It is expected that the demand for pure electric vehicles (EVs) and hybrid vehicles (HEVs) will reach tens of millions of cars after 15 to 20 years. This will change the power module design and industry landscape. Toyota has led the evolution of power electronics packaging with its own hybrid vehicles. Other auto companies also followed closely, prompting Infineon, Danfoss, Semikron, and Fuji Electric to make advances in packaging technology. Moreover, the development of technology has brought benefits to related markets.
The traditional power module market is oriented towards the industrial and renewable energy fields and requires high reliability, long life, and high quality. Although very high added value and small amount of production are also the object of pursuit, the cost pressure is less. EVs and HEVs have been instrumental in the search for higher performance parameters such as large operating temperature ranges. This should also have positive significance for existing uses.
The power electronics industry now widely uses aluminum wire bonding technology, which is an abnormal phenomenon. If you choose a bonding method that can reduce the resistance, increase the thermal conductivity, and increase the lifetime, it is possible to achieve better performance. Wire bond is very fragile and may fall off due to thermal cycling, vibration, impact, etc.
Toyota uses aluminum ribbon bonding
One of the alternatives for aluminum wire bonding is aluminum ribbon bonding, which has now been adopted by Toyota. However, this method is also likely to be replaced by copper wire bonding. Copper wires can be bonded using standard packaging equipment, and the steps of connecting to the chip surface are simple. Moreover, due to the low resistance and high thermal conductivity of copper, the bonding effect can be maintained for a long period of time. SEMIKRON uses a flexible foil method. Other module manufacturers use a non-flexible foil and a DBC (direct bonded copper) substrate on the die.
Module manufacturers are exploring bonding methods that can adapt to higher output densities, temperatures, and thermal loads. Moreover, in order to reduce the chance of thermal cycling causing peeling, the coefficient of thermal expansion also needs to be maintained at a low level. SEMIKRON and Heraeus have developed a method for sintering on DBC using ultra-fine silver powder. However, this method takes a long time and it is necessary to evenly distribute the pressure of 30 MPa on the die, and the temperature must reach 250°C. Heraeus is currently evaluating nano silver powders that do not require high pressure and high temperatures. Moreover, there are now many companies that have launched nano-slurries that are shipped on foil, which are easier to transport and coat than gels and pastes. In addition, eutectic bonding using the high thermal resistance properties of copper-tin alloys is also an option, and this method has been adopted by Infineon's ".XT" power module. This method is to form a very thin layer of copper and tin on the DBC and place the die on it. Copper and tin mix at high temperatures to form high melting alloys.
The power module must also have a cooling system. After removing the sandwich between the die and the cooling system, the liquid will come into direct contact with the DBC. Toyota, Fuji Electric and Mitsubishi's hybrid vehicles have adopted this technology. Now, research into the cooling of microchannels has begun by embedding microtubes in cooling plates or DBCs. With this approach, products made from silicon and wide bandgap semiconductors can operate in higher temperatures.
Recently, the power module package must support new formats, such as PowerStack, more integrated components. These technological innovations for EV are gradually rewriting the pattern of the industry. Passive component manufacturers do not have technical experience in the fields of power module, packaging manufacturing and design. Therefore, Danfoss has taken part in such cooperation by adopting the cooperation with power module manufacturers. In addition, Infineon and Cybernetics are also working together to develop PowerStack technology.
Terminal configuration appears standardized trend
In the past, due to the small scale of production in the power electronics industry, in addition to several common module sizes, few standards have been widely adopted by the industry. Today, this situation is gradually changing. Fuji Electric is working with Infineon and SMT to study the pin configurations that make the modules compatible. With the direct cooperation between module manufacturers and automotive manufacturers, EV is setting off another technological revolution. This means that the industry structure of the automotive electronics sector has evolved compared to the clear division of labor in the past at the first and second levels.
Another evolution may come from the trend of ordering externally specialized package manufacturers. Now, most of the power module manufacturers are using the low labor costs in the Asia-Pacific region, so there is no need to subcontract any process externally. However, with the rapid expansion of the market, many companies such as the Philippines IQXprez are expected to consider entering the market as a contractor.
Precautions for daily maintenance of hydraulic cylinders
1. Regularly inspect the sealing components of the hydraulic cylinder, such as O-rings and gaskets, to ensure that they are intact and undamaged. If there is wear or aging, they should be replaced in a timely manner.
2. Regularly check the liquid level of the hydraulic cylinder and keep it within the specified range. If the liquid level is too low, add hydraulic oil in a timely manner.
3. Regularly inspect the connection parts of the hydraulic cylinder, such as oil pipes and joints, to ensure their tightness and reliability. If there is any looseness, it should be tightened in a timely manner.
4. Regularly clean the outer surface of the hydraulic cylinder to prevent dust, sand, and other debris from entering the interior of the cylinder and affecting its normal operation.
5. Regularly inspect the surface of the piston rod of the hydraulic cylinder, and promptly repair or replace it if there are scratches or wear.
6. Regularly inspect the hydraulic system of the hydraulic cylinder, and promptly handle any problems such as oil leakage or unstable pressure.
7. When the hydraulic cylinder is not in use for a long time, its hydraulic oil should be drained to avoid oil aging, deterioration, and affecting the normal operation of the hydraulic system.
8. When repairing or replacing hydraulic cylinders, attention should be paid to safety to avoid sudden movement or pressure release of the hydraulic cylinder, which may cause personal injury or equipment damage.
For Liugong Cylinder Seal Kit,For Liugong Swing Motor Seal Kit,Center Joint Seal Kit For Liugong,Center Joint Seal Kit Liugong
Safe Seal Technology Co., Ltd. , https://www.aprseal.com