Addressing Off-Centered Ball through Solder Paste Material Evaluation

Stencil printing using solder paste material is one of the challenging processes in semiconductor assembly manufacturing. During evaluation of a semiconductor device, off-centered ball issue was encountered. The study aimed to mitigate the off-centered ball issue at stencil printing process by exploring the effect of different solder paste materials. Both solder paste materials were cured using the same reflow condition. However, solder paste material 1 (S1) resulted to cold solder joints while material 2 (S2) showed cured solder paste characteristic. With S2 material used in stencil printing, the off-centered ball occurrence was eventually eliminated. For future works, the solder paste material and configuration could be used for devices with similar requirement.