Posts Tagged ‘panelization’

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Fully-assembled boards

2011/06/07

I got a call yesterday that triggered a mad dash to try to get to Canby by 5pm to grab the freshly assembled PCBs.  Not sure they wouldn’t have answered after 5pm, but didn’t want to take the chance, eh? ;-)

The only error was actually caused by Digikey, where somehow they managed to stick a cut tape of some random SOT23-5 part inside a bag marked for SC70-6 parts…  I’ll have to figure that one out with them and mount those parts myself.  Luckily those are on the controller boards, of which there are only 3.

I have to assemble the 3rd board of each stack myself, because I ran them on the DorkbotPDX group order.  That’s because they’re simple by design, so I can run variations more frequently (and cheaper) as I work on fine-tuning that part of the product.  That and the debug board (which I have to solder a cable to) bracket the above boards, making the whole thing quite colorful ;-)

Part of my design is careful re-usability of parts.  The interface boards I’ve designed for upgradability are also snapped onto the controller, so if I come up with a better version I can replace the controller’s interface just as easily as all the others.

The next step of course is to bootstrap them, which is always a very nerve-wracking procedure…  It begs the question though: if the boards are red and purple, what color of smoke should come out if something goes wrong???

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Panelizing PCB & Assembly: prepping the boards

2011/05/26

In my quest to get a group of PCBs fab’d and assembled as inexpensively as possible, the first step of course is getting the artwork for the individual PCBs ready.  Once the schematic is finalized and the basic layout is done, additional steps need to be taken in order to make then panel-friendly, and actually get the artwork together into one chunk.

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The joys of PCB & Assembly panelization

2011/05/24

I’m working on the latest round of prototyping for the product I’m working on.  This time there are a number of factors that are forcing me to change from my previous development methodology.  First and foremost, there’s a lot more pressure to get it done fast rather than cheap, so a major factor is the reduction of unknowns like low assembly yield that were making the process rather slow.  Second, I’ve shuffled things around in the design in ways that both call for tighter design rules than the DorkbotPDX group order provides, and make assembly even trickier to do by hand.

The project itself consists of a whole series of different PCBs.  The main group of 3 boards stack on top of each other, while the controller has a site to stack on the top board from the first stack, then itself live on a larger board that I haven’t finalized yet.  Because of the small quantities of boards and the diversity of the design, panelizing them turns out to save quite a bit of money.  I’m currently running 2 of the main stack plus the first board of the controller.  If I ordered PCBs separately, it’d run about $1500.  Panelized, they came in under $600.  Assembly for each of the jobs separately would run around $3300 based on mostly-accurate numbers, but the panel drops that to around $2200.  Overall I’m saving around $2000 by panelizing.

The downside is that it’s a rather complicated process.  I’ve worked for the last week trying to get everything in order so EpecTec and Screaming Circuits don’t end up with major problems because of what I send them…  However, once it’s figured out the first time, I can do subsequent panelized runs with a lot less effort.  And thanks to the wonders of Open Source, I’m hoping others out there will be able to do the same because of the scripts I’m writing.

I’m going to see if I can make enough time in the next few days to note down most of the issues I’ve run into, and hopefully save others some trouble in doing so.  First up will be setting up the PCBs and panelizing them.