Integrated Wafer Thinning and Etching With a Stiff Outer Ring

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Solution Overview

Problem

Wafers face damage risks and productivity losses during delivery between grinding and etching apparatuses due to mechanical strength reduction and separate processing steps.

Innovation Solution

A wafer processing apparatus with integrated grinding, cleaning, and etching units, where the grinding wheel thins the wafer's inner region, leaving a stiff outer ring, and the etching unit removes strain from within this ring, eliminating the need for separate etching apparatuses and reducing handling time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the wafer is ground to thin down the inner region, then the wafer thickness is reduced, but the mechanical strength of the wafer is reduced making it prone to damage during delivery

Engineering Contradiction:

Improvewafer thicknessVSAvoidmechanical strength of wafer

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The wafer is divided into two functional regions: a thinned inner region for device integration and a thick outer circumferential ring-shaped stiff portion for mechanical support. This segmentation allows the wafer to simultaneously achieve reduced thickness and maintained strength during handling.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If the wafer is delivered between separate grinding apparatus and etching apparatus, then the processing steps can be performed separately, but the wafer may be damaged during delivery and productivity is reduced due to loss time

Engineering Contradiction:

Improveseparate processing stepsVSAvoidproductivity

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The grinding unit and etching unit are integrated into a single wafer processing apparatus. The ground wafer is held on the chuck table and the etching liquid is supplied to the ground surface without removing the wafer from the apparatus, eliminating delivery time and damage risk while maintaining separate functional zones for grinding and etching.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If the wafer is delivered between separate grinding apparatus and etching apparatus, then the processing steps can be performed separately, but the loss time occurs when the wafer moves between apparatuses

Engineering Contradiction:

Improveseparate processing stepsVSAvoiddelivery time

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

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

Prevents wafer damage and increases productivity by integrating processing steps, reducing handling time and eliminating the need for separate etching apparatuses.

Implementation Method 1

a grinding unit having a rotatable grinding wheel with an annular array of grindstones mounted thereon for grinding a surface of the wafer held on the chuck table

Methodology Applied

Scientific EffectAbrasion: Abrasion

Implementation Method 2

an etching unit for removing a strain from the ground surface of the wafer, in which the etching unit supplies an etching liquid to the inner region of the wafer inward of the outer circumferential ring-shaped stiff portion of the wafer to thereby remove a strain from the ground surface of the wafer

Methodology Applied

Scientific EffectChemical etching:

Implementation Method 3

a chuck table for holding the wafer thereon

Methodology Applied

Scientific EffectSuction: Suction

Data Source

PatentUS20240177999A1Wafer processing apparatus

Publication Date: 2024.05.30 DISCO CORP

AI summary

A wafer processing apparatus includes a chuck table for holding the wafer thereon, a grinding unit having a rotatable grinding wheel with an annular array of grindstones mounted thereon for grinding a surface of the wafer, a cleaning unit for cleaning the wafer that has been ground, and an etching unit for removing a strain from the ground surface of the wafer. The grinding wheel is smaller in diameter than the wafer, enabling the grindstones mounted on the grinding wheel to thin down an inner region of the wafer that includes the ground surface, leaving an outer circumferential ring-shaped stiff portion on the wafer. The etching unit supplies an etching liquid to the inner region of the wafer inward of the outer circumferential ring-shaped stiff portion of the wafer for thereby removing a strain from the ground surface of the wafer.