Application of laser spot cutting on spring contact probe for semiconductor package inspection. (1st December 2017)

• Record Type: Journal Article
• Authors: Lee, Dongkyoung; Cho, Jungdon; Kim, Chan Ho; Lee, Seung Hwan
• Is Part Of: Optics & laser technology. Volume 97(2017)
• Page Start: 90
• Page End: 96
• Publication Date: 2017-12-01
• Subjects: Laser spot cutting -- Spring contact probe -- Plunger -- Semiconductor package inspection -- Beryllium copper; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2017.06.005
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Application of laser spot cutting on spring contact probe is studied for the first time. Laser-material interaction characteristics are investigated. Laser parameters applicable to laser spot cutting are selected. Feasibility of laser spot cutting on spring contact probe is tested. Abstract: A packaged semiconductor has to be electrically tested to make sure they are free of any manufacturing defects. The test interface, typically employed between a Printed Circuit Board and the semiconductor devices, consists of densely populated Spring Contact Probe (SCP). A standard SCP typically consists of a plunger, a barrel, and an internal spring. Among these components, plungers are manufactured by a stamping process. After stamping, plunger connecting arms need to be cut into pieces. Currently, mechanical cutting has been used. However, it may damage to the body of plungers due to the mechanical force engaged at the cutting point. Therefore, laser spot cutting is considered to solve this problem. The plunger arm is in the shape of a rectangular beam, 50 μm (H) × 90 μm (W). The plunger material used for this research is gold coated beryllium copper. Laser parameters, such as power and elapsed time, have been selected to study laser spot cutting. Laser material interaction characteristics such as a crater size, material removal zone, ablation depth, ablation threshold, and full penetration are observed. Furthermore, a carefully chosen laser parameter ( E total = 1000 mJ ) to test feasibility of laser spot cutting are applied. The result show that laser spot cutting can be applied to cut SCP.