Etching my own PCB's a couple questions.

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
A google search for PCB fabricators will bring up several fab houses that will make your boards look like the real thing for a very reasonable price. $50-100 for fast turn small lots if I remember correctly.

Weight that against having to deal (and dispose responsibly) of all the developers and etchants - all really nasty stuff - and it's not worth it in my books.

I've used PCBexpress in the past and they did a really professional job, silkscreen and all.

My 2cents
 
You don't need all that stuff...

I use an icecream tub, and just swirl the liquid around until the etching is done... (5 to 10 minutes) afterwards I put the tub somehwere high and out of reach... the water evaporates and leaves crystals... when I want to use it again, I just add some boiling water and stir the sludge up again...

I think it is rather critical to be able to do some home prototypeing before hitting the factory.... very usefull in spotting errors... And I say that even haveing access to cheaper fabrication (due to labour cost) facilities..
 
Administrator
Joined 2007
Paid Member
Hi Douggie, I have been making boards for years, it's easy. Are you going to draw by hand/transfers or use a CAD program ?

Edit, you ask what is the best kind of acid. You want anhydrous ferric cholride crystals, mix according to the instructions. Store the mix in an old plastic bottle. I read Nordics post, I have visions of him boiling it up on the cooker :) . I tend to use just enough for the job in hand and always use fresh mix, you don't need much by the way. I use a tub like Nordic and float it in a sink with a bit of hot water in, you want the mix warm not to hot, agitate gently all the time, should take about 10 mins.
 
Hi,
Use acid in made a pcb only give you small benefit comparing use a fericlorid and other thing you must understand acid is very bad very carefull with it, the best use fericlorid and use it in warm temperatur 50 to 60 centigrade and use as much as you need if posible use just for one time. no heater just place the liquid under sun..........we have plenty of sun here in Indonesia.
 
Well someone posted a PCB drawing that I'd probably use. Maybe it would be best to just order them though as then I Could have double sided pretty easily. I'd probably get the PCB printed on the clear paper stuff and iron it onto the copper clad board if I did make my own.
 
I etch a board every month or two and have found that I like the method on Tom Gootee's page: http://www.fullnet.com/~tomg/gooteepc.htm#1

For toner-transfer, I've tried magazine paper, photo paper, and transparencies. All of them work, and can be bought locally, but I ended buying some press-n-peel blue and have not looked back. Press-n-peel works great and I highly recommend it. You will always have to go back with a paint pen (better) or a sharpie (passable) and touch up your traces, even with press-n-peel.

For etchant I use the 2 part hydrogen peroxide ($0.77 at wal-mart, 1 part muriatic acid ($4.99/gal) at the local hardware store. It's not the fastest I've used (faster if warmer), but it is inexpensive and available. I try to use a little as possible to get the job done, and I dilute it with a gallon or so of water before disposing of it in the toilet.

It isn't hard at all, but you are going to spend about 20 or 30 bucks the first time (or more depending on how much press-n-peel you buy). If you don't plan on doing many other boards, by all means use a PCB fab shop.

Good luck,
David
 
Yeah I'm not sure how often I would be etching boards. Another thing is getting everything I'd need. I want to get a dremel with the drill press thing for it to drill out the holes and stuff. All this stuff together is going to cost probably 100 bucks or so the first time so I'm not sure its worth it if I'm not going to be making quite a few PCB's
 
Administrator
Joined 2007
Paid Member
Untill I started producing boards using a software package, all my attempts were hand drawn using "Overhead projection" type pens, and transfers for circles and I/C,s. I am not saying it is easy to produce good artwork direct on to the copper this way but the image I have attached is all done this way. The secret is to clean the copper first. I use an "abrasive kitchen pad, you know those green things" and then clean the board with paper towel and isopropanol. I use a low voltage but high speed handheld drill for all holes.
You don't need any expensive gear to get started, it will take practice and you will have failures but it is worth it. And if you fancy using a PCB package on your PC I can recommend www.diptrace.com . It's freeware and excellent.
Regards Karl
 

Attachments

  • imag0191.jpg
    imag0191.jpg
    48.7 KB · Views: 486
Disabled Account
Joined 2007
Dougie085 said:
All this stuff together is going to cost probably 100 bucks or so the first time so I'm not sure its worth it if I'm not going to be making quite a few PCB's


Making your own PC boards is very satisfying. It is addictive.:)

The big benefit is not having to wait for the order to come. Also, as mentioned above, the ability to debug the layout is invaluable. You could do several board revisions in one day.

With not too much practice, you can produce excellent quality work for next to nothing.
 

Attachments

  • im001512.jpg
    im001512.jpg
    94.2 KB · Views: 488
Iain McNeill said:
Weight that against having to deal (and dispose responsibly) of all the developers and etchants - all really nasty stuff - and it's not worth it in my books.


Well the etchant solution can normally be used many times before it is no good. Especially if you use a ground plane on your PCBs then the amount of copper you etch away is less and your solution lasts even longer.

Disposal is not too difficult. It's just a matter of placing it in a plastic container, properly labeled, and bring it over to the hazardous waste center.
 
Administrator
Joined 2007
Paid Member
Hi Douggie, First things first, have you downoaded the tutorial for Diptrace. This will walk you through designing a simple board and circuit. I prefer designing manually rather than using the autorouter, you have more control, and it's quicker for simple designs.
The only way is to have a go.
Do you have a good Inkjet printer ? I use a cheap Epson DX4050 with special transparancies designed for Inkjets. To produce boards this way you need an ultraviolet light of course. (You can make your own). But as I say first things first. I found it helpful to go through the libraries in Diptrace and drag common parts onto screen, res400 cap200rp, that sort of thing and print them out so you can see the physical size of the parts. Its no good using res800 for 1/4 watt resistors as these are huge ? Same with caps.
Just to confuse you, remember when you draw a board freehand you have to mentally reverse or "mirror" the design. An 8pin IC would have pin 1 at the top left on the copper. If you design "freehand" with diptrace direct on the screen you are looking down on the component side, so our IC would have pin 1 at the bottom left. When you print out, don't use the "mirror" facility because if you use a U/V light box you want the "ink" on the transparancy in contact with the copper and this action "reverses the image".
It all sounds horrendous dosn't it. Read and if poss print the relevant parts of the tutorial, put them in a binder and study it.
Have a go drawing at schematic, the circuit not the pcb, something easy, I would say a single 741 opamp as a simple amplifier, 3 resistors, tell you what, if your interested I will take some screen snips running Diptrace so you can get the idea.
Regards Karl
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.