Test Prexa™Series

The latest wafer prober with advanced features and high productivity

Prexa™ is a fully automated and most advanced wafer prober series with innovative features including the latest optic system, new algorithms to enable error/assist reduction, and expansive automation capabilities.
The Prexa™ platform offers solutions for various customer needs that are drawing attention lately, including thermal control during device testing and high load control of the stage for memory devices.


Prexa™, the next-generation 300mm wafer prober full of advanced functions, was developed with a new platform.

In addition to process scaling, 3D stacking is drawing the industry’s attention as it enables leading-edge packaging that integrates multiple devices and/or heterogeneous devices. Its implementation necessitates a wafer testing process with reliable KGD* performance, which requires advanced features for wafer probers.

While inheriting a number of key technologies from the Precio™ series, the Prexa™ wafer prober also adopts innovative functions and features—including error/assist reduction and enhanced automation—to achieve higher productivity than its predecessors.


  • Automation of operations including setups

  • Error/assist reduction and high-accuracy contact enabled by the latest optic system and new algorithms

  • High-speed inspection of probe tips and probe marks

  • Software structure designed to enhance customer support

KGD: Known Good Die. It refers to bare chips (or bare dies) that have been fully tested and assured to be defect-free before being placed into their packages.


Prexa™ MS is a 300mm fully automated wafer prober that has the advanced features of Prexa™ as well as essential capabilities to perform wafer testing for memory devices. Memory devices today—most notably advanced DRAMs—tend to have increasing numbers of test pins and heat generation in device testing.

Prexa™ MS features exceptional load-bearing capacity of up to 1,000 kg (optional), achieving accurate contact with excellent load control. In addition, the system’s endothermic feature controls the heat dissipation corresponding to high heat generating device, enabling full-wafer contact testing of future memory devices.

Product comparison

Prexa™ MS
Prexa MS
Wafer size
 200*,300  200*,300
Availability  New  New
Stage technology  Linear motor  Linear motor
XY probing
 ±1.5*,±1.8  ±0.8
Z probing
 ±2.5*,±5.0  ±2.5*,±5.0
Probing force
 300,450*  600,1000*
Optical system  ASU-SP/BCU-FL  ASU-SP/BCU-FL
Operation system  Windows+PLC  Windows+PLC
   *Available as an option  *Available as an option