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April 2016 • SMT Magazine 53 half a dozen changeovers per line per day. Cli- ent benefit is obvious in terms of better qual- ity products that carry its name and reputation. However, such an expensive practice contra- dicts the trend towards lower cost. The company takes a holistic view to run- ning their factories efficiently. Verifying that the reflow oven is ready for an in-spec reflow reduces cost associated with rework and scrap. The company recently was reminded of the cost of poor solderability when it acquired another EMS company. Before implementing the best manufacturing practices at this facility, $7,000 worth of assemblies were scrapped due to incor- rect reflow. All this profiling downtime is costly, and part of Lean manufacturing is to seek out op- portunities for improvements. The company wanted to significantly improve the time it takes to dial in an oven for a new assembly, as well as to speed up profiling after oven change- over. The first step was to acquire prediction software that would identify the most appro- priate oven recipe for a new assembly. With literally billions of possible oven recipes, the old-fashioned, manual trial and error approach was wasting time. Also, the manual tweaking of the oven recipe depends on operator skill, and it tends to lead to oven recipes that are not op- timized for quick oven changeover. While the new oven setup software eliminated the trial and error approach, it still relied on running manual profiles. The company's second step was to invest in a KIC automatic profiling system (Figure 2). Once the automatic system has been pro- grammed, oven changeover is a simple matter of loading the product file, and the automatic system will notify the operator the instant the reflow oven is ready to run the next assembly in spec. Not a moment of unnecessary downtime is sustained. The 2-6 manual profile runs per oven per day for existing assemblies, along with the associated production downtime, are now a thing of the past. Mike Siemens estimates that with seven lines, their factory now saves a total of five hours and 15 minutes downtime per day, which represents a daily saving of $1,000. The Figure 2: An automatic profiling system, which increases production line utilization, saving both time and money. bEnEfiTs of imProvinG rEfloW and scrEEn PrinTinG ProcEssEs