SMT and Thru-Hole Desoldering

My introduction to electronic manufacturing was as a production technician at Pennsylvania Scale Company in Leola PA in the early 1980’s. I learned that to work on what I wanted to work on I had to get my assigned duties done by noon or thereabouts. The most important lesson I had learned as a TV repairman, other than not to chew on the high voltage cable, was to use your eyes first. I would take a box of bad PCB’s that were essentially 6502 based computers that could count and weigh, and first go through inspecting them; usually the contents were reduced 50% right off by doing this. Then it was a race to identify and fix the remaining units and to keep my pace up I had to do my own desoldering.

Desoldering with IR System

Desoldering with IR System

It worked like this; you could set units aside with instructions and the production people would at some point go through changing components etc. for you or you could desolder yourself. I was pretty good at hand de-soldering 28 and 40 pin chips using a venerable Soldapulit manual solder sucker (as they were known). But to really cook I would wait for a moment when the production de-soldering machine was available. There was one simple rule for using the desoldering station: clean it when done! Failure to do so would result in your access to the station being suspended and then you might also incur the “wrath of production” which was not limited to your lunch bag being found frozen solid or your chair soaked in defluxing chemicals.

[Read more...]

3D Printed Trays for your Pick and Place Machine

3dprintedPNPTray Pick and Place machines are one of the double-edged swords of electronics.They build your boards fast, but if you don’t have everything setup perfectly, they’ll quickly make a mess. A pick and place can’t grab a resistor from a pile and place it – so far only humans can pull that one off. They need parts organized and oriented in reels or trays.

[Parker Dillmann] had to load some parts, but didn’t have a tray for them, so he 3D printed his own. [Parker] works at a small assembly house in Texas. He’s working on a top secret design which includes FFC connectors. Unfortunately, the connectors shipped in pick and place unfriendly tubes rather than reels. If he couldn’t find a tray, [Parker] would have to hand place those connectors as a second operation, which would increase the time to build each board and leave more chances for mistakes.

Rather than place each part by hand, [Parker] got in touch with his friend [Chris Kraft] who is something of a 3D printing guru. [Chris] confirmed that a 3D printed tray would be possible, though the PLA he prints with was not static safe. That was fine for the connectors, but [Parker] was hoping to save some tray space by putting his PSOC4 chips in the printed tray as well.

[Parker] used SketchUp to design a tray that would fit his Madell DP2006-2 pick and place. He left .15mm clearance around the parts – just enough to cover any inaccuracies during printing, but not enough to throw off parts placement. He sent the STL file over to [Chris] who used Simplify3D to a create a Gcode file. [Chris] printed the tray at .2 mm layer height on his MakerGear M2 printer, and the results looked great. Would they be good enough for the pick and place machine?

[Parker] received the printed trays in the mail and loaded them with parts. The pick and place had no problem finding and placing the connectors, making this job a huge success. [Parker] even left room for the PSOC4 chips.He plans to paint the tray with anti-static paint before giving them at try.

We really like this story – it’s a perfect example of how 3D printers can speed up processes in manufacturing. Now that the basic design is done, creating new trays is a snap. Nice work [Parker] and [Chris]! [Read more...]

Hackaday Links: May 25, 2014

hackaday-links-chain

[Matt] wanted his own light saber. You could argue that this is nearly as dangerous since you can’t see the beam and it doesn’t end a few feet past the business end of the grip. Plus there’s that who “not actually a Jedi” thing.

We don’t know if retro computing fans are going to love or hate this (translated). On the one hand it’s pretty cool to see a ZX81 clone up and running. On the other hand, an Amiga 600 case was sacrificed to serve as the body for the hack. [Thanks Juan]

Watchdog timer. If you know what that is your mind immediately says “good idea” when you hear the word. If you don’t know, you need to learn. Watchdogs are reset timers that are built into most microcontrollers. If your firmware gets stuck and doesn’t maintain the timer’s counter at a regular interval the watchdog it will perform a hardware reset and hopefully your hardware will start functioning again. Here’s a guide for using the watchdog in an Arduino, but the concepts are pretty much universal.

We see all kinds of stepper-motor based music machines. One of our favorites was this recent floppy drive jukebox. But not every song is going to sound good on this type of hardware. One that does sound especially neat is the Doctor Who theme on an array of 8 drives.

And finally, if you’re struggling with surface mount soldering we recommend grabbing two soldering irons. But in a pinch just grab some heavy gauge copper wire and wrap it around your soldering iron tip. It ends up being a two-point soldering iron set for the size of specific components such as 0805 resistors. [Thanks Rupert]

Manual Pick and Place

picknplacePopulating a large surface mount PCB can take forever. [craftycoder] from Freeside Atlanta has built a great looking manual pick and place machine, removing the need for tweezers. No more will passives stick to your tweezers while you are trying to place them on your PCB!

We have seen a lot of pick and place machines in the past few years. What makes this one stand out is its simplicity and the no-nonsense build. This pick and place is built on an MDF platform, uses bearings from Amazon, standard 12 mm rails, and has a small camera for a close-up look at your part placement. Sure it is a manual method, but it beats painstakingly placing each part with tweezers. It would be interesting to see how much this entire build cost; we expect that it was not too expensive. See this thing in action in the video after the break.

We hope this project has inspired you to go out and make something cool! If so, let us know what you have made!
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This SMD Reflow Hot Air Gun Hangs Around Your Workbench

smd_reflow_hot_air_gun_nc_80

Has reflowing surface mount components got you down? [Giorgos] is currently working on a project that will lift your spirits…. well at least your hot air gun. Tired of manually holding his heat gun in one hand and IR thermometer in the other, [Giorgos] set out to create a device to alleviate just that. Although not completed yet, it appears the machine’s intent is to hold the heat gun at an appropriate height above the work piece in order to achieve the correct reflow temperature. He doesn’t say how the height of the hot air gun will be controlled. We’d like to see a microcontroller adjust the height of the hot air gun depending on the temperature of the component to be reflowed. [Giorgos] gives an extremely detailed account of his build process. Make sure to check out all four pages of the project post!

We’ve seen a lot of interesting work from [Giorgos] over the years like this capacitive touch-pad entry system.

[via Dangerous Prototypes]

Semi-professional board assembly for your workshop

[Zach Hoeken] has the answer to assembling multiple surface mount PCBs in the home workshop. It’s certainly not for everyone. But if you’ve ever thought of marketing your own small runs he has the equipment and methodology you need.

He had tried using hacked together equipment, but after encountering a range of issues he finds the investment in a few key items saves time and money in the long run. The first is a precision tooling fixture block; that metal plate with a grid of holes that makes up the background of the image above. It comes with machined pegs which fit the holes perfectly, and as you can see, his panel of 16 boards include tooling holes that line up with the fixture. Once in place, a steel solder stencil is aligned with the board using its own tooling holes. The alignment of the stencil and its uniformed thickness ensure that the perfect amount of solder paste is easy to apply with a squeegee. [Zach] hand places his components but he did invest in a proper reflow oven to make the soldering a set and forget process.

Manga Guide to SMD

For those that have always felt a bit treppidatious when approaching SMD, you can relax. Here’s a simple guide to walk you through your first shaky steps into surface mount devices. Distributed freely under the creative common license, the Manga Guide to SMD is an 18 page comic that has a goal of making SMD producers out of all of us. There’s a good visual explanation of what SMT is and why we use it, as well as a thorough walk through of how to solder the tiny devices with your soldering iron. They don’t go into dealing with a small reflow oven in this issue.

If this fits well with your learning style, you might also be interested in the Manga Guide to Electricity.

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