Stacked LED Module Layout for Compact Vehicle Headlamps

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing light emitting diode modules for vehicle headlamps face issues with increased size due to multiple LEDs, leading to restricted design flexibility and space limitations, which is exacerbated by the need for multiple driving controllers, resulting in larger peripheral lighting apparatuses.

Innovation Solution

The light emitting diode module is designed with multiple substrates, where the light emitting diode packages and driving controllers are separated onto different substrates, allowing for a compact printed circuit board configuration with improved heat dissipation and reduced size, enabling flexible design and precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional LED module structure is used, then the structure is simple, but the light extraction efficiency is insufficient and color uniformity is poor

Engineering Contradiction:
Improvestructural simplicityVSAvoidlight extraction efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent transitions from a conventional planar LED structure to a three-dimensional stacked configuration where a second substrate with additional light-emitting units is positioned above the first substrate. This vertical dimensionality change increases the total light output and extraction efficiency without complicating the manufacturing process, as each substrate layer can be independently fabricated using standard processes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements a nested structure where the second substrate is positioned within the vertical space above the first substrate, creating a compact stacked arrangement. The housing encapsulates both substrates in a nested configuration, maximizing light extraction efficiency while maintaining a compact form factor that does not significantly increase the overall footprint.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If a conventional LED module structure is used, then the manufacturing process is simple, but the color uniformity is poor

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcolor uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent divides the LED module into multiple independent substrate layers, each containing light-emitting units with identical chip configurations. This segmentation allows each substrate to be manufactured separately with consistent color characteristics, and when stacked, the uniformity is maintained across the entire module. The first and second substrates are manufactured using the same process parameters, ensuring color consistency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality control by ensuring that each substrate layer has uniform light-emitting unit distribution and identical chip specifications within its layer. The housing structure provides localized support and positioning for each substrate, maintaining precise alignment and consistent optical properties across the entire stacked structure, thereby achieving uniform color output.

Inventive Principle:
Principle #3Local quality

3Reliability

If the housing inner wall is highly reflective, then light extraction efficiency improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidhousing manufacturing precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent modifies the optical parameters of the housing inner wall by incorporating a reflective layer with high reflectivity (90% or more). This parameter change allows the housing to achieve superior light extraction efficiency without requiring extremely tight manufacturing tolerances, as the reflective property compensates for minor variations in housing geometry and alignment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The housing is constructed as a composite structure combining a base material (such as plastic or metal) with a reflective layer (such as metal coating or reflective paint). This composite approach provides both structural integrity and high reflectivity, achieving excellent light extraction efficiency while maintaining manufacturing feasibility with standard tolerances.

Inventive Principle:
Principle #40Composite materials

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 reduces the printed circuit board size by up to 1/4, enhances heat dissipation, and allows for increased design freedom and precision in vehicle headlamp applications, while maintaining effective control over multiple light sources.

Implementation Method 1

a light-emitting unit for generating and emitting light

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

a reflective layer formed on the inner wall of the housing in a region facing the light-emitting unit

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4657527A2Light-emitting diode module and system comprising same
Publication Date: 2025.12.03 SEOUL SEMICONDUCTOR
  • EP4657527A2 patent drawingFigure 1~2A
  • EP4657527A2 patent drawingFigure 2B~2C
  • EP4657527A2 patent drawingFigure 3A~3B

AI summary

A light-emitting diode module according to one embodiment comprises a first substrate and a second substrate positioned in one direction of the first substrate, wherein the first substrate includes a light-emitting diode package on which at least one light-emitting unit for generating and emitting light is disposed, the light-emitting diode package includes a dam portion for encompassing the light-emitting unit, and the first substrate and the second substrate include overlapping regions that overlap each other.