Rotational Wafer Testing with Edge-Extended Translator

Solution Overview

Problem

Current semiconductor test equipment lacks the ability to efficiently test an entire wafer at once, requiring accurate and costly probing systems to step across the wafer, leading to increased complexity and production costs.

Innovation Solution

A full-wafer contact test apparatus with a rotationally accessed edge-extended wafer translator and caliper-style contact block, allowing for removably attached wafers to be tested using a rotation stage and zero or low insertion force sockets for efficient electrical contact across the wafer's edge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If probes are stepped from one location on the wafer to another during testing, then the entire wafer can be tested, but the probing system requires very accurate placement and high accuracy probing systems dedicated to each wafer, increasing cost and complexity

Engineering Contradiction:

Improvewafer testing efficiencyVSAvoidprobing system complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The wafer is divided into multiple test locations that can be accessed sequentially through rotational movement. The probe card remains stationary while the wafer rotates to bring different contact points into the testing zone, eliminating the need for complex probe stepping mechanisms.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces rotational movement in a third dimension to access different contact points on the wafer. Instead of moving probes across the wafer surface in the planar dimension, the wafer itself rotates to bring contacts into position, simplifying the probing system architecture.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Productivity

If probes are stepped from one location on the wafer to another during testing, then the entire wafer can be tested, but very accurate placement of probes onto the wafer is required, increasing the cost of producing devices

Engineering Contradiction:

Improvewafer testing efficiencyVSAvoiddevice production cost

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The wafer is divided into multiple test locations that can be accessed sequentially through rotational movement. The probe card remains stationary while the wafer rotates to bring different contact points into the testing zone, eliminating the need for complex probe stepping mechanisms.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces complex mechanical probe stepping and positioning systems with a simpler rotational mounting mechanism. The wafer rotates on a precision axis while the probe card remains stationary, reducing manufacturing complexity and cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a high accuracy probing system is dedicated to each wafer under test, then accurate electrical contact can be achieved, but the cost and complexity of these probing systems has a large impact on the overall cost of producing the devices

Engineering Contradiction:

Improveelectrical contact accuracyVSAvoidprobing system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The wafer is divided into multiple test locations that can be accessed sequentially through rotational movement. The probe card remains stationary while the wafer rotates to bring different contact points into the testing zone, eliminating the need for complex probe stepping mechanisms.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A single stationary probe card can test multiple locations on the wafer by utilizing rotational movement. This universal testing approach eliminates the need for dedicated high-accuracy probing systems for each wafer, reducing overall system complexity and cost while maintaining testing accuracy.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables efficient and cost-effective testing of entire wafers by allowing rotational access to electrical contacts, reducing the complexity and cost of probing systems while maintaining high accuracy.

Implementation Method 1

removable attachment of wafer and edge-extended wafer translator is accomplished by pressure differential

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

the caliper-style contact block is a zero insertion force socket

Methodology Applied

Scientific EffectZero insertion force:

Implementation Method 3

the caliper-style contact block is a low insertion force socket

Methodology Applied

Scientific EffectLow insertion force:

Data Source

PatentUS7498800B1Methods and apparatus for rotationally accessed tester interface

Publication Date: 2009.03.03 TRANSLARITY INC

AI summary

A wafer/wafer translator pair in the attached state, with the wafer translator extending beyond the outer circumference of the wafer, is disposed on a rotation stage. At least one surface of the edge-extended wafer translator, in a peripheral annular region, provides contact pads electrically coupled to corresponding pads on the wafer, and a caliper-style contact block, operable to move perpendicularly the edge-extended wafer translator is positioned such the contact pads of the annular region may be electrically engaged with the contact block. After electrical communication between the wafer and the contact block, the contact block moves to a disengagement position, the rotation stage rotates the wafer/wafer translator pair to a new position and the contact block may then move into engagement with different contact pads in the annular region.