HOW TO REDUCE MACHINE COMPONENT ATTRITION?

Mark there is no need to YELL here. Turn it down, please.

While you're waiting for other to reply, search the fine SMTnet Archives to find threads like: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=34512

You'll find that the following affect the "attrition rate": * Assembly machine program * Machine calibration and maintenance * Part characteristic * Machine setup * Proximity of part to end of tape * Machine vision calibration * PCB layout * Pad factors.

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Mark, the only Panasonics I've worked with were MSHIIs and an MPAV2B and at this point I'm foggy on both, but both tracked component inspection errors quite well. You should be able to tell how many parts are rejected for thickness inspection errors (which could very well be nozzle problems or true component thickness issues, not uncommon when you change suppliers), X/Y dimensional problems, centering issues, missed picks, etc.

The vast majority of errors we experienced on the chip shooters were machine maintenance and repair issues.

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Mark,

On most chipshooters that have a few years of use on them you will find the feeders play a dramatic role in component attrition.

I don't know the panasonic software.

On Fuji you can get a breakdown of placement errors in different forms. One form is errors off on each feeder. This can lead you to feeders performing poorly which when fixed can dramatically reduce attrition.

Jerry

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Those Panasonic machines should be able to tell ya pick-up rates form the feeders and shape code errors (components it doesn't recognize). You will probably get a more pick-up errors than anything else. Most of this is due to plastic tape versus paper and/or thickness range of the part. Sometimes the part may be too tight for the tape, but it it kind of rare.

Nw for 0402's and 0603's, you will prob. have more thrown away by loading a feeder than you will running your work order. Unfortunately, the software does not account for these parts hitting the floor.

Reducing attrition for chip parts is a weird request. You should not be having hardly any fallout for a chip component, especially this small. If you do, there is something wrong. Are these "used parts with dried out old crust solder paste on them? (Yes, i have seen this!) Or do you have a setting too tight?

Now all the above assumes you have proper P.M. Clogged or dirty filters can cause weak vacuum, which leads to parts falling off the nozzle. Chipped nozzles can also do the same. But the software should be able to identify the head and/or nozzle that is causing the most defect rates.

Hope this helps you. Let us know more detail or if you found what your problem was, cause a few us bet on these posts.

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Proper care and calibration of feeders helps the most. Once repeatability of position is gone the machine's feeder offset will start to resemble the agility of a drunken sailor. That can manifest itself in vision errors or worse as placement problems.

After that religiously maintain the vacuum system including source, valves and sensors.

There's a lot of feeders out there that were originally designed for 0805's that have been pressed into service with parts as small as 0403s. If you want higher reliability you'll have to rethink feeder calibration and DOE even beyond the original specs. It doesn't take a genius to rethink calibration if you add a PC video system to a fixture. Overlay a grid and measure variation to verify or weed out feeders that need a complete overhaul.

It's too bad mfrs driven by customer demand have to overestimate MTBF and PM intervals but that's a market driven reality. Then usres as a cost cutting measure tend to further reduce the PM frequency and wonder why they have problems.

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