--===============1886678059== Content-Type: text/plain; charset="windows-1250" Content-Transfer-Encoding: 7bit In light of a few of the comments about the old-fashionedness and impracticality and expense of toner transfer pcb fab I have to speak up. I use toner-transfer all the time, and I can go from artwork to finished single-sided board in an hour or two (two-hour turnaround, not tooling costs). I regiularly use 12mil traces and 20-25mil trace spacing. I spoil perhaps 1 board in 15 or 20. I was looking to see if there was a picture on one of my boards on the web and found one at http://www.buildyouridea.com/hardware/arcsin/fab_c/fab_c.html. The quality of this board is not particularly good, but it'll give you an idea. It's also a double-sided board which was cnc-drilled, so it took a bit longer than 2 hours to complete. The tools I use are coated paper from Kinko's (or many other places) at about 5 cents a sheet, A block of aluminum about 1 inch thick and 1 foot square, A piece of particle board about the same size, A rubber roller made out of part of a silicone rubber fusing roller from an old copy machine, a couple of household irons(one would actually be adequate), some scotch tape, a scotchbrite pad, a bit of dish soap, and a few sheets of scratch paper. The big problem with iron-on toner transfer is that it's impossible to get consistent results trying to fuse the toner with the iron. The iron is almost (but not quite) flat; the pcb stock is almost (but not quite) flat. The iron has (semi) sharp edges; the pcb stock has sharp edges. The thickness of the toner to be transferred is only a few thousandths of an inch thick, and will also lose its shape when hot and under very much pressure. The perfect setup for failure. Here's how I do it (for a single-sided board. A double-sided board is just a bit (but not much) more complicated): -Set the particle board on the kitchen island. Set the aluminum on the particle board. Set both irons on the aluminum and turn them on to begin heating up the aluminum. -Clean the board stock with the scotchbrite pad and dish soap; rinse thorougly and dry completely. -Tape the printed artwork to the board (just at the very corners). -Check to see if the aluminum is up to temp (I spit on my finger and touch it - if the spit instantly boils away, then it's hot enough. -Remove the irons and place a piece of scratch paper and then the pcb-artwork sandwich on the aluminum ARTWORK DOWN. Place a piece of scratch paper on top of the pile. Give the sandwich 15 seconds or so to heat up and then roll the back of the pcb with the rubber roller. Be careful not to slide the sandwich around while rolling it. This bonds the artork to the pcb enough to hold it in place. (Notice that you're always rolling on scratch paper - never directly on the PCB or the artwork.) -Flip the sandwich over and roll over the back of the artwork (over the scratchpaper covering the back of the artwork, actually) , being careful not to slide it around and being careful to roll out clear to the edge of the artwork just as thoroughly as in the center. This takes about a minute or a minute and a half. -Remove the board from the aluminum and immediately place it under a gently running cold water tap - PAPER SIDE UP. Let the paper soak for 5 minutes or so. The paper will become mushy and will peel easily away from the toner. Rub off any paper remnants with your finger. I use a homemade etchant tank that's about 1 1/2 inches thick, about 8 inches high, and about 12 inches long - made out of window glass and silicone. I have an aquarium aeratiion stone in the bottom and a small aquarium air pump for agitation. It takes about 15 minutes to etch a board (or a load of boards). I use FeCl. For me the hassle is more than worth it. I don't even bother breadboarding much of the time since I can do several iterations of a board in the course of a day if it need to. And the out-of-pocket cost is almost nothing. Old-fashioned, yes. I guess I'm just an old-fashioned kind of guy. Bill K. -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf Of Martin Klingensmith Sent: Sunday, July 09, 2006 5:35 PM To: Microcontroller discussion list - Public. Subject: Re: [EE] PCB via toner transfer method I lucked out having some old inkjet photo paper from the first inkjet I had, that worked really well. The toner transfer method can work pretty well if you are patient. It may not transfer the first few times. I had to use a lot of heat and a lot of pressure. The etched board turned out pretty good. The real deal-maker for me would be a homemade solder mask that acted as a solder mask, not just a film that looks like one. -- Martin K Russell McMahon wrote: >Yet another PCB toner transfer page. >But this man says his version works very well - which is not what all >report. >His results certainly look very good. > > > http://www.5bears.com/pcb.htm > >His says that his main secret is the use of > > Jet Print Multi-Project Photo Paper, 07033-0. > Jet Print color codes their inkjet photo papers... > look for the stuff with the green band. > About $0.75 per sheet here in Texas. > >Other photo papers may work equally well - BUT the search for one that >do can be time consuming. Some people have reported good results with >glossy magazine pages. YMWV. > >Others suggest that the use of a temperature controlled laminator >rather than a household iron also greatly improves repeatability. >He uses Ferric Chloride etchant. > > > RM > >________________ > > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.9.10/383 - Release Date: 7/7/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.9.10/384 - Release Date: 7/10/2006 --===============1886678059== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --===============1886678059==--