An array type pressure measuring device

Abstract

The present invention discloses an array pressure measuring device, including: a piezoresistive sensitive chip, which is used to apply a reference pressure on its front side and an external gas pressure on its back side to generate a pressure difference; a circuit system, which is used to convert the generated pressure difference into an electrical signal output proportional to the pressure change and process and calculate; and a gas path system, which is used to provide gas pressure and act on both sides of the piezoresistive sensitive chip to generate the pressure difference. In the present invention, the alloy substrate and the piezoresistive sensitive chip are directly bonded with a packaging sealant, and the PCB board is located on both sides of the piezoresistive sensitive chip for electrical interconnection, which can reduce assembly stress and provide support for the precise control of the stress and temperature state of the piezoresistive sensitive chip, facilitate the disassembly and individual replacement of the piezoresistive sensitive chip or related circuit system components, and the multi-layer circuit chips are stacked and integrated. The internal integrated gas path system is conducive to the miniaturization of the entire pressure measuring device assembly.

Description

Technical Field

[0001] The invention relates to the field of microelectronic packaging, in particular to an array type pressure measuring device. Background Art

[0002] Array-type multi-channel pressure measurement devices are widely used in wind tunnel tests or flight tests, and can realize multi-channel rapid measurement of pressure. Among them, MEMS piezoresistive sensitive chips are the core components of pressure measurement devices, which have a decisive influence on the overall performance of pressure measurement devices. At present, the comprehensive performance improvement of array-type multi-channel pressure measurement devices faces some core problems that need to be solved and optimized. First, stress and strain will be introduced during the assembly process of the device, affecting the performance of the piezoresistive sensitive chip. Due to the difference in thermal expansion coefficients between the piezoresistive sensitive chip and other components of the device, the piezoresistive sensitive chip forms a complex heat conduction path with the external environment when it is working. The heat of the chip itself and the temperature field of the environment in which the device is located cause the temperature state of the piezoresistive sensitive chip to change, and the thermal stress and strain will also change. These factors cause performance drift and are difficult to accurately predict, which restricts the long-term stability and comprehensive accuracy of the product. To solve this problem, on the one hand, it is necessary to control the stress generated during the assembly process, and on the other hand, it is necessary to accurately control the stress and temperature distribution state of the chip during the working process, or accurately obtain its state changes, and solve it through subsequent circuit system compensation methods. In the representative technical solutions currently disclosed, the pressure gauge chip is assembled on the ceramic sheet-PCB circuit board-metal plate stack, supplemented by adhesive materials, to solve the stress and strain problems in the assembly process and the stress problems caused by the mismatch of thermal expansion coefficients, and the working state temperature of the piezoresistive sensitive chip is obtained by assembling a temperature sensor mounted on the circuit board; however, the thermodynamic properties of the ceramic sheet-PCB stack are complex, and the temperature sensor assembled on the circuit board cannot accurately characterize the temperature state of the piezoresistive sensitive chip in the working state, especially the temperature state of the piezoresistive sensitive strip, which limits the accuracy of temperature compensation. In addition, other problems with the current device are that it is difficult to maintain the chip level, and it is usually impossible to disassemble and maintain or replace a single chip in the pressure measurement device. Summary of the invention

[0003] The object of the present invention is to provide an array pressure measurement device to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An array pressure measuring device, comprising:

[0006] A piezoresistive sensitive chip, a reference pressure is applied to the front side of the piezoresistive sensitive chip, and an external gas pressure is applied to the back side to generate a pressure difference. A piezoresistive strip, a passivation layer and a pad are formed on the front side of the piezoresistive sensitive chip, and an open cavity is formed on the back side of the piezoresistive sensitive chip; a circuit system is integrated on a first circuit chip and a second circuit chip, the circuit system includes a temperature sensor chip, an instrument amplifier circuit, an ADC module and an MCU, and the circuit system is used to convert the pressure difference generated by the piezoresistive sensitive chip into an electrical signal output proportional to the pressure change and process and calculate; an air path system is used to provide air pressure and act on both sides of the piezoresistive sensitive chip to generate the pressure difference, and the air path system is formed by sealing and connecting the back side cavity of the piezoresistive sensitive chip, and the first alloy substrate, the second alloy substrate and the third alloy substrate; the first alloy substrate, the second alloy substrate and the third alloy substrate are provided with air guide holes running through the front and back sides and a reference pressure air path for setting a reference pressure; the first alloy substrate is provided with a boss structure, the piezoresistive sensitive chip is fixed on the boss structure of the first alloy substrate, and the boss structure of the first alloy substrate is provided with air guide holes, and the air guide holes are connected to the back side cavity of the piezoresistive sensitive chip.

[0007] Furthermore, the first alloy substrate is provided with an open cavity and a fixing structure for accommodating and fixing the first circuit chip and the second circuit chip.

[0008] Furthermore, an open cavity and a fixing structure are provided on the back side of the first alloy substrate for placing the second alloy substrate and the third alloy substrate.

[0009] Furthermore, the second alloy substrate and the third alloy substrate are placed in an open cavity on the same side of the first alloy substrate, or are divided into two parts and placed on two sides of the first alloy substrate respectively.

[0010] Furthermore, the first circuit chip is placed in the open cavity on the front side of the first alloy substrate, and the second circuit chip is placed in the open cavity on the back side of the first alloy substrate; the second alloy substrate and the third alloy substrate are placed in the same open cavity on the side of the first alloy substrate, or they can be divided into two parts and placed on both sides of the first alloy substrate.

[0011] Furthermore, the first circuit chip is connected to the first alloy substrate with reference to the mounting position of the piezoresistive sensitive chip, and the second circuit chip is connected to the step structure of the side wall of the first alloy substrate; stainless steel pipe air ports corresponding to the air guide holes are respectively arranged on the outer side of the third alloy substrate.

[0012] Furthermore, the air guide holes are divided into a calibration passage, a test passage, and a temperature control passage;

[0013] The second alloy substrate is movable, and the array pressure measurement device can be switched between the calibration passage and the test passage or between the temperature control passage and the test passage by moving the second alloy substrate;

[0014] The array pressure measurement device also includes a device for driving the second alloy substrate to move. The device for driving the second alloy substrate to move is an electromagnet driver or a magnetostrictive driver arranged on the side wall of the first alloy substrate, or a convex shaft structure located on the second alloy substrate and connected to the outside of the package body, so as to realize the movement of the second alloy substrate.

[0015] Furthermore, the temperature sensor chip is implemented by using the piezoresistive sensitive chip.

[0016] Furthermore, after the open cavity on the back of the piezoresistive sensitive chip is evacuated, another piece of silicon or glass is bonded to the back of the piezoresistive sensitive chip to seal the open cavity, thereby forming an absolute pressure piezoresistive sensitive chip.

[0017] Furthermore, an interconnection substrate with air guide holes is arranged between the piezoresistive sensitive chip and the first alloy substrate boss.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The alloy substrate and the piezoresistive sensitive chip are directly bonded with packaging glue, and the PCB board is located on both sides of the piezoresistive sensitive chip for electrical interconnection, which can reduce assembly stress; at the same time, the alloy substrate is directly connected to the piezoresistive sensitive chip as a heat sink, and the thermodynamic characteristics between the two are simple. Only the temperature sensor assembled on the circuit board can accurately calculate the temperature distribution of the pressure chip under working conditions, which is easy to accurately control thermal stress and helps heat dissipation management; in addition, a cooling channel is set inside the alloy to control the temperature of the array piezoresistive sensitive chip, which is conducive to maintaining long-term stability and comprehensive accuracy and avoiding device performance drift.

[0020] (2) The pressure measurement device has chip-level maintainability. Multiple circuit chips are stacked and integrated, which makes it easy to disassemble and replace the piezoresistive sensitive chip or related circuit system components separately. The gas path system can also be disassembled for cleaning and maintenance.

[0021] (3) The first alloy substrate has cavities on multiple sides for placing array-type piezoresistive sensing chips and circuit systems, and the internal integrated gas path system is conducive to the miniaturization of the entire pressure measurement device assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of Example 1 of the present invention.

[0023] Figure 2Schematic diagram of a differential pressure piezoresistive sensing chip according to Example 1 of the present invention.

[0024] Figure 3 This is a schematic diagram of a piezoresistive sensitive chip for temperature compensation according to Example 1 of the present invention.

[0025] Figure 4 for Figure 3 Schematic diagram of the cross-section at a-a'.

[0026] Figure 5 This is a schematic diagram of the first circuit chip integration of the present invention.

[0027] Figure 6 This is a schematic diagram of the second circuit chip integration of the present invention.

[0028] Figure 7 It is a schematic diagram of the first alloy substrate of the present invention.

[0029] Figure 8 for Figure 7 Schematic diagram of the cross-section at b-b'.

[0030] Fig. 9 It is a schematic diagram of the second alloy substrate of the present invention.

[0031] Fig.10 for Fig. 9 Schematic diagram of the cross-section at c-c'.

[0032] Fig.11 for Fig. 9 Schematic diagram on the back.

[0033] Fig.12 It is a schematic diagram of the third alloy substrate of the present invention.

[0034] Fig.13 for Fig.12 Schematic diagram of the cross-section at d-d'.

[0035] Fig.14 This is a schematic diagram of the structure of Example 2 of the present invention.

[0036] Fig.15 This is another structural schematic diagram of embodiment 2 of the present invention.

[0037] Fig.16 This is a schematic diagram of the structure of Example 3 of the present invention.

[0038] Fig.17 This is a schematic diagram of the structure of Example 4 of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "upper / lower end", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting / sleeving", "sleeve connection", "connection", etc. should be understood in a broad sense. For example, "connection" 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 indirectly connected through an intermediate medium, or it can be the internal communication of two components. 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.

[0042] See also Figure 1-13 , the present invention provides a technical solution:

[0043] Array pressure measurement device and integrated assembly method Figure 1 As shown, the pressure measuring device mainly includes a piezoresistive sensitive chip 000 , a circuit system 100 and a gas circuit system 200 .

[0044] refer to Figure 2-4 The piezoresistive sensitive chip 000 is a silicon substrate. A piezoresistive strip 001, a passivation layer 002 and a Pad 003 are formed on the front of the piezoresistive sensitive chip 000 through processes such as epitaxy, oxidation, diffusion and sputtering. An open cavity 004 is formed on the back of the piezoresistive sensitive chip 000 through an etching process. Pad 004 includes at least one power pad, one ground pad and two signal pads. A reference pressure P1 is applied to the front of the piezoresistive sensitive chip 000, and the external gas pressure P2 is applied to the open cavity 004 on the back of the piezoresistive sensitive chip 000 through the gas path system 200. The pressure difference between the two ends of the piezoresistive sensitive chip 000 is converted into an electrical signal proportional to the pressure change through the circuit system 100 and processed and calculated.

[0045] In one embodiment of the present invention, the piezoresistive sensing chip further includes an absolute pressure piezoresistive sensing chip. The absolute pressure piezoresistive sensing chip is formed by evacuating the open cavity on the back of the piezoresistive sensing chip 000a, and then bonding another silicon wafer to the back of the piezoresistive sensing chip to seal the open cavity. The air pressure in the open cavity on the back of the absolute pressure piezoresistive sensing chip is zero and cannot be adjusted.

[0046] refer to Figure 5-6 The circuit system 100 includes a piezoresistive sensing chip 000, a temperature sensor chip 101, an instrument amplifier circuit 102, an ADC 103 module and an MCU 104, etc.; the piezoresistive sensing chip 000 and the temperature sensor chip 101 are integrated on a first circuit chip 110 by wire bonding, and the instrument amplifier circuit 102, the ADC 103 module and the MCU 104, etc. are integrated on a second circuit chip 120 by wire bonding or mounting; the first circuit chip 110 and the second circuit chip 120 are stacked and placed in parallel, and the two are interconnected by a hose line or a pin header 105; the signal generated by the piezoresistive sensing chip 000 due to the pressure difference is amplified by the instrument amplifier circuit and enters the ADC module, then enters the MCU processing unit, and finally enters the visual interface for processing and calculation.

[0047] In this embodiment, the first circuit chip 110 integrates a 4x8 array of piezoresistive sensing chips 000a, and the number of piezoresistive sensing chips 000a can be further expanded according to demand to add more channels; optionally, the first circuit chip 110 can also integrate a temperature sensor chip 101 for real-time detection of the temperature of the piezoresistive sensing chip 000;

[0048] Preferably, the temperature sensor 101 is implemented by a piezoresistive sensitive chip 000b, see Figure 3When the piezoresistive sensitive chip is used for implementation, the piezoresistive sensitive chip 000b is directly bonded to the boss 217 of the first alloy substrate 210 by packaging glue. The boss 217 is provided with a gas channel, one end of which is connected to the back cavity 004 of the piezoresistive sensitive chip 000b, and the other end is connected to the working cavity of the piezoresistive sensitive chip 000b, that is, the front open cavity 213 of the first alloy substrate 210, so that the pressure difference on both sides of the membrane surface of the piezoresistive sensitive chip is set to zero, and no deformation will be generated, so that the piezoresistive sensitive chip 000b always maintains a zero-point output state, and the change in resistance only reflects its temperature change; 000b has the same working voltage conditions as other piezoresistive sensitive chips 000, and works at the same time. When the temperature of the environment in which the piezoresistive sensitive chip 000a is located changes and the temperature changes due to the thermoelectric effect of the piezoresistive strip 001 on the surface of the piezoresistive sensitive chip 000, the resistance change of the piezoresistive strip 000b can be extracted by testing for evaluation and characterization, which is used for device temperature compensation and improves the temperature measurement accuracy used for temperature compensation.

[0049] In one embodiment of the present invention, the height of the boss 217 is determined according to the difference between the thickness of the first circuit chip 110 and the thickness of the piezoresistive sensor chip 000, so that the height difference between the front surface of the piezoresistive sensor chip 000 and the upper surface of the first circuit chip 110 is less than 200 microns.

[0050] refer to Figure 7-13 The gas path system 200 is sealed and connected in sequence by the back cavity 004 of the piezoresistive sensitive chip, the first alloy substrate 210 with gas-conducting holes, the second alloy substrate 220, and the third alloy substrate 230; wherein the first alloy substrate 210 has gas-conducting holes 211 running through the front and back sides and a reference pressure gas path 212 for setting the reference pressure; the second alloy substrate 220 has gas-conducting holes 221 running through the front and back sides and a reference pressure gas path 222 for setting the reference pressure; wherein the gas-conducting holes 221 are divided into a calibration path 221a, a test path 221b, and a temperature control path 221c, and the calibration path 221a and the temperature control path 221c are combined into a first path; the third alloy substrate 230 has gas-conducting holes 231 running through the front and back sides and a reference pressure gas path 232 for setting the reference pressure; in addition, the back side of the third alloy substrate 230 also has a calibration conversion path inlet 233 and a temperature control conversion path inlet 234. The second alloy substrate 220 is mobile and can be switched between the calibration passage 221a and the test passage 221b or between the temperature control passage 221c and the test passage 221b. A sealing ring 201 is provided between the alloy substrates to ensure the sealing of the gas path system.

[0051] In the calibration mode, external air enters from the calibration conversion channel inlet 233 of the third alloy substrate 230, passes through the air guide port 231, enters the calibration passage 221a of the second alloy substrate 220, then enters the air guide hole 211 of the first alloy substrate 210, and finally enters the back cavity 004 of the piezoresistive sensitive chip 000 attached to the upper part of the first alloy substrate 210.

[0052] In the test mode, external air enters through the multiple air holes 231 of the third alloy substrate 230, passes through the test passage 221b of the second alloy substrate 220, enters the air holes 211 of the first alloy substrate 210, and finally enters the back cavity 004 of the piezoresistive sensitive chip 000 attached to the upper part of the first alloy substrate 210. Each piezoresistive sensitive chip 000 can be measured individually.

[0053] In the temperature control mode, the external gas enters from the temperature control conversion channel inlet 234 of the third alloy substrate 230, passes through the air guide port 231, enters the temperature control passage 221c of the second alloy substrate 220, and then enters the air guide hole 211 of the first alloy substrate 210, and finally enters the back cavity 004 of the piezoresistive sensitive chip 000 attached to the upper part of the first alloy substrate 210; the external gas can be selected as a cooling medium such as nitrogen or helium; the temperature control mode can be turned on at the same time in the test mode.

[0054] In the reference pressure setting mode, external gas enters from the reference pressure gas path 232 of the third alloy substrate 230, passes through the reference pressure gas path 222 of the second alloy substrate, enters the reference pressure gas path of the first alloy substrate, and finally enters the back cavity 004 of the piezoresistive sensitive chip 000 attached to the upper part of the first alloy substrate 210, completing the reference pressure setting of the piezoresistive sensitive chip.

[0055] The device first works in the calibration mode. The calibration conversion channel inlet 233 is connected to a high-precision air pressure calibration source. The reference air pressure is set at a fixed air pressure value. The device is placed in a device that can accurately control the temperature and gradually adjusts the input air pressure value. Each piezoresistive sensitive chip 000 signal is amplified by the instrument amplifier circuit 102, and the ADC103 module converts it into a digital signal and transmits it to the MCU104. Synchronously, the temperature sensor 101 signal is amplified and converted into a digital signal by ADC103 and transmitted to the MCU104. The MCU104 module will record the calibration air pressure input and temperature, and form a fitting relationship between each pressure sensitive chip 000 and temperature output and the air pressure input and temperature setting value under different temperature conditions, and store it.

[0056] In the test mode, the second alloy substrate 220 is moved to the test passage 221b, each piezoresistive sensitive chip 000 corresponds to a single air guide hole one by one, and the reference air pressure is set to a stable value as needed. The external air pressure input generates a pressure difference at both ends of the piezoresistive sensitive chip 000 and the temperature sensor 101 obtains a signal, which is amplified by the instrument amplifier circuit 102 and converted by ADC103 and obtained by MCU104. The MCU104 module will automatically find the fitting relationship between the output of each pressure sensitive chip 000 and the air pressure input under this temperature condition according to the temperature sensor 101 signal, and use the fitting relationship to obtain the voltage signal output value of each pressure sensitive chip 000.

[0057] During the test, according to the application scenario requirements, cooling gas can be input into the temperature control passage 221c to maintain the temperature field of the piezoresistive sensor chip 000.

[0058] The first alloy substrate 210 has an open cavity 213 on the front side, which is used to accommodate the first circuit chip 110 and the second circuit chip 120; wherein the first circuit chip 110 is connected to the first alloy substrate 210 by sealing adhesive or threading with reference to the mounting position of the piezoresistive sensitive chip 000; the second circuit chip 120 is connected to the step structure 214 on the side wall of the first alloy substrate 210 by sealing adhesive or threading; the first alloy substrate 210 also has a step structure 215 on the top, which is used to bond the fourth alloy substrate 240 to seal the open cavity 212, and the bonding method can be sealing adhesive or threading, etc., which is convenient for subsequent disassembly and maintenance of the piezoresistive sensitive chip or circuit chip. The first alloy substrate 210 has an open cavity 216 on the back side, which is used to place the second alloy substrate 220 and the third alloy substrate 230; optionally, a boss 217 is also provided in the front cavity of the first alloy substrate 210 to match the height difference between the piezoresistive sensitive chip 000 and the first circuit chip 110, which is convenient for wire bonding. Sealing rings 201 are provided at all steps of the first alloy substrate 210 to ensure the airtightness of the system. An electromagnet driver or magnetostrictive driver 219 is provided on the side wall of the first alloy substrate 210 to achieve the movement of the second alloy substrate;

[0059] Optionally, the movement function of the second alloy substrate 220 can also be achieved by manually moving the convex shaft structure 223 (as shown in the schematic diagram of embodiment 2) located on the second alloy substrate 220 and connected to the outside of the package body to achieve conversion between calibration or temperature control and test modes;

[0060] The third alloy substrate 230 is provided with stainless steel pipe gas ports 235 corresponding to the gas guide holes or functional modules on the outside. A hose 236 may be placed outside the stainless steel pipe 235 to facilitate connection with external components to be tested or operating devices.

[0061] Example 2

[0062] refer to Fig.14 , 15 The difference between this embodiment and embodiment 1 is that the second alloy substrate 220 and the third alloy substrate 230 are placed in the open cavity 217 on the same side of the first alloy substrate 210, and can also be divided into two parts and placed on both sides of the first alloy substrate 210; the air guide holes 211 are correspondingly converted according to the position of the second alloy substrate 220. The straight air guide hole structure in embodiment 1 connects the front and back of the first alloy substrate 210, and the air guide holes 211 in this embodiment connect the front and the same or different sides of the first alloy substrate 210; the rest refer to embodiment 1.

[0063] Example 3

[0064] refer to Fig.16 The difference between this embodiment and embodiment 1 is that during assembly, the first circuit chip 110 is placed in the open cavity 212 on the front of the first alloy substrate 210, and the second circuit chip 120 is placed in the open cavity 004 on the back of the first alloy substrate 210, and they are connected by bonding or bolts, etc., to facilitate maintenance and replacement. The second alloy substrate 220 and the third alloy substrate 230 are placed in the same side open cavity 217 of the first alloy substrate 210, and can also be divided into two parts and placed on both sides of the first alloy substrate 210, and the air guide holes 130 are correspondingly converted according to the position of the second alloy substrate, as in embodiment 2; the top and bottom of the first alloy substrate 210 are respectively provided with fourth alloy substrates 240 for sealing the open cavity; the rest refer to embodiment 1.

[0065] Example 4

[0066] refer to Fig.17 The piezoresistive sensing chip in this embodiment is an absolute pressure piezoresistive sensing chip 000c. The piezoresistive sensing chip 000c is a silicon substrate. A piezoresistive strip 001, a passivation layer 002, a pad 003 and a solder ball 006 are formed on the front of the piezoresistive sensing chip 000c by epitaxy, oxidation, diffusion, sputtering and other processes; an open cavity 004 is formed on the back of the piezoresistive sensing chip 000c by an etching process; after the back open cavity 004 is evacuated, another piece of silicon or glass 010 is bonded to the back of the piezoresistive sensing chip 000c to seal the open cavity 004 and form an absolute pressure piezoresistive sensing chip 000c. The pad 004 includes at least one power pad, one ground pad and two signal pads.

[0067] To be compatible with the assembly system described in Example 1, a solder ball is formed on the front of the piezoresistive sensitive chip 000 and is flip-chip soldered on an interconnect substrate 020 with air guide holes, on which there is an electrical wiring layer and a pad corresponding to the solder ball; SU8 or BCB glue is then used to seal the gap between the piezoresistive sensitive chip 000 and the ceramic sheet 020 to form a sealing ring 021; the sealing glue is used to bond the bonding bodies of the piezoresistive sensitive chip 000 and the interconnect substrate 020 one by one to the air guide holes corresponding to the first alloy substrate 210; the first alloy substrate 210 is also provided with a first circuit chip 110, and the interconnect substrate 020 is electrically connected to the first circuit chip through wire bonding to lead out the signal of the piezoresistive sensitive chip 000.

[0068] Preferably, the first circuit chip 110 has at least one piezoresistive sensitive chip 000b for temperature compensation;

[0069] Optionally, each piezoresistive sensing chip 000 may correspond to one interconnection substrate 020 , or multiple piezoresistive sensing chips 000 may correspond to one interconnection substrate 020 to replace the first circuit sheet 110 ;

[0070] Optionally, two interconnect substrates are added under each piezoresistive sensing chip 000 to further reduce assembly stress;

[0071] Optionally, microchannels may be embedded inside the interconnect substrate for heat dissipation management;

[0072] Optionally, the interconnect substrate may be a ceramic sheet or a silicon transfer board or a glass substrate;

[0073] The back cavity of the piezoresistive sensitive chip 000 is evacuated, and the external gas pressure P1 is applied to the front resistance film 005 (not shown in the figure) of the piezoresistive sensitive chip 000 through the gas path system 200; the pressure difference between the two ends of the piezoresistive sensitive chip 000 is converted into an electrical signal proportional to the pressure change through the circuit system 100 and processed and calculated.

[0074] Optionally, the assembly system for pressure testing may refer to any one of those mentioned in Examples 1-3.

[0075] The rest is referred to Example 1.

[0076] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An array pressure measurement device, characterized in that: include: A piezoresistive sensitive chip, a reference pressure is applied to the front side of the chip, and an external gas pressure is applied to the back side to generate a pressure difference. A piezoresistive strip, a passivation layer and a pad are formed on the front side of the piezoresistive sensitive chip, and an open cavity is formed on the back side of the piezoresistive sensitive chip. A circuit system, integrated on the first circuit chip and the second circuit chip, the circuit system includes a temperature sensor chip, an instrument amplifier circuit, an ADC module and an MCU, and the circuit system is used to convert the pressure difference generated by the piezoresistive sensitive chip into an electrical signal output proportional to the pressure change and process and calculate; An air circuit system, used for providing air pressure and acting on both sides of the piezoresistive sensitive chip to generate the pressure difference, wherein the air circuit system is formed by sealingly connecting the back cavity of the piezoresistive sensitive chip, and the first alloy substrate, the second alloy substrate and the third alloy substrate; the first alloy substrate, the second alloy substrate and the third alloy substrate are provided with air guide holes penetrating the front and back sides and a reference pressure air circuit for setting a reference pressure; The first alloy substrate is provided with a boss structure, the piezoresistive sensitive chip is fixed on the boss structure of the first alloy substrate, the boss structure of the first alloy substrate is provided with an air guide hole, and the air guide hole is connected to the back cavity of the piezoresistive sensitive chip; An interconnection substrate with air guide holes is arranged between the piezoresistive sensing chip and the first alloy substrate boss; The temperature sensor chip is implemented by a piezoresistive sensitive chip.

2. An array pressure measurement device according to claim 1, characterized in that: The first alloy substrate is provided with an open cavity and a fixing structure for accommodating and fixing the first circuit chip and the second circuit chip.

3. An array pressure measurement device according to claim 2, characterized in that: An open cavity and a fixing structure are provided on the back of the first alloy substrate for placing the second alloy substrate and the third alloy substrate.

4. The array pressure measurement device according to claim 2, characterized in that: The second alloy substrate and the third alloy substrate are placed in the same open cavity on the side of the first alloy substrate, or are divided into two parts and placed on both sides of the first alloy substrate respectively.

5. The array pressure measurement device according to claim 2, characterized in that: The first circuit chip is placed in the open cavity on the front side of the first alloy substrate, and the second circuit chip is placed in the open cavity on the back side of the first alloy substrate; The second alloy substrate and the third alloy substrate are placed in an open cavity on the same side of the first alloy substrate, or can be divided into two parts and placed on two sides of the first alloy substrate respectively.

6. The array pressure measurement device according to claim 2, characterized in that: The first circuit chip is connected to the first alloy substrate with reference to the position of the piezoresistive sensitive chip, and the second circuit chip is connected to the step structure of the side wall of the first alloy substrate; stainless steel pipe air ports corresponding to the air guide holes are respectively arranged on the outer side of the third alloy substrate.

7. An array pressure measurement device according to any one of claims 1 to 6, characterized in that: The air guide holes are divided into a calibration passage, a test passage, and a temperature control passage; The second alloy substrate is movable, and the array pressure measurement device can be switched between the calibration passage and the test passage or between the temperature control passage and the test passage by moving the second alloy substrate; The array pressure measurement device also includes a device for driving the second alloy substrate to move. The device for driving the second alloy substrate to move is an electromagnet driver or a magnetostrictive driver arranged on the side wall of the first alloy substrate, or a convex shaft structure located on the second alloy substrate and connected to the outside of the package body, so as to realize the movement of the second alloy substrate.

8. The array pressure measurement device according to claim 1, characterized in that: After the open cavity on the back of the piezoresistive sensitive chip is evacuated, another piece of silicon or glass is bonded to the back of the piezoresistive sensitive chip to seal the open cavity, thereby forming an absolute pressure piezoresistive sensitive chip.

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