LitePlacer.com forums

Hey ...

I am just wondering ... How super difficult would it be to add a solder dispenser ?
The hardest part could be the amount of solder which will be different per pad (size).

Actually it is just an open question, ready for some debate/discussion;
I am not sure myself yet whether this is efficient really. Point is, solder mask stencils add $$ too and can easily be as expensive as the (prototyping) PCB's.

It's a little stealing perhaps, but for 200 euros this one should do the job on the hardware side without sorting out too much in advance. : http://cirqoid.com/products/dispensing-add-on
So I suppose we can just get such one from there without the surrounding machine (haha).
And oh, when we are as far as that this is going to work, add a (drilling) spindle as well. But that's for later thoughts and maybe not really feasable (multi layer).
Anyway, if it only *seems* a good idea I would be ready to invest such a dispenser and send it to you, Juha, so it can be toyed with. No real obligations to get it to work, except the attempt.

But again, maybe it is not a good idea at all and people may have all kind of con's to this idea.
Regards,
Peter

The cons that immediately come in to my mind are:

- Would this really be cost-effective? The Cirqoid add-on is 200€ itself, and likely, needs something else to work properly. Prototyping stencils are something like 15€ / A4, so you'll get quite a few with the price of the add on.

- As you noted, controlling the amount of paste might be an issue. The software could adapt to the pad sizes since it knows the part, but paste is inherently messy, the amount might vary too much anyway. A stencil gives precise control of the paste amount, which, imo, is crucial for good results.

- It would be slow. On the other hand, the machine is slow anyway, and this is about prototype builds: You'd still get your board done on the same day, even if the machine would spend couple of hours going through the pads.

- If you would spend a couple of hundred in order to never needing to pay for stencils, a cutter would be an alternative. I haven't tried it myself, but I have heard good results from Silhouette Cameo cutter for stencils. Also, your local hackerspace might have a laser cutter?

Thank you for your offer, but for now, I'll have to pass. There are a couple of Maker Faires to attend, a motor issue to sort out and the software needs support for better IC placement.

OK, I am 100% fine with that.
It is only that we pay something like 60USD and close to the same for shipping. But it can well be that this is because of the wrong (Chinese) place to do this.

Thanks for the honest anwer,
Peter

http://www.smtstencil.co.uk/
No association, not even ordered from them, just bookmarked.

JuKu wrote:http://www.smtstencil.co.uk/
No association, not even ordered from them, just bookmarked.

No Solder Dispenser needed any more !
Thanks ...

I was thinking about this. The only issue I have is that I have no clue where one would mount it.

This is a inexpensive device that uses air pressure to dispense. http://www.ebay.com/itm/Solder-Paste-Gl ... 1280179207 and looks easy enough to interface.

I own a similar liquid / solder paste dispensing system, like the one Reza linked to, and use it to apply paste by hand for one-off prototypes.

You will need a separate air compressor to use it. It works quite simplistic - it has a regulator for compressed air (mechanic) and a small venturi system which generates vacuum, two solenoid valves and an adjustable timer. Once you push the button, one valve opens and compressed air pushes the paste (or whatever liquid) from the syringe. After timer times out, pressure valve closes and the other, the vacuum valve, opens to stop liquid from dropping out.

If you mounted the syringe to the gantry, you could build an automated solder paste dispenser - probably need to override the timer to control the amount of paste dispensed depending on the pad size. Alternatively, you could keep the timer and always apply a small dot of paste, but place multiple dots on larger pads.

I think the bigger challenge is in software - you need to determine the location of the pads and their size / amount of paste. Also, you need to adjust the correct Z-level for the syringe needle to barely touch the PCB.

IMHO, the effort is not worth the gain as stencils come cheap and if you really want to build just one board, you could still apply the paste by hand.