Thinking of automated paste printer, worth it for lower production numbers? - Page 1
Forum section: electronics / general

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: November 04, 2021, 07:39:32 pm
content: Typically do 60-80 PCB sides per day, and we make PCBs in batches, and there can be weeks in-between runs. Right now we have a manual stencil machine. It works, but I've been thinking of upgrading.Is the juice worth the squeeze for low count production?

author: Reckless
author_rank: Frequent Contributor
timestamp: November 05, 2021, 04:59:21 am
content: 60-80 pcs is alot per day. If you are doing 0402 or smaller then it is worth it. The main issues with pcb production are 80% in solder paste and applying it evenly. The most important thing to invest in after pick place machine is a proper stencil printer.I have a DEK Horizon 03i (windows xp way better than 7/8/10) for sale and an MPM SP-2000 (semi automatic) if interested. Both apply even pressure on squeegee to apply proper paste evenly across pcb.

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: November 05, 2021, 08:45:12 pm
content: Smallest is SOT23/1206.I don't have any issues with paste application, just looking to reduce labor.

author: SMTech
author_rank: Frequent Contributor
timestamp: November 06, 2021, 11:04:20 am
content: if you are really not going below 1206/sot23 where you can basically get away with shockingly bad printing to no visible adverse affect I suspect its not worth it. If you went inline you'd lose the need to paste and rack boards or continuously walk between the printer and the placement. You should be able to get an older printer pretty cheap but while they are built like tanks there's still going to be the odd solenoid, custom card or decrepid PC inside that at some point will cost you that little bit of time you saved. Of course how long you can keep making things in the 1206 world is another question, at some point something may force you towards the now ubiquitous 0.5m pitch QFN and friends and then the story changes - still doable, much less fun or forgiving.

author: EE-digger
author_rank: Frequent Contributor
timestamp: November 10, 2021, 01:23:32 am
content: I recently worked for several years at a small company producing those quantities per day with all work done by printing the paste. We had mostly 0402 but lots of 0201 mixed in and many modern, fine pitch packages. Panels full of densely packed, round quarter sized boards up to around 2"x3" in similar densities.While being at the receiving end (engineering), not the production end, I did get a good look at the process. It seems to me that the only limitation of the printing for the sizes I mentioned were the pastes available. It seemed to me like (for our machine, mfgr I forget) there was really only likeoneavailable.I did not observe any hair pulling or people grouping around the printer ... it just worked

author: jmelson
author_rank: Super Contributor
timestamp: November 10, 2021, 02:51:20 am
content: 60-80 sides a day might be in repetitive stress injury territory. I don't have a problem doing 20 sides a day on moderate sized boards 150 x 200 mm or so, by hand. I do lots of 0805 and 0603 plus SOIC SSOP and TSSOP, TQFP down to 0.5mm lead pitch, with very good results with a home-made manual printer.Jon

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 10, 2021, 03:13:26 am
content: What about a semi-automatic printer?http://en.kayosmt.com/index.php/Show/index/cid/345/id/280.html(Kayo because I've had good experiences with them for other machines, but plenty of manufacturers do them)

author: SMTech
author_rank: Frequent Contributor
timestamp: November 10, 2021, 03:49:24 pm
content: Quote from: jmelson on November 10, 2021, 02:51:20 amYeah I do that kinda volume with a clamshell, depending on the weight of your frame, stencil clamping method, gas rams etc, it can get a touch tiring. As you describe, good results are possible but you do start having to be very careful and even aligning things on a through aperture method at the 0.5mm end of the scale starts getting to be a bit of a strain, more so if you have gone HASL rather than ENIG (the gold contrast helps).

author: SMTech
author_rank: Frequent Contributor
timestamp: November 10, 2021, 04:04:11 pm
content: Quote from: Mangozac on November 10, 2021, 03:13:26 amMy issue with semi-auto, in general and with mine is while it can do repeatable pressure & angle and programmable squeegee speed, there is quiet an extensive set of manual tweaks to get the stencil level with your board. In addition; mine in particular relies on the external dimensions of your PCB being reliably consistent as that is how the board is held, of course they are not and once you get to 0.5mm pitch or below, that matters. All board fixture methods have their own advantages and disadvantages - holes that may or may not exist, a required min board thickness, no allowance for double sided boards etc. To be honest there's only one kind of semi auto I would find OK and that's one with cameras that shows you the alignment every time it raises the print table to the stencil and gives you a go/no go before it prints. They do exist, the PBT FA23/aka Essemtec SP150 or SP200 work like this but they cost dangerously close to as much money as some keenly priced automatic models that add things like full alignment, inspection and underwipe cleaning routines.

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 10, 2021, 09:28:40 pm
content: Quote from: SMTech on November 10, 2021, 04:04:11 pmI run a secondhand fully automatic (with stencil clean) printer, but from what I've seen and heard your comments are all very valid. However that doesn't seem to make the "dumb" semi-automatic models any less popular around the place when people are doing small-ish volumes.