Issue link: https://iconnect007.uberflip.com/i/1288481
122 PCB007 MAGAZINE I SEPTEMBER 2020 Figure 19: Failure by net. Figure 18: Resistance during the reflow of Net1 (notice that all coupons pass the first cycle). Here is a coupon structure (Figure 19). The customer had two coupons per panel. He used a laser beam on only layer-one to layer-two on one coupon. Then, he had a buried two-to-sev- en by itself, and he wanted to do seven-to-eight microvias on the second coupon's second nets. Here are the results on the next page. These all failed because of microvia failure. We had to push the aspect ratio of the microvia. There- fore, I looked at it and found out we failed. We talked to the CAM department and told them to make the following changes. We made the dielectric one mil thicker and corrected the laser via back to six mils, as seen