FPC board is thin, light, thin and has large capacity, and is currently widely used. With the continuous development of electronic equipment, heat dissipation has become a key factor restricting the performance and reliability of FPC boards in high-power application scenarios. Traditional FPC board heat dissipation methods often have limited effects. The main problems are:
Irrational flow channel design and too small flow rate cannot achieve effective cooling and heat dissipation
Large resistance at the corner of the flow channel, resulting in slow flow rate, and the coolant cannot be replaced and cooled in time
Short service life and easy to delaminate and disintegrate, resulting in serious quality accidents caused by coolant injection. Therefore, the development of a new FPC board with flexible heat dissipation flow channel has important practical significance.
In order to solve the limitations of traditional FPC heat dissipation methods, the Flex Plus R&D team has developed a more efficient flexible heat dissipation solution-a new FPC with flow channel heat dissipation through innovative design and continuous optimization. It not only has better heat dissipation performance, but also maintains lightweight and flexibility, adapts to the needs of complex electronic equipment, and significantly improves the reliability and performance of the equipment.
The core content of the R&D of the new FPC board project with channel heat dissipation:
Through the research on the problems existing in the project, the direction to solve the problems is established. After analysis, the project team believes that:
The poor adhesion of the bonding surface causes poor disintegration of the Flex PCB, so the bonding strength of the roughened copper surface and the adhesive is the key. When combining circuits, the baking process after hot pressing is particularly critical. It must be baked at 160℃ for 2 hours to completely solidify the thermosetting adhesive to achieve the best bonding strength. Such FPC board can withstand the impact of the flow rate of the flow channel and the thermal shock of 260℃.
The slow flow rate is mainly due to the unreasonable flow channel design of the FPC board. First, the cross-sectional area of the flow channel is too narrow, causing the cooling coolant to fail to flow normally and cannot be replaced in time, thus failing to meet the technical requirements of heat dissipation. Secondly, because the flow channel is curved, there will be greater resistance when the coolant flows, causing the pressure in the flow channel to increase, increasing the risk of Flex circuit board disintegration, and causing the slow flow rate to fail to meet the technical requirements of cooling and heat dissipation. Therefore, it is particularly important to reasonably design the shape of the flow channel and optimize the flow channel corners.
Main technical points:
Line design optimization: The line corners are optimized by chamfering with a radius of 0.5mm to reduce resistance to achieve the best flow channel flow parameters.
Flow channel design: Reasonably design the shape, size and layout of the flow channel to improve the heat dissipation efficiency. The cross-section of the flow channel adopts an elliptical design instead of a rectangular shape to increase the flow rate and flow rate.
Manufacturing process: 1. The mold embossing process of the flow channel ellipse 2. The process of hot pressing and combination of fixtures.
The technology of developing a new FPC board with flexible heat dissipation flow channel, double-sided roughening of pure copper, selection of hot pressing adhesive suitable for the product size, 8oz copper foil and PI substrate are combined for 150℃ lamination, and then the original copper foil is made by hot pressing with parameters of 180℃, 160 seconds, 100Kgf and baking and curing at 160℃ for 2 hours.
The copper foil is then dry filmed, developed, etched, and stripped. The initial circuit of the product is formed, the protective film is embossed, and the protective film is hot pressed with a fixture again to prevent the flow channel from deformation. The hot-pressed FPC board is placed on a special fixture for baking and curing to prevent the flow channel from deformation. The developed heat dissipation flow channel FPC board can reduce functional problems in terminal use and improve production efficiency and yield rate.
Choose Flex Plus for your flexible PCB needs
At Flex Plus, we can provide customers with more cost-effective flexible circuit board. We know that heat can negatively affect flexible PCBs, so we are very careful during the prototyping and engineering stages to ensure that the flexible PCB provided to customers are suitable for the required application and do not overheat.
Check out our flexible PCB capabilities today. If you have any questions or would like a free quote, please feel free to contact us.
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