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

Hao Yuan Chang, Wen Fung Pan, Meng Kai Shih, Yi Shao Lai

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


The probe card with ultra-long probing needles is specifically designed for probe testing of wafers that feature protruding housing for digital micromirror devices (DMD) for digital light processing (DLP) applications. Compared with a conventional short probing needle, an ultra-long probing needle leaves a smaller scrub mark on the pad during probe testing but it suffers the risk from buckling. In this work, three-dimensional finite element models were developed and validated by experiments for single conventional and ultra-long probing needles to analyze their mechanical responses during wafer-level probe testing. Following the Taguchi method, we conducted separate optimal geometric designs for an ultra-long probing needle with respect to the minimized scrub length and minimized buckling potential. It was found that a long beam length of the ultra-long probing needle is preferred in reducing both scrub length and buckling potential. A compromised design that considers minimizing scrub length and buckling potential conjointly but with different weightings was presented.

Original languageEnglish
Pages (from-to)556-563
Number of pages8
JournalMicroelectronics Reliability
Issue number4
Publication statusPublished - 2010 Apr

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Safety, Risk, Reliability and Quality
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering


Dive into the research topics of 'Geometric design for ultra-long needle probe card for digital light processing wafer testing'. Together they form a unique fingerprint.

Cite this