Methods to remove the remaining tabs from PCB Proto Boards? Other than sanding. - Page 1
Forum section: electronics / general

author: t1d
author_rank: Super Contributor
timestamp: July 03, 2023, 08:30:34 am
content: The skin on my hands isextremelyallergic to the fiber glass dust created by sanding off the jagged bits of tabs left after depanelization. So, I am looking for other methods. I have tried snipping them off with cutters, but the tooth just seems to slip off and not really cut off the stubs. Latex gloves are a hassle to put on for 30 seconds of work and they are expensive, since Covid. What works for you?

author: Psi
author_rank: Super Contributor
timestamp: July 03, 2023, 08:37:23 am
content: Get your PCB fab to remove them before you get the PCBs.Most offer a de-panel service, and you can ask for 'machine router' depanel.The PCB panel is put onto a similar machine that created those brake-away-taps/mouse-bites, but this time it cuts right through them.

author: sinewave
author_rank: Unknown
timestamp: July 03, 2023, 10:54:04 am
content: These work great if they are complete tabshttps://www.hakkousa.com/products/chp-tools/chp-hand-tools/depaneling.html

author: SMTech
author_rank: Frequent Contributor
timestamp: July 03, 2023, 11:53:41 am
content: Quote from: sinewave on July 03, 2023, 10:54:04 amThey do indeed, the other thing you can do is put your mousebites inside the outside profile of your PCB so that when the tab breaks off, it doesn't leave a bit sticking out as shown herehttps://www.allpcb.com/mouse_bites_pcb.html.Also I'd suggest its less allergy and more the fact sanding a PCB means you now have thousands of tiny shards of glass jabbing into your skin, which feels super itchy- its like handling loft insulation. Scalper pricing for gloves is long behind us, latex/nitrile gloves are back to being $0.10-20/pair

author: t1d
author_rank: Super Contributor
timestamp: July 04, 2023, 01:57:12 am
content: Quote from: sinewave on July 03, 2023, 10:54:04 amThanks, Sinewave; great suggestion! No, they are not complete tabs, as I am speaking of prototype boards. Those come as depanalized, but with sharp tab bits remaining. Your Hakkos' have me wondering if a cheap pair of sheet metal nibblers might do for the final cleaning. At least it is a great excuse to buy a pair, which is a purchase that I have been delaying.

author: t1d
author_rank: Super Contributor
timestamp: July 04, 2023, 02:13:35 am
content: Quote from: SMTech on July 03, 2023, 11:53:41 amThank you for your input, SMTech. As I am using the prototype services, I do not have control over the mouse bites. But, it would not hurt to try adding a note to my order. I will check glove prices. I would have thought that they would have never come back down.

author: Bud
author_rank: Super Contributor
timestamp: July 04, 2023, 04:33:07 am
content: If this is for prototyping just order individual boards (the fab will route them apart).

author: t1d
author_rank: Super Contributor
timestamp: July 04, 2023, 04:49:51 am
content: Quote from: Bud on July 04, 2023, 04:33:07 amThanks, Bud, but that is not exactly correct... OSH Park boards, for one, come with the tangs attached. They panelize a whole bunch of orders onto one panel, recieve the panel back from the boardhouse, break them apart (leaving the bits) and mail them to the customer.

author: coppercone2
author_rank: Super Contributor
timestamp: July 04, 2023, 04:52:22 am
content: you can get thicker rubber gloves and wash your hands in the sinkyou can also try a nibbler tool to see if it leaves a less jagged edgeand use a sanding stick instead of sand paper. A sanding stick over a trash can with the board in a long hand vise. Or mount a trash can under a vise.

author: Berni
author_rank: Super Contributor
timestamp: July 04, 2023, 05:13:35 am
content: Yeah the dust is really not fun (nor healthy to breathe). Back when i was etching my own PCBs, I hated the drilling part because of the dust.Many ways to go around it tho1) Order the boards individually. At PCBWay you get 5$ per 5pcs 10x10cm 2 layer board or at JLCPCB you can get them for 2$. So even if you order 10 different boards it will cost you only 20$+shipping.2) If you do have to do multiple boards per panel, then panelize them yourself and send them the gerbers of an entire panel. This way you can use a mouse bite design that doesn't leave a protrusion (like arced inwards pattern) and so doesn't need sanding. Or go for V scoring instead, that breaks off in a pretty clean line.3) Get a better cutter for the job. Sometimes you need to experiment. Things like sheet metal sheers work well for cutting PCBs so they might work well for this (the large bench mounted ones)4) Use wet sanding to sand down the tabs. Just wrap the sandpaper around a non water drinking block of something (like plastic), go to the sink, set the water on a slight drip, let it drip on the sandpaper while you are sanding it. The water will help catch the dust and help wash it away so the sandpaper will work more effectively as the gaps don't get packed with dust. Afterwards just rinse both the sandpaper and PCB off with ruining water and you are done.EDIT:My own method is just simply using a file to file it away while holding the PCB inside a trash can to catch the mess. Then use a disposable paper towel to wipe down the dust before lifting it out (the stuff gets absolutely everywhere). Id say gloves won't help much, what matters more is containing the dust and washing your hands afterwards.

author: t1d
author_rank: Super Contributor
timestamp: July 04, 2023, 09:23:36 am
content: Thank you, for your help, coppercone2.Quote from: coppercone2 on July 04, 2023, 04:52:22 amJust ordered these, per post #5.Quote from: coppercone2 on July 04, 2023, 04:52:22 amActually, this makes things worse, because it drives the fibers into the skin. The gloves should help.Quote from: coppercone2 on July 04, 2023, 04:52:22 amJust ordered these, per post #4.Quote from: coppercone2 on July 04, 2023, 04:52:22 amBy coincidence, I am already doing these exact things. Great minds...

author: t1d
author_rank: Super Contributor
timestamp: July 04, 2023, 09:55:58 am
content: Hi, Berni. Thanks for joining in.Quote from: Berni on July 04, 2023, 05:13:35 amHere in the USA, we have a company named OSH Park. They charge a flat $5/square inch/including free shipping/anywhere in the world/for 3 copies/with absolutely no minimum. Yes, all of these details are correct, as written. If you create a 10mmx10mm board (and I have,) they will send it to you for $0.77USD. Because it includes international orders, you should check them out = oshpark.com. So, I can often come out way ahead, on small boards. But, they are the ones that leave the tab bits, the most.Quote from: Berni on July 04, 2023, 05:13:35 amActually, I DIY'd a PCB saw out of a tile saw. So, I can panelize a cheap Asian 100mm board and cut it up, myself. Doing so really stirs up the fiber glass dust.Quote from: Berni on July 04, 2023, 05:13:35 amSee #2, above. Because of the way my saw is designed, it really can't catch just the tiny bits. There is no way to clamp things down, that exactly, on a re-cut.Quote from: Berni on July 04, 2023, 05:13:35 amI had remembered this trick, while posting earlier. Yes, it is an excellent suggestion! It also brings to mind that I used to use a small fan to blow the dust away from my face/body. I had forgotten all about that. I guess a shop vacuum with a HEPA filter might do, as well.Quote from: Berni on July 04, 2023, 05:13:35 amAt this point in your process, a vacuum would be helpful to you.Quote from: Berni on July 04, 2023, 05:13:35 amAgreed!

author: coppercone2
author_rank: Super Contributor
timestamp: July 04, 2023, 09:56:27 am
content: i mean wash reusable rubber gloves in the sinkyou wash your hands, but with gloves on. you don't need epic dexterity of surgeon gloves for filing some crap

author: t1d
author_rank: Super Contributor
timestamp: July 04, 2023, 10:06:02 am
content: Quote from: coppercone2 on July 04, 2023, 09:56:27 amAh yes, that would be helpful to prevent exposure, while removing the gloves. Good point.I forgot to say that, for just knocking off a few tabs in 30 seconds, or so, I usually just put a piece of sand paper flat on the table and press the edge of the board down on it, while pushing the board back and forth. This is when I get the most exposure, because I don't think it warrants a lot of effort to take protective measures for such a small job in the middle of pushing to get things done.I also wanted to say that I am amazed by how much interest and participation there has been in this topic. And, how grateful I am to everyone, for their help.

author: Pinkus
author_rank: Frequent Contributor
timestamp: July 04, 2023, 10:44:18 am
content: These Hakko depaneling tools cannot be found easily here in Europe (e.g. Digikey does not ship these to Europe and there are no sellers offering them).Hint: by looking around I found, that these Hakko pliers are made by Piergiacomi. Thus in Europe just look forPiergiacomi DP24N(or any other width e.g. DP20N, DP25N etc.)- it is the same as the Hakko ones.Though I have not been ably to find cheap Chinese knock offs of depaneling tools yet.

author: coppercone2
author_rank: Super Contributor
timestamp: July 04, 2023, 10:58:56 am
content: Quote from: t1d on July 04, 2023, 10:06:02 amjust fyi get like heat resistant rubber gloves that are stiff they slip on without any stretching their not very stretchy if you go the glove routes its the fastest

author: ajb
author_rank: Super Contributor
timestamp: July 04, 2023, 02:40:32 pm
content: I've taken to putting a file in the bottom of the sink and filing off the tabs under running water. The file is a fairly large and coarse one dedicated to the job, and gets dried off after every use. With a decent quality file and prompt drying it hasn't rusted at all yet. A piece of sandpaper stuck to a chunk of aluminum flat bar as a sanding block would be even better, but I had the file lying around.

author: Nusa
author_rank: Super Contributor
timestamp: July 04, 2023, 04:31:46 pm
content: Metal nibbler does work, if you have one. Another option I didn't see mentioned is a simple wood chisel.

author: thm_w
author_rank: Super Contributor
timestamp: July 04, 2023, 09:55:40 pm
content: Quote from: Berni on July 04, 2023, 05:13:35 amThis is what I do as well.I'm not a fan of using a nibbler or cutter, because it can still result in loose glass fibers. The file smooths the surface to remove them.Just a regular steel file. Haven't tried a diamond file yet, might be worth trying.

author: Infraviolet
author_rank: Super Contributor
timestamp: July 07, 2023, 09:05:45 pm
content: I always found that a D profiled needle file was a good way to go through these tabs, using it in a sawing motion. Unfortunately it does generate the nasty FR4 dust though, although unlike sanding away the whole tab there is less of it generated it and usually falls straight down when doing this (so can all be dropepd in to a bin) rather than being stirred in to the air. I've only done it a few times when I found I needed to order two type of PCB at once, a main large one and a small tiny adapter, and found it much cheaper to merge the adapter as part of the main board and file it off myself rather than order two oard designs together.

author: coppercone2
author_rank: Super Contributor
timestamp: July 08, 2023, 04:14:55 am
content: glue a thing on a vacuum cleaner hose so the D file is offset and attached to the middle of the hose