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Guest pdieguez

Making PCBs

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Hello guysI'm onto making a few FSBUS cards but I'm really not successful in making the PCB... I've tried drawing the card directly into the copper and then taking it to the FeCl, as well as printing the circuit on a glossy paper and then using clothing iron to pass the drawing to the copper, but none of them were successful.... I don't know if the papers that I used were crappy but, with the first paper, I got the circuit with lots of blur.. With the second paper, the circuit was very sharp, but a lot of the drawing stayed on the paper...Do you guys have any clues on how to make good PCBs without muuuuch trouble??Thanks a lotPaulo

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Hi Paulo>I'm onto making a few FSBUS cards but I'm really not>successful in making the PCB... I've tried drawing the card>directly into the copper and then taking it to the FeCl, as>well as printing the circuit on a glossy paper and then using>clothing iron to pass the drawing to the copper, but none of>them were successful.... I don't know if the papers that I>used were crappy but, with the first paper, I got the circuit>with lots of blur.. With the second paper, the circuit was>very sharp, but a lot of the drawing stayed on the paper...>Do you guys have any clues on how to make good PCBs without>muuuuch trouble??It takes some practice to get good results from TT (toner transfer).There are differences in toner, printers, and paper.Then you have variables like iron temperature, the pressure you use, and how long you iron it.For the paper: I use paper from an old electronics catalog, generally all glossy magazine/catalogue papers should work.Also make sure that the copper surface is clean. No fat/grease (like when touching it) should be on it. Everything between the copper and the toner can cause the toner not to stick. (think dust particles)I'm using an old HP Laserjet IIIP, I iron for maybe one minute with the second hightest setting and use a moderate amount of pressure.With a too high temperature, the toner starts to "cook", ie. I get small bubbles. With too much pressure, the traces get flattened, sometimes merging with neighbors.Don't give up when your first (or second) try doesn't come out well. It takes some practice, experimenting with parameters,...For more info, google for "toner transfer".There's also a mailinglist where TT is often discussed:http://groups.yahoo.com/group/Homebrew_PCBs/Manuel

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I managed to avoid the problem of toner transfer by buying a UV resist spray, spraying that onto the board, printing the track layout onto tracing paper and exposing it to a UV light. You can buy these cheaply enough (I gather in the uk for between

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Hi. I have made all of the boards for FSBUS. It is relatively easy to do. Buy the positive pre-sensitized PC boards, and a bottle of positive type developer concentrate. You will also need a contact frame or a piece of glass that can be waited down and a flourescent fixture. There are 1:1 board pictures on the FSBUS site. Print these onto clear film using your ink jet printer. Make sure the clear film is for an inkjet. Now it is just a matter of exposing the board with the layout on top. (usually about 7 minutes with a flourescent light, or 2 minutes with a blacklight fixture.)All of the above items can be bought at www.oselectronics.com, please note that they have a 2-3 week turnaround time. I have also bought all of the parts for the boards. Mainly from www.jameco.com and www.mouser.com. You will also need some ferric chloride to etch the board after developing it.1. Boards: 2"x4" $3.70 3"x4" 3.50 3"x6" 3.85 6"x9" 7.702. Developer 3.453. Ferric Chloride 3.95 These are prices from Ocean State Electronics (www.oselectronics.com) and are in US dollars jus to give you an idea of the expense. Any questions or further help, I will try to logon each day to assist.

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I had good luck with using Staples brand "Picture Paper" for injet printers. I put this stuff in my HP LaserJet 4L laser printer. Once you get that printed, scrub the surface of the copper with some scotchbright pads or something like artificial steel wool 000 grit. Don't rub hard, just enough to clean any stuff off the board. Once its clean, wash the board in liquid soap and hot water. At this point, only handle the board by the edges. The oils from your hands will dirty it. Once thats cleaned off, clean it again with rubbing alcohol to remove any last bits of oil and water from the surface. Cut out the schematic from the paper and leave about 1/4 inch around it. Place it on the board where you want it to appear. Make sure you leave about at least a 1/2 inch of board around the schematic. You'll trim the board when you're done. Then use a regular clothes iron and turn it on as high as it can go (cotton). When it's hot, iron the schematic for 3-5 minutes pressing hard. Move the iron around slowly so that the holes on the bottom of the iron don't stay in one spot too long. Use the tip of the iron to press down on the different areas as well. Just make sure you get it all hot and allow enough time to make the toner transfer. You'll probably have to try this about 3-8 times before you learn how long, how much pressure, etc. This Staples "Picture Paper" works pretty good and was only about $25 after tax for 100 sheets of 8.5x11. Once you've got it ironed, run it under cold water to allow the toner to cool down. Then fill up a sink with hot water and put the board in it so that the water soaks the paper. After about 15-20 mins, slowly peel off the paper. Some will stay on the board and thats ok. If you start pulling up traces with the paper, that means not enough heat was put on that area to make the toner transfer to the copper and you'll have to try again or the copper was dirty (which is why its so important to get and keep the copper clean). Once you have that big first layer taken off, let it sit for another 10 mins or so. Then take your thumb and rub the remaining paper on the board. You'll feel the paper start to rull up into little rolls and come off the board. Try to do this until the rest of the board is clean. Don't worry about the traces, they won't rub off if you've given them enough heat. Then when theres just a little bit of paper left on the board, use a tooth brush and lightly scrub in circles on the board and it'll pull up that last bit of paper. When you're all done, the traces will look black under water but when the board dries out, the traces will turn a white/bluish color and thats ok. Just as long as theres none on the copper. If the traces seemed that they melted together or spread out, you've put too much heat or had the heat on it too long. This will take some practice but once you get it, it's well worth it. I was happy and made my first board without any issues. You can use acetone to remove the toner once you've etched the board. Then tin the traces, drill it out, and stuff/solder it.If you have any questions, please let me know. I'm not an expert by any means but I'll do my best to answer any questions anyone might have. I spent about a couple days playing around with different papers and stuff and this "Picture Paper" from Staples worked the best.

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I am currently putting a black light exposure box together to expose the positive coated boards. I have some other real world obligations happening right now for the next month, but after that, should be good to go. If everything works out ok and I can get good repeatable results, I'll post some pics.If all works well, I would be willing to provide boards for time and materials. I know how hard it can be to find an affordable supplier.ChuckCYXU

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