Issue link: https://iconnect007.uberflip.com/i/579391
24 SMT Magazine • October 2015 sometimes vary on the fly, speeds up assem- bly. SMAC has a new on-board laser option that allows this. Multi Z-axis machines can speed up output while actually running an individual axis slow- er, which helps reduce impact. Flexible circuit substrates are quite an interesting trend. Las Marias: what about equipment downtime? how does that contribute to cycle times, and should assemblers address that? Neff: Machine downtime comes from several causes. Failure of devices on the machine is one. That is normally an unplanned event and as such, is not good. That is more an expect- ed output question as opposed to cycle time. In this case, components' expected lifetimes must be at least equal to the expected life of the machine. Around three times the life is better. So instead of using components with known short life times, like ball screw drives or high current devices like moving magnet linear mo- tors, use long life products. Tied in with this is preventive mainte- nance (PM). Again, find the reasons then re- duce their impact. For example, put a hole through the pick and place rotary motor and pull vacuum through it. It gets the dust out of the system. Keep improving and reduce the need for PM. Another downtime comes from change- over. This can be for parts, such as changeover of tips, for example. This has been addressed pretty well in current machines. Las Marias: Can you give some examples as to how manufacturers can address the impact of cy- cle time on costs? Neff: Manufacturers should first review their own products and simplify wherever possible. Reduce number of parts, limit the number of tool changes. Periodic review of new technol- ogy is also a good thing to do. Doing this sys- tematically, with basic corporate goals such as yearly cost down % and sales/capacity %, get results. At SMAC, we do this through the oper- ating budget plan. Las Marias: Finally, what about quality? how do you ensure that quality remains the same through- out the assembly line as you strive to reduce cycle times? Neff: Quality should always improve, not re- main static. A good way to approach this is first to determine what is critical. Then build in 100% check of these items. As failures occur, immediately determine what caused these, and correct these issues so that they do not occur again. Also, tighten specifications and improve critical processes for those critical elements. Mechatronic devices that perform work and verify the success of the work are an example of how to do this. For instance, a major auto maker tests switches using SMAC devices; they used to use air cylinders that simply confirmed the switch worked. The MCA does that but also shows where in the stroke the switch turned on and off, and what force was needed. It tells the customer about the quality of the switch. When parts are assembled, the MCA can do the work and also tell if the assembly was done correctly by feeding back information on end position of the assembly, how much force was required to make the assembly, etc. Las Marias: thank you very much for your time, edward. Neff: Thank you, Stephen. SMt chooSInG the rIGht coMPonent to reduce cycLe tIMeS FeATure inTerview " Periodic review of new technology is also a good thing to do. doing this systematically, with basic corporate goals such as yearly cost down % and sales/capacity %, get results. "