Low-Profile LED Module PCB Thermal Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to develop a low-cost, effective packaging method for LED arrays that efficiently dissipates heat and is suitable for outdoor use, while maintaining a water-tight seal and minimizing profile thickness to fit in existing lighting fixtures.
Innovation Solution
A low-profile outdoor lighting module is created with a molded-plastic cover and printed circuit board (PCB) forming a water-tight seal, where LED dies are mounted on a substrate with landing pads connecting to the PCB, and a highly reflective sheet is used between the lens and PCB to direct light, along with drive electronics and a thermal interface material for heat management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If LED dies are enclosed in a traditional package with multiple components (heat sink, power supply circuitry, optical components), then the LED array can be effectively used in lighting modules, but the profile height increases and manufacturing complexity increases
Solution Approach 1:
The patent combines multiple previously separate components into a single integrated PCB structure. The PCB now serves as both the mounting substrate for LED dies and the heat sink, eliminating the need for separate heat sink and power supply components. This merging reduces the overall package complexity while maintaining functionality.
Solution Approach 2:
The PCB is designed to perform multiple functions simultaneously: it serves as the electrical connection substrate, the heat dissipation structure, and the mechanical support framework. This multi-functionality eliminates the need for separate dedicated components, thereby reducing packaging complexity and profile height.
2Temperature
If traditional packaging components are used, then the LED array can be effectively cooled and powered, but the profile thickness increases preventing installation in existing fixtures
Solution Approach 1:
The heat dissipation function is merged into the PCB structure itself. The PCB incorporates thermal pathways and heat dissipation features directly into its design, eliminating the need for separate heat sink components that would increase profile thickness.
Solution Approach 2:
The patent transitions from a three-dimensional stacked arrangement of separate components to a planar two-dimensional integration on the PCB. By spreading heat dissipation structures across the surface area of the PCB rather than stacking them vertically, the profile thickness is reduced while maintaining heat dissipation capability.
3Reliability
If a water-tight seal is formed between molded-plastic cover and PCB, then outdoor durability is improved, but manufacturing complexity increases
Solution Approach 1:
The PCB structure is designed with integrated sealing features that form the water-tight seal without requiring additional sealing components or complex assembly procedures. The PCB itself provides the sealing function through its structural design, making the manufacturing process simpler while maintaining reliability.
4Reliability
If landing pads on substrate connect to contact pads on PCB, then electrical connection is achieved, but the assembly precision requirement increases
Solution Approach 1:
The PCB contact pads are pre-positioned and pre-aligned during PCB manufacturing before the LED substrate is attached. This preliminary positioning ensures that when the substrate is mounted, the landing pads align with the contact pads with minimal tolerance requirements, reducing the precision needed during final assembly.
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 enables a compact, weatherized, and efficient LED lighting module that can be easily mounted on heat sinks, effectively dissipating heat and providing a wide range of lighting options with reduced operational costs and improved durability.
Implementation Method 1
A highly reflective sheet is disposed between the planar lower surface of the lens and bottom of the indentation in the upper surface
Implementation Method 2
A thermal interface material can be applied to the bottom surface of the substrate so that the upper surface of the heat sink contacts the thermal interface material
Implementation Method 3
A light emitting diode (LED) is a solid state device that converts electrical energy to light
Implementation Method 4
Light is emitted from active layers of semiconductor material sandwiched between oppositely doped layers when a voltage is applied across the doped layers. A layer of silicone in which phosphor particles is embedded is typically disposed over the LED dies. Light emitted from the LED dies is absorbed by the phosphor particles, and is re-emitted by the phosphor particles so that the re-emitted light has a wider band of wavelengths
Data Source
AI summary
A low-profile lighting module with light-emitting diodes (LEDs) has a water-tight seal between a molded-plastic cover and a printed circuit board (PCB). A substrate with the LEDs fits up into an indentation in the lower surface of the PCB. Landing pads on the top of the substrate attach to contact pads in the indentation that are extensions of a conductor of the PCB which is electrically coupled through the landing pads to the LEDs. A lens with a curved optical portion surrounded by a flat lip fits into another indentation on the upper surface of the PCB. A highly reflective sheet is disposed between the planar lower surface of the lens and bottom of the indentation in the upper surface. A double-sided adhesive sheet is disposed under the inside surface of the molded-plastic cover and over both the upper surface of the PCB and the flat lip of the lens.