36results about How to "Consistent coefficient of thermal expansion" patented technology

The invention discloses a power thick-film resistor which comprises a resistor substrate provided with a printed internal electrode and a resistor both on one surface as well as a printed back electrode on the other surface, wherein a heat-conducting plate is arranged on the surface of the back electrode of the resistor substrate in a matching manner, and is a porcelain substrate of which the inner surface and the outer surface are fixedly coated with an inner heat-conducting fin and an outer heat-conducting fin respectively; the surface of the inner heat-conducting fin is plated with a nickel layer; the nickel layer is oppositely welded and fixed with the back electrode on the resistor substrate in a matching manner. The porcelain substrate of which the inner surface and the outer surface are coated with the inner heat-conducting fin and the outer heat-conducting fin in a welding manner is welded on the surface of the back electrode of the resistor substrate to serve as the heat-conducting plate, and the heat-conducting fins on the two surfaces cancel out each other due to temperature distortion so as to enable the thermal expansion coefficient of the heat-conducting plate to be basically the same as that of the resistor substrate, so that the problem that the resistor substrate cracks due to the inconsistent thermal expansion coefficient during the use of the resistor substrate in a large size resistor is solved; the power thick-film resistor has the advantages that under the condition of the same size, the resistor is larger in power compared with a conventional resistor, the stable performance is realized, and the temperature distortion cannot be caused.

The invention provides an electronic chip packaging method in order to eliminate the cost disadvantage of the prior art. With the electronic chip packaging method adopted, the production cost of a whole process is effectively reduced. The electronic chip packaging method is characterized by comprising the following steps of: a, obtaining a finished product carrier, and forming a groove in the finished product carrier; b, mounting a chip on a substrate; and c, mounting the substrate with the chip into the groove.

The invention discloses a minitype dynamic infiltration water pressure sensor which comprises a shell, a cup-shaped base, a stainless steel rear cover, a water permeable stone layer and a signal modulation amplification module. A step surface is arranged on the inner wall of the cup-shaped base, and the water permeable stone layer is mounted on the step surface of the cup-shaped base. The cup-shaped base is embedded into a front cavity and is mounted on the step circular ring surface of the shell. The stainless steel rear cover is mounted at the end, placed on a rear cavity, of the shell, and a silicon nitride thin film covers the inner surface of the cup-shaped base. A pressure sensitive assembly is arranged on the surface, opposite to the water permeable stone layer, of the cup-shaped base, a first leading wire is connected between the pressure sensitive assembly and one end of the signal modulation amplification module in a bridging mode, and a signal cable is embedded into a through hole of the stainless steel rear cover and is connected to the other end of the signal modulation amplification module through a second leading wire. By means of the minitype dynamic infiltration water pressure sensor, the dynamic frequency response and the measurement accuracy of the pressure sensor are improved, the measuring range is greatly increased, sensing precision and sensitivity are also improved, and the degree of linearity of signals of the pressure sensor is improved.