First let me say I'm not disagreeing with Andrew, his points are good, quite valid, and yet he has made so many good points in one thread it is easier to just reply to his with my take on it, since I do etch some boards myself. I'm not saying he's wrong at all, he just covered so many important factors it was easier to express my take in a reply to his post.
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Originally Posted by AndrewFischer /img/forum/go_quote.gif
Here is why I don't:
The savings aren't enough to make it worth the hassle.
The start up expense. To do it right, I'd need to spend a couple of hundred dollars plus get a decent laser printer.
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It is true you can't realize a savings after the first couple boards, but startup expense has a lot to do with how many of the prerequisite tools/supplies/etc, you have. Given someone who already owns some basic *tools* like a laser printer and a drill press, it ends up being substantially cheaper over the long run to etch your own. To give you an example, I bought several linear feet of copper clad on ebay and a pound of ferric chloride (dry) at MPJA for under $30 total, delivered, and will be able to make over 2 dozen boards with only significant remaining expenses being a small % of the cost of laser toner and maybe 10 sheets of photopaper, maybe a buck or two more if I happened to break a drill bit and about $3 worth of acetone just because it takes off laser toner so easily instead of scrubbing.
I didn't have to spend anywhere near $200 to start, may not have spent $200 total since I first started etching and have good stock waiting for many future projects. If I "had" to, I could even buy the drill press and laser printer plus all supplies necessary for under $200. Then I (would if I didn't already) have a drill press and laser printer, two things even more useful than being able to etch your own boards, IMO. Anyway, a basic entry level set of expenses could include a $5 bottle of etchant (Radio Shack, or several places online sell liquid or dry to mix your own), about $2-3 per 4x5" copper clad at surplus 'sites (works fine, no reason to spend obscene amounts at Digikey/etc, but later buying in larger quantities it gets even cheaper), a spare plastic tub just large enough you don't need a ton of etchant to cover the board (free, or maybe $2 at some discount store if someone really doesn't have a plastic tub (?).
On some cost figures I've left out shipping charges, but it's partially because pre-planning can allow adding items to other orders and items like ferric chloride or a plastic tub are usually available locally. I've left out a handful of paper towels and a little water, an old retired scotchbrite scrub sponge, etc - misc low-cost items commonly found in any home.
Some people will claim it ought to be heated, or it ought to have bubbles, or agitated, many things that are not necessary just so they can speed up the etching process a little. These are nice
luxuries but not at all necessary to achieve a good result, basically the difference is it takes 10-25 minutes instead of 5, but what was the other alternative? Waiting days to get a board you order somewhere. If someone doesn't have anything they can do for 10 extra minutes wait-time, what was the hurry? Multi-tasking rules.
It is true a laser printer is a large initial expense. It might be enough to sway someone away, but a laser printer is such a wonderful computer toy to have, just get one! All kidding aside, my opinion is it's one of those modern conveniences worth owning, just for it's obvious intended purpose, nevermind etching circuit boards.
It does not need to be even slightly "good" quality printer, any ancient 300 DPI printer is fine so long as it works as it was designed to and the cartridge isn't shot. I was using an old (8-10 years maybe?) HP Laserjet III that had been refilled with bulk copy machine toner and had over 500K pages on it, but it died last year so I started using my 2nd oldest (now oldest) printer, a Lexmark/IBM 4039. It can't keep toner adhering to the shiney side of "glossy" photo paper, so with it I have to use semi-gloss or flip the paper over (so long as it's coated on the back too).
I've used a high-end color laser, and a cheapo $40 AR Samsung 2010 B&W laser, all have done an acceptible job but I tend to use the older printers because laser fusers used to get hotter than current models do, in many cases allowing for cheap bulk toner refills which make it very cheap to print (anything, but especially pages with a lot of toner like an etching pattern).
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| I don't own a drill press. Holes can be made with a dremel but they aren't as good. |
I can drill fine holes with a dremel, but don't as the problem is the HSS bits dull too quickly and the carbide bits are too brittle and break because I don't have a dremel press stand and won't buy one because I have a drill press. Certainly the cost of a drill press is another deterrent, but a drill press is another one of those vital, must-have toys even if you aren't making your own PCBs.
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| I don't have the proper tools to cut the boards up. I got yelled at the last time I used the paper cutter at work. Besides the results are kinda crappy. |
Generally I buy based on the width desired so there's often only one cut needed. A miter saw is useful, but I've cut with a hacksaw and sabre saw as well, it's not so different from cutting any other thin piece of wood accurately. That's not some peoples' cup-of-tea, I'll grant that some are more likely to be experienced in similar hobbies or work skills carried over towards useful tools and experience with certain aspects of making boards. If a cut isn't straight but close, there are lots of ways to true it some like a router or belt sander or table saw or whatever. Suppose it's off by 1mm in one dimension though, that may not be critical. At worst you just throw it out, all in all the cost of a blank piece of copper clad is low compared to cost of a whole project.
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| I'm not sure if I could get a double sided board to line up. I'm sure it can be done, I just doubt my skill level. Mess up once or twice and it would be cheaper to send the board out. |
It's not expensive to make mistakes, usually. Suppose you get 4 patterns out of $1 worth of photopaper + toner, used $0.80 worth of etchant on a board, and the board cost $2. The worst possible mistake late in the process would cause you to scrap a board, at a loss of $3.05. Usually, if there is a mistake or alignment problem you can just stop at that point in the process and the board isn't a loss, you may only have to remove toner and apply one of the remaining 3 patterns you made on the same piece of photopaper.
It does take practice, method to align two sides, and at least a printer + software that outputs correct aspect ratio or "close enough". I would suggest anyone looking to get into etching, start out with easy single-sided projects then progress to more complex when they feel ready.
I should mention that I don't try to etch very very fine traces, but a large part of why is that there are no projects here that require it, save for a high pin density DAC or something like that.
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| You don't get solder mask, silk screen or plating with the basic toner transfer boards. DIY doesn't require these features, but I like to have them. |
If you want to plate, you can get cold tinning solution or use a tinning flux and put the board in (an old toaster oven, etc) to bake it on. That improves solderability, but a topcoat of lacquer or conformal coating could be used. It does slightly add to the cost per board, but for one-off projects the board cost is still substantially lower than ordering it anywhere. Plus, it's not necessarily that you're creating a final masterpiece $300 amp with a DIY etching, it could be a test circuit or something you never glance at ever again, what it looked like just didn't matter.
Silkscreen is useful as an aid in parts ID and placement when building, but frankly I never felt it was missing when I didn't have it. Depends on the density of the board (parts as well) if you had a ton of tiny surface mount parts it is of greater benefit to ID parts and reference a schematic than on most of the larger scale parts we're using for headamps.
I think it can be said that you don't have to choose always etching or always ordering boards, each can have their place. I can say that it's a nice convenience that if you want a board to use quick, an hour after you have a pattern to print you can already have a board finished after a few boards practice so your speed at doing it increases. This is especially true with drilling, if you have good hand-eye coordination it goes pretty quickly. EDIT: I mean quickly on a drill press. Unless you have HSS bits, typical carbide PCB bits may break too easily to go fast with a dremel or hand drill (and still breakage rate might be high even if you take you time unless using oversized bits).
Some people just don't want to, and I can accept that. There are a lot of things those people do in (life) that I might not want to do instead. For the cosmetic effect alone, I would encourage buying professionally made boards for any higher-end project, because that is obviously very important to some people (if not all) on *some* projects, but not all projects can be classified as such. I suppose my conclusion is that it's not something viable to make only one or two boards *ever*, but over time it can be a good suppliment to an electronics related hobby(s). You're never compelled to etch any particular board, can pick and choose when to do so.
