Feasibility of a small run/prototype SMT assembly service

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digistump
 
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Feasibility of a small run/prototype SMT assembly service

Post by digistump »

As a long time reader (first time contributor) of this forum (and a big fan of adafruit) - I thought this might be a good place to get some feedback and gauge some interest on an idea that I've been working with some folks on for a while.

I think anyone making a SMT based prototype has wondered why assembly can be so expensive, ok maybe not everyone, but I hate doing my own SMT soldering, even with all the tricks and good equipment. Obviously automated assembly for a few units is so expensive because of the setup costs - just looking at all the trials and tribulations with pick and place machines on this forum is a good indicator.

This got me to thinking what would it take to provide the SMT assembly service equivalent of OSH Park (formerly dorkbotpdx) or BatchPCB besides a really patient operator?

After some serious thinking, researching, talking to vendors and operators, and general pricing and exploration of all the details here is what we've arrived at:

PCB fabrication, solder paste application, SMT assembly (a combination of PnP and manual), and reflow soldering for $10/sq in(plus parts) for 2 boards (so a 1x1 board would be $10 for two copies plus parts).

Obviously this price blows existing prototype assembly companies out of the water so here are limitations we've arrived at:
  • Eagle and KiCad libraries would be provided for download of 50ish+ most common parts (determined by vote?) sorta like Jellybeans - Many resistors, caps, a few voltage regulators, maybe a few ICs - these parts would be preloaded on a pick and place reducing setup time. These would be priced at digikey or better price.
  • A variety of popular but lesser used parts placed for free. Again these would be priced at digikey or better price.
  • Custom parts for $1 per part - you send in the parts we don't start your order or charge you until the part is received.
  • Any through hole components would be left for the buyer to assemble.
  • Discounts once the total of your copies exceed around 200 sq inches (we'd have a simple calculator to tell you how many copies of your board this is).
  • 0603+ and no fine pitch/BGA to start - but all equipment would support it.
Here are our feature ideas, you know beyond SMT assembly!
  • Website that accepts Eagle Board files, or Gerber+Drill+Centroid (OSH Park is our inspiration here of how a PCB order should work)
  • Website shows preview and totals part costs, allows you to define any custom parts to be sent in.
  • Live status on website and turn around estimate based on current queue.
  • All USA based from PCB to assembly (assembly here in Washington state).
  • All order shipped out priority mail ($5 per order regardless of number).
  • Open, transparent, documented process and business (we think it'd be great to have competitors!)
  • Extra raw PCBs (we'd order 3 at least to ensure we have 2 good ones) would be thrown in the order, maybe random rejected parts from the PnP as well
We come from backgrounds in programming, pcb design, and industrial equipment operations. We've put a huge amount of research into this, including working up custom options with Pick and Place manufacturers, PCB fabricators, etc and have the capital, space, multiple 220v hookups, and passion to make SMT assembly into a truly accessible service - we're thinking about using kickstarter to gauge interest/reserve pre-orders.

Please by all means - rip apart our idea, give any feedback you have, or any suggestions!

Thanks!
Erik Kettenburg

mikeselectricstuff
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by mikeselectricstuff »

PCB fabrication, solder paste application, SMT assembly (a combination of PnP and manual), and reflow soldering for $10/sq in(plus parts) for 2 boards (so a 1x1 board would be $10 for two copies plus parts).
I think actual costs are too complex to simplify down to a cost/square inch. Things like component mix and density have a big effect
Obviously this price blows existing prototype assembly companies out of the water
There are hundreds if not thousands of contract assembly companies out there, so if there was a viable way to provide a cheap low volume service I'm sure several of them would be doing it by now.
Eagle and KiCad libraries would be provided for download of 50ish+ most common parts (determined by vote?) sorta like Jellybeans - Many resistors, caps, a few voltage regulators, maybe a few ICs - these parts would be preloaded on a pick and place reducing setup time. These would be priced at digikey or better price.
Can you afford to do ordering, stockholding and inventory management etc. and still sell at DK prices?

A library provided by the assembler is a good way to streamline the P&P setup process - orientations correct etc. but to be generally useful I suspect that library would need to be a lot bigger than 50ish parts.
A variety of popular but lesser used parts placed for free. Again these would be priced at digikey or better price.
So my board has 2000 of these parts - would you still place those free?
Custom parts for $1 per part - you send in the parts we don't start your order or charge you until the part is received.
Probably too simplistic - is that $1 per part type or per part placed?. You also need to factor in spares for tape leaders, mis-picks, drops etc., and time to teach the vision for a new part type.

Any through hole components would be left for the buyer to assemble.
probably sensible, at least initially. If it takes off you could consider getting a flowsolder machine
Discounts once the total of your copies exceed around 200 sq inches (we'd have a simple calculator to tell you how many copies of your board this is).

Again. area is too simplistic - the machine time to place a given area varies hugely

0603+ and no fine pitch/BGA to start - but all equipment would support it.
You need to have a good,reliable process from the start, and 0.5mm pitch/0402s are routine - probably the only difference is paste print quality.
Here are our feature ideas, you know beyond SMT assembly!

Website that accepts Eagle Board files, or Gerber+Drill+Centroid (OSH Park is our inspiration here of how a PCB order should work)
May be worth thinking about how you can support other PCB packages in a way that streamlines your process - gerber plus pick/place locations still has issues e.g. orientation. Maybe a simple well-defined job file format that people can contribute converters for different PCB packages.
Website shows preview and totals part costs, allows you to define any custom parts to be sent in.
An accurate graphic preview would be really good, in particalar to confirm orientations.
Live status on website and turn around estimate based on current queue.
All USA based from PCB to assembly (assembly here in Washington state).
All order shipped out priority mail ($5 per order regardless of number).

PCBs are heavy.. you don't want to be losing money on postage
we're thinking about using kickstarter to gauge interest/reserve pre-orders.
This is the sort of project that lots of people will think is a good idea, but has a very serious danger of not being viable for possibly unforseen reasons.
What is your plan for solder-pasting? I think this could be the biggest hurdle. I don't think stencils are viable, as although you could do large multi-job panels, you will probably end up needing too many feeders for the component mix on a mised panel.
Dispensing is probably not accurate and/or fast enough.
Ultimate answer is probably the Mydata solder-paste jet printer, but I think these are rather expensive.

digistump
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by digistump »

First of all - thanks for the feedback Mike! Many of the things you mention are things that have been debated, calculated, etc - but you certainly hit on several things we need to keep re-considering and some new things we hadn't considered. Thanks for taking the time to respond!

A few responses with the thoughts I've had on the points brought up.
I think actual costs are too complex to simplify down to a cost/square inch. Things like component mix and density have a big effect
That's true they are too complex, the idea isn't that every board is profitable, but that overall the boards are profitable (or at least mildly profitable). Every time we went to a more complex pricing we came back to this - the price is geared towards small boards with high density - large boards get expensive fast, which is ok because we are aiming at hobbyist who just need a couple smaller boards (similar to OSH Park). Density is somewhat limited by the limited part libraries/pay per part for non library parts. We would certainly have some limitations built into our web interface (I'm a programmer by trade, so many obstacles would be overcome/caught by the software) - I'm sure there would be a size limit and a parts per sq in limit or up charge - but these would be aimed at a small minority of boards that wouldn't fit the aim of the service.
There are hundreds if not thousands of contract assembly companies out there, so if there was a viable way to provide a cheap low volume service I'm sure several of them would be doing it by now.
To be clear - we don't plan to compete much with them - just like PCB pools broke the pricing of the long established expensive PCB fabricators, we'd be using tricks (paneling, custom software, slower turn times, no testing, etc) and appealing to a much more specialized market. When you get to boards like 4"x4" it actually isn't that far from existing prices ($160 for two boards).
Can you afford to do ordering, stockholding and inventory management etc. and still sell at DK prices?

A library provided by the assembler is a good way to streamline the P&P setup process - orientations correct etc. but to be generally useful I suspect that library would need to be a lot bigger than 50ish parts.
If we are only stocking 50-100 reels (ok more than that, several of each reel) - we have the space for it, the software end of managing it, reordering, etc is the easy part for us - and what I should be clear on is we'd be selling per part used at DK single unit prices, so essentially we'd be paying those small costs by the difference between reel pricing and single unit pricing.

Is 50 parts enough? We keep coming back to this question. Of boards I've made (Arduino sheilds, Arduino clones, PID controllers, Sensor arrays, etc) 90-99% of the parts are common to about 20 parts, most can be found on other peoples lists of "Jellybeans" including the one on the wiki here. Again the idea is not to serve everyone but to serve the core hobbyist group, if people are laying out Class D amplifiers, they probably would still need to assemble all or most themselves, or it would be very pricey for use to do it and we'd keep it pricey because that is not our aim. I certainly would love to here from some more people on this - is 50 enough? 100?
A variety of popular but lesser used parts placed for free. Again these would be priced at digikey or better price.
So my board has 2000 of these parts - would you still place those free?
No - again the software would limit/up charge for things over the standard weekend warrior type assemblies, this also would not be a huge part pool - 10-20 parts maybe, again of limited use to more advanced hobbyists but great for the beginners using all the popular parts/designing to these parts.
Probably too simplistic - is that $1 per part type or per part placed?. You also need to factor in spares for tape leaders, mis-picks, drops etc., and time to teach the vision for a new part type.
Per part placed on the two boards, or per part per board, none of this is exact yet - but these would be manual placements (or vacuum assisted) and we would likely ask for three parts for each two boards and ship back the extras - again maybe not ideal if the chip costs you $20, but for our other 1-5% of chips not in our general library we think this would work for many hobbyists.
probably sensible, at least initially. If it takes off you could consider getting a flowsolder machine
Certainly! I don't mean to limit our possibilities only our starting specs.

Discounts once the total of your copies exceed around 200 sq inches (we'd have a simple calculator to tell you how many copies of your board this is).

Again. area is too simplistic - the machine time to place a given area varies hugely

That's very true - again we'd want to build some software limitation in for sure, if you want 500 boards we aren't your assembly house (in fact I think we'd auto suggest a good one for you in that case). But at 200 sq in that's $1000 (two copies of 100 sq in) already, we could certainly move more towards from the savings in shipping, setup etc, since at that point we are running multiple identical panels.
0603+ and no fine pitch/BGA to start - but all equipment would support it.
You need to have a good,reliable process from the start, and 0.5mm pitch/0402s are routine - probably the only difference is paste print quality.
Routine yes, but still in our experience finicky with new software, machines, operators, etc. This would be a limitation we'd want to get rid of ASAP, but it would help us get up and running faster. Worth noting that these panels would be running on 7722FVs and similar, not the really end PnPs.
May be worth thinking about how you can support other PCB packages in a way that streamlines your process - gerber plus pick/place locations still has issues e.g. orientation. Maybe a simple well-defined job file format that people can contribute converters for different PCB packages.
That is such an excellent idea - I just had a "duh" moment, we'd process eagle brd files with a custom ulp, we could likely convert kicad on our end too, and it'd make sense to open source our format so people could come up with other converters. I think the web interface could go a long way here too, showing the layers and placements and having the user confirm them, especially when gerbers+XY were used.
An accurate graphic preview would be really good, in particalar to confirm orientations.
Yes! I think this would be nearly as important as a reliable machine setup! We would not be able to skimp at all on the web interface/preview, and that's OK because conveniently that is my day job!

PCBs are heavy.. you don't want to be losing money on postage
Good point, the aim here is to keep shipping options simple, likely the software would let you know when you've jumped up to the medium flat rate box and change price accordingly.

This is the sort of project that lots of people will think is a good idea, but has a very serious danger of not being viable for possibly unforseen reasons.

What is your plan for solder-pasting? I think this could be the biggest hurdle. I don't think stencils are viable, as although you could do large multi-job panels, you will probably end up needing too many feeders for the component mix on a mised panel.
Dispensing is probably not accurate and/or fast enough.
Ultimate answer is probably the Mydata solder-paste jet printer, but I think these are rather expensive.
We drool over things like the Mydata solder paste printer! We are exploring both stencils (laser cut in house, probably from kapton/mylar) and paste dispensing, since we'd be doing panels and all panels would be the same size, setup for stencils wouldn't be too difficult, but would get increasingly less accurate with fine pitch, certainly having a limited parts library would help get this right, but headaches caused by custom parts might have to be taken into account in the custom parts price. Dispensing is one of those things that looks perfect for this sort of thing, but doesn't seem to be quite there technology wise - needless to say I take a keen interest in the micro dispensing thread here!

Again thanks for the feedback and ideas! I agree it is an idea that has serious danger of failing, but if we could make it a success (even a very modest one) I think it'd further open the electronics hobby for people like us and maybe help some more people make the transition from breadboard to prototype to production.

Thanks Again!
Erik

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alphatronique
 
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Re: Feasibility of a small run/prototype SMT assembly servic

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digistump
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by digistump »

Marc,

Thanks for your feedback - and all your posts - I've carefully followed many of your SMT posts and am fascinated by your customization of older machines!

We're looking at an investment more around 100k$, so that is not a problem.
The other issues you bring up are great ones, and you certainly have the experience to go with it -
I think one of our big goals would be to minimize design issues with very intelligent software, essentially instant DRC for part placement data, paste layer, etc when the upload the files. Footprints would for the most part be limited to the libraries we provide and machine setup would be reduced by not changing any feeders or parts (given a preset part library).
Fidcials would be part of the panel, and added automatically when designs are merged on to a panel.

Thermal mass difference is certainly an area we not only need to study more, but need to come up with a good solution for. Any one have an idea how we might address this - maybe software that sorts boards to panels based on total area of copper?

While we'd certainly try to assure the quality of our work, we would not guarantee the boards function, much like prototype PCB manufactures - again this is aimed at hobbyists not production.

Of course if we are able to do this quantity would make us more money, thankfully while breaking even is necessary large profits are not!

Thanks again for your feedback and for echoing some very real concerns! and keep up the great work with your PnP machines!

Rochey
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by Rochey »

$100K!!!

Please put a real world business plan behind this.
I paid around $9K for my old ECM93 pick and place. I could have done a lot of small PCB+Assy runs in China for the same price.
I got the pick and place, because I enjoy the manufacturing side. I didn't get it to make a massive profit.*
*don't tell my wife I said that.

Even at $10 per square inch (that's $6.70 after you pay tax), you'd need to sell ~15,000 square inches of assembly, just to pay for the machine, never mind labor etc.

You may want to start smaller, get profitable, then expand.

/R

digistump
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by digistump »

Thanks Rochey! solid advice and perspective - $100k is available capitol not what we plan to drop on machines - and as you noted a solid business plan is a must - hence asking questions, getting feedback, and all the research not reflected in my ramblings here - stating our available capitol was not to show we were fools (we very well may be though!) but to show we are serious and not hoping to start a business on $1000 and a radio shack iron - I've run some successful companies and helped launch several startups, don't worry if 100 people say "that's cool do it" we won't run out and buy the first machine we see :) Also all business plans have to be approved by my wife, so that means they better be pretty sound!

We're calculating 10k sq inches to break even on initial investment with PCB manufacturer and taxes included in that number, not including labor - so that could mean 500-1000 panels (well 1000-2000, but 500-1000 different ones), we'd likely start with a queue and a limit based on the number of panels we can do per day and be very upfront about lead times.

Thanks for the caution - we could make 10s of thousands of our boards for the price of the equipment - and very well based on the feedback on this thread so far it might not be viable, but we sure are going to keep trying to figure out if we can make it viable, simply because we believe it is a service that is needed and would contribute greatly to the hobby electronics world - after all we can't imagine if BatchPCB/OSH Park had never come along and made prototype boards dead simple, dirt cheap, and relatively fast for the price.

Thanks again!

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Re: Feasibility of a small run/prototype SMT assembly servic

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digistump
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by digistump »

Certainly Marc, pick and place and a good reflow would both be needed.
We would leave thru hole up to the customer to do themselves, I realize you couldn't do that in your business model, but as we only want to offer a hoobyist service and not a production one I think most hobbyists/prototypers would find it more than acceptable to have to due thru hole components themselves. We're lucky enough to have the laser cutter.

Your experiences certainly make me think there is no viable business in short run PnP, and I may be naive but it seems like a standard part library could over come many issues, and the wrong part/footprint/etc issues would fall more on the hobbyist submitting the design (not that we wouldn't want to help when possible). I think it would be very important to make it clear that the hobbyist using our service was responsible for their design, we certainly wouldn't be offering rework on design mistakes, after all I'm not going to ask OSH Park to remake my boards because I routed them wrong.

By having a standard parts selection cut-tape, feeders, etc issues would be greatly reduced - we'd only be running full reels and we know the costs to buy all the feeders - they sure are expensive aren't they! Luckly most popular parts are 8mm which are the cheapest.

I have no doubt humans making low wages would be more flexible and practical, but humans making fair wages to operate machines is much more appealing and part of what I'd like to sell about it - that and the fact that nothing would be made in China or other low wage countries.

I'll keep that in mind about old machines, I think we're mainly looking at new ones, including the 722FV that's so popular on this form.

Thanks again for the feedback! Please don't take my determination to figure out how this could work as a lack of appreciation for your stories of caution!

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Re: Feasibility of a small run/prototype SMT assembly servic

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digistump
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by digistump »

Marc,

I've followed the posts on your mydata machine, that was quite a task getting it in there - my space for equipment is also my basement, unfortunately it is even less accessible, which would be the appeal of a smaller lighter machine, though I certainly am not ruling out a dedicated building or running 220 to my shop.

Have you worked at all with using X-Y data for the PnP or do you always just program the machine directly/use teaching mode? If you have, what has your experience been when the X-Y data is correct and accurate?

I really like the semi automated assembly idea - unfortunately it is not for me, as I rather not have to hire a staff and deal with all that comes with it. Really cool idea with the galvo though!

I have a few boards getting ready for medium run production, I'm thinking perhaps I'll use the assembly of them to justify the PnP purchase (afterall even if my idea failed it'd be great to have a PnP!) and then see if I can write custom software to make it practical/explore the limitations of it.

Thanks again Marc!

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digistump
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by digistump »

I had a message asking for an update on all of this so I thought I'd provide one for anyone watching this thread:

I had to put this idea on the back burner due to the success of another project - the Digispark: http://www.kickstarter.com/projects/dig ... -dev-board

But this project has provided the capitol for me to setup a SMT assembly line (we are having the Digisparks contract made, but hope to make them in house after the first run as well as many other products when we open our web store). As part of our web store we will be offering custom laser cutting, a PCB pool service, and lots of neat boards, kits, etc - so naturally we hope to add a small run/prototype SMT service to this eventually - so the idea is still alive and well, and once we have our SMT assembly line setup I'll start playing with this idea again and be able to test feasibility in a real environment.

Thanks everyone for all the great info shared in this thread!
Erik

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alphatronique
 
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Re: Feasibility of a small run/prototype SMT assembly service

Post by alphatronique »

Hi

that good ;-)

i will post i coming week a small hack to mydata machine
for remplace computer whit mutch more powerfull pc
that not make machien faster since pc was only for GUI and verry hight level task
but it will fast the webserver ,permit to use solid state drive ,usb mouse / keyboard
(original pc was pentium 100 to 233mhz so it real shame)

so any way i hope you will have great sucess to setup your shop
and if need will happy to help

Best regard

Locked
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