Issue link: https://iconnect007.uberflip.com/i/393082
October 2014 • The PCB Magazine 45 values for the boards. Cross-sections of the TV1 and TV2 are given in Figure 11 and Figure 12, respectively. Table 6 shows the mean value for a random sample of 15 TVs with the thickness measured manually with micrometer gauge. Reflow performance The results of the reflow testing are summa- rized in Table 7. The results of the components show that the HDI/FV board performed signifi- THIN PCBS FOR SMARTPHONES continues table 5: Parameter set applied for hast testing. figure 7: Via-to-via and via-to-plane test structures of hast test coupon. figure 8: Comb structure, front layer of applied hast test coupon. figure 9: thinboard hast test coupon. table 6: thickness values of built test boards. cantly better than the two ALIVH build-ups. While at the TV2 and TV3 most of the delami- nation failures occurred between the third and fourth reflow cycle, all TV1 samples survived a number of 15 reflow runs. An example for a typ- ical failure that was observed at TV2 and TV3 is given in Figure 13. However, it has to be pointed out that the big difference observed cannot be directly relat- ed to the influence of the manufacturing pro-