Fabrication of a guide block for measuring a device with fine pitch area-arrayed solder bumps

Abstract

This paper describes the design and fabrication of a guide block and micro probes, which were used for a vertical probe card to test a chip with area-arrayed solder bumps. The size of the fabricated guide block was 10 mm 9 6 mm. The guide block consisted of 172 holes to insert micro probes, 2 guide holes for exact alignment, and 4 holes for bolting between the guide block and the housing of a PCB. Pitch and size of the inserting holes were 80 lm, and 90 lm 9 30 lm, respectively. A silicon on insulator wafer was used as the substrate of the guide block to reduce micro probes insertion error. The micro probes were made of nickel-cobalt (Ni-Co) alloy using an electroplating method. The length and thickness of the micro probes were 910 and 20 lm, respectively. A vertical probe card assembled with the fabricated guide block and micro probes showed good x-y alignment and planarity errors within ±4 and ±3 lm, respectively. In addition, average leakage current and contact resistance were approximately 0.35 nA and 0.378 ohm, respectively. The proposed guide block and micro probes can be applied to a vertical probe card to test a chip with area-arrayed solder bumps.

Highly Productive Process Technologies of Cantilever-type Microprobe Arrays for Wafer Level Chip Testing

“…probe tips, the vertical type, based on the array from standing probe tips vertically [4,5,8,9], and the MEMS type, which forms probe tips by using micromachining technologies [10][11][12][13]. Until now, conventional cantilever-type probe cards have frequently been used, which are fabricated manually.…”

“…In general, they should be designed to have an overdrive of 100 μm at 4 gf contact force, and displacement up to the overdrive of 150 μm. In terms of design, probe beams and probe tips were designed to withstand 150 μm or higher overdrives, through cantilever-related formulas and simulations [9].…”

“…The fabrication process for a cantilever-type MEMS probe card with its microprobes is shown in Figure 2 [8,9]. The substrate for the fabrication of the probes was a 6-inch, p-type, (100) silicon wafer, with thickness of 650 μm.…”

MEMS-based Ni–B probe with enhanced mechanical properties for fine pitch testing

“…With the rapid growth in semiconductor technology for integrated circuit (IC) manufacturing processes, microelectromechanical systems (MEMS)-based probes play an important role in testing ICs on a wafer [1,2]. The waferlevel test is the first step in the device manufacturing process, where chips fabricated on a bare wafer are subjected to standardized tests by using the input/output (I/O) terminals of the chips in order to determine defective chips before the packaging process [3].…”

“…Under these conditions, Ni alloys, especially Ni-Co, are conventionally used for micro-probes because of their suitable properties and affordable fabrication processes, such as electroplating [2,[5][6][7][8][9][10]. However, since integration has increased continuously over the years, there is a growing need to find another material to meet the stringent requirements.…”