Quick Etching Idea

[ericgibbs]

hi 3V0,

I am slightly of topic, but knowing your teaching interests I thought this link would be useful, especially the section covering 'tin whiskering'

BTW: Farnell do have lots of free techno publications.

EDIT: Woops, had to delete that link, it brought up my emailing.

I'll try to repost later.!

 

[Cotowar]

I've never made my own board before, so if you guys could critique my process before I drop money on it that would be awesome. Here's what I'm planning on doing.

Design the layout with EAGLE Cadsoft or some other schematic CAD program.

Print the schematic to Photo paper with a laser printer.

Iron the schematic to the blank PCB with the toner side down. Fill in any missing areas with several passes of a sharpie marker.

Etch the surplus copper from the surface with AP solution, and laying the board in a plastic container and gently rocking it around.

Applying the green film to the board by ironing the blank piece to the board.

Drilling the connection holes with a dremmel or drill press.

Applying Silk screen with the white film just like the green film.

Soldering my components to the board.

Plug it in and see if it works.

Is this right? I was also wondering how I would know when the board was done etching?

 

[3v0]

Eagle is an excellent choice but it is not a cake walk. Use Eagle to draw the schematic prior to routing the board. Eagle will make sure your schematic and PCB are the same circuit. There are some DRC settings that you should change and we can talk about that when you get there. If Eagle is too difficult you can use other packages but it is a trade-off IMHO.

As long as you are buying the green and white foil spend another $15 for 10 sheets of the transfer paper. It is worth twice that and should last you a year or more. You only use a piece just a bit larger then the PCB you are making so it goes a long ways. No guessing with this stuff. When it gets wet the toner falls off. I made a label once by spraying a few coats of clear acrylic over the toner and then wetting the paper. The paper released the toner and the acrylic in a single fragile sheet. Not recommend but it was a fun experiment.

If possible beg, borrow, or steal a laminator.

Some people do a good job without either but having them makes the process nearly fool proof.

 

[pc88]

I've never made my own board before, so if you guys could critique my process before I drop money on it that would be awesome. Here's what I'm planning on doing.

Design the layout with EAGLE Cadsoft or some other schematic CAD program.

Print the schematic to Photo paper with a laser printer.

Iron the schematic to the blank PCB with the toner side down. Fill in any missing areas with several passes of a sharpie marker.

Etch the surplus copper from the surface with AP solution, and laying the board in a plastic container and gently rocking it around.

Applying the green film to the board by ironing the blank piece to the board.

Drilling the connection holes with a dremmel or drill press.

Applying Silk screen with the white film just like the green film.

Soldering my components to the board.

Plug it in and see if it works.

Is this right? I was also wondering how I would know when the board was done etching?

You want to apply the green film BEFORE etching the board. The green film is used to help seal the toner so that's it's more resistant to the etchant.

 

[3v0]

You want to apply the green film BEFORE etching the board. The green film is used to help seal the toner so that's it's more resistant to the etchant.

I missed that. The green film is not to color the board. As pc88 said it is to seal (reinforce) the toner prior to etching.

 

[Cotowar]

I missed that. The green film is not to color the board. As pc88 said it is to seal (reinforce) the toner prior to etching.

Thanks For the help. Oh, and I can get my hands on a laminator easy enough.

And that idea about the acryllic for a label is pretty sweet. I was thinking about doing something similar to that myself actually, but didn't know how well the acryllic would hold.

Oh, and right now I have a desktop computer solely for my projects (ie programs, CAD, circuit design, data sheet storage, etc.). The only thing is this beast is so old it has a "Designed for Windows 95" sticker on it. I've been inside it several times tinkering with things, and noticed it has a pentium 2 processor at 400MHz, FSB 100MHz, and 128MB of 168-pin SDRAM at 133MHz. The only reason I'm using it at all is because its available and has a serial port where I can plug in a µC programmer. My page file is almost completely full just running windows XP, and my hard drive sounds like a wood chipper its doing so much. I was wondering if you guys think it would be worth it for me to buy a barebones system off newegg for like $80 and just buy a PCI serial port card. I can salvage the CD drive, the Hard Drive, and the Floppy if needed, as well as all the expansion cards I already have inside the old unit.

Do you guys think it would be worth it to buy a new system or to spend some cash on more RAM for the one I have. Money is extremely tight for me, as I'm paying for college on my own, and I only work 20 hours a week making minimum wage. Just opinions, I really want to have everything ready to go once I start working on this stuff, that way I don't have to put my projects on hold so I can get new equipment.

 

[3v0]

It takes a brave man to run XP on a 400MHz box I would not stick another dime into it.

If you are short on money and in a university town I would see if you could find a unwanted 600MHz or higher box for free. Check dumpsters. We used to have an electronics surplus recycling place where people would dump off old computers after dark. I think they were thinking they would have to pay the place to take them. A few people I knew shoped there after hours and came away with good machnes. The owners did not like it but it was not stealing.

We need to get you into a junebug, it is faster and the serial port is not an issue.

EDIT: If you are using PICs.

3v0