A wafer-level array air pressure measurement device

Abstract

A wafer-level array-type air pressure measurement device belongs to the technical field of pressure sensors. The present invention solves the problem that the volume of conventional multi-channel pressure testing equipment cannot be further reduced. The present invention comprises a housing assembly, a wafer-level air pressure measurement array, a Kovar alloy pressure-inducing conduit, and a porous isolation array-type glass support layer. The wafer-level air pressure measurement array is arranged in the housing assembly. The wafer-level air pressure measurement array has m×n measurement channels, each of which is connected to the outside through a Kovar alloy pressure-inducing conduit. The m×n Kovar alloy pressure-inducing conduits extend out of the housing assembly through the porous isolation array-type glass support layer.

Description

Technical Field

[0001] The invention relates to a wafer-level array-type air pressure measuring device, belonging to the technical field of pressure sensors. Background Art

[0002] Multi-channel pressure measurement devices or systems usually use independent, discrete sensitive elements. For conventional multi-channel pressure test equipment, see Figure 1 As shown, the measurement of multi-channel air pressure signals is achieved through the support and interconnection of the carrier board, so it is difficult to further reduce the volume. Therefore, the existing multi-channel high-precision pressure measurement equipment has the problem of difficulty in improving the integration and reducing the volume. As a result, in the wind tunnel test or massive channel air pressure test in the design of aircraft and engine, there are fewer air pressure measurement points that can be arranged in the scaled aircraft, resulting in a lack of data for aircraft design. Once the point arrangement is increased, the scale of the aircraft must be increased, which in turn places higher requirements on the scale of the wind tunnel.

[0003] The sensitive chip used for conventional pressure measurement is formed by patterning and slicing a complete silicon wafer to form discrete components for pressure measurement. In this way, each pressure-sensitive chip requires independent signal wiring and sealing, which affects the volume. However, if slicing is not performed, it is difficult to solve problems such as isolated measurement between pressures and electrode lead-out, and the function of multi-channel pressure measurement cannot be completed. Summary of the invention

[0004] In view of the problem that the volume of conventional multi-channel pressure testing equipment cannot be further reduced, the present invention provides a wafer-level array-type air pressure measuring device.

[0005] The present invention describes a wafer-level array-type air pressure measurement device, comprising a shell assembly, a wafer-level air pressure measurement array 100, a Kovar alloy pressure conduit 106 and a porous isolation array-type glass support layer 107. The wafer-level air pressure measurement array 100 is arranged in the shell assembly. The wafer-level air pressure measurement array 100 has m×n measurement channels, each of which is connected to the outside through a Kovar alloy pressure conduit 106. The m×n Kovar alloy pressure conduits 106 extend out of the shell assembly through the porous isolation array-type glass support layer 107.

[0006] Preferably, it also includes a signal acquisition and control circuit component 104 and a connection 105, and the housing component includes a base 101 and a shell 102; the shell 102 is buckled on the base 101 to form a closed space, and the top plate of the shell 102 is provided with m×n array holes;

[0007] The signal acquisition and control circuit assembly 104 is mechanically fixed to the base 101 by means of fasteners 103 , and the wafer-level air pressure measurement array 100 is electrically connected to the signal acquisition and control circuit assembly 104 by means of wiring 105 ;

[0008] The top surface of the porous isolation array glass support layer 107 is fixed to the inner surface of the top plate of the housing 102 , and the bottom surface of the porous isolation array glass support layer 107 is fixed to the wafer-level air pressure measurement array 100 , and the holes are aligned.

[0009] Preferably, the wafer-level air pressure measurement array 100 includes a pressure-sensitive capacitor 1, a channel gating function chip 2, an electrode protection layer 3, a noble metal electrode 4, a silicon wafer silicon cup wafer layer 5, an insulating isolation layer 6 and a Kovar transfer layer 7;

[0010] The silicon wafer layer 5 and the Kovar transfer layer 7 are bonded and connected via an insulating isolation layer 6; both the insulating isolation layer 6 and the Kovar transfer layer 7 have m×n array holes, and the measurement channels 9 are formed in one-to-one correspondence;

[0011] An m×n cavity array is provided on the upper surface of the silicon cup wafer layer 5, each cavity serves as a silicon cup 8, and each silicon cup 8 is connected to a measurement channel 9;

[0012] The lower surface of the bottom film of each silicon cup 8 is made of an m×n array of pressure-sensitive capacitors 1 by magnetron sputtering technology. A noble metal electrode 4 is arranged at each corner of each pressure-sensitive capacitor 1 to form a bridge structure. The differential capacitor structure is used to sense the pressure of the gas entering the measurement channel.

[0013] All the noble metal electrodes 4 are covered and protected by the electrode protection layer 3, and the electrode protection layer 3 is an m×n array hole structure, and the hole positions are used to accommodate the pressure-sensitive capacitor 1;

[0014] P channel gating function chips 2 are arranged on the lower surface of the silicon cup wafer layer 5, and m×n bridge leads are formed by magnetron sputtering and divided into p parts, which are electrically connected to the signal acquisition and control circuit component 104 through the p channel gating function chips 2 respectively.

[0015] Preferably, the signal acquisition and control circuit component 104 includes an A / D chip, a microprocessor and a communication interface circuit. The p channel selection function chips 2 are all connected to the analog signal input end of the A / D chip. The pressure signal is connected to the A / D chip through the channel selection function chip 2 in turn. The digital signal output end of the A / D chip is connected to the data input end of the microprocessor. The pressure detection result of the microprocessor is uploaded to the host computer through the communication interface circuit.

[0016] Preferably, the electrode protection layer 3 and the insulating isolation layer 6 are both made of high-boron glass materials.

[0017] Preferably, a transition layer is provided between the insulating isolation layer 6 and the kovar transfer layer 7, and the transition layer is a nickel-containing mixed material prepared by an electroplating process.

[0018] Preferably, the silicon cup 8 is manufactured by using a silicon wafer through a MEMS process.

[0019] Preferably, the channel gating function chip 2 is connected to the silicon cup wafer layer 5 through a WIRE BANDING process.

[0020] Beneficial effects of the invention: The invention provides a wafer-level array-type air pressure measurement device, which realizes high-density, small-volume, array-type air pressure measurement by performing array production and lead production on a silicon wafer, designing a porous isolation array-type glass support layer, applying wafer-level packaging technology, and combining special sintering transition layer production. Under the premise of the same size as the current 16-channel air pressure test device realized on the domestic process platform, the measurement channels are expanded to 128 channels.

[0021] It can achieve a more than 4-fold increase in measurement density at the same scale, avoid the operational difficulties and increased sealing uncertainty caused by independent fixed pieces and single-piece isolation seals, and also avoid the wire bonding process's vulnerability to damage and wire breakage during vibration and impact of the device.

[0022] The technical indicators achieved are as follows:

[0023] 1) Pressure measurement range: -100KPa~1000KPa; multiple sections are optional within the range.

[0024] 2) Measurement channels: Single-unit array 8×16=128 channels, which can be cascaded to 2048 channels.

[0025] 3) Measurement frequency: maximum 200KHz.

[0026] 4) Measurement accuracy: 0.05% FS.

[0027] 5) The unit dimensions are ≤40mm×80mm×30mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of a conventional multi-channel pressure test equipment. Figure 1 (a) is the appearance diagram, Figure 1 (b) is the schematic diagram. Figure 1 (c) is a physical picture of a single pressure unit;

[0029] Figure 2 It is a structural schematic diagram of a wafer-level array-type air pressure measurement device according to the present invention;

[0030] Figure 3 yes Figure 2 A partial enlarged view of

[0031] Figure 4 is a schematic diagram of the wafer-level air pressure measurement array structure;

[0032] Figure 5 yes Figure 4 A partial enlarged view of

[0033] Figure 6 This is a top view of the wafer-level gas pressure measurement array, without showing the electrode protection layer;

[0034] Figure 7 It is a schematic diagram of the electrode protection layer structure of the wafer-level gas pressure measurement array;

[0035] Figure 8 is a schematic diagram of the insulating isolation layer structure of a wafer-level gas pressure measurement array;

[0036] Fig. 9 is a schematic diagram of the Kovar transfer layer structure of the wafer-level air pressure measurement array;

[0037] Fig.10 The electrical block diagram of a wafer-level array-type air pressure measurement device described in the present invention. DETAILED DESCRIPTION

[0038] 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.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0040] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0041] Specific implementation method 1: The following is combined Figures 2 to 10 This embodiment describes a wafer-level array-type air pressure measurement device, see Figure 2 and Figure 3 , including a shell assembly, a wafer-level air pressure measurement array 100, a Kovar alloy pressure conduit 106 and a porous isolation array glass support layer 107. The wafer-level air pressure measurement array 100 is arranged in the shell assembly. The wafer-level air pressure measurement array 100 has m×n measurement channels, each measurement channel is connected to the outside through a Kovar alloy pressure conduit 106, and the m×n Kovar alloy pressure conduits 106 extend out of the shell assembly through the porous isolation array glass support layer 107.

[0042] Furthermore, it also includes a signal acquisition and control circuit component 104 and a connection 105, and the housing component includes a base 101 and a shell 102; the shell 102 is buckled on the base 101 to form a closed space, and the top plate of the shell 102 is provided with m×n array holes;

[0043] The signal acquisition and control circuit assembly 104 is mechanically fixed to the base 101 by means of fasteners 103 , and the wafer-level air pressure measurement array 100 is electrically connected to the signal acquisition and control circuit assembly 104 by means of wiring 105 ;

[0044] The top surface of the porous isolation array glass support layer 107 is fixed to the inner surface of the top plate of the housing 102 , and the bottom surface of the porous isolation array glass support layer 107 is fixed to the wafer-level air pressure measurement array 100 , and the holes are aligned.

[0045] See also Figures 4 to 6 The wafer-level pressure measurement array 100 includes a pressure-sensing capacitor 1, a channel gating function chip 2, an electrode protection layer 3, a noble metal electrode 4, a silicon wafer silicon cup wafer layer 5, an insulating isolation layer 6 and a Kovar transfer layer 7;

[0046] The silicon wafer layer 5 and the Kovar transfer layer 7 are bonded and connected via an insulating isolation layer 6; both the insulating isolation layer 6 and the Kovar transfer layer 7 have m×n array holes, and the measurement channels 9 are formed in one-to-one correspondence;

[0047] An m×n cavity array is provided on the upper surface of the silicon cup wafer layer 5, each cavity serves as a silicon cup 8, and each silicon cup 8 is connected to a measurement channel 9;

[0048] The lower surface of the bottom film of each silicon cup 8 is made of an m×n array of pressure-sensitive capacitors 1 by magnetron sputtering technology. A noble metal electrode 4 is arranged at each corner of each pressure-sensitive capacitor 1 to form a bridge structure. The differential capacitor structure is used to sense the pressure of the gas entering the measurement channel.

[0049] All the noble metal electrodes 4 are covered and protected by the electrode protection layer 3, and the electrode protection layer 3 is an m×n array hole structure, and the hole positions are used to accommodate the pressure-sensitive capacitor 1;

[0050] P channel gating function chips 2 are arranged on the lower surface of the silicon cup wafer layer 5, and m×n bridge leads are formed by magnetron sputtering and divided into p parts, which are electrically connected to the signal acquisition and control circuit component 104 through the p channel gating function chips 2 respectively.

[0051] See also Fig.10The signal acquisition and control circuit component 104 includes an A / D chip, a microprocessor and a communication interface circuit. The p channel selection function chips 2 are all connected to the analog signal input end of the A / D chip. The pressure signal is connected to the A / D chip through the channel selection function chip 2. The digital signal output end of the A / D chip is connected to the data input end of the microprocessor. The pressure detection result of the microprocessor is uploaded to the host computer through the communication interface circuit.

[0052] The electrode protection layer 3 and the insulating isolation layer 6 are both made of high-boron glass materials.

[0053] The silicon cup 8 is manufactured by using a silicon wafer through MEMS process.

[0054] The channel gating function chip 2 is connected to the silicon cup wafer layer 5 through a WIRE BANDING process.

[0055] Taking p=4 and m×n=8×16 as an example, the structure and principle of this embodiment are explained. The shell 102 is provided with a porous isolation array glass support layer 107, a Kovar transfer layer 7, an insulating isolation layer 6, and a silicon wafer silicon cup wafer layer 5 from top to bottom. The four layers are all 8×16 array structures, and the upper and lower position holes correspond to each other, forming 8×16 measurement channels 9, wherein the porous isolation array glass support layer 107 has the functions of insulation and bonding, the function of the Kovar transfer layer 7 is mechanical bearing, the function of the insulating isolation layer 6 is insulation, and the function of the silicon wafer silicon cup wafer layer 5 is to form a pressure-sensitive cavity for sensing the air pressure introduced by the measurement channel 9. The magnetron sputtering process is used to make sensitive capacitor electrodes on the silicon wafer on the silicon wafer silicon cup wafer layer 5, and a differential capacitor structure is used to sense pressure.

[0056] The present invention uses 4 channel gating function chips 2 to form 128 signals, greatly reducing the chip area. The present invention does not perform conventional operations such as chip cutting and lead welding, but directly forms leads by magnetron sputtering to achieve miniaturization.

[0057] By making arrays and leads on silicon wafers, a porous isolation array glass support layer was designed, wafer-level packaging technology was applied, and a special sintering transition layer was made. The pressure-sensitive part of the air pressure measurement was processed by MEMS technology on silicon wafers, using a beam-film structure to sense pressure, and sensitive capacitors were made on silicon wafers. Based on the capacitance effect, the air pressure-force-deformation-capacitance change was achieved to measure pressure. The multi-channel pressure signals were structurally isolated through an insulating isolation layer, and combined with the distribution setting of the silicon cup spacing, different air pressure signals can be measured without affecting each other.

[0058] In order to simplify and intuitively express the structure, the multi-layer structure shown in the figure does not express the process transition layer, but in the actual preparation process, each layer needs to be connected and prepared by transition layers, including bonding transition layers, adhesive transition layers, and stress transition layers. In terms of materials, the electrode protection layer and the insulating isolation layer are both made of high-boron glass materials, and other materials are standard process materials for MEMS processes. A transition layer is set between the insulating isolation layer 6 and the Kovar transfer layer 7. The transition layer is made of a nickel-containing mixed material prepared by an electroplating process.

[0059] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A wafer-level array-type air pressure measurement device, characterized in that: The invention comprises a shell component, a wafer-level air pressure measurement array (100), a Kovar alloy pressure conduit (106) and a porous isolation array type glass support layer (107). The wafer-level air pressure measurement array (100) is arranged in the shell component. The wafer-level air pressure measurement array (100) has m×n measurement channels, each of which is connected to the outside through a Kovar alloy pressure conduit (106). The m×n Kovar alloy pressure conduits (106) extend out of the shell component through the porous isolation array type glass support layer (107).

2. A wafer-level array-type air pressure measurement device according to claim 1, characterized in that: It also includes a signal acquisition and control circuit component (104) and a wiring (105), and the housing component includes a base (101) and a shell (102); the shell (102) is buckled on the base (101) to form a closed space, and the top plate of the shell (102) is provided with m×n array holes; The signal acquisition and control circuit assembly (104) is mechanically fixed to the base (101) via a fastener 103, and the wafer-level air pressure measurement array (100) is electrically connected to the signal acquisition and control circuit assembly (104) via a connection (105); The top surface of the porous isolation array glass support layer (107) is fixed to the inner surface of the top plate of the shell (102), the bottom surface of the porous isolation array glass support layer (107) is fixed together with the wafer-level air pressure measurement array (100), and the holes are arranged in alignment.

3. A wafer-level array-type air pressure measurement device according to claim 1 or 2, characterized in that: The wafer-level air pressure measurement array (100) comprises a pressure-sensitive capacitor (1), a channel gating function chip (2), an electrode protection layer (3), a noble metal electrode (4), a silicon chip silicon cup wafer layer (5), an insulating isolation layer (6) and a Kovar transfer layer (7); The silicon slice silicon cup wafer layer (5) and the Kovar transfer layer (7) are bonded and connected via an insulating isolation layer (6); The insulating isolation layer (6) and the Kovar transfer layer (7) both have m×n array holes, and form measurement channels (9) in one-to-one correspondence; An m×n cavity array is provided on the upper surface of the silicon cup wafer layer (5), each cavity serves as a silicon cup (8), and each silicon cup (8) is connected to a measurement channel (9); The lower surface of the bottom film of each silicon cup (8) is made of an m×n array-shaped pressure-sensing capacitor (1) by a magnetron sputtering process, and a noble metal electrode (4) is arranged at each of the four corners of each pressure-sensing capacitor (1) to form a bridge structure, and a differential capacitor structure is used to sense the pressure of the gas entering the measurement channel; All the noble metal electrodes (4) are covered and protected by an electrode protection layer (3), wherein the electrode protection layer (3) is an m×n array hole structure, and the holes are used to accommodate the pressure-sensitive capacitor (1); P channel gating function chips (2) are arranged on the lower surface of the silicon chip silicon cup wafer layer (5), and m×n bridge leads are formed by magnetron sputtering and divided into p parts, and are electrically connected to the signal acquisition and control circuit component (104) through the p channel gating function chips (2).

4. The wafer-level array-type air pressure measurement device according to claim 3, characterized in that: The signal acquisition and control circuit component (104) comprises an A / D chip, a microprocessor and a communication interface circuit. The p channel selection function chips (2) are all connected to the analog signal input end of the A / D chip. The pressure signal is connected to the A / D chip through the channel selection function chip (2) in turn. The digital signal output end of the A / D chip is connected to the data input end of the microprocessor. The pressure detection result of the microprocessor is uploaded to the host computer through the communication interface circuit.

5. The wafer-level array-type air pressure measurement device according to claim 3, characterized in that: The electrode protection layer (3) and the insulating isolation layer (6) are both made of high-boron glass materials.

6. The wafer-level array-type air pressure measurement device according to claim 3, characterized in that: A transition layer is provided between the insulating isolation layer (6) and the kovar transfer layer (7), and the transition layer is a nickel-containing mixed material prepared by an electroplating process.

7. The wafer-level array-type air pressure measurement device according to claim 3, characterized in that: The silicon cup (8) is prepared by using a silicon wafer through MEMS processing.

8. The wafer-level array-type air pressure measurement device according to claim 3, characterized in that: The channel gating function chip (2) is connected to the silicon cup wafer layer (5) through a WIRE BANDING process.

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