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INSPECTION, MEASUREMENT, AND TEST

19.6 FINAL MANUFACTURING

Evaluation and Time-to- Time-to- Time-to-profit Maturity in
purchase market volume the market
Needs Be ahead of Ramp Maximize
assessment market window production profitability
Requirement Characterize Automated test Minimize COT
defined device cell Overall equip-
Test system Win design-ins Correlation to ment efficiency
strategy to application standard Best business
Solution Improve model
Volume definition repeatability
Planning
Reduce
Development guardband

Test system
delivery

Time
FIGURE 19.2 Test adding value in all product phases.

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capable of providing manufacturing value added to material.” A stand-alone test system alone is not
capable of meeting this requirement, as the test system alone is not capable of handling and moving
the devices through test process steps. In order to do that, the test system needs to be integrated with
a materials handling system. The combination of a test system and a materials handling system meets
the SEMI definition of a processing agent, and is commonly called a test cell.
Accomplishing the integration of a test system with a materials handling system requires consid-
eration of several important software, electrical, and mechanical interfaces internal to the cell. The
device electromechanical interface provides a connection between the device and the tester mea-
surement resources. This includes a DUT board, plus a device contactor for a package test or a probe
tower and a probe card for the wafer level test. The tester/materials handler mechanical interface pro-
vides a solid physical docking connection between the tester and the materials handler. The tester/
materials handler software interface provides a software communications path to synchronize the
movement and presentation of a device and the tester program execution. There are also major inter-
faces outside of the cell. The human interface provides a way for the human to operate the test cell.
Lastly, the factory host interface provides a software connection to the factory host. This allows pro-
gram and processing of data information to be provided from a factory controller.
Correlation and Repeatability. In order to verify a manufacturing test process, the results must be
repeatable, statistically significant, and able to correlate to other systems performing the same test
functions. Repeatability verifies the results will be the same to within a margin. The statistical sig-
nificance of the results allows the use of a common process control statistical analysis to prove the
manufacturing test process is stable. A stable system can then be correlated with other stable systems
to allow material to be processed across several systems, or even across different factories. Correlation
allows comparison and verification of the results across test processes and has two major components.

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SEMI E40-0703, Standard for Processing Management.

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