for sharpest possible image transfer you do want to flip the F side, since dye or toner is printed on one side of transparency and it should be closest to pcb or some light will refract and spill into transparency and under it
That makes sense although I had to stack two transparencies together or I would get light leaking through. Looking back on the method - I think it produces good results - but its fiddly and takes a *lot* of work to get there. Not to mention after you are done you have to go through and drill all the holes! I had fun doing it though
here's a little tip,mist the board with water ensure the board is fully misted,squeegee all the air bubbles out,the water helps keep a vacuum and causes the film to vacuum suck onto the board,then either iron on or use the laminator. Applying the resist sheet to a dry board just traps air,it's the same thing with dryslide decals the water helps get the air out. Just make sure to squeegee out ALL of the water,you may need to run through the laminator twice or thrice,with the hot iron a sheet or two of kitchen roll to help make full thermal contact and press the film fully onto the board as the board is not perfectly flat. The UV exposure is by far the best method for pcb manufacture,with screen printing a close tie,both use UV exposure for the image,i've tried both ,the silk screen for is more expensive with the negative resist from china being the favoured method for cost effectiveness and less wastefull. You can buy liquid resist thinned with acetone,i have some and i'm bursting to try it out ,it drys in a few hours,i could apply it with a hard rubber roller like lithographic stamps. I have a few sheets of presensitised copper sheet,a 5m roll of the neg resist and the wet resist,for two pcbs no bigger than a square inch or so each,one is a smps booster for tube HT and the other is a buffer op amp for the tubes output,small daughter boards for breadboarding the tubes. I have caustic soda,i had to order the soda crystals for two reasons,one i can't find the caustic soad!!!!!! and second i remember the caustic soda removing the resist layer completely from the board it being a little too aggressive ,big clive (a fellow scot) used the soda crystals and in no time the job was done and in a far less aggressive manner. I'll share another tip i gave to big clive,and another Scottish tip too,the etchant ferric chloride is great in a bubbler tank also in a passive tub,i made tube amps with brass facia plates with the decals etched into the brass,it took ages to cut the brass with it being a copper zinc alloy a lot of smut was building up and frequent use of a babies tooth brush to clear said smut. I found out that a fluid for etching brass and it works amazing on copper,it clears the smut in a passive tank and reduces etch time in an active (bubble) tank,it is called EDINBURGH ETCHANT. Edinburgh etchant is ferric chloride mixed with citric acid,i bought citric acid powder from ebay few table spoons in the tank you have there would be fine,the effect is amazing with regards to how clean and quickly the pcb or brass is etched and the brass particularly noticeably deep and crisp edges,without under cutting as was the case before due to the time taken,the citric acid kept it clear of smut,that's what the pcb bubbles are for,time is reduced considerably to make a pcb,very uniform fast etch,be careful.
Thats a lot for a little tip John! Thank you for the comment though - a lot of good detail here! I had no trouble getting NaOH though - it was down at the local hardware store. The Ferric Chloride mix I had was ferric chloride + HCl - which does go off over time
If you put the transparency in the thin box together with a cotton ball, paper tissue or something similar soaked in acetone for a couple of minutes, you will get much more contrasty print, and won't need to use two transparencies. I had a printing company long ago, and we were printing tons of user manuals for appliances, TV sets and such. We used laser printed tracing paper, and it worked perfectly, no reason why it wouldn't work with transparencies.
Thanks Ian. I use the same process, always nice to see what "tricks" others use. I've never done double sided so your pocket method has given me some confidence. Getting that first film layer off is a pain, I use two bits of tape, one on each side and in the same corner - works a treat. An option for others to get the negative ... in my case print the positive on to paper (I have an ink jet), then take the page to a copier centre ... they can copy on to laminate and those commercial copiers have a setting to print "negative".
Glad you enjoyed Neville. I honestly prefer the "fab in a box" laser toner method. Its far less fiddly. I do think you can get better resolution with the UV method though.
I am not sure if it really worked for me, but I used to completely submerge the board and the resist under water. Then get the resist and board aligned on the top edge. When you lift it out of the water, top edge first, surface tension will pull the resist to the board without any bubbles or wrinkles. As I remember it, there was no "free" water under the film but I assumed the film absorbed some so I let them dry in a warm dark place for a while. BUT I did run into problems which may or may not have had anything to do with the water bath. Often the resist was very resistant to coming off where it should. It is more likely my UV light wasn't diffuse enough, or I was overexposing. I think the film was also getting old and slightly exposed looking off the roll. The other problem, I think might be fixed by doubling up the transparency like you did but for some reason it didn't occur to me to try that. I ended up with lots of little pinholes in the resist and copper. On the other hand, it could have been mini steam bubbles from the water bath and laminater. After etching, I think I removed the resist with acetone rather than lye. Assuming I'm not full of crap, I think that might be a little safer to work with, especially if done outside. Seems like the body even makes a little acetone as part of normal metabolism so it might be equipped to deal with a whiff of fumes every now and then. Anyway, yours turned out a lot better looking then mine but I thought you might want to see if the water bather helps or hurts your process.
Nice video Ian, few tips : 1. Use a small sprayer (like perfume sprayer) filled with distilled water and apply a thin mist of water on (little more cleaned PCB clad- with scotch brite and dishwasher and IPA later) the PCB and then gentle put the UV Resist and use a Squeeze or old credit card to remove any bubble, also removing all the water. let it dry a bit and then put it in hot roller to finally seal it. this will give you mirror finish without any bubble. 2. After developing the exposed PCB un Sodium carbonate, quickly dry the board (in my polluted country, the polluted air attacks the copper in no time) and place a clear OHP sheet on both sides and expose under UV for another 4-5 minutes. this will make the UV mask rock solid. - VU3ECN
Thank you for both the tips. Applying the resist has always been the most painful part for me so I'll definitely give the water mist technique a go! Thank you for the comment.
I have a tool that I bought from the UK at great expense that looks like a gigantic stapler which you can load little tiny hollow copper pins into. When you engage the device it forces the hollow copper pins into the drilled pcb hole and creates a via that attaches the upper and lower copper surface of the board. You can buy the pins with different via sizes. The pins in 1000 quantity aren't cheap either. The tragedy is I've had the device for years but I've never used it.
Thanks Vince - do you have a link to the tool? I think I may have seen it before. Whats the smallest pin diameter you can do with it? Thanks for the comment!
@@na5y Hi, I have pins that are 0.4mm and 0.6mm, there are larger sizes but that's what I was going with. The tool is made by Bungard in Germany. A friend was coming over to visit from the UK so he bought it from the UK distributor and bunged it in his luggage saving me a considerable penny on the whole deal. If you s***r*ch Bungard here you'll find their channel and a demo. Most everything I do now is surface mount, even rf experiments. The PCB turn around times & prices from China don't help either :) Maybe one day when I just have to have a board now then I'll make use of it. The last board I hand made was also surface mount with not that many vias.
It's also worth playing with using a resin style 3D printer which have UV screens so you can expose directly onto the UV resist PCB. I use an Elegoo Mars 4k and it gives very satisfactory results.
I 3D printed a frame which clamps to the two threaded holes that normally hold the resin tray. I have also printed inserts for the board sizes that I most commonly make. These sit within the frame and hold the board firmly in position. The fits are quite tight (interference) so the registration is not too bad, but not perfect (~0.25mm). Mostly I do surface mount stuff with stitching vias to a ground plane on the back and it works quite well. I recently got a desktop CNC, so I might try drilling reference holes and have a milled frame with pins to see if that is better. One day, I might get around to buying another Mars 3 and ripping them both apart to make a sandwich device, but I'm not really doing enough boards at the moment to make that worthwhile!
I bought a 6" 2K LCD with HDMI interface and got the white backlight removed. I got a 42nM UV COB light tp act as light source. I only have a problem. I need to find a program which can project a 1:1 scale referring of a PDF or Gerber file. can anyone give me some pointer.
I did cover it briefly in an earlier video but the company behind fab in a box unfortunately is no more. I believe it was up for sale for a while - but even the old link pcbfx.com is gone. Its too bad - it was a great product and I was very happy with it. There was nothing else out there that did the laser toner method as well. I think you can get better resolution with the UV resist method - but its a *lot* more messing about.
@@na5y I did miss that and also missed their demise. I have some of the pcb in a box stuff (transfer paper and foil) but hadn't had to replenish for a while so didn't see they were gone. Perhaps someone can figure out the magic of the green foil. I think that was the critical piece that they had which no one else has. This technique certainly looks much messier and more complicated.
@@davelapp4740 Yeah the green TRF is awesome. Occasionally I would get wrinkles but overall the method was very reliable. None of the other toner based methods come close IMO - sad to see them go
for sharpest possible image transfer you do want to flip the F side, since dye or toner is printed on one side of transparency and it should be closest to pcb or some light will refract and spill into transparency and under it
That makes sense although I had to stack two transparencies together or I would get light leaking through. Looking back on the method - I think it produces good results - but its fiddly and takes a *lot* of work to get there. Not to mention after you are done you have to go through and drill all the holes! I had fun doing it though
here's a little tip,mist the board with water ensure the board is fully misted,squeegee all the air bubbles out,the water helps keep a vacuum and causes the film to vacuum suck onto the board,then either iron on or use the laminator.
Applying the resist sheet to a dry board just traps air,it's the same thing with dryslide decals the water helps get the air out.
Just make sure to squeegee out ALL of the water,you may need to run through the laminator twice or thrice,with the hot iron a sheet or two of kitchen roll to help make full thermal contact and press the film fully onto the board as the board is not perfectly flat.
The UV exposure is by far the best method for pcb manufacture,with screen printing a close tie,both use UV exposure for the image,i've tried both ,the silk screen for is more expensive with the negative resist from china being the favoured method for cost effectiveness and less wastefull.
You can buy liquid resist thinned with acetone,i have some and i'm bursting to try it out ,it drys in a few hours,i could apply it with a hard rubber roller like lithographic stamps.
I have a few sheets of presensitised copper sheet,a 5m roll of the neg resist and the wet resist,for two pcbs no bigger than a square inch or so each,one is a smps booster for tube HT and the other is a buffer op amp for the tubes output,small daughter boards for breadboarding the tubes.
I have caustic soda,i had to order the soda crystals for two reasons,one i can't find the caustic soad!!!!!! and second i remember the caustic soda removing the resist layer completely from the board it being a little too aggressive ,big clive (a fellow scot) used the soda crystals and in no time the job was done and in a far less aggressive manner.
I'll share another tip i gave to big clive,and another Scottish tip too,the etchant ferric chloride is great in a bubbler tank also in a passive tub,i made tube amps with brass facia plates with the decals etched into the brass,it took ages to cut the brass with it being a copper zinc alloy a lot of smut was building up and frequent use of a babies tooth brush to clear said smut.
I found out that a fluid for etching brass and it works amazing on copper,it clears the smut in a passive tank and reduces etch time in an active (bubble) tank,it is called EDINBURGH ETCHANT.
Edinburgh etchant is ferric chloride mixed with citric acid,i bought citric acid powder from ebay few table spoons in the tank you have there would be fine,the effect is amazing with regards to how clean and quickly the pcb or brass is etched and the brass particularly noticeably deep and crisp edges,without under cutting as was the case before due to the time taken,the citric acid kept it clear of smut,that's what the pcb bubbles are for,time is reduced considerably to make a pcb,very uniform fast etch,be careful.
Thats a lot for a little tip John! Thank you for the comment though - a lot of good detail here! I had no trouble getting NaOH though - it was down at the local hardware store. The Ferric Chloride mix I had was ferric chloride + HCl - which does go off over time
If you put the transparency in the thin box together with a cotton ball, paper tissue or something similar soaked in acetone for a couple of minutes, you will get much more contrasty print, and won't need to use two transparencies. I had a printing company long ago, and we were printing tons of user manuals for appliances, TV sets and such. We used laser printed tracing paper, and it worked perfectly, no reason why it wouldn't work with transparencies.
I'll have to try that - thank you for the tip!
Thanks Ian. I use the same process, always nice to see what "tricks" others use. I've never done double sided so your pocket method has given me some confidence. Getting that first film layer off is a pain, I use two bits of tape, one on each side and in the same corner - works a treat. An option for others to get the negative ... in my case print the positive on to paper (I have an ink jet), then take the page to a copier centre ... they can copy on to laminate and those commercial copiers have a setting to print "negative".
Glad you enjoyed Neville. I honestly prefer the "fab in a box" laser toner method. Its far less fiddly. I do think you can get better resolution with the UV method though.
I am not sure if it really worked for me, but I used to completely submerge the board and the resist under water. Then get the resist and board aligned on the top edge. When you lift it out of the water, top edge first, surface tension will pull the resist to the board without any bubbles or wrinkles. As I remember it, there was no "free" water under the film but I assumed the film absorbed some so I let them dry in a warm dark place for a while.
BUT I did run into problems which may or may not have had anything to do with the water bath. Often the resist was very resistant to coming off where it should. It is more likely my UV light wasn't diffuse enough, or I was overexposing. I think the film was also getting old and slightly exposed looking off the roll.
The other problem, I think might be fixed by doubling up the transparency like you did but for some reason it didn't occur to me to try that. I ended up with lots of little pinholes in the resist and copper. On the other hand, it could have been mini steam bubbles from the water bath and laminater.
After etching, I think I removed the resist with acetone rather than lye. Assuming I'm not full of crap, I think that might be a little safer to work with, especially if done outside. Seems like the body even makes a little acetone as part of normal metabolism so it might be equipped to deal with a whiff of fumes every now and then.
Anyway, yours turned out a lot better looking then mine but I thought you might want to see if the water bather helps or hurts your process.
Nice video Ian, few tips :
1. Use a small sprayer (like perfume sprayer) filled with distilled water and apply a thin mist of water on (little more cleaned PCB clad- with scotch brite and dishwasher and IPA later) the PCB and then gentle put the UV Resist and use a Squeeze or old credit card to remove any bubble, also removing all the water. let it dry a bit and then put it in hot roller to finally seal it. this will give you mirror finish without any bubble.
2. After developing the exposed PCB un Sodium carbonate, quickly dry the board (in my polluted country, the polluted air attacks the copper in no time) and place a clear OHP sheet on both sides and expose under UV for another 4-5 minutes. this will make the UV mask rock solid.
- VU3ECN
Thank you for both the tips. Applying the resist has always been the most painful part for me so I'll definitely give the water mist technique a go! Thank you for the comment.
Just make sure that Transparency Film won't melt at the fusing temperature that fusing rollers operates at.
I don't think transparency sheets made to go into printers are going to melt at the temperatures inside a printer.
I have a tool that I bought from the UK at great expense that looks like a gigantic stapler which you can load little tiny hollow copper pins into. When you engage the device it forces the hollow copper pins into the drilled pcb hole and creates a via that attaches the upper and lower copper surface of the board. You can buy the pins with different via sizes. The pins in 1000 quantity aren't cheap either. The tragedy is I've had the device for years but I've never used it.
Thanks Vince - do you have a link to the tool? I think I may have seen it before. Whats the smallest pin diameter you can do with it? Thanks for the comment!
@@na5y Hi, I have pins that are 0.4mm and 0.6mm, there are larger sizes but that's what I was going with. The tool is made by Bungard in Germany. A friend was coming over to visit from the UK so he bought it from the UK distributor and bunged it in his luggage saving me a considerable penny on the whole deal. If you s***r*ch Bungard here you'll find their channel and a demo. Most everything I do now is surface mount, even rf experiments. The PCB turn around times & prices from China don't help either :) Maybe one day when I just have to have a board now then I'll make use of it. The last board I hand made was also surface mount with not that many vias.
@@na5y If I post a link, seeing as I'm one of the naughty ones, YT will delete my comment and recently they've taken to nuking the entire thread. ☹
@@vincei4252 Say no more ... I did find the video. A beautiful but quite expensive tool!
The Photorest Method is tried and tested.
In Printer Options turn on Enhance Black Printing and you should get really Black Blacks.
It's also worth playing with using a resin style 3D printer which have UV screens so you can expose directly onto the UV resist PCB. I use an Elegoo Mars 4k and it gives very satisfactory results.
I have a resin printer and was thinking that and its an intriguing approach. Thank you for the comment!
I am not sure how you could align double sided though...
I 3D printed a frame which clamps to the two threaded holes that normally hold the resin tray. I have also printed inserts for the board sizes that I most commonly make. These sit within the frame and hold the board firmly in position. The fits are quite tight (interference) so the registration is not too bad, but not perfect (~0.25mm). Mostly I do surface mount stuff with stitching vias to a ground plane on the back and it works quite well. I recently got a desktop CNC, so I might try drilling reference holes and have a milled frame with pins to see if that is better. One day, I might get around to buying another Mars 3 and ripping them both apart to make a sandwich device, but I'm not really doing enough boards at the moment to make that worthwhile!
@@iwbnwif Nice! You should do a video on it! If you do send me a link and I'll include it in the description above
I bought a 6" 2K LCD with HDMI interface and got the white backlight removed. I got a 42nM UV COB light tp act as light source. I only have a problem. I need to find a program which can project a 1:1 scale referring of a PDF or Gerber file. can anyone give me some pointer.
Very interesting video ! Wondering do you need a professional PCB supplier to help you get your project done ?
You should maybe replace the metal tabs in the picture frame come tool every six to twelve months as the tabs are prone to getting brittle and break.
I'm wondering why you switched from your previous method? Perhaps you mentioned why but if so I missed it
I did cover it briefly in an earlier video but the company behind fab in a box unfortunately is no more. I believe it was up for sale for a while - but even the old link pcbfx.com is gone. Its too bad - it was a great product and I was very happy with it. There was nothing else out there that did the laser toner method as well. I think you can get better resolution with the UV resist method - but its a *lot* more messing about.
@@na5y I did miss that and also missed their demise. I have some of the pcb in a box stuff (transfer paper and foil) but hadn't had to replenish for a while so didn't see they were gone. Perhaps someone can figure out the magic of the green foil. I think that was the critical piece that they had which no one else has. This technique certainly looks much messier and more complicated.
@@davelapp4740 Yeah the green TRF is awesome. Occasionally I would get wrinkles but overall the method was very reliable. None of the other toner based methods come close IMO - sad to see them go