Pressure sensor module, method for manufacturing a pressure sensor module

Abstract

To provide a small and high-precision pressure sensor module that can be placed near a nozzle of a dispensing device and can measure minute pressure changes in suction and discharge.SOLUTION: A pressure sensor module includes: a channel substrate which includes a flow path and a branch path branched from the flow path; a semiconductor chip which has a piezoresistive element and is arranged so as to cover an opening of the branch path; and a cap which is bonded onto the semiconductor chip so as to cover the piezoresistive element and forms a cavity between the semiconductor chip and itself. In the cap or a junction between the cap and the semiconductor chip, a ventilation passage which communicates between the cavity and the outside is formed. In the normal direction, the shape of the opening of the branch path and the shape of the cavity are roughly similar.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to the structure of a pressure sensor module and a method for manufacturing the same, and particularly relates to an effective technique applicable to a pressure sensor module using a piezoresistive semiconductor element.

Background Art

[0002] A general pressure sensor is configured by forming or adhering a piezoresistive element or the like on a diaphragm made of a non-conductive material such as a silicon material or ceramics. The diaphragm is deformed by an external pressure of a liquid or gas, and the amount of change in the diaphragm is electrically measured as a resistance change by a Wheatstone bridge circuit or the like and converted into a pressure value to measure the pressure.

[0003] For example, in a manufacturing method of forming a diaphragm on a semiconductor substrate, a part of the surface opposite to the surface on which the detection element of the semiconductor substrate is formed is thinned by an anisotropic etching method or a grinding method of silicon to form a diaphragm. By etching or grinding a part of the semiconductor substrate, a certain measurement area can be formed. In addition, the sensing part of the semiconductor substrate on which a piezoresistive element or the like is formed is thinned to an arbitrary thickness by etching or grinding, and the diaphragm can be easily deformed when pressure is applied.

[0004] As the background art in this technical field, for example, there is a technique as disclosed in Patent Document 1. Patent Document 1 discloses "a method for manufacturing a semiconductor pressure sensor in which a substrate on which a strain-sensitive element is formed is thinned by etching or polishing".

[0005] In addition, Patent Document 2 discloses "an electronic component having excellent mechanical strength and weather resistance and a method for manufacturing the same".

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Incidentally, in dispensing devices that aspirate and dispense liquids used as specimens or samples, there is a need for a small, high-precision pressure sensor module that can be placed near the nozzle in order to grasp minute pressure changes in the aspiration and dispensing at the nozzle and to detect dispensing abnormalities and estimate the dispensing volume with high accuracy.

[0008] However, the technologies described in Patent Documents 1 and 2 above have the following problems, and there is room for improvement before they can be applied to dispensing devices.

[0009] In the semiconductor pressure sensor structure described in Patent Document 1, it is possible to increase the sensitivity of the strain-sensitive element when pressure is applied by thinning the silicon wafer on which the strain-sensitive element is formed by etching or polishing.

[0010] However, because it has a three-layer stacked structure consisting of a substrate for the cap, a silicon wafer on which the strain-sensitive element is formed, and a substrate for the base, two bonding points are required, increasing the bonding process and making the structure more complex.

[0011] Furthermore, a cavity space exists inside the cap, and a groove is formed on a part of the surface of the cap that bonds with the silicon wafer. Dicing connects the cavity space and the surrounding area. However, with two bonding points, the amount of misalignment is expected to be doubled, raising concerns that the chip dimensions must be increased to account for this misalignment if dicing is performed at the location of the ventilation groove.

[0012] Furthermore, the thickness of the three-layer laminated structure is not specified, and the method for forming the voids and ventilation channels on the cap substrate is only described as etching, without any description of the specific process used.

[0013] Furthermore, there is no description of how to electrically extract signals from the silicon wafer on which the strain-sensitive elements are formed, nor is there any description of how to attach the semiconductor pressure sensor for measuring pressure.

[0014] In the structure of Patent Document 2, the grooves in the cap substrate are formed by half-cutting during dicing, so it can be predicted that there will be a large variation in groove depth. When bonding with a wafer, the resin material may be held midway through its height, meaning that a bonding defect may occur under low load, and under high load, the resin material may be penetrated and reach the wafer surface where multiple electrode patterns are formed, making load control difficult.

[0015] Furthermore, because the hollow space in the joint is small in height and sealed, pressure fluctuations that cause deformation of the substrate will increase the pressure in the hollow space, hindering the deformation of the substrate. Therefore, it can be predicted that this method cannot be applied to pressure sensors.

[0016] Furthermore, the method for forming electrical wiring involves forming a metal film on an uneven surface and then performing wiring formation using photolithography. Therefore, when forming wiring on a surface with significant unevenness, it is necessary to form a thicker metal film to prevent disconnection at the corners, which is expected to present challenges in terms of productivity.

[0017] Therefore, the object of the present invention is to provide a small and highly accurate pressure sensor module that can be placed near the nozzle of a dispensing device and is capable of measuring minute pressure changes in suction and discharge, as well as a method for manufacturing the same. [Means for solving the problem]

[0018] To solve the above problems, the present invention provides a flow path substrate having a flow path and a branch path branched from the flow path inside; a semiconductor chip having a piezoresistive element and arranged to cover the opening of the branch path; and a cap bonded to the semiconductor chip so as to cover the piezoresistive element and forming a cavity between itself and the semiconductor chip, wherein a ventilation passage is formed in the cap or at the joint between the cap and the semiconductor chip to communicate the cavity with the outside, and the shape of the opening of the branch path and the shape of the cavity are substantially similar in the normal direction.

[0019] Furthermore, the present invention relates to a method for manufacturing a pressure sensor module having the above-described features, comprising: (a) a step of preparing a first substrate on which a plurality of piezoresistive elements are formed; (b) a step of forming a plurality of grooves of different depths on a second substrate by dry etching using a multilayer mask method; (c) a step of forming a resin material on the surface of the first substrate and performing patterning; (d) a step of positioning the first substrate and the second substrate using alignment marks on the first substrate and alignment marks on the second substrate, and joining the first substrate and the second substrate by heating and pressurizing; and (e) a step of combining a step of thinning the first substrate and the second substrate by grinding the surfaces opposite to the joining surfaces of the first substrate and the second substrate which have been integrated by step (d) to separate the integrated first substrate and the second substrate into individual pieces by performing dicing on the first substrate. [Effects of the Invention]

[0020] According to the present invention, a compact and highly accurate pressure sensor module that can be placed near the nozzle of a dispensing device and is capable of measuring minute pressure changes in suction and discharge, as well as a method for manufacturing the same, can be realized.

[0021] This can contribute to improving the accuracy and reliability of the dispensing device.

[0022] Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

Brief Description of the Drawings

[0023] [Figure 1A] It is a perspective view showing the structure of the pressure sensor module according to Example 1. [Figure 1B] It is a cross-sectional view showing the structure of the pressure sensor module according to Example 1. [Figure 2A] It is a perspective view showing the detailed structure of the pressure sensor according to Example 1. [Figure 2B] It is a cross-sectional view taken along the line A-A of FIG. 2A. [Figure 3] It is a diagram schematically showing the state of the pressure sensor when pressure is applied. [Figure 4A] It is a diagram showing the planar shape of the branch path 20. [Figure 4B] It is a diagram showing a modified example of FIG. 4A. [Figure 5A] It is a diagram showing the positional relationship among the branch path 20, the flow path substrate 25, and the cavity space 37. [Figure 5B] It is a diagram showing the positional relationship among the branch path 20, the flow path substrate 25, and the cavity space 37. [Figure 5C] It is a diagram showing the positional relationship among the branch path 20, the flow path substrate 25, and the cavity space 37. [Figure 6] It is a diagram showing the basic configuration of the dispensing device according to Example 1. [Figure 7] It is a diagram showing the internal state of the pipe 8 in the dispensing arm 16 immediately after liquid suction. [Figure 8] It is a diagram showing the process flow for manufacturing the cap substrate 24a for forming the cap 24. [Figure 9A] It is a diagram showing a part of the manufacturing process by wafer-level packaging. [Figure 9B] It is a diagram showing a part of the manufacturing process by wafer-level packaging. [Figure 10] It is a diagram showing the process flow for manufacturing a pressure sensor by wafer-level packaging. [Figure 11] This figure shows the process flow for manufacturing a pressure sensor by wafer-level packaging according to Example 2. [Figure 12A] This is a perspective view showing the detailed structure of the pressure sensor according to Example 3. [Figure 12B] Figure 12A is a cross-sectional view of BB. [Figure 13] This diagram shows the process flow for manufacturing the cap substrate 24b for forming the cap 24. [Figure 14] This diagram shows the process flow for manufacturing pressure sensors using wafer-level packaging. [Figure 15] This figure shows the process flow for manufacturing a pressure sensor by wafer-level packaging according to Example 4. [Figure 16] This is a perspective view showing an implementation example of the pressure sensor module according to Example 1. [Figure 17] This is a cross-sectional view showing the structure of the pressure sensor module according to Example 5. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described below with reference to the drawings. In each drawing, identical components are denoted by the same reference numerals, and detailed descriptions of overlapping parts are omitted. [Examples]

[0025] A pressure sensor module according to Embodiment 1 of the present invention and its manufacturing method will be described with reference to Figures 1A to 10 and Figure 16.

[0026] First, the schematic configuration of the pressure sensor module of this embodiment will be explained using Figures 1A and 1B. Figures 1A and 1B show the structure of the pressure sensor module 15A of this embodiment, and are perspective views and cross-sectional views, respectively.

[0027] Note that the longer side of the pressure sensor module 15A is shown as the Y direction, the shorter side as the X direction, and the height direction as the Z direction.

[0028] The flow channel substrate 25 has a flow channel 19 formed inside, and the flow channel inlet 19a and flow channel outlet 19b are provided with threaded portions (not shown). The flow channel 19 can be connected to the piping 8 of the dispensing device 1, which will be described later using Figure 7, via a fitting. In addition, a branch path 20 is provided inside the flow channel 19, branching toward the outer surface (Z direction) of the flow channel substrate 25, and a thin-film piezoresistive semiconductor chip 3 is positioned to block the end of the branch path 20.

[0029] Specifically, the piezoresistive semiconductor chip 3 is bonded (adhered) to the channel substrate 25 via an adhesive layer 18. Stainless steel is preferable for the channel substrate 25 due to its excellent corrosion resistance. Other metals with high corrosion resistance, such as aluminum or titanium, may also be used. Furthermore, resin materials such as acrylic may also be used. The adhesive layer 18 can be made from silver paste, silicone-based adhesive, epoxy-based adhesive, thermal diffusion bonding, thermosetting adhesive, UV addition adhesive, low-melting-point glass, etc.

[0030] Figures 2A and 2B show the detailed structure of the pressure sensor in this embodiment. Figure 2A is a perspective view showing the detailed structure of the pressure sensor in this embodiment, and Figure 2B is a cross-sectional view AA of Figure 2A.

[0031] Note that the longer side of the pressure sensor is denoted as the Y direction, the shorter side as the X direction, and the height direction as the Z direction.

[0032] The piezoresistive semiconductor chip 3 has a piezoresistive element 17 in the center and multiple electrodes 46 formed on the outer periphery of the chip, with a cap 24 positioned on top. The cap 24 has a cavity space 43 and a ventilation passage 36a formed therein and is bonded to the piezoresistive semiconductor chip 3 by a bonding layer 45. By applying a patternable photosensitive resin material to the bonding layer 45, any pattern can be formed. In addition, the electrodes 46 electrically connected to the piezoresistive element 17 may be arranged on one side of the piezoresistive semiconductor chip 3 or around its periphery.

[0033] The positional relationship between the planar shape of the branching path 20 and the planar shape of the cavity space 37 will be explained using Figures 3 to 5C.

[0034] Figure 3 schematically shows the state of the pressure sensor when pressure is applied, and shows the portion of the flow path substrate 25 above the branch path 20.

[0035] The cap 24 has a cavity space 37 inside and a ventilation passage 36a connecting the cavity space 37 to the outside. When, for example, water pressure 44 is applied to the branch passage 20, the central part of the piezoresistive semiconductor chip 3 deforms upward (in the Z direction) as shown by the dotted line (deformation region 51). The ventilation passage 36a is formed in the direction normal to the cavity space 37 of the cap 24.

[0036] Specifically, since the piezoresistive semiconductor chip 3 is fixed to the flow channel substrate 25 with an adhesive layer 18 around its periphery, only the unfixed central portion is displaced. The cavity space 37 formed in the cap 24 is a space that does not hinder the deformation of the piezoresistive semiconductor chip 3, and is formed as a large groove in the Z direction compared to the amount of displacement of the piezoresistive semiconductor chip 3. In addition, a ventilation passage 36a that communicates with the outside is formed to suppress the effect of increased internal pressure due to compression of the cavity space 37. Due to this deflection deformation, the piezoresistive element 17 senses the strain, converts it into a change in resistance value, and measures the pressure.

[0037] Figure 4A shows the plan view of the branch road 20. Figure 4B shows a modified example of Figure 4A.

[0038] As described above, when water pressure 44 is applied to the branching path 20, the piezoresistive semiconductor chip 3 deforms by bending. For this reason, as shown in Figure 4A, an elliptical shape is preferable for the planar shape of the branching path 20.

[0039] Furthermore, as shown in Figure 4B, the planar shape of the branching path 20 can also be rectangular. However, in this rectangular shape, there is a concern that stress will easily concentrate at the four corners of the rectangle when the piezoresistive semiconductor chip 3 undergoes deflection deformation. Therefore, it is preferable for the planar shape of the branching path 20 to be formed with curves without corners. For example, providing rounded corners (R-shaped) at the corners of the rectangle is effective.

[0040] On the other hand, since the present invention calculates the pressure value from the difference in displacement in the X and Y directions, it is difficult to apply to perfect circles and squares.

[0041] Furthermore, when joining the piezoresistive semiconductor chip 3 to the flow channel substrate 25, it is desirable to align them with high precision. Preferably, the piezoresistive element 17 of the piezoresistive semiconductor chip 3 is positioned in the center of the branch path 20, and the left-right length Y1 and the top-bottom length X1 are the same length.

[0042] Furthermore, in the case of the piezoresistive element 17, the piezoresistive semiconductor element 3 bends and deforms in response to pressure changes, and the change in resistance is measured by the difference in strain in the X and Y directions. Therefore, as shown in Figure 4A, it is preferable that the length in the X direction is shorter than the length in the Y direction, such as Y1 + Y1 > X1 + X1. Even in the case of a rectangular planar shape, as shown in Figure 4B, it is preferable that the length in the X direction is shorter than the length in the Y direction, such as Y2 + Y2 > X2 + X2.

[0043] Next, the positional relationship between the branching path 20, the flow path substrate 25, and the cavity space 37 will be explained using Figures 5A to 5C.

[0044] Note that the dimensions of the planar branching paths 20a shown in Figures 5A to 5C, and the distance X3 (joint width) from the edge of the flow path substrate 25 to each cavity space 37a, 37b, and 37c are all the same.

[0045] Figure 5A shows the case where the cavity space 37a is large relative to the shape of the branching path 20a, Figure 5B shows the case where the cavity space 37b is approximately the same shape as the branching path 20a, and Figure 5C shows the case where the cavity space 37c is small relative to the shape of the branching path 20a.

[0046] In the structure shown in Figure 5A, a large cavity space 37a can be formed, which does not hinder the bending deformation of the piezoresistive semiconductor chip 3. However, the overall dimensions of the flow channel substrate 25 become large, making miniaturization difficult. On the other hand, in the structure shown in Figure 5C, the overall dimensions of the flow channel substrate 25 are reduced, which is effective for miniaturization. However, it hinders the bending deformation of the piezoresistive semiconductor chip 3, thus reducing its function as a pressure sensor. Therefore, in the present invention, as shown in the structure shown in Figure 5B, the shape of the cavity space 37b is made substantially the same as the shape of the branching path 20a, thereby reducing the overall dimensions of the flow channel substrate 25 and creating a structure that does not hinder the bending deformation of the piezoresistive semiconductor chip 3.

[0047] In other words, by configuring the opening of the branching path 20a and the cavity space 37b to be approximately similar in the direction normal to the cavity space 37b, or when viewing the pressure sensor module 15A from above, a compact and highly accurate pressure sensor module can be realized.

[0048] Figure 6 shows the basic configuration of the dispensing device 1 equipped with the pressure sensor module 15A of the present invention.

[0049] The flow path system of the dispensing device 1 in this embodiment consists of a nozzle 2, a syringe pump 4, a solenoid valve 5, a gear pump 6, and a tank 7 for storing system water, with each component connected by piping 8. The syringe pump 4 consists of a container 9, a plunger 10, a ball screw 11, and a drive motor 12. The drive motor 12 is controlled by a control board 14, similar to the motors that drive the sample dispensing mechanism 13, etc. The dispensing arm 16 is equipped with the pressure sensor module 15A of the present invention. The dispensing arm 16 can rotate and move up and down to move to a position for aspirating and dispensing the liquid sample or specimen.

[0050] Figure 7 shows the internal state of the piping 8 inside the dispensing arm 16 immediately after liquid aspiration.

[0051] The piping 8 is filled with system water 21, which is water used to transmit syringe pressure. By transmitting pressure from the syringe pump 4, liquid 22 can be drawn in and discharged from the nozzle 2. The system water 21 is supplied from the tank 7.

[0052] When drawing liquid 22 from nozzle 2, the plunger 10 inside syringe pump 4 is pulled with solenoid valve 5 closed. Conversely, when discharging liquid 22 from nozzle 2, the plunger 10 inside syringe pump 4 is pushed into container 9 with solenoid valve 5 closed.

[0053] When aspirating a sample or liquid 22, to prevent the liquid 22 from mixing with the system water 21 in the piping 8, segmentation air 23 for segmentation at the nozzle 2 is aspirated first, and then the liquid 22 is aspirated. After the liquid 22 is discharged, the nozzle 2 is cleaned. During nozzle cleaning, cleaning water is applied to the outer wall of the nozzle 2, and at the same time, the system water 21 in the piping 8 is pushed out. To push out the system water 21 in the nozzle 2 during cleaning, the solenoid valve 5 is opened and the pressure of the gear pump 6 is used, so that the system water 21 is delivered at a higher pressure than when pushed out by the syringe pump 4.

[0054] To detect abnormalities such as clogging or dry suction of the nozzle 2 that may occur during dispensing, a pressure sensor module 15A is provided in a portion of the piping 8 within the dispensing arm 16. The pressure sensor module 15A monitors the pressure of the system water 21 and detects pressure changes that occur when abnormalities such as clogging or dry suction of the nozzle 2 occur.

[0055] As shown in Figure 7, in this embodiment, the pressure sensor module 15A is installed in the dispensing arm 16, which is as close to the nozzle 2 as possible, in order to sensitively detect pressure changes inside the nozzle 2. However, the installation location of the pressure sensor module 15A is not limited to inside the dispensing arm 16. For example, it may be installed on the side of the sample dispensing mechanism 13.

[0056] Next, we will explain the manufacturing method of a pressure sensor by wafer-level packaging, including the formation of a ventilation channel, using Figures 8 to 10.

[0057] Figure 8 shows the process flow for manufacturing the cap substrate 24a for forming the cap 24. Figure 8 shows cross-sectional views of each step from (a) to (i).

[0058] First, prepare the silicon wafer 30a as shown in step (a).

[0059] Next, in step (b), a thermal oxide film 31 is formed on the front and back surfaces of the silicon wafer 30a. The thermal oxide film 31 can be formed by supplying wet oxygen gas at high temperature to a large number of silicon wafers, which offers excellent productivity. However, the oxide film may also be formed by applying, for example, a sputtering apparatus. Before forming the thermal oxide film 31, alignment marks may be formed on the back surface of the silicon wafer 30a by photolithography and dry etching.

[0060] Next, in step (c), a resist pattern is formed on the surface of the silicon wafer 30a by photolithography (resist coating, exposure, development), etching of the thermal oxide film 31, and removal of the resist, thereby forming an opening 32 in the thermal oxide film 31.

[0061] Next, in step (d), the openings 32 are filled by photolithography, and a resist pattern 33 is formed so as to partially overlap with the thermal oxide film 31.

[0062] Subsequently, in step (e), the thermal oxide film 31 is patterned by etching using the resist pattern 33 as a mask. This completes the multilayer mask.

[0063] Next, in step (f), silicon dry etching is applied to form the first etching grooves 34a and 34b. By applying silicon dry etching, it is possible to form grooves that are not only straight but also curved in shape.

[0064] The etching grooves 34a and 34b are machined to the same depth, for example, about 270 μm. Etching groove 34b is an etching groove for forming the ventilation passage 36a.

[0065] Next, in step (g), the resist pattern 33 is removed. By removing the resist pattern 33, a new silicon surface is exposed.

[0066] Next, in step (h), dry etching of silicon is performed using the thermal oxide film 31 as a mask material. This forms second etching grooves 35a and 35b, and etching grooves 35c with different depths from etching grooves 35a and 35b on the silicon wafer 30a, thereby forming multi-stage grooves of varying depths.

[0067] Finally, in step (i), the thermal oxide film 31 is removed to complete the cap substrate 24a having different steps (etched grooves 35a, 35b, 35c). The cap substrate 24a can be formed on a 6-inch or 8-inch silicon wafer 30a.

[0068] Figures 9A and 9B show a portion of the manufacturing process using wafer-level packaging.

[0069] In the wafer-level packaging manufacturing method, as shown in Figure 9A, the side of the cap substrate 24a with the multi-stage steps 35 is placed downwards, and the side of the other piezoresistive semiconductor wafer 40 on which the piezoresistive semiconductor chip 3 is formed is placed upwards. After high-precision positioning using alignment marks 47a and 47b, the wafers are stacked as shown in Figure 9B.

[0070] The alignment marks 47a on the cap substrate 24a may be formed on the same side as the multi-stage step 35, or on the opposite side.

[0071] The detailed manufacturing method of the pressure sensor will be explained using Figure 10. Figure 10 is a diagram showing the process flow for manufacturing a pressure sensor by wafer-level packaging. Figure 10 shows cross-sectional views of each step from (a) to (g).

[0072] First, a piezoresistive semiconductor wafer 40 is prepared as shown in step (a). The piezoresistive semiconductor wafer 40 has multiple piezoresistive elements 17 and multiple electrodes 46 formed on it.

[0073] Next, in step (b), a resin material that will become the bonding layer 45 is formed on the surface on which the piezoresistive element 17 and the electrode 46 are formed. Preferably, a photosensitive resin material is used for the resin material 45, for example, a photosensitive film resist can be applied. If a photosensitive resin material is used, the resin can also be planarized and patterned by spin coating.

[0074] Next, in step (c), an arbitrary resin material pattern 45a is formed on the piezoresistive semiconductor wafer 40 by photolithography. Since the resin material is non-conductive, it is possible to insulate the cap substrate 24a from the piezoresistive semiconductor wafer 40.

[0075] Subsequently, in step (d), the cap substrate 24a is precisely aligned and stacked on the piezoresistive semiconductor wafer 40 using the method shown in Figures 9A and 9B. The steps 35 (etching grooves 35a, 35b, 35c) of the cap substrate 24a correspond to the etching grooves 35a, 35b, 35c in Figure 8.

[0076] By applying pressure and temperature during bonding, the piezoresistive semiconductor wafer 40 and the cap substrate 24a adhere closely together with the resin material pattern 45a acting as a bonding layer. The bonding conditions were a pressure of 1 MPa and a temperature of 300°C. At this time, the resin material shrinks due to the application of pressure and temperature. Therefore, the thickness of the bonding layer after bonding should be 50 μm or less, especially around 20 μm, so the resin material before bonding should be formed with a thickness that takes shrinkage into account.

[0077] Next, in step (e), a backgrind tape 41 is attached to the lower surface of the piezoresistive semiconductor wafer 40, and the upper surface of the cap substrate 24a is ground. In the grinding process, a #2000 grinding wheel is applied first to perform rough grinding, and then a finer grinding wheel of #5000 or higher is applied midway through the process. This allows the cap substrate 24a to be separated into multiple caps 24b. Furthermore, ventilation passages 36 can be formed simultaneously in each separated cap 24b. The cavity space 43 formed inside the cap 24b is connected to the outside through the ventilation passages 36.

[0078] Furthermore, the cap substrate 24a can also be thinned using grinding and chemical mechanical polishing (CMP). This method is highly productive because it minimizes variations in thickness and allows for the grinding of uniformly thick piezoresistive semiconductor elements at the wafer level. If a coarse grinding wheel, such as a #2000 grinding wheel, is used to complete the grinding process, chipping may occur at the corners. Therefore, the surface of the cap 24b after grinding needs to be finished with a fine-grit grinding wheel of #5000 or higher. The thickness of the cap 24b was processed to approximately 200 μm.

[0079] Next, in step (f), the lower surface of the piezoresistive semiconductor wafer 40 is fixed with a dicing tape 42, and then dicing is performed to form partial dicing grooves 39a (half-dicing grooves) in the piezoresistive semiconductor wafer 40. As a result, dicing grooves 39a are formed in the piezoresistive semiconductor wafer 40 both vertically and horizontally.

[0080] Finally, in step (g), a backgrind tape 41 is attached to the upper surface of the cap 24b, and the lower surface of the piezoresistive semiconductor wafer 40 is ground. The grinding method is the same as described above. This separates the wafer into a piezoresistive semiconductor chip 3 with the cap 24b attached. After this, the piezoresistive semiconductor chip 3 is picked up to complete the pressure sensor with a capped piezoresistive semiconductor chip.

[0081] The thickness of the piezoresistive semiconductor chip 3 is preferably 80 μm or less, and particularly good at around 50 μm. A thinner silicon layer allows for a wider deformation range in response to minute pressure fluctuations, thereby improving detection accuracy.

[0082] The electrodes 46 are formed outside the cap 24b, and the ventilation passages 36 that connect to the outside air are also formed in each individual piezoresistive semiconductor chip 3. Furthermore, the position of the ventilation passages 36 formed in the cavity space 43 of the cap 24b can be set at any position in the cavity space 43, and at least one can be formed in each cap 24b.

[0083] The diameter of the vents 36 can be set arbitrarily, but it is preferably 100 μm or less, and 20 μm or less is preferable. The smaller the pore diameter, the more effective it is at preventing the entry of foreign matter such as dust. In addition, since it is formed by dry etching, the shape of the vents 36 can also be set arbitrarily.

[0084] Furthermore, when the piezoresistive semiconductor chip 3 is thinned by thin-film processing, electrical leakage may occur depending on the structure of the piezoresistive element or the electrical conductivity of the silicon material. However, in the present invention, this can be addressed by forming a thin insulating film on the surface of the thinned piezoresistive semiconductor chip 3.

[0085] By applying this wafer-level packaging manufacturing method, the overall thickness of the pressure sensor can be reduced to approximately 300 μm, enabling the productive manufacturing of thin-film piezoresistive semiconductor chips with caps. Further thinning is possible by changing the thickness of the caps. The chip size achieved was approximately 2.5 mm square.

[0086] Next, an example of the implementation of the pressure sensor module of the present invention will be described using Figure 16. Figure 16 is a perspective view showing an example of the implementation of the pressure sensor module 15B. Figure 16 shows an example of electrical wiring to the piezoresistive semiconductor chip 3 mounted on the pressure sensor module 15B.

[0087] Note that the longer side of the pressure sensor module 15B is shown as the Y direction, the shorter side as the X direction, and the height direction as the Z direction.

[0088] The flow channel substrate 25 has a flow channel 19 (not shown) formed inside, and the flow channel inlet 19a and flow channel outlet 19b (not shown) are provided with threaded portions (not shown), and the flow channel 19 can be connected to the piping 8 of the dispensing device 1 shown in Figures 6 and 7 via a fitting. In addition, a branch path 20 (not shown) is provided inside the flow channel 19, branching toward the outer surface (Z direction) of the flow channel substrate 25, and a thin-film piezoresistive semiconductor chip 3 is placed so as to block the end of the branch path 20. The piezoresistive semiconductor chip 3 is bonded (adhered) to the flow channel substrate 25 via an adhesive layer 18.

[0089] Multiple electrode pads 46a are arranged on the piezoresistive semiconductor chip 3, and are connected by wires 49 to electrode pads 46b formed on a flexible substrate 48 for electrical wiring, which is supported by a frame 50.

[0090] Gold wire or aluminum wire can be used for wire 49. In addition, an anisotropic conductive film (ACF) or the like may be used for connection. A printed wiring board (PCB) may be used for the flexible circuit board 48 for electrical wiring.

[0091] When system water flows through the channel 19 (not shown) within the flow channel substrate 25, it flows into the branching channel 20 (not shown), and pressure is applied to the piezoresistive semiconductor chip 3. When pressure is applied, the piezoresistive semiconductor chip 3 deforms, and this deformation is detected as an electrical signal and transmitted to the flexible substrate 48, thereby allowing the pressure to be measured.

[0092] Thus, by applying a structure in which a thin-film piezoresistive semiconductor chip 3 is directly installed at the end of the branch path 20, the distance from the flow path 19 to the end of the branch path is short, which allows for accurate detection of pressure changes in the system water flowing through the flow path 19, and also has the advantage of enabling faster pressure detection.

[0093] In addition to piezoresistive elements, strain gauges, piezoelectric elements, and other methods may also be used for strain measurement. [Examples]

[0094] Referring to Figure 11, a method for manufacturing a pressure sensor module according to Embodiment 2 of the present invention will be described.

[0095] Figure 11 shows the process flow for manufacturing a pressure sensor by wafer-level packaging. Figure 11 shows cross-sectional views of each step from (a) to (g).

[0096] In the wafer-level packaging process, including the formation of a ventilation channel for the pressure sensor, a capped piezoresistive semiconductor chip can be realized even with a process different from that of Example 1 (Figure 10).

[0097] Steps (a) through (d) in Figure 11 are the same as steps (a) through (d) in Figure 10, and therefore, the repeated explanation will be omitted.

[0098] (e) In step (e), a backgrind tape 41 is attached to the upper surface of the cap substrate 24a, and the lower surface of the piezoresistive semiconductor wafer 40 is ground. This makes it possible to reduce the thickness of the piezoresistive semiconductor chip 3.

[0099] The thickness of the piezoresistive semiconductor chip 3 is preferably 80 μm or less, and particularly good at around 50 μm. A thinner silicon layer allows for a wider deformation range in response to minute pressure fluctuations, thereby improving detection accuracy.

[0100] In the grinding process described above, a #2000 grit grinding wheel is used first for rough grinding, and then a finer grit grinding wheel of #5000 or higher is used for further grinding.

[0101] Furthermore, the piezoresistive semiconductor wafer 40 can also be thinned using grinding and chemical mechanical polishing (CMP). This method is less prone to thickness variations, and allows for the grinding of uniformly thick piezoresistive semiconductor elements at the wafer level, resulting in excellent productivity.

[0102] Furthermore, when the piezoresistive semiconductor chip 3 is thinned by thin-film processing, electrical leakage may occur depending on the structure of the piezoresistive element or the electrical conductivity of the silicon material. However, in the present invention, this can be addressed by forming a thin insulating film on the surface of the thinned piezoresistive semiconductor chip 3.

[0103] Next, in step (f), a backgrind tape 41 is attached to the lower surface of the thinned piezoresistive semiconductor wafer 40, and the upper surface of the cap substrate 24a is ground. The grinding method is the same as described above, and the thickness of the cap 24b was processed to about 200 μm. This allows the cap substrate 24a to be separated into multiple caps 24b. Furthermore, ventilation passages 36 can be formed simultaneously in each separated cap 24b. The cavity space 43 formed inside the cap 24b is connected to the outside through the ventilation passages 36.

[0104] Finally, in step (g), the lower surface of the piezoresistive semiconductor wafer 40 is fixed with a dicing tape 42, and then dicing is performed to form dicing grooves 39b (full-cut dicing grooves) on the piezoresistive semiconductor wafer 40. Dicing grooves 39b are formed on the piezoresistive semiconductor wafer 40 both vertically and horizontally. This allows the wafer to be separated into a piezoresistive semiconductor chip 3 with a cap 24b. After this, the piezoresistive semiconductor chip 3 is picked up to complete the pressure sensor with a capped piezoresistive semiconductor chip.

[0105] The electrodes 46 are formed outside the cap 24b, and the ventilation passages 36 that connect to the outside air are also formed in each individual piezoresistive semiconductor chip 3. Furthermore, the position of the ventilation passages 36 formed in the cavity space 43 of the cap 24b can be set at any position in the cavity space 43, and at least one can be formed in each cap 24b.

[0106] The diameter of the vents 36 can be set arbitrarily, but it is preferably 100 μm or less, and 20 μm or less is preferable. The smaller the pore diameter, the more effective it is at preventing the entry of foreign matter such as dust. In addition, since it is formed by dry etching, the shape of the vents 36 can also be set arbitrarily.

[0107] Thus, by applying a manufacturing method using wafer-level packaging different from that of Example 1 (Figure 10), the overall thickness of the pressure sensor can be processed to approximately 300 μm, enabling the productive manufacturing of thin-film piezoresistive semiconductor chips with caps. Further thinning is possible by changing the thickness of the caps. The chip size achieved was approximately 2.5 mm square. [Examples]

[0108] Referring to Figures 12A to 14, a pressure sensor module according to Embodiment 3 of the present invention and its manufacturing method will be described.

[0109] Figure 12A is a perspective view showing the detailed structure of the pressure sensor in this embodiment, and Figure 12B is a cross-sectional view of BB in Figure 12A. Note that the long side direction of the pressure sensor is the Y direction, the short side direction is the X direction, and the height direction is the Z direction.

[0110] The piezoresistive semiconductor chip 3 has a piezoresistive element 17 in the center and multiple electrodes 46 formed on the outer periphery of the chip, with a cap 24 positioned on top. The piezoresistive semiconductor chip 3 and the cap 24 are joined by a bonding layer 45. By applying a patternable photosensitive resin material to the bonding layer 45, any pattern can be formed. Therefore, the ventilation passage 36b connecting the cavity space 43 to the outside can be formed inside the bonding layer 45 by patterning.

[0111] Next, a method for manufacturing a pressure sensor by wafer-level packaging, including the formation of a ventilation channel, will be described using Figures 13 and 14.

[0112] Figure 13 shows the process flow for manufacturing the cap substrate 24a for forming the cap 24. Figure 13 shows cross-sectional views of each step from (a) to (i).

[0113] First, prepare the silicon wafer 30b as shown in step (a).

[0114] Next, in step (b), a thermal oxide film 31 is formed on the front and back surfaces of the silicon wafer 30b. At this time, alignment marks may be formed in advance on the back surface of the silicon wafer 30b by photolithography and dry etching.

[0115] Next, in step (c), a resist pattern is formed on the surface of the silicon wafer 30b by photolithography (resist coating, exposure, development), etching of the thermal oxide film 31, and removal of the resist, thereby forming openings 32 in the thermal oxide film 31.

[0116] Next, in step (d), the openings 32 are filled by photolithography, and a resist pattern 33 is formed so as to partially overlap with the thermal oxide film 31.

[0117] Subsequently, in step (e), the thermal oxide film 31 is patterned by etching using the resist pattern 33 as a mask. This completes the multilayer mask.

[0118] Next, in step (f), a silicon dry etching process is applied to form the first etching groove 34a. By applying a silicon dry etching process, it becomes possible to form grooves that are not only straight but also curved in shape.

[0119] The etching groove 34a is machined to a depth of approximately 280 μm, for example.

[0120] Next, in step (g), the resist pattern 33 is removed. By removing the resist pattern 33, a new silicon surface is exposed.

[0121] Next, in step (h), dry etching of silicon is performed using the thermal oxide film 31 as a mask material. This creates a second etching groove 34b and an etching groove 34c with a different depth from the etching groove 34b on the silicon wafer 30b, thereby forming a multi-stage groove with varying depths.

[0122] Finally, in step (i), the thermal oxide film 31 is removed to complete the cap substrate 24b having different steps (etched grooves 35d, 35e). The cap substrate 24b can be formed on a 6-inch or 8-inch silicon wafer 30b. Furthermore, by combining multiple mask materials, it is possible to form even more grooves with different steps.

[0123] The detailed manufacturing method of the pressure sensor will be explained using Figure 14. Figure 14 is a diagram showing the process flow for manufacturing a pressure sensor by wafer-level packaging. Figure 14 shows cross-sectional views of each step from (a) to (g).

[0124] First, a piezoresistive semiconductor wafer 40 is prepared as shown in step (a). The piezoresistive semiconductor wafer 40 has multiple piezoresistive elements 17 and multiple electrodes 46 formed on it.

[0125] Next, in step (b), a resin material that will become the bonding layer 45 is formed on the surface on which the piezoresistive element 17 and the electrode 46 are formed. Preferably, a photosensitive resin material is used for the resin material 45, for example, a photosensitive film resist can be applied. If a photosensitive resin material is used, the resin can also be planarized and patterned by spin coating.

[0126] Next, in step (c), an arbitrary resin material pattern 45a is formed on the piezoresistive semiconductor wafer 40 by photolithography. At this time, an opening is formed in a part of the resin material pattern 45a. By forming the opening by patterning, a ventilation passage 36b can be formed in the subsequent separation process. Since the ventilation passage can be formed by patterning in this way, it is possible to form one or more ventilation passages 36b for one cap.

[0127] Subsequently, in step (d), the cap substrate 24b is precisely aligned and stacked on the piezoresistive semiconductor wafer 40 using the method shown in Figures 9A and 9B. The steps 35 (etching grooves 35e, 35d) of the cap substrate 24b correspond to the etching grooves 35e, 35d in Figure 13.

[0128] By applying pressure and temperature during bonding, the piezoresistive semiconductor wafer 40 and the cap substrate 24b adhere closely together with the resin material pattern 45a acting as a bonding layer. The bonding conditions were a pressure of 1 MPa and a temperature of 300°C. At this time, the resin material shrinks due to the application of pressure and temperature. Therefore, the thickness of the bonding layer after bonding should be 50 μm or less, especially around 20 μm, so the resin material before bonding should be formed with a thickness that takes shrinkage into account.

[0129] Next, in step (e), a backgrind tape 41 is attached to the lower surface of the piezoresistive semiconductor wafer 40, and the upper surface of the cap substrate 24b is ground. The thickness of the cap was processed to approximately 200 μm. In the grinding process, a #2000 grinding wheel is applied first for rough grinding, and then a finer grinding wheel of #5000 or higher is applied. This allows the cap substrate 24b to be separated into multiple caps 24c. Furthermore, ventilation passages 36b can be formed simultaneously in each separated cap 24c.

[0130] Furthermore, the cap substrate 24b can also be thinned using grinding and chemical mechanical polishing (CMP). This method is highly productive because it minimizes variations in thickness and allows for the grinding of uniformly thick piezoresistive semiconductor elements at the wafer level. If a coarse grinding wheel, such as a #2000 grinding wheel, is used to complete the grinding process, chipping may occur at the corners. Therefore, the surface of the cap 24c after grinding must be finished with a fine-grit grinding wheel of #5000 or higher. At this time, the cavity space 43 formed inside the cap 24c is connected to the outside through the ventilation passage 36b.

[0131] Next, in step (f), the lower surface of the piezoresistive semiconductor wafer 40 is fixed with a dicing tape 42, and then dicing is performed to form partial dicing grooves 39a (half-dicing grooves) in the piezoresistive semiconductor wafer 40. As a result, dicing grooves 39a are formed in the piezoresistive semiconductor wafer 40 both vertically and horizontally.

[0132] Finally, in step (g), a backgrind tape 41 is attached to the upper surface of the cap 24c, and the lower surface of the piezoresistive semiconductor wafer 40 is ground. The grinding method is the same as described above. This separates the wafer from the piezoresistive semiconductor chip 3 with the cap 24c attached. After this, the piezoresistive semiconductor chip 3 is picked up to complete the pressure sensor with a capped piezoresistive semiconductor chip.

[0133] The thickness of the piezoresistive semiconductor chip 3 is preferably 80 μm or less, and particularly good at around 50 μm. A thinner silicon layer allows for a wider deformation range in response to minute pressure fluctuations, thereby improving detection accuracy.

[0134] Furthermore, when the piezoresistive semiconductor chip 3 is thinned by thin-film processing, electrical leakage may occur depending on the structure of the piezoresistive element or the electrical conductivity of the silicon material. However, in the present invention, this can be addressed by forming a thin-film insulator on the surface of the thinned piezoresistive semiconductor chip 3.

[0135] The electrode 46 is formed outside the cap 24c, and the ventilation passage 36b, which connects to the outside air, is also formed on each individual piezoresistive semiconductor chip 3.

[0136] Furthermore, the ventilation passage 36b can be freely positioned as it can be formed by patterning the resin material that forms the bonding layer. The width of the ventilation passage 36b can also be set arbitrarily, but preferably it is 30 μm or less in width, as it expands by several microns due to the pressure and temperature during bonding. The narrower the width, the more effective it is in preventing the entry of foreign matter such as dust. In addition, the shape of the ventilation passage 36b can also be a structure in which the line is bent or a structure formed by a curve.

[0137] Thus, by using a method different from Examples 1 and 2, namely by providing a ventilation passage at the joint, the overall thickness of the pressure sensor can be processed to approximately 300 μm without increasing the process, and a thin-film piezoresistive semiconductor chip with a cap can be manufactured with high productivity. Further thinning is possible by changing the thickness of the cap. The chip size was achieved to approximately 2.2 mm square. [Examples]

[0138] Referring to Figure 15, a method for manufacturing a pressure sensor module according to Embodiment 4 of the present invention will be described.

[0139] Figure 15 shows the process flow for manufacturing a pressure sensor by wafer-level packaging. Figure 15 shows cross-sectional views of each step from (a) to (g).

[0140] In the wafer-level packaging method process, including the formation of a ventilation channel for the pressure sensor, a capped piezoresistive semiconductor chip can be realized even with a process different from that of Example 3 (Figure 14).

[0141] Steps (a) through (d) in Figure 15 are the same as steps (a) through (d) in Figure 14, and therefore, the repeated explanation will be omitted.

[0142] (e) In step (e), a backgrind tape 41 is attached to the upper surface of the cap substrate 24b, and the lower surface of the piezoresistive semiconductor wafer 40 is ground. This makes it possible to reduce the thickness of the piezoresistive semiconductor chip 3.

[0143] The thickness of the piezoresistive semiconductor chip 3 is preferably 100 μm or less, and particularly good at around 50 μm. A thinner silicon layer allows for a wider deformation range in response to minute pressure fluctuations, thereby improving detection accuracy.

[0144] In the grinding process described above, a #2000 grit grinding wheel is used first for rough grinding, and then a finer grit grinding wheel of #5000 or higher is used for further grinding.

[0145] Furthermore, the piezoresistive semiconductor wafer 40 can also be thinned using grinding and chemical mechanical polishing (CMP). This method is less prone to thickness variations, and allows for the grinding of uniformly thick piezoresistive semiconductor elements at the wafer level, resulting in excellent productivity.

[0146] Furthermore, when the piezoresistive semiconductor chip 3 is thinned by thin-film processing, electrical leakage may occur depending on the structure of the piezoresistive element or the electrical conductivity of the silicon material. However, in the present invention, this can be addressed by forming a thin insulating film on the surface of the thinned piezoresistive semiconductor chip 3.

[0147] Next, in step (f), a backgrind tape 41 is attached to the lower surface of the thinned piezoresistive semiconductor wafer 40, and the upper surface of the cap substrate 24b is ground. The grinding method is the same as described above, and the thickness of the cap 24b was processed to about 180 μm. This allows the cap substrate 24b to be separated into multiple caps 24d. Furthermore, ventilation passages 36b can be formed simultaneously in each separated cap 24d. The cavity space 43 formed inside the cap 24d is connected to the outside through the ventilation passages 36b.

[0148] Finally, in step (g), the lower surface of the piezoresistive semiconductor wafer 40 is fixed with a dicing tape 42, and then dicing is performed to form dicing grooves 39b (full-cut dicing grooves) on the piezoresistive semiconductor wafer 40. Dicing grooves 39b are formed on the piezoresistive semiconductor wafer 40 both vertically and horizontally. This allows the wafer to be separated into a piezoresistive semiconductor chip 3 with a cap 24d. After this, the piezoresistive semiconductor chip 3 is picked up to complete the pressure sensor of the piezoresistive semiconductor chip with a cap.

[0149] The electrode 46 is formed outside the cap 24d, and the ventilation passage 36b, which connects to the outside air, is also formed on each individual piezoresistive semiconductor chip 3.

[0150] Furthermore, the ventilation passage 36b can be freely positioned as it can be formed by patterning the resin material that forms the bonding layer. The width of the ventilation passage 36b can also be set arbitrarily, but preferably it is 30 μm or less in width, as it expands by several microns due to the pressure and temperature during bonding. The narrower the width, the more effective it is in preventing the entry of foreign matter such as dust. In addition, the shape of the ventilation passage 36b can also be a structure in which the line is bent or a structure formed by a curve. [Examples]

[0151] Referring to Figure 17, a pressure sensor module according to Embodiment 5 of the present invention will be described. Figure 17 is a cross-sectional view showing the structure of the pressure sensor module of this embodiment.

[0152] Examples 1 to 4 described the structure and manufacturing process of the pressure sensor structure of the present invention. As a method to improve the bonding strength of the pressure sensor placed on the flow channel substrate 25, a method can be applied in which a thin film 29 made of the same material as the piezoresistive semiconductor chip 3 is formed around the outlet of the branch path 20 of the flow channel substrate 25.

[0153] For example, if the thin film 29 is not formed, the bonding interface between the stainless steel material of the channel substrate 25 and the silicon material of the piezoresistive semiconductor chip 3 will be formed by the adhesive layer 18.

[0154] By forming a thin film 29 on stainless steel, the interface of the adhesive layer 18 only needs to consider adhesion to the same silicon, and the material of the adhesive to be applied to the adhesive layer 18 can be easily selected.

[0155] Furthermore, the thickness of the thin film 29 formed around the outlet of the branch path 20 of the flow channel substrate 25 can improve bonding strength if it is between 100 nm and 300 nm thick. It is possible to form it thicker, but if it is formed too thick, the stress on the thin film itself may cause delamination from the stainless steel.

[0156] In this invention, the location and formation method of the ventilation passage can be selected, and two manufacturing processes can be selected, thus broadening the range of manufacturing methods and allowing for greater flexibility in selection.

[0157] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0158] 1…Dispensing device, 2…Nozzle, 3…Piezoresistive semiconductor chip, 4…Syringe pump, 5…Solenoid valve, 6…Gear pump, 7…Tank, 8…Piping, 9…Container, 10…Plunger, 11…Ball screw, 12…Drive motor, 13…Sample dispensing mechanism, 14…Control board, 15A,15B…Pressure sensor module, 16…Dispensing arm, 17…Piezoresistive element, 18…Adhesive layer, 19…Flow channel, 19a…Flow channel inlet, 19b…Flow channel outlet, 20,20a…Branch, 21…System water, 22…Liquid, 23…Segmented air, 24…Cap, 24a,24b,24c,24d…Cap substrate, 25…Flow channel substrate, 29…Thin film, 30a,30b…Silicon Wafer, 31...thermal oxide film, 32...opening, 33...resist pattern, 34a,34b,34c,35a,35b,35c,35d,35e...etched grooves, 35...step, 36,36a,36b...ventilation channels, 37,37a,37b,37c,43...cavity space, 39a,39b...dicing grooves, 40...piezoresistive semiconductor wafer, 41...backgrind tape, 42...dicing tape, 44...water pressure, 45...bonding layer (resin material), 45a...resin material pattern, 46...electrode, 46a,46b...electrode pads, 47a,47b...alignment marks, 48...flexible substrate, 49...wire, 50...stand, 51...deformation region.

Claims

1. A flow channel substrate having a flow channel and a branch path branched from the flow channel, A semiconductor chip having a piezoresistive element and positioned to cover the opening of the branch path, The piezoresistive element is bonded to the semiconductor chip so as to cover it, and a cap is formed between the semiconductor chip and the element, A ventilation passage is formed in the cap or the junction between the cap and the semiconductor chip, which connects the cavity to the outside. A pressure sensor module characterized in that, in the normal direction, the shape of the opening of the branching path and the shape of the cavity are substantially similar in shape.

2. A pressure sensor module according to claim 1, A pressure sensor module characterized in that, when viewed from above, the shape of the opening of the branching path and the shape of the cavity are substantially similar in shape.

3. A pressure sensor module according to claim 1, The pressure sensor module is characterized in that the shape of the cavity has different lengths in the long side direction and the short side direction of the pressure sensor module, and the lengths are symmetrical with respect to the center point of the cavity.

4. A pressure sensor module according to claim 1, The pressure sensor module is characterized in that the ventilation passage is formed in the direction normal to the cavity of the cap.

5. A pressure sensor module according to claim 1, The cap and the semiconductor chip are joined together via a resin material. The pressure sensor module is characterized in that the ventilation passage is formed in the resin material.

6. A pressure sensor module according to claim 1, The semiconductor chip is bonded to the channel substrate via an adhesive layer. A pressure sensor module characterized in that a film made of the same material as the semiconductor chip is formed on the bonding surface of the flow channel substrate with the semiconductor chip.

7. A method for manufacturing a pressure sensor module according to any one of claims 1 to 6, (a) A step of preparing a first substrate on which a plurality of piezoresistive elements are formed, (b) A step of forming multiple grooves of different depths on a second substrate by dry etching using a multilayer mask method, (c) A step of forming a resin material on the surface of the first substrate and performing patterning, (d) A step of positioning the first substrate and the second substrate using the alignment marks of the first substrate and the alignment marks of the second substrate, and then joining the first substrate and the second substrate by heating and pressurizing, (e) A step of forming the first substrate and the second substrate, which have been integrated by step (d), into individual pieces by combining a step of grinding the surfaces opposite to the bonding surfaces of the first substrate and the second substrate, which have been integrated by step (d), to thin the first substrate and the second substrate, and a step of performing a dicing process on the first substrate, A method for manufacturing a pressure sensor module, characterized by having the following features. Veil structure

8. A method for manufacturing a pressure sensor module according to claim 7, A method for manufacturing a pressure sensor module, characterized by grinding the surfaces of the integrated first substrate and second substrate opposite to their respective bonding surfaces with a grinding wheel of a finer grit than #5000, thereby reducing the thickness of the integrated first substrate and second substrate to 300 μm or less.

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