Prior to integrated circuit (IC) packaging, die performance must be verified using probe cards to screen for defective products. With the decrease in IC line width, the dimensions of the pads used for performance verification and the spacing between adjacent pads have also decreased. However, when the pad pitch is reduced to less than 30 μm, commonly used probe cards will face manufacturing problems in miniaturization. To resolve probe card manufacturing problems caused by the miniaturization of IC components, the use of an anisotropic conductive film (ACF) in probe cards was proposed in this study. Theoretical calculations and experimental testing of this probe structure were conducted to demonstrate the feasibility of this concept.
In theoretical calculations, composite material and buckling theory were utilized to evaluate the buckling behavior of the ACF. In experimental testing, photolithography and electroplating techniques were used to control the line width and spacing intervals of the micron-scale metal wires in the ACF. After the ACF was fabricated, the mechanical properties of the ACF during wafer testing were assessed. Theoretical analyses and experimental testing verified that ACFs can potentially be applied to the performance verification of IC products. In the ACF structure, multiple probes came into contact with each pad. Therefore, ACFs can potentially be applied to the performance verification of IC components with pad diameters of less than 20 μm. The results of this study directly benefit the miniaturization of ICs.