FOLYSKY（WuHan） LTD.
hotline：
027-88111056
technical：
13387504731
FOLYSKY（WuHan） LTD.
Application and Development Trends of LED Ceramic Substrates:
Ceramic heat dissipation substrates may vary in appearance due to different needs and applications. On the other hand, various ceramic substrates can also be distinguished based on different product manufacturing methods.
In the application of LTCC heat dissipation substrates in LED products, most of them are large-sized high-power and small-sized low-power products. Basically, the appearance is mostly concave cup shaped, and according to the needs of the client, two types of heat dissipation substrates can be made: wire rack and no wire rack. The concave cup shape is mainly designed for packaging process using a simpler dispensing method, and the edge of the concave cup is used as a path for light reflection, However, LTCC itself is limited by process factors, making it difficult to prepare products into small sizes. Furthermore, the use of thick film production circuits makes the circuit accuracy insufficient to meet the requirements of high-power and small-sized LED products.
HTCC, which has a similar appearance to the LTCC process, has not yet been widely used in the LED heat dissipation substrate. This is mainly because HTCC uses high temperature drying and hardening at 1300~1600 ℃, which increases production costs and relatively high HTCC substrate costs. Therefore, it faces a more rigorous test for striving to move towards the low-cost trend in the LED industry.
On the other hand, DBC and DPC not only differ in appearance from LTCC/HTCC, but also have different packaging methods for LED products. DBC/DPC are all planar heat dissipation substrates, and planar heat dissipation substrates can be customized to prepare metal circuits for processing, and then cut into small-sized products according to customer needs, supplemented by eutectic/cladding technology, combined with highly skilled fluorescent powder coating technology and advanced packaging technology casting molding, which can significantly improve the LED's luminous efficiency. However, due to process capacity limitations, DBC products have a maximum circuit resolution of only 150-300um. If special fine circuit products are to be made, grinding must be used to reduce the thickness of the copper layer. However, this has caused problems such as difficulty in controlling surface flatness and increasing additional costs, making DBC products less suitable for the application of high circuit accuracy and high flatness requirements in eutectic/cladding processes.
DPC utilizes thin film micro lithography technology to prepare metal circuit processing, which has the characteristics of high precision and high surface smoothness of the circuit. It is very suitable for the process of cladding/eutectic bonding, and can significantly reduce the cross-sectional area of LED products' wires, thereby improving the efficiency of heat dissipation.
Conclusion:
After comparing the production process, characteristics, and application scope of various ceramic substrates mentioned above, individual differences can be clearly compared. Among them, LTCC heat dissipation substrates have been widely used in the LED industry. However, in order to reduce the sintering temperature, LTCC added glass materials to the materials, reducing the overall thermal conductivity to between 2-3W/mK, which is even lower than other ceramic substrates. Furthermore, LTCC uses screen printing to print circuits, which leads to insufficient precision in line diameter and width, as well as issues with screen tension, resulting in insufficient circuit accuracy and poor surface smoothness. In addition, multi-layer lamination sintering and substrate shrinkage ratio need to be considered, which does not meet the requirements of high-power and small-sized products. Therefore, the current application in the LED industry is mainly focused on high-power and large-sized products or low-power products. Similar to the LTCC process, HTCC is dried and hardened at high temperatures ranging from 1300 to 1600 ℃, resulting in higher production costs. Considering cost, it is currently rarely used in the LED industry, and HTCC has the same problems as LTCC, and is not suitable for high-power and small-sized LED products. On the other hand, in order to achieve good adhesion between the copper layer of DBC and the ceramic substrate, it is necessary to use high-temperature melting at 1065~1085 ℃, which incurs high manufacturing costs and makes it difficult to solve the problem of micro pores between the substrate and the Cu plate, which greatly affects the production capacity and yield of DBC products; Furthermore, in order to produce thin circuits, special treatment methods must be used to reduce the thickness of the copper layer, which results in poor surface smoothness. If the product is used in the eutectic/cladding process of LED products, it is relatively strict. On the contrary, DPC products use a vacuum sputtering method using thin film technology to deposit thin copper, and then use a yellow light micro shadow process to complete the circuit. Therefore, the wire diameter width is 10~50um, and can even be finer. The surface flatness is high (<0.3um), and the alignment accuracy error value of the circuit is only ± 1.0%, completely avoiding problems such as shrinkage ratio, screen layout, surface flatness, and high manufacturing costs.
The current trend in the development of LED products can be observed from the recent power and size observations of LED products published by major LED packaging manufacturers. High power and small size products are currently the focus of the LED industry's development, and ceramic heat dissipation substrates are used as the way for their LED crystal heat dissipation. Therefore, ceramic heat dissipation substrates have become a crucial part of high-power and small-sized LED product structures. Although ceramic substrates such as LTCC, HTCC, DBC, and DPC have been widely used and studied, in the field of high-power LED ceramic heat dissipation, DPC can be said to be the most suitable ceramic heat dissipation substrate for the development of high-power and small-sized LEDs in the current development trend.
Under the development trend of high efficiency, high product quality requirements, and high-power LED ceramic substrates, the selection of thin film process ceramic substrates with high heat dissipation effect and precision will become a trend to overcome the bottleneck that thick film process products cannot break through at present. Expected thin film ceramic substrates will gradually be applied to high-power LEDs and reach economic scale with the rapid development of high-power LEDs. At this time, regardless of high-power LED chips, thin film ceramic heat dissipation substrates, packaging process costs, etc., will be significantly reduced, thereby accelerating the quantification of high-power LED products.
Follow us
customer service
