Dry Film Solder Mask

This Instructable is about dry film solder mask, in other words, is the green stuff that is on top of the circuit board.
I like to use smd components in my circuits board because I don't have a computerized drill machine and do in it by hand for a big
boards are really tedious.

Soldering smd components in a copper board without dry solder mask, especially for those little capacitors and resistor of 402 in size, becomes a tough challenge and of course those micro controllers with almost zero space between pins.

So I decided to use the UV curable Ink, sounded very good on those ebay stores with before and after pictures.
I bought a couples of syringes with a success of just one time,  0.1% of my tires worked with a pretty ugly board with an uneven surface an the pads and vias where not square are rounded. 

The Ink sometimes cured, other times it didn't.  Applying the art work is somehow complicated because you have to put it over a wet paint unless you find this miracle tape that is sold in the shipping supplies that is glossy on one side and barely stick to the paint, but not always.

What is for sure is that you are going to get messy and the ink is nothing easy to take out of your hands.

I did a little more research in the web and I found this dry film solder mask,  at least is dry meaning no mess and easy to handle.
I tried and worked wonderfully, no mess, easy, fast and your board looks almost comparable with the professional ones.

to buy the film you can go to my ebay page at this location:

http://www.ebay.com/itm/Dry-Film-Solder-Mask-5-sheets-of-12-x-8-5-in-/150921619738?pt=LH_DefaultDomain_0&hash=item2323a1291a

You can check out these two videos from Youtube:

http://www.youtube.com/watch?v=SDIycwAghL4

http://www.youtube.com/watch?v=VNYIVZgbi9M&feature=related

For making the printed circuit board go to my new instructable here

http://www.instructables.com/id/Dry-Film-Photopolymer-for-making-circuit-boards/

Step 1: Materials

These are the material to make it work;

Laminator:  I use this GBC HeatSeal H220 Quickstart Pouch Laminator is kind of expensive, like $86 bucks, but I am pretty sure you can use the iron to do it, the same procedure that is used for the toner transfer method  Just make sure to put something between the iron and the film, like a rag or a piece of paper and don't over burn it.

One thing that I found is that don't iron your copper clad over a cold surface even though your copper clad gets hot the toner and the dry film does not stick good.
One time I was ironing my art work over my kitchen counter top that is granite and it was kind of cold and the toner never transfered correctly to the copper clad. The first time that I tried the toner transfer method and worked successfully was when I was ironing over a piece of wood. The same applies to the dry film solder mask.

UV light source.  What I use is a 36 Watts UV nail lamp,  $28 bucks on ebay.

Sodium Carbonate:  What is that?  Soda ash or Washing soda.   Go to your near big box store and buy for $7 bucks, in the pool section, the thing that says PH increaser (soda ash),  don't buy sodium bicarbonate is Sodium Carbonate and is powder not liquid.

And finally you need a tray and a brush, (tooth brush is ok).

Comments

[fred27]

I just tried a second board with even better results. I even managed to etch away some text in the solder mask layer.

I included the final step in the manufacturer's instructions - heat for 60 minutes at 150C. I didn't notice any smell so I think it should be OK to do in the oven without poisoning anybody or making your wife angry.

[Beta Mode]

This is one of these instructable that everyone looks for and can't find. It's truly amazing how you can put solder mask on at home! Solder mask is one of those things we take for granted when we solder but when we are on cheap stripboard or veroboard it is hell without solder mask! Well done another instructable which is one of the best! Favourited!

-Harry

[fred27]

Thanks for a great Instructable. I just made my first solder masked board and it turned out great. (The photo taken on my phone in poor light doesn't do it justice.)

It was a CNC milled through hole board so a had little more "contour" on the surface than yours. I found that passing the mask through the laminator once cold and then once again on the lowest heat setting worked best. Too much heat and pressure caused the mask to be a bit thin over some tracks.

I also only used 2 bulbs in the UV nail lamp. I took out the side two to decrease the chance of light creeping under the transparency. It still seemed bright enough and worked well.

[cpeniche]

Looks great. I am going to try to run it first on cold and then with less heat. I noticed as well that with too much heat you get a thinner mask. I will publish the exact process parameters that are recommended in the specifications for those guys that can control the heat and pressure of their laminators or the intensity of their uv lamp.
I remember also that after curing the mask for at least 30 minutes with the UV light they recommend to heat it in an oven but I don't have here right now with me the exact temperature and time. But what I remember is that the oven shouldn't be used again to cook food because the solder mask expells fumes.

Great job and I am glad that you liked the product!!!

I also offer the dry film photopolymer in case you need to go with thinner vias and more complicated circuits that are difficult to route with cnc machines. I have a instructable for this product as well here, just search for dry film photopolymer.

[raypsi]

This may seem lame, can you etch a board using this stuff will it survive ferric chloride solution? and what is the resolution how small of a via could you make?
I got a teflon sheet for T shirt transfers to use with an Iron.

[cpeniche]

You can etch the board with this film and of course will survive the ferric chloride. BUT your are going to have a very hard time trying to remove it. This stuff is made to last and stay there forever. To remove it you have to use a stripper solution. I don't know how the solution is made but I think this is not something easy to find in the stores.

[raypsi]

Thanks I'll be getting sum next week, I got an electric palm sander with aluminum oxide sand paper and then wet sandpaper to make it smooth once I get down to the copper, Then use a halogen chop light with the uv filter removed to expose it.
I remember how to make sodium bicarbonate into sodium carbonate, on a cookie sheet in the oven at 400 degrees F for 30 minutes.

[cpeniche]

Hi

Know I am showing here in the instructable how to use the dry film phtotopolymer that is designed for etching circuit boards. I think with this photopolymer you can go up to 40 micrometer of resolution and is very easy to use.

Search for dry film photopolymer for making circuit boards.

Hope you like it

[lookwhatjoeysmaking]

now all you need is to add silk screen

[broman2]

I work at a shop that makes circutboards, and silk screening is the way to go. If you want to mass produce the boards, otherwise this is a great and inventive consumers way of doing this.

[tronicgr]

Maybe you can print on this film the silkscreen layer and stick it on the top... but what can you use for white ink?

[cpeniche]

For the silk screen let me do an experiment. I will print the components layout on the board using the toner transfer method and on top I will apply the film. The film is green but may be transparent enough to see through .

What I am sure is that the toner doesn't stick to the film, I already tried and it didn't work.

[offtherails2010]

AWESOME & FINALLY us home-brewers can have professional looking PCB's too !!!

VERY NICE FIND !!!

One Quick Question though...

Was the artwork matching vias and pads printed on what looks like transparency media ? Or Tracing Paper ? Or Something else ?!!!!?

[cpeniche]

Is a transparency. You need the UV light harden the paper except for the vias and pads that later are going to be remove with the help of the sodium carbonate.

[offtherails2010]

thats great - thanks !!!!

very nice & clear photo's, im already hooked !!!

but would you do bulk discounts on this Dynamask ???

[cpeniche]

If you can go to ebay and send me a message on what exactly you need we can work out something.

or to [e-mail].

[dustinandrews]

Very nice. Now all we need a is a good way to plate through holes. In my toner transfer instructable MCUman says "Harbor Freight sells a 9" laminator for 30 bucks. I've had mine for a couple of years now, I use it often, and it works GREAT! Item number 92499."
I'm going to link this one on the end of mine.

I often use kaptop tap and a hobby blade to make masks for the tricky parts. I am going to try it with a laser sometime.

[cpeniche]

Thanks!!! I am going to try the toner transfer method with the parchment paper. I usually use presensitize boards with the UV light source I am using for the solder mask. Works great for 28 bucks.

45 seconds under the UV light is perfect to get very good traces on the presensitize board with UV light. For fluorescent light is about 8 min to 15 min.

But to be honest your are not going to find always a good presensitize board. I bought one that never worked, not matter the timing, it never worked unlike the second board I bought it worked wonderfully. That's why I don't discard the toner transfer method.

If I get successful with the photosensitive dry film to make traces I'll post a instructable.

[lookwhatjoeysmaking]

vary nice this is soo cool.

[cpeniche]

Thanks.
And very easy to do it

[Darryl75]

Very good instruction !

[scpz]

artistic approach.