Issue link: https://iconnect007.uberflip.com/i/845602
80 The PCB Magazine • July 2017 failure rate after two assembly thermal excur- sions. This was attributed to microetch chemi- cal type, and size of the micro-via. The second study was on plating separation, which also had high failure rates after two assembly reflow cy- cles. The solutions to this issue were to replace button plating with pattern plate, and to use a thicker wrap plate per IPC Class 3. William concluded by reviewing methods for testing to eliminate failure mode: • 5X reflow simulation • Interconnect stress testing (IST) • New thermal cycle method—CITC • -100°C vacuum environment • Extra DPA Inspection: Is it Necessary? I batted cleanup for the event, and received some feedback the day before from Tony, a qual- ity engineer colleague with one of my clients. After reading the first paragraph of the white paper I sent out as a teaser to the event, Tony told me: "Steve, you are wrong. You can never get rid of all inspection in our business; it just is not possible." I said: "You're right, Tony, but when I send you the entire paper you will see that I am talking about eliminating the profit- sucking practice of using inspection as a Band- Aid to quality problems instead of fixing the process." I discussed the point that the customer is paying for our inefficient processes through scrap, rework and returns, and that this knee- jerk reaction has a triple impact on profits: 1. Inspection by definition is a non- value-add reactive process 2. It doesn't address the root cause of the issue and assures it will resurface at some point 3. Inspection is not effective The solution is to employ the appropri- ate best-practice tools in your operation, and a number of lean methodologies, tools and tech- REVIEW OF THE 2017 IPC RELIABILITY FORUM Figure 10: Yours truly presenting.