Wafer Cleaning with Die Gap Expansion and Ultrasonic Removal

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Solution Overview

Problem

Conventional wafer cleaning apparatuses face challenges in effectively removing foreign materials from gaps between dies, leading to increased cleaning time and structural complexity, along with coupling errors and potential damage due to inconsistent sealing ring coupling.

Innovation Solution

A wafer cleaning apparatus featuring a vacuum chuck unit, a ring cover unit, an expander module to widen gaps between dies, and a chucking module to restrain the ring cover unit, combined with an ultrasonic cleaning module for efficient cleaning solution application and ultrasonic vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional cleaning methods are used, then cleaning process is simple, but foreign materials in gaps between dies cannot be effectively removed and cleaning time increases

Engineering Contradiction:

Improvecleaning speedVSAvoidcleaning effectiveness

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent employs dynamic gap expansion by moving the retainer ring portion relative to the vacuum chuck unit to widen gaps between dies during cleaning. This dynamic adjustment allows cleaning solution to effectively reach foreign materials in gaps, improving cleaning effectiveness without extending cleaning time, thus resolving the contradiction between cleaning speed and cleaning effectiveness.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of gap width between dies by mechanically expanding the gap using the retainer ring portion. This parameter change enables the cleaning solution to access and remove foreign materials from gaps that were previously inaccessible, thereby improving cleaning effectiveness while maintaining efficient cleaning speed.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If sealing ring is coupled to rotary table, then sealing function is achieved, but coupling error occurs and processing solution permeates outside sealing ring causing damage

Engineering Contradiction:

Improvesealing performanceVSAvoidprocessing solution leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a retainer ring portion as an intermediary component between the sealing ring and the vacuum chuck unit. This intermediary structure provides a dedicated mounting interface that ensures accurate positioning and secure coupling, preventing processing solution from leaking outside the sealing ring and causing damage to external components.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The retainer ring portion acts as a protective intermediary that prevents direct coupling errors from causing damage. By providing a buffered interface, it cushions against misalignment and coupling errors, ensuring that even if coupling imperfections occur, the processing solution remains contained within the sealing ring boundary.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Stability of the object's composition

If wafer fixing module and sealing ring fixing module are installed, then wafer position stability and sealing ring fixation are improved, but apparatus structure becomes complicated and manufacturing cost increases

Engineering Contradiction:

Improveposition stabilityVSAvoidapparatus structure

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the sealing ring fixing function with the vacuum chuck unit by integrating the retainer ring portion directly into the vacuum chuck unit structure. This consolidation eliminates the need for a separate sealing ring fixing module, reducing apparatus structural complexity while maintaining secure fixation and position stability through the unified design.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The vacuum chuck unit is designed with multi-functionality, serving both as the wafer fixing mechanism and as the mounting structure for the sealing ring via the retainer ring portion. This universal design reduces the total number of components needed, simplifying the apparatus structure while maintaining the stability required for both wafer handling and sealing ring fixation.

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

This solution enhances cleaning performance by allowing easier removal of foreign materials from both die surfaces and gaps, reduces cleaning time, and simplifies the apparatus structure while maintaining wafer flatness and reducing defect rates.

Implementation Method 1

a vacuum chuck unit on which a wafer is mounted

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

an ultrasonic cleaning module for efficient cleaning solution application and ultrasonic vibration

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentUS12154819B2Wafer cleaning apparatus and method of controlling the same

Publication Date: 2024.11.26 ZEUS

AI summary

A wafer cleaning apparatus of the present invention includes a vacuum chuck unit on which a wafer is mounted, a ring cover unit facing a retainer ring portion of the wafer, an expander module installed to move the ring cover unit and configured to press the retainer ring portion toward the vacuum chuck unit such that a gap between dies of the wafer widens, and a chucking module installed in the vacuum chuck unit to restrain the ring cover unit pressed by the expander module to the vacuum chuck unit.