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June 25, 2018

Pick Performance for SMT Placement Machines

What rate (%) is considered World Class when it comes to Pick performance for SMT placement machines. Can you also define Pick performance?

R.W.

Experts Comments

The machine specs say 99.99% for pick reliability and place reliability.  The machines can exceed that number, however.  We recently ran a demo for a lighting company where our FX-3 chip shooter picked and placed 10,000 LED's without a mispick or a misplace.
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Bob Black
President and CEO
Juki Corporation
Mr. Black was the President and Co-Founder of Zevatech in 1977 and introduced first Pick and Place System at Nepcon West 1980. Bob is now the President, CEO and Co-Founder of Juki Automation Systems. He is also a Co-Founder of the SMEMA Council of IPC. He serves as a member of SMTA and SEMI..
From my point of view it depends on your production type: mass production, prototype, high mix, low volume, etc. I always look at the equipment that fits my current business strategy and has flexibility for any future adjustments.

A lot of manufacturers came lately with very flexible solutions for pick and place process. So if you are looking, for example, at a high speed chip shooter I would recommend to check:
  • Parts per hour
  • Feeder capacity
  • Component size range
  • Component reel diameter range supported
  • Ease of feeder re-load
  • Placement accuracy (repeatability)
  • Reject rate
  • Electrical test verification
Another important detail is how the other equipment can support the speed that you will get out of your pick and place. In other words: will this world class pick and place equipment run faster than the paste deposition machine can print the boards? Is the reflow oven capable enough and do I have a profile that can support that volume?

So from my perspective the pick performance is going to be determined based upon your needs, it will always reference to the type of product that you build. Let me know if this helps and good luck!
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Georgian Simion
Engineering and Operations Management
Independent Consultant
Georgian Simion is an independent consultant with 20+ years in electronics manufacturing engineering and operations.
Contact me at georgiansimion@yahoo.com.
There a number of factors involved in pick performance, which is basically the success rate of picking a part out of a tape and reel package or tray, and successfully placing the component on the board within the placement tolerance allowed.

There are two kinds of errors that the machines record, a true pick up error, which means that the part was not able to be picked out of the tape pocket, and vision errors, which are errors that occur because the position of the part on the nozzle just before placement would not be accurate enough for acceptable assembly integrity.

This later failure can occur also if the wrong part is loaded, thus preventing the assembly from being build incorrectly.  Factors such as damaged or dirty vacuum nozzles can also contribute to poor pick and place performance.  Chip capacitors and resistors can routinely achieve sub 1000 part per million (ppm) error rates and lower.

For the typical high speed, multi nozzle systems, it is a good idea to monitor the relative performance of each nozzle, since damage and debris can negatively impact the performance.  
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Paul J. Koep
Global Product Manager
Alpha
Mr. Koep is responsible for product planning and technical marketing for the Preform Products at Alpha. He is the co-author of several patents in the areas of soldering applications focusing on reflow and alternative methods.
A world class pick-up rate on an SMT placement machine would be 99.95% or better. Current testing on the latest 03015, about half the size of the current 01005 components, is showing pick-up rates of 99.98% at a placement speed of 35,000 components per hour.

A successful pick is the part squarely on the nozzle within the set tolerance, no vacuum leak, no tombstone, no billboard, no corner hold.
Scott Wischoffer
Marketing Manager
Fuji America Corporation
Scott Wischoffer has been in the SMT industry since 1986 with experience in service, training, sales & applications, and marketing.
Reader Comment
How is Pick performance quantified? How do you hold a pick and place company to a 99% pick performance? Is this listed on a spec sheet of all pick and place companies? There are a lot of factors that come in the place with pick performance: good parts, good feeders, good and clean nozzles. Is there a generic board and parts that can be used to quantify pick performance?
Ray Whittier, Vicor Corporation, USA
Reader Comment
While a lot of performance data is claimed here, let me set you straight. It does you no good whatsoever if you can place a bazillion parts per hour with a 99.9999999999% accuracy rate, if you can't keep the machine running at least 4-6 hours non-stop during each 8-hour production shift, in a low-volume, high-mix product scenario as an example.

Losing 4 hours of "available" machine run time every single day is 2,084 hours per year that entire LINE is not running. If you figure a cost-of-doing business for an "average" SMT production line is anywhere from a minimum of perhaps $5000 per shift, (this cost includes everything a typical company might pay for, including utilities, labor, operating permits, building licenses, indirect charges, materials, etc, etc,) then you can see that even a small mom/pop business will see $2000 of lost "production per hour" per shift.

Well, $2000 times two shifts per day is $4000, times 5 days a week is $20,000, times 52 weeks, is at least $1,000,000! Therefore you need to consider just how easily or quickly any pick and place machine can be turned around between each job.

Even for companies that run the same cellphone boards all day, every day the set-up times or conversely, the machine run times are always critical. If your pick and place machine does not have the capability to notify the operator prior to the end of each feeder fill, indicate which feeders are empty and can be pulled and replaced while the machine is still running and then have the machine come back and finish picking from the replenished feeder(s), or cannot indicate when each feeder is no longer needed as the last board of a production lot is built, the time wasted waiting for the entire build to finish can be very, very costly.

So, when considering a new placer, be sure to understand exactly what has to happen during tear down of one job and set-up of the next. I have seen so many people buy a machine based on pick speed and accuracy, but realize afterwards that they just shot themselves in the foot because they need to re-teach each feeder location after the set-up is done, or they can't use cut tapes, or they can't fit enough matrix trays on, or they can't automatically update the MRP inventory using the machine management software, or they can't automatically identify only which feeders that need to come off for one job, and which ones can stay on for the next, or......well, you get my message.
Odin Stadheim, Rennesbo Automatikkers AS
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