Metal Finishing Guide Book


Issue link:

Contents of this Issue


Page 286 of 903

ZCT 0.34 sec 1.91 mN 0.36 sec 1.49 mN Pressure cooker 8 h 0.81 sec 0.71 mN As plated 0.33 sec 2.07 mN Pressure cooker 4 h 0.35 sec 1.54 mN Pressure cooker 8 h Betatec As plated Pressure cooker 4 h Reference Fmax 0.80 sec 0.56 mN Table 3: Results Demonstrating no Loss to Solderability After Post-Dip Treatment Steam-aging: The ���pressure cooker test��� is used to promote corrosion, diffusion, and deposit cracking. This test was conducted for a duration of 8 hours, after which contact resistance measurements were carried out. The pressure cooker test parameters included: ��� high temperature ��� high humidity ��� high pressure 105 ��C 100% RH 1.192 atm Results inferred no increase in contact resistance after 8 hours of exposure. Figure 7 depicts little change in contact resistance values for Betatec 1 and 2 test samples, before and after the pressure cooker test, using the very low tracking force of 5cN. SOLDERABILITY STUDY This study was carried out to confirm that Betatec post-dip would not effect solderability properties. The gold thickness was reduced to 0.1 ��m for these solderability tests. The lead-free alloy SAC (SnAgCu) was used as solder with the following conditions: Solder SnAgCu Temperature 245��C Density 7.5 mg/mm3 Immersion time 10 s Sensitivity 2.5 Submergence 3 mm Velocity 21 mm/s All tests were conducted in accordance with the IEC-68-2-69 standard using a Litton Kester 950 E3.5 flux. Both zero crossing time (ZCT) and wetting force (Fmax) were used to assess solderability, highlighted in Table 3. 279

Articles in this issue

view archives of Metal Finishing Guide Book - 2012-2013