An array type pressure measurement device based on ceramic substrate

Abstract

The present invention discloses an array type pressure measuring device based on a ceramic substrate, comprising: 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 ceramic circuit chip, which is used to convert the pressure difference into an electrical signal proportional to the pressure change and output and process and calculate, wherein the ceramic circuit chip is provided with air guide holes, and the air guide holes penetrate the upper and lower surfaces of the ceramic circuit chip and are used to conduct air flow; an alloy substrate, wherein the alloy substrate comprises a first alloy substrate and a second alloy substrate, which is used to fix the ceramic circuit chip and is provided with air guide holes. The ceramic circuit chip integrated circuit interconnection structure of the present invention shortens the interconnection length, has excellent electrical and thermal properties, and is conducive to the miniaturization of the entire pressure measuring device assembly. In addition, the ceramic circuit chip has an integrated microchannel structure, which is helpful for the heat dissipation management of the assembly, and stably controls the temperature field where the circuit system is located to avoid device performance drift.

Description

Technical Field

[0001] The invention relates to the field of microelectronic packaging, and in particular to an array-type pressure measuring device based on a ceramic substrate. 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, the integration and assembly of multi-channel pressure test circuit systems are complex, the interconnection distance between the core chip-MEMS piezoresistive sensitive chip and the subsequent processing circuit is far, and the integration is low. In the representative technical solutions currently disclosed, the pressure gauge bare chip is assembled on the ceramic sheet-PCB circuit board-metal plate stack, and the bare chip input and output are gradually led out to the ceramic sheet through wire bonding, and then to the PCB circuit board, and finally handed over to the amplifier, digital-to-analog conversion and other modules assembled on the PCB board for signal processing, which limits the number of pressure measurement channels per unit area. Secondly, the stress and strain introduced during the assembly process of the MEMS piezoresistive sensitive chip device, the thermal stress caused by the difference in thermal expansion coefficient between it and other components of the device, and the uneven temperature distribution field, etc., lead to performance drift and difficult prediction, which restricts the long-term stability and comprehensive accuracy of the product. Finally, in the current technical solutions, the working temperature of the piezoresistive sensitive chip is generally obtained by a temperature sensor assembled on a circuit board or by using a temperature sensor integrated on the surface of the MEMS piezoresistive sensitive chip. Since the MEMS piezoresistive sensitive chip is in a material system with multiple thermodynamic properties and there is self-heating in its working state, this causes the temperature state of the piezoresistive sensitive strip to be difficult to test and characterize. The temperature sensor assembled on the circuit board cannot accurately characterize the temperature state of the piezoresistive sensitive strip of the piezoresistive sensitive chip in the working state, which limits the accuracy of temperature compensation. Summary of the invention

[0003] The object of the present invention is to provide an array-type pressure measurement device based on a ceramic substrate 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 measurement device based on a ceramic substrate, characterized in that it includes: 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 ceramic circuit chip, which is used to convert the pressure difference into an electrical signal output proportional to the pressure change and process and calculate, and the ceramic circuit chip is provided with air guide holes, and the air guide holes penetrate the upper and lower surfaces of the ceramic circuit chip and are used to conduct air flow; an alloy substrate, the alloy substrate includes a first alloy substrate and a second alloy substrate, which is used to fix the ceramic circuit chip and is provided with air guide holes; wherein: the piezoresistive sensitive chip includes a differential pressure piezoresistive sensitive chip and an absolute pressure piezoresistive sensitive chip; a piezoresistive strip, a passivation layer and a Pad are formed on the front side of the differential pressure piezoresistive sensitive chip, and an open cavity is formed on the back side of the piezoresistive sensitive chip; the absolute pressure piezoresistive sensitive chip is provided with a bonding silicon wafer on the back side on the basis of the differential pressure piezoresistive sensitive chip, which is used to seal the open cavity, and the sealed open cavity is a vacuum.

[0006] Preferably, a metal wiring layer is provided on the upper surface of the ceramic circuit chip, which is used to encapsulate a cavity for the piezoresistive sensitive chip and a pad for wire bonding or flip-chip bonding.

[0007] Preferably, a flow guiding structure and a microchannel are provided inside the ceramic circuit chip.

[0008] Preferably, the microchannel is provided with a first inlet and a first outlet on the lower surface of the ceramic circuit sheet, respectively, and the microchannel structure is used to pass a cooling medium to cool the circuit.

[0009] Preferably, a piezoresistive sensitive chip array is arranged on the ceramic circuit chip, and the number of the piezoresistive sensitive chip array can be adjusted according to demand.

[0010] Preferably, at least one piezoresistive sensitive chip is also provided on the ceramic circuit chip, which is used to accurately extract the temperature of the piezoresistive resistor strip of the piezoresistive sensitive chip in real time for temperature compensation.

[0011] Preferably, the first alloy substrate has air guide holes penetrating the front and back sides and a reference pressure air path for setting a reference pressure.

[0012] Preferably, the first alloy substrate is further provided with a second input flow channel and a second output flow channel for system cooling, which are respectively connected to the first inlet and the first outlet of the microchannel.

[0013] Preferably, the device is further provided with a valve assembly integrated at the bottom of the first alloy substrate.

[0014] Preferably, a sealing ring is provided between the alloy substrate and the valve assembly, and the alloy substrate and the valve assembly are connected by threads or by using a sealant.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) Based on the direct integrated circuit interconnection structure of ceramic circuit chips, no additional integrated PCB circuit board is required, the interconnection length can be shortened, and it has excellent electrical and thermal properties, which is conducive to the miniaturization of the entire pressure measurement device assembly.

[0017] (2) The microfluidic structure integrated inside the ceramic circuit chip helps to manage the heat dissipation of the assembly, accurately control the temperature field of the piezoresistive sensitive chip or circuit system, maintain the long-term stability and overall accuracy of the product, and avoid device performance drift.

[0018] (3) Temperature compensation uses the same MEMS piezoresistive sensitive chip in the insensitive measurement gas as used for pressure measurement to extract the temperature of the piezoresistive sensitive strip in the working state, which can improve the temperature compensation accuracy.

[0019] (4) The piezoresistive sensitive chip, ceramic circuit chip and alloy substrate are bonded with packaging glue, which can effectively reduce assembly stress.

[0020] (5) 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of Example 1 of the present invention.

[0022] Figure 2 Schematic diagram of a differential pressure piezoresistive sensing chip according to Example 1 of the present invention.

[0023] Figure 3 This is a schematic diagram of an absolute pressure piezoresistive sensing chip according to Example 1 of the present invention.

[0024] Figure 4 This is a schematic diagram of a piezoresistive sensitive chip for temperature compensation according to Example 1 of the present invention.

[0025] Figure 5 for Figure 4 Schematic diagram of the cross-section at a-a'.

[0026] Figure 6 Schematic diagram of a top view of a ceramic circuit sheet according to Embodiment 1 of the present invention.

[0027] Figure 7 Schematic diagram of a ceramic circuit chip circuit according to Embodiment 1 of the present invention.

[0028] Figure 8 Schematic diagram of the cross section of the ceramic circuit sheet according to Example 1 of the present invention.

[0029] Fig. 9 This is a schematic diagram of the first alloy substrate of Example 1 of the present invention.

[0030] Fig.10 Schematic diagram of the front and side surfaces of the second alloy substrate of Example 1 of the present invention.

[0031] Fig.11 This is a schematic diagram of the back side of the second alloy substrate of Example 1 of the present invention.

[0032] Fig.12 Schematic diagram of the front and side views of the third alloy substrate of Example 1 of the present invention.

[0033] Fig.13 This is a schematic diagram of the structure of Example 2 of the present invention.

[0034] Fig.14 This is a schematic diagram of the structure of Example 3 of the present invention.

[0035] Fig.15 This is a schematic diagram of the structure of Example 4 of the present invention. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] 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.

[0039] See also Figure 1-12 , the present invention provides a technical solution:

[0040] Array pressure measurement device based on ceramic substrate and integrated assembly method Figure 1 As shown, the pressure measuring device mainly includes: a piezoresistive sensitive chip 000 , a ceramic circuit sheet 100 and an alloy substrate 200 .

[0041] refer to Figure 2-3 In one embodiment of the present invention, the piezoresistive sensing chip 000 can be further divided into a differential pressure piezoresistive sensing chip 000a and an absolute pressure piezoresistive sensing chip 000b.

[0042] The differential pressure piezoresistive sensing chip 000a is a silicon substrate, and a piezoresistive strip 001, a passivation layer 002 and a pad 003 are formed on the front of the piezoresistive sensing chip 000 by epitaxy, oxidation, diffusion, sputtering and other processes; and a back cavity 004 is formed on the back of the piezoresistive sensing chip 000 by etching. The air pressure on both sides of the differential pressure piezoresistive sensing chip 000a is adjustable.

[0043] Under working conditions, a reference pressure P1 is applied to the front side of the differential pressure piezoresistive sensitive chip 000a, and the external gas pressure P2 is applied to the back side of the differential pressure piezoresistive sensitive chip 000a through the gas guide channel to form a back side cavity 004; the pressure difference between the two ends of the differential pressure piezoresistive sensitive chip 000a is converted into an electrical signal proportional to the pressure change through the circuit and processed and calculated.

[0044] The absolute pressure piezoresistive sensing chip 000b is based on the differential pressure piezoresistive sensing chip 000a. After the back cavity 004 is evacuated, another silicon wafer 010 is bonded to the back of the differential pressure piezoresistive sensing chip 000a to seal the open cavity 214, thereby forming the absolute pressure piezoresistive sensing chip 000b. The pad 003 includes at least one power pad, one ground pad, and two signal pads. The air pressure in the back cavity 004 of the absolute pressure piezoresistive sensing chip 000b is zero and cannot be adjusted.

[0045] refer to Figure 6-8 In one embodiment of the present invention, the upper surface of the ceramic circuit sheet 100 is provided with a cavity 101 for packaging the piezoresistive sensing chip 000, and the upper surface is provided with a metal wiring layer 102 (refer to Figure 1), and a pad 103 for wire bonding or flip-chip bonding; a temperature sensor chip 130, an instrument amplifier circuit 131, an ADC module 132, an MCU 133, and other modules are integrated at the pad 103 by wire bonding or mounting. The signal generated by the pressure difference of the piezoresistive sensitive chip 000 is amplified by the instrument amplifier circuit and enters the ADC module module, then enters the MCU processing unit, and finally enters the visual interface processing.

[0046] In one embodiment of the present invention, the ceramic circuit sheet 100 is provided with air-conducting holes 104 therein. The air-conducting holes 104 penetrate the upper and lower surfaces of the ceramic circuit sheet 100 and are used to conduct air flow.

[0047] In one embodiment of the present invention, a flow guide structure 105 and a microchannel 106 are provided in the body of the ceramic circuit chip 100. The microchannel 106 is provided with a first inlet 106a and a first outlet 106b on the lower surface of the ceramic circuit chip 100, respectively. The microchannel structure is used to pass a cooling medium to cool the circuit. In one embodiment of the present invention, the cooling medium can be deionized water, 3M HFE-7100, etc.;

[0048] The flow guide structure 105 is used to evenly distribute the cooling medium to the microchannel 106, reduce the pressure difference between the inlet and outlet of the microchannel, and reduce the power loss of the pump. The microchannel 106 is provided with a boss 107 to wrap the air guide holes 104 in the ceramic circuit chip 100, so that the cooling system is isolated from the gas path system. The microchannel 106 is also provided with different flow channel configurations 108, and the flow channel configuration 108 can be parallel straight lines, rectangles, cylinders, S shapes, etc., to enhance the heat dissipation effect. The cooling medium flows between the boss 107 and the flow channel configuration.

[0049] refer to Figure 4-5 In one embodiment of the present invention, a 4x8 array of piezoresistive sensing chips 000 is integrated on the ceramic circuit sheet 100. In other embodiments, the number of piezoresistive sensing chips 000 can be further expanded according to actual application requirements, and more test channels can be added.

[0050] Optionally, the ceramic circuit chip 100 may also integrate a temperature sensor chip 130 for real-time detection of the temperature of the piezoresistive sensitive chip 000. Preferably, at least one piezoresistive sensitive chip 000c is also provided in the piezoresistive sensitive chip array integrated in the ceramic circuit chip 100 for real-time and accurate extraction of the temperature of the piezoresistive sensitive chip piezoresistive resistor strip for temperature compensation. Figure 4The piezoresistive sensitive chip 000c is integrated in the cavity 101 of the ceramic circuit chip 100. The cavity 101 is provided with a gas channel, one end of which is connected to the back cavity 004 of the piezoresistive sensitive chip 000c, and the other end is connected to the working cavity of the piezoresistive sensitive chip 000c, that is, the cavity 101 on the surface of the ceramic circuit chip 100. The pressure difference on both sides of the membrane surface of the piezoresistive sensitive chip is set to zero, so that the piezoresistive sensitive chip 000c always maintains a zero-point output state. The working voltage conditions of 000c and other piezoresistive sensitive chips 000 are consistent, and they work at the same time. When the temperature of the environment 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 000c piezoresistive strip can be extracted by testing for evaluation and characterization, which is used for device temperature compensation and can greatly improve the temperature measurement accuracy used for temperature compensation.

[0051] In one embodiment of the present invention, the ceramic circuit chip is made of LTCC substrate, or other ceramic materials such as HTCC and aluminum nitride.

[0052] refer to Figure 9-12 In one embodiment of the present invention, the alloy substrate 200 can be further divided into a first alloy substrate 210 and a second alloy substrate 220. The first alloy substrate 210 has an air guide channel 211 running through the front and back sides and a reference pressure air path 212 for setting a reference pressure. The air guide channel 211 corresponds one-to-one to the back cavity 004 of the piezoresistive sensing chip 000, and the reference pressure air path 212 is used to set a reference pressure.

[0053] In one embodiment of the present invention, the first alloy substrate 210 is further provided with a second input channel 213a and a second output channel 213b for system cooling, which are respectively connected to the first inlet 106a and the first outlet 106b of the microchannel 106; the front of the first alloy substrate 210 is provided with an open cavity 214 for accommodating the ceramic circuit chip 100; the side of the open cavity 214 is provided with a step structure 215 for bonding the second alloy substrate 220 to seal the open cavity 214, and the bonding method can be sealing adhesive or threading, etc., to facilitate subsequent disassembly and maintenance of the piezoresistive sensitive chip or circuit chip. In one embodiment of the present invention, the step structure 215 has a groove for placing a sealing ring to ensure the airtightness inside the open cavity 214.

[0054] In one embodiment of the present invention, the device is further provided with a valve assembly, which is integrated at the bottom of the first alloy substrate 210, and the device further includes a third alloy substrate 230 and a fourth alloy substrate 240. The third alloy substrate 230 has an air-conducting hole 231 that runs through the front and back sides and a reference pressure air path 232 for setting a reference pressure; wherein the air-conducting hole 231 is divided into a calibration passage 231a, a test passage 231b, and a temperature control passage 231c, and the calibration passage 231a and the temperature control passage 231c are combined into a first passage. The third alloy substrate 230 is also provided with a third input flow channel 233a and a third output flow channel 233b in the body, which are respectively connected to the second input flow channel 213a and the second output flow channel 213b.

[0055] In one embodiment of the present invention, the fourth alloy substrate 240 has air guide holes 241 running through the front and back sides and a reference pressure air path 242 for setting the reference pressure; the fourth alloy substrate 240 also has a fourth input channel 243a and a fourth output channel 243b in the body thereof, which are connected to the third input channel 233a and the third output channel 233b, respectively. In one embodiment of the present invention, the fourth alloy substrate 240 also has a calibration conversion channel inlet 244 and a temperature control conversion channel inlet 245 on the back side thereof.

[0056] In one embodiment of the present invention, the third alloy substrate 230 is movable, and can switch between the calibration passage 231a or the temperature control passage 231c and the test passage 231b by manually turning the convex shaft structure 234 located on the third alloy substrate 230 and connected to the outside of the package body; a sealing ring 201 is provided between the alloy substrates to ensure the sealing of the gas path system; the valve assembly is connected to the bottom of the first alloy substrate 210 by bolts, and a sealing gasket is used to ensure the sealing of the gas path system.

[0057] Stainless steel pipe gas ports 246 corresponding to the gas guide holes or functional modules are respectively arranged on the outside of the fourth alloy substrate 240, and a hose 247 can be also sheathed over the stainless steel pipe gas ports 246 to facilitate connection with external components to be tested or operating devices.

[0058] The alloy substrate 200 and the valve assembly are supplemented with a sealing ring, and are interconnected by threaded connection or using sealant; the valve assembly can be placed at the bottom of the alloy substrate 200 or at the side of the alloy substrate 200, and the gas path or cooling system channel path needs to be adjusted accordingly.

[0059] In the calibration mode, external air enters from the calibration conversion channel inlet 244 of the fourth alloy substrate 240, passes through the air guide holes 231, enters the calibration passage 221a of the third alloy substrate 230, and then enters the air guide channel 211 of the first alloy substrate 210, and finally passes through the air guide holes 104 of the ceramic circuit sheet 100 to enter the back cavity 004 of the piezoresistive sensitive chip 000 attached to the upper part of the ceramic circuit sheet 100.

[0060] In the test mode, external air enters through the multiple air holes 241 of the fourth alloy substrate 240, passes through the test passage 231b of the third alloy substrate 230, enters the air channel 211 of the first alloy substrate 210, and finally passes through the air holes 104 of the ceramic circuit sheet 100 into the back cavity 004 of the piezoresistive sensitive chip 000 attached to the upper part of the ceramic circuit sheet 100. Each piezoresistive sensitive chip 000 can be measured individually.

[0061] In the temperature control mode, the external gas enters from the temperature control conversion channel inlet 245 of the fourth alloy substrate 240, passes through the gas-conducting holes 231, enters the temperature control passage 231c of the third alloy substrate 230, and then enters the gas-conducting channel 211 of the first alloy substrate 210, and finally passes through the gas-conducting holes 104 of the ceramic circuit sheet 100 to enter the back cavity 004 of the piezoresistive sensitive chip 000 attached to the upper part of the ceramic circuit sheet 100; the external gas can be selected as a cooling medium such as nitrogen or helium, and the test device described in the present invention can realize the simultaneous opening of the temperature control mode under the test mode.

[0062] In the reference pressure setting mode, the external gas enters from the reference pressure gas path 242 of the fourth alloy substrate 240, passes through the reference pressure gas path 242 of the second alloy substrate, enters the reference pressure gas path 212 of the first alloy substrate, and finally enters the open cavity 214 of the first alloy substrate 210 where the piezoresistive sensitive chip 000 is located, completing the reference pressure setting of the piezoresistive sensitive chip;

[0063] In the microchannel heat dissipation mode, the cooling medium enters from the fourth input channel 243a of the fourth alloy substrate 240, passes through the third input channel 233a and the second input channel 213a in sequence, and then enters the microchannel 106 from the first inlet 106a through the guide structure 105, flows in the horizontal direction, and then flows from the guide structure 105 through the first outlet 106b to the second output channel 213b, the third output channel 233b, and flows out from the fourth output channel 243b, forming a connected microchannel system.

[0064] Example 2

[0065] refer to Fig.13The difference between this embodiment and the first embodiment is that the piezoresistive sensitive chip 000 is wire-bonded in the cavity 101 on the upper surface of the ceramic circuit sheet 100, and the remaining circuit systems such as the pins 134, the temperature sensor chip 130, the instrument amplifier circuit 131, the ADC module 132, the MCU 133 and other modules are mounted on the second ceramic circuit sheet 110. The second ceramic circuit sheet 110 is bonded on the first alloy substrate 210; the back of the second ceramic circuit sheet 110 is provided with an open large cavity 111 sufficient to accommodate the wire bonding space of the piezoresistive sensitive chip 000; the upper surface of the second ceramic circuit sheet is provided with a metal wiring layer 112 and a pad 113; the body is provided with an interconnection structure 114 extending in the thickness direction, which is used to connect the circuit elements respectively placed on the ceramic circuit sheet 100 and the second ceramic circuit sheet 110.

[0066] Pins are provided on the upper surface of the ceramic circuit sheet 100 and the lower surface of the second ceramic circuit sheet 110 for bonding the two. Optionally, large solder balls may be implanted on the upper surface of the ceramic circuit sheet 100 and the lower surface of the second ceramic circuit sheet 110 for interconnection to reduce parasitic effects of the circuit system. Optionally, the ceramic circuit sheet 100 and the second ceramic circuit sheet 110 may be directly bonded.

[0067] Example 3

[0068] refer to Fig.14 The difference between this embodiment and embodiment 2 is that a small cavity 111a corresponding to the piezoresistive sensitive chip 000 is provided on the back of the second ceramic circuit sheet 110, which is large enough to accommodate the space for wire bonding of the piezoresistive sensitive chip 000; an array of small solder balls 140c are implanted on the upper surface of the ceramic circuit sheet 100 and the lower surface of the second ceramic circuit sheet 110 for bonding the two; compared with the large cavity 101 on the upper surface of the ceramic circuit sheet 100 in embodiment 2, this embodiment is conducive to increasing the bonding area of ​​the ceramic circuit sheet 100 and the second ceramic circuit sheet 110, and improving the mechanical strength.

[0069] Example 4

[0070] refer to Fig.15 The difference between this embodiment and embodiment 3 is that a small cavity 111a corresponding to the piezoresistive sensitive chip 000 is provided on the back of the second ceramic circuit sheet 110, and a solder ball 111b is implanted in the small cavity 111a and bonded to the Pad 003 of the piezoresistive sensitive chip 000 in a one-to-one manner; a sealing gasket is added between the piezoresistive sensitive chip 000 and the ceramic circuit sheet 100, and then the ceramic circuit sheet 100 is bonded to the second ceramic circuit sheet through the solder ball; this embodiment has a more precise requirement on the cavity height between the ceramic circuit sheet and the second ceramic circuit sheet, and adopts the method of solder ball interconnection instead of wire bonding, which is beneficial to reducing circuit parasitic effects, improving electrical and thermal properties, and further reducing the package size.

[0071] The present invention effectively reduces assembly stress by bonding the piezoresistive sensitive chip, the ceramic circuit chip and the alloy substrate with packaging glue, such as thermal conductive silicone, epoxy resin glue, Dow Corning's 3145 RTV packaging glue, etc.

[0072] The ceramic circuit chip integrated circuit interconnection structure does not require additional integrated PCB circuit boards, and is integrated by solder balls, which shortens the interconnection length and has excellent electrical and thermal properties, which is conducive to the miniaturization of the entire pressure measurement device assembly. The present invention integrates a microfluidic structure inside the ceramic circuit chip, which helps to manage the heat dissipation of the assembly, stably controls the temperature field where the piezoresistive sensitive chip or circuit system is located, maintains the long-term stability and comprehensive accuracy of the product, and avoids device performance drift. The pressure measurement device of the present invention has chip-level maintainability, and multiple circuit chips are stacked and integrated, which is convenient for disassembly and individual replacement of piezoresistive sensitive chips or related circuit system components, and the gas path system can also be disassembled for cleaning and maintenance.

[0073] 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 based on a ceramic substrate, characterized in that: include: Piezoresistive sensitive chip, a reference pressure is applied to the front of the piezoresistive sensitive chip, and external gas pressure is applied to the back to generate a pressure difference; A ceramic circuit chip, used to convert the pressure difference into an electrical signal proportional to the pressure change and process and calculate it, wherein the ceramic circuit chip is provided with air guide holes, which penetrate the upper and lower surfaces of the ceramic circuit chip and are used to conduct air flow; An alloy substrate, comprising a first alloy substrate and a second alloy substrate, used for fixing the ceramic circuit sheet and provided with air guide holes; Wherein: the piezoresistive sensing chip includes a differential pressure piezoresistive sensing chip and an absolute pressure piezoresistive sensing chip, the front side of the differential pressure piezoresistive sensing chip forms a piezoresistive strip, a passivation layer and a Pad, and the back side of the piezoresistive sensing chip forms an open cavity; the back side of the absolute pressure piezoresistive sensing chip is provided with a bonding silicon wafer on the basis of the differential pressure piezoresistive sensing chip, which is used to seal the open cavity, and the sealed open cavity is a vacuum; The first alloy substrate has air guide holes penetrating the front and back sides and a reference pressure air path for setting a reference pressure; The first alloy substrate is also provided with a second input flow channel and a second output flow channel for system cooling, which are respectively connected to the first inlet and the first outlet of the microchannel.

2. The measuring device according to claim 1, characterized in that The upper surface of the ceramic circuit chip is provided with a metal wiring layer, a cavity for encapsulating a piezoresistive sensitive chip, and a pad for wire bonding or flip-chip bonding.

3. The measuring device according to claim 1, characterized in that The ceramic circuit sheet is provided with a flow guiding structure and a micro-channel.

4. The measuring device according to claim 3, characterized in that The microchannel is provided with a first inlet and a first outlet on the lower surface of the ceramic circuit sheet, respectively. The microchannel structure is used to pass a cooling medium to cool the circuit.

5. The measuring device according to claim 1, characterized in that A piezoresistive sensitive chip array is arranged on the ceramic circuit chip, and the number of the piezoresistive sensitive chip array is adjusted according to demand.

6. The measuring device according to claim 5, characterized in that The ceramic circuit chip is also provided with at least one piezoresistive sensitive chip for accurately extracting the temperature of the piezoresistive resistor strip of the piezoresistive sensitive chip in real time for temperature compensation.

7. The measuring device according to claim 1, characterized in that The device is also provided with a valve assembly integrated at the bottom of the first alloy substrate.

8. The measuring device according to claim 7, characterized in that A sealing ring is arranged between the alloy substrate and the valve assembly, and the alloy substrate and the valve assembly are connected by threads or by using sealing adhesive.

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