The packaging materials of LED display refer to various materials used to wrap and protect LED chips, as well as to connect and fix LED chips to the substrate.
The selection of these materials has an important impact on the performance, reliability and life of LED display.
The following is a detailed introduction to the packaging materials of LED display:
I. Classification of packaging materials
The packaging materials of LED display can be mainly divided into the following categories:
1. Substrate materials:
- Metal substrates: such as aluminum substrates (Aluminum Base Plate) and copper substrates (Copper Base Plate). These materials have good thermal conductivity, which helps the LED chip to dissipate heat and improve the stability and life of the LED display.
- Ceramic substrates: such as alumina (Al2O3), aluminum nitride (AlN), etc. Ceramic substrates have excellent insulation, high strength and good thermal conductivity, and are particularly suitable for packaging high-power LEDs.
- Composite substrates: such as aluminum silicon carbide (Al/SiC) substrates, which combine the advantages of metal and ceramic, have the significant advantages of low raw material cost, high thermal conductivity, low density and good plasticity.
- Other substrates: such as silicon substrates, epoxy molding compound (EMC), silicon molding compound (SMC), etc., these materials are also used in specific applications.
2. Die-bonding interconnection layer materials:
- Conductive silver glue: Currently the most widely used die-bonding interconnection material, it is popular because of its mature technology and high thermal conductivity.
- Insulating glue: It is divided into high thermal conductivity insulating glue and low thermal conductivity insulating glue, mainly used for low-power LED devices.
- Tin paste and gold-tin alloy: Mainly used for high-power LED devices, its thermal conductivity is better than conductive silver glue, but the process is complicated and the cost is high.
3. Potting materials:
- Epoxy resin: Traditional potting material, with good insulation, sealing and light transmission performance, but poor thermal stress matching with the internal LED device.
- Silicone gel: In recent years, it has gradually replaced epoxy resin as the mainstream potting material, because of its strong thermal conductivity and UV resistance, and good mechanical properties.
II. Considerations for packaging material selection
When selecting packaging materials for LED display screens, the following factors need to be considered:
1. Thermal performance: including parameters such as the thermal expansion coefficient and thermal conductivity of the material to ensure that the thermal performance between the packaging materials matches and avoid failure of LED devices caused by uneven temperature distribution.
2. Reliability: The packaging material should have good weather resistance, corrosion resistance and mechanical strength to ensure that the LED display screen can work stably in various environments.
3. Cost: Under the premise of ensuring performance, low-cost materials should be selected as much as possible to reduce production costs.
4. Processability: The processing performance and process complexity of the packaging material are also one of the factors that need to be considered when selecting.
III. Packaging technology
The packaging technology of LED display screens mainly includes SMD packaging, GOB packaging and COB packaging.
These packaging technologies have their own characteristics and are suitable for different application scenarios and needs.
For example, SMD packaging is suitable for small-pitch LED display screens; GOB packaging and COB packaging perform well in large-size, high-brightness LED display screens.
In summary, there are many kinds of packaging materials for LED displays, and the selection needs to be based on a comprehensive consideration of multiple factors such as specific application requirements, performance requirements, and cost considerations.
At the same time, with the continuous advancement of technology and the continuous innovation of materials, the packaging materials and packaging technologies of LED displays will continue to develop and improve.