agent.5 said:
I do. Not only does it prevent oxidation, but it makes soldering so much easier. Not to mention that it's prettier looking too. ;-)
I've been using mostly ETAMAG (which is chemical cold tin plating), which never fails, but: this is pretty nasty chemicals. Just so you know (in case anyone uses it), don't put the used solution in just any random plastic bottle. Put it back in the bottle it comes in. I've tried two different plastic bottles (one bottle of Coke
and another bottle), and it ends up leaking bad (I guess it passes trough the slightly porous plastic material, whereas water or coke stays put). It's also pretty dangerous.I'm contemplating using another way of plating my PCBs, but haven't gotten around to it yet. One way is to use tin paste (the kind that's used for plumbing stuff) and "reflow" it with a hot air gun. Another way I will try is melting some tin alloy in some kind of pan, pre-heat the board and pass the copper side(s) just at the surface of the melting tin.
Hi, I need some help on producing PCB Boards using the UV method. I have a file of a dual mono amp in pdf with the tracks all drawn. What do I need to do?
1) Print the pdf file as a negative, meaning the contents are inverted and produced into a negative. Correct?
2) I suppose to expose the copper board to UV with this negative on top, right? Now, I have access to a 2000W UV lamp with no filter. How long should I expose the PCB?
3) Assuming I have completed step 3, I now have a PCB with an image exposed on it by UV. Is this where I go to get muriatic acid or HCL to dissolve the board and then rinse in running water. If this is correct, how long do you normally immerse the PCB into the solution b4 taking it out and have running water clean it out.
Thanks for any help. I am a noob and can't seem something directly related to this.
1) Print the pdf file as a negative, meaning the contents are inverted and produced into a negative. Correct?
2) I suppose to expose the copper board to UV with this negative on top, right? Now, I have access to a 2000W UV lamp with no filter. How long should I expose the PCB?
3) Assuming I have completed step 3, I now have a PCB with an image exposed on it by UV. Is this where I go to get muriatic acid or HCL to dissolve the board and then rinse in running water. If this is correct, how long do you normally immerse the PCB into the solution b4 taking it out and have running water clean it out.
Thanks for any help. I am a noob and can't seem something directly related to this.
safetyman said:
I fail to find the sensitizing step in your process. In case you are not aware, you need to sensitize the copper board before exposure. This can be accomplished in very different ways with liquid or dry resist, and whether you need a negative or positive mask depends on the selected resist.
Rodolfo
wes-ninja250 said:
Might work nicely. I haven't tried the oven way yet, but I have tried the tin paste + hot air gun way, and I can tell you I'm pretty amazed with the results. I have already made 3 boards this way, and it gives perfect (in my eyes, and compared to cold tin plating) results every time!
Soldering SMDs with a PCB tin plated this way is *so much easier* it's actually incredible. Besides, the plating is thicker than the usual chemical methods, which IMO is an added bonus. And even so, I have yet to have a single shorting due to the hot plating, even with very close traces.
I'll post some pics if anyone wants to see what it looks like.
ingrast said:
Hi Rodolfo,
Thanks for your reply. I have never done this before so I would be very grateful if you or anyone can giude me through this.
Can I use Photoresist PCB like the link below:
Photoresist PCB
or should I use this chemical on a normal board b4 the exposure process:
Electrolube Photo resist
If the above is correct, what do I do after exposing the PCB?
Thank you. Any guidance will be invaluable.
I used the Electrolube spray PR once but it is no longer available here now. It is also rather tricky to attain a good uniform covering.
I highly recommend Think Tinker dry film process. Not only the site is very well documented, a true tutorial on PCB processing among other things, but the dry film is easier to use and chemistry is easy to get and environmentally friendly to boot. It has been my best experience so far.
Look at the site left menu for the PCB processing manual.
Rodolfo
I highly recommend Think Tinker dry film process. Not only the site is very well documented, a true tutorial on PCB processing among other things, but the dry film is easier to use and chemistry is easy to get and environmentally friendly to boot. It has been my best experience so far.
Look at the site left menu for the PCB processing manual.
Rodolfo
Rodolfo, thanks for the pointers. I'll go to the site and do some read up b4 proceeding. I hope that the chemicals are available where I am.
Will come back to report on the outcome later. Won't be able to do anything this week coz I'll be on the road. Hopefully by next week, I'll be back with some happy news.
Will come back to report on the outcome later. Won't be able to do anything this week coz I'll be on the road. Hopefully by next week, I'll be back with some happy news.
LaserStar Film
Anybody tried it?
I think it is a very promising film product for UV light based PCBs production technics
The MEGA Electronic write
Once I had a supplier who make real films out of my PCB layout files but the company sold the equipment and I lost the possibilities.
I have tried LaserStar film not on a Laser printer but on an old LED printer and it worked. (but not perfect due to the old printer) I had to buy me a new laser printer soon not for this purpose but for other main purpose.
You treat the film when printing as any other printable paper/over head film etc. When your PC/Mac program PCB-design is finished (the PCB layout) you simply mirror the image and then print it on a LaserStar sheet. Then you lay the film upside down (printed side against the PCB resist) and air tight on a pre-resisted laminated FR4 material (17,5µ-105µ Cu) and exposure for 3-6 min (depending on UV wattage). Develop and etch it (in Natrium-peroxid-disulfate) and........if everything has gone your way you will end up with a professional PCB
.
Handy "tools" will be a god PC-based PCB layout software (I work on Mac-OS and Im using the Vamp Inc McCAD-professional software) , some sort of UV based lamp equipment (including a timer stop) 
, an etching tray 
, and a good drilling machine. Optional: a tin (Sn)-plating solution or a heating lamp (infra-light) for melting soldering paste 
.
LaserStar film can be bought at "Krepro": http://www.krepro.no/ They also can supply with all the other "things" you will need for a private or commercial PCB production
also at MEGA Electronics they sell LaserStar film : http://www.megauk.com/ you will also find a LOT of other good stuff you will need.
Anybody tried it?
I think it is a very promising film product for UV light based PCBs production technics
The MEGA Electronic write
Once I had a supplier who make real films out of my PCB layout files but the company sold the equipment and I lost the possibilities.
I have tried LaserStar film not on a Laser printer but on an old LED printer and it worked. (but not perfect due to the old printer) I had to buy me a new laser printer soon not for this purpose but for other main purpose.
You treat the film when printing as any other printable paper/over head film etc. When your PC/Mac program PCB-design is finished (the PCB layout) you simply mirror the image and then print it on a LaserStar sheet. Then you lay the film upside down (printed side against the PCB resist) and air tight on a pre-resisted laminated FR4 material (17,5µ-105µ Cu) and exposure for 3-6 min (depending on UV wattage). Develop and etch it (in Natrium-peroxid-disulfate) and........if everything has gone your way you will end up with a professional PCB
.Handy "tools" will be a god PC-based PCB layout software (I work on Mac-OS and Im using the Vamp Inc McCAD-professional software)
, some sort of UV based lamp equipment (including a timer stop) , an etching tray , and a good drilling machine. Optional: a tin (Sn)-plating solution or a heating lamp (infra-light) for melting soldering paste .LaserStar film can be bought at "Krepro": http://www.krepro.no/ They also can supply with all the other "things" you will need for a private or commercial PCB production
also at MEGA Electronics they sell LaserStar film : http://www.megauk.com/ you will also find a LOT of other good stuff you will need.
I use Laserstar all the time, for protoyping.......excellent product for the job,- slightly costly, though.....
However- the texture is extremely similar to the plastic ink drawing film we used back in the seventies and eighties, before CAD.
I cannot find a supplier of this drawing film anymore, but if someone else finds it, it might be worth trying....
this used to be quite inexpensive....
However- the texture is extremely similar to the plastic ink drawing film we used back in the seventies and eighties, before CAD.
I cannot find a supplier of this drawing film anymore, but if someone else finds it, it might be worth trying....
this used to be quite inexpensive....
I've tried everyone that I can find that offers a demo or restricted use download. At the moment I'm mostly using Eagle, but that's fairly clunky as well. I have an old win98 PC that I'm testing a package called Diptrace on at the moment, but to be honest, none of the PCB layout packages seem that well put together, whatever the platform.
rephil said:
One board (it's a CPU board):
An externally hosted image should be here but it was not working when we last tested it.
the picture doesn't really do it justice, it was looking sweet in person. It was made with the toner transfer method, by the way.
Another pic (another CPU):
An externally hosted image should be here but it was not working when we last tested it.
Both were conceived using TinyCAD + FreePCB.
rephil said:
I used tin paste normally used for plumbing purposes. It's about 7 euros for a small bottle (60 g) which allows to make a lot of PCBs.
Haven't had any problem with it. Keep in mind it contains Pb though, so it isn't compliant with RoHS; but I don't think prototype work is really concerned with that.
rephil said:
Ok, a few tips then:
* Water the brush slightly and put it in the tin paste bottle. Don't get too much paste on it at once.
* Spread the paste with the small brush over the whole PCB in a thin layer. It's grayish. There is absolutely NO problem putting it on non-copper areas, so you can spread it on the whole PCB. Just try and make it even. Wear rubber gloves while doing this, as the tin paste can be irritating for the skin and you may touch some while working.
* Use the hot air gun at about 2 cm from the PCB. Set it at max temperature (usually around 500 °C). Don't stay too long on the same spot, as it may burn the epoxy or "unglue" the copper. Make even passes all over the PCB. After a while (usually 2-3 minutes), you can see the tin paste starting to melt and bond to the copper. Use a good lighting, as it is mostly a change of aspect, but it's easy to recognize. When it starts happening, make sure to have the whole copper get this same aspect (it turns silver).
* Let the whole thing cool down for a few minutes.
* Then rinse it thoroughly under tap water while rubbing it with a paper towel. This gets rid of all the unmelted paste, mostly the areas which have no copper on them.
* Done!
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