Absolute pressure sensitive structure manufacturing method and absolute pressure sensitive structure

Abstract

The invention relates to the technical field of capacitive pressure sensors, and provides an absolute pressure sensitive structure manufacturing method and an absolute pressure sensitive structure, and the method comprises the steps: printing glass slurry on an upper substrate and a lower substrate based on screen printing; pre-sintering the upper substrate sheet and the lower substrate sheet; aligning and pre-fixing the upper substrate sheet, the pressure sensing film sheet and the lower substrate sheet; carrying out vacuum sintering on the pre-fixed upper substrate sheet, the pre-fixed pressure sensing diaphragm and the pre-fixed lower substrate sheet; and cutting up the bonded upper substrate sheet, the pressure sensing film sheet and the lower substrate sheet to form an absolute pressure sensitive structure bare chip. On the basis of a glass slurry bonding mode, by utilizing the printing accuracy of silk-screen printing and accurate control over the boundary of glass slurry, the structural strength and sealing degree of bonding are ensured, the stability and reliability of the structure are improved, a large number of metal materials do not need to be used, the implementation cost is reduced, the production efficiency is high, and the repeatability is high; and the production yield can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitive pressure sensors, and particularly to a method for manufacturing an absolute pressure sensitive structure and an absolute pressure sensitive structure. Background Art

[0002] An absolute pressure sensor measures the pressure of a measured medium by comparing it with the zero pressure in a vacuum chamber to measure the pressure change of the measured medium relative to absolute vacuum (zero pressure). Among them, a capacitive absolute pressure sensor measures pressure through the displacement change of a pressure-sensitive diaphragm under the action of pressure. The pressure-sensitive diaphragm deforms when the pressure changes, changing the distance between the two electrodes of the capacitor, and then changing the capacitance value to reflect the pressure change.

[0003] In the prior art, during the manufacturing and assembly process of the absolute pressure sensitive structure inside a capacitive absolute pressure sensor, bonding or eutectic soldering is mainly used for assembly. However, the bonding method has insufficient strength, resulting in structural stability problems, and the working temperature range is limited and cannot adapt to high-temperature working environments; the eutectic soldering method requires a large amount of metal materials, with a high manufacturing cost, and a high degree of human participation in the production process, high operating requirements, and problems of slow production efficiency and low yield. Summary of the Invention

[0004] The present invention provides a method for manufacturing an absolute pressure sensitive structure and an absolute pressure sensitive structure to solve the defects in the prior art that during the manufacturing process of the absolute pressure sensitive structure, there are problems of insufficient strength, structural stability, and manufacturing cost due to the use of a large amount of metal materials.

[0005] The present invention provides a method for manufacturing an absolute pressure sensitive structure, including: Printing glass paste on a first preset position of an upper substrate and a second preset position of a lower substrate based on screen printing; Performing pre-firing treatment on the upper substrate and the lower substrate to form a first glass paste layer on the glass paste on the upper substrate and a second glass paste layer on the glass paste on the lower substrate; Aligning and pre-fixing the upper substrate, the pressure-sensitive diaphragm, and the lower substrate; Performing vacuum sintering on the pre-fixed upper substrate, the pressure-sensitive diaphragm, and the lower substrate, so that the first glass paste layer forms a first glass paste bonding layer and the second glass paste layer forms a second glass paste bonding layer. The first glass paste bonding layer is bonded to the upper substrate and the pressure-sensitive diaphragm respectively to form a detection chamber, and the second glass paste bonding layer is bonded to the lower substrate and the pressure-sensitive diaphragm respectively to form a vacuum chamber; The bonded upper base sheet, the pressure-sensitive film, and the lower base sheet are scribed to form a bare die of the absolute pressure sensitive structure.

[0006] According to a method for manufacturing an absolute pressure sensitive structure provided by the present invention, before printing glass paste on the first preset position of the upper base sheet and the second preset position of the lower base sheet based on screen printing, it further includes: Processing the upper base sheet to form a first boss, and processing the lower base sheet to form a second boss; Wherein, the first boss is used to abut against the pressure-sensitive film to limit the thickness of the first glass paste bonding layer, and the second boss is used to abut against the pressure-sensitive film to limit the thickness of the second glass paste bonding layer.

[0007] According to a method for manufacturing an absolute pressure sensitive structure provided by the present invention, before printing glass paste on the first preset position of the upper base sheet and the second preset position of the lower base sheet based on screen printing, it further includes: Processing the upper base sheet to form a first upper electrode and a first pad connected to the first upper electrode, and processing a detection through hole on the upper base sheet based on ultrasonic drilling or wet etching; Processing the pressure-sensitive film to form a second upper electrode, a first lower electrode, and a second pad both connected to the second upper electrode and the first lower electrode; Processing the lower base sheet to form a second lower electrode and a third pad connected to the second lower electrode; Wherein, the first upper electrode, the second upper electrode, the first lower electrode, and the second lower electrode are defined in pattern based on a photolithography process or a mask process and are formed by magnetron sputtering or electron beam evaporation.

[0008] According to a method for manufacturing an absolute pressure sensitive structure provided by the present invention, printing glass paste on the first preset position of the upper base sheet and the second preset position of the lower base sheet based on screen printing includes: Making a first alignment mark portion on the screen printing plate; Making a second alignment mark portion on the upper base sheet and making a third alignment mark portion on the lower base sheet; Using a CCD camera for alignment, aligning the first alignment mark portion with the second alignment mark portion, printing the paste unit on the screen printing plate at the first preset position of the upper base sheet, and standing for 3 to 5 minutes for the paste to level; Using a CCD camera for alignment, aligning the first alignment mark portion with the third alignment mark portion, printing the paste unit on the screen printing plate at the second preset position of the lower base sheet, and standing for 3 to 5 minutes for the paste to level.

[0009] A method for manufacturing an absolute pressure sensitive structure provided by the present invention, the pre-firing treatment of the upper base sheet and the lower base sheet includes: Place the upper base sheet and the lower base sheet into a high-temperature oven; Control the high-temperature oven. Starting from room temperature, set a heating rate of 5 degrees Celsius per minute, heat up to 150 degrees Celsius and keep warm for 15 to 30 minutes to discharge the organic solvents in the glass paste, heat up to 200 degrees Celsius and keep warm for 30 minutes to discharge the organic binders in the glass paste, heat up to 250 degrees Celsius and keep warm for 15 to 30 minutes to activate the thixotropic agent in the glass paste, heat up to 300 degrees Celsius and keep warm for 15 to 30 minutes to crystallize the glass paste, heat up to 350 degrees Celsius and keep warm for 15 to 30 minutes to form a first glass paste layer on the glass paste of the upper base sheet and a second glass paste layer on the glass paste of the lower base sheet; End the heat preservation. Wait for the high-temperature oven to cool to room temperature and take out the upper base sheet and the lower base sheet.

[0010] A method for manufacturing an absolute pressure sensitive structure provided by the present invention, a fourth alignment mark portion is provided on the pressure-sensitive diaphragm, and the alignment and pre-fixation of the upper base sheet, the pressure-sensitive diaphragm and the lower base sheet include: Using a wafer-level alignment device, adjust the relative positions of the pressure-sensitive diaphragm and the lower base sheet to align the third alignment mark portion with the fourth alignment mark portion. Add UV glue between the pressure-sensitive diaphragm and the lower base sheet, drive the pressure-sensitive diaphragm close to the lower base sheet to squeeze the UV glue, and perform irradiation curing treatment on the UV glue to pre-fix the pressure-sensitive diaphragm and the lower base sheet to form a two-layer negative film structure; Using a wafer-level alignment device, adjust the relative positions of the upper base sheet and the two-layer negative film structure to align the second alignment mark portion with the fourth alignment mark portion. Add UV glue between the pressure-sensitive diaphragm and the upper base sheet, drive the upper base sheet close to the pressure-sensitive diaphragm to squeeze the UV glue, and perform irradiation curing treatment on the UV glue to pre-fix the upper base sheet and the pressure-sensitive diaphragm to form a three-layer negative film structure.

[0011] A method for manufacturing an absolute pressure sensitive structure provided by the present invention, the vacuum sintering of the pre-fixed upper base sheet, the pressure-sensitive diaphragm and the lower base sheet includes: Place the three-layer negative film structure into a variable-load muffle furnace; Control the variable-load muffle furnace to apply a load force of 5 kg to 10 kg by the fixture to fix the three-layer negative film structure. Set a heating rate of 5 °C per minute, heat up to 520 °C and keep warm for 15 to 30 minutes. During the heat preservation, apply a load force of 150 kg to 250 kg by the fixture and the vacuum degree is 1E-3 Pa, so that the first glass paste layer forms the first glass paste bonding layer and the second glass paste layer forms the second glass paste bonding layer; End the heat preservation. Wait for the variable-load muffle furnace to cool down to 250 °C to 260 °C, remove the load force of the fixture. Wait for the temperature to drop to 150 °C and open the furnace door of the variable-load muffle furnace. Wait for the variable-load muffle furnace to cool down to room temperature and take out the three-layer negative film structure.

[0012] According to a method for manufacturing an absolute pressure sensitive structure provided by the present invention, the absolute pressure sensitive structure die includes an upper substrate, the first glass paste bonding layer, a pressure sensitive film, the second glass paste bonding layer and a lower substrate. After dicing the bonded upper substrate sheet, the pressure sensitive film sheet and the lower substrate sheet to form an absolute pressure sensitive structure die, it further includes: Fix the processing chip on the upper substrate; Based on wire bonding, connect the processing chip with the first pad of the upper substrate, the second pad of the pressure sensitive film and the third pad of the lower substrate.

[0013] According to a method for manufacturing an absolute pressure sensitive structure provided by the present invention, the upper substrate sheet, the pressure sensitive film sheet and the lower substrate sheet are all quartz wafers, and the thermal expansion coefficients of the first glass paste bonding layer and the second glass paste bonding layer match the thermal expansion coefficient of the quartz wafer.

[0014] The present invention also provides an absolute pressure sensitive structure, including an upper substrate, a first glass paste bonding layer, a pressure sensitive film, a second glass paste bonding layer and a lower substrate. The upper substrate is connected to the pressure sensitive film through the first glass paste bonding layer to form a detection chamber, and the lower substrate is connected to the pressure sensitive film through the second glass paste bonding layer to form a vacuum chamber. The upper substrate is provided with a detection through hole and a first upper electrode communicating with the detection chamber. The pressure sensitive film is provided with a second upper electrode and a first lower electrode. The lower substrate is provided with a second lower electrode. The first upper electrode and the second upper electrode are located in the detection chamber, and the first lower electrode and the second lower electrode are located in the vacuum chamber; Wherein, the absolute pressure sensitive structure is obtained by the above-mentioned method for manufacturing an absolute pressure sensitive structure.

[0015] The method for manufacturing an absolute pressure sensitive structure and the absolute pressure sensitive structure provided by the present invention have at least the following beneficial effects: By means of screen printing, glass paste is printed on the upper substrate and the lower substrate. Utilizing the accuracy of screen printing, it is ensured that the glass paste can be accurately printed at the required positions, and screen printing can control the boundary of the glass paste to prevent the fluidity of the glass paste from causing size fluctuations of the glass paste. Through pre-burning treatment, the glass paste on the upper substrate is cured to form a first glass paste layer, and the glass paste on the lower substrate is cured to form a second glass paste layer to pre-shape the glass paste and avoid the influence of size changes of the glass paste on the reliability and sealing degree of subsequent bonding. The upper substrate, the pressure-sensitive diaphragm, and the lower substrate are aligned and pre-fixed to facilitate subsequent bonding connection. The pre-fixed upper substrate, pressure-sensitive diaphragm, and lower substrate are subjected to vacuum sintering. The first glass paste layer forms a first glass paste bonding layer to bond the upper substrate and the pressure-sensitive diaphragm to form a detection chamber, and the second glass paste layer forms a second glass paste bonding layer to bond the lower substrate and the pressure-sensitive diaphragm to form a vacuum chamber. The vacuum-sintered upper substrate, pressure-sensitive diaphragm, and lower substrate are subjected to dicing treatment to form a plurality of absolute pressure sensitive structure chips. In this way, based on the method of glass paste bonding, by using the printing accuracy of screen printing and the accurate control of the boundary of the glass paste, the sizes and shapes of the formed first glass paste bonding layer and second glass paste bonding layer can be accurately controlled, ensuring the structural strength and sealing degree of the bonding, which is beneficial to improving the stability and reliability of the structure. At the same time, the method of glass paste bonding does not require the use of a large amount of metal materials. Screen printing of glass paste can accurately control the amount of glass paste used, which is beneficial to reducing the implementation cost, and has high production efficiency and high repeatability, which is beneficial to ensuring the yield rate of production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of one embodiment of the method for manufacturing an absolute pressure sensitive structure provided by the present invention.

[0018] Figure 2 It is a schematic structural diagram of a screen printing plate in one embodiment of the method for manufacturing an absolute pressure sensitive structure provided by the present invention.

[0019] Figure 3This is a schematic diagram of the structure after the second glass paste layer is screen-printed on the lower substrate in one embodiment of a method for manufacturing an absolute pressure sensitive structure provided by the present invention.

[0020] Figure 4 It is a schematic diagram of the structure after the first glass paste layer is screen-printed on the upper substrate in one embodiment of a method for manufacturing an absolute pressure sensitive structure provided by the present invention.

[0021] Figure 5 The present invention provides a method for manufacturing an absolute pressure sensitive structure provided by the present invention, in which a lower substrate and a pressure-sensitive diaphragm are pre-fixed in one embodiment.

[0022] Figure 6 It is a structural schematic diagram of a three-layer bottom film structure in which an upper bottom film, a pressure-sensitive diaphragm and a lower bottom film are pre-fixed in one embodiment of a method for manufacturing an absolute pressure sensitive structure provided by the present invention.

[0023] Figure 7 It is a structural schematic diagram of one embodiment of an absolute pressure sensing structure provided by the present invention.

[0024] Figure 8 It is a schematic diagram of the cross-sectional structure of an upper substrate in one embodiment of an absolute pressure sensitive structure provided by the present invention.

[0025] Figure 9 It is a schematic structural diagram of the first upper electrode side of the upper substrate in one embodiment of an absolute pressure sensitive structure provided by the present invention.

[0026] Figure 10 It is a schematic structural diagram of an upper substrate facing away from a first upper electrode in one embodiment of an absolute pressure sensitive structure provided by the present invention.

[0027] Figure 11 It is a schematic diagram of the cross-sectional structure of a pressure-sensitive film in one embodiment of an absolute pressure-sensitive structure provided by the present invention.

[0028] Figure 12 It is a schematic structural diagram of the second upper electrode side of the pressure-sensitive film in one embodiment of an absolute pressure-sensitive structure provided by the present invention.

[0029] Figure 13 It is a schematic diagram of the cross-sectional structure of a lower substrate in one embodiment of an absolute pressure sensitive structure provided by the present invention.

[0030] Figure 14 It is a schematic structural diagram of the second lower electrode side of the lower substrate in one embodiment of an absolute pressure sensitive structure provided by the present invention.

[0031] Reference numerals: 100: Upper base sheet; 101: Upper substrate; 110: First upper electrode; 120: Detection through-hole; 130: First boss; 140: First pad; 200: Pressure-sensitive diaphragm; 201: Pressure-sensitive film; 210: Second upper electrode; 220: First lower electrode; 230: Second pad; 300: Lower base sheet; 301: Lower substrate; 310: Second lower electrode; 320: Second boss; 330: Third pad; 400: First glass paste layer; 410: First glass paste bonding layer; 500: Second glass paste layer; 510: Second glass paste bonding layer; 600: Processing chip; 710: First alignment mark portion; 720: Paste unit. Detailed implementation manner

[0032] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0033] The following combines Figures 1 - 6 Describe a method for manufacturing an absolute pressure sensitive structure of the present invention, including: Based on screen printing, print glass paste on the first preset position of the upper base sheet 100 and the second preset position of the lower base sheet 300; Perform pre-burning treatment on the upper base sheet 100 and the lower base sheet 300 to make the glass paste on the upper base sheet 100 form the first glass paste layer 400 and the glass paste on the lower base sheet 300 form the second glass paste layer 500; Align and pre-fix the upper base sheet 100, the pressure-sensitive diaphragm 200 and the lower base sheet 300; Perform vacuum sintering on the pre-fixed upper base sheet 100, the pressure-sensitive diaphragm 200 and the lower base sheet 300, so that the first glass paste layer 400 forms the first glass paste bonding layer 410 and the second glass paste layer 500 forms the second glass paste bonding layer 510. The first glass paste bonding layer 410 is bonded to the upper base sheet 100 and the pressure-sensitive diaphragm 200 respectively to form a detection chamber, and the second glass paste bonding layer 510 is bonded to the lower base sheet 300 and the pressure-sensitive diaphragm 200 respectively to form a vacuum chamber; Perform dicing treatment on the bonded upper base sheet 100, the pressure-sensitive diaphragm 200 and the lower base sheet 300 to form a bare chip of the absolute pressure sensitive structure.

[0034] By means of screen printing, glass paste is printed on the upper substrate 100 and the lower substrate 300. Utilizing the precision of screen printing, it is ensured that the glass paste can be accurately printed at the desired positions, and screen printing can control the boundary of the glass paste to prevent the size of the glass paste from fluctuating due to its fluidity. Through pre-burning treatment, the glass paste on the upper substrate 100 is cured to form the first glass paste layer 400, and the glass paste on the lower substrate 300 is cured to form the second glass paste layer 500 to pre-shape the glass paste and avoid the influence of the size change of the glass paste on the reliability and sealing degree of subsequent bonding. The upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 are aligned and pre-fixed with each other to facilitate subsequent bonding connection. The pre-fixed upper substrate 100, pressure-sensitive diaphragm 200, and lower substrate 300 are subjected to vacuum sintering. The first glass paste layer 400 forms the first glass paste bonding layer 410 to bond the upper substrate 100 and the pressure-sensitive diaphragm 200 to form a detection chamber, and the second glass paste layer 500 forms the second glass paste bonding layer 510 to bond the lower substrate 300 and the pressure-sensitive diaphragm 200 to form a vacuum chamber. The upper substrate 100, pressure-sensitive diaphragm 200, and lower substrate 300 after vacuum sintering are subjected to dicing treatment to form a plurality of absolute pressure sensitive structure dies.

[0035] Thus, based on the method of glass paste bonding, by utilizing the printing precision of screen printing and the accurate control of the boundary of the glass paste, the sizes and shapes of the formed first glass paste bonding layer 410 and second glass paste bonding layer 510 can be accurately controlled, ensuring the bonding structural strength and sealing degree, which is beneficial to improving the stability and reliability of the structure. At the same time, the method of glass paste bonding does not require the use of a large amount of metal materials. Screen printing the glass paste can accurately control the amount of the glass paste, which is beneficial to reducing the implementation cost, and has high production efficiency and high repeatability, which is beneficial to ensuring the yield rate of production.

[0036] It can be understood that the upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 include multiple parts corresponding to the absolute pressure sensitive structure. After the upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 are subjected to dicing treatment, a plurality of separate absolute pressure sensitive structure dies are formed. Correspondingly, the glass paste printed by screen printing is at multiple positions on the upper substrate 100 and the lower substrate 300 to form a plurality of first glass paste bonding layers 410 and second glass paste bonding layers 510 subsequently. After the dicing treatment, each absolute pressure sensitive structure die includes the first glass paste bonding layer 410 and the second glass paste bonding layer 510.

[0037] It should be noted that, in order to prevent the glass paste from flowing and deforming during the processing due to its fluidity, which may affect the shape reliability of subsequent bonding, in the present invention, through pre-sintering treatment, the glass paste is pre-shaped to form a first glass paste layer 400 and a second glass paste layer 500. At this time, after the pre-sintering treatment of the glass paste, it is shaped and will not flow and deform during subsequent processing and movement. At the same time, the temperature of the pre-sintering treatment has not reached the bonding temperature yet. During subsequent vacuum sintering, the first glass paste layer 400 and the second glass paste layer 500 bond the upper substrate sheet 100 to the pressure-sensitive membrane 200 and the lower substrate sheet 300 to the pressure-sensitive membrane 200 respectively. In this way, the shape reliability of the first glass paste bonding layer 410 and the second glass paste bonding layer 510 formed by the glass paste can be ensured, and it is beneficial to improve the reliability and consistency of production.

[0038] Reference Figures 1 to 6 , in some embodiments of a method for manufacturing an absolute pressure sensitive structure of the present invention, before printing the glass paste on the first preset position of the upper substrate sheet 100 and the second preset position of the lower substrate sheet 300 based on screen printing, it further includes: Processing the upper substrate sheet 100 to form a first boss 130, and processing the lower substrate sheet 300 to form a second boss 320; Wherein, the first boss 130 is used to abut against the pressure-sensitive membrane 200 to limit the thickness of the first glass paste bonding layer 410, and the second boss 320 is used to abut against the pressure-sensitive membrane 200 to limit the thickness of the second glass paste bonding layer 510.

[0039] By processing the upper substrate sheet 100 to form the first boss 130, when bonding the upper substrate sheet 100 to the pressure-sensitive membrane 200, for the reliability of bonding, a load pressure is applied to the upper substrate sheet 100 and the pressure-sensitive membrane 200, causing the upper substrate sheet 100 and the pressure-sensitive membrane 200 to approach each other, and the first boss 130 abuts against the pressure-sensitive membrane 200 to limit the gap size between the upper substrate sheet 100 and the pressure-sensitive membrane 200, that is, the thickness of the first glass paste bonding layer 410. At the same time, it can also control the height of the formed detection chamber to control the distance between the electrodes forming the capacitor in the detection chamber, which is beneficial to accurately control the initial capacitance value of the capacitor in the detection chamber.

[0040] Similarly, by processing the lower substrate sheet 300 to form the second boss 320, when bonding the lower substrate sheet 300 to the pressure-sensitive membrane 200, the second boss 320 abuts against the pressure-sensitive membrane 200 to limit the thickness of the second glass paste bonding layer 510, and at the same time control the height of the formed vacuum chamber to control the distance between the electrodes forming the capacitor in the vacuum chamber, which is beneficial to accurately control the initial capacitance value of the capacitor in the vacuum chamber.

[0041] Therefore, by processing and forming the first boss 130 on the upper base sheet 100 and the second boss 320 on the lower base sheet 300, it is beneficial to accurately control the three-dimensional dimensions of the first glass paste bonding layer 410 and the second glass paste bonding layer 510, making their dimensional shapes more stable and reliable, and beneficial to improving the consistency.

[0042] In some embodiments of the present invention, the first boss 130 and the second boss 320 can be processed and formed on the upper base sheet 100 and the lower base sheet 300 by means of wet etching, sandblasting, laser etching, etc. In some implementations of the present invention, a plurality of first bosses 130 can be provided on the upper base sheet 100, and a plurality of second bosses 320 can be provided on the lower base sheet 300 to increase the contact area, which is beneficial to making the contact more stable and reliable and avoiding excessive local pressure.

[0043] Reference Figure 3 and Figure 4 , in some embodiments of a method for manufacturing an absolute pressure sensitive structure of the present invention, before printing the glass paste on the first preset position of the upper base sheet 100 and the second preset position of the lower base sheet 300 based on screen printing, it further includes: Processing and forming a first upper electrode 110 and a first pad 140 connected to the first upper electrode 110 on the upper base sheet 100, and processing and forming a detection through-hole 120 on the upper base sheet 100 based on ultrasonic drilling or wet etching; Processing and forming a second upper electrode 210, a first lower electrode 220, and a second pad 230 both connected to the second upper electrode 210 and the first lower electrode 220 on the pressure-sensitive diaphragm 200; Processing and forming a second lower electrode 310 and a third pad 330 connected to the second lower electrode 310 on the lower base sheet 300; Wherein, the first upper electrode 110, the second upper electrode 210, the first lower electrode 220, and the second lower electrode 310 are defined in pattern based on photolithography or mask process and formed by magnetron sputtering or electron beam evaporation.

[0044] A first upper electrode 110 is provided on the upper base sheet 100, and a second upper electrode 210 is provided on the pressure-sensitive diaphragm 200. When the upper base sheet 100 is bonded to the pressure-sensitive diaphragm 200 through the first glass paste bonding layer 410 to form a detection chamber, the first upper electrode 110 and the second upper electrode 210 are located in the detection chamber and are arranged oppositely, and the first upper electrode 110 and the second upper electrode 210 form a first capacitor. The lower base sheet 300 is provided with a second lower electrode 310, and the pressure-sensitive diaphragm 200 is provided with a first lower electrode 220 on the other side facing away from the second upper electrode 210. When the lower base sheet 300 is bonded to the pressure-sensitive diaphragm 200 through the second glass paste bonding layer 510 to form a vacuum chamber, the first lower electrode 220 and the second lower electrode 310 are located in the vacuum chamber and are arranged oppositely, and the first lower electrode 220 and the second lower electrode 310 form a second capacitor. The upper base sheet 100 is provided with a detection through hole 120 communicating with the detection chamber. When performing pressure detection, the measured medium enters the detection chamber through the detection through hole 120. Under the action of the pressure difference with the vacuum chamber, the pressure-sensitive diaphragm 200 (forming a pressure-sensitive film 201 after scribing treatment) deforms, so that the distance between the first upper electrode 110 and the second upper electrode 210, and the distance between the first lower electrode 220 and the second lower electrode 310 change, that is, the capacitance values of the first capacitor and the second capacitor change in association with the pressure, and then corresponding electrical signals can be formed to reflect the magnitude of the pressure, achieving the effect of absolute pressure detection.

[0045] The first pad 140, the second pad 230, and the third pad 330 facilitate the connection of the subsequent processing chip 600. The first upper electrode 110, the second upper electrode 210, the first lower electrode 220, and the second lower electrode 310 are defined in shape based on a photolithography process or a mask plate process, and the shape and position of the electrodes can be accurately defined, and then the electrodes are formed by magnetron sputtering or electron beam evaporation, which is beneficial to accurately controlling the thickness of the electrodes and forming electrodes with uniform thickness. In some embodiments of the present invention, the first upper electrode 110, the second upper electrode 210, the first lower electrode 220, and the second lower electrode 310 may use chromium as a seed layer with a thickness of 20 to 200 angstroms and gold as a metal layer with a thickness of 2000 to 5000 angstroms.

[0046] It should be noted that the distance between the first upper electrode 110 and the second upper electrode 210 is related to the height of the first boss 130; the distance between the first lower electrode 220 and the second lower electrode 310 is related to the height of the second boss 320. By controlling the height of the first boss 130, the capacitance value of the first capacitor formed by the first upper electrode 110 and the second upper electrode 210 can be controlled. By controlling the height of the second boss 320, the capacitance value of the second capacitor formed by the first lower electrode 220 and the second lower electrode 310 can be controlled. In this way, the initial capacitance values of the first capacitor and the second capacitor can be accurately controlled, which is beneficial to improving the processing consistency.

[0047] Reference Figures 2 to 4 , in some embodiments of the method for manufacturing an absolute pressure sensitive structure of the present invention, printing the glass paste on the first preset position of the upper substrate 100 and the second preset position of the lower substrate 300 based on screen printing includes: Making a first alignment mark portion 710 on the screen printing plate; Making a second alignment mark portion on the upper substrate 100 and making a third alignment mark portion on the lower substrate 300; Using a CCD camera for alignment, aligning the first alignment mark portion 710 with the second alignment mark portion, printing the paste unit 720 on the screen printing plate at the first preset position of the upper substrate 100, and standing for 3 to 5 minutes for the paste to level; Using a CCD camera for alignment, aligning the first alignment mark portion 710 with the third alignment mark portion, printing the paste unit 720 on the screen printing plate at the second preset position of the lower substrate 300, and standing for 3 to 5 minutes for the paste to level.

[0048] Through the combination of screen printing and CCD alignment, the screen printing plate can accurately move the paste unit 720 onto the upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300, enabling the glass paste in the paste unit 720 to be accurately printed at the target positions on the upper substrate 100 and the lower substrate 300, and accurately controlling the amount of the glass paste, avoiding excessive overflow of the glass paste in the subsequent process. At the same time, the screen printing method can also accurately control the boundary of the glass paste, avoiding the problem of uncertain boundary caused by the strong fluidity of the glass paste, which is beneficial to improving the uniformity and repeatability. The structure of the screen printing plate is as Figure 2 shown, and the lower substrate 300 and the upper substrate 100 after screen printing are as Figure 3 and Figure 4 shown.

[0049] CCD alignment is a technology for high-precision visual positioning using a CCD camera. The CCD camera is used to collect images of the target object, and based on the marks in the images, namely the first alignment mark portion 710, the second alignment mark portion, and the third alignment mark portion, precise alignment of the object is achieved. In some embodiments of the present invention, the first alignment mark portion 710 of the screen printing plate may include a screen printing alignment mark and a wafer-level alignment mark, and the second alignment mark portion of the upper substrate 100, the third alignment mark portion of the lower substrate 300, and the fourth alignment mark portion of the subsequent pressure-sensitive film 200 may include wafer-level alignment marks.

[0050] Reference Figure 3 and Figure 4 , in some embodiments of a method for fabricating an absolute pressure-sensitive structure of the present invention, the pre-burning treatment of the upper substrate 100 and the lower substrate 300 includes: Placing the upper substrate 100 and the lower substrate 300 into a high-temperature oven; Controlling the high-temperature oven, starting from room temperature, setting a heating rate of 5 degrees Celsius per minute, heating up to 150 degrees Celsius and holding for 15 to 30 minutes to discharge the organic solvents in the glass paste, heating up to 200 degrees Celsius and holding for 30 minutes to discharge the organic binders in the glass paste, heating up to 250 degrees Celsius and holding for 15 to 30 minutes to activate the thixotropic agent in the glass paste, heating up to 300 degrees Celsius and holding for 15 to 30 minutes to crystallize the glass paste, heating up to 350 degrees Celsius and holding for 15 to 30 minutes to form a first glass paste layer 400 of the glass paste of the upper substrate 100 and a second glass paste layer 500 of the glass paste of the lower substrate 300; End the holding and wait for the high-temperature oven to cool to room temperature, then take out the upper substrate 100 and the lower substrate 300.

[0051] By setting the heating rate, the heating is carried out stably, making the temperatures of the upper substrate 100 and the lower substrate 300 more uniform, avoiding problems such as cracking caused by uneven temperature due to too fast heating, and improving reliability. Through the heating and holding curve, the glass paste is heated to achieve the purpose of discharging organic solvents and organic binders, and activating the thixotropic agent and achieving crystallization to reach the purpose of sintering and pre-forming, forming the first glass paste layer 400 and the second glass paste layer 500.

[0052] Reference Figure 5 and Figure 6 , in some embodiments of a method for fabricating an absolute pressure-sensitive structure of the present invention, a fourth alignment mark portion is provided on the pressure-sensitive film 200, and the alignment and pre-fixing of the upper substrate 100, the pressure-sensitive film 200, and the lower substrate 300 include: Using a wafer-level alignment device, adjust the relative positions of the pressure-sensitive diaphragm 200 and the lower substrate 300 to align the third alignment mark portion with the fourth alignment mark portion. Add UV glue between the pressure-sensitive diaphragm 200 and the lower substrate 300, drive the pressure-sensitive diaphragm 200 closer to the lower substrate 300 to squeeze the UV glue, and perform irradiation curing treatment on the UV glue to pre-fix the pressure-sensitive diaphragm 200 and the lower substrate 300 to form a two-layer negative film structure; Using a wafer-level alignment device, adjust the relative positions of the upper substrate 100 and the two-layer negative film structure to align the second alignment mark portion with the fourth alignment mark portion. Add UV glue between the pressure-sensitive diaphragm 200 and the upper substrate 100, drive the upper substrate 100 closer to the pressure-sensitive diaphragm 200 to squeeze the UV glue, and perform irradiation curing treatment on the UV glue to pre-fix the upper substrate 100 and the pressure-sensitive diaphragm 200 to form a three-layer negative film structure.

[0053] Using a wafer-level alignment device, based on the alignment of the third alignment mark portion and the fourth alignment mark portion, align the lower substrate 300 with the pressure-sensitive diaphragm 200 so that the second lower electrode 310 on the lower substrate 300 corresponds to the first lower electrode 220 on the pressure-sensitive diaphragm 200. Then, bond and cure through UV glue to pre-fix the relative positions of the lower substrate 300 and the pressure-sensitive diaphragm 200. Similarly, based on the alignment of the second alignment mark portion and the fourth alignment mark portion, align the upper substrate 100 with the pressure-sensitive diaphragm 200 so that the first upper electrode 110 on the upper substrate 100 corresponds to the second upper electrode 210 on the pressure-sensitive diaphragm 200. Then, bond and cure through UV glue to pre-fix the upper substrate 100 and the pressure-sensitive diaphragm 200. In this way, accurately align and fix the upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 to form a three-layer negative film structure, which is convenient for subsequent bonding processing and is beneficial to improving the stability and accuracy of bonding.

[0054] Reference Figure 1 , in some embodiments of a method for manufacturing an absolute pressure sensitive structure of the present invention, the vacuum sintering of the pre-fixed upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 includes: Place the three-layer negative film structure into a variable-load muffle furnace; Control the variable-load muffle furnace to make the fixture apply a load force of 5 kg to 10 kg to fix the three-layer negative film structure. Set a heating rate of 5 °C per minute, heat up to 520 °C and keep warm for 15 to 30 minutes. During the heat preservation, make the fixture apply a load force of 150 kg to 250 kg and a vacuum degree of 1E-3 Pa to form the first glass paste bonding layer 410 from the first glass paste layer 400 and the second glass paste bonding layer 510 from the second glass paste layer 500; End the heat preservation. Wait for the variable-load muffle furnace to cool down to 250 to 260 degrees Celsius, remove the load force of the fixture, open the furnace door of the variable-load muffle furnace when it cools down to 150 degrees Celsius, and take out the three-layer negative film structure after the variable-load muffle furnace cools down to room temperature.

[0055] By setting the heating rate, the upper substrate 100, the pressure-sensitive film 200, and the lower substrate 300 in the three-layer negative film structure can be heated stably and evenly, avoiding temperature unevenness. Maintain the vacuum degree, apply the load force, and keep warm to make the first glass paste layer 400 and the second glass paste layer form the first glass paste bonding layer 410 and the second glass paste bonding layer 510, realizing reliable bonding between the upper substrate 100 and the pressure-sensitive film 200, and reliable bonding between the lower substrate 300 and the pressure-sensitive film 200.

[0056] It should be noted that the UV glue will automatically carbonize and decompose during the vacuum sintering process. Therefore, the UV glue on the three-layer negative film structure after bonding is automatically removed.

[0057] Reference Figure 1 and Figure 7 In some embodiments of the method for manufacturing an absolute pressure sensitive structure of the present invention, the absolute pressure sensitive structure die includes an upper substrate 101, the first glass paste bonding layer 410, a pressure-sensitive film 201, the second glass paste bonding layer 510, and a lower substrate 301. After dicing the bonded upper substrate 100, the pressure-sensitive film 200, and the lower substrate 300 to form an absolute pressure sensitive structure die, it further includes: Fix the processing chip 600 on the upper substrate 101; Based on wire bonding, connect the processing chip 600 to the first pad 140 of the upper substrate 101, the second pad 230 of the pressure-sensitive film 201, and the third pad 330 of the lower substrate 301.

[0058] After dicing, the upper base film 100, the pressure-sensitive film 200, and the lower base film 300 are diced to form multiple absolute pressure sensitive structure dies. Each absolute pressure sensitive structure die corresponds to an upper substrate 101, a pressure-sensitive film 201, and a lower substrate 301. The upper substrate 101 is bonded to the pressure-sensitive film 201 through a first glass paste bonding layer 410 to form a detection chamber, and the lower substrate 301 is bonded to the pressure-sensitive film 201 through a second glass paste bonding layer 510 to form a vacuum chamber. A first upper electrode 110 and a first pad 140 connected to the first upper electrode 110 are provided on the upper substrate 101. A second upper electrode 210 and a first lower electrode 220 are respectively provided on both sides of the pressure-sensitive film 201. The pressure-sensitive film 201 is also provided with a second pad 230 that is connected to both the second upper electrode 210 and the first lower electrode 220. The lower substrate 301 is provided with a second lower electrode 310 and a third pad 330 connected to the second lower electrode 310. The first upper electrode 110 and the second upper electrode 210 are located in the detection chamber and are oppositely arranged to form a first capacitor. The first lower electrode 220 and the second lower electrode 310 are located in the vacuum chamber and are oppositely arranged to form a second capacitor.

[0059] Fix the processing chip 600 on the upper substrate 101. By means of wire bonding, connect the processing chip 600 to the first pad 140, the second pad 230, and the third pad 330, that is, electrically connect the processing chip 600 to the first upper electrode 110, the second upper electrode 210, the first lower electrode 220, and the second lower electrode 310, so that the processing chip 600 outputs corresponding electrical signals according to the capacitance value changes of the first capacitor and the second capacitor, achieving the purpose of pressure detection output.

[0060] In some embodiments of the present invention, the processing chip 600 may have an analog-to-digital conversion function of converting an analog signal into a digital signal to output the detected pressure in the form of a digital signal for subsequent processing.

[0061] In some embodiments of the present invention, the processing chip 600 may be bonded to the upper substrate 101 through epoxy glue, and then the epoxy glue is heated and cured by a blast drying oven. The heating rate is 5 degrees Celsius per minute, the curing temperature is 80 degrees Celsius to 120 degrees Celsius, and the curing time is 15 to 30 minutes to fix the processing chip 600 on the upper substrate 101.

[0062] In some embodiments of the present invention, 25um gold wires can be used for wire bonding, and the tensile strength of the gold wires is 5 to 8 grams of force.

[0063] In some embodiments of a method for manufacturing an absolute pressure sensitive structure according to the present invention, the upper base sheet 100, the pressure sensitive diaphragm 200, and the lower base sheet 300 are all quartz wafers, and the thermal expansion coefficients of the first glass paste bonding layer 410 and the second glass paste bonding layer 510 match the thermal expansion coefficient of the quartz wafer.

[0064] The upper base sheet 100, the pressure sensitive diaphragm 200, and the lower base sheet 300 all use quartz wafers. Compared with silicon materials, the elastic modulus of quartz crystals is half of that of silicon crystals. Quartz wafer materials have better flexibility. At the same size of the pressure sensitive film 201, the quartz structure has higher sensitivity. At the same time, the capacitance area formed by the quartz wafer can be made larger than that of the silicon capacitor. For the absolute pressure sensitive structure formed based on the quartz wafer, the nominal capacitance therein is one order of magnitude larger than the nominal capacitance of the silicon capacitor absolute pressure structure, which is beneficial to improving the anti-interference ability against stray capacitance.

[0065] The thermal expansion coefficients of the first glass paste bonding layer 410 and the second glass paste bonding layer 510 match the quartz wafer material, that is, they match the thermal expansion coefficients of the upper base sheet 100, the pressure sensitive diaphragm 200, and the lower base sheet 300, which is beneficial to avoiding problems such as cracking and separation caused by large differences in thermal expansion coefficients resulting in large differences in the degree of material expansion. At the same time, the matching of thermal expansion coefficients can reduce thermal stress and mechanical stress, avoid problems such as cracking and delamination, and avoid the distortion of the pressure sensitive film 201 due to gravity in the absolute pressure sensitive structure after division, avoid temperature drift, and is beneficial to improving the bonding reliability between the upper substrate 101 and the pressure sensitive film 201 and making the pressure measurement more accurate and reliable.

[0066] The following describes an absolute pressure sensitive structure provided by the present invention. The absolute pressure sensitive structure described below can be correspondingly referred to the method for manufacturing an absolute pressure sensitive structure described above.

[0067] Reference Figures 7 to 14, the present invention also provides an absolute pressure sensitive structure, which is characterized by including an upper substrate 101, a first glass paste bonding layer 410, a pressure sensitive film 201, a second glass paste bonding layer 510, and a lower substrate 301. The upper substrate 101 is connected to the pressure sensitive film 201 through the first glass paste bonding layer 410 to form a detection chamber. The lower substrate 301 is connected to the pressure sensitive film 201 through the second glass paste bonding layer 510 to form a vacuum chamber. The upper substrate 101 is provided with a detection through hole 120 communicating with the detection chamber and a first upper electrode 110. The pressure sensitive film 201 is provided with a second upper electrode 210 and a first lower electrode 220. The lower substrate 301 is provided with a second lower electrode 310. The first upper electrode 110 and the second upper electrode 210 are located in the detection chamber. The first lower electrode 220 and the second lower electrode 310 are located in the vacuum chamber; Wherein, the absolute pressure sensitive structure is obtained by the manufacturing method of an absolute pressure sensitive structure as described above.

[0068] The upper substrate 101 is provided with a first upper electrode 110. The pressure sensitive film 201 is provided with a second upper electrode 210. The upper substrate 101 is bonded to the pressure sensitive film 201 through the first glass paste bonding layer 410 to form a detection chamber. The first upper electrode 110 and the second upper electrode 210 are located in the detection chamber and are oppositely arranged. The first upper electrode 110 and the second upper electrode 210 form a first capacitor. The lower substrate 301 is provided with a second lower electrode 310. The pressure sensitive film 201 is provided with a first lower electrode 220 on the other side facing away from the second upper electrode 210. The lower substrate 301 is bonded to the pressure sensitive film 201 through the second glass paste bonding layer 510 to form a vacuum chamber. The first lower electrode 220 and the second lower electrode 310 are located in the vacuum chamber and are oppositely arranged. The first lower electrode 220 and the second lower electrode 310 form a second capacitor. The upper substrate 101 is provided with a detection through hole 120 communicating with the detection chamber. When performing pressure detection, the measured medium enters the detection chamber through the detection through hole 120. Under the action of the pressure difference with the vacuum chamber, the pressure sensitive film 201 deforms, so that the distance between the first upper electrode 110 and the second upper electrode 210, and the distance between the first lower electrode 220 and the second lower electrode 310 change. That is, the capacitance values of the first capacitor and the second capacitor are correlated with the pressure and change, and then corresponding electrical signals can be formed to reflect the magnitude of the pressure, achieving the effect of absolute pressure detection.

[0069] By means of screen printing, glass paste is printed on the upper substrate 100 and the lower substrate 300. Utilizing the precision of screen printing, it is ensured that the glass paste can be accurately printed at the desired positions, and screen printing can control the boundary of the glass paste to prevent the fluidity of the glass paste from causing fluctuations in the size of the glass paste. Through pre-burning treatment, the glass paste on the upper substrate 100 is cured to form the first glass paste layer 400, and the glass paste on the lower substrate 300 is cured to form the second glass paste layer 500 to pre-shape the glass paste and avoid the influence of the size change of the glass paste on the reliability and sealing degree of subsequent bonding. The upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 are aligned and pre-fixed with each other to facilitate subsequent bonding connection. The pre-fixed upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 are subjected to vacuum sintering. The first glass paste layer 400 forms the first glass paste bonding layer 410 to bond the upper substrate 100 and the pressure-sensitive diaphragm 200 to form a detection chamber, and the second glass paste layer 500 forms the second glass paste bonding layer 510 to bond the lower substrate 300 and the pressure-sensitive diaphragm 200 to form a vacuum chamber. The pre-fixed upper substrate 100, the pressure-sensitive diaphragm 200, and the lower substrate 300 after vacuum sintering are subjected to dicing treatment to form a plurality of absolute pressure sensitive structure dies, including the upper substrate 101, the first glass paste bonding layer 410, the pressure-sensitive film 201, the second glass paste bonding layer 510, and the lower substrate 301.

[0070] Therefore, based on the glass paste bonding method, by utilizing the printing precision of screen printing and the accurate control of the boundary of the glass paste, the sizes and shapes of the formed first glass paste bonding layer 410 and second glass paste bonding layer 510 can be accurately controlled, ensuring the bonding structural strength and sealing degree, which is beneficial to improving the stability and reliability of the structure. At the same time, the glass paste bonding method does not require the use of a large amount of metal materials. Screen printing of glass paste can accurately control the amount of glass paste, which is beneficial to reducing the implementation cost, and has high production efficiency and high repeatability, which is beneficial to ensuring the yield rate of production.

[0071] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0072] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0073] All actions of obtaining signals, information, or data in this application are carried out on the premise of complying with the corresponding data protection regulations and policies of the location and with the authorization given by the owner of the corresponding device.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing an absolute pressure sensitive structure, characterized in that, Including: Printing glass paste on the first preset position of the upper substrate (100) and the second preset position of the lower substrate (300) based on screen printing; Performing a pre-burning treatment on the upper substrate (100) and the lower substrate (300) so that the glass paste on the upper substrate (100) forms a first glass paste layer (400) and the glass paste on the lower substrate (300) forms a second glass paste layer (500); Aligning and pre-fixing the upper substrate (100), the pressure-sensitive diaphragm (200), and the lower substrate (300); Performing vacuum sintering on the pre-fixed upper substrate (100), the pressure-sensitive diaphragm (200), and the lower substrate (300) so that the first glass paste layer (400) forms a first glass paste bonding layer (410) and the second glass paste layer (500) forms a second glass paste bonding layer (510), the first glass paste bonding layer (410) is bonded to the upper substrate (100) and the pressure-sensitive diaphragm (200) respectively to form a detection chamber, and the second glass paste bonding layer (510) is bonded to the lower substrate (300) and the pressure-sensitive diaphragm (200) respectively to form a vacuum chamber; Performing a dicing process on the bonded upper substrate (100), the pressure-sensitive diaphragm (200), and the lower substrate (300) to form a bare die of an absolute pressure sensitive structure.

2. The method for manufacturing an absolute pressure sensitive structure according to claim 1, wherein Before printing the glass paste on the first preset position of the upper substrate (100) and the second preset position of the lower substrate (300) based on screen printing, it further includes: Processing the upper substrate (100) to form a first boss (130), and processing the lower substrate (300) to form a second boss (320); Wherein, the first boss (130) is used to abut against the pressure-sensitive diaphragm (200) to limit the thickness of the first glass paste bonding layer (410), and the second boss (320) is used to abut against the pressure-sensitive diaphragm (200) to limit the thickness of the second glass paste bonding layer (510).

3. A method for manufacturing an absolute pressure sensitive structure according to claim 1 or 2, characterized in that, Before printing the glass paste on the first preset position of the upper substrate (100) and the second preset position of the lower substrate (300) based on screen printing, it further includes: Processing the upper substrate (100) to form a first upper electrode (110) and a first pad (140) connected to the first upper electrode (110), and processing a detection through hole (120) on the upper substrate (100) based on ultrasonic drilling or wet etching; Processing the pressure-sensitive diaphragm (200) to form a second upper electrode (210), a first lower electrode (220), and a second pad (230) both connected to the second upper electrode (210) and the first lower electrode (220); Processing the lower substrate (300) to form a second lower electrode (310) and a third pad (330) connected to the second lower electrode (310); Among them, the first upper electrode (110), the second upper electrode (210), the first lower electrode (220), and the second lower electrode (310) are defined in pattern based on a lithography process or a mask plate process and are formed by magnetron sputtering or electron beam evaporation.

4. The method for manufacturing an absolute pressure sensitive structure according to claim 1, characterized in that, The printing of the glass paste on the first preset position of the upper substrate (100) and the second preset position of the lower substrate (300) based on screen printing includes: Fabricating a first alignment mark portion (710) on the screen printing plate; Fabricating a second alignment mark portion on the upper substrate (100) and a third alignment mark portion on the lower substrate (300); Performing alignment using a CCD camera, aligning the first alignment mark portion (710) with the second alignment mark portion, printing the paste unit (720) on the screen printing plate at the first preset position of the upper substrate (100), and standing for 3 to 5 minutes for the paste to level; Performing alignment using a CCD camera, aligning the first alignment mark portion (710) with the third alignment mark portion, printing the paste unit (720) on the screen printing plate at the second preset position of the lower substrate (300), and standing for 3 to 5 minutes for the paste to level.

5. The method for manufacturing an absolute pressure sensitive structure according to claim 1, wherein The pre-baking treatment of the upper substrate (100) and the lower substrate (300) includes: Placing the upper substrate (100) and the lower substrate (300) into a high-temperature oven; Controlling the high-temperature oven, starting from room temperature, setting a heating rate of 5 °C per minute, heating to 150 °C and holding for 15 to 30 minutes to discharge the organic solvents in the glass paste, heating to 200 °C and holding for 30 minutes to discharge the organic binders in the glass paste, heating to 250 °C and holding for 15 to 30 minutes to activate the thixotropic agent in the glass paste, heating to 300 °C and holding for 15 to 30 minutes to crystallize the glass paste, heating to 350 °C and holding for 15 to 30 minutes to form a first glass paste layer (400) of the glass paste on the upper substrate (100) and a second glass paste layer (500) of the glass paste on the lower substrate (300); Ending the holding and taking out the upper substrate (100) and the lower substrate (300) after the high-temperature oven cools to room temperature.

6. The method for manufacturing an absolute pressure sensitive structure according to claim 4, characterized in that A fourth alignment mark portion is provided on the pressure-sensitive diaphragm (200). The alignment and pre-fixing of the upper substrate (100), the pressure-sensitive diaphragm (200), and the lower substrate (300) include: Using a wafer-level alignment device, adjust the relative positions of the pressure-sensitive diaphragm (200) and the lower substrate (300) to align the third alignment mark portion with the fourth alignment mark portion. Add UV glue between the pressure-sensitive diaphragm (200) and the lower substrate (300), drive the pressure-sensitive diaphragm (200) closer to the lower substrate (300) to squeeze the UV glue, and perform irradiation curing treatment on the UV glue to pre-fix the pressure-sensitive diaphragm (200) and the lower substrate (300) to form a two-layer negative film structure; Using a wafer-level alignment device, adjust the relative positions of the upper substrate (100) and the two-layer negative film structure to align the second alignment mark portion with the fourth alignment mark portion. Add UV glue between the pressure-sensitive diaphragm (200) and the upper substrate (100), drive the upper substrate (100) closer to the pressure-sensitive diaphragm (200) to squeeze the UV glue, and perform irradiation curing treatment on the UV glue to pre-fix the upper substrate (100) and the pressure-sensitive diaphragm (200) to form a three-layer negative film structure.

7. The method for manufacturing an absolute pressure sensitive structure according to claim 6, characterized in that, The vacuum sintering of the pre-fixed upper substrate (100), pressure-sensitive diaphragm (200), and lower substrate (300) includes: Placing the three-layer negative film structure into a variable-load muffle furnace; Controlling the variable-load muffle furnace to apply a load force of 5 kg to 10 kg by the fixture to fix the three-layer negative film structure, setting a heating rate of 5 °C per minute, heating to 520 °C and holding for 15 to 30 minutes, and applying a load force of 150 kg to 250 kg and a vacuum degree of 1E-3 Pa by the fixture during the holding period to form the first glass paste bonding layer (410) of the first glass paste layer (400) and the second glass paste bonding layer (510) of the second glass paste layer (500); End the holding. Wait for the variable-load muffle furnace to cool to 250 °C to 260 °C, remove the load force of the fixture, open the furnace door of the variable-load muffle furnace when it cools to 150 °C, and take out the three-layer negative film structure after the variable-load muffle furnace cools to room temperature.

8. A method for manufacturing an absolute pressure sensitive structure according to claim 1, characterized in that, The absolute pressure sensitive structure die includes an upper substrate (101), the first glass paste bonding layer (410), a pressure-sensitive film (201), the second glass paste bonding layer (510), and a lower substrate (301). After performing dicing treatment on the bonded upper substrate (100), pressure-sensitive diaphragm (200), and lower substrate (300) to form an absolute pressure sensitive structure die, it further includes: Fixing the processing chip (600) to the upper substrate (101); Based on wire bonding, connecting the processing chip (600) to the first pad (140) of the upper substrate (101), the second pad (230) of the pressure-sensitive film (201), and the third pad (330) of the lower substrate (301).

9. A method for manufacturing an absolute pressure sensitive structure according to claim 1, characterized in that The upper base sheet (100), the pressure-sensitive diaphragm (200), and the lower base sheet (300) are all quartz wafers, and the thermal expansion coefficients of the first glass paste bonding layer (410) and the second glass paste bonding layer (510) match the thermal expansion coefficient of the quartz wafer.

10. An absolute pressure sensitive structure, characterized in that, It includes an upper substrate (101), a first glass paste bonding layer (410), a pressure-sensitive film (201), a second glass paste bonding layer (510), and a lower substrate (301). The upper substrate (101) is connected to the pressure-sensitive film (201) through the first glass paste bonding layer (410) to form a detection chamber. The lower substrate (301) is connected to the pressure-sensitive film (201) through the second glass paste bonding layer (510) to form a vacuum chamber. The upper substrate (101) is provided with a detection through hole (120) and a first upper electrode (110) communicating with the detection chamber. The pressure-sensitive film (201) is provided with a second upper electrode (210) and a first lower electrode (220). The lower substrate (301) is provided with a second lower electrode (310). The first upper electrode (110) and the second upper electrode (210) are located in the detection chamber. The first lower electrode (220) and the second lower electrode (310) are located in the vacuum chamber; Among them, the absolute pressure sensitive structure is obtained by the manufacturing method of an absolute pressure sensitive structure according to any one of claims 1 to 9.

Images