SMT at home

So I've tried making DIY smt boards after mastering the through-hole variant. I use raw pcb:s with positive UV mask, and UV-expose them with a a pcb design laserprinted on overhead film as a mask.

But I just can't get the laser printer to produce good masks for the small smd parts. The 0603 and UDFN packages, for example. I've set my printer to 1200 dpi, but still too coarse. It's an old printer though, and I wonder if I have to get a new one. Does anyone have any experience in doing smt pcb:s at home and have any tips?

I live in Sweden, and we don't have any national pcb manufacturers that do small series of boards. So it gets pretty slow and expensive to ship them from China. Also, I like doing them from scratch. Love the handiwork.

I think you might be in the same boat as myself Mixie although I have never had a board made professionally. I use Target 3001! Discover to design my circuits and boards. It's free if you don't intend to exceed 250 pads. There are several similar programs but this one is good and I am very happy with it. The reason I mention it is because you can get pcb boards made through them and when I looked they seemed good value and quick.
I have used photoresist for years but unless there is a point source UV light available I find the results can be a little disappointing unless you can produce positives photographically.
I am tempted to try using a laser printer but for one reason or another have not got round to it. for the Target software

Sounds like it, yes :). Although I use Eagle, which is also free for this kinds of projects. I thought I might learn the gold standard right away.
I built my own UV exposure box and so far I've had excellent results with it. For me, it's the laser printer that fails.

I make home PCBs when I need quick turnaround using the photographic method.
No problem to get 10 thou.
If you want a great program look at WinQcad.
It is defunct now, but I think you can still get free downloads on the net.
I think the free version is limited to a few hundred pins.


And is it smd pcbs you do? How do you manage to print the pcb design on film? What laser printer and resolution do you use?

Both SMD and PTH.


Use ground plains to save on ink.

For the clear overheads, you might be able to send the file output to a local store if you don't have a inkjet printer.
If they only have laser jet printers, print several overhead copies and place them one on top of the other.
I have sent images to our local 'Staples' store.


So inkjet is better than laser?

IMO, the ink jet printer and these overheads is far superior to a 'laser jet using laser jet overheads'.

Just make sure you use the correct clear overheads.
One side only is usually the print on side.

To protect the ink side, after drying, cover the ink side with a plain clear plastic sheet and tape in place.