3results about How to "Avoid thermal resistance" patented technology

This invention discloses a high thermal conductivity semiconductor packaging substrate and its preparation method, relating to the field of electronic materials technology. The method includes the following steps: mixing composite aluminum nitride powder with a sintering aid, ball milling, drying, and pressing into shape; sintering under high temperature and high pressure in a nitrogen atmosphere to obtain an aluminum nitride ceramic substrate; washing and drying the aluminum nitride ceramic substrate; covering both sides of the aluminum nitride ceramic substrate with copper foil, laying active solder between the aluminum nitride ceramic substrate and the copper foil, and then connecting them by vacuum brazing to obtain the semiconductor packaging substrate; the composite aluminum nitride powder is composed of aluminum nitride powder and modified aluminum nitride powder in a mass ratio of (6~8):(2~4). The semiconductor packaging substrate prepared by this method has excellent interfacial compatibility, effectively reduces interfacial thermal stress, and has good thermal conductivity.

The application discloses a whole pouring method and structure of a blast furnace hearth instead of cooling wall, wherein the inner side of a furnace shell is directly provided with a lining formed by pouring high-thermal-conductivity unshaped refractory material; a plurality of holes are formed in the furnace shell, and cooling elements are arranged in the holes; one end of the cooling elements is embedded in and penetrates through the lining and is in close contact with the lining, so that the cooling wall is cancelled, air gap thermal resistance is avoided, the cooling elements are directly in contact with the high-thermal-conductivity refractory material, heat can be rapidly and directly transmitted to a cooling system, the cooling efficiency is greatly improved, and a protective slag iron shell is easily formed on a hot surface of the hearth; the whole pouring structure is free of any brick joint, and penetration and corrosion of molten iron and alkali metal are avoided; high thermal conductivity ensures that the temperature field of the lining of the hearth is uniformly distributed and thermal stress is small, and the risk of ring crack of the traditional structure is fundamentally eliminated; if abnormal corrosion occurs in a local region, the on-line repair can be carried out by using the pressing-in technology, maintenance cost is low, and the service life of one generation of blast furnace is prolonged.

The application discloses a motor controller and a temperature measuring method thereof. The motor controller comprises a plurality of temperature sensors integrated in power chips, which are used to obtain junction temperatures of the power chips. The temperature measuring method comprises the following steps: obtaining the junction temperatures of the power chips; calculating temperatures of first to sixth reference points in a cooling water channel according to the junction temperatures and a preset thermal model; calculating inlet and outlet water temperatures based on the temperatures of the first to sixth reference points; and calculating temperatures of diode chips and capacitors according to preset first and second thermal models respectively. The application directly integrates the sensors to obtain real junction temperatures, reversely deduces local real water temperatures, and then estimates temperatures of each core node in a forward direction, so that model deviation caused by a single reference is eliminated systematically, and the temperature monitoring precision is improved.