In-Line Stencil Printers vs. Semi-Auto

Armin, I installed a second hand Dek Ela in-line in November. Prior to that we had been running 2 x SMTech (Quad ) Vmp100s, an MPM SP-2000 and an MPM SP-20. All semi-autos. I believe the Vmp100s to be a great machine and have recommended them to all and sundry. We installed the in-line on a line that had been running one of our main products since its inception. This product takes up about half our months production for that line. For the infomaniacs there are 1984 pads per pcb with a mix of 0603, SOP, QFP, Electros etc down to 0.020". Not earth shattering but busy. We increased our throughput from about 170 per day to about 200-205 a day. We weren't looking for this - it was a bonus. The operator just didn't have to spend as much time at the printer, he could do OTHER things. So called soldering faults fell from 5.6% to 5.0% as the cause of total faults. You can always claim that as a 12% reduction in faults if you want to. Nuff of the figures. Maz, the guy who runs this line and always has, by himself, is a conscientious, interested worker. If he put his mind to I'm sure he'd give you a good print with a butter bin lid and a stencil taped to a work bench. That's because he cares. He loves the inline because it makes his day easier -that's what is important to me. You put a crappy, unhappy, disinterested, operator on the best machine in the world you will still get - crap. He just has less opportunity to produce more complex crap (albiet in lesser numbers so I don't know how that equation levels up). Believe me, the opportunity will be found to outwit the magic machines' smarts, and it will be taken. Cost of the in-line was $80,000 compared to $60,000 new for the semi. Cost of the in-line new would be around $260,000. That's $Strayan. $260,000 might be out of our range but $80,000 for a near new machine was good. Right machine, right price, right time. Call me lucky from now on. Darby

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Armin, The obvious disadvantages for an in-line printer is initial cost and flexibility for smaller shops that depnd on high mix, low volume batch builds from their printer to support multiple projects at the same time. The advantage is quality and speed. Most Semi's require manual positioning, by means of vision tools or operator's eyes. This is more prone to error and takes longer to insure the same quality a fully auto will provide. Semi's also require post print handling, the more a board is handled from start to finish the more errors you will have. The biggest advantage is labor cost. In-line, fully automatic printers, simply does not require the same amount of operator time that a semi does. This means time better spent working on something else. With the lowering cost of new equipment and the endless supply of used equipment you should be able to find a nice printer to do the job... Go ahead and buy one with all the bells and whistles. If nothing else it will look PRETTY! That's just my opinion, I could be wrong!

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Armin,

another argument ist that the range of available options /features is totally different. E.g. automatic stencil wipers, aircondition or post print inspection systems are only avilable in auto�s. These options are also important to stabilize your process, which I think is the biggest fortune between semi�s and autos.

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Hello Armin,

If you are putting a matrix together to determine the best equipment set to use then a good path would be to start with your product and production expectations. Is this to be utilized strictly for typical SMT products?

Are there any specialized handling concerns that you will have to address with your product? ie large board, odd shaping, ultra thin products, auer boat requirements, etc.

What volumes are you looking to produce?

By having your product reviewed by your potential suppliers you can then burden them with justifying the proper system configuration, some ROI data, and then compare the data. A blanket matrix just may not give you the best data to meet your specific needs. Once you dial in your configurations you can then start looking for the best price to match.

To be honest, I represent Speeline-MPM and would be happy to have an applications engineer review your production requirements with you.

You can find more information at http://www.speedlinetechnologies.com

Please feel free to contact me if you have any questions or concerns. Sean D. 480-829-8170 ext. 14

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Hi Armin

Printing equipment can be divided into two main groups; In-line and off-line. For "small" production sites an off-line screen printer should be adequate but for high out-put placement lines, where the product cycle-time is short, an in-line system can be necessary. Before investing in an in-line machine there are several things to consider. Firstly, the out-coming print quality. Since approximately 70% of all faults found on SMD PCBs come from the solder printing process, it is important that all process parameters are known and under control. Secondly, inspection of the solder paste print is necessary. Especially if printing fine pitch. This could be done either by operator, vision or laser inspection systems.

The above is a paragraph of my technical paper "Solder paste printing" to be found on the SMT in FOCUS web-site. More info on http://www.SMTinFOCUS.com/processguide_printing.html

Regards Brian Sloth Bentzen

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