Post by thread:[EE] Etching my first PCB

I etched my first PCB today. It came out very well (considering that it was the first one I did). I used a mix of different techniques which all worked out well for me in the end. To begin, I made a simple design for a quick prototype board for my dsPIC33FJ128GP802. The board itself is very small, just about 1.5" x 2.5" (off the top of my head). I had a large sheet of copper clad board so I had to cut out the small piece that I would be working with. This part was not fun at all. I printed out my design and traced out the rectangle off a corner of the large copper clad board. I then used a utility knife to score the sides of my design. It took a while to get deep enough to snap. Then I used metal shears to cut one edge of the board. This was an unclean cut and damaged part of the large board and slightly warped the copper on my design. No big deal. I then stuck the remaining part of the board into a vice (with paper towel for padding) and snapped the remaining edge. I then sanded the sides with a piece of (metal purpose) sand paper. I was then left with a small rectangle of copper board ready to be used for toner transfer. I used nail polish remover to clean the board. Then I used soap and continued to clean the board. Finally, I took some fine sandpaper and scrubbed the board clean. The board was now ready for toner transfer. >From suggestions from my other thread, I tried a different printer. I used the same paper (staples glossy paper for laser printers) that I had tried before. I set the print quality to the highest setting and configured it to deposit the most amount of toner possible. I then cut out my design and headed over to my clothes iron. I preheated the board by placing a blank sheet of paper of my board and ironing it for about a minute. Then I carefully placed my design onto the copper board. It stuck instantly. I ironed it for about 2 minutes. (60 of those seconds I just left the iron on top and went downstairs to get a snack). I didn't do anything special. I just pressed hard (but not too hard) and went over it with the tip of the iron. I then filled a small sandwich box with water (about body temperature) and dropped my board (with the design paper still stuck on it) into the water. I headed over to my local grocery store to get some groceries for dinner. By the time I came back, the paper was soft enough to peel and rub off with my thumb. Some of the toner smudged, but overall, the quality was pretty good. The toner had definitely stuck well this time. Now for the etching part. I took a small dish washing sponge and cut out a square about 3" x 3" x 0.75". I poured about a table spoon of ferric chloride on the sponge. I put on my vinyl gloves and started lightly wiping the board with the sponge. The copper started to come off instantly and turned the bright-yellow sponge nearly black. I kept wiping for about 2 - 4 minutes and eventually, all of the copper (that was not protected by the toner, of course) came off. This sponge method turned out to be very fast, efficient, clean and easy. Also saved a lot of ferric chloride. I ended up with a very well etched board. It was easy to see when it was finished and the etching solution worked very fast and etched very cleanly. Then I washed the board and inspected it (and admired it). It would have been perfect had the toner not smudged. The etching process itself was very clean and precise. The only trouble was the toner. I need to find a better way to put etchant-resist onto my copper. I then took the almost-finished board downstairs to drill. This part was not fun as well. I drilled about two holes then gave up because all I had was a clunky drill and very brittle drill bits. This drilling part is impossible without a proper drill press. A CNC machine would be ideal (even a crude one would do the job sufficiently). So there ya have it. An almost-finished PCB. Looks like I'll need to find myself a drill press. To all the helped and gave advice, thank you very much. This process turned out to be fun and educational and I leaned a skill that I'm sure I'll find very useful in the future. The whole process took less than an hour and gave very good results. The results would have been perfect if I had a better method to transfer the toner (via laminator and a good printer, maybe) and a CNC machine or at least a drill press. What I was most impressed with was the sponge method of etching. Only a table spoon of ferric chloride was required and none of that heating/agitation nonsense was needed. The process was clean and efficient - no spills, little to clean up afterward. So if there's any of you still pouring the etching solution into a tub and heating/agitating, I highly recommend that you give the sponge method a try. It's awesome! -- [ solarwind ] -- http://solar-blogg.blogspot.com/

4 Items: 1: What was the printer and toner that worked and didn't? 2: For a drill press, I have used Dremel with very good results. I also have a 16.5" Delta drill press with 1/16" - 5/8" chuck, and then a smaller drill size chuck that can be gripped, but wouldn't even think of using that, although the small drill bits with 1/8" shanks can be gripped easily. Get the regular PCB drills with 1/8" shanks and short drill spiral lengths. The long drill bits with same shank diameter as drill size get slight bends, wobble, and eventually break. 3: When making the PCB print image, every hole should have a small size hole etched in the copper. This becomes the equivalent of an accurately located center punch to get the drill started at the right location. The drill will wander to that depression if you get close to the location. 4: For double sided boards, I include a donut at 4 corners, both sides. Pin prick through the paper before ironing on the first side, drill the 4 holes through the board, use pins through the papers and holes to align, and iron on the 2nd side. Have had good results with careful work, but there are limits to the accuracy. Dips with 0.1" spacing should be no problem if there are not traces between the pads. With traces between, probably will scrap some boards, probably would solder wire across for the a few to be made. :) solarwind wrote: {Quote hidden}> I etched my first PCB today. It came out very well (considering that > it was the first one I did). I used a mix of different techniques > which all worked out well for me in the end. > > To begin, I made a simple design for a quick prototype board for my > dsPIC33FJ128GP802. The board itself is very small, just about 1.5" x > 2.5" (off the top of my head). I had a large sheet of copper clad > board so I had to cut out the small piece that I would be working > with. This part was not fun at all. > > I printed out my design and traced out the rectangle off a corner of > the large copper clad board. I then used a utility knife to score the > sides of my design. It took a while to get deep enough to snap. Then I > used metal shears to cut one edge of the board. This was an unclean > cut and damaged part of the large board and slightly warped the copper > on my design. No big deal. I then stuck the remaining part of the > board into a vice (with paper towel for padding) and snapped the > remaining edge. I then sanded the sides with a piece of (metal > purpose) sand paper. I was then left with a small rectangle of copper > board ready to be used for toner transfer. I used nail polish remover > to clean the board. Then I used soap and continued to clean the board. > Finally, I took some fine sandpaper and scrubbed the board clean. The > board was now ready for toner transfer. > > >From suggestions from my other thread, I tried a different printer. I > used the same paper (staples glossy paper for laser printers) that I > had tried before. I set the print quality to the highest setting and > configured it to deposit the most amount of toner possible. I then cut > out my design and headed over to my clothes iron. I preheated the > board by placing a blank sheet of paper of my board and ironing it for > about a minute. Then I carefully placed my design onto the copper > board. It stuck instantly. I ironed it for about 2 minutes. (60 of > those seconds I just left the iron on top and went downstairs to get a > snack). I didn't do anything special. I just pressed hard (but not too > hard) and went over it with the tip of the iron. I then filled a small > sandwich box with water (about body temperature) and dropped my board > (with the design paper still stuck on it) into the water. I headed > over to my local grocery store to get some groceries for dinner. By > the time I came back, the paper was soft enough to peel and rub off > with my thumb. Some of the toner smudged, but overall, the quality was > pretty good. The toner had definitely stuck well this time. > > Now for the etching part. I took a small dish washing sponge and cut > out a square about 3" x 3" x 0.75". I poured about a table spoon of > ferric chloride on the sponge. I put on my vinyl gloves and started > lightly wiping the board with the sponge. The copper started to come > off instantly and turned the bright-yellow sponge nearly black. I kept > wiping for about 2 - 4 minutes and eventually, all of the copper (that > was not protected by the toner, of course) came off. This sponge > method turned out to be very fast, efficient, clean and easy. Also > saved a lot of ferric chloride. I ended up with a very well etched > board. It was easy to see when it was finished and the etching > solution worked very fast and etched very cleanly. Then I washed the > board and inspected it (and admired it). It would have been perfect > had the toner not smudged. The etching process itself was very clean > and precise. The only trouble was the toner. I need to find a better > way to put etchant-resist onto my copper. > > I then took the almost-finished board downstairs to drill. This part > was not fun as well. I drilled about two holes then gave up because > all I had was a clunky drill and very brittle drill bits. This > drilling part is impossible without a proper drill press. A CNC > machine would be ideal (even a crude one would do the job > sufficiently). So there ya have it. An almost-finished PCB. > > Looks like I'll need to find myself a drill press. > > To all the helped and gave advice, thank you very much. This process > turned out to be fun and educational and I leaned a skill that I'm > sure I'll find very useful in the future. The whole process took less > than an hour and gave very good results. The results would have been > perfect if I had a better method to transfer the toner (via laminator > and a good printer, maybe) and a CNC machine or at least a drill > press. > > What I was most impressed with was the sponge method of etching. Only > a table spoon of ferric chloride was required and none of that > heating/agitation nonsense was needed. The process was clean and > efficient - no spills, little to clean up afterward. So if there's any > of you still pouring the etching solution into a tub and > heating/agitating, I highly recommend that you give the sponge method > a try. It's awesome! > > -- [ solarwind ] -- http://solar-blogg.blogspot.com/ >

Oh, one more item: Get a variety, and several of each size (they will break) drill. I have gotten from Hosfelt and Mouser, but they are readily available, including resharpened. The resharpened may be OK, but caution, some (maybe a lot) of their fatigue life is gone, and breakage is not unusual. Carl Denk wrote: {Quote hidden}> 4 Items: > 1: What was the printer and toner that worked and didn't? > 2: For a drill press, I have used Dremel with very good results. I also > have a 16.5" Delta drill press with 1/16" - 5/8" chuck, and then a > smaller drill size chuck that can be gripped, but wouldn't even think of > using that, although the small drill bits with 1/8" shanks can be > gripped easily. Get the regular PCB drills with 1/8" shanks and short > drill spiral lengths. The long drill bits with same shank diameter as > drill size get slight bends, wobble, and eventually break. > 3: When making the PCB print image, every hole should have a small size > hole etched in the copper. This becomes the equivalent of an accurately > located center punch to get the drill started at the right location. The > drill will wander to that depression if you get close to the location. > 4: For double sided boards, I include a donut at 4 corners, both sides. > Pin prick through the paper before ironing on the first side, drill the > 4 holes through the board, use pins through the papers and holes to > align, and iron on the 2nd side. Have had good results with careful > work, but there are limits to the accuracy. Dips with 0.1" spacing > should be no problem if there are not traces between the pads. With > traces between, probably will scrap some boards, probably would solder > wire across for the a few to be made. :) > > > solarwind wrote: > >> I etched my first PCB today. It came out very well (considering that >> it was the first one I did). I used a mix of different techniques >> which all worked out well for me in the end. >> >> To begin, I made a simple design for a quick prototype board for my >> dsPIC33FJ128GP802. The board itself is very small, just about 1.5" x >> 2.5" (off the top of my head). I had a large sheet of copper clad >> board so I had to cut out the small piece that I would be working >> with. This part was not fun at all. >> >> I printed out my design and traced out the rectangle off a corner of >> the large copper clad board. I then used a utility knife to score the >> sides of my design. It took a while to get deep enough to snap. Then I >> used metal shears to cut one edge of the board. This was an unclean >> cut and damaged part of the large board and slightly warped the copper >> on my design. No big deal. I then stuck the remaining part of the >> board into a vice (with paper towel for padding) and snapped the >> remaining edge. I then sanded the sides with a piece of (metal >> purpose) sand paper. I was then left with a small rectangle of copper >> board ready to be used for toner transfer. I used nail polish remover >> to clean the board. Then I used soap and continued to clean the board. >> Finally, I took some fine sandpaper and scrubbed the board clean. The >> board was now ready for toner transfer. >> >> >From suggestions from my other thread, I tried a different printer. I >> used the same paper (staples glossy paper for laser printers) that I >> had tried before. I set the print quality to the highest setting and >> configured it to deposit the most amount of toner possible. I then cut >> out my design and headed over to my clothes iron. I preheated the >> board by placing a blank sheet of paper of my board and ironing it for >> about a minute. Then I carefully placed my design onto the copper >> board. It stuck instantly. I ironed it for about 2 minutes. (60 of >> those seconds I just left the iron on top and went downstairs to get a >> snack). I didn't do anything special. I just pressed hard (but not too >> hard) and went over it with the tip of the iron. I then filled a small >> sandwich box with water (about body temperature) and dropped my board >> (with the design paper still stuck on it) into the water. I headed >> over to my local grocery store to get some groceries for dinner. By >> the time I came back, the paper was soft enough to peel and rub off >> with my thumb. Some of the toner smudged, but overall, the quality was >> pretty good. The toner had definitely stuck well this time. >> >> Now for the etching part. I took a small dish washing sponge and cut >> out a square about 3" x 3" x 0.75". I poured about a table spoon of >> ferric chloride on the sponge. I put on my vinyl gloves and started >> lightly wiping the board with the sponge. The copper started to come >> off instantly and turned the bright-yellow sponge nearly black. I kept >> wiping for about 2 - 4 minutes and eventually, all of the copper (that >> was not protected by the toner, of course) came off. This sponge >> method turned out to be very fast, efficient, clean and easy. Also >> saved a lot of ferric chloride. I ended up with a very well etched >> board. It was easy to see when it was finished and the etching >> solution worked very fast and etched very cleanly. Then I washed the >> board and inspected it (and admired it). It would have been perfect >> had the toner not smudged. The etching process itself was very clean >> and precise. The only trouble was the toner. I need to find a better >> way to put etchant-resist onto my copper. >> >> I then took the almost-finished board downstairs to drill. This part >> was not fun as well. I drilled about two holes then gave up because >> all I had was a clunky drill and very brittle drill bits. This >> drilling part is impossible without a proper drill press. A CNC >> machine would be ideal (even a crude one would do the job >> sufficiently). So there ya have it. An almost-finished PCB. >> >> Looks like I'll need to find myself a drill press. >> >> To all the helped and gave advice, thank you very much. This process >> turned out to be fun and educational and I leaned a skill that I'm >> sure I'll find very useful in the future. The whole process took less >> than an hour and gave very good results. The results would have been >> perfect if I had a better method to transfer the toner (via laminator >> and a good printer, maybe) and a CNC machine or at least a drill >> press. >> >> What I was most impressed with was the sponge method of etching. Only >> a table spoon of ferric chloride was required and none of that >> heating/agitation nonsense was needed. The process was clean and >> efficient - no spills, little to clean up afterward. So if there's any >> of you still pouring the etching solution into a tub and >> heating/agitating, I highly recommend that you give the sponge method >> a try. It's awesome! >> >> -- [ solarwind ] -- http://solar-blogg.blogspot.com/ >> >>

solarwind wrote: > This process > turned out to be fun and educational and I leaned a skill that I'm > sure I'll find very useful in the future. Everyone that eventually plans to design PC boards regularly should do this a few times. The real lesson is that it's a very costly and pain in the butt way to make mediocre PC boards. For $109 you can get 100 square inches of double sided boards with plated vias, solder mask, and silkscreen. You said it only took a hour, but I doubt that includes even the amortized per-board cost of scaring up the materials, setting up, cleaning up, and the cost of not having plated vias, solder mask, or silkscreen. For a hobbyist, time is worth a lot less than when you're doing this for real. For now it's novel and therefore fun. That will get old fast. Soon enough you'll be making real money, spare time will be scarce, and $109 will look like a great alternative. I experimented with various ways of making PC boards when I was in college and even shortly after. Since I was also into photography and had my own darkroom, I used photographic resist and eventually got reasonably good results. It was fun to do a few times and to figure out the process, but once I had it worked out it just seemed too much hassle to do. Back then (1980) there were no available small quantity commercial alternatives. There was also no PC design software accessible to hobbyists. At work (Hewlett Packard) I was still drawing schematics on D size vellum by hand and a draftsman would take a couple of weeks to lay out a board by hand using calibrated widths of black tape. I even wrote my own auto router, but it wasn't sophisticated enough and the computers of the day weren't powerful enough for it to be useful for anything but small hobby projects. I don't miss those days. ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000.

How big was the drill press? Probably the issue is, with say a unit that will drill 1/2" holes, pushing down on the feed lever can create say 100 lbs. of axial force on the drill bit. Even with a light hand, there will be little tactile feel to a small drill bit. A small drill press with a fine (small increments) of low force feed should give tactile feed. As for shortening and resharpening small bits, forget it unless you have a jig to hold the bit at the correct angles, and do both sides to symmetric shape/location. I used to touch up sharpen bits by hand, but the smallest I could do, and be usable was around 3/16". Now I have a drill doctor drill sharpener. It does great on 1/8" - 3/4". If a bit is not sharpened properly, it won't center on the center punch accurately, walking to the side, and bore ragged oversized holes. In the case of PCB holes, probably would leave ragged copper edges. I have broken more drill bits by hand than with a drill press. The drill press provides concentric force on the bit, minimizing the fatigue from alternating bending stresses. A hand held drill is even with best of technique going to cause the bending fatigue. With a handheld drill motor and a bit 1/8" or less, as you drill, watch the bit for bending. Jinx wrote: {Quote hidden}>>> Tried a drill press once and didn't like it. No tactile feedback. I >>> think I would break more bits with a press >>> >> That's the (huge) difference between 1mm and 0.7mm. The latter >> _will_ break if drilling by hand! >> > > You could be right. Now I think of it I could grind off a lot of > the shank so that maybe only 5-6mm of the bit protrudes from > the collet, which is all you really need for a single PCB anyway > >

> How big was the drill press? Probably the issue is, with say a unit > that will drill 1/2" holes, pushing down on the feed lever can create > say 100lbs. of axial force on the drill bit Yes, I know what you mean. I have a 1/2" bench press that I wouldn't try to use with PCBs. Its chuck just about closes on a 3mm bit. If I need smaller holes, say in 2mm steel that has to be tapped out to 3mm, I've a smaller chuck (from an old cordless IIRC) on a 3/8" bolt to go in the press 1/2" chuck Bits from 1.2mm up can be used in hand drill, especially if the hole is already drilled out with a pilot hole. Not a lot of pressure is needed, actually less than the weight of the drill for the smaller diameters, so you're holding the weight of the drill up whilst the bit is cutting The minidrill press I tried was _OK_ but had no particular advantage over the way I do them free hand. With the drill in my right hand, my left index finger acts to push the drill straight down. With a good bit there's very little resistance. One reason why I never use HSS now. They're alright-ish on phenolic but dull quickly with glass board. I must have done thousands of holes with this HSCo bit and it's still sharp. With care, at an angle, I use it for thinning tracks, removing bridges etc > As for shortening and resharpening small bits, forget it unless you > have a jig to hold the bit at the correct angles I think you misunderstood. If the total length of the bit is 40mm and 20mm protrudes from the collet, then it's the plain shaft end that could be shortened, not the cutting end. I'd have no expectations sharpening a thin cobalt bit successfully > Now I have a drill doctor drill sharpener. It does great on 1/8" - 3/4" I have a Bosch bit sharpener as a drill attachment. For other tools a sanding disc on the wood lathe is pretty good. A belt sander or angle grinder is OK for things like shears, spades and loppers