An Experimental and Numerical Investigation Into Multilayer Probe Card Layout Design

Abstract

This paper conducts experimental and numerical investigations into the microforce probing technique used to test the functionality of IC devices. The study commences by considering the case of a single tungsten needle probe and examines the relationship between the contact force and the scrub mark size on aluminum pads at various levels of overdrive and shooting angle. Subsequently, a three-dimensional computational model is developed to facilitate the design of an optimum multilayer needle card layout. The simulation results obtained for the profile and size of the scrub marks on the upper surface of the aluminum pads of an IC device are found to be in good agreement with the experimental observations. The validated model is then applied to analyze the effects of the tip length and beam length on the scrub mark profile and the stress distribution contours within the needle during a wafer level test. The results predicted by the finite-element model (FEM) for the scrub mark length under various beam lengths are used to specify a suitable design for a multilayer needle layout. Taking the case of DDR2 SDRAM of an aluminum pad of dimensions 70 m 70 m (length by width), the numerical results enable appropriate values to be assigned to the shooting angles, beam lengths, and tip lengths of the individual needles within a four-layer probe card.Index Terms-Finite-element method (FEM), microforce tests, multilayer needle card, wafer probing test.

Optimization of Multilayer Probe Card Using Strain Energy-Based Analytical Model and Multiobjective Programming Algorithm

“…The nodes and elements of the meshed model were then input to ABAQUS for analysis purposes. In performing the simulations, the Young's modulus and Poisson's ratio of the needle were specified as 290.85 GPa and 0.28, respectively [2]. Furthermore, the pad was assumed to be a rigid body [8].…”

“…In most practical applications, the contact force should not exceed 2.5 gf/mil and the scrub mark should terminate at a point no closer than 5-8 μm from the pad boundary [1]. The literature contains many numerical and experimental investigations into the relationship between the contact force and the scrub mark length in the probe testing of aluminum pads using a single tungsten needle [2]- [5]. In general, the results show that the contact force and the scrub mark length both increase with an increasing overdrive level.…”

Geometric design for ultra-long needle probe card for digital light processing wafer testing

“…Mechanical response of the aluminum pad is described by a linearly elastic-perfectly plastic constitutive model. The stressstrain relationship of the tungsten needle was obtained by tensile testing [12]. Table 2 briefly summarizes key characteristics of the mechanical behaviors of the components.…”

Experimental investigation and finite element analysis of bump wafer probing

“…Tan [11] used cantilever and membrane probe card to evaluate the reliability of the probe-before-bump process. While many studies have been done on before bump probing and AI pad probing with cantilever probe card [7][8], but few studies have reported on solder after bump probing research topic.…”