Fluid sensor module

Abstract

To provide a fluid sensor module which offers high electrical insulation and reliability.SOLUTION: A fluid sensor module of the preset invention has an internal flow channel 19 and an open-ended branch channel 20 branching from the flow channel 19, and comprises a flow channel housing 25 made of a metal material, a semiconductor chip 3 covering an opening 20a of the branch flow channel 20, a multilayer film 29 with an insulation film provided around the opening 20a of the branch channel 20 on a surface of the flow channel housing 25, and an adhesive layer 18 provided between the multilayer film 29 and the semiconductor chip 3.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present invention relates to a fluid sensor module that measures a physical quantity of a fluid. [Background technology]

[0002] Physical quantities of a fluid (e.g., pressure, temperature, and liquid level) can be measured accurately with high sensitivity when a sensor is placed in direct contact with the fluid. For example, a pressure sensor has a semiconductor element such as a piezoresistor element on a diaphragm made of a non-conductive material such as silicon or ceramics, and the diaphragm is deformed by the pressure of the fluid. This pressure sensor measures the deformation of the diaphragm electrically as a change in resistance using a Wheatstone bridge circuit or the like, and measures the pressure of the fluid by converting the measured change in resistance into a pressure value. In addition, if the Wheatstone bridge circuit of the pressure sensor is replaced with a thermistor semiconductor, a temperature sensor can be constructed that can measure the temperature of the fluid with high accuracy.

[0003] An example of a conventional fluid sensor module is described in Patent Document 1. The pressure sensor module described in Patent Document 1 includes a branch path that branches from a flow path toward the outer surface of the flow path substrate inside the flow path substrate, and includes a piezo-resistance type semiconductor element disposed so as to block an end portion of the branch path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-175292 A Summary of the Invention [Problem to be solved by the invention]

[0005] Substrates equipped with semiconductor elements such as piezoresistance elements may be damaged or malfunction if electrical noise enters from the surroundings. For this reason, it is important that the fluid sensor module is not affected by electrical noise in the measurement environment in order to measure the physical quantity of the fluid with high accuracy. However, conventional fluid sensor modules do not necessarily have sufficient countermeasures against electrical noise.

[0006] For example, in the pressure sensor module described in Patent Document 1, a thin-film insulator is formed on the surface of a thin-film piezoresistance semiconductor element to prevent electrical leakage from the piezoresistance semiconductor element. However, if the semiconductor substrate equipped with the piezoresistance semiconductor element is joined to the flow path substrate by a metal material, there is a concern that the piezoresistance semiconductor element may be damaged or malfunction if electrical noise enters from the flow path substrate.

[0007] Therefore, there is a demand for a highly reliable fluid sensor module that has high electrical insulation and is not prone to damage.

[0008] An object of the present invention is to provide a fluid sensor module having high electrical insulation properties and high reliability. [Means for solving the problem]

[0009] The fluid sensor module according to the present invention has an internal flow path and a branch path that branches off from the flow path and opens, and comprises a flow path housing made of a metal material, a semiconductor chip covering the opening of the branch path, a multilayer film provided around the opening of the branch path on the surface of the flow path housing and comprising an insulating film, and an adhesive layer provided between the multilayer film and the semiconductor chip. Effect of the Invention

[0010] According to the present invention, it is possible to provide a fluid sensor module having high electrical insulation properties and high reliability.

[0011] Problems, configurations and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief description of the drawings]

[0012] [Figure 1A] FIG. 1 is a diagram showing a configuration of a fluid sensor module according to a first embodiment of the present invention, and is an exploded perspective view of the fluid sensor module. [Figure 1B] FIG. 1 is a diagram showing a configuration of a fluid sensor module according to a first embodiment of the present invention, and is a cross-sectional view of the fluid sensor module in the YZ plane. [Diagram 2] 3 is a cross-sectional view in the YZ plane showing an example of a configuration of a multilayer film in the fluid sensor module according to the first embodiment. FIG. [Figure 3A] 3 is an enlarged schematic diagram showing the periphery of a terminal end of a branch path in the fluid sensor module, and is a diagram showing the multilayer film shown in FIG. 2. FIG. [Figure 3B] 13 is a schematic diagram showing an enlarged view of the periphery of an end portion of a branch path in the fluid sensor module, and is a diagram showing an example of the configuration of a multilayer film having even higher peel strength. FIG. [Figure 4] FIG. 2 is a perspective view of the fluid sensor module, showing an example of electrical wiring to a semiconductor chip. [Diagram 5] FIG. 1 is a diagram showing a basic configuration of a dispensing device including a fluid sensor module according to a first embodiment. [Figure 6] 13 is a diagram showing the state inside the pipe immediately after the nozzle has sucked in liquid in the arm. FIG. [Figure 7] FIG. 11 is a diagram showing a configuration of a fluid sensor module according to a second embodiment of the present invention, and is a cross-sectional view of the fluid sensor module in the YZ plane. [Figure 8] FIG. 11 is a cross-sectional view of a stainless steel tank equipped with a liquid level sensor and a liquid level switch in a third embodiment of the present invention. [Figure 9] 13 is an enlarged schematic view showing the periphery of a terminal end of a branch path in a fluid sensor module according to a comparative example; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the fluid sensor module according to the present invention, the semiconductor chip that measures the physical quantity of the fluid can ensure insulation reliability and adhesion reliability by the multilayer film containing an insulating material formed on the flow path housing. Therefore, the sensing part of the semiconductor chip (semiconductor element such as a piezoresistor element) is not affected by electrical noise from the flow path housing side. When the fluid sensor module according to the present invention is used as a pressure sensor in a dispensing device and the fluid sensor module is installed near a nozzle, minute pressure changes due to suction and discharge at the nozzle can be grasped, and abnormalities in dispensing can be detected and the dispensed amount can be estimated with high accuracy.

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The examples are illustrative for explaining the present invention, and are omitted and simplified as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0015] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0016] When there are multiple components having the same or similar functions, they may be described by using the same reference numerals with different subscripts, or when there is no need to distinguish between these multiple components, the subscripts may be omitted.

[0017] In the following description, silicon dioxide (SiO2) is also referred to as silicon dioxide. EXAMPLES

[0018] A fluid sensor module according to a first embodiment of the present invention will be described with reference to Fig. 1A to Fig. 6. The fluid sensor module measures physical quantities of a fluid (e.g., water) flowing therein, such as pressure, temperature, and liquid level. In the following description, in the fluid sensor module, the flow direction of the fluid (long side direction of the fluid sensor module) is defined as the Y direction, the height direction is defined as the Z direction, and the direction perpendicular to the Y direction and the Z direction (short side direction of the fluid sensor module) is defined as the X direction.

[0019] 1A and 1B, the configuration of a fluid sensor module 15 according to this embodiment will be described. In the following description, as an example, the fluid sensor module 15 measures the pressure of a fluid flowing inside the fluid sensor module 15.

[0020] 1A and 1B are diagrams showing a configuration of a fluid sensor module 15 according to this embodiment. Fig. 1A is an exploded perspective view of the fluid sensor module 15. Fig. 1B is a cross-sectional view of the fluid sensor module 15 in the YZ plane.

[0021] The fluid sensor module 15 includes a flow path housing 25 and a semiconductor chip 3, and is installed, for example, in a pipe through which a fluid flows. The flow path housing 25 is also called a flow path substrate.

[0022] The flow path housing 25 has a flow path 19 therein. A fluid whose physical quantity is to be measured flows through the flow path 19. The flow path housing 25 has a flow path inlet 19a through which the fluid flows into the flow path 19, and a flow path outlet 19b through which the fluid flows out of the flow path 19. The flow path inlet 19a and the flow path outlet 19b are provided with threaded portions (not shown). The threaded portions enable the fluid sensor module 15 to be connected to an apparatus in which the fluid sensor module 15 is installed (for example, a dispensing apparatus 1 described below with reference to FIG. 5). The flow path 19 is connected, via a joint, to a pipe provided in the apparatus in which the fluid sensor module 15 is installed.

[0023] The flow path housing 25 has therein a branch path 20 that branches off from the flow path 19 and opens toward the outer surface of the flow path housing 25. In this embodiment, as shown in Figs. 1A and 1B, the branch path 20 branches off from the flow path 19 and opens toward the Z direction (upward in the height direction). That is, the branch path 20 has an opening 20a at the top of the flow path housing 25, and this opening 20a is the terminal end. The direction in which the branch path 20 branches off is not limited to this direction, and may be downward in the height direction or in the X direction (horizontal direction).

[0024] The flow path housing 25 is made of a metal material, and is preferably made of stainless steel (SUS304) having excellent corrosion resistance.

[0025] The semiconductor chip 3 is formed of a thin film and is arranged so as to cover the opening 20a of the branch path 20. The semiconductor chip 3 has a semiconductor element 17, for example a piezoresistance element, in its central portion. The semiconductor element 17 is, for example, an element for detecting the distortion of a diaphragm. The semiconductor chip 3 has a plurality of electrode pads 27 in its peripheral portion for transmitting an electrical signal to the outside. As an example, FIGS. 1A and 1B show an example in which the plurality of electrode pads 27 are concentrated and arranged at one end of the semiconductor chip 3. The plurality of electrode pads 27 may be arranged at four ends of the semiconductor chip 3. In this embodiment, the length of one side of the semiconductor chip 3 is 2.7 mm.

[0026] A multilayer film 29 is provided on the surface of the flow path housing 25 around the opening 20a of the branch path 20. An adhesive layer 18 is provided on the multilayer film 29. The semiconductor chip 3 is bonded (adhered) to the multilayer film 29 via the adhesive layer 18, and is bonded to the flow path housing 25 via the adhesive layer 18 and the multilayer film 29. That is, in the fluid sensor module 15 according to this embodiment, the multilayer film 29 is provided on the flow path housing 25, the adhesive layer 18 is provided on the multilayer film 29, and the semiconductor chip 3 is provided on the adhesive layer 18.

[0027] The adhesive layer 18 is provided between the multilayer film 29 and the semiconductor chip 3, and is preferably made of silver. For example, the adhesive layer 18 can be made of a material such as silver paste containing silver particles. The adhesive layer 18 made of silver paste has the characteristics of having high adhesive strength, being difficult to peel off, and being resistant to water. Therefore, the adhesive layer 18 made of silver paste can improve the reliability of the fluid sensor module 15.

[0028] The multilayer film 29 includes an insulating film made of an insulating material, and is located between the flow path housing 25 and the adhesive layer 18. The multilayer film 29 will be described in detail later.

[0029] The fluid sensor module 15 according to this embodiment includes the multilayer film 29 having an insulating film on the surface of the flow path housing 25, and thus can improve both electrical insulation and adhesiveness (structural reliability).

[0030] When the stainless steel flow path housing 25 and the semiconductor chip 3 are directly bonded to each other with a metallic silver paste (adhesive layer 18), the flow path housing 25 and the semiconductor chip 3 are electrically conductive to each other. In this configuration, if electrical noise enters the flow path housing 25, the semiconductor chip 3 may be destroyed or malfunction due to the electrical noise.

[0031] In the fluid sensor module 15 according to this embodiment, the semiconductor chip 3 is bonded to the flow path housing 25 via a multilayer film 29 having an adhesive layer 18 and an insulating film, so that electrical noise entering from the flow path housing 25 can be blocked by the insulating film of the multilayer film 29.

[0032] Generally, the insulating structure of a fluid sensor module is considered to be such that a layer of silicon dioxide film is provided as an insulating film on the stainless steel (SUS304) flow path housing 25, and a semiconductor chip is placed on this silicon dioxide film with silver paste interposed as an adhesive layer. However, there is a problem with the adhesiveness at the interface between the silicon dioxide film and the silver paste.

[0033] To address this issue, we performed molecular dynamics simulations to determine the peel energy E at the interface between several types of two layers. The peel energy E between two layers can be expressed by the following formula (1). E = Es - Ec (1) In formula (1), Ec represents the energy of the two layers in a joined state, and Es represents the energy of the two layers in a separated state.

[0034] The peeling energy E between stainless steel (SUS304) and silicon dioxide (SiO2) is 0.318 J / m 2 On the other hand, the peeling energy E between silicon dioxide and silver is 0.100 J / m 2 From these results, it can be considered that the interface between silicon dioxide and silver, to which fluid pressure is repeatedly applied, has a smaller peel energy E than the interface between stainless steel and silicon dioxide, and therefore poses an issue with long-term reliability.

[0035] The peeling energy E between stainless steel (SUS304) and silicon (Si) is 0.337 J / m 2 This is almost the same value as the peeling energy E between stainless steel and silicon dioxide.

[0036] Based on the above analysis results, the fluid sensor module 15 according to this embodiment has a configuration in which the silicon dioxide film and the silver paste do not come into contact with each other. In the fluid sensor module 15 according to this embodiment, the multilayer film 29 contains a material that has good adhesion to both the silver paste and the silicon dioxide, such as silicon.

[0037] FIG. 2 is a cross-sectional view in the YZ plane showing an example of the configuration of the multilayer film 29 in the fluid sensor module 15 according to this embodiment.

[0038] The multilayer film 29 includes a silicon dioxide film 31, which is an insulating film in contact with the flow path housing 25, and a silicon film 30 laminated on the silicon dioxide film 31. The silicon film 30 is in contact with the silver paste, which is the adhesive layer 18. The silicon dioxide and silicon form a siloxane bond via oxygen. Therefore, the silicon dioxide film 31 and the silicon film 30 have high adhesion and do not peel off.

[0039] The fluid sensor module 15 according to this embodiment has high electrical insulation because it includes the silicon dioxide film 31, which is an insulating film. And because the fluid sensor module 15 according to this embodiment includes the silicon film 30 between the silicon dioxide film 31 and the silver paste (adhesive layer 18), the peel strength at the respective interfaces is high, and the structure is highly reliable. For example, the fluid sensor module 15 according to this embodiment does not peel off at the respective films or layers even when pressure fluctuations (tensile stress) of the fluid are repeatedly applied.

[0040] 3A and 3B are schematic diagrams showing an enlarged view of the periphery of the terminal end (opening 20a) of the branch path 20 in the fluid sensor module 15 according to this embodiment. An example of the configuration of the multilayer film 29 will be further described with reference to FIGS. 3A and 3B.

[0041] Fig. 3A shows the multilayer film 29 shown in Fig. 2. That is, the multilayer film 29 includes a silicon dioxide film 31 and a silicon film 30.

[0042] 3A, a silicon dioxide film 31 is provided on a flow path housing 25, a silicon film 30 is provided on the silicon dioxide film 31, a silver paste serving as an adhesive layer 18 is provided on the silicon film 30, and a semiconductor chip 3 is provided on the adhesive layer 18. That is, the semiconductor chip 3 is provided on the flow path housing 25 by the silver paste (adhesive layer 18) via a multilayer film 29.

[0043] The multilayer film 29 is in contact with the branch path 20 through which the fluid flows. The fluid sensor module 15 according to this embodiment is resistant to pressure fluctuations of the fluid and to the penetration of the fluid (water), and therefore has a high reliability of the structure.

[0044] FIG. 9 is an enlarged schematic view showing the periphery of the terminal end of the branch path 20 in a fluid sensor module 55 according to a comparative example.

[0045] In the fluid sensor module 55 according to the comparative example, a silicon film 30 is provided on a flow path housing 25, a silicon dioxide film 31 is provided on the silicon film 30, an adhesive layer 18 made of silver paste is provided on the silicon dioxide film 31, and a semiconductor chip 3 is provided on the adhesive layer 18.

[0046] In the fluid sensor module 55 according to the comparative example, the silicon dioxide film 31 and the adhesive layer 18 (silver paste) are in contact at the interface. As described above, the interface between silicon dioxide and silver has a small peel energy E. Therefore, in the fluid sensor module 55 according to the comparative example, the silicon dioxide film 31 and the adhesive layer 18 are easily peeled off from each other.

[0047] The air pressure peeling test was performed three times on the fluid sensor module 55 according to the comparative example. In these three tests, the average air pressure at which the fluid sensor module 55 was broken was 0.38 MPa. The fluid sensor module 55 was broken due to peeling at the interface between the silicon dioxide film 31 and the adhesive layer 18 (silver paste).

[0048] Similarly, the air pressure peeling test was performed three times on the fluid sensor module 15 according to this embodiment having the multilayer film 29 shown in Fig. 3A. The fluid sensor module 15 according to this embodiment was not destroyed even when the air pressure was increased to 0.9 MPa. Furthermore, the fluid sensor module 15 according to this embodiment was not destroyed even when a test was performed in which an air pressure of 0.6 MPa was repeatedly applied for 100,000 cycles. As can be seen from these test results, the fluid sensor module 15 according to this embodiment has a highly reliable structure and can also achieve good long-term reliability.

[0049] Silicon dioxide has high adhesion to stainless steel (SUS304). In the fluid sensor module 15 according to this embodiment having the multilayer film 29 shown in Fig. 3A, the silicon dioxide film 31 can be provided thickly as an insulating film on the stainless steel flow path housing 25, so that the electrical insulation can be further improved.

[0050] Moreover, from the above test result that the fluid sensor module 15 was not destroyed, it is understood that the peel strength between the silicon film 30 and the adhesive layer 18 (silver paste) is also high.

[0051] The fluid sensor module 15 according to this embodiment includes a multilayer film 29 having a silicon dioxide film 31, which is an insulating film, and a silicon film 30. At the interface in contact with silver (i.e., the adhesive layer 18), the silicon film 30 is disposed, and no silicon dioxide is disposed.

[0052] 3B is a diagram showing an example of the configuration of the multilayer film 29 having even higher peel strength. The multilayer film 29 includes a first silicon film 30a provided in contact with the flow path housing 25, a silicon dioxide film 31 serving as an insulating film provided on the first silicon film 30a, and a second silicon film 30b provided on the silicon dioxide film 31. A silver paste serving as an adhesive layer 18 is provided on the second silicon film 30b, and a semiconductor chip 3 is provided on the adhesive layer 18.

[0053] In the configuration shown in Fig. 3B, the interfaces between the two layers are stainless steel and silicon, silicon and silicon dioxide, and silicon and silver, and the peel strength is higher than that of the configuration shown in Fig. 3A. Therefore, the fluid sensor module 15 according to this embodiment including the multilayer film 29 shown in Fig. 3B has high electrical insulation and high structural reliability.

[0054] In addition, in a configuration in which a stainless steel flow path housing 25 is provided with a silicon dioxide film 31, which is an insulating film, moisture easily penetrates the silicon dioxide interface, so there is a concern that the bonding strength at the interface between the stainless steel and the silicon dioxide will decrease.

[0055] The fluid sensor module 15 according to this embodiment, which includes the multilayer film 29 shown in Fig. 3B, can prevent such a decrease in bonding strength at the interface. In this fluid sensor module 15, the first silicon film 30a is provided on the stainless steel flow path housing 25, and the silicon dioxide film 31 is in contact with the silicon films 30a and 30b, which have high adhesion, so that the bonding strength at the interface can be kept high.

[0056] The multilayer film 29 can be formed by using a thin film forming device such as a sputtering device or an ion plating device. By using such a thin film forming device and masking the portions of the flow path housing 25 where the multilayer film 29 is not to be formed, the multilayer film 29 can be formed at any position of the flow path housing 25. In addition, since thin films can be formed simultaneously on a plurality of flow path housings 25, the multilayer film 29 can be formed in a short time and at low cost.

[0057] After machining, the surface of the flow path housing 25 has minute uneven processing marks. For example, when the arithmetic mean roughness Ra of the surface of the flow path housing 25 is 1.6, the maximum height roughness is about 6 μm to 7 μm. To form a uniform insulating film on the uneven surface of the flow path housing 25, it is necessary to change the thickness of the insulating film according to the surface roughness of the flow path housing 25. For this reason, in forming the multilayer film 29, it is preferable to change the film thickness of the silicon dioxide film 31, which is the insulating film, according to the surface roughness of the flow path housing 25.

[0058] In general, reducing the processing roughness of the surface of the flow path housing 25, for example, mirror finishing the surface of the flow path housing 25, increases the processing cost. For this reason, it is preferable that the general processing accuracy is an arithmetic mean roughness Ra of about 1.6.

[0059] According to experimental results, in order to form the silicon dioxide film 31 on the flow path housing 25 having this surface roughness, the silicon dioxide film 31 needs to have a thickness of 1.2 μm or more. The dielectric strength voltage of the silicon dioxide film 31 at this time is about 44 V, which is sufficient compared to the driving voltage of 5 V that drives the semiconductor element 17. If the thickness of the silicon dioxide film 31 is thinner than 1.2 μm, it is difficult for the silicon dioxide film 31 to be conductive and to obtain an electrically insulated state, and it is also difficult to prevent electrical noise.

[0060] Therefore, when the arithmetic mean roughness Ra of the surface of the flow path housing 25 is 1.6, it is preferable that the thickness of the silicon dioxide film 31 is 1.2 μm or more.

[0061] On the other hand, since the silicon film 30 is a material involved in adhesion or bonding, it is sufficient that it has a thickness of about 0.2 μm.

[0062] FIG. 4 is a perspective view of the fluid sensor module 15, showing an example of electrical wiring to the semiconductor chip 3. As shown in FIG.

[0063] The semiconductor chip 3 is connected to a flexible substrate 26 for electrical wiring by wires 28. The flexible substrate 26 has electrode pads 26a and is supported by a stand (not shown). The electrode pads 27 of the semiconductor chip 3 are connected to the electrode pads 26a of the flexible substrate 26 by wires 28.

[0064] For example, gold wires and aluminum wires can be used for the wires 28. Anisotropic conductive films (ACF) may be used instead of the wires 28. Note that a printed circuit board (PCB) may be used for the flexible substrate 26 for electrical wiring.

[0065] The fluid that has flowed through the flow path 19 flows into the branch path 20, and applies pressure to the semiconductor chip 3. When pressure is applied, the semiconductor chip 3 deforms, and transmits this deformation as an electrical signal to the flexible substrate 26. The pressure of the fluid is measured from the electrical signal transmitted to the flexible substrate 26.

[0066] In the fluid sensor module 15 according to this embodiment, the thin-film semiconductor chip 3 is disposed so as to cover the opening 20a of the branch path 20. In the fluid sensor module 15 according to this embodiment, the distance from the flow path 19 to the opening 20a (terminal end) of the branch path 20 is short, so that the change in pressure of the fluid flowing through the flow path 19 can be detected accurately and quickly.

[0067] The semiconductor chip 3 may include a strain gauge, a piezoelectric element, or the like, in addition to a piezoresistance element, as the semiconductor element 17 for detecting the distortion of the diaphragm.

[0068] 5 is a diagram showing a basic configuration of a dispensing device 1 including a fluid sensor module 15 according to this embodiment. The dispensing device 1 is a device that automatically dispenses liquid such as a sample or a reagent.

[0069] The dispensing device 1 includes, as a flow path system, a nozzle 2, a syringe pump 4, a solenoid valve 5, a gear pump 6, and a system water tank 7. These components are connected to each other via piping 8. The dispensing device 1 also includes a dispensing mechanism 13 which is a mechanism for dispensing liquid, an arm 16 which is a mechanism for moving the nozzle 2, and a control board 14 which serves as a control unit for controlling the entire device.

[0070] The syringe pump 4 includes 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 dispensing mechanism 13 and the like.

[0071] The arm 16 includes therein a fluid sensor module 15. The arm 16 is capable of rotating and moving up and down in order to move the nozzle 2 to a position where the liquid is sucked and discharged.

[0072] FIG. 6 is a diagram showing the state inside pipe 8 immediately after nozzle 2 has sucked in liquid in arm 16. As shown in FIG.

[0073] The inside of the pipe 8 is filled with system water 21, which is water for transmitting syringe pressure. The pipe 8 transmits the pressure of the system water 21 by the syringe pump 4 (FIG. 5) to the nozzle 2. By transmitting this pressure, the nozzle 2 can suck in and discharge liquid 22, which is a sample or a reagent.

[0074] When the nozzle 2 aspirates the liquid 22, it pulls the plunger 10 (FIG. 5) inside the syringe pump 4 with the solenoid valve 5 (FIG. 5) closed. When the nozzle 2 discharges the liquid 22, it pushes the plunger 10 inside the syringe pump 4 into the container 9 (FIG. 5) with the solenoid valve 5 closed. When the nozzle 2 aspirates the liquid 22, it first aspirates the dividing air 23 for dividing the liquid 22 so that the liquid 22 does not mix with the system water 21 inside the piping 8, and then aspirates the liquid 22.

[0075] After the nozzle 2 ejects the liquid 22, the nozzle 2 is washed. When washing the nozzle 2, washing water is applied to the outer wall of the nozzle 2, and at the same time, the system water 21 present in the flow path inside the nozzle 2 is pushed out. To push out the system water 21 from inside the nozzle 2, the solenoid valve 5 (FIG. 5) is opened and the pressure of the gear pump 6 (FIG. 5) is used. In this way, the system water 21 can be pushed out at a higher pressure than when it is pushed out by the syringe pump 4.

[0076] In the dispensing device 1, a fluid sensor module 15 is connected to the piping 8 in order to detect abnormalities such as clogging of the nozzle 2 or dry suction that may occur during dispensing operation. The fluid sensor module 15 monitors the pressure of the system water 21 and detects pressure changes of the system water 21 that occur when abnormalities such as clogging of the nozzle 2 or dry suction occur.

[0077] The fluid sensor module 15 according to this embodiment includes a small, thin-film semiconductor chip 3 at the opening 20a of the branch channel 20 formed in the channel housing 25, and therefore can be used as a small sensor.

[0078] The fluid sensor module 15 according to this embodiment can be used as a small pressure sensor, and can be installed at any position where pressure is to be measured. In the example shown in Fig. 5, the dispensing device 1 is provided with the fluid sensor module 15 inside the arm 16, which is located as close to the nozzle 2 as possible, in order to sensitively detect pressure changes in the nozzle 2. The fluid sensor module 15 is not limited to being installed inside the arm 16, and can be installed at any position, such as on the side of the dispensing mechanism 13.

[0079] In this embodiment, as an example, the fluid sensor module 15 measures the pressure of the fluid, and the semiconductor chip 3 includes a piezoresistance element as the semiconductor element 17. The fluid sensor module 15 can measure the temperature of the fluid because the semiconductor chip 3 includes a thermistor element as the semiconductor element 17. Such a fluid sensor module 15 can be used as a small temperature sensor, and can be attached to any position of the object whose temperature is to be measured.

[0080] The fluid sensor module 15, which is a temperature sensor, can have improved electrical insulation and adhesion, similar to the fluid sensor module 15, which is a pressure sensor, and even if it is installed in a position where pressure is applied, electrical noise can be prevented and reliability can be improved. EXAMPLES

[0081] A fluid sensor module 15 according to a second embodiment of the present invention will be described with reference to Fig. 7. The following mainly describes the differences between the fluid sensor module 15 according to the present embodiment and the fluid sensor module 15 according to the first embodiment. The fluid sensor module 15 according to the present embodiment also measures the pressure as a physical quantity of the fluid flowing therein.

[0082] FIG. 7 is a diagram showing the configuration of a fluid sensor module 15 according to this embodiment, and is a cross-sectional view of the fluid sensor module 15 in the YZ plane.

[0083] The multilayer film 29 includes a silicon dioxide film 31 that is an insulating film and is in contact with the flow path housing 25 , and a silicon film 30 that is laminated on the silicon dioxide film 31 .

[0084] The fluid sensor module 15 according to this embodiment includes a cap 24 that covers a part of the semiconductor chip 3. The cap 24 is provided on the upper part of the semiconductor chip 3, and is a member that covers the semiconductor element 17 included in the semiconductor chip 3, and can be made of silicon or glass.

[0085] The cap 24 has a cavity space 33 between itself and the semiconductor chip 3, more specifically, between itself and the semiconductor element 17. The cavity space 33 is a space for preventing the semiconductor chip 3 from coming into contact with the cap 24 when the semiconductor chip 3 is slightly deformed by the pressure of the fluid.

[0086] The cap 24 is bonded to the semiconductor chip 3 by a plurality of bonding portions 32. The bonding portions 32 can be made of an insulating material. If the material of the bonding portions 32 is a photosensitive resin material that can be patterned, the bonding portions 32 can be arranged in any pattern.

[0087] The fluid sensor module 15 according to this embodiment includes a pressing mechanism 34 on the upper part of the cap 24. The pressing mechanism 34 is a member for pressing the cap 24 against the semiconductor chip 3. For example, the pressing mechanism 34 includes a coil spring, and presses the cap 24 against the semiconductor chip 3 by the elastic force of the coil spring.

[0088] The pressure of the fluid flowing through the branch path 20 applies a tensile stress to the semiconductor chip 3. The pressing mechanism 34 applies a force to the semiconductor chip 3 in a direction opposite to the direction in which the pressure of the fluid is applied, and can apply a compressive stress to the adhesive portion (e.g., adhesive layer 18) of the semiconductor chip 3 to the flow path housing 25.

[0089] The fluid sensor module 15 of this embodiment is equipped with the cap 24 and the pressing mechanism 34, thereby providing high adhesion reliability against the fluid pressure repeatedly applied to the underside of the semiconductor chip 3, preventing fluid leakage at the adhesive joint of the semiconductor chip 3, and improving reliability.

[0090] Moreover, in the fluid sensor module 15 according to this embodiment, the semiconductor chip 3 is insulated from the cap 24 and the pressing mechanism 34 by a joint 32 made of an insulating material. That is, in the fluid sensor module 15 according to this embodiment, insulating materials are disposed both above and below (both sides in the Z direction) the semiconductor chip 3. Therefore, the fluid sensor module 15 according to this embodiment has high electrical insulation and can prevent electrical noise from the upper and lower surfaces of the semiconductor chip 3, and can more effectively prevent electrical noise from entering from the outside. EXAMPLES

[0091] A fluid sensor module according to a third embodiment of the present invention will be described with reference to Fig. 8. The following mainly describes the differences between the fluid sensor module 15 according to the third embodiment and the fluid sensor module 15 according to the first embodiment. The fluid sensor module 15 according to the third embodiment measures the liquid level as a physical quantity of the fluid.

[0092] Fig. 8 is a cross-sectional view of a stainless steel tank 37 equipped with a liquid level sensor 35 and a liquid level switch 36. In Fig. 8, the long side direction of the stainless steel tank 37 is the Y direction, the height direction is the Z direction, and the direction perpendicular to the Y direction and Z direction is the X direction.

[0093] The stainless steel tank 37 contains a fluid, liquid 42. The stainless steel tank 37 is equipped with a pipe 8a for introducing the liquid 42 and a pipe 8b for discharging the liquid 42. The pipes 8a and 8b are each connected to the stainless steel tank 37 via a valve 38.

[0094] The stainless steel tank 37 is provided with a top lid 40 and a liquid level sensor 35 at its top. The liquid level sensor 35 is a sensor that detects the level of the liquid 42 to measure the amount of the liquid 42 contained in the stainless steel tank 37, and has a known configuration. The liquid level sensor 35 is attached to the top lid 40 by a screw portion (not shown) formed in the top lid 40, with a sealing material 39 in between. An electrical cord 41 for transmitting an electrical signal is connected to the liquid level sensor 35.

[0095] The stainless steel tank 37 is provided with the fluid sensor module 15 according to this embodiment on its side surface. The stainless steel tank 37 shown in Fig. 8 is provided with two fluid sensor modules 15 positioned separately in the vertical direction (Z direction).

[0096] Of the two fluid sensor modules 15, the upper fluid sensor module 15 detects when the level of the liquid 42 reaches the upper limit of the stainless steel tank 37 and issues a warning signal. The lower fluid sensor module 15 detects when the level of the liquid 42 reaches the lower limit of the stainless steel tank 37 and issues a warning signal.

[0097] The fluid sensor module 15 according to the present embodiment includes a side wall of a stainless steel tank 37, a multilayer film 29 provided on the side wall of the stainless steel tank 37, an adhesive layer 18 provided on the multilayer film 29, and a liquid level switch 36 provided on the adhesive layer 18. The side wall of the stainless steel tank 37 corresponds to the flow path housing 25 of the fluid sensor module 15 according to the first or second embodiment.

[0098] The multilayer film 29 includes a silicon dioxide film 31 in contact with the side wall of the stainless steel tank 37, and a silicon film 30 provided on the silicon dioxide film 31. The silicon film 30 is in contact with the adhesive layer 18. The adhesive layer 18 is made of silver paste.

[0099] The liquid level switch 36 is a sensor that detects the position of the liquid level of the liquid 42 inside the stainless steel tank 37, and has a known configuration. The liquid level switch 36 corresponds to the semiconductor chip 3 of the fluid sensor module 15 according to the first or second embodiment.

[0100] The fluid sensor module 15 according to this embodiment has the above-mentioned configuration, and since the liquid level switch 36 is insulated from the stainless steel tank 37, it is possible to prevent electrical noise from entering the liquid level switch 36 from the stainless steel tank 37. Like the fluid sensor module 15 according to the first embodiment, the fluid sensor module 15 according to this embodiment can improve both the electrical insulation property and the adhesive property (structural reliability).

[0101] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the configurations described. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete a part of the configuration of each embodiment, or to add or replace another configuration. [Explanation of symbols]

[0102] 1...dispensing device, 2...nozzle, 3...semiconductor chip, 4...syringe pump, 5...solenoid valve, 6...gear pump, 7...system water tank, 8...piping, 8a, 8b...piping, 9...container, 10...plunger, 11...ball screw, 12...driving motor, 13...dispensing mechanism, 14...control board, 15...fluid sensor module, 16...arm, 17...semiconductor element, 18...adhesive layer, 19...flow path, 19a...flow path inlet, 19b...flow path outlet, 20...branch path, 20a...branch path opening, 21...system water, 22...liquid, 23...branched air, 24... Cap, 25...flow path housing, 26...flexible substrate, 26a...electrode pad, 27...electrode pad, 28...wire, 29...multilayer film, 30...silicon film, 30a...first silicon film, 30b...second silicon film, 31...silicon dioxide film, 32...joint, 33...cavity space, 34...pressure mechanism, 35...liquid level sensor, 36...liquid level switch, 37...stainless steel tank, 38...valve, 39...sealing material, 40...top cover, 41...electrical cord, 42...liquid, 55...fluid sensor module according to comparative example.

Claims

1. A flow path housing made of a metal material and including a flow path therein and a branch path branching off from the flow path and opening therein; a semiconductor chip covering an opening of the branch path; a multilayer film provided around the opening of the branch path on a surface of the flow path housing and including an insulating film; an adhesive layer provided between the multilayer film and the semiconductor chip; A fluid sensor module comprising:

2. The adhesive layer is made of silver paste, The multilayer film includes a silicon dioxide film as the insulating film and a silicon film provided on the insulating film. The fluid sensor module according to claim 1 .

3. The silicon film of the multilayer film is in contact with the adhesive layer. The fluid sensor module according to claim 2 .

4. The arithmetic mean roughness Ra of the surface of the flow path housing is 1.6, and the thickness of the silicon dioxide film is 1.2 μm or more. The fluid sensor module according to claim 2 .

5. a cap provided on an upper portion of the semiconductor chip to cover a portion of the semiconductor chip and joined to the semiconductor chip by an insulating material; a pressing mechanism for pressing the cap against the semiconductor chip; Equipped with The fluid sensor module according to claim 1 .

Images