A high temperature resistant MEMS silicon piezoresistive pressure sensitive chip

Abstract

The invention discloses a high-temperature resistant MEMS silicon piezoresistive pressure sensitive chip, comprising a main body, the main body comprising a silicon wafer substrate, a sensitive resistor layer and an insulating layer are arranged on the silicon wafer substrate, a porous silicon structure is further formed on the upper part of the silicon wafer substrate, an aluminum film is arranged on the silicon wafer, a half-encapsulation part is arranged at the bottom of the main body, a damping release structure is arranged in the inner cavity of the half-encapsulation part, a receiving part connected to the encapsulation part is arranged at the bottom of the silicon wafer substrate, the receiving part is provided with a first adsorption layer and a second adsorption layer, the first adsorption layer is arranged on the encapsulation surface at the bottom of the silicon wafer substrate, the second adsorption layer is arranged on the half-encapsulation part, a first bonding mold and a second bonding mold are respectively arranged on the first adsorption layer and the second adsorption layer, the first bonding mold and the second bonding mold are provided with receiving holes with relatively staggered distribution, a heat conducting part and a breathable part are further arranged at the connection between the main body and the half-encapsulation part, the main body and the half-encapsulation part are connected by stacking blocks, so that the main body has good thermal conductivity, breathability and buffering performance.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure sensitive chips, and in particular to a high temperature resistant MEMS silicon piezoresistive pressure sensitive chip. Background Art

[0002] Piezoresistive pressure sensors are constructed using the piezoresistive effect of single-crystal silicon. Using single-crystal silicon wafers as elastic elements, a group of equal-value resistors are diffused in a specific direction of the single-crystal silicon using the process of integrated circuits on the single-crystal silicon diaphragm, and the resistors are connected into a bridge circuit, and the single-crystal silicon wafer is placed in the sensor cavity. When the pressure changes, the single-crystal silicon produces strain, causing the strain resistors directly diffused on it to produce changes proportional to the measured pressure, and then the corresponding voltage output signal is obtained by the bridge circuit. Piezoresistive sensors are ideal sensors for this purpose. For example, they are used to measure the airflow pressure distribution of helicopter wings, test the dynamic distortion of the engine air inlet, the pulsating pressure of the blades, and the flutter of the wings. In the measurement of the central pressure of aircraft jet engines, specially designed silicon pressure sensors are used, and their operating temperature reaches above 500°C. In the field of biomedicine, piezoresistive sensors are also ideal detection tools. Injection needle-type piezoresistive pressure sensors with diffused silicon membranes as thin as 10 microns and an outer diameter of only 0.5 mm and sensors that can measure cardiovascular, intracranial and intraocular pressure have been made. Piezoresistive sensors are also effectively used in the measurement of explosion pressure and shock waves, vacuum measurement, monitoring and controlling the performance of automobile engines, and measurement of weapons such as measuring the pressure in the gun barrel and emitting shock waves. In addition, piezoresistive sensors are widely used in oil well pressure measurement, drilling direction finding and detection of underground sealed cable fault points, flow and liquid level measurement. With the further development of microelectronics technology and computers, the application of piezoresistive sensors will develop rapidly. Common silicon piezoresistive pressure sensitive chips have poor thermal conductivity and internal fluidity, and the tightness of the connection between the chip and the package is poor. Summary of the invention

[0003] In order to solve the above problems, the present invention discloses a high temperature resistant MEMS silicon piezoresistive pressure sensitive chip, the chip comprises a main body, the main body comprises a silicon wafer substrate, a sensitive resistor layer and an insulating layer are arranged on the silicon wafer substrate, a porous silicon structure is also formed on the upper part of the silicon wafer substrate, an aluminum film is arranged on the silicon wafer, a half packaging part is arranged at the bottom of the main body, a damping buffer structure is arranged in the inner cavity of the half packaging part, a receiving part connected to the half packaging part is arranged at the bottom of the silicon wafer substrate, the receiving part is provided with a first adsorption layer and a second adsorption layer, the first adsorption layer is arranged on the packaging surface of the bottom of the silicon wafer substrate, the second adsorption layer is arranged on the half packaging part, and the first adsorption layer and the second adsorption layer are respectively provided with a first bonding layer. The main body and the semi-encapsulated part are connected to each other by a stacking block, and the stacking block has parallel surfaces in contact with the main body and the semi-encapsulated part. The main body and the semi-encapsulated part are provided with a heat-conducting part and a breathable part, and the heat-conducting part and the breathable part are arranged between the main body and the semi-encapsulated part. The heat-conducting part is designed in a grid type, and the breathable part is distributed inside the heat-conducting part, and has a breathable channel parallel to the heat-conducting part. The main body and the semi-encapsulated part are connected by a stacking block, and the stacking block has a parallel surface in contact with the main body and the semi-encapsulated part. The stacking block can use a material with a buffering property.

[0004] As an improvement of the present invention, the heat conducting part and the air permeable part, the heat conducting part contains a heat conducting cavity, a heat conducting film is arranged in the heat conducting cavity, the heat conducting film is arranged parallel to the air flow direction, and a safety distance is arranged between the heat conducting films, so that problems such as wear or adhesion between the films will not be caused due to long-term use. The air permeable parts are distributed at equal distances between the heat conducting parts. In order to improve the internal ventilation and circulation effect and be more beneficial to heat conduction, the air permeable parts can be provided with guide components.

[0005] As an improvement of the present invention, the damping buffer structure is installed in an internal position of the stacking block, and the damping buffer structure includes a damping release hole, and the damping release holes are evenly distributed inside the stacking block. The damping release holes can be set to equal distances and unequal distances, and the aperture sizes of the damping release holes can also be set to become smaller, larger or equal in sequence to adjust different buffering effects.

[0006] As an improvement of the present invention, the first laminating mold and the second laminating mold are provided with a wear-resistant layer, and the wear-resistant layer is provided with uniform wear-resistant particles.

[0007] As an improvement of the present invention, the wear-resistant layer is a gradient wear-resistant coating containing nanoparticles.

[0008] As an improvement of the present invention, the wear-resistant particles are evenly distributed on the wear-resistant layer, an adhesive layer is provided on the wear-resistant layer, the wear-resistant particles are provided on the adhesive layer, and the area of ​​the adhesive layer is the same as that of the wear-resistant particles.

[0009] As an improvement of the present invention, the insulating layer is a silicon dioxide structure.

[0010] As an improvement of the present invention, a sealing portion is provided at the connection between the main body and the semi-encapsulated portion.

[0011] As an improvement of the present invention, the accommodating holes are arranged opposite to each other in pairs, a connecting part is arranged between the two accommodating holes, a flow part is connected in the middle of the connecting part, the other end of the flow part is connected to another connecting part, and the other connecting part is connected to other two accommodating holes, and the connection between the accommodating holes is arranged on the first fitting mold or the second fitting mold. Such a design can make the connecting part and the flow part connect the accommodating holes to form a diffuse flow channel, thereby increasing the closeness between the main body and the semi-encapsulated body.

[0012] The beneficial effects of the present invention are as follows: the present invention provides a high-temperature resistant MEMS silicon piezoresistive pressure sensitive chip, by setting a connection structure between a main body and a semi-encapsulated part, the first bonding mold and the second bonding mold are provided with relatively staggered accommodating holes, which facilitates the discharge of bubbles from the contact surface between the first bonding mold and the second bonding mold, and the intricate design makes the area for bubble discharge larger, and a heat-conducting part and a breathable part are also installed at the connection between the main body and the semi-encapsulated part, so that the main body has good thermal conductivity and internal air permeability, and the designed accommodating holes can increase the closeness between the main body and the semi-encapsulated body. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The schematic diagram of the chip structure of the present invention is shown in FIG.

[0014] Figure 2 Schematic diagram of the receiving hole structure of the present invention Figure 1 .

[0015] Figure 3 Schematic diagram of the receiving hole structure of the present invention Figure 2 .

[0016] Figure 4 It is a schematic diagram of the bonding mold structure described in the present invention.

[0017] Figure 5 It is a schematic diagram of the structure of the heat conducting part and the air permeable part of the present invention.

[0018] List of figure marks: main body 1, silicon wafer substrate 2, semi-encapsulation part 3, damping buffer structure 4, accommodating part 5, first adsorption layer 6, second adsorption layer 7, first bonding mold 8, second bonding mold 9, accommodating hole 10, heat conducting part 11, breathable part 12, stack 13, heat conducting film 14, damping release hole 15, wear-resistant layer 16, wear-resistant particles 17, connecting part 18, circulation part 19. DETAILED DESCRIPTION

[0019] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0020] Embodiment: The present invention discloses a high temperature resistant MEMS silicon piezoresistive pressure sensitive chip, the chip comprising a main body 1, the main body 1 comprising a silicon wafer substrate 2, a sensitive resistor layer and an insulating layer are arranged on the silicon wafer substrate 2, a porous silicon structure is also formed on the upper part of the silicon wafer substrate 2, an aluminum film is arranged on the silicon wafer, a half encapsulation part 3 is arranged at the bottom of the main body 1, a damping buffer structure 4 is arranged in the inner cavity of the half encapsulation part 3, a receiving part 5 connected to the half encapsulation part 3 is arranged at the bottom of the silicon wafer substrate 2, the receiving part 5 is provided with a first adsorption layer 6 and a second adsorption layer 7, the first adsorption layer 6 is installed on the encapsulation surface at the bottom of the silicon wafer substrate 2, the second adsorption layer 7 is installed on the half encapsulation part 3, the first adsorption layer 6 and the second adsorption layer 7 are respectively provided with a first bonding mold 8 and a second bonding mold 9, The first laminating mold 8 and the second laminating mold 9 are provided with accommodating holes 10 which are relatively staggered in position. The setting of the accommodating holes 10 facilitates the discharge of bubbles from the contact surface of the first laminating mold 8 and the second laminating mold 9. The intricate design makes the bubble discharge area larger and the discharge efficiency higher. The connection between the main body 1 and the semi-encapsulation part 3 is also provided with a heat-conducting part 11 and a breathable part 12. The heat-conducting part 11 and the breathable part 12 are arranged at a position between the main body 1 and the semi-encapsulation part 3. The heat-conducting part 11 is designed in a grid type. The breathable part 12 is distributed inside the heat-conducting part 11 and has a breathable channel distributed parallel to the heat-conducting part 11. The main body 1 and the semi-encapsulation part 3 are connected by a stacking block 13. The stacking block 13 has a parallel surface in contact with the main body 1 and the semi-encapsulation part 3. The stacking block 13 can use a material with buffering properties.

[0021] Furthermore, the heat conducting part 11 and the air permeable part 12, the heat conducting part 11 contains a heat conducting cavity, a heat conducting film 14 is arranged in the heat conducting cavity, the heat conducting film 14 is arranged parallel to the air flow direction, and a safety distance is arranged between the heat conducting films 14, so that problems such as wear or adhesion between the films will not occur due to long-term use. The air permeable parts 12 are equidistantly distributed between the heat conducting parts 11. In order to improve the air permeability effect, the air permeable parts 12 can be provided with guide components.

[0022] Furthermore, the damping buffer structure 4 is installed at an internal position of the stack block 13, and the damping buffer structure 4 includes a damping release hole 15, and the damping release holes 15 are evenly distributed inside the stack block 13. The damping release holes 15 can be set to equal distances and unequal distances, and the aperture sizes of the damping release holes 15 can also be set to become smaller, larger or equal in sequence to adjust different buffering effects.

[0023] Furthermore, a wear-resistant layer 16 is installed on the first laminating mold 8 and the second laminating mold 9 , and the wear-resistant layer 16 is provided with uniform wear-resistant particles 17 .

[0024] Furthermore, the wear-resistant layer 16 is a gradient wear-resistant coating containing nanoparticles.

[0025] Furthermore, the wear-resistant particles 17 are evenly distributed on the wear-resistant layer 16 , an adhesive layer is disposed on the wear-resistant layer 16 , and the wear-resistant particles 17 are disposed on the adhesive layer, and the area of ​​the adhesive layer is the same as that of the wear-resistant particles 17 .

[0026] Furthermore, the insulating layer is a silicon dioxide structure.

[0027] Furthermore, a sealing portion is provided at the connection between the main body 1 and the semi-encapsulated portion 3 .

[0028] Furthermore, the accommodating holes 10 are arranged opposite to each other in pairs, and a connecting portion 18 is arranged between the two accommodating holes 10. A circulation portion 19 is connected in the middle of the connecting portion 18, and the other end of the circulation portion 19 is connected to another connecting portion 18, and the other connecting portion 18 is connected to another two accommodating holes 10. The connection between the accommodating holes 10 is arranged on the first bonding mold 8 or the second bonding mold 9, and the accommodating holes 10, the connecting portion 18 and the circulation portion 19 are the same.

[0029] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Finally, it should be noted that the embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high temperature resistant MEMS silicon piezoresistive pressure sensitive chip, characterized in that The chip comprises a main body (1), the main body (1) comprises a silicon wafer substrate (2), a sensitive resistor layer and an insulating layer are arranged on the silicon wafer substrate (2), a porous silicon structure is formed on the upper part of the silicon wafer substrate (2), an aluminum film is arranged on the upper part of the silicon wafer substrate (2), a half encapsulation part (3) is arranged at the bottom of the main body (1), a damping buffer structure (4) is arranged in the inner cavity of the half encapsulation part (3), a receiving part (5) connected to the half encapsulation part (3) is arranged at the bottom of the silicon wafer substrate (2), the receiving part (5) is provided with a first adsorption layer (6) and a second adsorption layer (7), the first adsorption layer (6) is arranged on the encapsulation surface of the bottom of the silicon wafer substrate (2), and the second adsorption layer (7) is arranged on the half encapsulation part (3), The first adsorption layer (6) and the second adsorption layer (7) are respectively provided with a first laminating mold (8) and a second laminating mold (9); the first laminating mold (8) and the second laminating mold (9) are provided with accommodating holes (10) which are relatively staggered in position; a heat conducting part (11) and a breathable part (12) are also provided at the connection between the main body (1) and the semi-encapsulated part (3); the main body (1) and the semi-encapsulated part (3) are connected via a stacking block (13); a sealing part is provided at the connection between the main body (1) and the semi-encapsulated part (3); the damping buffer structure (4) is installed at an internal position of the stacking block (13); the damping buffer structure (4) comprises a damping release hole (15); and the damping release holes (15) are evenly distributed inside the stacking block (13).

2. The high temperature resistant MEMS silicon piezoresistive pressure sensitive chip according to claim 1 is characterized in that The heat-conducting portion (11) comprises a heat-conducting cavity, a heat-conducting film (14) is arranged in the heat-conducting cavity, the heat-conducting film (14) is arranged parallel to the air flow direction, and the air-permeable portions (12) are distributed between the heat-conducting portions (11) at equal distances.

3. The high temperature resistant MEMS silicon piezoresistive pressure sensitive chip according to claim 1 is characterized in that The first laminating mold (8) and the second laminating mold (9) are provided with a wear-resistant layer (16), and the wear-resistant layer (16) is provided with uniform wear-resistant particles (17).

4. The high temperature resistant MEMS silicon piezoresistive pressure sensitive chip according to claim 3 is characterized in that The wear-resistant layer (16) is a gradient wear-resistant coating containing nanoparticles.

5. The high temperature resistant MEMS silicon piezoresistive pressure sensitive chip according to claim 3 is characterized in that The wear-resistant particles (17) are evenly distributed on the wear-resistant layer (16), a bonding layer is provided on the wear-resistant layer (16), and the wear-resistant particles (17) are provided on the bonding layer.

6. The high temperature resistant MEMS silicon piezoresistive pressure sensitive chip according to claim 1 is characterized in that , the insulating layer is a silicon dioxide structure.

7. The high temperature resistant MEMS silicon piezoresistive pressure sensitive chip according to claim 1, characterized in that: The accommodating holes (10) are arranged opposite to each other in pairs, a connecting portion (18) is arranged between the two accommodating holes (10), a circulation portion (19) is connected in the middle of the connecting portion (18), the other end of the circulation portion (19) is connected to another connecting portion (18), and the other connecting portion (18) is connected to another two accommodating holes (10), and the connection between the accommodating holes (10) is arranged on the first bonding mold (8) or the second bonding mold (9).

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