A Guide For Laying Out 4+ Layer PCBs

June 29, 2012 by Mike Szczys 21 Comments

Learning to lay out a printed circuit board takes some time. But after you’ve churned out a few it’s really pretty easy. If you find yourself at that point it may be time to learn about more complicated board fabrication. We think a good primer is this multi-layer PCB layout guide which [Rik te Winkel] recently put together. It’s one of the results of his internship experience.

One of the major differences with boards that have more than two layers is the ability to alter what layers are actually connected by vias. Vias are plated holes through the substrate that connect different layers of copper. In the case of a 2-layer board these just go right through and connect the top to the bottom. But as you can see above, there are additional choices when it comes to multi-layer boards. #1 is a through via connecting all of the layers. #2 is a blind via; it stops part way through the board. And #3 is a buried via; it connects internal layers but cannot be seen from either side.

The guide is aimed at Eagle CAD. To use more than two layers you’ll have to purchase a license. But we think the concepts can easily be translated to other PCB layout software like Kicad.

An Interview With Laen (the Force Behind Dorkbot PDX)

June 28, 2012 by Mike Szczys 20 Comments

[PT] recently interviewed [Laen], the man who makes it cheap and easy for hobbiests to have small PCBs manufactured. He created Dorkbot PDX’s PCB group order, a rapid turn PCB service which we see used in projects all the time (pretty much any purple PCB has gone through [Laen]).

Turns out his real name is [James Neal]. He’s a sysadmin by trade but deals in recreational circuitry at night. We were surprised to learn that the service has been rebranded. Its new name is OSH Park and it’s got a purple website with a new submission system. In the interview he discusses the genesis of the service. Inspired by a group parts order (that’s a mouthful!) with other hackers in Portland he saw a need for boards on which to mount them. The service has grown so much that he was spending 2-4 hours per night panelizing the designs. He made the wise choice to include an automated submission service in the new website that takes care of most of this work for him.

The rest of the interview spans a large range of topics. [Laen] shares his feelings on getting the boards manufactured domestically. He speaks briefly on the future of the service, and riffs on why open source hardware has value to him.

Repairing A Thermal Imaging Camera

June 22, 2012 by Mike Szczys 15 Comments

[Mike] got his hands on this thermal imaging camera which is designed for use by Firefighters. As he’s demonstrating in the image above, it clips to a helmet and has a display what will let rescuers see through heavy smoke. But this one isn’t working right so he cracked it open and repaired the damaged board.

The hour-long video (embedded after the break) is quite interesting. He starts with a disassembly of the unit, before diving head-first into trouble shooting. There is a PCB inside that fills the entire U-shaped enclosure. The thermal sensor’s habit of cutting out seems to be a symptom of this design. There is one weak point where the board is very narrow. Flexing or vibrating that section will reset the sensor, and [Mike] ends up replacing a couple of components before the thing is fixed. These include a resistor and a ferrite bead both of which are suspected of having cracks due to that board flexing. The rest of the video is spent with an EEVblog-style look that the components and the construction.

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[Ladyada’s] Thoughts On Quick-turn And Small-run PCB Houses

June 13, 2012 by Mike Szczys 50 Comments

So you’ve mastered your PCB layout software, and it’s time to make the board. But if you don’t want to etch your own you’ve got to decided where to have it fabricated. There’s a slew of services out there, most of which you cannot afford, but the short list of those you can is still pretty long. We think this set of PCB fabrication house reviews will help you make your choice.

[Ladyada] — aka [Limor Fried] — knows what she’s talking about. She owns Adafruit Industries and has done the lion’s share of designing the many kits and items they sell. If you’re going to charge money for something it better work right, and that involves lots of prototypes. But even if you don’t need a quick turn-around or numerous testing boards the post is helpful as she also covers some of the batch producers we’re already familiar with. These include DorkBot PDX and BatchPCB to name a couple.

[via Reddit]

Mantis9 PCB Mill

June 13, 2012 by Mike Szczys 30 Comments

This is the Mantis9 PCB mill. It’s the first time we’ve featured the project, but it’s already well known by some as it keeps popping up in the comments for other CNC mill projects. Yes, it’s made out of wood — which some frown upon — but we’re happy with the build instructions and the especially the price tag (parts as low as $85).

We did feature an earlier revision of the hardware back in 2010. Subsequent versions changed the frame to use an open-front design, but it’s the build techniques that saw the biggest evolution. The problem was getting the holes for the parallel rods to align accurately. In the end it’s a simple operation that solves the problem; clamp both boards together and drill the holes at the same time. A drill press is used for all of the fabrication, ensuring that the holes are perpendicular to the surface of the boards. From there the rods are given some bronze bushings and pressed into place. Only then are the platforms secured to the bushings using epoxy. This is to ensure that the bushings don’t bind from poor alignment. We think it should end up having less play in it than other builds that use drawer slides.

Check out a PCB milling run in the clip after the break.

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PCB Manufacturing Tutorial

June 2, 2012 by Brian Benchoff 28 Comments

There comes a time in every maker’s career where solderless breadboards won’t do, perfboard becomes annoying, and deadbug is impossible. The solution is to manufacture a PCB, but there’s a learning curve. After learning a few tricks from [Scott]’s awesome DIY PCB guide, it’s easy to make your own printed circuit boards.

There are a few basic steps to making a PCB. First is designing the board in Eagle or KiCad. The next step, putting the design into copper, has a lot of techniques to choose from. Photo transfer, direct printing, and CNC milling have huge benefits, but by far the most common means hobbyists produce boards is with toner transfer using a laminator.

Unless you’re doing SMD-only circuits, a drill is required. Most people can get away with a Dremel or other rotary tool, but Hackaday has a favorite drill press that is perfect for drilling holes in FR-4. In part two of [Scott]’s tutorial, he goes over solder masks, silk screens before jumping into vias. These small bits of copper conducting electricity through a circuit board are extremely hard for the garage-bound builder to achieve on their own, but there are a few solutions – copper rivets (anyone have a US source for these?) and copper foil can be used, but sometimes the most effective solution is just hitting the board with a lot of solder and heat.

Thanks [Upgrayd] for the title pic.

3D Printed Circuit Boards Using Conductive Ink

May 22, 2012 by Mike Szczys 13 Comments

The thought of using a 3D printer to fabricate PCBs is tantalizing and the good news is that it’s a reality. This project shows that it’s possible to use a special printer head to apply traces to an extruded substrate.

This is similar to the point-to-point 3D printer circuits with one big upgrade. Now the traces can be printed directly onto the ABS using conductive ink. The process starts with the design files, which are used to model a substrate that has a trench for each trace. A Makerbot then prints out this model. Once complete, the ABS extruder head is swapped for a special ink head. Each trace is then filled with the conductive fluid, which is kept in place by the trench walls until it can dry. We think this improves on the trace printing techniques we’ve seen before because it doesn’t require your printer heat to use molten metals.

The circuit above uses printed traces for the high and low side of an LED circuit. It’s a bit rough at the edges, but it shows a lot of promise. Don’t miss the demo video embedded after the jump.

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