into the shop to make a start on hooking it all up!
Thanks for the vid. Excellent! I was tempted to use dilute NaOH for developing and HCl for etching....anyone experience going down this route rather than "developing agent" and Ferric Chloride?
Chris
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I was tempted to use dilute NaOH for developing and HCl for etching....anyone experience going down this route rather than "developing agent" and Ferric Chloride?
Chris
I thought Sodium Hydroxide was the developer....
I use Ferric Chloride for etching..
I prefer to use proven techniques for these sort of things..
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Chris
I've perked up tired FeCl with a bit of HCl ( dilute ! ), but never used it as the etch solution. I would think it may be too aggressive. If you do skinny traces that sneak betwen the pins on DIL etc. It may be that they get undercut and disappear. Particularly if you warm the etch bath.
I agree with Mr. Rudd. Stick with FeCl ...
However, feel free to try it at your expense .. :D and then tell us how you get on for nowt ... :)
Dave BC
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Here's a couple of boards I designed and etched..They are plated and then lacquered to protect even further....
(http://i754.photobucket.com/albums/xx182/Chippiejnr/S8000687Small.jpg)(http://i754.photobucket.com/albums/xx182/Chippiejnr/S8000686Small.jpg)
(http://i754.photobucket.com/albums/xx182/Chippiejnr/S8000685Small.jpg)
(http://i754.photobucket.com/albums/xx182/Chippiejnr/S8000684Small.jpg)
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Nice John! Whats it do?
Eric
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Nice John! Whats it do?
Eric
They were programming interfaces for smartcards for sat tv.....
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I'm fortunate to have a bubble etch tank for etching boards. The etchant, Ferric Chloride, is first heated with a built in heater, the board is then mounted in a holder and submerged vertically. You then switch on a small pump that blows bubbles up past the board (just like a fish tank aeriating block). This washes away etched copper, and speeds up etching time. It is fast, when properly warmed up it etches a board in a few mins. Another advantage is the etchant stays in the tank and can be left in the garage out of the way, so human contact is minimised.
Ken
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I use NaOH (sodium hydroxide/caustic soda/lye) for developing, and ferric chloride for etching. If the board is going to lie flat on the bottom of my etchant tank (aka whatever plastic box I can lay my hands on - usually a food container), I put a bit of plastic rod under the middle of the board, so that one end can be pushed up and down with another bit of plastic rod in see-saw (teeter-totter) fashion every now and again, to agitate the etchant.
Andy
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I am about to try this methoud just got hold of the spindale.
Peter
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Very cool Peter! I expect pictures/videos :thumbup:
Eric
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Hi, I'm a bit late on the posting, but this takes me back to my days working in r&d with a small burglar alarm company, where we made all our own boards until the design was proven out. We used u/v sensitive photo resist, had a photo shop make a positive from our printout, sprayed the etch resist on the board blanks, and put the blanks in a box with a glass face, with the photo positive, done on clear film, over the board e.g. photo between the sun and the resist, and left it in the sun for a minute of two. In california, that was enough u.v. exposure to get a full and clear board, and washed the exposed resist off with just water, if I remember correctly. We usually had four circuits per board, and cut them separate with an old school paper cutter, the big cast iron based ones that give a dead straight line. We drilled out two of the locating holes, put four or five boards in a stack, with steel wire in the holes to keep the boards all lined up, and gang drilled the boards. Once the design was working with the rest of the system, we contracted the boards from a comercial board manufacturer by the many hundreds. The issue to me, is the simplicity of spraying etch resist on the blank pc board, laying a clear sheet with the circuit black on it on the surface of the resist, and clamping it all in a picture frame with a piece of say half inch foam on a board with hinges and a latch, to hold the positive print against the glass, the board against the print, and only about a minute of exposure to the sun, to be through with "setting" the etch resist. I'd have traded a horse for the tinning solution mentioned, we had nothing like that there, thirty years ago. We also didn't have laser printers either.