Which manufacturer can do pcb and smt soldering for small sampling volumes?

william chan

Hi,

I have designed a board with some SMT components like Prop QFP, 24LC256 SOIC EEPROM, FT230XS, USB Mini-B SMT connector and MicroSD holder.
I need a sampling of 9 pcs for testing.
I know I will not be able to hand solder the samples, especially the FT230XS chip.

Which manufacturer is willing to quote for a sampling of 9 pcs only?

LoopyByteloose

You are in Hong Kong.. right? I suspect that there are local outfits or ones in Guangzhou that would be happy to help. Years ago, they advertised for US business in Nuts and Volts. I need to dig through my old copies to get you a name.

Other than that approach...
I believe that Futurlec and Sparkfun have both used mainland Chinese board makers for customer ordered board. I found the prices through Futurlec to be about the same as direct ordering. And they will do partial or full assembly. They even have the chip inventory on hand.

http://www.futurlec.com/PCBService.shtml

I will try to give you some other names later after digging through old Nutz and Volts. I may have to go back 5 or more years to find the ads.

Heater.

William,

Coincidently I just came across this great video by Dave Jones of the Electronic Engineering Video Blog http://www.eevblog.com
that discusses issues related to designing a PCB for production or prototype run.

http://www.youtube.com/watch?v=VXE_dh38HjU

No mention of shops that can do that but you may find it useful anyway.

Leon

I've used these people for prototype assembly:

http://www.asktechnology.co.uk/

Prices were reasonable and they did a very good job.

LoopyByteloose

These people are producing in Shenzhen, China, with a sales office in the USA.
http://superpcb.com/services.html

I am sure there are others, but you may have to search for contacts in Chinese, or even visit Shenzhen to meet face-to-face.

http://www.made-in-china.com/products-search/hot-china-products/Printed_Circuit_Boards.html

Years ago, I made a board in China and was very happy with the price for a run of 25 boards (about $4/each). We did have some delays due to the need to verify information, but I'd much rather have the delays than to receive the wrong item. At that time, I did look into producing them in Taiwan and the person I talked to wanted about $250 USD for a small run done locally. My impression was that if there was any production in Taiwan, they were doing big runs and not wanting to deal with sampling runs that might or might not reorder.

I am not having much luck going through an August 2004 or May 2007 Nuts & Volts. But Googling "printed circuit boards in China" provides a lot of leads. I have more magazines, but the company English names may have changed from then.

Tubular

Might be worth talking to SilverCircuits in KL because they do lots of proto work. I would expect they'd know someone locally

william chan

I checked out superpcb.com and silvercircuits.com websites but both does not mention anything about board assembly, only pcb fabrication.
Most PCB manufacturers I know do not do assembly work as they deem it too risky. For example, what if the board doesn't work?

T Chap

Which package of the FT did you use? With a stainless stencil and an oven, this is not a complicated board to make at home. 9 pieces is often a pricey run. You spend big bucks to make 9 boards that may have a fatal error on the pcb...

LoopyByteloose

Futurlec will likely do it. But the reality is that the boards will be made in GuangZhou and someone will just be handed the 9 boards and told to solder and test according to your specifciation. I doubt if this is going to be an automated assembly. They do say 'batch sizes for assembly start at 50 items'... so you may pay costs for 50 even if you only want 9 assembled.

Anything below 1000 or more boards to assemble is likely a low-volume assembly... labor intensive and more costly.

You might Google "circuit board assembly services" for companies... and add 'in China' if you want to see local services.

http://futurlec.com/BoardAssembly.shtml

http://www.made-in-china.com/products-search/hot-china-products/Assembly_Circuit_Boards.html

william chan

As you can see here the FTDI chip has much closer pitch than the Propeller QFP chip.

I don't have a stencil printer so I don't think I can stencil align such a small board by hand.

This board is still work in progress. It is supposed to plug directly to PropCam-DB.

T Chap

You can make a stencil printer from parts found anywhere. With a frame-less stainless stencil, you can tape one side of the stencil down on a table and move the part around under it. I use silk screen hinges on my various stencil frames. They are about $20 each hinge. Mount them on anything. Then have a movable section that the PCB sits on top of. Slide the movable plate around to line up the board. I just put a board with an FT232Rl on it, lining it up took about 5 seconds. There is no reason to send that board out for fabrication. It may be helpful to have a hot air rework station(find anywhere online for $100) in case you need to move a part around and practice. Solder bridges are removed easily with flux and a fine tip soldering iron and a little practice.

SRLM

I'd build it myself. Like T Chap, I built my own stencil "frame". There's a simple one here:
http://forums.parallax.com/showthread.php/149285-QFN-chip-solder-points-on-both-bottom-and-edges?p=1197786&viewfull=1#post1197786

And a slightly nicer one here:
http://forums.parallax.com/showthread.php/149285-QFN-chip-solder-points-on-both-bottom-and-edges?p=1200517&viewfull=1#post1200517

With these I was able to reliably stencil and solder parts with 0.4mm pitch.

It will probably take you 3 or 4 boards to get the hang of it, but that's likely to be much cheaper than sending it off to be made.

tonyp12

You don't say what part of the world your want this done, as having it done in the same country as yourself is preferable due to shipping cost and shipping time and customs etc.
You can make 9 units in a day.

Order 3 sets of the same board from Oshpark.com = 9 boards.
order 1 stencil + jig from oshstencils.com, and paste from digikey.com

Get helpinghand+magnifier: http://www.radioshack.com/product/index.jsp?productId=31849356
With a steady hand use tweezers to place your parts on the solder pasted board.
In the oven for 7minutes, done.

LoopyByteloose

I may have been wrong to presume Hong Kong. I see that his links are in Malaysia.

Maybe Malaysia or Singapore would be a good place to get this done.

Tubular

william chan wrote: »

I checked out superpcb.com and silvercircuits.com websites but both does not mention anything about board assembly, only pcb fabrication.
Most PCB manufacturers I know do not do assembly work as they deem it too risky. For example, what if the board doesn't work?

Sorry I meant call/email them and ask who they would recommend for assembly. So I did this for you and they recommended Silvtronics in KL. They may be related entities, I don't know. Their address is different

Their online quote tool suggests assembly of 9 boards, each with 8 smd components, would be US$146. You would hand solder the 2 through hole parts yourself. Or you could pay them about an extra $50 to take care of that.

Lawson

Have you seen the old SparkFun SMT soldering tutorials? They show you how to do surface mount soldering with just a fine tipped temperature controlled iron, tweezers, flux and solder-wick. After reading them a few years back, I jumped in and tried it myself. Now I actually prefer SMT parts because they are quicker to solder down and take up less space. (as long as the parts have leads...) By now, I'd guess I could assemble a board like yours in about a half hour. (the first board will take longer ofc.)

I've also had good luck manually applying solder-paste with a syringe. I then re-flow in a toaster oven. The chips usually have a solder bridge or two, but solder-wick cleans those up quickly.

Marty

LoopyByteloose

I guess we have all decided that anything less than 50 boards is a DIY assembly... just not cost effective for a business to do.

One might find an electronics student that desires to provide the service cheaply at a local university.. but that is a bit of a hustle.

shimniok

I'd suggest a cheap reflow station (Aoyue is what I use but there are others) and do it yourself. Forget stencils, add some solder to the pads with an iron, treat with Kester 2331ZX solder pen, use SMT tweezers and reflow them yourself? I've built hundreds of boards this way with 0603 parts and 0.5mm pitch pins. SOICs and QFPs seem to work best if done with an iron. If I can offer any tips let me know

william chan

Hi shimniok,

Your suggested method is very interesting and simple.
Will be solder placed on the pads make the surface uneven for placement of parts?
How long do you put them in the oven?

shimniok

You want to level out the amount of solder between related pads, e.g., between 2 pads for caps, resistors, beads, diodes, LEDs.

Then use the hot air rework station I mentioned. The solder melts and the parts drop down to the PCB while the solder wicks up onto the device pins/pads.