Carbon Fiber Base Plate for Vacuum Heating Apparatus

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional semiconductor substrate heating apparatuses experience filament distortion and non-uniform substrate temperature due to excessive thermal expansion of the base plate at high temperatures, leading to potential short-circuiting and insulation errors.

Innovation Solution

A heating apparatus with a base plate made of carbon fibers to minimize thermal expansion, combined with high-emissivity carbon heat reflecting plates to reduce temperature differences and prevent filament distortion, ensuring long-term stability and efficient heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a molybdenum base plate is used to fix the filament, then the base plate can provide structural support, but the base plate undergoes thermal expansion at high temperatures causing distortion of support columns and filament bending

Engineering Contradiction:

Improvestructural support capabilityVSAvoidfilament position accuracy

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The base plate material is changed from molybdenum to a composite material containing carbon fibers. This parameter change in material composition fundamentally alters the thermal expansion characteristics, allowing the base plate to maintain dimensional stability at high temperatures while retaining structural support capability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The base plate is constructed using a composite material incorporating carbon fibers. This composite structure combines the structural strength needed for support with the low thermal expansion properties of carbon fibers, resolving the contradiction between mechanical strength and dimensional stability at high temperatures.

Inventive Principle:

Principle #40Composite materials

2Temperature

If the base plate undergoes thermal expansion, then the support columns spread outward, but this applies excessive force to the filament causing it to bend and potentially short-circuit

Engineering Contradiction:

Improveheating temperatureVSAvoidelectrical stability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The material parameter of the base plate is changed to a carbon fiber composite with near-zero thermal expansion coefficient. This allows the system to operate at high temperatures (2000°C or more) without the base plate expanding, thereby preventing excessive force on the filament and maintaining electrical stability.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If the temperature difference between upper and lower surfaces of the base plate is large, then heating efficiency is maintained, but the base plate warps and projects toward the conductive heater

Engineering Contradiction:

Improveheating efficiencyVSAvoidbase plate flatness

Core Design Contradiction:

Use of energy by moving objectVSShape

Solution Approach 1:

The base plate material is changed to a carbon fiber composite with extremely low thermal expansion. This allows the base plate to withstand large temperature differences between upper and lower surfaces without warping, maintaining both heating efficiency and structural flatness simultaneously.

Inventive Principle:

Principle #35Parameter changes

4Strength

If molybdenum base plate is used at high temperatures, then structural support is provided, but sublimated molybdenum attaches to insulating glass members causing insulation errors

Engineering Contradiction:

Improvestructural support capabilityVSAvoidmolybdenum sublimation

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The base plate material is changed from molybdenum to a carbon fiber composite. This parameter change eliminates the sublimation issue entirely, as carbon fibers remain stable at the operating temperatures without sublimating and contaminating the insulating glass members.

Inventive Principle:

Principle #35Parameter changes

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 solution prevents filament distortion and maintains uniform substrate temperature, enhancing semiconductor element productivity and reducing the risk of insulation errors while maintaining heating efficiency.

Implementation Method 1

a filament arranged in a vacuum heating vessel and connected to a filament power supply to generate thermoelectrons

Methodology Applied

Scientific EffectThermionic emission: Thermionic Emission

Implementation Method 2

an acceleration power supply which accelerates the thermoelectrons between the filament and a conductive heater

Methodology Applied

Scientific EffectElectrostatic acceleration: Electric Field

Implementation Method 3

the thermoelectrons generated by the filament are caused to collide against the conductive heater to heat the conductive heater

Methodology Applied

Scientific EffectElectron impact heating: Electron Beam

Implementation Method 4

the base plate comprises a plate body having a carbon fiber

Methodology Applied

Scientific EffectThermal expansion resistance: Zero Thermal Expansion

Data Source

PatentUS8032015B2Heating apparatus, heating method, and semiconductor device manufacturing method

Publication Date: 2011.10.04 CANON ANELVA CORP

AI summary

A heating apparatus including a filament arranged in a vacuum heating vessel comprises a base plate arranged in the vacuum heating vessel to fix the filament at a predetermined position with respect to a conductive heater forming one surface of the vacuum heating vessel. The base plate comprises a plate body having a carbon fiber.