Issue link: https://iconnect007.uberflip.com/i/1183414
102 DESIGN007 MAGAZINE I NOVEMBER 2019 ly. In addition, the conductive adhesive bond on one side had partly delaminated (Figure 8). As stated before, component mounting to 3D- curves with a small radius is against our de- sign guidelines. Extended Reliability Testing Results Testing until failure is useful for better un- derstanding structural electronics reliability. That is why we tested one of TactoTek demon- strator products for 3,000 cycles in the change of temperature test. The demonstrator product, shown in Figure 9, contains 20 pieces of Type2- LEDs. Figure 10 shows a summary of the tests and sample sizes. Two Type2-LEDs failed during 3,000 cycles. Failures occurred at 702 and at 2,988 cycles. When we fit this data into a Weibull distribu- tion, we predict a 50% failure point at over 10,000 cycles (Figure 11). Such a high value demonstrates the reliability of the technology. However, the number of tested components was small in the extended reliability testing. Thus, we have subjected more certification platforms to extended reliability testing. Figure 8: Cross-section shows a slight bending of the component base and partial delamination of conductive adhesive. Figure 9: Photo of a demonstrator product that was subjected to extended reliability testing. Figure 10: Summary of the test and sample sizes in extended reliability testing. Figure 11: Extended reliability testing failures in Weibull distribution.