Solder paste stencil printer for 0.4mm pin pitch. - Page 1
Forum section: electronics / general

author: wraper
author_rank: Unknown
timestamp: February 16, 2017, 02:05:20 pm
content: Can anyone suggest a solder paste stencil printer which canreliablywork down to 0.4mm pin pitch and costs below EUR 2500? Preferably with supplier in EU. If something works fine down to 0.5mm, worth mentioning too. Googled a lot, and have read several treads on the forum, but I still did not figured out. Either it is something extremely expensive like LPKF ProtoPrint S RP or those Chinese printers for around $500 which don't seem to be up for the task.

author: hcglitte
author_rank: Regular Contributor
timestamp: February 16, 2017, 10:11:35 pm
content: Hi,I am looking for a printer myself, but hopefully a bitt less expensive - and for framed stencils, since these have become a lot less expensive nowadays.Anyway, I have been a bit inspired by this setup using a wood base with wood as guides:https://hackaday.io/project/6444-vinduino-a-wine-growers-water-saving-project/log/34188-using-a-solder-paste-stencilPreviously I have used the same idea, but with unframed stencils and packing tape as the hinge.The alignment procedure was quick, and the apertures to PCB land patterns repeatability was good.The latter I assume may be variable due to how the boards are cut in batches (placed on top of each other).I received two framed stencils today, so I will try it out next week.The wood frame idea appeals to me because then you only need to make the alignment once. This requires that the PCB's are cut to precision of course.And, when you need to do the same PCB later, you can take out the wood base from your storage.One would also need a very planar wood base. The first idea that came to me is to use an IKEA shelf for each setup - which you can buy in single quantities.Another benefit is that this setup features vertical stencil separation from board - although manual.I would like to know if anyone has tried this setup before, and if it works successfully.It could be that there are other potential issues with this idea. I guess I have to try it out!HC

author: wraper
author_rank: Unknown
timestamp: February 16, 2017, 10:36:27 pm
content: Quote from: hcglitte on February 16, 2017, 10:11:35 pmWon't work for me. Right now I'm doing a similar approach but different in realization. The issue is, routing from board to board varies by about 0.2mm. Therefore, there is pad position variation which causes hell a lot of problems at such fine pin pitch. Especially considering I usually do about 20x18 cm panels, where each corner need to be perfectly aligned. Also propery lifting of the stencil after applying the paste is very important too, as this may screw all of the process.

author: hcglitte
author_rank: Regular Contributor
timestamp: February 16, 2017, 11:33:40 pm
content: Thanks for the heads up! I'm doing about the same panel size and 0.5 mm QFN pitch. With my current setup I have not had any QFN issues.But I have had issues with a LGA part (RF PA amp) which has a higher pitch of about 0.6 to 0.7 mm.I have now reduced the center thermal paste aperture (initially I used the recommended aperture size according to datasheet though).There are many via's on the thermal pad, and I have read that this may cause voiding which may cause shorts...So if this next stencil setup does not work (assuming perfect print), I guess I have to use plugged via holes.Perhaps the p&p machine places the part with too much pressure for all I know...Anyway, did you see my other post where I linked to the 500-ish USD printer from aliexpress?It looks like the quality is OK - but hard to say...

author: CM800
author_rank: Frequent Contributor
timestamp: February 17, 2017, 07:12:54 am
content: Why not build one yourself?Buy some Aluminium tooling plate (10mm+ thick)Buy some various other shaped pieces of AluminiumBuy some good hinges.Align it, clamp it, then braze it together. There are plenty of tutorials out there.Intelligent planning / design can remove any play and promise good repeatability.You don't even need milling / cutting facilities these days. You can buy metal pre-cut with 1mm tolerance. That's good enough if you play smart and only rely on the sides that are precise. (tooling plate is very flat / specified on it's plane.To be honest you could get metal sheets laser / water cut quite cheaply too via online suppliers.If you're into it, it's quite fun building these kinds of things yourself. Learning / having the skill holds good benefit in the future (doing other stuff you need DIY, home DIY, make your own furniture / tables)

author: wraper
author_rank: Unknown
timestamp: February 17, 2017, 09:41:20 am
content: Quote from: CM800 on February 17, 2017, 07:12:54 amBecause it will be a piece of crap and $500 Chinese stencil printer likely will work better. Don't forget that about 0.05 mm backlash is the absolute maximum which is acceptable. Stencil printer also needs fine position adjustments to work well. Also, I need this stencil printer to make money. If the time needed to spent to build one would be used to do things that bring the money in, it would bring much more money than such DIY printer is worth.QuoteI'm into electronics, not metalworking.

author: hcglitte
author_rank: Regular Contributor
timestamp: February 17, 2017, 04:57:16 pm
content: In case interested:I did a test now with my framed stencil. I took the PCB panel and placed it on my table.I used 1 mm thick tape around the PCB to lock it into a fixed position. (I should also have used some thin double sided adhesive tape to make the PCB stick to the table).I placed paste onto the top of the stencil frame, then aligned the frame (not at all so much trouble),took my left hand and held the frame down to the table (on the paste side) and thenI used the squeegee in multiple passes. I believe best result is achieved with one pass, but the squeegee I use don't allow for that now - will need to frame it.I used my left hand pressing the frame down towards the table (still), and my right hand on the opposite side to lift the frame up - my left hand acting as a hinge sort of.This worked surprisingly well and the paste print was perfect in my opinion. My smallest part is 0402, and QFN's.Since this was a test print, I had to clean the board for 10 minutes...Anyone done it similarly?HC

author: wraper
author_rank: Unknown
timestamp: February 17, 2017, 05:05:14 pm
content: Quote from: hcglitte on February 17, 2017, 04:57:16 pmAnd now imagine you need to do this with 50 panels with 100% success. Cleaning misapplied solder paste is huge pita and time waster, as it gets into every tiny via, in the gaps between the pad and solder mask (hard to see without microscope, though). Only solvent in ultrasonic bath gets all of it out from the board.

author: hcglitte
author_rank: Regular Contributor
timestamp: February 17, 2017, 05:26:42 pm
content: I agree, that is not an option for larger runs. But 10 panels for one day of work is OK. I will eventually buy a quality one.I would say it makes little sense having invested in a Mechatronika M10V p&p and no propper stencil printer.The one I have used until now is the SD-240 printer which does not work well for larger panels.I noticed that I had to do many wipes in many directions with some force in order to clean between solder mask and pad, yes!The VIA holes I dont care if have residue paste (although this perhaps could be an issue with the thermal pads below the QFN's with respect to voiding etc?).And yes, I will need to invest in an ultrasonic bath as well. But they get a bit pricey when they get larger which is required for 40x30 framed stencils...Any tips on a source here would be appreciated.HC

author: olkipukki
author_rank: Frequent Contributor
timestamp: February 17, 2017, 06:06:17 pm
content: @wraperHow much LPKF guys quote for ProtoPrint S? I guess in €4K-€4.5K range at least.As you might know already, Eurocircuits sells so called eC-stencil-mate printer, 0.5mm would be okay and if you will make a stencil and PCB panels designed for their eC-system (http://www.eurocircuits.com/ec-registration-system/) thats should simplified a whole process. Below 0.5mm starts a bit tricky, but worth contact them to find out more. It seems that a reflow oven sold out long time ago, so they (might) busy working on version 2 and may be on a printer as well.

author: mrpackethead
author_rank: Super Contributor
timestamp: February 17, 2017, 06:15:07 pm
content: I know its Chinese, but the Torch T1100 semi automatic printer is really very good. Of the top of my head its about USD$2800. I used one in china, at a factory and like it and have got one coming right now.On the ultrasonic cleaner, i had a stainless steel tank made by a local fabricator, bought some ultrasonic transducers and driver from alibaba.. Clean stencils are easy.If you buy somethign that is ready made, it will cost you a bomb, but hteres nothing to it.

author: wraper
author_rank: Unknown
timestamp: February 17, 2017, 08:31:45 pm
content: Quote from: olkipukki on February 17, 2017, 06:06:17 pmI don't remember really as this was quiet a while ago. But I think was something like EUR 5k with something.

author: wraper
author_rank: Unknown
timestamp: February 17, 2017, 08:41:32 pm
content: Quote from: olkipukki on February 17, 2017, 06:06:17 pmYes I know about this. But I'm hesitant about it. As this puts additional requirements on PCB and stencil, and if the holes are drilled a bit imprecise (which you may expect from cheap PCBs), you have a problem.

author: wraper
author_rank: Unknown
timestamp: February 17, 2017, 10:25:23 pm
content: Quote from: mrpackethead on February 17, 2017, 06:15:07 pmWorth considering. No weight on their website. Interesting how much it will cost to get it here. Does it have CE mark? In case customs get curious.

author: mrpackethead
author_rank: Super Contributor
timestamp: February 18, 2017, 01:00:21 am
content: Its heavy. mine is coming via seafreight.And sorry i confused the pricign.. The T1100 ( autmatic ) is $3500, the T1000 which is semi-automatic is $2600

author: rx8pilot
author_rank: Super Contributor
timestamp: February 18, 2017, 01:29:56 am
content: Quote from: mrpackethead on February 18, 2017, 01:00:21 amThose printers look pretty good for the price. Curious how difficult it is to setup and confirm alignment. They look like it may be difficult to see the stencil surface for alignment.

author: mrpackethead
author_rank: Super Contributor
timestamp: February 18, 2017, 03:24:09 am
content: I used one, in a facotry that had been there for some time, and it was not a sales demo. It was really quite easy. I was impressed enough to buy one.

author: rx8pilot
author_rank: Super Contributor
timestamp: February 18, 2017, 03:51:57 am
content: So you got the 1100 model? Does it accept a variety of frames or do you need a specific size?Kind of awesome that you were able to test drive - not an easy option me in California.Sure look forward to hearing any notes after you receive this.Sent from my horrible mobile....

author: vzoole
author_rank: Regular Contributor
timestamp: March 10, 2017, 01:58:09 pm
content: Quote from: wraper on February 17, 2017, 08:41:32 pmYou can alignment the PCB by contour or by a pin and hole.The contour tolerance is always worse than the drill tolerance so alignment by hole is a better way..We are using eurocircuits stencil printer for small batches like 100-200 and it is easily accomplish 0.4 mm pitch.

author: richardlawson1489
author_rank: Regular Contributor
timestamp: March 17, 2017, 10:02:37 am
content: Is "Manual Solder Paste Printer Pcb Smt Stencil Printer S Size 300x240mm" will work for you?