I'm new to electronics was thinking about creating my own PCBs firstly because I can't be bothered to wire all the connections to a circuit, and secondly I can put components closer together thereby saving space. TBH, I've only got about 3 - 4 circuits that I want to make, at the moment, but even the simple one has lots of connections between IC's and components. With a home made PCB I only have to drill holes and solder parts (I think.). A few questions I would like to know: - Is it dangerous to use the chemicals for the etching? - Are PCBs made this way reliable? - Is it worth the hassle?
Since your new to electronics, I would avoid this way for now. The best way to do things is to wire up the circuit on a breadboard. Test it out first.
Assuming that I've already used a bread board to test my circuit. Assume that I've wired up the circuit on a strip board. Further assume that I now want to to create one board with 6 versions of the same circuit on. (Look here incase you are curious.) The idea of doing all that soldering and wire stripping puts me off.
1: depends... drinking it isn't a cure for something, if you know what I mean, spilling it at things might stain.. and it can damage you'r skin if you get this stuff on you'r hands over longer periods.. if you get it on you, just wash it off... some might react on it more than others, but i hvare put my hands in that stuff many times and i'm still alive... 2: defeneatly more realible than breadboards if made correctly.. 3: depends... if you find this interesting, like to have nice and professional looking, then yes, have money to spend, patience and equipment, then it's worth it...
You could just buy a kit which involves a sheet with PCB/Copper laminate, the etching stuff and a permanent marker. You just mark out where you want the tracks to go and put the thing in the etchant. Then you drill holes. It's quite an easy way of doing it, and you don't have to mess around with wires, afterward, so your circuits look cleaner. If you're like me, however, you'll detect a couple of mistakes once the PCB is etching, which means you will have to add some wires afterward... I would only recommend this if you are making a large circuit. Small circuits are much easier made on those cards with all the holes in them. ("Experiment boards") I bought an etching kit a while ago, but I have used experiment boards for nearly all my circuits, as I find it much easier. You can make tracks of solder, you know.
It depends on how accurate you need the PCB to be. I mean - if all the traces will be small enough to be drawn with a marker - then hell go for it! But once you get into the world of drawing up the PCB then printing it out and using the toner transfer method to put the toner on the pcb - and then etching it - you're probabaly better off just soldering. I'm a perfectionist so all my boards are etched - but that's just me.
I won't reccomend what Bard just said. It sure is nice when you're wiring to LEDs or something, but, really. How good is your drawing? Remember using a marker would make big and _wide_ traces. Check out the Mod Guides forum for Acrimonious' and mine guides on DIY PCB etching
nleahcim: I drew my last circuit in photoshop first anyway so that I knew beforehand how I'm was going to wire. To me it's the size and lack of wires that really attracts me to making a PCB.
Are there any do's and don'ts when it comes to routing? I've noticed that there are hardley any right angled routes, instead there seems to always be a 45degree routes. Also, using programs like ExpressPCB, what's the smallest route thickness that I can reasonably use? Is it safe/normal to route between pin pads? Sooo much to learn.
From memory 45 Degree angles on tracks are to stop EMI and impedance increase at the corner. If your making a 'slow speed' board and its just for yourself I wouldnt worry. With track width you have to be aware of what method is used to produce the PCB. If you are doing it yourself with a chemical etchant then make them as big as possible, or your gonna suffer from several track breaks. If your getting them professionally done then the 0.25mm is probably the smallest I would go unless PCB size was an issue. Also remember to make current carring tracks (power etc) larger, this means the positive line as well as the 0V line.
about going between pads - I avoid it - but sometimes you gotta do what you gotta do. Depends on the space between the pads. But yes - you can. If you are etching it yourself you probably want to avoid this - especially the first time you do it. Now I don't know about this drawing your board in photoshop thing. I draw all of mine with eagle pcb. It was a bit of a pain to learn how to use it (ok more than a bit) and I'm still learning - but it is pretty useful. Have you looked into how to transfer the image to the copper board? I use the iron on transfer method - and it has produced some mighty nice boards - but it is a bit of a pain. About right angle traces - I have used them before. Even in some fairly high speed boards (like the traces for a 100 bt ethernet connection) without problems - but you do want to avoid using them. Round traces look seriously crazy. I use them whenever I can! (just cause they look cool) Anyways good luck and have fun!
Keke. What I meant was that as part of planning the physical layout I pre-draw how I'm going to wire everything anyway, so I might as well use that time and draw in something like ExpressPCB (Or Eagle, but I agree that it'll take time to learn) instead of Photoshop. I'll will try to avoid routing between pads. However, there are situations where the output of one IC is on the other side to where its corresponding input into another IC is. In these situations I find it hard to route because Vcc and Vdd get in the way. The only way I can think of solving this is to use double sided board.
if you want to make tracec between the PC pins you should go for photoresist laminate... there you transfer the imagne using UV light and a overhead transparancy... it id difficult to get everything right, and the equipment is a little bit more expensive (the laminate with a photocoat is... you don't NEED a UV source.. use the sun... however, you don't have as much controll when using sunlight... and it's impossible if there is cloudy ) but it's way better when you get things right... for circuits not requiering that degree of accurancy the photopaper-ironing-method is great, and CHEAP... as for that with getting voltage to pins... remember that it's wery simple to put tracks between the legs of resistors, diodes and such... if you don't have any resistors, you just put in a 0ohm resistor (wire)... 0ohm resistors looks nicer though.. using doublesided boards is NOT recomended for a beginner... it's difficult to get things right, especially for a beginner...
Ok, I know this is off topic, but take a look at this: http://international1.farnell.com/Search/level_5.jhtml?PRODID=51199&SKUID=49138. That's right, 0 ohm resistors . I'm going to order 50 of them tomorrow .
