performance improvement

Most SMT lines are comprised of several pieces of equipment. Each piece of equipment, the components, the plant environment, and the people running the line can have / cause variations in their operation that each can affect product quality. Consider focusing on the element of your production process that is the major source of variation.

Understand, we are a very task oriented group. In order for us to help you further, in any meaningful way, we need information about: * Defects * Machine and machine set-up * Components, board fabrication, etc * Etc

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DaveF's request for more data of course is needed to be specific, but here are a few ideas and places to start. If the SMT line is causing the defects you need to identify where on the line the problem is being caused. What we see regularly is mishandling of boards coming off the line, ie. stuffed in totes, piled in bins, put in the old style flat racks that store boards on edge on an angle. The best way is to use the tray cart method that allows for a flat surface for the boards to lay on. This eliminates flexing and microfractures in addition to virtually eliminating ESD problems as the operators are handling the tray not the board except of course when they first take the board off the line. If misplaced components are the problem are the feeders in good condition, how are you storing them, they need to be stored properly in proper feeder racks to propect your investment and ensure they work correctly, consistently. If feeder changeover time is more than 20 minutes, you need to pre-stage feeders, if feeder exhaust during a run is taking more that 20 seconds you need to be pre-staging the known needed backup feeders at the machine. These two methods will typically gain you 1-2 hours per 8 hour shift of additional uptime. For more information on handling go to http://www.blissindustries.com and click on Bliss University.

I hope that helps

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The first question is, is this a high mix, low volume environment or vice versa? If it's the former then Kens solution is something you might want to look into. Depending on your feeder set up you might check to see if your operators have been trained to properly to use the CP6 Device table modes for change overs, if your budget allows you should get an extra set of MFU's for your IP3, that will also speed up change overs. You might also want to look at the line balance and program optimization of your placing programs. If you're low mix, high volume then start looking for stoppages and their causes. you can use the production reports or line monitor (depending on which programming software you are using on the Fuji's) these are pretty good tools to see whats happening on the floor. Assuming you didn't buy used equipment that is beat half to death, then the equipment shouldn't be a major problem. Fuji's are built like tanks and tend to be very reliable. So my guess at this point is that you may have some operational procedures that need to be streamlined. If you need a little more help with your Fuji's drop me a note offline and I'll see if I can help, I have a fairly strong background with their equipment.

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If you don't already have one, the best investment you can make in your case is a good thermometer/humidity meter. They are not at all expensive. Then record the temperature and RH about 4 times a shift. After a few weeks (maybe sooner) you can see if there is a correlation with your PPM rate. There is debate about whether you need a reflow profile for each board or how many different ones you do need. If all your boards have the same PPM defect rate variety, then that is probably not your problem, if on the other hand you sort boards largest thermal mass to smallest and one or both extremes have the highest PPM defect rates, then there is your culprit. Another thing to consider is the actual measureing of your PPM defect rate. Last I heard people are 60-70% repeatable and AOI is 80-90% repeatable. You might sort your boards by colour of shininess of finish, and see if you can find any correlation. AOI might be finding more defects with some finishs more than others. Suspect all data. SMT magazine a few months ago had an article where they checked 1,000,000,000 joints. They found a reject rate of about 1,100 PPM. Everyone thinks they do better but the data didn't show it. Anyone with always better than 250PPM is missing a lot of defects, or is doing much better than almost everyone else.

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