Assessment of solder pad cratering strength using cold pin pull test method with pre-fabricated pin arrays

Hot pin pull test is frequently used for the pad crater evaluation. Although it carries several merits, it still has certain drawbacks such as time consuming and causing potential thermal impact on the PCB during the pin attachment process. In this paper, an innovative cold pin pull test method with pre-fabricated pin arrays is introduced. A set of fixture is designed and manufactured in advance. An array of pins can be attached to the test board at one time. With this fixture, instead of attaching the pin one by one, the test panel with pin arrays can be prepared after only two times of reflow without severe thermal impact. Compared with the conventional cold ball pull tests, this newly developed method cannot only equally exhibit the pad crater characteristics of the PCB, but also reduces the scattering in testing results. These conclusions are well proven by the experimental data generated in the present study.