Posts with «etch» label

2-Layered PCB with a Laser? Nah, Toner Transfer

I tried using the laser to remove some spray paint, and... I declare it a dud. Two major factors stymied this process for me for the moment:
  1. I didn't have the right spray paint (matte black) nor the right environment (dry and warm) for the paint I did have. What I did get to stick to the copper had a very uneven surface.
  2. The laser is... finicky. I can't tell if the layers were wildly inconsistent, if the paint behaved differently as it dried, or if maybe the laser had trouble, not liking the cold temperature or moist environment. I never can tell if it's about to give up.
Impatient as usual, I used my regular method: laser printer toner transfer. Determined to make a 2-sided board work, I spent a while aligning corner crop marks and pre-taping the paper with the toner before laminating it to the copper. The toner transfer was spectacular-- just perfect laminating it ten times (5 up, 5 down), but the top-bottom alignment, while close, may not be close enough. At this point it's etched and drilled, but there are still bridges and the misalignment will make assembly an adventure.

Looking at guides online, (especially the tutorial at An Engineer's Life which so many people are linking to today,) it does seem like most people use a photographic process and abandon toner transfer when they go for double-sided and SMD. Before going that route, I want to take toner transfer further though-- I've had such good results so far, the only issue is top-bottom alignment. The biggest sources of alignment error:
  1. Top-bottom alignment of printed out patterns. A light table, some magnets, and tape should do the trick-- I need to see the registration targets better.
  2. The laminator binds and jerks sometimes, which could distort the pattern slightly. It's hard to tell without sending through a test image, but it seems like time to take apart the laminator and see about modding it to separate the rollers a hair.
I'm happy with a slightly lower level of quality with toner transfer because it's a simpler process with fewer (and cheaper) expendables that can also transfer labeling to the top and bottom after etching.
Jeff's Arduino Blog 21 Dec 00:12
etch  pcb  toner transfer  

Birth of an Arduino

Hey look, an Arduino without its clothes on. This one’s just started its journey to becoming the ubiquitous prototyping tool. The image is from [Bunnie's] recent tour of the fab house where Arduino boards are made.

As it says on every true Arduino board, they’re made in Italy. [Bunnie's] trip to the factory happened in Scarmagno, on the outskirts of Torino. The process starts with large sheets of FR4 copper clad material, usually about 1 by 1.5 meters in size. The first task is to send the sheets through a CNC drill. With all of the holes done it’s time for some etch resist; the image above is just after the resist has been applied. A robotic system takes over from here, running the panels through the chemicals which first etch away the copper, then remove the resist and plate the remaining traces. From there it’s off to another machine for solder mask and silk screen.

There are videos of each step available. But our favorite piece is the image at the end that shows a pallet with stacks of completed PCB panels which are headed off to be populated with components.

[via Reddit]


Filed under: arduino hacks
Hack a Day 15 Aug 12:01
arduino  arduino hacks  circuit board  drill  etch  fab house  fr4  pcb  

MinimalDuino 107 Pattern

After submitting the 105c version to the DorkbotPDX PCB order, I mentioned I'd make one at home, but the traces looked so thin on paper and I didn't like the routing of gnd to the crystal area, so I made a few changes to optimize it for toner transfer and home etching.

Here's a shared folder with the updated, v107 EAGLE files and a 600dpi jpeg for toner transfer. See the low res at right, or click for higher res; get the full res jpeg here.
Jeff's Arduino Blog 16 May 21:52
etch  minimalduino  toner transfer