You’ve finally decided to take the plunge and build a board with surface-mount parts. After carefully dispensing the solder paste with a syringe, it’s time to place the parts. You take up your trusty tweezers and reach to grab a SOIC-14 logic IC—only there’s not a great way to grab it. The IC is too long to grab one way and has leads obstructing the other. You work around the leads, drop the IC into place, and then pick up an 0402 resistor. You gently set the resistor into your perfectly dispensed solder paste, pull the tweezers away, and the resistor has stuck to your slightly magnetic tweezers. [Robin Reiter] realized that hobbyists and small manufacturers needed a better way to assemble their surface-mount designs, so he’s building the Pixel Pump Pick & Place, an open-source vacuum assembly tool.
Vacuum assembly tools use a blunt-tipped needle and suction to pick up surface-mount parts. Pressing an attached foot pedal disables the vacuum, allowing the part to be gently released. [Robin] thought to include a few thoughtful features to make the Pixel Pump even more useful. It has adjustable suction presets and a self-cleaning feature to blow out any solder paste you accidentally suck up. Most of the non-electronic parts are 3D printed, and [Robin] intends to make the entire design open-source.
[Robin] has a long history of designing tools to make surface-mount assembly easier—you may remember his 3D-printed magazines for dispensing surface-mount parts. If you want to take your PCB assembly setup to the next level, check out the PnPAssist, which shines a laser crosshair right where you should put each part.
Tongue-twister.
The proper first thing to do is demagnetize those tweezers. I used an old handheld tape eraser for that. It worked great until the tweezers touched a magnet. So I did it again and was more careful with magnets! There was still trouble from SMT parts that had trace bits of sticky goo on them, but it made a big difference.
By your own admission, your tweezer method sounds prone to a lot of accidental failure modes.
Maybe you should try vacuum, you don’t have to worry about demagnetisers, and sticky goo…
It’s also cheap and fast. You could probably even use a deguassing coil from a junked tube TV. Show me where I can get a (decent) vacuum pen from so few spare parts. Regular tweezers are also usable for more than just placing SMT parts on a board.
And we can all stand to learn to take better care of our tools.
I’ve also seen folks have a lot of success with ceramic-tipped tweezers. Though, having an inexpensive or diy vacuum tool might win.
Yes, tweezers with ceramic tips are great.
But do get a bunch of them. They are quite cheap, and that shows in their workmanship. The tips don’t always come together nicely.
They are however screwed to the rest of the tweezers, and they are therefore adjustable.
You can also grind them with a “dremel” (like) tool and a diamond disk.
I’ve also modified one of my tweezers. It’s got only one ceramic tip left, and I’ve ground it into a chisel point. The ceramic tip is ground under approx 45 degrees and stays quite sharp for a long time while scraping all kind of stuff. I also use it to cut (enameled) copper wire by pinching it between the chisel point and the FR4 of a PCB.
I would have loved to be able to demagnatize my tweezers! Unfortunately, I worked for several years maybe 20 feet from two MRI scanners, so everything that could be magnetized was magnetized (which was very handy for screwdrivers).
I wonder how are those silicon buttons made for these low quantities. They look very good!
He ordered them from Alibaba.
https://twitter.com/robin7331/status/1367807012684394496?t=qNrxA2WSxpECnLgbcbO7bQ&s=19
https://bohaodz.en.alibaba.com/index.html?wx_navbar_transparent=true&tracelog=sns_minisite
Interesting button manufacturer…
Dongguan Bohao Electronic Technology Co., Ltd. 15 Years Keypad Manufacturer. Free Sample Silicone Rubber Button Pad For Home Appliance. $0.20 – $0.35/Piece, 100 Pieces (Min. Order).
https://bohaodz.en.alibaba.com/product/62037057833-804241342/15_Years_Keypad_Manufacturer_Free_Sample_Silicone_Rubber_Button_Pad.html
https://bohaodz.en.alibaba.com
But the devil may live in the details:
Customized logo (Min. Order: 5000 Pieces)
Graphic customization (Min. Order: 5000 Pieces)
Customized packaging (Min. Order: 5000 Pieces)
Plus I don’t see any NRE pricing for custom molds. But they probably have a bunch of OTS standard molds you can use.
Dongguan Bohao’s market-split: 45% China Domestic, 15% U.S., 10% N. EU, 30% ROTW.
I’m in the U.S. so I searched: “Keypad U.S. Manufacturer”, without the ” “s. I saw a surprising number of good hits. But in my experience the terms “low volume”, “fast turn-around”, and “affordable” are still mutually-exclusive in the U.S. Manufacturing mind-set. But with increased automation and Chinese competition it seems to be (slowly) changing for the better in the U.S.
Jep that is the company that I had those keypads manufactured. Note that I have done the design myself (meaning the 3D cad as well as the print on the buttons itself) and sent those files over to them for manufacturing.
The prices you have in your comment do not include the cost for the silicon molds and silkscreen stencils.
Same. I’m guessing those are either an off-the-shelf part (tough I don’t now where to find it), or custom-made with a 3D-printed mold and transparent silicone such as Smooth-On’s MoldStar 31T. It can also be a soft urethane compound, like the Simpact 60A (I’ve used it before for the same purpose). In any case, it looks like there are only stickers put on top, and color LED’s behind. Anyway, it looks good.
Brian Lough wrote on a hack.io comment:
he talked about it on Twitter before
He ordered them from a store on Alibaba
https://twitter.com/robin7331/status/1367807012684394496?t=qNrxA2WSxpECnLgbcbO7bQ&s=19
They are custom made, ordered at some Alibaba store. You can find a link to a twitter post on the project comments, for some reason I can’t post the link here or my comment gets filtered.
For 80 or 90% of parts, the vacuum is no better. Frankly I’ve never had my tweezers magnetized, just gotten a bit of paste or flux on them, or picked up some static. Wipe em on some paper or a kimwipe and it’s fine. The exact same things happen with vacuum anyway. Then there are problems actually picking up the part with vacuum. Problems with moving the part once it’s on the pads oh-so-slightly wrong. Problems with the hose fucking up your hand position. Problems with the enormous handle and poor button position most of the suffer from.
I’m not against vacuum units, they do have their place – but give me some good sharp tweezers and I’ll put money on placing 01005s faster than you can with a vacuum picker.
I hate these posts that are basically just advertisements. They’ve included no useful design information. They claim it will be open source eventually, but right now it’s not at all.
Maybe you should read his project page and the CrowdSupply page instead of being so negative.
“The source code, STL files and schematics will be publicly available on GitHub once we’re the past pre-launch phase and the campaign has started.”
As someone who owns one of the first few Pixel Pumps, I can say with confidence that the difference between tweezers and this tool is night and day. You can just pick straight out of the tape, instead of throwing a bunch of parts on the table, sorting them right side up and picking them up with tweezers. Also for picking up large parts like TQFP144, there is barely any good alternative to a constant „supply of vacuum“. All vacuum pens I tried before were just not good enough for those.
I also have very dense boards that are basically impossible to assemble with tweezers, as there is virtually no space for the tweeter tips between the 0402‘s and QFNs.
The pen of the Pixel Pump is very light and comfy to use, the hose is extremely supple, you basically forget it exists.
And the best part is the control of Interactive HTML BOMs with the secondary pedal. No more mouse on the soldering bench!