COB LED Package Using General PCB and Resin Dome
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Solution Overview
Problem
Conventional Chip on Board (COB) packages using Metal Core Printed Circuit Boards (MCPCBs) are expensive due to high manufacturing costs and complex assembly structures, which hinder the widespread adoption of LED-based light sources in low-cost, high-efficiency applications.
Innovation Solution
A COB package utilizing a general PCB material with through holes and a dome structure made of resin to fix LED devices, where the through holes have a reflecting surface and the LED devices are in direct contact with a metallic chassis via submounts, enhancing heat radiation and light emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If MCPCB is used as substrate, then heat radiation effect is improved, but manufacturing cost increases
Solution Approach 1:
The substrate is divided into two functional parts: a general PCB providing electrical connection and a separate metal plate attached to the rear surface providing heat radiation. This segmentation allows each component to perform its specialized function while using cost-effective materials.
Solution Approach 2:
A resin layer acts as an intermediary bonding agent between the general PCB and the metal plate, enabling thermal transfer from the LED to the metal radiation surface while maintaining structural integrity and electrical insulation.
2Temperature
If support members are inserted in through holes, then heat radiation is improved, but assembly structure becomes complex
Solution Approach 1:
The support function and heat radiation function are merged into a single metal plate component. The metal plate simultaneously provides mechanical support for the LED, conducts heat away from the LED, and radiates heat to the environment, eliminating the need for separate support members.
Solution Approach 2:
The metal plate performs multiple functions: structural support, thermal conduction, and thermal radiation. This multi-functionality simplifies the overall assembly structure while maintaining effective heat management.
3Ease of manufacture
If general PCB material is used, then manufacturing cost is reduced, but heat radiation effect deteriorates
Solution Approach 1:
Different parts of the substrate system have different material properties optimized for their specific functions: the front surface uses general PCB material for cost-effectiveness and electrical properties, while the rear surface uses metal material for superior heat radiation.
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 significantly reduces manufacturing costs while improving heat radiation and light emission efficiency, enabling the production of high-quality LED-based light sources at lower costs.
Implementation Method 1
the through holes have a reflecting surface
Implementation Method 2
the LED devices are in direct contact with a metallic chassis via submounts, enhancing heat radiation
Data Source
AI summary
A Chip on Board (COB) package which can reduce the manufacturing costs by using a general PCB as a substrate, increase a heat radiation effect from a light source, thereby realizing a high quality light source at low costs, and a manufacturing method thereof. The COB package includes a board-like substrate with a circuit printed on a surface thereof, the substrate having a through hole. The package also includes a light source positioned in the through hole and including a submount and a dome structure made of resin, covering and fixing the light source to the substrate. The invention allows a good heat radiation effect by using the general PCB as the substrate, enabling manufacture of a high quality COB package at low costs. This in turn improves emission efficiency of the light source, ultimately realizing a high quality light source.