5results about How to "Avoid thermal resistance" patented technology

The invention belongs to the technical field of heat-conducting silica gel, and relates to high-temperature-resistant heat-conducting silica gel as well as a preparation method and application thereof. The invention provides heat-conducting silica gel, which is prepared from the following raw materials in parts by mass: 10 to 20 parts of silicon rubber matrix, 100 parts of modified heat-conducting filler and 5 to 12 parts of auxiliaries, the preparation method of the modified heat-conducting filler comprises the following steps: adding glutaric anhydride and carnosic acid into a solvent to obtain a modifier, then adding the heat-conducting filler, heating to 60-80 DEG C under the protection of nitrogen, carrying out closed heat preservation for 5-10 hours, and cooling to room temperature to obtain the modified heat-conducting filler. According to the heat-conducting silica gel provided by the invention, the heat-conducting filler is subjected to surface treatment, so that gaps existing at the interface of particles and a polymer are reduced, the interface thermal resistance of the heat-conducting silica gel is reduced, and the high-temperature resistance of the heat-conducting silica gel is improved.

The invention belongs to the technical field of adhesive synthesis, and particularly relates to polyimide mixed glue containing graphite and graphene and a preparation process of the polyimide mixed glue. The mixed glue comprises the following components in parts by weight: 4-6 parts of modified graphite, 1-2 parts of modified graphene, 45-50 parts of N, N-dimethylformamide, 10-12 parts of a rigid diamine monomer, 8-10 parts of a flexible diamine monomer, 6-8 parts of a diamine monomer with a main chain containing an ester group and 18-20 parts of an aromatic anhydride monomer. According to the present invention, the aminosilane modified graphite and the bifunctional coupling agent modified graphene are adopted to enhance the dispersibility and the chemical binding force in the polyimide matrix so as to form the stable heat conduction path, and improve the thermal conductivity and the mechanical strength of the material, and the modified graphite and the modified graphene are uniformly dispersed in the aprotic polar solvent so as to avoid the agglomeration; and the stable performance under high temperature and long-term use is ensured.

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.