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Low volume prototyping

Views: 6153

Piet Brandsma

#42546

Low volume prototyping | 4 July, 2006

Dear all,

I am one of the founders of a small company doing electronics design + embedded software. Currently our prototypes are using increasingly complex smd components. When we started we mostly used atmel cpus, but now we are starting to use fpgas as well. As a result it takes much more time to finish a prototype. Also the components (like fpga chips) are getting more expensive which amounts to the costs when a mistake is made.

So now we are looking around to see if it is feasible for us to a.o. purchase a (second hand?) (semi)-automatic pick&place machine. We have little experience with automation of this work. My question is: What kind of setup do I need to increase the speed of prototyping and small volume production? What will the price range be of the needed equipment? Your opinions are greatly valued.

regards,

Piet Brandsma

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Rob

#42548

Low volume prototyping | 4 July, 2006

Hi Piet,

We looked into this too at some length (we do a lot of FPGA and 16 & 32 bit micro designs) and every semi auto machine we checked out was to be fair, crap. Especially on the number & type of devices you could sucessfully handle, set up & actual placement speed. They were basically a cross between an etch-o-scetch & a meccano set.

We are still looking for a decent low end pick & place, and will probably go with the laser alignment Quadra. (muppett easy to program, just needs a small amount of air, very low maintenance, and most importantly will fit through the door of our design lab)

What you may want to consider is going with a vapour phase reflow as you are much less likely to damage the components with excess heat, and with the larger BGA's you shouldn't get the warpage issues. It will cost you about 2-3 times what a batch oven will, but it's worth it when you consider the cost & limited number of FPGA samples provided these days.

Hope that helps,

Rob.

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#42552

Low volume prototyping | 5 July, 2006

Hi,

When I started out and we were the same we got an old MYDATA TP9-2U. It places everything, and you should be able to get a cheap one second hand, that will perform very well. They have vision as well, as an options, and that works very well. I would check that out.

One nice thing about the MYDATA we used originally, is we could not afford a tray feeder, so we put the trays on the Y wagon behind the product. Then we only needed a single 8 mm tape feeder and a vibration mag for sticks. The MYDATA is unique that it can pick components from almost anything, even lengths of tape stuck down on the Y wagon. So it's easy to get started with it.

Vapor phase is also a good suggestion for low volume, and I used a pasta cooker when I started with the Geldan fluid in it, and a small hot plate under neath. You can reflow a board the same, but you don't have the water jacket at the top to stop the vapor going to high, but you can watch the board, and then gently place the whole pot in a sink filled with cold water. That will condense everything. A glass lid paster cooker is fine, and you can get it from K-Mart. I used an egg ring to raise the board above the bottom of the pasta cooker.

So all you really need to do is buy some vapor phase fluid. I should really video this so people can see how well it works! It's just the same, and you cannot wreck the board with vapor phase.

I posted some old photos of this process the guys took in our office because they thought it was so funny doing it with a pasta cooker.

http://homepage.mac.com/grant.petty/PhotoAlbum3.html

You can get the general idea from that I guess, and it might help.

So if I was starting again with no budget, I would get a MYDATA TP series machine with some basic reel feeders, and a vapor phase pasta cooker. If you do more you can buy the real thing. Also a manual stencil printer is easy to find.

If you have a go, and get creative with some ideas to get around problems you can get started and learn heaps. It's lots of fun, and take photos so when you get big, you can look back at where you came from.

Good luck!

Grant

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Chunks

#42568

Low volume prototyping | 5 July, 2006

I agree with Grant. The MYDATA machines we had were very easy to program, adjust and as Grant states make them pick up from just about anything. The best part of them was using partial reels or strips of parts. These machine don't care about having a long leader strip to load the magazines.

I like Grants idea on the K-Mart Vapor Phaser too. Is that the George Forman model? What's that thing standing next to it? Just kidding - still think it's a great idea.

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#42583

Low volume prototyping | 6 July, 2006

Hi,

Yes, when your starting out you need to really think of tricks to get a good result, without any money. Funny when I look back!

Regards,

Grant

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Piet Brandsma

#42597

Low volume prototyping | 7 July, 2006

Dear all,

Thanks for your ideas and tips. I have been looking around to see what equipment would be good for prototyping. I found a link of a company called essemtec containing a semi-automatic pick&place machine.

http://www.essemtec.com/e/115.php

I haven't requested a quote on the price yet. I am very interested in your opinions on such a system. What should such a system cost?

regards,

Piet

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Rob

#42599

Low volume prototyping | 7 July, 2006

I HATE them. I have tried most types and am not impressed. By the time you add on all of the extras such as tape feeders, trays, nozzles, guidance, etc. you could nearly buy a used Mydata/Contact/Quadra/Versatronics/Quad/Daum which would give you proper placement & repeatability, and doesn't rely so heavily on the operator, and free's up their time elsewhere.

Costs I've been quoted vary between $10K-$17K.

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Piet Brandsma

#42600

Low volume prototyping | 7 July, 2006

Hi Rob,

That's indeed quite expensive. I had contact with someone offering a second hand and refurbished DIMA pick place machine:

http://www.exmore.com/nl/electronics/secondhanddetail33.aspx

The guy offered the machine for 14000 euro's. In this case the price difference is so small between semi-automatich and a fully automatich machine. What about the second hand MYDATA system eerlier recommended in this thread? What would be be an indication for their price?

regards,

Piet

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Rob

#42601

Low volume prototyping | 7 July, 2006

Hi Piet,

I've never used a Dima macine before, so I can't comment there. I've seen Mydata's sell for as little as 8500 Euros from customers to 17,000+ Euros from dealers, to a lot more from Mydata. A lot depends on being in the right place atthe right time (knowing who is closing or upgrading locally is a good start).

One thing you will have to think about is maintenance - a lot more can go wrong on a real pick & place.

Cheers,

Rob.

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Olas

#42609

Low volume prototyping | 8 July, 2006

Quadra Laser is really cost effective also regarding feeders, spare parts and maintenance, but I think it's not easy to found on the used market; many companies keep using it even when buying new pick-and-place equipment for large productions.

Regards, Olas

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#42613

Low volume prototyping | 8 July, 2006

Hi,

I would go MYDATA rather than an "entry level" machine.

The MYDATA low cost second hand units run the same software as their top of the line units, as well as taking the same feeders, so if you want to go faster and upgrade to a faster model, you can use the same feeders.

There are lots of MYDATA units around low cost, and they can be upgraded to the latest software if required, and run loads of second hand feeders available, because all MYDATA's run them.

Your also fully automatic, and can even conveyer the machine if you buy one without conveyers, and you get vision.

It's a much better choice. If you can, my best advice is to do whatever you can to get a mainstream machine, rather than a "low volume" machine, no matter how slick the sales guy is. low volume normally means the company never cut it in the higher end of the market, so they need to do whatever they can do sell as entry level or low volume.

Grant

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#51025

Low volume prototyping | 13 July, 2007

Do you think it would be possible to make a home made vapour phase machine for say $500. What I am think is making an 18 inch square cube type box with a transparrent lid out of s/s or copper. Fit some heating element to the base to heat the liquid. Have a mesh half way up for the PCB to sit. Basicly a big pasta cooker like you had.

Do you think it would benefit from having some water cooling around say the top third of the container ?

Do you think it would need to a means of raising/lowering the mesh in/out of the vapour ?

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#51038

Low volume prototyping | 13 July, 2007

I just got a used Philips CSM84 pick and place machine for $1500. I had to widen a doorway and rent a forklift to get it inside, as well as have it shipped. So, the total cost was much higher, but still under $10 K. I may have gotten lucky on this machine, but there are deals around. This one may have lower resale value because it is fairly big. I don't intend to do 0402 and smaller parts, BGAs, etc. at least not for quite a while. The machine wasn't calibrated too well, so I had to figure out how to recalibrate some of the settings. But, I am very happy with the way it works, now, and I have all the manuals, so I expect I can maintain it pretty much myself. I have already made a couple of new nozzles for it. It is a relatively primitive machine, all centering is mechanical, everything is operated by air, no vision, etc. (Much of that is available, this unit just doesn't have it.) It has a "beam sensor", essentially a one-pixel camera that can be used to locate fiducials.

I have placed a wide variety of parts with it, from 0805 resistors to 144-pin VQFP FPGAs with 0.65 mm lead pitch.

So, these older machines can still have a lot of life in them for small-volume manufacturing. If you are making just one, I'm not sure it really makes sense to program the machine for it. I often do as few as a dozen boards at a time, though.

What are you going to do for solder stencils and reflow? I made a laser photoplotter that takes Gerber files, so I can make my own stencils out of brass shim stock, and etch in a spray etcher like it was a PCB. I am doing reflow in a $50 toaster oven with a thermocouple controller. These results are less than spectacular, but the boards are usable. I'm still figuring out how to tweak the apertures in the stencil to get just the right amount of solder.

Jon

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#51041

Low volume prototyping | 14 July, 2007

You can get laser cut stencils in mylar 3 or 4 mil plastic sheet. This company will cut one for you form $25 for a 4 sq inch mask. See http://www.smtstencil.com/. Apparently there good for one-off to small bactch production.

Neil

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