Edge Type Backlight Unit Thermal Hardener Heat Dissipation

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Solution Overview

Problem

The existing edge type backlight units face inefficiencies in heat dissipation due to non-uniform surface contact between the metal printed circuit board (PCB) and the thermal interface material, leading to reduced LED efficiency and lifespan, as well as potential deformation of the light guide plate and optical sheets from excessive heat.

Innovation Solution

An edge type backlight unit is designed with a metal bracket that is coated with a thermal hardener, allowing for uniform surface contact with the PCB, which enhances heat dissipation by using a thermosetting polymer material and a manufacturing method that ensures even coating and attachment of the thermal hardener to the PCB.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If thermal interface material is manually applied to achieve heat dissipation, then heat dissipation function is provided, but uniformity of application is reduced and gaps are generated

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoiduniformity of thermal interface material application

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The patent replaces the manual mechanical application process of thermal interface material with an automated coating system. The coating apparatus uses a coating head that moves along the metal PCB to deposit thermal conductive paste uniformly, eliminating manual application inconsistencies and gaps.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses the existing screw fastening process to simultaneously achieve both mechanical attachment and uniform thermal interface material application. The coating head is positioned to coat the thermal interface material before the PCB is fastened with screws, so the screw fastening process serves dual purposes: securing the components and ensuring uniform contact pressure for heat dissipation.

Inventive Principle:

Principle #25Self-service

2Strength

If metal PCB is fastened to cover bottom using screws, then mechanical attachment is achieved, but surface contact uniformity is reduced

Engineering Contradiction:

Improvemechanical attachment strengthVSAvoidsurface contact uniformity

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent applies the thermal interface material to the metal PCB before the screw fastening process. The coating head deposits the thermal conductive paste on the PCB surface in advance, ensuring that when the screws are tightened, the uniform pre-applied material layer is compressed evenly between the PCB and cover bottom, achieving both strong mechanical attachment and uniform thermal contact.

Inventive Principle:

Principle #10Preliminary action

3Power

If LED is used as light source, then efficiency and luminance are improved, but heat generation increases reducing LED lifespan

Engineering Contradiction:

ImproveLED luminance efficiencyVSAvoidLED operating temperature

Core Design Contradiction:

PowerVSTemperature

Solution Approach 1:

The patent introduces thermal interface material (thermal conductive paste) as an intermediary substance between the metal PCB and the cover bottom. This intermediary material fills micro-gaps and enhances thermal conduction, acting as a heat transfer medium that efficiently carries away LED-generated heat, thereby maintaining lower LED operating temperatures while preserving high luminance efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts heat from the LED system by providing dedicated heat dissipation pathways. The metal PCB with improved thermal contact to the cover bottom serves as a heat extraction mechanism, continuously removing excess thermal energy from the LED to maintain optimal operating temperature and extend lifespan.

Inventive Principle:

Principle #2Taking out (Extraction)

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 results in improved heat dissipation, reducing the average temperature of the light source, PCB, and metal bracket by approximately 8.97°C, 6.57°C, and 5.43°C respectively, compared to using a thermal interface material, thereby extending the lifespan of the light source and preventing heat-related deformations.

Implementation Method 1

a thermal hardener formed between the printed circuit board and the metal bracket

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS8764267B2Edge type backlight unit and method for manufacturing the same

Publication Date: 2014.07.01 LG DISPLAY CO LTD

AI summary

An edge type backlight unit and a method for manufacturing the same are disclosed. The edge type backlight unit includes light sources for providing light, a printed circuit board (PCB) on which the light sources are mounted, a metal bracket that contacts the printed circuit board and dissipates heat of the printed circuit board, and a thermal hardener formed between the printed circuit board and the metal bracket. The printed circuit board supplies an electrical signal for driving the light sources to the light sources.