Porous Pad Grinding Machine Integrating Rough and Finish Operations

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Solution Overview

Problem

Existing grinding machines require separate devices for rough and finish grinding of semiconductor wafers and similar substrates, leading to inefficiencies in terms of economic efficiency and surface quality due to fine strains caused by brittle fracture during rough grinding.

Innovation Solution

A compact grinding machine that integrates a porous pad with fine pores and a gel-like slurry storing portion, where the porous pad contains superabrasives at its outer circumferential portion, allowing for both rough and finish grinding using a single grinding means by adjusting the pressing force to control the flow of the gel-like slurry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a grinding wheel is used for rough grinding, then rough grinding can be performed, but fine strains are generated on the ground surface due to brittle fracture

Engineering Contradiction:

Improverough grinding capabilityVSAvoidsurface quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent merges the rough grinding function and finish grinding function into a single porous pad assembly. The porous pad contains superabrasives for rough grinding while also allowing gel-like slurry to flow through its pores for finish grinding, eliminating the need for separate grinding wheel and porous pad devices.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The porous pad serves multiple functions: it acts as a grinding wheel for rough grinding using embedded superabrasives, and simultaneously serves as a carrier for gel-like slurry that provides finish grinding capability. This multi-functional design allows one device to perform both rough and finish grinding operations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If separate grinding devices are used for rough grinding and finish grinding, then each function can be optimized, but device complexity and economic efficiency are reduced

Engineering Contradiction:

Improvesurface qualityVSAvoidnumber of grinding devices

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the previously separate grinding wheel and porous pad into a single integrated porous pad assembly. The porous pad contains superabrasives for rough grinding and allows gel-like slurry to flow through its pores for finish grinding, eliminating the need for separate grinding wheel and porous pad devices.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Manufacturing precision

If gel-like slurry flows out from porous pad, then finish grinding can be performed, but the porous pad must be kept wet

Engineering Contradiction:

Improvefinish grinding capabilityVSAvoidmoisture control

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The porous pad structure enables automatic gel-like slurry delivery to the workpiece surface through capillary action. The gel-like slurry is supplied to the porous pad and automatically flows out through its fine pores to the workpiece surface, eliminating the need for external water supply systems or manual moisture control during finish grinding.

Inventive Principle:

Principle #25Self-service

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 both rough and finish grinding operations with a single machine, reducing the need for separate devices and minimizing surface strains through the use of superabrasives in the gel-like slurry, thereby improving the economic efficiency and surface quality of the grinding process.

Implementation Method 1

a porous pad having a large number of fine pores opposed to the workpiece held on the holding table, and gel-like slurry storing portion provided on the porous pad so as to store gel-like slurry therein

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

the porous pad contains superabrasives at least at an outer circumferential portion

Methodology Applied

Scientific EffectAbrasion: Abrasion

Implementation Method 3

water supply means for supplying water between the porous pad and the workpiece

Methodology Applied

Scientific EffectLubrication: Lubrication

Data Source

PatentUS8142259B2Grinding machine and method

Publication Date: 2012.03.27 DISCO CORP

AI summary

A grinding machine includes a holding table adapted to hold a workpiece, a grinding unit operative to grind the workpiece held on the holding piece, and a grinding unit transfer mechanism operative to shift the grinding unit in a direction coming close to or moving away from the workpiece. The grinding unit includes a porous pad having fine pores opposed to the workpiece, a gel-like slurry storing portion provided on the porous pad so as to store a gel-like slurry therein, and a water supply unit to supply water between the porous pad and the workpiece. The porous pad contains relatively larger superabrasives at least at an outer circumferential portion. The fine pores of the porous pad have a diameter greater than that of relatively small superabrasives contained in the gel-like slurry.