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64 PCB007 MAGAZINE I AUGUST 2019 Tensile Strength and Elongation Two of the most important physical prop- erties to PCB manufacturing are the tensile strength and % elongation of the plated cop- per conductors because these properties are in- dicative of the ability for the copper metal to withstand the thermal stresses incurred during assembly and end-use. The physical properties are a result of the combined influence of the additives, suppressor, grain refin- er, and leveler. These properties also depend on the plating rate or current density, temperature at which the plating is done, and the crystal morphology. For instance, densely packed equiaxial depos- its will have better physical prop- erties than a columnar deposit. Physical properties were mea- sured according to the IPC TM- 650, 2.4.18.1 test method. Sample strips were extracted and baked in an oven at 125°C for four to six hours. An industry mechanical test instrument was used to test the strips. The measurements from this instrument were used to calculate tensile strength and elongation %. Figure 8 shows the results at two different bath ages: a fresh bath and a bath aged around 100 Ah/L. According to the results, the properties did not change much with the bath age and passed the IPC Class III requirements. Figure 7: X-hole filling capability of Process I. Figure 8: Physical properties, tensile strength, and elongation of Process I fresh and aged baths.