PCB Prototyping Part 2: Solder Mask, Assembly and Testing (Dry Film Soldermask)

Here's how to make circuit boards at home. This second video covers how to apply dry film solder mask (Dynamask 5000), hand solder the SMD components, and test the PCB. The general process is:
1. Print your mask onto a transparency.
2. Expose your board.
3. Develop the mask.
4. Expose the board again.
5. Bake the board for final cure.
6. Solder the components to the PCB.
7. Test for short circuits and proper functionality.
The first video covers how to expose, etch and tin plate a PCB:
• PCB Prototyping Part 1...
Exposure Kit amzn.to/2lHQAfe
Copper Clad Board, Presensitized amzn.to/2ma0M0Z or amzn.to/2lNrlbL
Transparencies for a laser printer amzn.to/2oWVOSR
Sodium Hydroxide amzn.to/2oKAwvL
Hydrogen peroxide (35%) amzn.to/2oKsZx6
Liquid Tin amzn.to/2lHR8BP
Laminator amzn.to/2kOGycW
Sodium Carbonate amzn.to/2lI18Lp
Gram Scale (you need at least 0.1g resolution) amzn.to/2qqUHuY
Tin Snips amzn.to/2oKNoSy
Hydrochloric Acid: go to a home improvement or pool store, it's very expensive online.
Solder Mask: search eBay for "dry film solder mask"
I am a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for me to earn fees by linking to Amazon.com and affiliated sites.

[@liviu201]

When he said that he's going to apply some heatshrink to the design I thought "Oh, so you designed this beautiful board and now you're going to cover it up" but then he used transparent heatshrink. My heart warmed up.

[@sebad28]

Novak jocowic

[@John-vl6hg]

you are cutting the board into the sink. a true engineer.

[@lindamavimbela2744]

Very informative and well paced, thank you. Would've also liked to see the design(software) and breadboarding parts.

[@dd884e5d8a]

Thank you. This two-part tutorial is really useful

[@goodwill7643]

To solder SMD components, you could use solder paste and hit it on hotplate.

[@dushyantchaudharymathura]

Awesome videos, both of them. I have a question regarding the circuit, actually have 2. Why you connected left and right channels to 3.3v using a 4k7 resistor. You said pc microphone has amplifier, what this will do, it will suppress the amplified gain? My 2nd question is op amps require negative and positive power on pin 4 and 8. How you managed with only positive power source. I haven't seen such circuit diagram for op amp. I am sure my knowledge is less here, could you please help.

[@upgrdman]

Most microphones need power, and the pull-up resistor provides that. Your computer's sound card has a similar circuit. And op amps do not require a negative rail unless their inputs or output will go below zero volts, which does not happen with the circuit I used.

[@aha5888]

Great tut. Very informative, thanks 🙂

[@GodzillaGoesGaga]

Minor comment. You typically add a roll-off Cap in parallel to the feedback resistor to stop high frequency oscillations (or downstream sensitivities). Ie to the opamp is a an active lowpass filter with gain!! Great tutorial otherwise. BTW, which solder mask film did you use ?

[@juzekkt]

Dynamask 5000 its in the description

[@behzadabf]

Awesome..that details is realy hepled me.. thank you..

[@paulg.3067]

thanks for the nice video. You are cutting your board (fr4?) with an ordinary tinsnip? Does this work good? I cant imagine that you don't get cracks in the pcb... I used a fretsaw as yet but that cuts not very straight and makes a lot of epoxy dust...

[@upgrdman]

It works well if you use a sharp pair of tin snips. You get a little fraying of the FR4 at the edges, but a quick sanding takes care of that.

[@mkepler5861]

thank you, that was very good tutorial, a thumbs up and a sub from me mike

[@zackchau9272]

In your previous video (Part 1), you showed how to tin plate the board. Can I use a PCB with just the tin plating as the final surface finish, and not use solder mask at all? Will that cause any problem to the circuit board functionality?

[@upgrdman]

Yes, that's fine. The solder mask helps to reduce the chance of solder bridges, and offers some extra protection against abrasion and corrosion. But it's not required.

[@pruthuvinavod7035]

What is the using a solder mask sheet .its photoresistor sheet????

[@chadhidalgo5763]

Would a heat press be as effective as the laminating roller? I saw your previous PCB fab videos and I appreciate the chemistry in these ones much better.

[@upgrdman]

I'm guessing that would be more likely to trap air bubbles under the mask.

[@christianarcfernando7363]

Is it possible to use flat iron instead of laminator?

[@upgrdman]

The rubber laminator rollers help to squish air out. I'm not sure if an iron would work out well.

[@hossamslime9354]

Hi can remove green musk how

[@mplenter9051]

Very helpful video. Thumbs up from me, but you have to learn how to focus your camera when you record in a short distance.

[@mr1enrollment]

have you tried tin plate after solder mask?

[@upgrdman]

I have, and that works fine. But I like the look of tinned copper under the solder mask (the traces/planes look brighter.)

[@mr1enrollment]

ok, just goes thru your fluid faster,... @@upgrdman

[@123yarr]

I like that you solder them on the circuit with the iron not the hot air that is 10 times easier :)

[@upgrdman]

I've used paste + hot air in my earlier PCB videos. If you are hand-dispensing the paste, it doesn't seem any faster than using an iron. A stencil + hot air is by far the best way, but I don't have a way to make decent stencils. I supposed a pneumatic paste dispenser would be a compromise, but I don't have one to try.

[@123yarr]

Ahh, if you had a laser cutter the stencil would be no problem ;) Great tutorial tho! :D

[@johnw1385]

30% hcl + drug store peroxide will etch a flattened pop can...hint hint

[@fraznofire2508]

You can actually get a liquid solder mask that is still uv cured but is easier to apply

[@upgrdman]

I actually tried that before going this route. I could never get a consistent thickness with the liquid mask.

[@habotssar8429]

upgrdman Hi, I definitely agree! solder mask paint is messy! could you please tell where did you purchase the solder mask dry film? thank you

[@ManofCulture]

*HABOT SSAR* at EBAY

[@sivakumarnair1308]

Very useful videos

[@johnw1385]

are you using plexi?

[@upgrdman]

The sheet of plastic I place on top of the PCB is acrylic.

[@johnw1385]

thats likely part of your exposure time issue. Im not sure on the specifics of that film but most of the similar stuff for etch resist responds best to around 370nm wavelength light. AFAIK acrylic starts to absorb under 400nm. Combined that with the fact that your tube isnt a high power uv source to begin with and very little uv is likely getting to the resist. Look for "low iron" glass to pass the most uv

[@ellambydefault9715]

Beautiful

[@BurkenProductions]

an hour wow.. usually take 8 minutes

[@videoaccount5676]

Altium.....you must be rich, or a pirate like me.

[@upgrdman]

Haha, neither. I use Altium at work.