LED Filament PCB Substrate Design for Mass Production
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Solution Overview
Problem
Existing LED filaments face high defect rates during manufacturing, high material costs, low manufacturing efficiency, and are prone to breakage due to brittle substrates like ceramic and glass, leading to unstable electrical connections and poor conductivity.
Innovation Solution
The use of a glass fiber PCB substrate with a connecting circuit and fluorescent glue layers of varying fluorescent agent content, allowing for uniform light emission and improved durability, along with a manufacturing process that eliminates the need for metal wires by directly connecting LED chips to the substrate, enhancing mechanical strength and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If ceramic, glass or sapphire substrates are used for LED filaments, then the substrate provides good electrical insulation and heat resistance, but the substrates are brittle and easy to break
Solution Approach 1:
The patent uses a glass fiber PCB substrate that combines organic resin matrix with inorganic glass fiber reinforcement, creating a composite material that provides both the heat resistance needed for LED operation and the mechanical flexibility to avoid breakage. This composite structure maintains the thermal properties required for LED filaments while eliminating the brittleness of pure ceramic or glass substrates.
2Reliability
If metal wires are used to power LED chips, then electrical connection is established, but the welding process increases manufacturing complexity and defect rates
Solution Approach 1:
The patent integrates the electrical connection function directly into the PCB substrate by fabricating copper traces and connection pads on the substrate surface. This merges the substrate's mechanical support function with the electrical connection function, eliminating the need for separate metal wire welding processes and reducing manufacturing complexity while maintaining reliable electrical connections to LED chips.
3Reliability
If traditional welding processes are used to connect LED chips to substrates, then electrical connections are formed, but manufacturing efficiency decreases and defect rates increase
Solution Approach 1:
The patent replaces the mechanical welding process with a direct bonding approach where LED chips are mounted and electrically connected to copper traces on the PCB substrate through processes such as reflow soldering or conductive adhesive bonding. This substitution eliminates complex wire bonding equipment and multiple welding steps, significantly improving manufacturing efficiency while maintaining connection reliability.
4Productivity
If PCB substrate is used instead of ceramic or glass, then manufacturing cost decreases and manufacturing efficiency improves, but heat dissipation capability must be maintained
Solution Approach 1:
The glass fiber PCB substrate combines an organic resin matrix with inorganic glass fiber reinforcement, creating a composite that provides both improved manufacturability and adequate heat dissipation. The glass fiber network within the composite structure serves as a thermal conduction pathway, while the overall PCB design can incorporate thermal vias and heat sinks to maintain heat dissipation performance comparable to traditional substrates.
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 results in a more stable, cost-effective, and efficient LED filament with improved durability and heat dissipation, suitable for mass production and various circuit arrangements, reducing defects and manufacturing costs while providing uniform light emission.
Implementation Method 1
a fluorescent glue layer provided outside the PCB substrate and the LED chips
Data Source
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AI summary
The present disclosure provides an LED filament and lamp, and a manufacturing process of an LED filament. The LED filament comprises a PCB substrate and a plurality of LED chips, a connecting circuit is provided on the PCB substrate, a positive pin and a negative pin are provided at the two ends of the connecting circuit, respectively, and each of the LED chips is electrically connected to the connecting circuit; and a fluorescent glue layer is provided outside the PCB substrate and the LED chips, and the positive pin and the negative pin are exposed from the fluorescent glue layer. The LED lamp comprises the LED filament. The manufacturing process of an LED filament enables manufacturing of an LED filament. For the LED filament and lamp, and the manufacturing process of an LED filament, a PCB substrate is used as a base material, a connecting circuit is fabricated on the PCB substrate, the connecting circuit is directly used for connecting an LED chip, and there is no necessity to perform welding by using wires, which reduces the manufacturing cost and improves the manufacturing efficiency and the manufacturing yield rate; and the present LED filament and the LED filament manufactured by this method have a more stable electrical connection structure, and are suitable for mass production.