DESIGN OPTIMIZATION OF VERTICAL NEEDLE GEOMETRY FOR BUMP WAFER-LEVEL PROBING

Abstract

The purpose of this paper is mainly to develop a method to use the Taguchi method with the L18 (21 × 37) orthogonal array to obtain an optimal geometrical design of the vertical probing needle and base on various criteria to minimize the stress on the probing needle during wafer-level probing test. Furthermore, importance of the factors on the probing mark area ratio was also ranked. The results shows that as probe length, offset, and lower die gap increase, stress on the probing decrease. On the contrary, vertical probe bends decrease, stress on the probe increase. Furthermore, the body of vertical probe with rectangle cross-section is better than square and circular sharp.