Pressure sensor module and method for manufacturing pressure sensor module

Abstract

The invention provides a small and high-precision pressure sensor module which can be arranged near a nozzle of a dispensing device and can measure small pressure change of suction discharge. The present invention is characterized by being provided with: a flow path substrate having, in the interior thereof, a flow path and a branch path branching from the flow path; a semiconductor chip that has a piezoresistive element and is disposed so as to cover the opening of the branch path; and a lid body which is bonded to the semiconductor chip so as to cover the piezoresistive element, and which forms a cavity between the lid body and the semiconductor chip, and in which an air passage that connects the cavity and the outside is formed in the lid body or in the bonding part between the lid body and the semiconductor chip, the shape of the opening of the branch path is substantially similar to the shape of the cavity.

Description

Technical Field

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

[0002] A general pressure sensor is configured by forming or bonding a piezoresistive element or the like on a diaphragm made of a non-conductive material such as silicon or ceramic. The diaphragm is deformed by an external pressure of a liquid or a gas, and the change amount of the diaphragm is measured electrically as a resistance change by using 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 of the semiconductor substrate on the side opposite to the surface on which the detection element is formed is thinned by using an anisotropic etching method or a grinding method of silicon to form a diaphragm. By etching and grinding a part of the semiconductor substrate, a certain measurement area can be formed. In addition, the sensing detection part of the semiconductor substrate on which a piezoresistive element or the like is formed is thinned to an arbitrary thickness by etching and grinding, and the diaphragm can be easily deformed when pressure is applied.

[0004] As a 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 grinding".

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

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-332746

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-186761 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] However, in a dispensing device that aspirates and ejects a liquid serving as a detection object or a sample, in order to grasp minute pressure changes in the aspiration and ejection in the nozzle, detect dispensing abnormalities with high precision, and estimate the dispensing amount, a small and highly accurate pressure sensor module that can be disposed near the nozzle is required.

[0012] However, the following problems exist in the technologies of Patent Document 1 and Patent Document 2 above, and there is room for improvement for application to a dispensing device.

[0013] In the structure of the semiconductor pressure sensor of Patent Document 1 above, the silicon wafer on which the strain-sensitive element is formed is thinned by etching or grinding, so that the sensitivity of the strain-sensitive element can be increased when pressure is applied.

[0014] However, since it is a three-layer stacked structure of the cover substrate, the silicon wafer on which the strain-sensitive element is formed, and the pedestal substrate, two joints are required, the joining process increases and the structure is complex.

[0015] Moreover, there is a cavity space inside the cover, and a groove is formed in a part of the surface of the cover that is joined to the silicon wafer. By cutting, a structure is formed in which the cavity space communicates with the peripheral part. However, if there are two joints, the expected position offset amount also becomes twice as large, and there is a concern that the chip size must be increased in order to cut at the position of the groove in the air passage and consider the position offset.

[0016] Also, the thickness of the three-layer stacked structure is not described, and only the formation method of the voids formed in the cover substrate and the air passage is etching, but the specific process of formation is not described.

[0017] Furthermore, there is no description of how to electrically lead out a signal from the silicon wafer on which the strain-sensitive element is formed, nor is there a description related to the installation method of the semiconductor pressure sensor for measuring pressure.

[0018] In the structure of Patent Document 2, since the groove of the cover substrate is formed by semi-cutting using cutting, it can be predicted that the deviation of the groove depth becomes large. In the case of joining with the wafer, it is considered to be held in the middle of the height of the resin material, that is, in the case of low load, a joining defective part is generated, and in the case of high load, it penetrates the resin material and reaches the surface of the wafer on which a plurality of electrode patterns are formed, and it can be predicted that load control is difficult.

[0019] Moreover, since the height of the space of the joined hollow part is small and airtight, in the pressure change accompanying the deformation of the substrate, the pressure in the hollow part increases and hinders the deformation of the substrate, so it can be predicted that it cannot be applied to a pressure sensor.

[0020] Also, in the method of forming the electrical wiring, a metal film is formed on the uneven surface, and the wiring formation is carried out by photolithography. Therefore, in the wiring formation on a strongly uneven surface, in order to prevent disconnection at the corners, it is necessary to form the metal film thickly, and it can be predicted that there is a problem in productivity.

[0021] Therefore, an object of the present invention is to provide a small and highly accurate pressure sensor module that can be disposed near a nozzle of a dispensing device and can measure minute pressure changes during suction and ejection, and a method for manufacturing the same.

[0022] Means for Solving the Problem

[0023] In order to solve the above problems, the present invention is characterized by including: 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 disposed so as to cover an opening of the branch path; and a lid body joined to the semiconductor chip so as to cover the piezoresistive element and forming a cavity between the lid body and the semiconductor chip. An air passage communicating the cavity with the outside is formed in the lid body or a joint portion between the lid body and the semiconductor chip, and in the normal direction, the shape of the opening of the branch path and the shape of the cavity are substantially similar shapes.

[0024] Moreover, the present invention is a method for manufacturing a pressure sensor module having the above characteristics, and is characterized by including the following steps: (a) preparing a first substrate formed with a plurality of piezoresistive elements; (b) using a multi-layer mask method to form a plurality of grooves with different depths in a second substrate by dry etching; (c) forming a resin material on the surface of the first substrate and performing patterning; (d) performing positioning using alignment marks on the first substrate and alignment marks on the second substrate, heating and pressing to join the first substrate and the second substrate; and (e) combining a step of thinning the first substrate and the second substrate by grinding the surfaces on the opposite sides of the joint surfaces of the first substrate and the second substrate that have become integrated through the step (d), and a step of cutting the first substrate, and singulating the integrated first substrate and second substrate.

[0025] Effects of the Invention are as follows.

[0026] According to the present invention, it is possible to realize a small and highly accurate pressure sensor module that can be disposed near a nozzle of a dispensing device and can measure minute pressure changes during suction and ejection, and a method for manufacturing the same.

[0027] Thereby, it is possible to contribute to an improvement in the accuracy and reliability of the dispensing device.

[0028] Through the following description of the embodiments, problems, structures, and effects other than the above will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1A It is a perspective view showing the structure of the pressure sensor module of Embodiment 1.

[0030] Figure 1B is a cross-sectional view showing the structure of the pressure sensor module of Embodiment 1.

[0031] Figure 2A is a perspective view showing the detailed structure of the pressure sensor of Embodiment 1.

[0032] Figure 2B is Figure 2A A - A cross-sectional view of

[0033] Figure 3 is a diagram schematically showing the state of the pressure sensor when pressure is applied.

[0034] Figure 4A is a diagram showing the planar shape of the branch path 20.

[0035] Figure 4B is showing Figure 4A a modified example of

[0036] Figure 5A is a diagram showing the positional relationship among the branch path 20, the flow path substrate 25, and the cavity space 37.

[0037] Figure 5B is a diagram showing the positional relationship among the branch path 20, the flow path substrate 25, and the cavity space 37.

[0038] Figure 5C is a diagram showing the positional relationship among the branch path 20, the flow path substrate 25, and the cavity space 37.

[0039] Figure 6 is a diagram showing the basic structure of the dispensing device of Embodiment 1.

[0040] Figure 7 is a diagram showing the internal state of the pipe 8 in the dispensing arm 16 just after sucking the liquid.

[0041] Figure 8 is a diagram showing the process flow for manufacturing the cover substrate 24a for forming the cover 24.

[0042] Figure 9A is a diagram showing a part of the manufacturing process of the wafer - level package.

[0043] Figure 9B is a diagram showing a part of the manufacturing process of the wafer - level package.

[0044] Figure 10 is a diagram showing the process flow for manufacturing the pressure sensor using the wafer - level package.

[0045] Figure 11FIG. is a diagram showing a process flow for manufacturing a pressure sensor using the wafer-level package of Example 2.

[0046] Figure 12A FIG. is a perspective view showing the detailed structure of the pressure sensor of Example 3.

[0047] Figure 12B is Figure 12A sectional view taken along line B-B of

[0048] Figure 13 FIG. is a diagram showing a process flow for manufacturing a cover substrate 24b for forming a cover 24.

[0049] Figure 14 FIG. is a diagram showing a process flow for manufacturing a pressure sensor using a wafer-level package.

[0050] Figure 15 FIG. is a diagram showing a process flow for manufacturing a pressure sensor using the wafer-level package of Example 4.

[0051] Figure 16 FIG. is a perspective view showing an installation example of the pressure sensor module of Example 1.

[0052] Figure 17 FIG. is a sectional view showing the structure of the pressure sensor module of Example 5. DETAILED DESCRIPTION

[0053] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to the same structures in the respective drawings, and detailed descriptions of overlapping portions are omitted.

[0054] Example 1

[0055] Refer to Figures 1A to 10 and Figure 16 to describe the pressure sensor module and its manufacturing method according to Example 1 of the present invention.

[0056] First, use Figure 1A and Figure 1B to briefly describe the structure of the pressure sensor module of this embodiment. Figure 1A and Figure 1B are diagrams showing the structure of the pressure sensor module 15A of this embodiment, showing a perspective view and a sectional view, respectively.

[0057] In addition, the long side direction of the pressure sensor module 15A is shown as the Y direction, the short side direction is shown as the X direction, and the height direction is shown as the Z direction.

[0058] A flow path 19 is formed inside a flow path substrate 25, and threaded portions (not shown) are provided at a flow path inlet 19a and a flow path outlet 19b. The flow path 19 can be connected via a joint to a pipe 8 of a dispensing device 1 described below. Further, a branch path 20 branching toward the outer surface (Z direction) of the flow path substrate 25 is provided inside the flow path 19, and a piezoelectric resistance type semiconductor chip 3 with a thin film is disposed so as to block the end portion of the branch path 20. Figure 7 And the pipe 8 of the dispensing device 1 described below can be connected to the flow path 19 via a joint. Further, a branch path 20 branching toward the outer surface (Z direction) of the flow path substrate 25 is provided inside the flow path 19, and a piezoelectric resistance type semiconductor chip 3 with a thin film is disposed so as to block the end portion of the branch path 20.

[0059] Specifically, the piezoelectric resistance type semiconductor chip 3 is joined (bonded) to the flow path substrate 25 via an adhesive layer 18. From the viewpoint of excellent corrosion resistance, the material of the flow path substrate 25 is preferably stainless steel. In addition, as long as it is a metal with high corrosion resistance, metals such as aluminum and titanium can also be used. Further, a resin material such as acrylic can also be used. As the material of the adhesive layer 18, silver paste, a silicon-based adhesive, an epoxy-based adhesive, thermal diffusion bonding, a thermosetting adhesive, a UV addition type adhesive, a low melting point glass, etc. can be used.

[0060] Figure 2A and Figure 2B show the detailed structure of the pressure sensor of this embodiment. Figure 2A is a perspective view showing the detailed structure of the pressure sensor of this embodiment, Figure 2B is Figure 2A a sectional view taken along line A-A of

[0061] In addition, the long side direction of the pressure sensor is shown as the Y direction, the short side direction is shown as the X direction, and the height direction is shown as the Z direction.

[0062] In the piezoelectric resistance type semiconductor chip 3, a piezoelectric resistance element 17 is formed at the central portion, a plurality of electrodes 46 are formed at the outer peripheral portion of the chip, and a cover body 24 is disposed on the upper portion. A cavity space 43 and a ventilation path 36a are formed in the cover body 24 and joined to the piezoelectric resistance type semiconductor chip 3 by a joining layer 45. As the material of the joining layer 45, a photosensitive resin material capable of forming a pattern is used, and an arbitrary pattern can be formed. Further, the electrodes 46 electrically connected to the piezoelectric resistance element 17 may be disposed on one side of the piezoelectric resistance type semiconductor chip 3 or around it.

[0063] Use Figures 3 to 5C to describe the positional relationship between the planar shape of the branch path 20 and the planar shape of the cavity space 37.

[0064] Figure 3 is a diagram schematically showing the state of the pressure sensor when pressure is applied, showing a portion above the branch path 20 of the flow path substrate 25.

[0065] Inside the cover body 24, a cavity space 37 is formed, and a ventilation path 36a is formed in a manner that connects the cavity space 37 to the outside. When water pressure 44 is applied to the branch path 20, for example, the central portion of the piezoresistive semiconductor chip 3 flexes upward (in the Z direction) as shown by the dashed line (deformation region 51). The ventilation path 36a is formed along the normal direction within the cavity space 37 of the cover body 24.

[0066] Specifically, since the periphery of the piezoresistive semiconductor chip 3 is fixed to the flow path substrate 25 by the adhesive layer 18, only the non-fixed central portion is displaced. The cavity space 37 formed in the cover body 24 is a space for not hindering the deformation of the piezoresistive semiconductor chip 3, and is formed as a groove that is larger in the Z direction compared to the displacement amount of the piezoresistive semiconductor chip 3. Also, in order to suppress the influence of the increase in the internal pressure of the cavity space 37 due to compression, a ventilation path 36a communicating with the outside is formed. Due to this flexural deformation, the piezoresistive element 17 detects the strain and converts it into a change in resistance value to measure the pressure.

[0067] Figure 4A It is a diagram showing the planar shape of the branch path 20. Figure 4B It is shown Figure 4A a modified example of

[0068] As described above, when water pressure 44 is applied to the branch path 20, the piezoresistive semiconductor chip 3 flexes and deforms. Therefore, as Figure 4A shown, the planar shape of the branch path 20 can be an elliptical shape.

[0069] Also, as Figure 4B shown, the planar shape of the branch path 20 can also be applied to a rectangular shape. In this rectangular shape, when the piezoresistive semiconductor chip 3 flexes and deforms, there is a concern that stress is likely to concentrate on the four corners of the rectangle. Therefore, the planar shape of the branch path 20 can be formed by a curve without corners. For example, it is effective to provide a circular arc portion (R portion) at the corners of the rectangle.

[0070] On the other hand, in the present invention, since the pressure value is converted based on the displacement difference between the X direction and the Y direction, it is difficult to apply a perfect circle and a square.

[0071] Furthermore, when the piezoresistive semiconductor chip 3 is joined to the flow path substrate 25, alignment can be performed with high precision. The piezoresistive element 17 of the piezoresistive semiconductor chip 3 is preferably disposed at the central portion of the branch path 20, and the left - right length Y1 and the up - down length X1 are preferably the same length.

[0072] Also, in the piezoresistive element 17, the piezoresistive semiconductor element 3 flexes and deforms due to a pressure change, and the change in resistance value is measured from the strain difference between the X direction and the Y direction. Therefore, asFigure 4A As shown, preferably the length in the X direction is shorter than the length in the Y direction, such as Y1 + Y1 > X1 + X1. In the case of a rectangular planar shape, it is also as Figure 4B shown, preferably the length in the X direction is shorter than the length in the Y direction, such as Y2 + Y2 > X2 + X2.

[0073] Next, use Figures 5A to 5C to illustrate the positional relationship among the branch path 20, the flow path substrate 25, and the cavity space 37.

[0074] In addition, Figures 5A to 5C the size of the branch path 20a in the planar direction shown, and the distances X3 (bonding widths) from the end of the flow path substrate 25 to the respective cavity spaces 37a, 37b, 37c are all of the same size.

[0075] Figure 5A shows a case where the cavity space 37a is larger than the shape of the branch path 20a, Figure 5B shows a case where the cavity space 37b is substantially the same as the shape of the branch path 20a, Figure 5C shows a case where the cavity space 37c is smaller than the shape of the branch path 20a.

[0076] In Figure 5A the structure, the cavity space 37a can be formed relatively large, which does not hinder the flexural deformation of the piezoresistive semiconductor chip 3, but the overall size of the flow path substrate 25 becomes large, making it difficult to achieve miniaturization. On the other hand, in Figure 5C the structure, the overall size of the flow path substrate 25 becomes small, which is effective for miniaturization, but it hinders the flexural deformation of the piezoresistive semiconductor chip 3, thus reducing the function as a pressure sensor. Therefore, in the present invention, as in Figure 5B the structure, the shape of the cavity space 37b is made substantially the same as the shape of the branch path 20a, which can miniaturize the overall size of the flow path substrate 25 and is configured not to hinder the flexural deformation of the piezoresistive semiconductor chip 3.

[0077] In other words, it is configured such that in the normal direction of the cavity space 37b or when viewing the pressure sensor module 15A from above, the shape of the opening of the branch path 20a and the shape of the cavity space 37b become substantially similar shapes, thereby enabling a small and highly accurate pressure sensor module to be realized.

[0078] Figure 6 is a diagram showing the basic structure of the dispensing device 1 equipped with the pressure sensor module 15A of the present invention.

[0079] The flow path system of the dispensing device 1 in this embodiment is composed of a nozzle 2, an injection pump 4, a solenoid valve 5, a gear pump 6, and a tank 7 for storing system water. Each component is connected by a pipe 8. Further, the injection pump 4 is composed 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 in the same manner as the motor for driving the sample dispensing mechanism 13 etc. The pressure sensor module 15A of the present invention is provided within the dispensing arm 16. The dispensing arm 16 moves to the position for sucking and ejecting the liquid serving as the test body and the specimen, and thus can perform rotational and vertical movements.

[0080] Figure 7 FIG. is a diagram showing the internal state of the pipe 8 within the dispensing arm 16 immediately after sucking the liquid.

[0081] The pipe 8 is filled with the system water 21 for syringe pressure transmission, which transmits the pressure of the injection pump 4, and enables sucking and ejecting the liquid 22 from the nozzle 2. The system water 21 is supplied from the tank 7.

[0082] When sucking the liquid 22 from the nozzle 2, the plunger 10 within the injection pump 4 is pulled while the solenoid valve 5 is closed. Conversely, when ejecting the liquid 22 from the nozzle 2, the plunger 10 within the injection pump 4 is pressed into the container 9 while the solenoid valve 5 is closed.

[0083] When sucking the liquid 22 serving as the test body and the specimen, the dispensing air 23 for segmentation by the nozzle 2 is sucked in such a manner that the liquid 22 does not mix with the system water 21 within the pipe 8, and then the liquid 22 is sucked. Further, after ejecting the liquid 22, the nozzle 2 is cleaned. In the cleaning of the nozzle 2, while bringing the cleaning water into contact with the outer wall of the nozzle 2, the system water 21 within the pipe 8 is extruded. In the extrusion of the system water 21 within the nozzle 2 during cleaning, the solenoid valve 5 is opened and the pressure of the gear pump 6 is utilized, so that the system water 21 is sent out at a pressure higher than when extruded by the injection pump 4.

[0084] In order to detect abnormalities such as blockage and air suction of the nozzle 2 that may occur during the dispensing operation, a pressure sensor module 15A is provided in a part of the pipe 8 within the dispensing arm 16. The pressure sensor module 15A monitors the pressure of the system water 21 and detects the pressure change that occurs when abnormalities such as blockage and air suction of the nozzle 2 occur.

[0085] As Figure 7 shown, in this embodiment, in order to sensitively capture the pressure change within the nozzle 2, the pressure sensor module 15A is provided within the dispensing arm 16 at a position as close as possible to the nozzle 2, but the installation position of the pressure sensor module 15A is not limited to within the dispensing arm 16. For example, it may also be provided on the side of the sample dispensing mechanism 13.

[0086] Next, use Figures 8 to 10, a manufacturing method of a pressure sensor using wafer-level packaging including the formation of a ventilation path will be described.

[0087] Figure 8 It is a diagram showing the process flow of manufacturing a cover substrate 24a for forming a cover body 24. Figure 8 Cross-sectional views of each process from process (a) to process (i) are shown.

[0088] First, as shown in process (a), a silicon wafer 30a is prepared.

[0089] Next, in process (b), a thermal oxide film 31 is formed on the front and back surfaces of the silicon wafer 30a. Since the thermal oxide film 31 can be formed on a large number of silicon wafers by supplying wet oxygen at a high temperature, the productivity is excellent. However, in addition, for example, a sputtering device can also be used to form the oxide film. In addition, before forming the thermal oxide film 31, alignment marks can be formed on the back side of the silicon wafer 30a by photolithography and dry etching.

[0090] Next, in process (c), each process of resist pattern formation (resist coating, exposure, development), etching of the thermal oxide film 31, and resist removal based on photolithography is performed on the surface of the silicon wafer 30a, and an opening 32 is formed in the thermal oxide film 31.

[0091] Next, in process (d), a resist pattern 33 is formed by photolithography so as to fill the opening 32 and partially overlap with the thermal oxide film 31.

[0092] After that, in process (e), using the resist pattern 33 as a mask, the thermal oxide film 31 is patterned by etching. Thus, a multi-layer mask is completed.

[0093] Next, in process (f), first etching grooves 34a and 34b are formed by applying dry etching of silicon. By applying dry etching of silicon, not only a linear shape but also a groove with a curved shape in the planar shape can be formed.

[0094] In addition, the etching grooves 34a and 34b are processed to the same depth, for example, about 270 μm. The etching groove 34b is an etching groove for forming the ventilation path 36a.

[0095] Next, in process (g), the resist pattern 33 is removed. By removing the resist pattern 33, a new silicon surface is exposed.

[0096] Next, in process (h), using the thermal oxide film 31 as a mask material, dry etching of silicon is performed. Thus, second etching grooves 35a and 35b and an etching groove 35c having a depth different from the depths of the etching grooves 35a and 35b are formed in the silicon wafer 30a, and multi-stage grooves with different depths can be formed.

[0097] Finally, in step (i), by removing the thermal oxide film 31, the lid substrate 24a with different steps (etching grooves 35a, 35b, 35c) is completed. In addition, the lid substrate 24a can be formed from a silicon wafer 30a with a size of 6 inches or 8 inches.

[0098] Figure 9A and Figure 9B shows a part of the manufacturing process of the wafer-level package.

[0099] In the manufacturing method of the wafer-level package, as Figure 9A shown, the surface of the lid substrate 24a with multiple steps 35 is arranged facing downwards, and the surface of another piezoresistive semiconductor wafer 40 on which the piezoresistive semiconductor chip 3 is formed is arranged facing upwards. Alignment marks 47a and 47b are used for highly accurate positioning, and then as Figure 9B shown, they are laminated.

[0100] In addition, the alignment mark 47a of the lid substrate 24a can be formed on the same surface as the surface with multiple steps 35, or can be formed on the opposite surface.

[0101] Use Figure 10 to illustrate the detailed manufacturing method of the pressure sensor. Figure 10 is a diagram showing the process flow of manufacturing a pressure sensor using a wafer-level package. Figure 10 The cross-sectional views of each step from step (a) to step (g) are shown therein.

[0102] First, as shown in step (a), a piezoresistive semiconductor wafer 40 is prepared. In addition, a plurality of piezoresistive elements 17 and a plurality of electrodes 46 are formed on the piezoresistive semiconductor wafer 40.

[0103] Next, in step (b), a resin material that becomes the bonding layer 45 is formed on the surface on which the piezoresistive elements 17 and the electrodes 46 are formed. The resin material 45 is preferably a photosensitive resin material, for example, a photosensitive thin-film resist can be applied. And if it is a photosensitive resin material, the resin can also be made flat by spin coating for patterning.

[0104] Next, in step (c), an arbitrary resin material pattern 45a is formed on the piezoresistive semiconductor wafer 40 by photolithography. Since the resin material has no conductivity, insulation between the lid substrate 24a and the piezoresistive semiconductor wafer 40 can be achieved.

[0105] After that, in step (d), using Figure 9A and Figure 9BThe method shown positions and stacks the cover substrate 24a with high precision on the piezoresistive semiconductor wafer 40. Further, the steps 35 (etching grooves 35a, 35b, 35c) of the cover substrate 24a correspond to Figure 8 the etching grooves 35a, 35b, 35c.

[0106] During bonding, pressure and temperature are applied, and the piezoresistive semiconductor wafer 40 and the cover substrate 24a are closely adhered with the resin material pattern 45a as the bonding layer. Further, the bonding conditions are implemented under a pressure of 1 MPa and a temperature of 300°C. At this time, the resin material shrinks due to the applied pressure and temperature. Therefore, the resin material before bonding is formed in advance with a thickness taking into account the shrinkage amount so that the thickness of the bonding layer after bonding is 50 μm or less, particularly about 20 μm.

[0107] Next, in the (e) process, a back grinding tape 41 is pasted on the lower surface side of the piezoresistive semiconductor wafer 40, and grinding is performed on the upper surface side of the cover substrate 24a. In the grinding, first, rough grinding is performed using a #2000 grinding wheel, and then, from the middle, a finer grinding wheel of #5000 or more is used for grinding. Thereby, the cover substrate 24a can be separated into a plurality of covers 24b. Further, an air passage 36 can be formed simultaneously in each of the separated covers 24b. The cavity space 43 formed in the cover 24b is connected to the outside through the air passage 36.

[0108] Further, in the method for thinning the cover substrate 24a, thinning can be achieved even by using grinding and chemical mechanical polishing (CMP: Chemical Mechanical Polishing). In this method, it is difficult to generate thickness deviations, and grinding of piezoresistive semiconductor elements with a uniform thickness can be performed at the wafer level, so the productivity is excellent. If grinding is performed until the end using a coarse grinding wheel, for example, a #2000 grinding wheel, chips are generated at the corners, so the surface of the cover 24b after grinding needs to be finish-machined using a finer grinding wheel of #5000 or more. Further, the thickness of the cover 24b is processed to be about 200 μm.

[0109] Next, in the (f) process, after fixing the lower surface side of the piezoresistive semiconductor wafer 40 with a dicing tape 42, dicing is performed to form a dicing groove 39a (semi-dicing groove) in the piezoresistive semiconductor wafer 40 halfway. Thereby, dicing grooves 39a are formed longitudinally and transversely in the piezoresistive semiconductor wafer 40.

[0110] Finally, in step (g), a back grinding tape 41 is pasted on the upper surface side of the lid 24b, and grinding is performed on the lower surface side of the piezoresistive semiconductor wafer 40. The grinding method is the same as the above-described method. Thus, the piezoresistive semiconductor chip 3 with the lid 24b can be separated from the wafer state. Thereafter, by picking up the piezoresistive semiconductor chip 3, the pressure sensor of the piezoresistive semiconductor chip with the lid is completed.

[0111] In addition, the thickness of the piezoresistive semiconductor chip 3 is preferably 80 μm or less, and particularly preferably about 50 μm. If the thickness of silicon becomes thinner, the deformation region can be expanded for minute pressure changes, and the detection accuracy can be improved.

[0112] The electrode 46 is formed outside the lid 24b, and the air vent 36 connected to the external air is also formed in each piezoresistive semiconductor chip 3. And the position of the air vent 36 formed in the cavity space 43 of the lid 24b can be set at any position in the cavity space 43, and at least one or more can be formed in each lid 24b.

[0113] The aperture diameter of the air vent 36 can also be arbitrarily set, but is preferably 100 μm or less, and most preferably 20 μm or less. There is an effect that the smaller the aperture diameter, the more effectively foreign matters such as dust can be prevented from entering. And since it is formed by dry etching, the shape of the air vent 36 can also be arbitrarily set.

[0114] In addition, in the case where the piezoresistive semiconductor chip 3 is made thinner by thinning processing, an electric leakage may occur due to the structure of the piezoresistive element or the conductivity of the silicon material. However, in the present invention, this can be dealt with by forming a thin film insulator on the surface of the thinned piezoresistive semiconductor chip 3.

[0115] In this way, by applying the manufacturing method of wafer-level packaging, the thickness of the entire pressure sensor can be processed to about 300 μm, and the piezoresistive semiconductor chip with a lid and a thin film can be manufactured with good productivity. By changing the thickness of the lid, further thinning can be achieved. In addition, the chip size can be realized at about 2.5 mm square.

[0116] Next, Figure 16 An installation example of the pressure sensor module of the present invention will be described. Figure 16 FIG. is a perspective view showing an installation example of the pressure sensor module 15B. Figure 16 FIG. shows an example of electrical wiring for the piezoresistive semiconductor chip 3 mounted on the pressure sensor module 15B.

[0117] In addition, the long side direction of the pressure sensor module 15B is shown as the Y direction, the short side direction is shown as the X direction, and the height direction is shown as the Z direction.

[0118] A flow path 19 (not shown) is formed inside a flow path substrate 25, and threaded portions (not shown) are provided at a flow path inlet 19a and a flow path outlet 19b. The flow path 19 can be connected to a pipe 8 of a dispensing device 1 shown in Figure 6 and Figure 7 via a joint. Further, a branch path 20 (not shown) that branches toward the outer surface (Z direction) of the flow path substrate 25 is provided inside the flow path 19, and a thin-film piezoresistive semiconductor chip 3 is disposed so as to block the end portion of the branch path 20. The piezoresistive semiconductor chip 3 is joined (bonded) to the flow path substrate 25 via an adhesive layer 18.

[0119] A plurality of electrode pads 46a are provided on the piezoresistive semiconductor chip 3 and are connected to electrode pads 46b of a flexible substrate 48 for electrical wiring supported by a stage 50 by wires 49.

[0120] In addition, the wires 49 can be gold wires or aluminum wires. Alternatively, an anisotropic conductive film (ACF: Anisotropic Conductive Film) or the like can be used for connection. Further, the flexible substrate 48 for electrical wiring can be a printed circuit board (PCB: Printed Wiring Board).

[0121] When system water flows in the flow path 19 (not shown) inside the flow path substrate 25, it flows into the branch path 20 (not shown), and pressure is applied to the piezoresistive semiconductor chip 3. When pressure is applied, the piezoresistive semiconductor chip 3 deforms, which is detected as an electrical signal and transmitted to the flexible substrate 48, so that the pressure can be measured.

[0122] Thus, by adopting a structure in which the thin-film piezoresistive semiconductor chip 3 is directly provided at the end portion of the branch path 20, since the distance from the flow path 19 to the end portion of the branch path is short, there are advantages that the pressure change of the system water flowing in the flow path 19 can be detected with high accuracy and the speed of detecting the pressure is increased.

[0123] In addition, as a strain measurement method, in addition to piezoresistive elements, strain gauges, piezoelectric elements, etc. can also be used.

[0124] Example 2

[0125] Refer to Figure 11 to describe a method for manufacturing a pressure sensor module according to Example 2 of the present invention.

[0126] Figure 11 is a diagram showing a process flow for manufacturing a pressure sensor using wafer-level packaging. Figure 11Cross-sectional views of each process from process (a) to process (g) are shown.

[0127] In the process of a wafer-level packaging method including the formation of an air passage including a pressure sensor, even in a process different from that of Example 1 ( Figure 10 ), a piezoelectric resistor type semiconductor chip with a cover can be realized.

[0128] Figure 11 The processes (a) to (d) of Figure 10 are the same as the processes (a) to (d) of

[0129] and repeated descriptions are omitted.

[0130] In process (e), a back grinding tape 41 is pasted on the upper surface side of the cover substrate 24a, and grinding is performed on the lower surface side of the piezoelectric resistor type semiconductor wafer 40. Thus, the thickness of the piezoelectric resistor type semiconductor chip 3 can be processed to be thinner.

[0131] In the above grinding process, first, rough grinding is performed using a #2000 grinding wheel, and then, from the middle, a finer grinding wheel of #5000 or more is used for grinding.

[0132] In addition, in the thinning process of the piezoelectric resistor type semiconductor wafer 40, thinning can be achieved even by applying grinding and chemical mechanical polishing (CMP: Chemical Mechanical Polishing). In this method, it is difficult to generate thickness deviation, and grinding can be performed on a piezoelectric resistor type semiconductor element with a uniform thickness at the wafer level, so the productivity is excellent.

[0133] In addition, when the piezoelectric resistor type semiconductor chip 3 is thinned by the thinning process, it is assumed that electric leakage may occur due to the structure of the piezoelectric resistor element or the 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 piezoelectric resistor type semiconductor chip 3.

[0134] Next, in process (f), a back grinding tape 41 is pasted on the lower surface side of the thinned piezoelectric resistor type semiconductor wafer 40, and grinding is performed on the upper surface side of the cover substrate 24a. In addition, the grinding method is the same as the above method, and the thickness of the cover 24b is processed to be about 200 μm. Thus, the cover substrate 24a can be separated into a plurality of covers 24b. Furthermore, air passages 36 can be formed simultaneously in each of the separated covers 24b. The cavity space 43 formed in the cover 24b is connected to the outside through the air passages 36.

[0135] Finally, in step (g), after the lower surface side of the piezoresistive semiconductor wafer 40 is fixed with the dicing tape 42, dicing is performed to form dicing grooves 39b (full dicing grooves) in the piezoresistive semiconductor wafer 40. The dicing grooves 39b are formed longitudinally and transversely in the piezoresistive semiconductor wafer 40. Thereby, it is possible to separate from the wafer state into the piezoresistive semiconductor chips 3 with the lid bodies 24b. Thereafter, by picking up the piezoresistive semiconductor chips 3, the pressure sensors of the piezoresistive semiconductor chips with the lid bodies are completed.

[0136] The electrodes 46 are formed outside the lid bodies 24b, and the air vents 36 connected to the external air are also formed in each of the piezoresistive semiconductor chips 3. And the position of the air vents 36 formed in the cavity space 43 of the lid bodies 24b can be set at any position in the cavity space 43, and at least one or more can be formed in each lid body 24b.

[0137] The aperture diameter of the air vents 36 can also be arbitrarily set, but it is preferably 100 μm or less, and can be 20 μm or less. There is an effect that the smaller the aperture diameter, the more effectively it can prevent foreign matters such as dust from entering. And since it is formed by dry etching, the shape of the air vents 36 can also be arbitrarily set.

[0138] Thus, by applying a manufacturing method of wafer-level packaging different from that of Embodiment 1 ( Figure 10 ), the overall thickness of the pressure sensor can be processed to about 300 μm, and the piezoresistive semiconductor chips with the lid bodies can be manufactured with good productivity. By changing the thickness of the lid bodies, further thinning can be achieved. In addition, the chip size can be realized at about 2.5 mm square.

[0139] Embodiment 3

[0140] Refer to Figures 12A to 14 to describe the pressure sensor module and its manufacturing method according to Embodiment 3 of the present invention.

[0141] Figure 12A is a perspective view showing the detailed structure of the pressure sensor of this embodiment, Figure 12B is Figure 12A 's sectional view taken along line B-B. In addition, the long side direction of the pressure sensor is shown as the Y direction, the short side direction is shown as the X direction, and the height direction is shown as the Z direction.

[0142] In the piezoresistive semiconductor chip 3, a piezoresistive element 17 is formed in the central portion, a plurality of electrodes 46 are formed in the outer peripheral portion of the chip, and a lid 24 is disposed on the upper portion. The piezoresistive semiconductor chip 3 and the lid 24 are joined by a bonding layer 45. As the material of the bonding layer 45, a photosensitive resin material capable of patterning is applied, and any pattern can be formed. Therefore, an air passage 36b that connects the cavity space 43 to the outside can be formed inside the bonding layer 45 by patterning.

[0143] Next, use Figure 13 and Figure 14 to describe a manufacturing method of a pressure sensor by wafer-level packaging including the formation of the air passage.

[0144] Figure 13 is a diagram showing a process flow for manufacturing a lid substrate 24a for forming the lid 24. Figure 13 Cross-sectional views of each process from process (a) to process (i) are shown.

[0145] First, as shown in process (a), a silicon wafer 30b is prepared.

[0146] Next, in process (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 on the back side of the silicon wafer 30b in advance by photolithography and dry etching.

[0147] Next, in process (c), resist patterning (resist coating, exposure, development), etching of the thermal oxide film 31, and resist removal are performed on the surface of the silicon wafer 30b by photolithography, and an opening 32 is formed in the thermal oxide film 31.

[0148] Next, in process (d), a resist pattern 33 is formed by photolithography so as to fill the opening 32 and partially overlap with the thermal oxide film 31.

[0149] After that, in process (e), the thermal oxide film 31 is patterned by etching using the resist pattern 33 as a mask. Thus, a multi-layer mask is completed.

[0150] Next, in process (f), a first etching groove 34a is formed by applying dry etching of silicon. By applying dry etching of silicon, not only a linear shape but also a groove having a curved shape in a planar shape can be formed.

[0151] In addition, the etching groove 34a is processed to a depth of about 280 μm, for example.

[0152] Next, in process (g), the resist pattern 33 is removed. The resist pattern 33 is removed to expose a new silicon surface.

[0153] Next, in step (h), using the thermal oxide film 31 as a mask material, dry etching of silicon is performed. As a result, a second etching groove 34b and an etching groove 34c having a depth different from that of the etching groove 34b are formed in the silicon wafer 30b, and multi-stage grooves having different depths can be formed.

[0154] Finally, in step (i), the thermal oxide film 31 is removed to complete the cover substrate 24b having different steps (etching grooves 35d, 35e). In addition, the cover substrate 24b can be formed from a 6-inch or 8-inch silicon wafer 30b. And by combining multiple mask materials, grooves with more different steps can be further formed.

[0155] Use Figure 14 To describe in detail the manufacturing method of the pressure sensor. Figure 14 FIG. is a diagram showing a process flow for manufacturing a pressure sensor using wafer-level packaging. Figure 14 Cross-sectional views of each step from step (a) to step (g) are shown.

[0156] First, as shown in step (a), a piezoresistive semiconductor wafer 40 is prepared. In addition, a plurality of piezoresistive elements 17 and a plurality of electrodes 46 are formed in the piezoresistive semiconductor wafer 40.

[0157] Next, in step (b), a resin material that becomes the bonding layer 45 is formed on the surface on which the piezoresistive element 17 and the electrode 46 are formed. The resin material 45 is preferably a photosensitive resin material, for example, a photosensitive thin film resist can be applied. And if it is a photosensitive resin material, the resin can also be made flat by spin coating for patterning.

[0158] 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 through patterning, an air passage 36b can be formed in the subsequent separation process. In this way, an air passage can be formed through patterning, so more than one air passage 36b can be formed with respect to one cover.

[0159] After that, in step (d), using Figure 9A And Figure 9B The method shown, the cover substrate 24b is accurately aligned and laminated on the piezoresistive semiconductor wafer 40. In addition, the steps 35 (etching grooves 35e, 35d) of the cover substrate 24b correspond to Figure 13 The etching grooves 35e, 35d of

[0160] When pressure and temperature are applied during bonding, the piezoresistive semiconductor wafer 40 and the cover substrate 24b are closely adhered with the resin material pattern 45a as the bonding layer. In addition, the bonding conditions are implemented under 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 resin material before bonding is formed with a thickness taking into account the shrinkage amount so that the thickness of the bonding layer after bonding is 50 μm or less, particularly about 20 μm.

[0161] Next, in the (e) process, a back grinding tape 41 is pasted on the lower surface side of the piezoresistive semiconductor wafer 40, and the upper surface side of the cover substrate 24b is ground. In addition, the thickness of the cover is processed to be about 200 μm. In the grinding process, first, rough grinding is performed using a #2000 grinding wheel, and then, a finer grinding wheel of #5000 or more is used for grinding in the middle. Thereby, the cover substrate 24b can be separated into a plurality of covers 24c. Moreover, an air passage 36b can be formed in each of the separated covers 24c simultaneously.

[0162] In addition, in the method for thinning the cover substrate 24b, thinning can be achieved even by using grinding and chemical mechanical polishing (CMP: Chemical Mechanical Polishing). In this method, it is difficult to generate thickness deviations, and the piezoresistive semiconductor elements with a uniform thickness can be ground at the wafer level, so the productivity is excellent. If grinding is performed until the end using a coarse grinding wheel, such as a #2000 grinding wheel, debris and the like are generated at the corners, so the surface of the ground cover 24c needs to be finish-ground using a finer grinding wheel of #5000 or more. At this time, the cavity space 43 formed in the cover 24c is connected to the outside through the air passage 36b.

[0163] Next, in the (f) process, after fixing the lower surface side of the piezoresistive semiconductor wafer 40 with a dicing tape 42, a dicing groove 39a (semi-dicing groove) that has been formed halfway is formed in the piezoresistive semiconductor wafer 40 by dicing. Thereby, dicing grooves 39a are formed longitudinally and transversely in the piezoresistive semiconductor wafer 40.

[0164] Finally, in the (g) process, a back grinding tape 41 is pasted on the upper surface side of the cover 24c, and the lower surface side of the piezoresistive semiconductor wafer 40 is ground. The grinding method is the same as the above method. Thereby, the piezoresistive semiconductor chip 3 with the cover 24c can be separated from the wafer state. After that, by picking up the piezoresistive semiconductor chip 3, the pressure sensor of the piezoresistive semiconductor chip with the cover is completed.

[0165] In addition, the thickness of the piezoresistive semiconductor chip 3 is preferably 80 μm or less, particularly preferably around 50 μm. If the thickness of the silicon becomes thinner, the deformation region can be expanded for minute pressure fluctuations, and the detection accuracy can be improved.

[0166] Moreover, in the case where the piezoresistive semiconductor chip 3 is thinned by thinning processing, electrical leakage may occur due to the structure of the piezoresistive element or the 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.

[0167] The electrode 46 is formed outside the lid body 24c, and the air vent path 36b connected to the external air is also formed in each piezoresistive semiconductor chip 3.

[0168] Moreover, since the air vent path 36b can be formed by patterning the resin material as the bonding layer, it can be freely arranged. The width of the air vent path 36b can also be arbitrarily set, but it is preferably expanded by a few micrometers according to the pressure and temperature during bonding, so a width of 30 μm or less is preferred. There is an effect that the narrower the width, the more effectively foreign matters such as dust can be prevented from entering. Also, the shape of the air vent path 36b can also adopt a structure in which a wire is bent, or a structure formed by a curve.

[0169] In this way, by using a method different from those of the first and second embodiments, that is, by providing an air vent path at the joint, the overall thickness of the pressure sensor can be processed to about 300 μm without adding processes, and a piezoresistive semiconductor chip with a lid film can be manufactured with good productivity. By changing the thickness of the lid body, further thinning can be achieved. In addition, the chip size can be about 2.2 mm square.

[0170] Example 4

[0171] Refer to Figure 15 , and a method for manufacturing the pressure sensor module according to the fourth embodiment of the present invention will be described.

[0172] Figure 15 is a diagram showing the process flow for manufacturing a pressure sensor using wafer-level packaging. Figure 15 Cross-sectional views of each process from step (a) to step (g) are shown.

[0173] In the process of the wafer-level packaging method including the formation of the air vent path of the pressure sensor, even if it is a process different from that of the third embodiment ( Figure 14 ), a piezoresistive semiconductor chip with a lid can be realized.

[0174] Figure 15 Steps (a) to (d) of Figure 14The processes from (a) to (d) are the same, and repeated descriptions are omitted.

[0175] In the (e) process, a back grinding tape 41 is pasted on the upper surface side of the lid substrate 24b, and grinding is performed on the lower surface side of the piezoresistive semiconductor wafer 40. Thereby, the thickness of the piezoresistive semiconductor chip 3 can be made thinner.

[0176] The thickness of the piezoresistive semiconductor chip 3 is preferably 100 μm or less, and particularly preferably about 50 μm. If the thickness of silicon becomes thinner, the deformation region can be expanded for a minute pressure change, and the detection accuracy can be improved.

[0177] In the above grinding process, first, rough grinding is performed using a #2000 grinding wheel, and then, from the middle, grinding is performed using a finer grinding wheel of #5000 or more.

[0178] In addition, in the method for thinning the piezoresistive semiconductor wafer 40, thinning can be achieved even by using grinding and chemical mechanical polishing (CMP: Chemical Mechanical Polishing). In this method, it is difficult to generate a thickness deviation, and grinding can be performed on the piezoresistive semiconductor elements with a uniform thickness at the wafer level, so the productivity is excellent.

[0179] In addition, in the case where the piezoresistive semiconductor chip 3 is thinned by thinning processing, a case of electric leakage due to the structure of the piezoresistive element or the conductivity of the silicon material is assumed, but in the present invention, it can be dealt with by forming a thin film insulator on the surface of the thinned piezoresistive semiconductor chip 3.

[0180] Next, in the (f) process, a back grinding tape 41 is pasted on the lower surface side of the thinned piezoresistive semiconductor wafer 40, and grinding is performed on the upper surface side of the lid substrate 24b. In addition, the grinding method is the same as the above method, and the thickness of the lid 24b is processed to be about 180 μm. Thereby, the lid substrate 24b can be separated into a plurality of lids 24d. Further, an air passage 36b can be formed simultaneously in each of the separated lids 24d. The cavity space 43 formed in the lid 24d is connected to the outside through the air passage 36b.

[0181] Finally, in step (g), after the lower surface side of the piezoresistive semiconductor wafer 40 is fixed with the dicing tape 42, a dicing groove 39b (full dicing groove) is formed in the piezoresistive semiconductor wafer 40 by dicing. The dicing grooves 39b are formed longitudinally and transversely in the piezoresistive semiconductor wafer 40. Thereby, the piezoresistive semiconductor chip 3 with the lid body 24d can be separated from the wafer state. After that, by picking up the piezoresistive semiconductor chip 3, the pressure sensor of the piezoresistive semiconductor chip with the lid body is completed.

[0182] The electrode 46 is formed outside the lid body 24d, and the ventilation path 36b connected to the external air is also formed in each piezoresistive semiconductor chip 3.

[0183] Moreover, since the ventilation path 36b can be formed by patterning the resin material as the bonding layer, it can be freely arranged. The width of the ventilation path 36b can also be arbitrarily set, but it is preferably expanded by about several micrometers according to the pressure and temperature during bonding, so a width of 30 μm or less is preferred. The narrower the width, the more effective it is in preventing the intrusion of foreign matters such as dust. Also, the shape of the ventilation path 36b can also adopt a structure in which a wire is bent or a structure formed by a curve.

[0184] Example 5

[0185] Refer to Figure 17 , and the pressure sensor module of Example 5 of the present invention will be described.

[0186] Figure 17 It is a cross-sectional view showing the structure of the pressure sensor module of this embodiment.

[0187] In Examples 1 to 4, the structure and manufacturing process related to the pressure sensor structure of the present invention were described. However, as a method for improving the bonding strength of the pressure sensor disposed on the flow path substrate 25, a method of forming a thin film 29 made of the same material as the piezoresistive semiconductor chip 3 around the outlet of the branch path 20 of the flow path substrate 25 can be applied.

[0188] For example, in the case where the thin film 29 is not formed, the bonding interface 18 composed of two materials, stainless steel as the material of the flow path substrate 25 and silicon as the material of the piezoresistive semiconductor chip 3, is formed by the bonding layer.

[0189] When forming the thin film 29 on the stainless steel, only the adhesion of the interface of the bonding layer 18 to the same silicon needs to be considered, and it is also easy to select the material of the adhesive applied to the bonding layer 18.

[0190] In addition, when the thickness of the thin film 29 formed around the outlet of the branch path 20 of the flow path substrate 25 is 100 nm to 300 nm, the bonding strength can be improved. It can also be formed thicker than the above thickness, but if it is formed too thick, there is a possibility of peeling off from the stainless steel due to the stress of the thin film itself.

[0191] In the present invention, the position and formation method of the ventilation path can be selected, and two methods can also be selected regarding the manufacturing process. Therefore, the range of the manufacturing method is large and can be freely selected.

[0192] In addition, the present invention is not limited to the above-described embodiments and includes various modified examples. For example, the above-described embodiments have been described in detail for easy understanding of the present invention and are not necessarily limited to having all the structures described. Also, a part of the structure of one embodiment can be replaced with the structure of another embodiment, and the structure of another embodiment can also be added to the structure of one embodiment. And, addition, deletion, and replacement of other structures can be made to a part of the structure of each embodiment.

[0193] Symbol Explanation

[0194] 1 - Dispensing device, 2 - Nozzle, 3 - Piezoresistive semiconductor chip, 4 - Syringe pump, 5 - Solenoid valve, 6 - Gear pump, 7 - Tank, 8 - Pipe, 9 - Container, 10 - Plunger, 11 - Ball screw, 12 - Driving motor, 13 - Sample dispensing mechanism, 14 - Control substrate, 15A, 15B - Pressure sensor modules, 16 - Dispensing arm, 17 - Piezoresistive element, 18 - Adhesive layer, 19 - Flow path, 19a - Flow path inlet, 19b - Flow path outlet, 20, 20a - Branch path, 21 - System water, 22 - Liquid, 23 - Sectioned air, 24 - Cover, 24a, 24b, 24c, 24d - Cover substrate, 25 - Flow path 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 - Etching groove, 35 - Step, 36, 36a, 36b - Ventilation path, 37, 37a, 37b, 37c, 43 - Cavity space, 39a, 39b - Cutting groove, 40 - Piezoresistive semiconductor wafer, 41 - Back grinding tape, 42 - Cutting tape, 44 - Water pressure, 45 - Bonding layer (resin material), 45a - Resin material pattern, 46 - Electrode, 46a, 46b - Electrode pad, 47a, 47b - Alignment mark, 48 - Flexible substrate, 49 - Electric wire, 50 - Stand, 51 - Deformation region.

Claims

1. A pressure sensor module, characterized in that, Comprising: A flow path substrate having a flow path inside and a branch path branched from the above-mentioned flow path; A semiconductor chip having a piezoresistive element and disposed so as to cover the opening of the above-mentioned branch path; And A cover body joined to the above-mentioned semiconductor chip so as to cover the above-mentioned piezoresistive element and forming a cavity between the cover body and the above-mentioned semiconductor chip, An air vent path communicating the above-mentioned cavity with the outside is formed in the above-mentioned cover body or the joint portion between the above-mentioned cover body and the above-mentioned semiconductor chip, In the normal direction, the shape of the opening of the above-mentioned branch path and the shape of the above-mentioned cavity are substantially similar shapes.

2. The pressure sensor module according to claim 1, wherein When looking down at the above-mentioned pressure sensor module, the shape of the opening of the above-mentioned branch path and the shape of the above-mentioned cavity are substantially similar shapes.

3. The pressure sensor module according to claim 1, wherein The shape of the above-mentioned cavity is different in length in the long side direction and the short side direction of the above-mentioned pressure sensor module and has lengths symmetric with respect to the center point of the above-mentioned cavity.

4. The pressure sensor module according to claim 1, wherein The above-mentioned air vent path is formed along the normal direction in the above-mentioned cavity of the above-mentioned cover body.

5. The pressure sensor module according to claim 1, wherein The above-mentioned cover body and the above-mentioned semiconductor chip are joined via a resin material, The above-mentioned air vent path is formed in the above-mentioned resin material.

6. The pressure sensor module according to claim 1, wherein The above-mentioned semiconductor chip is joined to the above-mentioned flow path substrate via an adhesive layer, A film having the same material as the above-mentioned semiconductor chip is formed on the joint surface of the above-mentioned flow path substrate where the above-mentioned semiconductor chip is joined.

7. A manufacturing method of a pressure sensor module for manufacturing the pressure sensor module according to any one of claims 1 to 6, characterized in that, Having the following steps: (a) Prepare a first substrate formed with a plurality of piezoresistive elements; (b) Using a multi-layer mask method, form a plurality of grooves with different depths in a second substrate by dry etching; (c) Form a resin material on the surface of the above-mentioned first substrate and perform patterning; (d) Use the alignment marks of the above-mentioned first substrate and the alignment marks of the above-mentioned second substrate for positioning, heat and press to join the above-mentioned first substrate and the above-mentioned second substrate; and (e) Combine the step of thinning the above-mentioned first substrate and the above-mentioned second substrate by grinding the surfaces on the opposite sides of the joint surfaces of the above-mentioned first substrate and the above-mentioned second substrate that have become integrated through the above-mentioned step (d), and the step of cutting the above-mentioned first substrate, and singulate the above-mentioned first substrate and the above-mentioned second substrate that have become integrated.

8. The method for manufacturing a pressure sensor module according to claim 7, wherein Grind the surfaces on the opposite sides of the joint surfaces of the above-mentioned first substrate and the above-mentioned second substrate that have become integrated with a grinding wheel finer than #5000 to make the thickness of the above-mentioned first substrate and the above-mentioned second substrate that have become integrated 300 μm or less.

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