CN112880902A - Array type pressure measuring device - Google Patents
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- CN112880902A CN112880902A CN202110343741.XA CN202110343741A CN112880902A CN 112880902 A CN112880902 A CN 112880902A CN 202110343741 A CN202110343741 A CN 202110343741A CN 112880902 A CN112880902 A CN 112880902A
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- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/02—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in ohmic resistance, e.g. of potentiometers, electric circuits therefor, e.g. bridges, amplifiers or signal conditioning
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Abstract
The invention discloses an array type pressure measuring device, comprising: the piezoresistive sensitive chip is used for applying reference pressure on the front surface of the piezoresistive sensitive chip and applying external gas pressure on the back surface of the piezoresistive sensitive chip to generate pressure difference; the circuit system is used for converting the generated pressure difference into an electric signal which is proportional to the pressure change, outputting the electric signal and processing and calculating the electric signal; and the air path system is used for providing air pressure and acting on two sides of the piezoresistive sensitive chip to generate the pressure difference. According to the piezoresistive pressure measuring device, the alloy substrate and the piezoresistive sensitive chip are directly bonded by adopting the packaging sealant, the PCB is positioned on two sides of the piezoresistive sensitive chip and is electrically interconnected, the assembly stress can be reduced, a support is provided for the accurate control of the stress and temperature state of the piezoresistive sensitive chip, the piezoresistive sensitive chip or related circuit system components are convenient to disassemble and replace independently, the multilayer circuit chips are stacked and integrated, and the internal integrated gas circuit system is favorable for the miniaturization of the whole pressure measuring device assembly body.
Description
Technical Field
The invention relates to the field of microelectronic packaging, in particular to an array type pressure measuring device.
Background
The array type multi-channel pressure measuring device is widely applied to wind tunnel tests or flight tests, and can realize multi-channel rapid pressure measurement, wherein the MEMS piezoresistive sensitive chip is a core device of the pressure measuring device and has decisive influence on the overall performance of the pressure measuring device. The improvement of the comprehensive performance of the conventional array type multichannel pressure measuring device faces some core problems to be solved and optimized. Firstly, stress strain is introduced in the assembly process of the device, and the performance of the piezoresistive sensitive chip is influenced. Because the piezoresistive sensitive chip and other parts of the device have different thermal expansion coefficients, the piezoresistive sensitive chip and the external environment form a complex heat conduction path in the working state, the chip generates heat and the environment temperature field of the device enables the temperature state of the piezoresistive sensitive chip to change, the thermal stress strain also changes, the factors cause performance drift and are difficult to accurately predict, and the long-term stability and the comprehensive precision of the product are restricted. The difficult problem is solved by a subsequent circuit system compensation method, wherein the stress generated in the assembly process needs to be controlled, and the stress and temperature distribution state of a chip in the working process needs to be accurately controlled or the state change of the chip is accurately acquired. In the currently disclosed representative technical scheme, a pressure gauge chip is assembled on a ceramic chip-PCB (printed Circuit Board) -metal plate lamination layer, a bonding material is used for solving the stress strain problem in the assembling process and the stress problem caused by mismatch of thermal expansion coefficients, and the working state temperature of a piezoresistive sensitive chip is obtained through a temperature sensor assembled on a circuit board; however, the ceramic chip-PCB lamination has complex thermodynamic characteristics, and the temperature sensor assembled on the circuit board cannot accurately represent the temperature state of the piezoresistive sensitive chip in a working state, especially the temperature state of the piezoresistive sensitive strip, which limits the temperature compensation precision. In addition, another problem with the current devices is that chip-level maintenance is difficult, and it is often impossible to disassemble and maintain, replace, etc. a single chip in a pressure measurement device.
Disclosure of Invention
The present invention is directed to an array pressure measuring device to solve the above problems.
In order to achieve the purpose, the invention provides the following technical scheme:
an array pressure measurement device comprising:
the piezoresistive sensitive chip is used for applying reference pressure on the front surface of the piezoresistive sensitive chip and applying external gas pressure on the back surface of the piezoresistive sensitive chip to generate pressure difference, a piezoresistive strip, a passivation layer and a Pad are formed on the front surface of the piezoresistive sensitive chip, and an open cavity is formed on the back surface of the piezoresistive sensitive chip; the circuit system is integrated on the first circuit chip and the second circuit chip, comprises a temperature sensor chip, an instrument amplifying circuit, an ADC module and an MCU, and is used for converting the pressure difference generated by the piezoresistive sensitive chip into an electric signal which is in direct proportion to the pressure change, outputting the electric signal and processing and calculating the electric signal; the gas path system is used for providing gas pressure and acting on two sides of the piezoresistive sensitive chip to generate the pressure difference, and is formed by hermetically connecting a cavity on the back of the piezoresistive sensitive chip, a first alloy substrate, a second alloy substrate and a third alloy substrate; the first alloy substrate, the second alloy substrate and the third alloy substrate are provided with air guide holes penetrating through the front surface and the back surface and a reference pressure air path for setting 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 an air guide hole and connected with a cavity on the back of the piezoresistive sensitive chip.
Furthermore, the first alloy substrate is provided with an open cavity and a fixing structure for accommodating and fixing the first circuit piece and the second circuit piece.
Furthermore, an open cavity and a fixing structure are arranged on the back of the first alloy substrate and used for placing the second alloy substrate and the third alloy substrate.
Furthermore, the second alloy substrate and the third alloy substrate are arranged in the same side open cavity of the first alloy substrate, or divided into two parts which are respectively arranged at two sides of the first alloy substrate.
Further, the first circuit piece is arranged in the open cavity on the front surface of the first alloy substrate, and the second circuit piece is arranged in the open cavity on the back surface of the first alloy substrate; the second alloy substrate and the third alloy substrate are arranged in an air cavity opened on the same side face of the first alloy substrate, or can be divided into two parts which are respectively arranged on two sides of the first alloy substrate.
Furthermore, the first circuit piece is connected to the first alloy substrate according to the mounting position of the piezoresistive sensitive chip, and the second circuit piece is connected to the side wall step structure of the first alloy substrate; and stainless steel pipe air ports corresponding to the air guide holes are respectively arranged on the outer sides of the third alloy substrates.
Further, 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 type pressure measuring device can be switched between a calibration passage or a temperature control passage and a test passage by moving the second alloy substrate;
the array pressure measuring device further comprises a device for driving the second alloy substrate to move, wherein the device is an electromagnet driver or a magnetostrictive driver arranged on the side wall of the first alloy substrate, or a protruding shaft structure which is positioned on the second alloy substrate and connected to the outer side of the packaging body, so that the second alloy substrate can move.
Furthermore, the temperature sensor chip is realized by adopting the piezoresistive sensitive chip.
Furthermore, after the open cavity at the back of the piezoresistive sensitive chip is vacuumized, another piece of silicon or glass is bonded to the back of the piezoresistive sensitive chip to seal the open cavity, so that the absolute pressure type piezoresistive sensitive chip is formed.
Furthermore, an interconnection substrate with air holes is arranged between the piezoresistive sensitive chip and the first alloy substrate boss.
Compared with the prior art, the invention has the beneficial effects that:
(1) the alloy substrate and the piezoresistive sensitive chip are directly bonded by adopting packaging glue, and the PCB is positioned at two sides of the piezoresistive sensitive chip for electrical interconnection, so that the assembly stress can be reduced; meanwhile, the alloy substrate is used as a heat sink and is directly connected with the piezoresistive sensitive chip, the thermodynamic property between the alloy substrate and the piezoresistive sensitive chip is simple, the temperature distribution of the pressure chip in a working state can be accurately calculated only by a temperature sensor assembled on the circuit board, the thermal stress is easy to accurately control, and the heat dissipation management is facilitated; in addition, a cooling channel is arranged in the alloy to control the temperature of the array type piezoresistive sensitive chip, so that long-term stability and comprehensive precision are maintained, and performance drift of the device is avoided.
(2) The pressure measuring device has chip-level maintainability, multiple circuit chips are stacked and integrated, the pressure measuring device is convenient to disassemble and can replace a piezoresistive sensitive chip or related circuit system components independently, and the gas circuit system can be disassembled to be cleaned and maintained.
(3) The first alloy substrate is provided with a multi-surface cavity, the array type piezoresistive sensitive chip and the circuit system are placed, and the internal integrated gas circuit system is favorable for miniaturization of the whole pressure measuring device assembly body.
Drawings
Fig. 1 is a schematic structural diagram of embodiment 1 of the present invention.
Fig. 2 is a schematic diagram of a differential pressure type piezoresistive sensitive chip in embodiment 1 of the invention.
Fig. 3 is a schematic diagram of a piezoresistive sensitive chip for temperature compensation in embodiment 1 of the present invention.
FIG. 4 is a schematic sectional view taken at a-a' in FIG. 3.
FIG. 5 is a diagram illustrating the integration of the first chip according to the present invention.
FIG. 6 is a second integrated circuit chip of the present invention.
FIG. 7 is a schematic view of a first alloy substrate according to the present invention.
FIG. 8 is a schematic sectional view at b-b' of FIG. 7.
FIG. 9 is a schematic view of a second alloy substrate according to the present invention.
FIG. 10 is a schematic cross-sectional view at c-c' of FIG. 9.
Fig. 11 is a back view of fig. 9.
FIG. 12 is a schematic view of a third alloy substrate according to the present invention.
FIG. 13 is a schematic sectional view taken at d-d' of FIG. 12.
Fig. 14 is a schematic structural diagram of embodiment 2 of the present invention.
Fig. 15 is another schematic structural diagram of embodiment 2 of the present invention.
Fig. 16 is a schematic structural diagram of embodiment 3 of the present invention.
Fig. 17 is a schematic structural diagram of embodiment 4 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "upper/lower end", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be configured in a specific orientation, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed/sleeved," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Referring to fig. 1-13, the present invention provides a technical solution:
the array type pressure measuring device and the integrated assembly method are shown in fig. 1, and the pressure measuring device mainly comprises a piezoresistive sensitive chip 000, a circuit system 100 and an air path system 200.
Referring to fig. 2-4, the piezoresistive sensitive chip 000 is a silicon substrate, and a piezoresistive strip 001, a passivation layer 002 and Pad 003 are formed on the front surface of the piezoresistive sensitive chip 000 through processes such as epitaxy, oxidation, diffusion, sputtering and the like; an etching process is adopted to form an open cavity 004 on the back surface of the piezoresistive sensitive chip 000. Wherein Pad 004 includes at least 1 power Pad, 1 ground Pad, and 2 signal pads. Applying a reference pressure P1 on the front surface of the piezoresistive sensitive chip 000, and applying an external gas pressure P2 to the back open cavity 004 of the piezoresistive sensitive chip 000 through the gas circuit 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 the electrical signal is output, processed and calculated.
In an embodiment of the invention, the piezoresistive sensitive chip further includes an absolute pressure type piezoresistive sensitive chip, and the absolute pressure type piezoresistive sensitive chip is formed by bonding another silicon sheet to the back surface of the piezoresistive sensitive chip after the back surface open cavity is vacuumized on the basis of the piezoresistive sensitive chip 000a to seal the open cavity. The air pressure in the open cavity on the back of the pressure-insulating piezoresistive sensitive chip is zero and cannot be adjusted.
Referring to fig. 5-6, the circuit system 100 includes a piezoresistive sensitive chip 000, a temperature sensor chip 101, an instrument amplifier circuit 102, an ADC 103 module, an MCU104, and the like; integrating a piezoresistive sensitive chip 000 and a temperature sensor chip 101 on a first circuit chip 110 in a lead bonding manner, and integrating an instrument amplification circuit 102, an ADC 103 module, an MCU104 and the like on a second circuit chip 120 in a routing or mounting manner; the first die 110 is placed in parallel with the second die 120 in a stack, which are interconnected by a flexible line or pin header 105; signals generated by the piezoresistive sensitive chip 000 due to pressure difference are amplified by the instrument amplifying circuit, enter the ADC module, then enter the MCU processing unit, and finally enter the visual interface for processing and calculation.
In this embodiment, the piezoresistive sensitive chips 000a in the 4 × 8 array are integrated on the first circuit chip 110, so that the number of the piezoresistive sensitive chips 000a can be further expanded according to the requirement, and more channels can be added; optionally, the first circuit piece 110 may further integrate a temperature sensor chip 101 for detecting the temperature of the piezoresistive sensitive chip 000 in real time;
preferably, the temperature sensor 101 is implemented by using a piezoresistive sensitive chip 000b, referring to fig. 3, when implemented by using the piezoresistive sensitive chip, the piezoresistive sensitive chip 000b is directly bonded to a boss 217 of the first alloy substrate 210 by using a packaging adhesive, the boss 217 is provided with a gas channel, one end of the gas channel is communicated to a back cavity 004 of the piezoresistive sensitive chip 000b, and the other end of the gas channel is communicated to a cavity in which the piezoresistive sensitive chip 000b works, namely the cavity 213 is opened on the front surface of the first alloy substrate 210, and the pressure difference between two sides of the membrane surface of the piezoresistive sensitive chip is set to be zero, so that deformation is not generated, the piezoresistive sensitive chip 000b always keeps a zero output state, and the change of the resistance only reflects the temperature change; 000b is consistent with the working voltage conditions of other piezoresistive sensitive chips 000, and works simultaneously, when the temperature of the environment where the piezoresistive sensitive chip 000a is located changes and the temperature changes are caused by the thermoelectric effect of the piezoresistive strips 001 on the surface of the piezoresistive sensitive chip 000, the resistance change quantity of the piezoresistive strips 000b can be extracted through testing to carry out evaluation and characterization, so that the piezoresistive strip resistance change quantity can be used for device temperature compensation, and the temperature measurement accuracy for the temperature compensation can be improved.
In one embodiment of the present invention, the height of the bump 217 is determined according to the difference between the thickness of the first die 110 and the thickness of the piezoresistive sensor die 000, so that the height difference between the front surface of the piezoresistive sensor die 000 and the upper surface of the first die 110 is less than 200 μm.
Referring to fig. 7-13, the gas circuit system 200 is formed by sequentially sealing and connecting a cavity 004 at the back of the piezoresistive sensitive chip, a first alloy substrate 210 with gas vents, a second alloy substrate 220 and a third alloy substrate 230; wherein the first alloy substrate 210 is provided with an air guide hole 211 penetrating through the front surface and the back surface and a reference pressure air path 212 for setting reference pressure; the second alloy substrate 220 is provided with an air guide hole 221 penetrating through the front surface and the back surface and a reference pressure air path 222 for setting reference pressure; wherein the air vent 221 is divided into a calibration passage 221a, a test passage 221b, and a temperature control passage 221c, and the calibration passage 221a and the temperature control passage 221c are combined into a first passage; the third alloy substrate 230 has an air guide hole 231 penetrating the front and back surfaces and a reference pressure air passage 232 for setting a reference pressure; in addition, a calibration via inlet 233 and a temperature control via inlet 234 are provided on the back surface of the third alloy substrate 230. The second alloy substrate 220 has mobility, and can be switched between the calibration via 221a or the temperature control via 221c and the test via 221b by the movement; and a sealing ring 201 is arranged between the alloy substrates to ensure the tightness of the gas path system.
In the calibration mode, the external gas enters from the calibration conversion channel inlet 233 of the third alloy substrate 230, passes through the gas guide hole 231, enters the calibration passage 221a of the second alloy substrate 220, enters the gas 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 portion of the first alloy substrate 210.
In the test mode, the external air enters from the plurality of air holes 231 of the third alloy substrate 230, passes through the test passages 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 chips 000 attached to the upper portion of the first alloy substrate 210, and each piezoresistive sensitive chip 000 can be measured independently.
In the temperature control mode, external air enters from the inlet 234 of the temperature control conversion channel of the third alloy substrate 230, enters the temperature control passage 221c of the second alloy substrate 220 through the air guide port 231, 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 from nitrogen or helium and other cooling working media; the temperature control mode can be simultaneously started in the test mode.
In the reference pressure setting mode, external air 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 portion of the first alloy substrate 210, so that the reference pressure setting of the piezoresistive sensitive chip is completed.
The device firstly works in a calibration mode, an inlet 233 of a conversion channel for calibration is connected with a high-precision air pressure calibration source, reference air pressure is set at a certain fixed air pressure value, the device can be arranged in a device capable of accurately controlling temperature, the input air pressure value is gradually adjusted, signals of each pressure resistance sensitive chip 000 are amplified through an instrument amplifying circuit 102, an ADC 103 module is converted into digital signals and transmitted to an MCU104, and synchronously, signals of a temperature sensor 101 are amplified, the ADC 103 is converted into digital signals and transmitted to the MCU104 together, the MCU104 module can record calibration air pressure input and temperature, and fitting relational expressions between each pressure sensitive chip 000 and temperature output and air pressure input and temperature set values are formed and stored under different temperature conditions.
In a 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, the reference air pressure is set to be a stable value as required, the external air pressure is input to generate pressure difference at two ends of the piezoresistive sensitive chip 000, and a signal obtained by the temperature sensor 101 is amplified by the instrument amplifying circuit 102 and converted by the ADC 103 to be obtained by the MCU104, and the MCU104 module obtains a fitting relation between the output of each pressure sensitive chip 000 and the air pressure input under the temperature condition automatically searched according to the signal of the temperature sensor 101, and obtains the output value of the voltage signal of each pressure sensitive chip 000 by using the fitting relation.
During the test, according to the requirements of the application scenario, a cooling gas can be input into the temperature control channel 221c to maintain the temperature field of the piezoresistive sensitive chip 000.
The front surface of the first alloy substrate 210 is provided with an open cavity 213 for accommodating the first circuit piece 110 and the second circuit piece 120; wherein the first circuit chip 110 is attached to the first alloy substrate 210 by using a sealing adhesive or a screw according to the mounting position of the piezoresistive sensitive chip 000; the second circuit piece 120 is attached to the first alloy substrate 210 by using sealing glue or threads on the sidewall step structure 214; the top of the first alloy substrate 210 is further provided with a step structure 215 for bonding the fourth alloy substrate 240 to seal the open cavity 212, and the bonding mode may be a sealing adhesive or a thread, which is convenient for subsequent disassembly and assembly and maintenance of the piezoresistive sensitive chip or circuit board. The back of the first alloy substrate 210 is provided with an open cavity 216 for placing a second alloy substrate 220 and a third alloy substrate 230; optionally, a boss 217 is further disposed in the cavity on the front surface of the first alloy substrate 210 to match the height difference between the piezoresistive sensitive chip 000 and the first circuit chip 110, so as to facilitate wire bonding. All the steps of the first alloy substrate 210 are provided with sealing rings 201 to ensure the air tightness of the system. An electromagnet driver or a magnetostrictive driver 219 is arranged on the side wall of the first alloy substrate 210 to realize the movement of the second alloy substrate;
optionally, the moving function of the second alloy substrate 220 may also be realized by manually toggling a protruding shaft structure 223 (as shown in the schematic diagram of embodiment 2) located at the outer side of the package body and connected to the second alloy substrate 220, so as to implement the conversion between the calibration or temperature control mode and the test mode;
the outer side of the third alloy substrate 230 is respectively provided with a stainless steel pipe air port 235 corresponding to the air guiding air hole or the functional module, and a hose 236 may be further sleeved outside the stainless steel pipe 235 for facilitating connection with an external device to be tested or an operating device.
Example 2
Referring to fig. 14 and 15, the difference between this embodiment and embodiment 1 is that the second alloy substrate 220 and the third alloy substrate 230 are disposed in the same side-open cavity 217 of the first alloy substrate 210, and may also be divided into two parts to be disposed on two sides of the first alloy substrate 210; the air guide holes 211 are correspondingly converted according to the positions of the second alloy base plates 220, the through air guide hole structure in the embodiment 1 is communicated with the front surface and the back surface of the first alloy base plate 210, and the air guide holes 211 in the embodiment are communicated with the front surface and the same or different side surfaces of the first alloy base plate 210; the rest refer to example 1.
Example 3
Referring to fig. 16, the difference between this embodiment and embodiment 1 is that the first circuit piece 110 is placed in the front open cavity 212 of the first alloy substrate 210 and the second circuit piece 120 is placed in the back open cavity 215 of the first alloy substrate 210 during assembly, and the first circuit piece and the second circuit piece are respectively connected by using bonding, bolts, or the like, so that maintenance and replacement are facilitated. Placing a second alloy substrate 220 and a third alloy substrate 230 in the same side-open cavity 217 of the first alloy substrate 210, or dividing the second alloy substrate into two parts and placing the two parts on two sides of the first alloy substrate 210, respectively, and performing corresponding conversion on the air guide holes 130 according to the position of the second alloy substrate, as in example 2; the top and the bottom of the first alloy substrate 210 are respectively provided with a fourth alloy substrate 240 for sealing the open cavity; the rest refer to example 1.
Example 4
Referring to fig. 17, the piezoresistive sensitive chip in this embodiment is an absolute piezoresistive sensitive chip 000c, the piezoresistive sensitive chip 000c is a silicon substrate, and the piezoresistive strip 001, the passivation layer 002, the Pad 003 and the solder ball 006 are formed on the front surface of the piezoresistive sensitive chip 000c through processes such as epitaxy, oxidation, diffusion, sputtering and the like; an etching process is adopted to form an open cavity 004 on the back of the piezoresistive sensitive chip 000 c; after the open back cavity 004 is evacuated, another piece of silicon or glass 010 is bonded to the back side of the piezoresistive sensitive chip 000c to seal the open cavity 004 and form the absolute pressure piezoresistive sensitive chip 000 c. Wherein Pad 004 includes at least 1 power Pad, 1 ground Pad, and 2 signal pads.
In order to be compatible with the assembly system described in embodiment 1, solder balls are formed on the front surface of the piezoresistive sensitive chip 000 and flip-chip bonded on the interconnected substrate 020 with air holes, and an electric wiring layer and a bonding pad corresponding to the solder balls are arranged on the solder balls; then, a gap between the piezoresistive sensitive chip 000 and the ceramic plate 020 is sealed by SU8 or BCB glue to form a sealing ring 021'; bonding bodies of the piezoresistive sensitive chips 000 and the interconnection substrate 020 are bonded to corresponding air guide holes of the first alloy substrate 210 one by using sealant; the first alloy substrate 210 is further provided with a first circuit piece 110, and the interconnection substrate 020 is electrically connected to the first circuit piece through wire bonding to lead out signals of the piezoresistive sensitive chip 000.
Preferably, the first circuit chip 110 has at least one piezoresistive sensitive chip 000b for temperature compensation;
optionally, each piezoresistive sensitive chip 000 may correspond to one interconnection substrate 020, and a plurality of piezoresistive sensitive chips 000 may also correspond to one interconnection substrate 020 to replace the first circuit chip 110;
optionally, two interconnection substrates are added below each piezoresistive sensitive chip 000 to further reduce the assembly stress;
optionally, a microchannel may be embedded in the interconnection substrate for heat dissipation management;
optionally, the interconnection substrate may adopt a ceramic wafer, a silicon interposer or a glass substrate;
vacuumizing the back cavity of the piezoresistive sensor chip 000, and applying an external air pressure P1 to the front resistive film 005 (not shown in the figure) of the piezoresistive sensor chip 000 through the air 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 the electrical signal is output, processed and calculated.
Alternatively, the assembly system for the pressure test may be any of those mentioned in reference to examples 1 to 3.
The rest refer to example 1.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (10)
1. An array pressure measurement device, comprising:
the piezoresistive sensitive chip is used for applying reference pressure on the front surface of the piezoresistive sensitive chip and applying external gas pressure on the back surface of the piezoresistive sensitive chip to generate pressure difference, a piezoresistive strip, a passivation layer and a Pad are formed on the front surface of the piezoresistive sensitive chip, and an open cavity is formed on the back surface of the piezoresistive sensitive chip;
the circuit system is integrated on the first circuit chip and the second circuit chip, comprises a temperature sensor chip, an instrument amplifying circuit, an ADC module and an MCU, and is used for converting the pressure difference generated by the piezoresistive sensitive chip into an electric signal which is in direct proportion to the pressure change, outputting the electric signal and processing and calculating the electric signal;
the gas path system is used for providing gas pressure and acting on two sides of the piezoresistive sensitive chip to generate the pressure difference, and is formed by hermetically connecting a cavity on the back of the piezoresistive sensitive chip, a first alloy substrate, a second alloy substrate and a third alloy substrate; the first alloy substrate, the second alloy substrate and the third alloy substrate are provided with air guide holes penetrating through the front surface and the back surface and a reference pressure air path for setting 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 an air guide hole and connected with a cavity on the back of the piezoresistive sensitive chip.
2. The array pressure measuring device of claim 1, wherein the first alloy substrate is configured with an open cavity and a mounting structure for receiving and mounting the first die and the second die.
3. The array pressure measuring device of claim 2, wherein the first alloy substrate has an open cavity and a fixing structure on the back for placing the second alloy substrate and the third alloy substrate.
4. The array pressure measuring device of claim 2, wherein the second alloy substrate and the third alloy substrate are disposed in the same side opening cavity of the first alloy substrate, or divided into two parts disposed on two sides of the first alloy substrate.
5. The array pressure measurement device of claim 2, wherein the first die is disposed within the open front cavity of the first alloy substrate and the second die is disposed within the open back cavity of the first alloy substrate;
the second alloy substrate and the third alloy substrate are arranged in an air cavity opened on the same side face of the first alloy substrate, or can be divided into two parts which are respectively arranged on two sides of the first alloy substrate.
6. The array pressure measurement device according to any one of claims 2 to 5, wherein 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 first alloy substrate side wall step structure; and stainless steel pipe air ports corresponding to the air guide holes are respectively arranged on the outer sides of the third alloy substrates.
7. The array type pressure measuring device according to any one of claims 1 to 6, wherein the air vents are divided into a calibration passage, a test passage and a temperature control passage;
the second alloy substrate is movable, and the array type pressure measuring device can be switched between a calibration passage or a temperature control passage and a test passage by moving the second alloy substrate;
the array pressure measuring device further comprises a device for driving the second alloy substrate to move, wherein the device is an electromagnet driver or a magnetostrictive driver arranged on the side wall of the first alloy substrate, or a protruding shaft structure which is positioned on the second alloy substrate and connected to the outer side of the packaging body, so that the second alloy substrate can move.
8. The array pressure measuring device of claim 1, wherein the temperature sensor chip is implemented using the piezoresistive sensitive chip.
9. The array pressure measuring device of claim 8, wherein another piece of silicon or glass is bonded to the back surface of the piezoresistive sensor chip after the open cavity on the back surface of the piezoresistive sensor chip is evacuated to seal the open cavity, thereby forming the absolute pressure piezoresistive sensor chip.
10. The array pressure measuring device of claim 1, wherein an interconnect substrate with air vents is disposed between the piezoresistive sensitive die and the first alloy substrate boss.
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| CN202110343741.XA CN112880902A (en) | 2021-03-30 | 2021-03-30 | Array type pressure measuring device |
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| CN202110343741.XA CN112880902A (en) | 2021-03-30 | 2021-03-30 | Array type pressure measuring device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114839942A (en) * | 2022-06-30 | 2022-08-02 | 中恒数网(江苏)科技有限公司 | High-stability trigger type intelligent control system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114839942A (en) * | 2022-06-30 | 2022-08-02 | 中恒数网(江苏)科技有限公司 | High-stability trigger type intelligent control system |
| CN114839942B (en) * | 2022-06-30 | 2022-09-09 | 中恒数网(江苏)科技有限公司 | High-stability trigger type intelligent control system |
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