Issue link: https://iconnect007.uberflip.com/i/1511625
44 PCB007 MAGAZINE I NOVEMBER 2023 separation, connection crack, or material delamination in a specific region within one or multiple areas. Cycling contin- ues until the specific rejection criterion is achieved or the required numbers of cycles are passed. IBM CITC/PerfecTest®/HP PTS Coupons Plated through-hole reliability testing at IBM uses their current induced ther- mal cycle (CITC) PCB coupon. Cov- ered as IPC-TM-650 2.6.26 Method B, this small, single net coupon of 100 vias is only 1.75" x 0.3" and designed by IBM to be used many times on a panel and eas- ily adapted to in-line process monitoring. e test uses current to heat the coupon at 3 degrees per second to 245°C for a dwell time of 40 seconds and repeats the cycle for 200-700 cycles per day. e temper- ature coefficient of resistance (TCR) is measured continuously and used to determine the coupon's temperature. A 4-wire resistance bridge monitors the via daisy chain. e coupon is shown in Figure 7. Figure 7 (left) : a) PerfecTest is a material move- ment and registration coupon system. The cou- pons are 0.2" x 1.73" and placed at the edges of production multilayer panels; b) How PerfecTest works; c) Testing equipment probe head 7 . The seven coupons (PTS) designed by HP: a) Outer layer registration in 0.00025" increments; b) Inner layer registration and shifting in 0.00025" increments including 0.1 mil X-ray vernier; c) Trace/trace/pad open and short circuit on mul- tiple layers; d) Plated through-hole continuity patterns including I/L connections at various angles to the PTH; e) Artwork defects analysis in 0.00025" increments; f) Etch factor analysis in 0.00025" increments. A) HP's PTS arrange- ment with a continuity tester; B) Coupon test fix- ture for individual coupons; C) Milliohm mea- surement using a 1-amp power supply and dig- ital panel meter in a Kelvin 4-wire test config- uration. Gerber files of the seven coupons are available from the author upon request. s