LED Light Emitting Unit with Integrated Heat Sink

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Solution Overview

Problem

Current light emitting units face limitations in increasing light output while maintaining cost-effectiveness, as they struggle with heat dissipation and temperature control, particularly when multiple LED chips are connected in series, leading to restricted light output and increased costs due to the need for additional heat sinks and precise alignment.

Innovation Solution

The proposed solution involves a light emitting unit with a heat transfer plate made of aluminum, an insulating layer with a filler of higher thermal conductivity, and a color conversion unit, along with a base substrate that minimizes thermal expansion differences, allowing for efficient heat radiation and increased light output without the need for multiple heat sinks, thereby reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple LED chips are connected in series to increase light output, then the light output increases, but the heat dissipation becomes more difficult and temperature control deteriorates

Engineering Contradiction:
Improvelight outputVSAvoidtemperature control
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent combines multiple heat dissipation functions into a single integrated heat sink structure. The heat sink includes a base portion that contacts the LED chip and a plate portion that extends from the base, creating a unified thermal management system that efficiently dissipates heat from multiple LED chips connected in series without requiring separate heat sinks for each chip.

Inventive Principle:
Principle #5Merging (Combining)

2Temperature

If additional heat sinks are added to manage heat from multiple LED chips, then temperature control improves, but the device complexity and cost increase

Engineering Contradiction:
Improvetemperature controlVSAvoidstructure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges multiple heat dissipation functions into a single integrated heat sink structure. The heat sink includes a base portion that contacts the LED chip and a plate portion that extends from the base, creating a unified thermal management system that efficiently dissipates heat from multiple LED chips connected in series without requiring separate heat sinks for each chip.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The heat sink structure serves multiple functions simultaneously: it provides thermal management for multiple LED chips, acts as a mounting substrate, and facilitates heat dissipation through its extended plate portion. This multi-functional design eliminates the need for separate components and reduces overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Illumination intensity

If precise alignment is implemented for multiple LED chips, then light output uniformity improves, but manufacturing precision requirements and costs increase

Engineering Contradiction:
Improvelight output uniformityVSAvoidalignment precision
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent incorporates alignment marks and positioning structures during the preliminary stages of manufacturing. The substrate includes predefined alignment features that guide the placement of LED chips, ensuring proper alignment before the actual mounting process. This preliminary preparation simplifies the manufacturing process and reduces the need for high-precision alignment during assembly.

Inventive Principle:
Principle #10Preliminary action

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 enhances heat radiation capabilities and increases light output while reducing costs by allowing for more efficient heat management and alignment, enabling higher power input without overheating the LED chips.

Implementation Method 1

a light emitting unit with a heat transfer plate made of aluminum

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

an insulating layer with a filler of higher thermal conductivity

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2565951B1Light emitting unit and illuminating apparatus
Publication Date: 2019.07.31 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2565951B1 patent drawingFigure 1A~1C
  • EP2565951B1 patent drawingFigure 2~3
  • EP2565951B1 patent drawingFigure 4

AI summary

Provided is lead frame in which a wiring pattern supported by a support piece inside of a one-pitch outer frame section comprises a plurality of base units, each of which comprises a die pad on which a solid-state light emitting element is mounted, a heat sink extending from die pad so as to surround die pad electrically connected to one electrode of the element, and a lead electrically connected to the other electrode of the element. Lead of one base unit among adjacent base units and heat sink of the other base unit are coupled and electrically connected in series. Increase in temperature of the element is inhibited, light output is increased, and cost of a light emitting unit in which a plurality of solid-state light emitting elements connected in series are used is reduced. Also provided are wiring board, light emitting unit, and illuminating apparatus.