Issue link: https://iconnect007.uberflip.com/i/1305670
70 SMT007 MAGAZINE I NOVEMBER 2020 While the PerfecTest coupon system is not available today, the idea can still be incorpo- rated into any CAM system if an AOI system is not available to measure inner layer shifting. Conclusions For as long as there has been printed cir- cuit production, there have been coupons to test every factor. Many excellent coupons have been designed over the years—too many for me to address here. The choices now are greater than ever. Hopefully, you use one of these systems. You can buy it, rent it, or develop it yourself. The economic pressures of competition makes that an imperative. A statistical software package and training are available for free at NIST/SEMATECH [7] . But without something, you are going to find it increasingly difficult to stay in business either because of profitability or reliability. SMT007 References 1. Hong Kong Productivity Council, hkpc.org. 2. Rhodes, R.J., & Estes, T.A., "HDI Performance Valida- tion II," The Board Authority, June 2000, cat-test.info. 3. Estes, T., & Neves, B., "The Effect of Lead-Free Reflow Profiles on Through Via Reliability," D-36 Subcommittee Report, February 21, 2005, pcbquality.com. 4. Wolf, D., "Highly Accelerated Thermal Shock (HATS TM ) Reliability Testing," SMTA HEE Conference, June 24, 2003. 5. Burch, B., "Accelerated Interconnect Stress Test for Total Interconnect Solutions Using IST Technology," Feb- ruary 5, 2004, pwbcorp.com. 6. "Tech Note: Test Resolution," publication of American Testing Corporation, Redmond, Washington. 7. Holden, H., "The Need For Statistical Tools," CircuiTree Magazine, October 2002. Happy Holden has worked in printed circuit technology since 1970 with Hewlett-Packard, NanYa/Westwood, Merix, Foxconn and Gentex. He is currently a contributing technical editor with I-Connect007. Figure 7: PerfectTest was a material movement and registration coupon system; (a) the coupons were 0.2" x 1.73" and placed at the edges of production multilayer panels, (b) it worked by measuring the continuity of PTH versus the metal foil of specific layers, (c) the testing equipment included a close-up of the probe head, and (d) data from one user in production of nearly 250,000 readings for 12-layer to 26-layer multilayers [6] .