Marker for noting serial number on PCB?

[ctelecaster]

I've got some PCBs made for a run of pedals, and I included your standard white rectangle on the silkscreen layer for a serial number. I've noticed on my prototypes that Sharpie does not stick to whatever ink they use for the silkscreen - it rubs off at the slightest handling. Just curious if anybody had a recommendation for a "more permanent" marker than Sharpie.

 

[Nostradoomus]

Sharpie makes oil based paint based markers that might do the trick, cannot confirm durability though. In the grand scheme of things I’d imagine the board being handled/rubbed after being sold isn’t a huge issue though.

 

[jwin615]

8 solder pads and a binary serial number?

 

[ctelecaster]

8 solder pads and a binary serial number?

Just have to stop at 255 pedals

 

[Brett]

If you have access to them, try Sharpie Industrial permanent markers. They're available in fine point. We used them at my previous business and unless you're trying write something in a smear of grease, I never found a surface they couldn't mark.

 

[ctelecaster]

Looks like Milwaukee has a similar product to the Sharpie Industrial, called Inkzall, that come in an ultra fine 0.5mm tip. I ordered a pack and I’ll let you know if they stick any better.

 

[Silver Blues]

Sharpie Industrials are amazing. I'm not sure if the Inkzall uses an oil-based ink (like the Sharpie Industrial does) but I use them in the lab and they hold up better than normal Sharpies (in this situation we need them to mark when needed but then be erasable with solvent when needed, which they are. Then again, there is no "permanent" marker ink I've come across that doesn't yield to a bit of dichloromethane), but worse than the Sharpie Industrials.

I also wonder if you can hit the white rectangle gently with some very fine (say 1000 grit) sandpaper, and if that would help your ink adhesion.

 

[RetiredUnit1]

In my experience paint pens are far too low on paint and often regurgitate copious amounts of paint at the exact wrong time. There's always the 60's tech

 

[cdwillis]

Did you try wiping the board with alcohol first?

 

[Deperduci]

what was that infamous joke... NASA spent almost a million on a pen could write in space, the soviets used pencils and tape...


Mild sarcasm aside, make the serial part of the packaging along with a note saying keep this for your records.. then like modern businesses you'll look less dick-ish for helpng out who you WANT to help. or put it on the inside of the enclosure.

 

[ctelecaster]

The Milwaukee Inkzall Ultra Fines are good to go - nice 0.5mm tip but the ink sticks much better than an ultra fine Sharpie.

Milwaukee part number is 48-22-3150 if anyone else is interested.

 

[finebyfine]

The Milwaukee Inkzall Ultra Fines are good to go - nice 0.5mm tip but the ink sticks much better than an ultra fine Sharpie.

Milwaukee part number is 48-22-3150 if anyone else is interested.

I was about to say I'll test an extra fine point sharpie oil paint pen on a PCB when I get home but man the price of those Inkzalls looks pretty sweet. Thanks for the recommendation : )

 

[Erik S]

I was about to say I'll test an extra fine point sharpie oil paint pen on a PCB when I get home but man the price of those Inkzalls looks pretty sweet. Thanks for the recommendation : )

I use and like the Milwaukee ultra fines as writing pens, but I'm skeptical they're the right solution for your application - they'll write nicely on metal, but I can wipe off the marks readily with my thumb. I imagine performance would be similar on a board.

 

[ctelecaster]

I use and like the Milwaukee ultra fines as writing pens, but I'm skeptical they're the right solution for your application - they'll write nicely on metal, but I can wipe off the marks readily with my thumb. I imagine performance would be similar on a board.

This was my experience with the regular Sharpie extra fines, but the Milwaukee 48-22-3150’s stayed put when I just tried them.

 

[Erik S]

This was my experience with the regular Sharpie extra fines, but the Milwaukee 48-22-3150’s stayed put when I just tried them.

Oooh, mine says 48-22-3160 maybe I’m not ordering the good ones! Gonna look into that.

 

[Erik S]

Yup. Based on the reviews on the milwaukee site the part number ending in 50 is the one that doesn't wipe off. Gonna have to pick some up.

 

[ctelecaster]

Oooh, mine says 48-22-3160 maybe I’m not ordering the good ones! Gonna look into that.

Yep, the -60s are basically the same thing as the Sharpie Pens - I tried those initially and they wiped right off just like everything else.

The -50s seem to hold on pretty well. Can still be rubbed off, but it takes a bit of effort rather than an accidental swipe of the thumb while assembling.

 

[Nostradoomus]

I think we stumbled upon why builders usually just mark the enclosure.

 

[ctelecaster]

What would we do with our time if we didn’t obsess over the minutiae?