Invantest: Integrator WaferTest (igWT)

Products

Integrator WaferTest (igWT)

Premier cell controller for direct control of both tester and prober required for advanced manufacturing solutions and QA controls at wafer sort

Premier cell controller for wafer sort
The use of a cell controller (also known as a station controller) to automate and optimize wafer sort operations began with igWT in 1994. Since then, igWT has evolved to satisfy the requests and requirements of its expanding customer base. After many years of production use and continuous improvements, it continues to extend its lead in cell controller technology for semiconductor wafer sort.

With millions of dollars spent on expensive wafer sort equipment, the cost of semiconductor testing becomes a significant barrier to profitability. igWT offers a comprehensive suite of production solutions to minimize the cost of test at wafer sort while preventing quality exceptions.

Automatic Solutions for Immediate Benefits

Extensive set of retest solutions for minimizing retest
Extensive set of wafer stepping algorithms for increasing throughput
Adaptive test solutions to optimize test performance at each lot
Sampling and inline QA solutions for product reliability
Best practices for Known Good Die with multiple test passes
Automatic validation of the electrical integrity of probe contact to maximize yields
Online and offline, hard and soft bin quality assurance processes

Real-Time Controls

Advanced process controls and Visibility Report to drive Lean Manufacturing methods
Control of prober and tester on a die-by-die basis with immediate notification of production problems
Notification includes display of Out-of-Control Plan for immediate corrective action
Direct prober control to minimize the number of probe touchdowns
Limits the total touchdowns per die to avoid damage to pads
Multiple test passes and sub-passes
Extensive multi-pass process history
Avoids testing die discovered to be defective during upstream inspections
Retest can be avoided by resuming testing at last die tested after an interruption in production testing
Custom applications can be driven by die-level, wafer-level, or lot-level events
Manual control of probe stepping and test can be performed from the IG.WT graphical user interface
Updates the Navigator floor controller with cell status information for display in the floor controller

Yield Monitoring

Overall yield monitor with control chart identifies low yielding wafers in real-time
Built-in production monitors report problems as they occur to reduce rework and yield loss
Monitors include control limits that define the boundary between normal and abnormal events
At out of control events, monitors can be triggered to alarm, stop testing, display an Out-of-Control Action Plan, auto probe clean, or auto retest

Setup Management

Auto retrieves setup information from a central repository of setup files
Auto downloads setup parameters to the prober and loads the test program
Lets the user choose a subset of wafers from the lot for testing
Custom data files can be included in the lot setup window
Custom data is included in IG.WT data files
Probe z-height can be automatically set to reduce the risk of damaging the probe card
Probe card planarity is automatically checked to accept or reject probe cards before use
Probe card layout can be user defined

Standardization Across Different Equipment

Standard IG.WT user interface across all equipment
Same production operations across all equipment
Same test data files across all equipment
Qualified to run on most test and probe equipment

Data Integrity

Complete wafer history with results maps are maintained by IG.WT independent of tester
No data is lost if tester crashes
Production results from are test cells are stored in standard INF and SINF data file format
INF and SINF data files include complete wafer result maps from every test pass
Wafer result maps can also be exported to SEMI G81/G85 XML or other custom formats