Design and Fabrication of Highly Manufacturable Microelectromechanical Systems Test Sockets for Ball Grid Array Integrated Circuit Packages

Abstract

We have developed two types of microelectromechanical systems (MEMS) test sockets for the ball grid array (BGA) integrated circuit (IC) packages. The fabricated MEMS test sockets have simple structures, easy fabrication processes, low contact forces, and rapid prototyping and cost-effective processes. In the case of the cantilever-array-type test socket, we optimized the length, width, and thickness of the cantilever appropriate for a 121 ball square BGA IC package test. The contact force is 1.3 mN (1 g force ≈ 1 mN) for each cantilever with a length of 425 µm, a width of 150 µm, and a thickness of 10 µm at a deflection of 100 µm. The mesh-type test socket has a different maximum deflection value in accordance with the contact position. The average contact resistance is 0.73 Ω and the maximum signal path resistance is 18 Ω for the two types of MEMS test sockets. The fabricated MEMS test sockets are suitable for an actual BGA IC package test.