It's more expensive but the last time I did research this, I found this one:
http://be.eurocircuits.com/shop/offtheshelf/product.aspx?ad=13777&ano=ec-stencil-mate&an=ec-stencil-mateAs you already know from our off-site conversation - I really like having the pivot off axis as I've found the separation of frame and PCB after the print much better that way.
EDIT: I saw the one you linked also has the pivot slightly off axis.
EDIT2: Just realized you're asking for a framed stencil printer... That eurocircuits one does not fit the bill then...
As you already know from our off-site conversation - I really like having the pivot off axis as I've found the separation of frame and PCB after the print much better that way.
EDIT: I saw the one you linked also has the pivot slightly off axis.
Could you please elaborate on this? What do you mean by "off-axis"? Being higher than the stencil plane?
Could you please elaborate on this? What do you mean by "off-axis"? Being higher than the stencil plane?
Yes, higher than the stencil plane.
I've found that if the stencil lifts off at one side before the other it tends to blur out the print that gets separation last. If the pivot is sufficiently off axis then you get separation on the entire PCB when you lift the frame away.
I can add that my test conditions were poor, and I've maybe reached the wrong conclusion - but the results I got were consistently worse with on axis pivot. The two jigs were both self made, the solder paste was a bit too hot/liquid and I'm not very experienced with pastes. Still, I'd say the difference for me was big enough to make it a requirement if I out grow my current DIY solutions.
Yes, higher than the stencil plane.
I've found that if the stencil lifts off at one side before the other it tends to blur out the print that gets separation last. If the pivot is sufficiently off axis then you get separation on the entire PCB when you lift the frame away.
Sorry, this does not make sense. The side that is closer to the pivot axis always lifts up slower, no matter what's the vertical position of the axis is.
But far more importantly, when your axis is higher, the stencil MOVES LATERALLY (away from the pivot) at the separation moment, and any small pitch apertures that run parallel to the pivot axis and sufficiently close to it don't separate from the paste at all.
So for the best result you need to have pivot point exactly on the same level with stencil plane.
I was just as surprised as you.
Remember though, the axis is quite a distance away from the print. It will only move 'forward' as much as the radius allows, which for my jig and those I've seen online seems to be long enough so you're really only left with the fact it's going up. Maybe the fault in my tests were that the radius was too short in my on-axis jig.
I guess a strictly vertical movement would be the best way to go though? Those printers seem overly expensive to me though, saw a few at Electronica.
what was the smallest part that you printed? I guess you can get away with just any setup if you only do 0603 and SO-8 and bigger
Strictly vertical movement would obviously be the best.
It was a board with several 0402, a couple of QFNs.
This one:
which is incidentally designed by the OP!
Do you have a stencil printer ar__systems?
I'd be curious to see what people do.
I have a simple printer similar to the one in the link. I suppose you are right, if your print area is far from the pivot, you are reducing effect of lateral movement and get closer to vertical separation.
I did not notice the effect until I had to print longer boards where some parts were relatively close to the frame.
Anyone here has a suggestion for a good China stencil printer that can do fine pitch?
What is fine print for you?
Any printer should be able to do it as long as it succeeds on its job, which has more to do with registration than anything else.
After that is up to you, your apertures, your squeegee and your paste.
What is fine print for you?
Any printer should be able to do it as long as it succeeds on its job, which has more to do with registration than anything else.
After that is up to you, your apertures, your squeegee and your paste.
Nothing too advanced to me, just some TQFP.
Problem is that my current one is simply too shaky due to weak structure so it's easy to misprint. With very minor pressure I can move the screen 3-4mm left/right.
Mhm, but I could set a steel in the base where I place the PCB pin, and drill a matching hole in the alu frame. Then the stencil has no left/right movement.
PS: your link is something that appears only in my dreams ;-)
I bought one of these:
http://www.ebay.com.au/itm/High-Precision-Manual-Pcb-Screen-Press-Precise-Stencil-Solder-Printing-Machine-Z-/282465406352?hash=item41c4400d90As I do mostly double sided smd, I wanted something that held the board up off the bed.
I think the build quality is quite good, though it did need a bit of tweaking and it would be nice if there was less backlash in the alignment knobs, but once it is set and locked, it seems quite repeatable, though I have not used it much as yet.
If you did get one, ask them for a second circuit board mounting kit, as it is handy to have the extra pcb supports.
And then get your panels and stencils with mounting/alignment holes on the boarders for really easy set up.
I saw this one online:
https://detail.1688.com/offer/542217296586.html (about US$250) but they have no sample that I can check. They are not too far away for me ;-) And they have some delivery time.
I will modify mine now to control the left/right movement of the alu frame. In the medium term I would probably just build one. Those models IMHO have design flaws, they are not designed for PCB use, hence you can adjust the height - I don't need that! It adds too many parts that decrease stability.
I would align the U-part were you fix the frame with the PCB table - and then simply put a piece of laminate under the frame to compensate the PCB thickness.
Little update: I bout the one that I posted 2 messages above. Not from that seller though, they had no stock and I really wanted to see one be buying it. So I found the same from another seller that had one in stock and went to Shajing, near Shenzhen.
Long story short, I brought my stencil and a PCB to fix it, I wanted to try how stable it is - and it's good enough. Very little left/right movement.
Can recommend it for a manual hand model.
Can you give me the link of the seller where you got it from.
I'm in need of one now I have my own pick and place. I use a fixture now like stencil8 that i got custom
milled in Shenzhen. But this seems so more convenient to work with.
Can you give me the link of the seller where you got it from.
Who? Me?
I bought mine here:
https://detail.1688.com/offer/1229805838.htmlIt's more or less walking distance from the Shajing Subway station. However, that place wasn't really an office and in a total mess. As most 1688 'companies' it's just a single person (lady in this case) venture. Anyway, she had one printer only - and that's mine now. No idea if she can get another one. And btw, no English.
In case you like or need to search more the terms are: *** (sorry, had to remove, forum can't handle Chinese, see pix)
Anyway, printer design is OK. Quite stable. If she can't help. look for a similar design.
In case you prefer those cheap RMB 100 ones - I have one of those and let it go for RMB 50 if you pick it up in Hong Kong (NT) ;-)
Any suggestions for an automatic or semi automatic printer? There are several good Chinese pnp machines below 10k USD... are there any good printer also?
Torch make some good machines. I'm quite impressed with mine. It was about $2500
can you tell me which one do you have?
I got mine in, quite hefty and sturdy, Once tighten up (some bolts were not tight) there seems to be very little play.
will do a test tomorrow when my stencils and boards come in. This one was around 1880 RMB.
I only had a quick look at it. Not fully sure how you actually hold the pcb with the provided tools / standoffs
Hopefully my stencil pains are gone!
keep it away from the glass table