A multi-channel pressure measurement unit and a pressure measurement device

Abstract

The present invention relates to the field of semiconductor technology, and in particular to a pressure measuring unit and a pressure measuring device. The pressure measuring unit comprises: a pressure sensor chip, a temperature sensitive chip, an interconnection substrate, and a ceramic packaging substrate; the pressure sensor chip and the temperature sensitive chip are respectively bonded to the interconnection substrate, the pressure sensor chip and the temperature sensitive chip are arranged adjacent to each other, the interconnection substrate is bonded to the ceramic packaging substrate, and the material of the interconnection substrate is the same as that of the pressure sensor chip and the temperature sensitive chip; a first air guide channel and a second air guide channel are provided on the interconnection substrate; a third air guide channel and a fourth air guide channel are provided on the ceramic packaging substrate; a reference pressure is introduced through the fourth air guide channel, and a test pressure is introduced through the third air guide channel, so that a pressure difference is formed between the front and back sides of the pressure sensor chip, so as to solve the problem of thermodynamic parameter mismatch between the pressure sensor chip and the temperature sensitive chip and the ceramic packaging substrate, and improve product performance.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a multi-channel pressure measurement unit and a pressure measurement device. Background Art

[0002] The existing multi-channel pressure measurement device installs the piezoresistive MEMS sensor chips in the form of an array on a circuit board. The entire circuit board is assembled on an alloy base. A temperature sensitive chip is integrated on the circuit board to monitor the on-site temperature of the piezoresistive MEMS sensor chip array to achieve temperature drift compensation, thereby improving the measurement accuracy.

[0003] However, when directly mounting the piezoresistive MEMS sensor and the temperature sensitive chip on the circuit board, there is a technical problem of thermodynamic parameter mismatch. Summary of the invention

[0004] In view of the above problems, the present invention is proposed to provide a multi-channel pressure measurement unit and a pressure measurement device that overcome the above problems or at least partially solve the above problems.

[0005] In a first aspect, an embodiment of the present invention provides a pressure measurement unit, comprising:

[0006] Pressure sensor chips, temperature sensitive chips, interconnect substrates, ceramic packaging substrates;

[0007] The pressure sensor chip and the temperature sensitive chip are respectively bonded to the interconnection substrate, and the pressure sensor chip and the temperature sensitive chip are arranged adjacent to each other. The interconnection substrate is bonded to the ceramic packaging substrate, and the material of the interconnection substrate is the same as that of the pressure sensor chip and the temperature sensitive chip.

[0008] The interconnection substrate is provided with a first air guide channel corresponding to the pressure sensor chip and a second air guide channel corresponding to the temperature sensitive chip;

[0009] The ceramic packaging substrate is provided with a third gas guiding channel corresponding to the first gas guiding channel and a fourth gas guiding channel corresponding to the second gas guiding channel;

[0010] A reference pressure is introduced through the fourth air channel to act on the front side of the pressure sensor chip, and a test pressure is introduced through the third air channel to act on the back side of the pressure sensor chip to form a pressure difference between the front side and the back side of the pressure sensor chip.

[0011] Preferably, it also includes:

[0012] A first metal tube is connected to the third air guide channel at the bottom end of the ceramic packaging substrate, the first metal tube is connected to a first access hose, and the first access hose is used to pass the reference pressure;

[0013] A second metal tube is connected to the fourth air guide channel at the bottom end of the ceramic packaging substrate, and the second metal tube is connected to a second access hose for passing a test pressure.

[0014] Preferably, the method further comprises: a sealing cover, which is disposed on the ceramic packaging substrate and covers the pressure sensor chip, the temperature sensitive chip and the interconnection substrate.

[0015] Preferably, the interconnection substrate is any one of the following:

[0016] TSV interconnect substrate, TGV interconnect substrate.

[0017] Preferably, the pressure sensor chip and the temperature sensitive chip are both differential pressure piezoresistive MEMS chips or absolute pressure piezoresistive MEMS chips.

[0018] Preferably, when the pressure sensor chip and the temperature sensitive chip are both differential pressure piezoresistive MEMS chips, the differential pressure piezoresistive MEMS chip includes:

[0019] A first silicon substrate and a first passivation layer from bottom to top, wherein a first back cavity structure is provided on the first silicon substrate;

[0020] A first electrode is disposed on the first passivation layer, and a first piezoresistive structure is located inside the first passivation layer.

[0021] Preferably, the first silicon substrate of the differential pressure piezoresistive MEMS chip is bonded to the interconnection substrate by a sealing adhesive material.

[0022] Preferably, when the pressure sensor chip and the temperature sensitive chip are both absolute pressure piezoresistive MEMS chips, the absolute pressure piezoresistive MEMS chip includes:

[0023] A second passivation layer, a second silicon substrate and a third silicon substrate from bottom to top, wherein the second silicon substrate is provided with a second back cavity structure, and the third silicon substrate is used for sealing the second back cavity structure;

[0024] A second electrode is disposed on the second passivation layer, and a second piezoresistive structure is located inside the second passivation layer.

[0025] Preferably, the second passivation layer of the absolute pressure piezoresistive MEMS chip is connected to the interconnection substrate via a sealing ring.

[0026] In a second aspect, the present invention further provides a pressure measuring device, comprising:

[0027] A first substrate, a second substrate, a pressure measuring unit, an operational amplifier, an analog-to-digital conversion unit, and a processor;

[0028] Each pressure measurement unit is welded on the first substrate via a dual in-line electrode pin;

[0029] The lower side of the first substrate is connected to the second substrate via an inter-board electrical interconnection structure;

[0030] The operational amplifier, the analog-to-digital conversion unit, and the processor are all integrated on the second substrate, and the operational amplifier, the analog-to-digital conversion unit, and the processor are connected in sequence.

[0031] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0032] A pressure measurement unit provided by the present invention comprises: a pressure sensor chip, a temperature sensitive chip, an interconnection substrate, and a ceramic packaging substrate; the pressure sensor chip and the temperature sensitive chip are respectively bonded to the interconnection substrate, and the pressure sensor chip and the temperature sensitive chip are arranged adjacent to each other; the interconnection substrate is bonded to the ceramic packaging substrate; the material of the interconnection substrate is the same as that of the pressure sensor chip and the temperature sensitive chip; a first air guide channel corresponding to the pressure sensor chip and a second air guide channel corresponding to the temperature sensitive chip are provided on the interconnection substrate; a third air guide channel corresponding to the first air guide channel and a third air guide channel corresponding to the second air guide channel are provided on the ceramic substrate a fourth gas conducting channel corresponding to the gas channel; a reference pressure is introduced through the fourth gas conducting channel to act on the front sides of the pressure sensor chip and the temperature sensitive chip, and a test pressure is introduced through the third gas conducting channel to act on the back side of the pressure sensor chip to form a pressure difference between the front side and the back side of the pressure sensor chip, and then an interconnection substrate is arranged at the connection between the pressure sensor chip and the temperature sensitive chip and the ceramic substrate respectively. Since the interconnection substrate and the pressure sensor chip and the temperature sensitive chip are made of the same material, the problem of thermodynamic parameter mismatch between the pressure sensor chip and the temperature sensitive chip and the ceramic packaging substrate respectively is solved, thereby improving product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Also, throughout the accompanying drawings, the same reference figures are used to represent the same components. In the drawings:

[0034] Figure 1 A schematic diagram of the structure of a pressure measuring unit in an embodiment of the present invention is shown;

[0035] Figure 2 A schematic diagram of the structure of a differential pressure MEMS chip in an embodiment of the present invention is shown;

[0036] Figure 3 A schematic diagram showing the structure of a differential pressure MEMS chip bonded to an interconnect substrate in an embodiment of the present invention is shown;

[0037] Figure 4 A schematic diagram of the structure of an absolute pressure MEMS chip in an embodiment of the present invention is shown;

[0038] Figure 5 It shows a schematic diagram of the structure in which an absolute pressure MEMS chip is bonded to an interconnect substrate in an embodiment of the present invention;

[0039] Figure 6 A schematic structural diagram of a pressure measuring device in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0040] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0041] An embodiment of the present invention provides a pressure measurement unit, such as Figure 1 As shown, including:

[0042] Pressure sensor chip 020, temperature sensitive chip 010, interconnection substrate 040, ceramic packaging substrate 080;

[0043] The pressure sensor chip 020 and the temperature sensitive chip 010 are respectively bonded to the interconnection substrate 040, and the pressure sensor chip 020 and the temperature sensitive chip 010 are arranged adjacent to each other. The interconnection substrate 040 is bonded to the ceramic package substrate 080, and the material of the interconnection substrate 040 is the same as that of the pressure sensor chip 020 and the temperature sensitive chip 010.

[0044] A first gas conducting channel 041 corresponding to the pressure sensor chip 020 and a second gas conducting channel 042 corresponding to the temperature sensitive chip 010 are provided on the interconnection substrate 040; a third gas conducting channel 081 corresponding to the first gas conducting channel 041 and a fourth gas conducting channel 083 corresponding to the second gas conducting channel 042 are provided on the ceramic packaging substrate; a reference pressure is introduced through the fourth gas conducting channel 083 to act on the front sides of the pressure sensor chip 020 and the temperature sensitive chip 010, and a test pressure is introduced through the third gas conducting channel 081 to act on the back side of the pressure sensor chip 020, so as to form a pressure difference between the front side and the back side of the pressure sensor chip 020.

[0045] In an optional implementation, the interconnection substrate 040 specifically adopts any one of the following: a TSV interconnection substrate, a TGV interconnection substrate.

[0046] Since the pressure sensor chip 020 and the temperature sensitive chip 010 are respectively made of silicon material, and the TSV interconnect substrate and the TGV interconnect substrate are also made of silicon material, bonding the pressure sensor chip 202 and the temperature sensitive chip 010 to the interconnect substrate 040 made of silicon material can solve the problem of material thermodynamic parameter mismatch.

[0047] At the same time, a first gas-conducting channel 041 corresponding to the pressure sensor chip 020 and a second gas-conducting channel 042 corresponding to the temperature-sensitive chip are provided on the interconnection substrate 040. Specifically, since the interconnection substrate 040 is a TSV interconnection substrate or a TGV interconnection substrate, the gas-conducting channel is provided on the TSV interconnection substrate or the TGV interconnection substrate, so that the pressure sensor chip 020 and the temperature-sensitive chip 010 can be compactly integrated, which can meet the current demand for small device size.

[0048] Among them, the TSV interconnect substrate is specifically a substrate for packaging technology that makes vertical through holes between chips or between wafers; the TGV interconnect substrate is a substrate for packaging technology of glass through holes. Both substrates are made of silicon or glass with a thermal expansion coefficient similar to that of silicon.

[0049] In each pressure measurement unit, the pressure sensor chip 020 is disposed adjacent to the temperature sensitive chip 010 , that is, the temperature sensitive chip 010 is disposed close to the pressure sensor chip 020 , which can provide a more accurate reference signal of the temperature value for temperature drift suppression.

[0050] The single pressure measurement unit allows the test pressure to pass through the third air guide channel 081 opened on the ceramic package substrate 080, and allows the reference pressure to pass through the fourth air guide channel 083 opened on the ceramic package substrate 080, so that the reference pressure reaches the front of the pressure sensor chip 020 and the temperature sensitive chip 010, and the test pressure reaches the back of the pressure sensor chip 020, so that the pressure difference between the front and back of the pressure sensor chip 020 is obtained, based on the pressure difference, an electrical signal proportional to the pressure difference change is obtained, so as to obtain the actual pressure value.

[0051] Among them, the third air-conducting channel 081 is connected with the first air-conducting channel 041, so that the test pressure introduced through the third air-conducting channel 081 directly reaches the back of the pressure sensor chip 020, that is, the back cavity structure. One end of the second air-conducting channel 042 is connected to the back of the temperature-sensitive chip 010, that is, the back cavity structure, and the other end is connected to the surface of the interconnection substrate 040. By setting the pressure difference on both sides of the temperature-sensitive chip 010 to zero, that is, the pressures set on both sides are the same, the temperature-sensitive chip 010 maintains a zero-point output state. At this time, the output of the temperature-sensitive chip 010 directly reflects the change in temperature, so the operating temperature of the piezoresistive strip of the pressure sensor chip 020 can be obtained by measuring the change in the piezoresistive strip of the temperature-sensitive chip.

[0052] In an optional implementation, a first metal tube 082 is connected to the third air guide channel 081 at the bottom end of the ceramic packaging substrate 080 , and the first metal tube 082 is connected to a first access hose 400 , and the first access hose 400 is used to introduce a reference pressure.

[0053] A second metal tube 084 is connected to the fourth air guide channel 083 at the bottom end of the ceramic packaging substrate 080 . The second metal tube 084 is connected to a second access hose 500 . The second access hose 500 is used to pass the test pressure.

[0054] The method of inserting a metal tube into the air guide channel and then connecting the access hose improves the air tightness of the incoming air source, and such a connection method is also convenient for disassembly and assembly.

[0055] In an optional implementation, the pressure measurement unit further includes: a sealing cover 050 , which is disposed on the ceramic packaging substrate 080 and covers the pressure sensor chip 020 , the temperature sensitive chip 010 and the interconnection substrate 040 .

[0056] The sealing cover 050 is specifically made of aluminum material and is used to protect and seal the chip inside the cover.

[0057] The sealing cover 050 is bonded to the ceramic packaging substrate 080 using a low-stress adhesive 070 to ensure good air tightness of the air guide channel.

[0058] The pressure sensor chip 020 and the temperature sensitive chip 010 are both differential pressure MEMS chips.

[0059] Specific as Figure 2 The figure shows the structure of a single pressure measurement unit using a differential pressure MEMS chip.

[0060] The differential pressure piezoresistive MEMS chip comprises: a first silicon substrate 014 and a first passivation layer 013 from bottom to top, wherein a first back cavity structure A is provided on the first silicon substrate 014 ; a first electrode 012 is provided on the first passivation layer, and a first piezoresistive structure 011 is located inside the first passivation layer 013 .

[0061] The first electrode 012 at least includes a power electrode, a ground electrode, and two signal electrodes.

[0062] like Figure 3 As shown, when a differential pressure MEMS chip is used, the first silicon substrate 014 of the differential pressure MEMS chip is bonded to the interconnection substrate 040 through a sealing bonding material 030 to achieve a sealed connection.

[0063] like Figure 4 As shown, in one embodiment of the present invention, an absolute pressure piezoresistive MEMS chip structure is also adopted. The absolute pressure piezoresistive MEMS chip includes: a second passivation layer 016, a second silicon substrate 017 and a third silicon substrate 015 from bottom to top. The second silicon substrate 017 opens a second back cavity B, and the third silicon substrate 015 is used to seal the second back cavity B.

[0064] In one embodiment of the present invention, the absolute pressure piezoresistive MEMS chip is inverted compared to the differential pressure piezoresistive MEMS chip, and a second electrode 018 is disposed on the second passivation layer 016, and a second piezoresistive structure 019 is disposed inside the second passivation layer 016. The second electrode 018 also includes at least one power electrode, one ground electrode, and two signal electrodes.

[0065] like Figure 5 As shown, when an absolute pressure type piezoresistive MEMS chip is connected to an interconnect substrate 040, since the second passivation layer 016 has a protruding second electrode 018 structure, when the second passivation layer 016 of the absolute pressure type piezoresistive MEMS chip is connected to the interconnect substrate 040, it is specifically connected to the interconnect substrate 040 through a sealing ring 032, thereby achieving a sealed connection. The sealing ring 032 can be made of silicone rubber or silicone sealant, which is not limited here.

[0066] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0067] A pressure measurement unit provided by the present invention comprises: a pressure sensor chip, a temperature sensitive chip, an interconnection substrate, and a ceramic packaging substrate; the pressure sensor chip and the temperature sensitive chip are respectively bonded to the interconnection substrate, and the pressure sensor chip and the temperature sensitive chip are arranged adjacent to each other; the interconnection substrate is bonded to the ceramic packaging substrate; the material of the interconnection substrate is the same as that of the pressure sensor chip and the temperature sensitive chip; a first air guide channel corresponding to the pressure sensor chip and a first air guide channel corresponding to the temperature sensitive chip are provided on the interconnection substrate; a third air guide channel corresponding to the first air guide channel and a second air guide channel corresponding to the temperature sensitive chip are provided on the ceramic substrate; a fourth gas conducting channel corresponding to the gas channel; a reference pressure is introduced through the fourth gas conducting channel to act on the front sides of the pressure sensor chip and the temperature sensitive chip, and a test pressure is introduced through the third gas conducting channel to act on the back side of the pressure sensor chip to form a pressure difference between the front side and the back side of the pressure sensor chip, and then an interconnection substrate is arranged at the connection between the pressure sensor chip and the temperature sensitive chip and the ceramic substrate respectively. Since the interconnection substrate and the pressure sensor chip and the temperature sensitive chip are made of the same material, the problem of thermodynamic parameter mismatch between the pressure sensor chip and the temperature sensitive chip and the ceramic packaging substrate respectively is solved, thereby improving product performance.

[0068] Embodiment 2

[0069] Based on the same inventive concept, the second embodiment of the present invention also provides a pressure measuring device, such as Figure 6 As shown, including:

[0070] A first substrate 100, a second substrate 300, a plurality of pressure measuring units 000 as described in the first embodiment, an operational amplifier 310, an analog-to-digital conversion unit 320, and a processor 330;

[0071] Each pressure measurement unit 000 is respectively welded on the first substrate 100 via a dual in-line electrode pin 060;

[0072] The first substrate 100 is connected to the second substrate 300 via an inter-board electrical interconnection structure 200;

[0073] The operational amplifier 310 , the analog-to-digital conversion unit 320 , and the processor 330 are all integrated on the second substrate 300 , and the operational amplifier 310 , the analog-to-digital conversion unit 320 , and the processor 330 are connected in sequence.

[0074] In an optional implementation, the first substrate 100 and the second substrate 300 are both PCB substrates.

[0075] In an optional implementation, the operational amplifier 310 , the analog-to-digital conversion unit 320 , and the processor 330 are all integrated on the second substrate 300 by wire bonding or pasting.

[0076] The height of the inter-board electrical interconnect structure 200 is set according to the heights of the operational amplifier 310 , the analog-to-digital conversion unit 320 , and the processor 330 .

[0077] The inter-board electrical interconnection structure 200 may be in the form of solder balls or solder columns, which is not limited herein.

[0078] In an optional implementation, based on the circuit system setting, digital fitting and compensation are performed to improve the measurement accuracy, and the specific steps include:

[0079] In the digital fitting and compensation setting state, the pressure measuring device is placed in a temperature-controlled environment, the ambient temperature and the introduced air pressure sources P1, P2, P3, P4... and the reference air pressure source are set, and the electrical signal generated by each pressure measuring unit based on the pressure difference and the ambient temperature is transmitted to the operational amplifier 310, and after signal amplification, it enters the analog-to-digital conversion unit 320 for analog-to-digital conversion processing, and finally enters the processor 330 to record the corresponding input pressure and the generated electrical signal under different ambient temperature conditions, and establish a relationship between the input pressure and the generated electrical signal under different ambient temperature conditions.

[0080] In the test state, the processor calls the fitting curve according to the selected air pressure channel and the actual temperature measured by the temperature sensitive chip, and calculates the measured pressure from the voltage value output by the pressure sensing chip.

[0081] The pressure measuring device can also be used to calibrate and detect faults when the error exceeds a preset range, thereby improving the measurement accuracy. When used in wind tunnel tests or flight tests, it can achieve multi-channel rapid measurement of pressure.

[0082] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0083] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A pressure measuring unit, characterized in that: include: Pressure sensor chips, temperature sensitive chips, interconnect substrates, ceramic packaging substrates; The pressure sensor chip and the temperature sensitive chip are respectively bonded to the interconnection substrate, and the pressure sensor chip and the temperature sensitive chip are arranged adjacent to each other. The interconnection substrate is bonded to the ceramic packaging substrate, and the material of the interconnection substrate is the same as that of the pressure sensor chip and the temperature sensitive chip. The interconnection substrate is provided with a first air guide channel corresponding to the pressure sensor chip and a second air guide channel corresponding to the temperature sensitive chip; The ceramic packaging substrate is provided with a third gas guiding channel corresponding to the first gas guiding channel and a fourth gas guiding channel corresponding to the second gas guiding channel; A reference pressure is introduced through the fourth air channel to act on the front side of the pressure sensor chip, and a test pressure is introduced through the third air channel to act on the back side of the pressure sensor chip to form a pressure difference between the front side and the back side of the pressure sensor chip.

2. The pressure measuring unit according to claim 1, characterized in that Also includes: A first metal tube is connected to the third air guide channel at the bottom end of the ceramic packaging substrate, the first metal tube is connected to a first access hose, and the first access hose is used to pass the reference pressure; A second metal tube is connected to the fourth air guide channel at the bottom end of the ceramic packaging substrate, and the second metal tube is connected to a second access hose for passing a test pressure.

3. The pressure measuring unit according to claim 1, characterized in that Also includes: The sealing cover is disposed on the ceramic packaging substrate and covers the pressure sensor chip, the temperature sensitive chip and the interconnection substrate.

4. The pressure measuring unit according to claim 1, characterized in that: The interconnect substrate is specifically any one of the following: TSV interconnect substrate, TGV interconnect substrate.

5. The pressure measuring unit according to claim 1, characterized in that: The pressure sensor chip and the temperature sensitive chip are both differential pressure piezoresistive MEMS chips or absolute pressure piezoresistive MEMS chips.

6. The pressure measuring unit according to claim 5, characterized in that When the pressure sensor chip and the temperature sensitive chip are both differential pressure piezoresistive MEMS chips, the differential pressure piezoresistive MEMS chip includes: A first silicon substrate and a first passivation layer from bottom to top, wherein a first back cavity structure is provided on the first silicon substrate; A first electrode is disposed on the first passivation layer, and a first piezoresistive structure is located inside the first passivation layer.

7. The pressure measuring unit according to claim 6, characterized in that The first silicon substrate of the differential pressure piezoresistive MEMS chip is bonded to the interconnection substrate by a sealing bonding material.

8. The pressure measuring unit according to claim 5, characterized in that When the pressure sensor chip and the temperature sensitive chip are both absolute pressure piezoresistive MEMS chips, the absolute pressure piezoresistive MEMS chip includes: A second passivation layer, a second silicon substrate and a third silicon substrate from bottom to top, wherein the second silicon substrate is provided with a second back cavity structure, and the third silicon substrate is used for sealing the second back cavity structure; A second electrode is disposed on the second passivation layer, and a second piezoresistive structure is located inside the second passivation layer.

9. The pressure measuring unit according to claim 8, characterized in that The second passivation layer of the absolute pressure piezoresistive MEMS chip is connected to the interconnection substrate through a sealing ring.

10. A pressure measuring device, characterized in that: include: A first substrate, a second substrate, a plurality of pressure measuring units according to any one of claims 1 to 9, an operational amplifier, an analog-to-digital conversion unit, and a processor; Each pressure measurement unit is welded on the first substrate via a dual in-line electrode pin; The lower side of the first substrate is connected to the second substrate via an inter-board electrical interconnection structure; The operational amplifier, the analog-to-digital conversion unit, and the processor are all integrated on the second substrate, and the operational amplifier, the analog-to-digital conversion unit, and the processor are connected in sequence.

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