Wafer Thickness Measurement Using Pivoting Sensor and Counter-Holder

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Solution Overview

Problem

Conventional systems fail to accurately measure the thickness of thin-walled, brittle wafer sheets produced in industrial baking machines due to their high temperature and brittle nature, leading to inefficiencies and quality issues in wafer production.

Innovation Solution

A device with a movable measuring sensor and a counter-holder forms a measuring gap, where the sensor scans the wafer sheet's thickness using a pivoting arm with a damper to prevent overshooting, and a conveyor system ensures precise measurement and adaptation to varying wafer thicknesses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional measuring systems are used for hot, brittle wafer sheets, then the measurement process is simple, but the wafer sheets are damaged or measurement accuracy is poor due to high temperature and brittleness

Engineering Contradiction:
Improvethickness measurement accuracyVSAvoiddamage to brittle wafer sheets
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A counter-holder is introduced as an intermediary component between the measuring sensor and the wafer sheet. The counter-holder provides a stable, temperature-resistant reference surface that can withstand the hot wafer sheets while the measuring sensor remains separate and protected. This mediator allows accurate measurement without direct contact between the sensor and the fragile hot wafer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces conventional contact-based mechanical measuring systems with a specialized setup where a pivoting arm with damper controls the measuring sensor's contact. This substitution reduces mechanical impact and damage to brittle hot wafers while maintaining measurement capability through controlled, minimal-contact measurement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If the measuring sensor is made rigid for stable measurement, then measurement stability is improved, but the device cannot adapt to varying wafer thicknesses

Engineering Contradiction:
Improvemeasurement stabilityVSAvoidadaptation to varying wafer thickness
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The measuring sensor is designed with a pivoting arm that can dynamically adjust its position and angle. The arm pivots about an axis and can be damped to control movement, allowing the sensor to adapt to different wafer thicknesses while maintaining measurement stability through controlled motion rather than rigid fixation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the positional parameters of the measuring sensor by allowing the pivoting arm to adjust its angle and position. This enables the measurement system to adapt to varying wafer thicknesses by modifying the sensor's geometric parameters rather than using a fixed rigid structure.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the measuring sensor contacts the wafer sheet directly for measurement, then the measurement structure is simple, but the brittle wafer sheet is damaged

Engineering Contradiction:
Improvemeasurement structure simplicityVSAvoidwafer sheet integrity
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The counter-holder acts as a mediator that the wafer sheet contacts instead of the measuring sensor directly. The wafer sheet rests on the counter-holder's run-out bevel while the measuring sensor approaches from the opposite side, reducing direct contact stress and preventing damage to the brittle wafer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pivoting arm is equipped with a damper that provides cushioning before the measuring sensor contacts the wafer. This damping mechanism prevents excessive force or impact during measurement, protecting the brittle wafer from damage while enabling successful thickness measurement.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Productivity

If conventional thickness measurement is performed on continuously moving wafers, then production efficiency is maintained, but accurate measurement of thin-walled brittle structures is difficult

Engineering Contradiction:
Improvecontinuous production efficiencyVSAvoidthickness measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The wafer sheet is guided onto the counter-holder's run-out bevel before the actual measurement occurs. This preliminary positioning action stabilizes the moving wafer and establishes a reference surface, enabling accurate measurement during continuous movement without requiring the production line to stop.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates a reference measurement surface using the counter-holder that replicates the ideal measurement condition. By having the wafer contact this reference surface during continuous movement, the system achieves accurate thickness measurement without interrupting production flow.

Inventive Principle:
Principle #26Copying

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

The device enables accurate thickness measurement of wafer sheets, improving production efficiency and quality by ensuring consistent product thickness, reducing raw material usage, and preventing damage during measurement.

Implementation Method 1

a damper is provided for damping oscillations of the swivel arm

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3854213B1Device for measuring the thickness of thin-walled brittle wafers
Publication Date: 2023.06.07 BUHLER FOOD EQUIP GMBH
  • EP3854213B1 patent drawingFigure 1
  • EP3854213B1 patent drawingFigure 2
  • EP3854213B1 patent drawingFigure 3

AI summary

Manufacturing plant and device for measuring the thickness of thin-walled, brittle wafer sheets (22) which are continuously conveyed through a measuring gap (1) during the measurement, comprising: a first wafer sheet conveyor (2) with a conveying surface (3) on which the wafer sheets (22) are transported to and from the measuring gap (1), a measuring sensor (4) movably arranged for thickness measurement, wherein the measuring sensor (4) forms one side of the measuring gap (1), wherein the measuring sensor (4) has a first inlet ramp (5) and wherein the measuring sensor (4) has a pivot arm (7) pivotally mounted about a pivot axis (6) and a sensor (8) configured to detect the movement of the pivot arm (7), a counter-holder (9) rigidly arranged during the measurement, wherein the counter-holder (9) forms the other side of the measuring gap (1), wherein the counter-holder (9) has a second inlet ramp (10).- and a second waffle sheet conveyor (11) that conveys the waffle sheet (22) along a conveying direction (16) through the measuring gap (1).