Wafer Test

Most foundries provide wafers already probed to a set of DC parameters at room temperature to ensure they meet a basic subset of the package-part specification. Beyond this basic set of tests, more rigorous testing is often needed to meet specifications requiring die to be 100 percent probed, identify and segregate devices with higher performance levels and guarantee that parts will perform to a certain specification level.

STS has extensive experience and in-house expertise to design test programs and perform the wafer testing and sorting using our state-of-the-art Accretech 8” and 12” wafer probers. We design vertical probe cards and develop programs for a wide range of circuits, including RF devices running as fast as 6 GHz and high-speed digital ICs with clock speeds as high as 10 GB/sec. Key features of the STS wafer test and sort services include thermal control, multi-site probing, bake retention, bumped wafer probing, in-line or off-line inking, auto alignment and probe mark and wafer ID inspection.

The STS Advantage

  • More than four decades of experience serving commercial, military, and aerospace markets
  • 300 mm (12 inch) and 200 mm (8 inch) capabilities
  • Expertise in test program development
  • RF speeds up to 6 GHz
  • High-speed digital ICs up to 10 GB/sec
  • Active DUT temperature regulation
  • High precision and operational excellence
  • Automatic loader helps minimize contamination


  • Aerospace and defense
  • Industrial
  • Communications
  • Networking
  • Medical

Typical Applications

  • MOSFETs and JFETs
  • IGBTs
  • Diodes
  • Discrete analog devices


Test Handlers
  • Epson NS-8040 IC Handler (2)
  • Synax SC3100 quad site test handlers (2)
  • Synax SC1211 dual site test handlers (2)
Wafer Probers
  • Accretech UF3000EX
  • Accretech UF200