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by zenwebb on Fri Jan 17, 2014 8:24 pm

I've been working on a board for a while now that uses all SMT parts (except for a few PTH headers), and have been trying to crack the nut of manufacturing them for quite a while.It only has three common ICs and about a dozen passive components, but I'm having some real trouble finding a PCBA service that will allow me to offer the boards at a price point that people will actually buy!

I want to keep my retail price to around $25-$30, as I don't think anyone will want to pay more for how simple the board is. The parts total per board is $7.17, so I was hoping that even with PCB manufacturing and SMT assembly the total unit cost would be $15 or less. This would allow me to have a markup of 2-3 times the unit cost, which I know is important from Limor's writings and other available info.

Every single supplier I have requested a PCBA quote from (except one) gives me a number between $3,000 and $4,000 for a run of 100. Adding in the cost of parts and shipping, the base unit cost per board would end up being over $40!

The one supplier I have found (and heard good things about) would be Seeed Studio's Propagate service, which would allow me to keep unit costs down to a more reasonable $15 per board. However, their English is not so good, and I'm a little cautious of what will happen if manufacturing quality ends up being bad or miscommunicated.

Does anyone have any advice for an individual maker (hobbyist wanting to turn professional) for making a profit on simple boards and production runs of about 100?
Jason Webb - grad student, creative technologist, OSHW engineer
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by waltr on Sat Jan 18, 2014 10:45 am

That is a tough one for only 100 units.
Are you looking to have both the PCB made and installing all the SMT parts?
Are they to also buy the parts?
Were the quotes you get broken down to show the NRE (setup up) cost and then the cost per unit?
This NRE cost is what can really kill the price as it is the same whether you do 10 board or 1000 boards and is typically in the hundreds of dollars. There will be an NRE for the PCB, the Pick-n-place, the solder past mask, silk screen and testing setup (if you wish this option).

Check into having one place make the PCBs and another stuff the SMT parts. Or learn how to do the SMT parts yourself, 15 parts on 100 boards is not that hard of a job. My brother manufactures small runs and does all the SMT assembly himself in his basement.

Where I work any bare PCB made has a minimum cost of $500-700, regardless of the size, #layers or quantity. This is due to the setup cost of making the board which is fixed if we have 1 made or 1000 made. We typically buy a minimum of 10 PCBs for engineering since it tends to cost the same for 1 to 10 PCBs.

Another issue you probably have run into is many boards assembly houses do not like doing small orders and then charge a lot to run these. There are many smaller shops but they are a little harder to find.

Do you know of any smaller manufactures in your area? If so, then visit them and ask where they have PCBs made and built. Other manufactures can be very helpful in referring you to suppliers and may even have in-house SMT facilities that they do not run to full capacity and may be willing to take on a few small outside jobs.

Off shore can be hit or miss as to quality. I really don't have any suggestions here except to go with your gut feeling.
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by zenwebb on Sat Jan 18, 2014 11:38 am

waltr wrote:That is a tough one for only 100 units.

Yep! But I feel like 100 is the golden amount for small-scale Makers like myself. 500 and up seems like a huge jump, and I have no clue whether my board will be that popular - quite the financial risk for me. Plus, I'll be using Kickstarter to raise funds for manufacturing, so a smaller run is less risky in terms of generating demand.

Are you looking to have both the PCB made and installing all the SMT parts?

Both. PCBA. PCB fabrication is very easy and cost-effective for me through places like Seeed Studio and similar competitors (iTead, etc).

Are they to also buy the parts?

All of the quotes I've received don't include part costs, but do have a part handling fee based on part values.

Were the quotes you get broken down to show the NRE (setup up) cost and then the cost per unit?

Yep. Seeed's quote had an overall setup cost of $500, plus a couple hundred for the work. As an example, I received a quote from AAPCB for $3368.62, with NREs for stencil ($100) and setup ($50). I feel like there must be a lot more going on there to drive the cost up so high. None of the quotes I've received have cost per unit.

Or learn how to do the SMT parts yourself

I assemble the prototypes myself with no problems w/ a soldering iron, and have had some bad experiences with trying to do reflow myself at home. I have since learned about OSHStencils, so I feel like I could very easily handle the PCB fabrication, stenciling, paste application and reflow, but I'm a bit cautious about the physical labor involved in manually unpackaging and placing every part onto the board. I'm not so much worried about losing money on my time, but rather the sheer physical strain of assembling 100 boards by myself - I'm concerned it would take weeks or months to do it by myself, and I am a full-time grad student in my last semester before graduation.

Do you know of any smaller manufactures in your area?

Nope. I live in a small, somewhat isolated town in Nebraska. There are a handful of large machine shops, but they tell me they are booked for months ahead of time for large factories in the area, and can't afford to do small jobs.
Jason Webb - grad student, creative technologist, OSHW engineer
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by vputz on Mon Jan 20, 2014 5:14 am

Right there with you, Jason (and a shout to a fellow NE citizen, though I haven't lived there in years).

I'm in the same boat, though; got a tiny little board with 19 components that I've sold about 20 of with zero advertising, so I felt like doing a PCBA run of about 100 would be a "next reasonable increment" as after squinting with tweezers building even a small batch of 10 is annoying and tiring for me. But the lowest quote I found was around $1200 for JUST the assembly (I provide all parts and PCBs), which makes it a great deal less profitable and more risky.

But as long as my volumes are low, it's just massively cheaper to build them myself. If I was selling through-hole kits, that'd be easy, but when offering a PCB through-hole kit and an SMD complete board, I've sold 20 SMD boards and 1 kit, so it's pretty clear where the consumer preference lies...
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by lyndon on Mon Jan 20, 2014 1:03 pm

zenwebb wrote: I'm concerned it would take weeks or months to do it by myself, and I am a full-time grad student in my last semester before graduation.


That seems unlikely. Have you timed yourself making a few boards? I asked a question about this around a year ago because I felt that I was too slow. Back then I timed myself at a worst case average of about 30 seconds per component when depositing paste by syringe and placing components with tweezers or vacuum with a pretty high mix of parts: different resistors, capacitors, about 2 dozen LEDs, multiple fine pitch IC's etc.

That's about the worst case, so your board would take less than 10 minutes to populate by hand. That time drops significantly if you paste up by stencil.

For a simple board, my SWAG to do 100 probably be about 10 very boring hours. I've assembled thousands of through-hole boards by hand. It sucks ;-)
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by zenwebb on Mon Jan 20, 2014 4:40 pm

I tried using a syringe and a hot plate a few times, and had terrible results each time, definitely not going to do that again! I would plan to use stencils from OSHStencils, and a DIY reflow oven. On a related note, I was wondering if it is worth it to invest in a Chinese reflow oven (like the "T-962" on eBay), or a DIY toaster oven conversion kit.

I feel like it would take weeks to actually get a batch of assembled and tested boards, because of the overall time of everything. Applying paste, placing parts, reflowing (only a few at a time) and testing the boards afterward. Will paste dry out if left exposed to the air for a day or so? If so, I will need to only stencil and place parts onto as many boards as I can fit in the oven at once - seems like that could bottleneck things a bit.

That being said, I am definitely much more interested in self-assembling the boards. That could help me quite a bit to increase profit (which is very thin as it is).

But like I said, I am a full-time grad student in my last semester before graduating (and possibly having to relocate). I am trying to be extra cautious of anything that would force me to put in a ton of labor that I may not be capable of doing.
Jason Webb - grad student, creative technologist, OSHW engineer
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by lyndon on Tue Jan 21, 2014 7:38 am

I hear a wide range of opinions on the T962, so I haven't pulled the trigger on one yet. My gut tells me that it's typical low-cost import quality: it works well enough for hobbyist use, but far below the quality of more expensive units. I use an old toaster oven and control it manually, but I generally don't make more than 10 boards at a time. I have left boards pasted and unpopulated for an hour. Longer than that and I'd worry about contaminants getting into it. I don't know what the maximum walk away time is
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by vputz on Tue Jan 21, 2014 4:46 pm

My local hackspace has a T-962, and it beats the heck out of my homemade hot plate + reflow controller (using an IR sensor to measure the hot plate temp). It's probably as you say--fine for hobbyists and low volumes but nothing particularly special. The boards did come out at a higher quality than my hot plate, but not massively so. In the future, I'll likely use the T-962 just because it required less monitoring and could do more boards at once, but if I was seriously serious about this I'd probably pick something better. It serves my needs.
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by lyndon on Wed Jan 22, 2014 8:45 am

Thanks for another datapoint on the T952. BTW, are you the same vputz that did a P-S-P study?
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by vputz on Thu Jan 23, 2014 1:57 pm

Heh--haven't thought about THAT in a while. But yeah... that, the shareware game Flynn Sprint, the mid-90's game programming library YakIcons, now playing with hardware in the Orbotron 9000. Lots of little background projects; how'd you run across the P-S-P study? (and why the devil is the Personal Software Process considered a bannable spam abbreviation?)
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by lyndon on Fri Jan 24, 2014 12:00 pm

Sometimes I google unusual usernames to see what else they've done ;-) I also spent some time looking up the Orbotron. That thing could be an interesting interface for a robot!

It caught my attention because I'm trained in P.S.P (Advanced) and as a TSP team leader and our day-to-day software development follows TSP/P.S.P practices. I think the forum doesn't like the abbreviation because it can be spam for PlayStation Portable.



vputz wrote:Heh--haven't thought about THAT in a while. But yeah... that, the shareware game Flynn Sprint, the mid-90's game programming library YakIcons, now playing with hardware in the Orbotron 9000. Lots of little background projects; how'd you run across the P-S-P study? (and why the devil is the Personal Software Process considered a bannable spam abbreviation?)
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by vputz on Tue Jan 28, 2014 4:05 pm

It was a fun project--and really brought home to me the effect of language choice on the process of development (and the power of functional languages and design by contract).

The Orbotron turned out well actually; if I can get interested in writing more broad-based firmware for it (maybe to handle a few more devices, etc) and get a more general-sounding name, I may actually try and get more attention and see if I can drop the price and sell a few more (thus my interest in this thread). Bit of a flail really, learning all this, but good for me.
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by mikeprevette on Thu Feb 27, 2014 1:46 pm

damn just saw how old this thread was

100 is really not that bad. This summer I did 120 little boards of a mix of through hole and SMD by hand and I was done in a few evenings. Had I wanted to I could have powered them out in a weekend no problem. The key is to group repetitive tasks and do them in batches of like 10-20 and take a break. IE: All resistors on 20 boards |break| all caps |break| all MCUs etc
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by felis on Thu Feb 27, 2014 3:04 pm

If you want to do small batches of inexpensive boards the only way to make a profit is to do it yourself. Learn to reflow, this skill doesn't require much effort to learn and if you're a grad student you are more than capable of it. Outsourcing PCB assembly starts making sense from ~1000+ pieces (and even then I prefer doing it myself albeit not manually).
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by bigmessowires on Wed Mar 12, 2014 12:20 pm

I've been looking at this myself recently, for an even smaller run of quantity 50, and found a couple of good options.

1. Smart-Prototyping (China): http://smart-prototyping.com/Prototypin ... rototyping
They will make the PCBs, procure the parts, assemble everything, and also flash it and test it if you wish. The cost for assembly is determined by simple formulas shown on their web page, so you can calculate it yourself before even talking to them. For my medium-complexity board with a mix of SMT and through-hole parts, the cost of assembly for quantity 50 was $7.75 per board. That includes the stencil, but not the cost of the PCB itself or the BOM parts. There is no NRE fee or other setup fees. But they charge an extra 4.4% on top of the quoted price to cover PayPal fees, so it's really like $8.09 per board. This price is with no testing.

2. Microsystems Development Technologies (California): http://msdus.com
Same as Smart Prototyping - they make the PCBs, procure the parts, assemble, and (optionally) test. For my board in quantity 50, the cost of assembly was about $14 per board. Hard to say exactly as they quoted a total price per board, without separating out the PCB, BOM, and assembly costs. This includes a $250 NRE free. For quantity 100, the assembly cost dropped to about $8.40 per board. Again, this price is with no testing.

I chose to go with Microsystems Development Technologies, even though they were more expensive, because they're local to me and the owner was pretty helpful in answering my noob questions. But Smart-Prototyping was also pretty good about answering questions, and I might go back to them in the future if I need more larger assembly runs.

My advice is to be prepared when you talk to manufacturers, and don't waste their time. The overhead of exchanging multiple detailed emails with you to answer questions could easily eat up their entire profit on a small order. Make sure you have a detailed bill of materials with the manufacturer's part number, package type, voltage ratings, tolerance, and Digi-Key ordering link for every part, so they don't have to waste time trying to understand what you intended. I think you'll get a better reception that way.
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