Patent Application
20210082785
The present invention relates to the technical field of semiconductor devices, and more particularly to a semiconductor power device and its manufacturing method.
As science and technology advance, new-generation semiconductor power devices have increasingly higher density and better performance, and the third-generation semiconductor power device represented by the gallium nitride (GaN) power device has shown its excellent applications of high power, high voltage and high density.
Research results indicate that the performance of semiconductor power devices is much higher than the physical limit performance of traditional power devices. The main reason is that the semiconductor power device generates and accumulate massive heat to increase the temperature of the device drastically while outputting large current, and the gallium nitride (GaN) and silicon carbide (SiC) power devices usually adopt conventional packaging technologies and come with a plastic package with a heat conductivity higher than those of the traditional power devices and give rise to a low thermal conductivity and a poor heat dissipation to limit the performance of the gallium nitride and silicon carbide power devices. As a result, the performance and reliability of the semiconductor power devices are reduced significantly, and the use of such devices is limited.
In view of the drawbacks of the prior art, the present invention provides a semiconductor power device and its manufacturing method with the features of simple structure, reasonable design, good heat dissipating effect, and excellent performance to overcome the drawbacks of the prior art.
To achieve the aforementioned and other objectives, the present invention discloses a semiconductor power device, comprising a substrate, a power chip, and a capping layer, and the substrate has a patterned unit, and the thickness of the substrate is matched with the configuration of the power chip, and the height of the power chip is smaller than the thickness of the substrate, and the power chip is installed at a position corresponding to the patterned unit, and the capping layer is covered onto a side of the substrate having the patterned unit, and the power chip is covered by the capping layer and installed to the substrate.
Wherein, the substrate is made of a diamond material, and the capping layer is a diamond capping layer.
Wherein, the diamond material is a polycrystalline diamond material, a monocrystalline diamond material, a quasi-polycrystalline diamond material or any combination of the above.
Wherein, the substrate has an area of 0.1 mm2˜90000 mm2, a thickness of 0.1 mm-80 mm, and a size matched with the configuration of the power device.
Wherein, the substrate is in a polygonal shape, a circular shape, or a triangular shape.
Wherein, the capping layer has a thickness of 0.1 mm-10 mm, and the thickness of the capping layer is matched with the configuration of the power chip.
Wherein, the power chip has a pin, and the pin comprises a source S, a drain D, and a gate G.
To achieve the aforementioned and other objectives, the present invention also discloses a manufacturing method of a semiconductor power device, and the manufacturing method comprises the following steps (Steps 1˜5).
Step 1: Prepare a substrate.
Step 2: Install a patterned unit on the substrate.
Step 3: Install a power chip, and engage a plurality of power chips into a plurality of chip units respectively.
Step 4: Install a pin protective film to a pin of the power chip.
Step 5: Install a capping layer, deposit a diamond material according to the height of the power chip to form a diamond capping layer to produce the power device.
In Step 1, a CVD method is used or a diamond powder is pressed to form a diamond substrate.
In Step 2, a semiconductor lithography, a physical compression or a laser manufacturing method is used to install a patterned unit on a side of the substrate and a plurality of chip units on the patterned unit.
In Step 3, a small amount of silver paste or high temperature solder paste is used to fix the power chip.
In Step 4, a semiconductor photoresist glue is used to install the protective film to the pin for protection.
In Step 5, a CVD process is used to deposit the diamond material on a side of the substrate having the patterned unit, so as to form the capping layer.
After the Step 5, the substrate is cut according to the distribution of the power chip by a laser, mechanical or etching method, and then the pin protective film is removed after the substrate is cut, so as to obtain an independently formed power device.
The present invention has the following advantageous effects:
1. The semiconductor power device of the present invention has a diamond material fully covered onto the power chip to overcome the heat accumulation problem of the silicon carbide and gallium nitride power device, and a diamond material with high thermal conductivity is used to fully cover and package the power device to improve the thermal conductive channels and dissipate the heat generated by the operation of the device to the outside quickly, so that the device is always situated at a relatively low operating temperature to achieve the best working performance of the device, and the present invention skillfully uses the diamond material with a very high thermal conductivity, and its heat dissipation performance is much better than other materials such as metals. The thermal conductivity of diamond is up to 2000 W/m·K (much higher than the thermal conductivity of copper which is equal to 380 W/m·K). The invention breaks through the traditional plastic packaging and the limitation of the traditional devices that cannot be used in an application with a temperature above 300° C. In addition, the semiconductor power device of the invention has the features of simple structure, reasonable design, good heat dissipation, and excellent performance.
2. The manufacturing method of the semiconductor power device of the present invention has the features of simple process and easy operation and meets the industrial manufacturing requirements, and the semiconductor power device manufactured by this method has good performance.
Brief Description of Numerals Used in the Drawings: 1: Substrate; 2; Patterned unit; 3: Power chip; 4: Pin; 5: Chip unit; 6: Capping layer.
The objectives, technical characteristics and effects of the present invention will become apparent with the detailed description of preferred embodiments accompanied with the illustration of related drawings. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive.
With reference to
The substrate 1 is made of a diamond material, and the thermal conductivity of diamond is up to 2000 W/m·K (much higher than the thermal conductivity of copper which is equal to 380 W/m·K). Therefore, the diamond material plays the role of a high-efficiency thermal conductive channel to further improve the heat dissipation performance of the present invention.
The diamond material is a polycrystalline diamond material, a monocrystalline diamond material, a quasi-polycrystalline diamond material, or any combination of the above. The substrate has an area of 0.1 mm2˜90000 mm2, a thickness of 0.1 mm-80 mm, and a size matched with the configuration of the power device, and the substrate 1 can be in a polygonal, circular or triangular shape which can be changed flexibly according to actual requirements to facilitate the application.
The capping layer 6 is a diamond capping layer 6 with a thickness of 0.1 mm-10 mm, and the thickness is matched with the configuration of the power chip. The structure is simple and the design is reasonable. The diamond capping layer 6 provides good thermal conduction and heat dissipation to ensure the heat dissipation and performance of the present invention.
The power chip 3 has a pin 4, and the pin 4 comprises a source S, a gate D and a gate G. The structure is simple and the design is reasonable. The power chip 3 can be connected to other components easily to facilitate the application.
The manufacturing method of the semiconductor power device comprises the following steps (S1 to S7).
Step 1: Prepare a substrate 1, wherein a CVD method or a diamond powder is pressed to form a diamond substrate 1.
Step 2: Install a patterned unit 2 on the substrate 1, wherein a semiconductor lithography, a physical compression, or a laser manufacturing method is used to install the patterned unit 2 on a side of substrate 1, and the patterned unit 2 has a plurality of chip units 5.
Step 3: Install a power chip 3, and engage a plurality of power chips 3 into a plurality of chip units 5 respectively, wherein a small amount of silver paste or high temperature solder paste process is used for curing;
Step 4: Install a protective film to a pin 4 of the power chip 3, wherein the protective film is installed to the pin 4 by using a semiconductor photoresist glue for protection.
Step 5: Install a capping layer 6, wherein a CVD process is used to deposit a diamond material on a side of the substrate 1 having the patterned unit 2, so as to form the capping layer 6.
Step 6: Cut the substrate 1, wherein the substrate 1 is cut according to the distribution of the power chips 3 by using a laser, mechanical or etching method.
Step 7: Remove the protective film, wherein the protective film of the pin 4 is removed, so that the diamond capping layer 6 deposited on the protective film falls off together with the protective film, and the pin 4 of the power chip 3 is exposed, and finally the power device is formed independently.
In summation, the manufacturing method of the present invention comprises the steps of preparing the diamond substrate 1, patternizing the substrate 1, laying the power chip 3, depositing a diamond capping layer, cutting and removing the film, etc. In
While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention as set forth in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910880306.3 | Sep 2019 | CN | national |
