Build Your Own PCB Milling Machine

mwandel writes "It used to be that one off amateur printed circuit boards were all etched in acid. A lot of companies nowadays use a special form of milling machine to mill them out of solid copper clad circuit boards. This guy Jonathan Westhues built his own PCB milling machine out of various parts, with a laminate trimmer as the milling head. Lots of other neat hacks on his Webpage as well."

Comments

Re:Isn't it a salt?

[Paul Neubauer]

Yes, it is a salt. Copper is more reactive than iron, so the etch works by the chlorine trading iron for copper. The "filings" left after etching are the iron that was freed in the reaction.

Some folks see it anything that 'eats' away at something as being caused by an acid, even if no acid is really involved. Wouldn't it be nice if chemistry was taught? And taught in a way that was effective?

Re:There are easier ways

[Ratso Baggins]

You may be missing the point, he machine's turn-around-time is 1 hour(ish) the best you can get is 1 day from the fab co's. Secondly @$80 a board you will quickly pay for the milling machine, if you have need for it. I like it because @ 1:00am when I'm ready to do the board - I can... and how many things geek are done "because I can"?

Granted it's only double sided - but at that it's wonderful. Wow, no more chemicals! I've always-forever wanted one of these but the pro milling machines are out of my league.

Re:Amateur

[uglomera]

Milling machines are not an overkill or a solution for amateurs, they are a very good solution for inexpensive prototypes or production needed in small-mid volume.

Acid etching produces a functional board, but it simply does not look good, and you can't make 100 boards that are exactly alike. The lines are almost straight, the edges are not perfect, and if you are on a contract to deliver a product, this is not an option. Examples of where a milling machine is one of the best solutions: a university lab where the researchers are under government/industry contract and are supposed to deliver a working prototype or a small business with a military contract (small volume products).

I worked for a startup company for a while, and part of my job was to work on a QuickCircuit milling machine, and that thing had milling bits that were 4 mils thick (comparable to hair). You can hardly reach this precision with acid etching. I also adapted the machine to dice wafers, which replaced the company's practice of using an exactoknife :)

If you are in the IC design business, testing cheaply is of primary importance. You can get a full setup for producing boards for less than $10K. How's that compared to billions of $$$ for setting up an IC production plant? And if you are in the RF design business, you need the precision so that a crappy board does not screw up your high-frequency measurements.

Of course, milling is no option for producing high-volume PCBs with many layers, but don't think that ASUS spent months to design such a board to test their new motherboard design. First they have to verify that design works, which is done with a cheap PCB design, one that would hook up the ICs. Only after that stage can the final PCB design begin.

As long as the Z80 or 68K processors are still in use, simple PCBs will be here, and we need a cheap and fast way to design and make them.