Schottky diodes are divided into two types of packages: wire and surface mount (chip type). Schottky diodes with leaded packages are generally used as high frequency and large current rectifier diodes, freewheeling diodes or maintenance diode applications. It has two package types: multi-tube type and pair-tube (dual diode) type. The Schottky pair of tubes has three types: common cathode (the negative stages of the two tubes are connected), common anode (the positive stages of the two tubes are connected) and series connection (the positive stage of one diode is connected to the negative stage of the other diode). Kind of lead out method. The Schottky diodes that are packaged on the surface have a variety of packaging types such as multi-tube, double-tube and triple-tube types, and there are A to 19 pin lead methods.
Schottky diodes have the advantages of high power switching frequency and reduced forward voltage, but their reverse breakdown field strength is relatively low, most of which are not higher than 60V, and the maximum is only about 100V, which limits its scope of application. Like in power transformer (SMPS) and power factor calibration (PFC) power supply circuits, freewheeling diodes of output power power switching components, high frequency rectifier diodes above 100V for secondary coils of transformers, RCD oil pressure buffer power supply circuits Choose 600V～1.2mV high-speed diodes and 600V diodes for PFC transformation, etc., and only fast repair epitaxial diodes (FRED) and ultra-rapid repair diodes (UFRD) can be used.
The reverse recovery time Trr of UFRD is also above 20ns. It is not necessary to consider the SMPS of 1MHz to 3MHz in industries such as space stations. Even if the hard power switch is 100kHz SMPS, because UFRD's on-off loss and switching loss are very large, the case temperature is very high, a large heat pipe radiator is used, and the volume and net weight of the SMPS are increased, which is not compatible with miniaturization and lightness. The development trend of globalization. Therefore, the development trend of high-voltage Schottky diodes above 100V has always been the subject of scientific research and the network hotspot of concern. In recent years, Schottky diodes have achieved groundbreaking progress. 150V and 200V high-voltage carbon-carbon composite diodes have already been sold, and Schottky diodes over 1kV made of new materials have also been developed and used for them. Introduced new vitality and charm.
The major drawbacks of Schottky diodes are their lower bias in the reverse direction and greater leakage current in the reverse direction. For example, Schottky diodes using silicon and metal materials as raw materials have the largest reverse bias rating. Only up to 50V, and the leakage current in the reverse direction is characterized by positive temperature, which is very easy to increase rapidly with the rise of temperature. Special attention should be paid to the hidden danger of heat uncontrollable in the practical design of the operation. In order to prevent the aforementioned problems, the reverse bias voltage of Schottky diodes in specific applications is much smaller than its rated current. However, the technology of Schottky diodes has also been developed, and the rated current of the reverse bias voltage can reach 200V.
The above explanation is the packaging method of Schottky diodes. I hope it will be helpful to you after reading it. If you want to know more about Schottky diodes, please contact customer service online or call our company's service Hotline (upper right corner of the website) for consultation, we will be happy to provide you with quality service!