Laser Printed Circuit board

Brent Dowell

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Not sure this is worthy of being in the 'Showcase', but it's my first real useful project I've made with my little laser.

Just for a refresher, here is my laser. It came with a 500mw laser on it, but I upgraded to a 2.8w diode model.
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The basic method is to paint the pcb, and use the laser to burn off the paint where you don't want the copper to be. Once the paint is burned off, then you remove the copper with ferric chloride.

I've got a little wifi module I want to hook it up on a breadboard. The problem is the module is not really breadboard friendly, so I drew up a little breakout board in Inkscape.

It's a black and white bitmap, that I run though a program that converts it to G-code to do the etching.
esp01_ver3.png


Here is the PCB after lasering, and a light brushing to get rid of the paint residue
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Here it is after I removed the copper and drilled the holes with the header and pins that I'll be soldering to the board.
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And After I removed the paint with a little acetone and put the components in place.
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All that's left is to solder it up.
 
Well, Had a slight design flaw. Falls into the measure twice, cut once category. The board ended up covering all of the holes in the breadboard!

Time to see how small I can make the traces now.

Not a bad thing, It's all about the experimentation.
 
If you're looking for software, check out DipTrace. For the things you're doing, the software is free. It is by far the easiest to use software out there for PCB design, but despite that it's very good. Part of what I do for my business is design guitar effects pedals and this is what I use. Of course I have the "Standard" paid version, but the free version is exactly the same except you're limited to the number of pins and layers (500 pins, 2 layers...PLENTY for most hobbyiest uses) and only for non-profit use. If you download it and need help, I'll be glad to help too. Standard Gerber file output is actually GCode of sorts (very similar, but different :) ), and there are some science projects out there for converting it actual GCode a CNC mill can use...and maybe there's something for a laser. I don't know. Of course, you could always just print to PDF and work as you currently are. You can also export to DXF.

Here's one hint that could save you some time on larger boards, and may actually results in cleaner etching. You don't have to remove all of the excess copper. Just etch around the traces leaving some reasonable clearance. .015" perhaps, or however much you want.

I haven't heard of someone using a laser to do this. It's essentially fancy photo-etching process. Neat idea! :)
 
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I was able to trim it down with a dremel to fit, but I'm burning a new version right now. Be interesting to see how well the smaller traces will work.
 
Updated model. Need to trim off the excess board, but I'm suprised these tiny traces stayed on.

Will have to see if it works.

This is getting kind of fun.

2015-09-03 (3).jpg
 
I see a bit of copper "fuzz" in the lower left, do you think that is due to your etch or your mask?

The only way I've tried something like this is the iron on laser jet mask ala: http://www.instructables.com/id/PCB-etching-using-laser-printer/ - not exactly how I did it but pretty close. If the ink transferred cleanly it was a really crisp mask, the ink didn't always transfer cleanly of course :rolleyes:

I think it's because even though the laser burns the paint off, there is still a bit of a residue left behind. With the Ferric Chloride, it was taking a very long time to etch, so I'm chalking it up to impatience and the residue.

I just did another one with some Copper Chloride in Aqueous Hydrochloric Acid Solution. Took just a couple minutes and I think did a better job of etching through the residue.
 
It might just be the photo, but it looks like you may have a good number of potential shorts on that board from incomplete etching. Just something I noticed. Don't want to see you blow anything up. You can always just get in there with an X-Acto blade and cut/scrape away any copper you don't want. Your method seems to work surprisingly well, though.
 
Thanks John! I'll take a closer look. This is really my first time doing those. I figure I'll do some continuity and resistance checks on it first.

Like anything new, I'm sure I'll have some spectacular failures. This last one I'm really not so sure about. I think I might shrink the pads just a bit and make the traces just a half a hair wider.

I'm not sure my soldering skills are good enough for the little pad in the lower left.
 
Thanks John! I'll take a closer look. This is really my first time doing those. I figure I'll do some continuity and resistance checks on it first.

Like anything new, I'm sure I'll have some spectacular failures. This last one I'm really not so sure about. I think I might shrink the pads just a bit and make the traces just a half a hair wider.

I'm not sure my soldering skills are good enough for the little pad in the lower left.

If you want, you can look up my name and "Soldering" on YouTube. I have a pretty long series on it...I think I called it the world's most boring videos. LOL. Anyhow, it's more geared towards what you might do for guitar/effects electronics, but 95% of it is just good, solid soldering technique. I'd post it here but I don't really want to spam the forum, even though none of the videos are monetized. I just want to help if I can.
 
If you want, you can look up my name and "Soldering" on YouTube. I have a pretty long series on it...I think I called it the world's most boring videos. LOL. Anyhow, it's more geared towards what you might do for guitar/effects electronics, but 95% of it is just good, solid soldering technique. I'd post it here but I don't really want to spam the forum, even though none of the videos are monetized. I just want to help if I can.

Thanks John, I will do that. Just in time too. I'm getting ready to solder this one up.

I think I'll do some QC checks on it first though.


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Dangit John. I'm easily influenced when it comes to hobbies and I just happen to play guitar and have a guitar I've got to solder up one these day...

Those videos will be a huge help.

Thanks!
 
Dangit John. I'm easily influenced when it comes to hobbies and I just happen to play guitar and have a guitar I've got to solder up one these day...

Those videos will be a huge help.

Thanks!

I apologize in advance for the $100 dollars you're going to spend on an FX888D and tips. Let me know if you need a recommendation where to buy from and exactly what tips to get. :)
 
The new one is done and seems to actually work.

The trick was since it was a single sided board and I wanted the header on one side and pins on the other.

I soldered the header on normally, i.e. with the pins for it going through the board to the copper side.

The pins I soldered on backwards with the little plastic thing starting out away from the board. I soldered the pins to the board, then pushed the plastic spacer down to the solder joints.

Not pretty but it works!

20150903_163608.jpg20150903_163643.jpg
 
If you want, you can look up my name and "Soldering" on YouTube. I have a pretty long series on it...I think I called it the world's most boring videos. LOL. Anyhow, it's more geared towards what you might do for guitar/effects electronics, but 95% of it is just good, solid soldering technique. I'd post it here but I don't really want to spam the forum, even though none of the videos are monetized. I just want to help if I can.

John, I'm so glad I checked back in on this thread ... and that I've known of you on here and SMC for years. You've just given me some awesome late night youtube viewing... thank you!

And to spare some searching for the rest of the folks, here's john's soldering playlist:

https://www.youtube.com/playlist?list=PLgJuY2mH_KJNmpqizft5MwuA3H2jZXzdm
 
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