Hi to everybody,
i would like to know where can i get a good photoresist....but not for an astronomical price...i would say for about 20$ here ?
I have never made any board so i'm totally clueless.
I have just build my machine for the photoprinting with UV bulbs.
I would like to know if the photoresist is a very issue for this process.
I would be inclined to think that spry photoresist is worse.
Hope to receive some hints about this.
Best,
Stefano.
i would like to know where can i get a good photoresist....but not for an astronomical price...i would say for about 20$ here ?
I have never made any board so i'm totally clueless.
I have just build my machine for the photoprinting with UV bulbs.
I would like to know if the photoresist is a very issue for this process.
I would be inclined to think that spry photoresist is worse.
Hope to receive some hints about this.
Best,
Stefano.
Hi Stefano.
Several years ago, i used the Electrolube PRP photo resist spray for PCB manfacture, and i gave very good results, but was very expensive ($35.00 here in Australia)
However, I dont use this anymore.
I now use the precoated boards by KINSTEN, which is excellent, and they are available all over the world.
Do a search on google, and you will find many sites explaining how to do it.
The only tricky part is to work out the exposure.
It can vary from 30min with a flood lamp to as low as 30 seconds with a proper UV lamp.
I use a face tannning lamp that I bought from ebay for $60.00, and it exposes a board in 2min at a distance of 250mm.
One of the best ways to determine the exposure time, is to purchase the cheap phenolic type board, and expose at 1min increments.
If you ever did photograpy, it is the identical procedure to when test strips were done.
The only this to remember that exposure time is also governed by the distance the lamp is away from the board.
Once you ave found the correct exposure / distance record it for future reference.
Hope this helps.
Regards,
George.
Several years ago, i used the Electrolube PRP photo resist spray for PCB manfacture, and i gave very good results, but was very expensive ($35.00 here in Australia)
However, I dont use this anymore.
I now use the precoated boards by KINSTEN, which is excellent, and they are available all over the world.
Do a search on google, and you will find many sites explaining how to do it.
The only tricky part is to work out the exposure.
It can vary from 30min with a flood lamp to as low as 30 seconds with a proper UV lamp.
I use a face tannning lamp that I bought from ebay for $60.00, and it exposes a board in 2min at a distance of 250mm.
One of the best ways to determine the exposure time, is to purchase the cheap phenolic type board, and expose at 1min increments.
If you ever did photograpy, it is the identical procedure to when test strips were done.
The only this to remember that exposure time is also governed by the distance the lamp is away from the board.
Once you ave found the correct exposure / distance record it for future reference.
Hope this helps.
Regards,
George.
Hi Stefano.
Several years ago, i used the Electrolube PRP photo resist spray for PCB manfacture, and i gave very good results, but was very expensive ($35.00 here in Australia)
However, I dont use this anymore.
I now use the precoated boards by KINSTEN, which is excellent, and they are available all over the world.
Do a search on google, and you will find many sites explaining how to do it.
The only tricky part is to work out the exposure.
It can vary from 30min with a flood lamp to as low as 30 seconds with a proper UV lamp.
I use a face tannning lamp that I bought from ebay for $60.00, and it exposes a board in 2min at a distance of 250mm.
One of the best ways to determine the exposure time, is to purchase the cheap phenolic type board, and expose at 1min increments.
If you ever did photograpy, it is the identical procedure to when test strips were done.
The only this to remember that exposure time is also governed by the distance the lamp is away from the board.
Once you ave found the correct exposure / distance record it for future reference.
Hope this helps.
Regards,
George.
Several years ago, i used the Electrolube PRP photo resist spray for PCB manfacture, and i gave very good results, but was very expensive ($35.00 here in Australia)
However, I dont use this anymore.
I now use the precoated boards by KINSTEN, which is excellent, and they are available all over the world.
Do a search on google, and you will find many sites explaining how to do it.
The only tricky part is to work out the exposure.
It can vary from 30min with a flood lamp to as low as 30 seconds with a proper UV lamp.
I use a face tannning lamp that I bought from ebay for $60.00, and it exposes a board in 2min at a distance of 250mm.
One of the best ways to determine the exposure time, is to purchase the cheap phenolic type board, and expose at 1min increments.
If you ever did photograpy, it is the identical procedure to when test strips were done.
The only this to remember that exposure time is also governed by the distance the lamp is away from the board.
Once you ave found the correct exposure / distance record it for future reference.
Hope this helps.
Regards,
George.
i have checked kinsten on the following website:
http://computronics.com.au/kinsten/prices/
the prices seem to be fine.
This business is on Australia so i don't know if they will ship here on Italy.
It's too late for me now...and i'm tired...so i 'll check this tomorrow.
Before to turn off th computer, i want to post and ask some hints on the PCB quality.
I don't know if anybody could explaint to me the different type of PCB available.
§i don't know if there are different board with different quality of copper and thickness of copper.
If there are board with silver instead of copper or gold indeed.
Since i'm making this project for myself and i really want to obtain the maximum and consider all the minimum detail i would ike to pick the best board available.
Hope to learn something new...
http://computronics.com.au/kinsten/prices/
the prices seem to be fine.
This business is on Australia so i don't know if they will ship here on Italy.
It's too late for me now...and i'm tired...so i 'll check this tomorrow.
Before to turn off th computer, i want to post and ask some hints on the PCB quality.
I don't know if anybody could explaint to me the different type of PCB available.
§i don't know if there are different board with different quality of copper and thickness of copper.
If there are board with silver instead of copper or gold indeed.
Since i'm making this project for myself and i really want to obtain the maximum and consider all the minimum detail i would ike to pick the best board available.
Hope to learn something new...
There must be some local source; shipping photoresist could be a problem. It might have to go as hazardous cargo or something.
I think some engravers and lithographers use photoresists. Maybe if you check with dealers in engraving supplies you can find a source for photoresist. Or, just possibly, if you talk to someone who uses photoresist, they might let you have some dregs or leftovers.
If you can get your hands on the photoresist, it _can_ work out much cheaper than buying presensitized boards. But, getting the coating on evenly and not too thick is very tricky. With positive photoresist, I thinned it about 50%, spread it with a disposable foam brush, allowed it to dry, then baked it. I'm not sure how necessary baking was; I think I started doing that because I was impatient.
Thicker board stock is nicer to work with, and thicker copper looks better and obviously conducts better. Glass-epoxy board is stronger than phenolic.
I'm currently using UV fluorescent tubes, F15T8BL (if I remember correctly).
I think some engravers and lithographers use photoresists. Maybe if you check with dealers in engraving supplies you can find a source for photoresist. Or, just possibly, if you talk to someone who uses photoresist, they might let you have some dregs or leftovers.
If you can get your hands on the photoresist, it _can_ work out much cheaper than buying presensitized boards. But, getting the coating on evenly and not too thick is very tricky. With positive photoresist, I thinned it about 50%, spread it with a disposable foam brush, allowed it to dry, then baked it. I'm not sure how necessary baking was; I think I started doing that because I was impatient.
Thicker board stock is nicer to work with, and thicker copper looks better and obviously conducts better. Glass-epoxy board is stronger than phenolic.
I'm currently using UV fluorescent tubes, F15T8BL (if I remember correctly).
Hi Stefanoo !
You should be able to get "Positiv 20" in Italy and I think it should be less then 20 euro. I remember some nice electronics shops in Trieste, when I was there visiting, that might have something like that. Here's a link to some Positiv 20 info, perhaps you can go from there. http://www.crceurope.com/csp/web/Pr...&product=POSITIV 20&business=ELECTRONIC&lng=3
Dangus: Where do you get photo resist in BC?
Frank
You should be able to get "Positiv 20" in Italy and I think it should be less then 20 euro. I remember some nice electronics shops in Trieste, when I was there visiting, that might have something like that. Here's a link to some Positiv 20 info, perhaps you can go from there. http://www.crceurope.com/csp/web/Pr...&product=POSITIV 20&business=ELECTRONIC&lng=3
Dangus: Where do you get photo resist in BC?
Frank
i would prefere to find a photoresist that is not spray; i read that with the brush yu can spread it better.
I still as your help to figure out the differet type of pcb available.
FR4...thiket copper....silver plated....gold plated....
where can i find good quality pcb board to print with photoresist-UV bulb-acid?
I still as your help to figure out the differet type of pcb available.
FR4...thiket copper....silver plated....gold plated....
where can i find good quality pcb board to print with photoresist-UV bulb-acid?
The resists I've used in the past were solvent based, and the thinner you could apply them, the better the resolution. It was common to build a "spinner". This was nothing more than a motor with a plate on the shaft, mounted so the shaft was pointing up. The board was stuck to the plate, and the resist applied to the center and spread around a bit. Then the board was spun, throwing the excess resist off the edges- obviously a guard of some sort is needed- could just be a cardboard ring. This gives a very thin uniform coating for short exposure and high resolution. I don't know if it's necessary or practical for what you'll be using.
Hi Stefanoo,
I buy them in local stores (in as low as single quantity), they are the least expensive quality brand around here.
I've never ordered from them, but e.g. http://www.reichelt.de delivers Bungard material.
Just take care it's not too old. Shelf life of the laquer involved is usally limited to between 6 and 12 months (depending on storage temperature)!
So far only good results, my film quality and exposure timing have always been the limiting factors - as long as the photo resist wasn't over-aged.
Hi Impsick,
The usual developer for positive etch resist laquer is natrium hydroxide (NaOH). Drain cleaner consists of NaOH and Aluminium powder (together with some additives). Some DIYers report good results using drain cleaner with the Al removed. Though NaOH is cheap if you buy at the right places (e.g. not from medical suppliers).
Cheers,
Sebastian.
I buy them in local stores (in as low as single quantity), they are the least expensive quality brand around here.
I've never ordered from them, but e.g. http://www.reichelt.de delivers Bungard material.
Just take care it's not too old. Shelf life of the laquer involved is usally limited to between 6 and 12 months (depending on storage temperature)!
So far only good results, my film quality and exposure timing have always been the limiting factors - as long as the photo resist wasn't over-aged.
Hi Impsick,
The usual developer for positive etch resist laquer is natrium hydroxide (NaOH). Drain cleaner consists of NaOH and Aluminium powder (together with some additives). Some DIYers report good results using drain cleaner with the Al removed. Though NaOH is cheap if you buy at the right places (e.g. not from medical suppliers).
Cheers,
Sebastian.
I get good results giving freshly sprayed boards a 10 minute bake, at the lowest setting that will light the oven's pilot light (about 60C). Then cooling boards for an hour before useing... boards can be given a light coat to cover missed spotlets while its still hot, it will dry quickly.
I agree with the thin coats.. and standing the board on one edge in the oven, helps getting it even... Also rather spray too little and touch up on takeing out of the oven, than too much.
Wish I can get boards developed in 60seconds... always seems to take waaaay longer..unless it all comes off in one shot (too strong solution). I've settled ona bit less than a teaspoon of soda flakes, into 1L of water... the first cup being boiled and the soda mixed into to completely disolve... use something that can stand heat and be carefull... it will boil hard for 5 seconds after you drop the soda in.
I put my boards in for 3 seconds, then run it under the tap to make sure solution is not too strong... else add a tiny bit of water.. or (depending) 2 or 3 flakes of soda diluted in a bit of boiling water, to your solution.
Another common name for caustic soda is lye... and you should get it in any hardware shop... its used for cleaning drains....
I throw a few spoons and plastic kitchenwares in the leftover solution when done developing... you will be amaszed at how much goo comes off things you thought were clean before...
I agree with the thin coats.. and standing the board on one edge in the oven, helps getting it even... Also rather spray too little and touch up on takeing out of the oven, than too much.
Wish I can get boards developed in 60seconds... always seems to take waaaay longer..unless it all comes off in one shot (too strong solution). I've settled ona bit less than a teaspoon of soda flakes, into 1L of water... the first cup being boiled and the soda mixed into to completely disolve... use something that can stand heat and be carefull... it will boil hard for 5 seconds after you drop the soda in.
I put my boards in for 3 seconds, then run it under the tap to make sure solution is not too strong... else add a tiny bit of water.. or (depending) 2 or 3 flakes of soda diluted in a bit of boiling water, to your solution.
Another common name for caustic soda is lye... and you should get it in any hardware shop... its used for cleaning drains....
I throw a few spoons and plastic kitchenwares in the leftover solution when done developing... you will be amaszed at how much goo comes off things you thought were clean before...
Hello Masood,
I have been using CRC Positiv 20 before, although that seems to be a local product. I don't assume that this one is distributed worldwide.
But as a lot of electronics and PCB manufacturing is going on in India, I'm sure you can find something equivalent.
Good luck,
Sebastian.
I have been using CRC Positiv 20 before, although that seems to be a local product. I don't assume that this one is distributed worldwide.
But as a lot of electronics and PCB manufacturing is going on in India, I'm sure you can find something equivalent.
Good luck,
Sebastian.
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