Surface Heater Insulating Layer for Leakage Current Prevention

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Solution Overview

Problem

Conventional electric range surface heaters face safety issues due to leakage currents and increased risk of short circuits at high temperatures, primarily because the substrate's resistance decreases, leading to potential electric shocks and heater module breakdowns.

Innovation Solution

Incorporating an insulating layer with high specific resistance, made from materials like Boron nitride, Aluminium nitride, or Silicon nitride, between the substrate and the heater layer, along with a binder such as Glass frit and lanthanide oxides, to maintain high resistance and prevent short circuits, while using the Low Temperature Ceramics Co-firing (LTCC) process for manufacturing to enhance adhesion and simplify the process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the substrate is heated to high temperature, then the heating performance is improved, but the specific resistance of the substrate decreases causing leakage current and safety issues

Engineering Contradiction:
Improveheating temperatureVSAvoidelectrical insulation reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

An insulating layer is introduced as an intermediary between the substrate and the heater layer. This insulating layer has high specific resistance and prevents direct electrical contact between the substrate and heater, thereby blocking leakage current while allowing thermal energy to pass through for heating purposes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses a composite structure consisting of the substrate, insulating layer, and heater layer. The insulating layer is made of materials with high specific resistance such as ceramic powders or glass frit, creating a composite material system that maintains electrical insulation at high temperatures while enabling thermal conduction for heating.

Inventive Principle:
Principle #40Composite materials

2Temperature

If the substrate resistance decreases at high temperature, then thermal activation increases, but the risk of short circuit in the heating element increases

Engineering Contradiction:
Improveoperating temperatureVSAvoidshort circuit risk
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The insulating layer serves as a protective barrier between the substrate and the heater layer. Even when the substrate resistance decreases due to thermal activation, the insulating layer prevents electrical short circuits by maintaining electrical insulation, thus protecting the heating element from short circuit risks.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulating layer is applied in advance before the heating process to provide preemptive protection against short circuits. This prior protective measure ensures that even if the substrate becomes conductive at high temperatures, the short circuit risk is mitigated before it can cause damage.

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

3Reliability

If a coating layer is applied to prevent leakage current, then user safety is improved, but the manufacturing process complexity increases

Engineering Contradiction:
Improveuser safetyVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The insulating layer is integrated into the existing manufacturing process by combining the application of the insulating layer with the heater layer formation process. Both layers are applied and sintered in a unified process sequence, merging what could be separate steps into a single manufacturing flow, thus reducing overall process complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent controls the resistance and thickness parameters of the insulating layer to optimize its performance. By adjusting these parameters, the insulating layer provides sufficient protection against leakage current while minimizing the added complexity to the manufacturing process.

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

This configuration effectively prevents leakage currents and short circuits, ensuring user safety and stability of the surface heater and electric range, while also improving manufacturing productivity and adhesive strength, and allowing control over the resistance of the insulating layer.

Implementation Method 1

the glass, etc., which is a substrate, sharply decreases in specific resistance at a high temperature due to an inherent characteristic of the material... When the temperature rises, a lattice vibration becomes active due to an increase in thermal activation of an insulator lattice, thereby increasing the electrical conductivity of the insulator (decreasing the resistivity)

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

a plate type heater formed on a substrate, which generates a heat by supplying the electricity to the heating element

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Implementation Method 3

an electrical conduction in the insulator to which the glass, etc. belongs is mainly generated by a lattice vibration or phonon. When the temperature rises, a lattice vibration becomes active due to an increase in thermal activation of an insulator lattice

Methodology Applied
Scientific EffectLattice vibration: Vibration

Implementation Method 4

an electrical conduction in the insulator to which the glass, etc. belongs is mainly generated by a lattice vibration or phonon

Methodology Applied
Scientific EffectPhonon conduction: Conduction (electrical)

Implementation Method 5

a binder such as Glass frit and lanthanide oxides, to maintain high resistance and prevent short circuits, while using the Low Temperature Ceramics Co-firing (LTCC) process for manufacturing to enhance adhesion

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3364715B1The surface heater, the electric range comprising the same, and the manufacturing method of the same
Publication Date: 2021.10.27 LG ELECTRONICS INC
  • EP3364715B1 patent drawingFigure 1~3
  • EP3364715B1 patent drawingFigure 4~5
  • EP3364715B1 patent drawingFigure 6~7

AI summary

The present disclosure relates to a method and an apparatus for managing an input power supply of an electronic device. A method for managing an input power supply of an electronic device according to one embodiment includes measuring an input voltage that is input from an input power supply; generating an approximate fundamental wave with respect to the input voltage using a maximum value of the input voltage and a preset fundamental wave table; calculating at least one of an index value and an index variance with respect to the input power supply using a difference value between the input voltage and the approximate fundamental wave; and determining a kind of the input power supply on the basis of at least one of the index value and the index variance. In accordance with the present disclosure as described above, there is an advantage in which a kind of the input power supply may accurately be determined for a short time without affecting controlling of basic functions of the electronic device.