In the many viewpoints of the chip, the liquid crystal panel, and the arrangement of various electronic components, the author feels that the place where "it is really work" is the heat dissipation measure. The use of heat pipes, heat sinks, soaking plates, etc., allows parts that are prone to heat to release heat. Each product uses its own characteristics, reflecting the developer's design ideas.
Now, a materials company is working hard to add new methods to these cooling measures. This company is the Xicun pottery industry that develops ceramic materials. The company's proposed cooling measures are based on the high thermal emissivity of ceramic circuit boards.
Cooling measure consultant, ThermalDesignLaboratory representative director Guo Feng Shang Shu said that the heat propagation mode has three forms: “heat conductionâ€, “convection†and “heat radiationâ€. The propagation of lattice vibration and the movement of free electrons in the metal belong to “heat conductionâ€. The heat transfer of fluid motion belongs to "convection", and heat transfer through electromagnetic waves is "thermal radiation". The method developed by Nishimura Ceramics is to use the infrared radiation of ceramic materials to dissipate heat.
The third method to improve the heat dissipation performance of components
The heat radiation heat dissipation method has the advantage that heat can be released when the casing is sealed and thin, and heat cannot be transferred by convection. Some technicians have known this advantage for a long time, but there are very few precedents for full use. However, according to Nishimura Ceramics, LED lighting products that have recently used heat radiation have increased. Among them, a Japanese lighting appliance company applied it to various applications ranging from large-scale LED lighting fixtures such as light projectors to small lamps such as desk lamps.
By using heat radiation to dissipate heat, the heat dissipation efficiency of the emitter can be improved without using a cooling fan. The use of a cooling fan eliminates the risk of failure (the risk of the fan being unable to dissipate due to some kind of failure), and because there is no need for multiple fins, it does not accumulate dust, eliminating the need for cleaning. In the manufacture of the desk lamp, the ultra-thin design of the outer casing near the light source is successfully realized by using heat radiation to dissipate heat.
Interestingly, whether it is a large-scale product or a small product, Nishimura Ceramics provides the same ceramic circuit board to lighting equipment companies. The ceramic circuit board is a horizontally long hexagon with a length of 55 mm × a width of 30 mm and a thickness of about 6 mm. The multi-chip LED module is fixed to the circuit board by screws. High-power LED modules with a maximum power of 19W. Large products use multiple screws to secure the LED module to the ceramic circuit board, and one for small products. The material of the ceramic circuit board is alumina with a purity of 99.7%, and the heat radiation rate is 0.97. The surface is smooth, the average roughness is 0.5μm, and the LED module is directly fixed to the surface of the board by screws.
Compared with metal circuit boards and printed circuit boards, ceramic circuit boards are hindered by high cost. However, if the mass production effect can be improved by the generalization of the ceramic circuit board, the increase in the cost can be suppressed to some extent. This requires an increase in mass production, but as of now, mass production has not yet begun, because companies are jealous of the high cost of ceramic circuit boards.
In response to this situation, Nishimura said that after using ceramic circuit boards, the total cost of heat sinks such as circuit boards and heat sinks for mounting LED modules can be reduced, and it is planned to use such heat dissipation costs as a selling point. The reason why the company is so confident is that the lighting equipment companies that use the company's products have compared the ceramic circuit board products and the products with the traditional heat dissipation design, and considered the total cost, and chose the ceramic circuit board without exception. . The idea of ​​whether the total cost of compression can be popularized will be closely followed by the author. Perhaps, it is possible to predict the degree of popularity by whether the shape of the LED lighting fixture is increased.
Piezoelectric ceramic disc
Quick delivery
High performance
Application: flow meter measurement
There are many kinds of USF used in closed pipeline according to the measuring principle, and the most commonly used are propagation time method and Doppler method. Among them, time difference ultrasonic flowmeter is used to measure fluid flow by the principle that the time difference of sound wave propagating downstream and countercurrent is proportional to the velocity of fluid flow. It is widely used in raw water measurement of rivers, rivers and reservoirs, process flow detection of petrochemical products, water consumption measurement of production process and other fields. According to practical application, time-difference ultrasonic flowmeter can be divided into portable time-difference ultrasonic flowmeter, fixed time-difference ultrasonic flowmeter and time-difference gas ultrasonic flowmeter.
Ultrasonic flow-meters use at least two transducers aligned so that ultrasonic pulses travel across the flow of liquid or gas in a pipe at a known angle to the flow.
Technical data:
Electromechanical coupling coefficient Kp: > 0.62
Dielectric Loss tg δ: <2%
Nominal Piezo discs for ultrasonic flowmeter:
OD14.2*1MHz PZT-51
OD14.6*1MHz PZT-51
OD15*1MHz PSnN-5
OD15*2MHz PSnN-5
OD20*1MHz PSnN-5OD20*2MHz PSnN-5
OD15*1MHz PZT-51
OD15*2MHz PZT-51
OD20*1MHz PZT-51OD20*2MHz PZT-51
Size, Frequency and Electrode on request.
Piezoelectric Discs For Flowmeter Sensor
Piezoelectric Ceramic Disc,Piezoelectric Discs For Flowmeter Sensor
Zibo Yuhai Electronic Ceramic Co., Ltd. , https://www.yhpiezo.com