Stencil suppliers (UK)

[Mike]

Some suppliers of stencils :
smtstencil (UK) Ultra low-cost polyester stencils for prototypes and small runs. Excellent service.
Eurocircuits (Europe) Cheapest  I've found so far for stainless stencils. Beware they ignore lines in gerbers, so must use pads for stencil frame fixings etc.!
Sparks Laser (UK) reasonably priced stencils for full-sized printers

[phonoplug]

Also PCB-Pool have a stencil service:

https://www.laser-stencil.com/

Very good quality stencils I have found. Their pooled stencil (max size 210x270mm) is well priced whereas their other services are not so cheap.

[Mike]

Pity about the 1000 pad limit though.
Especially as it can be quite hard to automatically count the pads in a gerber file....
ISTR last time I looked that it gets quite expensive for more pads & Eurocircuits worked out cheaper

[phonoplug]

True - Eurocircuits charge by area, but you cannot buy stencils alone, only with PCBs (or for a PCB previously ordered). However, their stencils are not very flat, when PCB-pool's ones are much better. I guess if you have a strong tensioning system its not such an issue.

The other advantage of PCBpool is that you can panelise several designs into one sheet. Ok so they need to be small and the total under 1000 holes, but it works for me. In that case it works out cheaper than EC and you get the flatter stencil!

Another possibility is to get a one-off PCB from PCB-pool PCB service and take the free stencil. Get the PCB with the most basic spec (no masks, no silk etc) and it can be pretty cheap. I did this with an LED board that was then panelised and had a total of about 2000 apertures in the stencil.... and it was free!

[Mike]

True - Eurocircuits charge by area, but you cannot buy stencils alone, only with PCBs

Not true - you can do stencil-only orders, the link only appears once you log in so it may not be immediately obvious. No stated limit on pads. They are more expensive than PCB-Pool when you are below the 1k pad limit

However, their stencils are not very flat, when PCB-pool's ones are much better.

not had a problem with the two I've had from them so far.

Another possibility is to get a one-off PCB from PCB-pool PCB service and take the free stencil. Get the PCB with the most basic spec (no masks, no silk etc) and it can be pretty cheap. I did this with an LED board that was then panelised and had a total of about 2000 apertures in the stencil.... and it was free!

Must look at that route next time!

Incidentally, I just found MultiPCB who also do a stencil service which looks pretty cheap : 
300mmx200mm incl. 1000 pads: €47,50
300mmx200mm incl. 2000 pads: €60,19
300mmx300mm incl. 2000 pads: €68,06
300mmx300mm incl. 2000 pads: €68,06
600mmx300mm incl. 2500 pads: €85,13
600mmx600mm incl. 2500 pads: €90,44
3-4WD standard, 2WD+80%, 1WD+120%

[Gopher]

We have used Alpha Cookson for mesh stencils in the past price was fixed, not dependent on apertures.

We now use Tecan foils on a Genesis self tensioning frame, after the initial outlay these are almost 1/2 the money of the Alpha mesh. (~£140+handling )

I can say there is a noticeable difference between using a std laser cut stainless stencil and Tecan special surface that aids the rolling action of the paste.

Freebie or "elemental" stencils that come with prototype pcb's are OK for one or 2 boards but frankly a total waste of space unless you have some way of putting them under tension. If I had a machine with a paste dispensing option I think I'd probably throw them in the bin.

[phonoplug]

Elektor sell a kit form stencil tensioner. Once you have worked out how the hell the thing goes together (instructions little more use than the 'Daily Star'), its actually pretty good. Then you can use plain cheap stencils without tensioning holes. Works for me.

I've used Alpha Fry before. They make 'industry standard' stuff - great but for the price being £160-£180.

[Gopher]

I think I've seen what you mean, often in the back of things like hobby magazines, My cheapskate method has been to tension them using sticky tape and a spare frame from a discarded mesh stencil. However .5mm and 0402 are over pasted compared to a proper one. Also proper stencil shops spot mistakes you or your customers have made in their paste layers, shrink apertures for proper gasketting and give technical advice.
I'm always stunned by the lengths some people seem to go to, to diy or bodge on some forums when they are clearly making a commercial not a hobby product, there is no substitute for using the proper equipment.
Claims of being able to hand solder SM @ 200cph for instance, wishful thinking achievable only if you know the circuit backwards and with a massive risk of dry joints, even a manual p&p pays for itself very quickly.

[Mike]

Elektor unit looks quite good, although could do with being a little bigger. I've certainly seen less good ones for more money...
Video of the Elektor frame
Product page

[SteveW]

www.smtstencil.co.uk now does A3, as well as A4 sheets, in varying thicknesses (plastic only).

PCBTrain - http://www.pcbtrain.co.uk/ continues to be my stencil supplier of choice for stainless. No pad limit, cheap & fast. They do pad alterations, and their defaults (tapering pads, dicing up big areas) seem sane.

I've also started panelising boards with half the boards flipped, so I don't have to swap stencils...

[Mike]

Yes - I mostly use PCBTrain nowadays - their "express stencil" service is the cheapest, but has a 250x350 size limit and only one thickness.
I'd prefer it if there was an explicit option to not alter pad shapes, but you can request in the comments.
BTW if you select the cheapest delivery service, I've found they still send it by next day courier anyway.

[Gopher]

http://www.youtube.com/watch?v=JWUJtmgh55M or this DIY approach, looks fun.