PCB Etching

[nelson]

Hi, here is a link that show us another way to make good pcb´s at a very low cost.
http://www.pbase.com/sinoline/pcb_experiments

Also i m showing my TR locator pcb made by this way

Regards

Nelson

[Geo]

Hi nelson.
I tried it with photocopier machine but without very good results . I used oil-paper, simple photocopy paper, HP-glossy paper, slide paper, epson photo quality paper....but nothing special. Maybe the problem to was the chemical liquids because they was very light (about 1 hour to finish the pcb ).

[nelson]

PCB etching

Hi Geo.
I used laser printer, with couche paper number 90 to 120 is ok. Dont use photo paper, is expensive and have for me no good results. This paper is normaly used on good presentation magazines cover. Then i iron the picture on the pcb.
After that i apply quemicals. Time is around 5 to 15 minutes with very good results.
Regards
Nelson

Hi nelson.
I tried it with photocopier machine but without very good results . I used oil-paper, simple photocopy paper, HP-glossy paper, slide paper, epson photo quality paper....but nothing special. Maybe the problem to was the chemical liquids because they was very light (about 1 hour to finish the pcb ).

[Max]

Hi nelson.
I tried it with photocopier machine but without very good results . I used oil-paper, simple photocopy paper, HP-glossy paper, slide paper, epson photo quality paper....but nothing special. Maybe the problem to was the chemical liquids because they was very light (about 1 hour to finish the pcb ).

Hi Geo,
I've tested hydrocloric acid many times and with very good results...not time only (less than 4 minutes)...but real problem is that you need a very good protective film on PCB before apply chemicals...and that these mixtures produce lot of fumes...vapours...really reactive and irritating skin, eyes...etc.
Must handle with lot of care...mixture of hydrocloric acid and H3O...not so good to breath. But outdoor it works pretty well.
Real problem is not a good and transparent etching fluid...but how to make good and repeatable "covers" on copper...
I've used iron on PCB with press-and-peel sheets that are expensive and monouse...but give very good results. Problem is that for me 1 A4 sheet of p&p costs about 5 eur...not cheapy !
They are made of teflon-like plastic...you just need to print with a laser-printer your mirrored pcb drawing then hot-iron on copper for 2 or 3 minutes and voilla ! Near to perfect transfer of toner !

If you can find them at a low price...you'll solve any problem with PCB making.

Best regards,
Max

[nelson]

PCB etching

Sorry but i insist, use couche paper that is low cost.
Max, try to use less acid. Time will be more, about 5 to 15 minutes, but results are excellent. On my pcb´s i also got the very small text printed on it.
Regards
Nelson

Hi Geo,
I've tested hydrocloric acid many times and with very good results...not time only (less than 4 minutes)...but real problem is that you need a very good protective film on PCB before apply chemicals...and that these mixtures produce lot of fumes...vapours...really reactive and irritating skin, eyes...etc.
Must handle with lot of care...mixture of hydrocloric acid and H3O...not so good to breath. But outdoor it works pretty well.
Real problem is not a good and transparent etching fluid...but how to make good and repeatable "covers" on copper...
I've used iron on PCB with press-and-peel sheets that are expensive and monouse...but give very good results. Problem is that for me 1 A4 sheet of p&p costs about 5 eur...not cheapy !
They are made of teflon-like plastic...you just need to print with a laser-printer your mirrored pcb drawing then hot-iron on copper for 2 or 3 minutes and voilla ! Near to perfect transfer of toner !

If you can find them at a low price...you'll solve any problem with PCB making.

Best regards,
Max

[Geo]

I tried a lot of time without very good results. So i returned back to the classic methods
1. With photosensitive pcb's. Perfect work but a little expensive and there is problem if you have the pcb long time (especially near the ligh).
2. with the hand and a water resistance pencil. Good results but only for very simple boards .
Regards

[chemelec]

I tried a lot of time without very good results. So i returned back to the classic methods
1. With photosensitive pcb's. Perfect work but a little expensive and there is problem if you have the pcb long time (especially near the ligh).
2. with the hand and a water resistance pencil. Good results but only for very simple boards .
Regards

Get some "Shipleys Photo Resist" and Coat your own Boards. MUCH Cheaper.

I Keep my Sensitized boards in a Dark File Cabnet, Copper Side Down and they last more than a Year.

[Max]

I tried a lot of time without very good results. So i returned back to the classic methods
1. With photosensitive pcb's. Perfect work but a little expensive and there is problem if you have the pcb long time (especially near the ligh).
2. with the hand and a water resistance pencil. Good results but only for very simple boards .
Regards

Hi Geo,
yes it's true. I've also tried a lot of times with other papers...results no good or not repeatable.
I agree with 1. and 2.

For 1. as Gary stated you can coat your boards too. I'm using at now presensitized boards...that as you know are little expensive , expecially when large pcb is needed. I'm an "expert" in making photosensitive boards...I maked them for at least 6 years with lot of success.
You need aerosol spray (try to find FR chemicals if you can...but there are many). Just polish very carefully your board before sprying, need very uniform and thin layer of photoresist...then you must keep it dry using an oven resistance in a box....something like an oven...for about 20-30 minutes.
Then you can cover with dark paper and store well for 1-3 years without any problem...like with pretreated pcb (the ones with protective plastic film).

When you need just take one out...cut it and use as a pretreated one.
Results are very good if you do well spry and drying. Much like with bought pretreated boards.

I maked also double side boards this way...for years...with no problem at all.

Only thing worse is smell...when you spry that stuff or when boards drying...I've adbandoned because of this reason...but if you have a good workshop away from the house this is not a problem.

Another issue is spray cost and where to find "newer" cans...remember that photoresist compound is not really stable when in solvent/can and after 1 year or so it degrades a lot giving bad results: so best thing is to have a god can and a set of boards...then making them all and store them dryied.

Also you can do every time you need...but for me doesn't work well because of the bad smell the process gives. I remember I can smell it a week later exposition also on clotes !

Best regards,
Max.

[Max]

Sorry but i insist, use couche paper that is low cost.
Max, try to use less acid. Time will be more, about 5 to 15 minutes, but results are excellent. On my pcb´s i also got the very small text printed on it.
Regards
Nelson

Hi Nelson,
I'm sure you are right...and method works fine for you, but maybe it depends on your paper type. I've tryied many times with common paper and also photographic paper (FUJI) without good results...even broken tracks...no little details.
Maybe also toner quantity is too important this way. I get good results using only press-and-peel this way.
Then adbandoned and used the old but ever good (still now) photo-sensitive process. It costs me less that a press-and-peel ! I have lamps etc...so for me is not a big problem to make this way...only the cost of treated PCBs.

Best regards,
Max

[Geo]

Gary thanks , i will give a look at this product. I have a lot of boards that are photosensitive destroyed (from long time....2...5 years ago ), so i am looking for a simple and easy way to construct them (an other way is to make them electronic boxes by soldering the boards ..he..he.). I know you will say "why you buy a lot of boards if you don't need them "... yes you have right but when i find boards at the only electronic shop that there is at my City i buy some "only to have boards". What can i do "Hobby is hobby".
When i was young i did not have lot of money to buy and construct everything that i wanted. Now i have money but i have not time for this hobby (electronics) so the only that i do is to buy components...instruments..etc.
Max... Thanks for your reply. But I'm an "professional" in making photosensitive boards...I maked them for at least 25 years (if i remember right) with full of success . As i wrote to Gary i try every simple way to construct boards (i construct every year only 5...10 boards ... so what i say here ha...ha). When i try any way to make boards the result is that "i spend very happy my time ".
That is all
My regards

ps I forgot... i think that with the iron method (that Nelson told us) it is not possible to make two side boards with good precision

[chemelec]

Gary thanks , i will give a look at this product. I have a lot of boards that are photosensitive destroyed (from long time....2...5 years ago ), so i am looking for a simple and easy way to construct them (an other way is to make them electronic boxes by soldering the boards ..he..he.). I know you will say "why you buy a lot of boards if you don't need them "... yes you have right but when i find boards at the only electronic shop that there is at my City i buy some "only to have boards". What can i do "Hobby is hobby".
When i was young i did not have lot of money to buy and construct everything that i wanted. Now i have money but i have not time for this hobby (electronics) so the only that i do is to buy components...instruments..etc.
Max... Thanks for your reply. But I'm an "professional" in making photosensitive boards...I maked them for at least 25 years (if i remember right) with full of success . As i wrote to Gary i try every simple way to construct boards (i construct every year only 5...10 boards ... so what i say here ha...ha). When i try any way to make boards the result is that "i spend very happy my time ".
That is all
My regards

ps I forgot... i think that with the iron method (that Nelson told us) it is not possible to make two side boards with good precision

The Shipleys Photo Resist I use is the Liquid, Not the Spray. Its a bit harder to work with, but considerably cheaper. It can also be Deluted down, up to 4 times with a solvent. I coat 12 Inch by 16 Inch panals and store them that way.

Although it's supposed to have a fairly short "Shelf life", I find that if I also keep it in this Dark, File Cabnet Drawer, which is also in a cool temperature area of my house, it keeps well for More than 10 years.

I buy a "Quart" of it at a time. The last time I bought it, this Quart of resist cost me $50.00 in Canadian money.

A Quart will Coat Several Thousand Square Feet of Raw Circuit Board. Probably more than you will ever need in your life.

[Geo]

Hi Gary.
I will try to order it and to try it with some boards.
Anyway thank you. It is a different way to do photosensitive boards
Best wishes

[Delbert grady]

dangerous stuff

So why mess about whith this dangerous stuff when Ferric Chroide works OK and is low cost. I use mono laser printer onto film. Then home made UV light box, with sunbed tubes. Then Ferric Chloride. Works a treat, even for fine tracks.

[Max]

So why mess about whith this dangerous stuff when Ferric Chroide works OK and is low cost. I use mono laser printer onto film. Then home made UV light box, with sunbed tubes. Then Ferric Chloride. Works a treat, even for fine tracks.

Hi Delbert,
do you mean acid and H3O? Yes. Is a bit dangerous to handle or breath this stuff. But is really fast. Much faster than Ferric Chloride and also transparent. There are also many similar mixtures on the market too...that are a bit more safe.
Big advantages are on cold sites...where cold chloride requires more than 1 hour to do the job.

Best regards,
Max

[Delbert grady]

Warm it up

Sorry I forgot to say I always get the ferric quite warm/hot can do a board
in about ten mins. If its cold can take an hour. I put the ferric in a 10/8 photographic tray that is just about floating in a bigger tray with boiling water in, then float the board face down on top of the ferric. Check it from time to time to make sure there are no trapped air bubbles