Surface mountable thin piezoelectric blower device

Abstract

To meet a demand of a piezoelectric blower device which can be applied to a lot of applications which need the piezoelectric blower device to be incorporated in a small and thin device, as typified by a portable terminal, to handle high pressure air at a large flow rate.SOLUTION: In a thin piezoelectric blower device, a one-way valve function is provided at a center in a diaphragm which is displaced in a swinging manner so that swinging of the one-way valve follows a drive frequency when the piezoelectric blower device is downsized and its drive frequency becomes high, and a flow of fluid is adjusted from a hole made at a piezoelectric element center part. Further, metal materials having high strength are joined in a laminated manner to form a cavity and a blower housing. Furthermore, forms of electric connection and passage connection which are designed assuming that the piezoelectric blower device is mounted on a portable terminal in advance are created.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a structure of a thin piezoelectric blower device suitable for being built into small electronic devices such as mobile terminals. [Background technology]

[0002] Piezoelectric blower devices use a piezoelectric element as an actuator to operate a diaphragm at a driving frequency in the high frequency range to blow out gas, and many patent applications have been filed for configurations that have been devised with the assumption of compactness in mind, including the following configuration examples (Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5).

[0003] Patent Document 1 discloses an example of a fluid pump without a check valve, which includes a pump body, a displacer displaced by a driving means, and a pump chamber formed between the displacer and the pump body, the pump chamber being fluidly connected to an inlet and an outlet via a first opening and a second opening not having a check valve, the displacer being composed of a plate-like or diaphragm-like member fixed to the pump body, the pump body being provided with a recess constituting the pump chamber, and an elastic buffer being provided in contact with the pump chamber, the operating force of the driving means acting on a portion of the displacer facing the first opening, the displacer closing the first opening at its first end position and opening the first opening at its second end position, the driving means operating the displacer to cause deformation of the buffer based on the movement of the displacer, and the deformation of the buffer causing a fluid to flow in or out via the second opening.

[0004] However, in the configuration shown in Patent Document 1, unless the relationship of pump volume >> buffer internal volume, which changes with the operation of the displacer, is satisfied, a large pressure difference does not occur, so when handling compressible fluids such as gas, the buffer volume must be limited to a very small value to cause deformation of the buffer. Therefore, the amount of fluid discharged is small, and since the fluid is discharged by the restoring force of the buffer, there is a problem that the back pressure on the outlet side is also small.

[0005] Patent Document 2 discloses an example of a fluid pump comprising an actuator for displacing a movable wall such as a piston or a diaphragm, a drive means for driving and controlling the actuator, a pump chamber whose volume can be changed by the displacement of the movable wall, an inlet flow path for introducing a working fluid into the pump chamber, and an outlet flow path for introducing the working fluid from the pump chamber, the outlet flow path being connected to the pump chamber during pump operation, a composite inertance value of the inlet flow path being smaller than a composite inertance value of the outlet flow path, the inlet flow path being provided with a fluid resistance element whose fluid resistance when the working fluid flows into the pump chamber is smaller than the fluid resistance when the working fluid flows out of the pump chamber, the drive means being provided with a period control means for changing the motion period of the movable wall, and the period control means being provided with the actuator so that a pump chamber volume compression process of the movable wall starts when the pressure in the pump chamber reaches absolute zero atmospheres.

[0006] However, in the configuration shown in Patent Document 2, a piezoelectric element that expands and contracts in the vertical direction is assumed as the actuator that operates the piston or diaphragm. Since the vertical expansion and contraction of piezoelectric elements is generally very small, it is necessary to use a stacked piezoelectric element to obtain a large displacement, which creates the problem that the height of the pump becomes large and it is difficult to implement in a thin mobile terminal.

[0007] Patent Document 3 discloses an example of a piezoelectric micro-blower comprising: a first wall of a blower body which defines a blower chamber between itself and a diaphragm; a first opening which is formed in a portion of the first wall which faces the center of the diaphragm and connects the inside and outside of the blower chamber; a second wall which is provided on the opposite side of the blower chamber with the first wall therebetween and spaced from the first wall; a second opening which is formed in a portion of the second wall which faces the first opening; and an inflow passage which is formed between the first and second wall portions and has an outer end which communicates with the outside and an inner end which is connected to the first and second openings. A central space having an opening area larger than those of the first and second openings is formed at the inner end of the inflow passage which is connected to the first and second openings. As the diaphragm is displaced, the portion of the first wall which faces the central space vibrates.

[0008] However, although the configuration shown in Patent Document 3 can deliver compressible fluid by inertial force, there is no check valve, so the flow rate fluctuates greatly with respect to external pressure, and there is a problem that the product functions are extremely limited in applications in which this device is installed. It is desirable to have a configuration that can deliver compressible fluid at a large flow rate and high pressure even if it is miniaturized as a piezoelectric blower device.

[0009] Patent Document 4 discloses a pumping device including a first vibration plate, a second vibration plate facing the first vibration plate, a peripheral wall portion connecting a peripheral portion of the first vibration plate and a peripheral portion of the second vibration plate, a pump chamber located between the first vibration plate and the second vibration plate and defined by the first vibration plate, the second vibration plate and the peripheral wall portion, and a driver that generates a pressure fluctuation in the pump chamber by bending and vibrating the first vibration plate and the second vibration plate, wherein the first vibration plate is provided with a first hole portion that is arranged at a position overlapping with an axis when viewed along an extension direction of an axis perpendicular to a center portion of the first vibration plate and a center portion of the second vibration plate and is not provided with a check valve, and at least one of the first vibration plate and the second vibration plate is provided with a second hole portion that is arranged at a position not overlapping with the first hole portion when viewed along the extension direction of the axis and is provided with a check valve, In the illustrated example of the fluid pump, at least one of the vibration plates is further provided with a third hole portion, which is arranged in an outer region than the region in which the second hole portion is provided when viewed along the extending direction of the axis line with the axis line as the center, and which does not have a check valve attached thereto.

[0010] The example shown in Patent Document 4 is proposed as a structure that can increase the flow rate compared to conventional examples, but even with this example, the principle structure for obtaining high discharge pressure is not described, and there was a problem that it could not be installed in a thin mobile terminal intended for applications that require the delivery of a large flow rate and high pressure of an incompressible fluid.

[0011] Patent Document 5 discloses a pump body having a substantially cylindrical shape defining a cavity for containing a fluid, the cavity being formed by a side wall closed at both ends by substantially circular end walls, at least one of the end walls being a driven end wall having a central portion and a peripheral portion extending radially outward from the central portion of the driven end wall; an actuator operatively associated with the central portion of the driven end wall to cause an oscillatory movement of the driven end wall, thereby generating a displacement vibration of the driven end wall in a direction substantially perpendicular to the end wall in use, with an annular node between a center of the driven end wall and the side wall; an isolator operatively associated with the peripheral portion of the driven end wall to reduce damping of the displacement vibration; a first opening disposed at a position in the cavity other than the position of the annular node and extending through the pump body; and a first opening in the pump body. An example is shown of a pump having a second opening disposed at a location other than the location of the first opening and extending through the pump body, and a valve disposed in at least one of the first opening and the second opening, wherein, in use, the displacement vibrations generate corresponding radial pressure vibrations of the fluid within the cavity of the pump body causing a flow of fluid through the first and second openings.

[0012] In the example shown in Patent Document 5, an acoustic standing wave is formed in the radial direction of a cylindrical cavity by an actuator that vibrates in the vertical direction, which generates a large amplitude pressure vibration near the center of the cylindrical cavity. Compared with Patent Documents 3 and 4, this is a superior proposal as a principle configuration for sending out compressible fluid at high pressure. However, there are the following problems when trying to manufacture a smaller blower based on this configuration. The first problem is that when the cavity diameter is designed to be small to manufacture a smaller blower, the resonance frequency increases due to the smaller cavity diameter, and the oscillation of the valve (one-way valve) configured based on the principle of being driven by the differential pressure cannot keep up with the resonance frequency, and it may not be possible to function as a one-way valve. Even if it is made small, it is not fully satisfactory for applications that require both a large flow rate and high pressure. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Patent No. 3035854 [Patent Document 2] Patent No. 5003700 [Patent Document 3] Patent No. 4873014 [Patent Document 4] Patent No. 6769568 [Patent Document 5] Special publication 2012-528980 Summary of the Invention [Problem to be solved by the invention]

[0014] The above-mentioned fluid pump or blower uses a piezoelectric element as an actuator, is driven in the high frequency range, and realizes the function of discharging a fluid with a simple configuration, and is certainly a technical proposal that can be adapted to small electronic devices. However, these proposals do not satisfy the requirements for application to applications that require a large flow rate and high pressure when built into a thinner small electronic device, such as a mobile terminal. For example, when a function for measuring blood pressure by pressurizing a cuff is to be built into a mobile terminal or a watch-type mobile device, or when a function for sucking and detecting or counting pollen or air pollutants is to be built into a mobile terminal or a watch-type mobile device, or when it is to be applied to a portable negative pressure treatment device that sucks wounds and improves the granulation effect, which is one of the medical devices, a large flow rate and high pressure are essential conditions, along with the thinness of the blower device.

[0015] The present invention proposes a specific configuration for a piezoelectric blower device that can be made thinner, with the aim of being incorporated into thinner and smaller electronic devices, such as mobile terminals, for which continued demand is expected in future social life. [Means for solving the problem]

[0016] The piezoelectric blower according to the present invention incorporates a one-way valve mechanism that actively operates in accordance with the displacement and vibration of a circular diaphragm with a thickness of 100 μm or less, which is displaced and vibrated by a piezoelectric element, inside the center of the diaphragm, and the central axis of the one-way valve mechanism is aligned with the position of maximum and minimum values ​​of a pressure standing wave generated by radial vibration (longitudinal wave) of a fluid generated in a cylindrical cavity formed including the diaphragm. The piezoelectric element attached to the diaphragm surface on the fluid outlet side of the one-way valve mechanism is cylindrical and has a shape with a fluid introduction hole in the center, and the central axis of the fluid introduction hole is aligned with the position of maximum and minimum values ​​of the pressure standing wave, similar to the one-way valve mechanism. The pressure standing wave generated in the cylindrical cavity is selectively switched between open and closed in synchronization with the displacement vibration by the one-way valve incorporated in the diaphragm, and the high-pressure phase fluid in the cylindrical cavity is sent out to the outside through the fluid introduction hole formed in the center of the piezoelectric element. The diaphragm vibrates with its circular edge bonded and fixed, and the application of voltage to a piezoelectric element attached to the thinned diaphragm causes bending displacement, which induces the discharge of fluid to the outside. In order to form these structures in a thin area, the diaphragm with one-way valve function is manufactured by diffusion bonding three layers of metal foil material. The cylindrical cavity and the part that becomes the intake flow path are also similarly formed as a single unit by diffusion bonding using metal foil material. An insulating layer and a conductive layer are formed on the surface of the diaphragm, which are electrically connected to the piezoelectric element by wire bonding, and a fluid path that connects to the flow path substrate is also formed separately on the surface of the diaphragm. Effect of the Invention

[0017] In the present invention, the one-way valve can maintain its ability to follow the increase in drive frequency that accompanies size reduction, and therefore the valve can be built into thin, small electronic devices, such as mobile terminals, to accommodate a variety of applications that require high flow rates and high pressure.

[0018] Furthermore, by forming the main body by diffusion bonding of metal foil material, the thickness of the piezoelectric blower device can be made much thinner than in the conventional example, which increases the degree of freedom in mounting. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view showing the appearance of a typical product shape of a piezoelectric blower device 1 according to the present invention. [Figure 2A] FIG. 2A is a front view of the piezoelectric blower device 1 according to the present invention. [Figure 2B] FIG. 2B is a schematic cross-sectional view of the piezoelectric blower device 1 according to the present invention as viewed from the direction of the arrow A. [Figure 2C] FIG. 2C is a schematic cross-sectional view of the piezoelectric blower device 1 according to the present invention as viewed from the direction of the arrow B. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing an enlarged view of the periphery of a one-way valve disposed in the piezoelectric blower device 1 according to the present invention. [Figure 4] 4 is an exploded perspective view of the piezoelectric blower device 1 according to the present invention, showing the shapes of the valve holes 14A-1 of the first valve hole layer 14A shown in the exploded perspective view as a partially enlarged view. [Figure 5A] FIG. 5A is a schematic cross-sectional view illustrating the closing of the one-way valve. [Figure 5B] FIG. 5B is a schematic cross-sectional view illustrating the one-way valve being opened. [Figure 6] FIG. 6 is a schematic diagram showing the principle of diffusion bonding. [Figure 7] FIG. 7 shows an example of the thickness configuration of the diaphragm 14 laminated and bonded using the diffusion bonding principle. [Figure 8] FIG. 8 is a perspective view showing a preferred mounting method for the piezoelectric blower device 1 according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0020] FIG. 1 shows a piezoelectric blower device according to the present invention. 11 is a perspective view showing a typical external shape of the blower body 10. A circular piezoelectric element 30 having a fluid conducting hole 31 at the center is attached to a diaphragm surface 14 (not shown) of a substantially rectangular blower body 10 formed by multilayer bonding of metal foil materials by a metal diffusion bonding method. Two voltage application lands 41, 42 for driving the piezoelectric element 30 are provided in diagonal areas bonded to the substantially rectangular blower body 10 and not displaced or vibrated as the diaphragm 14. One of them is a GND land 41, which is electrically connected to a negative electrode surface 30B (not shown) formed on the lower surface of the piezoelectric element 30 and the substantially rectangular blower body 10 made of a conductive metal material. The other is a SIG land 42, which is formed by plating Au or printing a pattern of Ag on the insulating layer 20, and the positive electrode surface 30A of the piezoelectric element 30 and the SIG land 42 are electrically connected by a thin bonding wire 50 made of Au or Al / Si material. Also, an INLET hole 60 for sucking in and introducing fluid into the blower body is formed in an area that is joined to the approximately rectangular blower body 10, does not displace and vibrate as the diaphragm 14, and does not have the two voltage application lands 41 and 42. As in this embodiment, a through hole 70 may be formed in advance in an area that does not affect the blower function, and used as a positioning hole when incorporating into a product. By connecting a power supply device (not shown) to the two voltage application lands 41 and 42 and applying an AC voltage, the piezoelectric element 30 repeatedly compresses and expands, pressurizing, rectifying, and sending out the fluid according to a principle described later, and the fluid is discharged in the direction of the arrow from the fluid conducting hole 31 drilled in the center of the piezoelectric element 30 as an outlet.

[0021] 2A, 2B, 2C, and 3 show a piezoelectric blower device according to the present invention. 1 3 shows a schematic cross-sectional view of the one-way valve, and in particular, FIG. 3 shows a detailed structure of the one-way valve. In addition, in order to better understand the configuration of the present invention, FIG. 4 shows a typical piezoelectric blower device according to the present invention. 1 FIG. Fig. 2B or Fig. 2C shows a cross-sectional view taken along the arrow in Fig. 2A. The roughly rectangular blower body 10 is roughly composed of four blocks, a diaphragm layer 14, a cavity layer 13, a node layer 12, and a flow path layer 11, when viewed from the cross-sectional direction as shown in Fig. 2B or Fig. 2C. These four layers are integrated by bonding metal foil materials using a metal diffusion bonding method described below. Two node holes 12A are formed in the node layer 12 arranged below the cavity layer 13, and a flow path is connected from the INLET hole 60 through the flow path groove 11A, and a fluid path is further connected to the cavity 13A. The diaphragm layer 14 is further composed of three thin layers. From the bottom in Fig. 3, they are the valve hole layer 14A, the flap valve layer 14B, and the valve swing space layer 14C, and all of them are integrated together by metal diffusion bonding except for the flap valve 14B-1, which is part of the flap valve layer 14B. The valve hole layer 14A is formed as a layer having four fan-shaped valve holes 14A-1. The flap valve 14B-1 has a through hole 14B-2 formed in the center, which does not overlap with the four fan-shaped valve holes 14A-1 of the valve hole layer 14A. The flap valve 14B-1 is forced to swing between the valve swing spaces 14D-1 in two operation modes described below, and functions as a one-way valve. The laminated bonding of the metal foil material creates a structure similar to that of a bulk material as a thin diaphragm 14 while incorporating a one-way valve mechanism.

[0022] Metal diffusion bonding is a great feature of the technology that can form hollow structures at low cost and in a general purpose manner. In the field of MEMS (Micro Electro Mechanical System), it is well known that semiconductor silicon materials are used to manufacture microstructures and electronic circuits for miniaturization. When microstructures operate at high frequencies, semiconductor silicon materials are not necessarily suitable. In terms of the mechanical properties of materials, for example, SUS304 has three times higher bending strength than single crystal silicon. SUS304 also has the advantage of being less susceptible to cracks because of its higher ductility. It is easy to imagine that in devices that undergo repeated elastic deformation at high frequencies, it is commercially desirable to select metal materials within the range where fine processing is possible in order to avoid damage such as cracks. The piezoelectric element 30 is adhesively fixed to the surface of the diaphragm 14. A non-conductive thermosetting epoxy resin adhesive or the like is selected as the adhesive 80. The lower electrode 30B of the piezoelectric element 30 has a rough surface, and when pressure-bonded, an electrical connection is maintained microscopically with the surface of the diaphragm 14. Meanwhile, the upper electrode 30A of the piezoelectric element 30 is electrically connected to the SIG land 42 by the bonding wire 50 described above.

[0023] 5A and 5B are schematic cross-sectional views for explaining the opening and closing of the one-way valve by the displacement vibration of the diaphragm 14. FIG. 5A shows a case where a negative potential is applied to the upper electrode 32 of the piezoelectric element 30, causing the piezoelectric element 30 to expand in the radial direction, causing distortion deformation between the piezoelectric element 30 and the diaphragm 14 restrained by the adhesive 80, and displacing the diaphragm 14 in the upward direction in the figure. FIG. 5B shows a case where a positive potential is applied to the upper electrode 32 of the piezoelectric element 30, causing the piezoelectric element 30 to compress in the radial direction, causing distortion deformation between the piezoelectric element 30 and the diaphragm 14 restrained by the adhesive 80, and displacing the diaphragm 14 in the downward direction in the figure. At this time, the flap valve 14B-1 built in the diaphragm 14 is forced to swing in the opposite direction to the displacement direction of the diaphragm 14. When the diaphragm 14 is displaced upward as shown in Fig. 5A, the flap valve 14B-1 swings to the valve oscillation space layer side 14C-1 and engages with the first valve hole layer 14A, preventing fluid from being sent to the outside. When the diaphragm 14 is displaced downward as shown in Fig. 5B, the flap valve 14B-1 swings to the valve oscillation space 14D-1 side and engages with the piezoelectric element 30, allowing fluid to be sent to the outside.

[0024] The flap valve 14B-1 is made of an extremely thin metal foil material of 10 μm or less, and is formed as a part of the flap valve layer 14B. Metal rolling processing has been developing year by year, and it is possible to manufacture a uniform foil material of several μm thickness with small surface roughness by rolling. Piezoelectric blower device according to the present invention 1 If an attempt is made to reduce the size based on this structure, the drive frequency of the diaphragm 14 will become higher, and it is anticipated that it will be necessary to select a thinner material in consideration of the compliance of the flap valve 14B-1. The flap valve 14B-1 is fixed between the valve hole layer 14A and the valve oscillation space layer 14C by metal diffusion bonding, so that the elasticity of the metal material allows the peripheral part including the through hole 14B-2 to oscillate. The structure in which the valve body opens and closes following the pressure difference in the conventional example is more applicable to high frequency drive by forcibly oscillating the flap valve 14B-1 by the displacement vibration of the diaphragm 14.

[0025] FIG. 6 is a piezoelectric blower device according to the present invention. 1 This is a schematic diagram showing the principle of metal diffusion bonding, which is the basis for the production of the above. The diagram is taken from "Q&A Diffusion Bonding," published by Sanpo Publishing in 1993, written by Ohashi Osamu. JIS defines diffusion bonding as "a method of bonding parent materials by bringing them into close contact, applying pressure at a temperature below the melting point of the parent materials to the extent that plastic deformation is minimized, and utilizing the diffusion of atoms that occurs at the bonding surface." Diffusion bonding is the perfection of the bond (removal of surface coating, bonding of bonding surfaces), and is derived from a bonding mechanism that utilizes the diffusion of metal atoms, and is different from methods such as friction welding, forge welding, hot pressure welding, and cold pressure welding. It is well known that when clean metals approach each other at the atomic level, an atomic bond can easily be formed at room temperature without melting. Commercially, this phenomenon is commonly used to bond metals by stacking metal materials with small surface roughness together and heating and pressurizing them in a vacuum. When heated to a certain temperature, the oxide film on the surface of the metal material disappears through diffusion, exposing the metal atoms. Pressurization also causes creep of the metal crystals, and the distance between the metals at the bonding surface shrinks, atomic diffusion progresses, and the bond is completed. FIG. 6A shows a metal surface covered with an oxide film before heating. FIG. 6B shows the process in which the oxide film disappears and the irregularities begin to undergo plastic deformation. Figure 6(C) shows the process of creep deformation. FIG. 6(D) shows the process in which the voids disappear due to diffusion. There are several advantages to the diffusion bonding method, including: 1) after bonding is complete, the bonded surface disappears and the structure becomes close to bulk. 2) It is possible to form hollow structures. 3) There is a high degree of freedom in the selection of bonding materials in terms of metal type. 4) It is easy to create microstructures by selecting thin rolled materials with small surface roughness.

[0026] FIG. 7 shows an example of the thickness configuration of the diaphragm 14 laminated and bonded using the diffusion bonding principle. As described above, the diaphragm 14 has a built-in one-way valve mechanism, so it is bonded by stacking multiple metal foil materials that have been processed into a shape that satisfies the function by etching or fine pressing. Since the flap valve 14B-1 part is not pressurized from the outside, it remains swingable between the valve hole layer 14A and the valve swing space layer 14C-1 even after diffusion bonding. For example, when SUS304 is selected as the metal material, it is relatively easy to obtain and can be obtained inexpensively with a small surface roughness. The thickness is generally in the range of t5μm to t1000μm, and the thickness of each layer that constitutes the diaphragm can be, for example, as follows. Valve hole layer 14A: t30μm Flap valve layer 14B: t5μm Valve swing space layer 14C: t30μm In this example, the thickness of the diaphragm layer 14 after diffusion bonding is t65 μm, and the thickness can be adjusted in a direction that maximizes the displacement of the diaphragm 14. The thickness of each layer is not limited to this, and various thicknesses can be selected depending on the purpose of device design.

[0027] FIG. 8 is a piezoelectric blower device according to the present invention. 1 Since the main object of the present invention is to mount the piezoelectric blower device in a thin, small electronic device such as a mobile terminal, 1 The mounting method of the piezoelectric element 30 with the fluid conducting hole 31, the INLET hole 60, and the two voltage application lands 41 and 42 for driving the piezoelectric element 30 are provided on the surface of the same diaphragm 14 in the substantially rectangular blower body 10 as shown in Fig. 1 above. Here, a flow channel substrate having a fluid flow channel inside and an electronic circuit formed on the surface 3 Piezoelectric Blower Device 1 A piezoelectric blower device according to the present invention is prepared separately. 1 The, 4 By mounting via a low height fluid module 0 It can be established as follows. 4For example, a thermosetting adhesive sheet having adhesive properties is selected. Piezoelectric blower device 1 The fluid conducting hole 31 and the INLET hole 60 formed in the flow path substrate 3 The flow path formed inside is bonded to prevent leakage around the hole, and is connected as a fluid path. Two voltage application lands 41 and 42 for driving the piezoelectric element 30 are attached to the flow path substrate by conductive paste 5, metal micro springs, etc. 3 The substrate is connected to an electrical wiring pattern formed on the surface. 3 The flow path built into the filter is fabricated using the metal diffusion bonding method described above, with film substrates with wiring patterns bonded to the top and bottom of the filter. This configuration is considered to be suitable for incorporation into small electronic devices, as it is both thin and strong. The film substrate may be a multi-layer substrate, and the piezoelectric blower device according to the present invention 1 Instead of mounting only the pressure sensor die 3A, resistor chip 3B, capacitor chip 3C, amplifier circuit 3D, connector 3E, system LSI 3F, etc., on the film substrate at the same time by high density wiring, 0 It can be formed as follows. As shown in the figure, the piezoelectric blower device according to the present invention has a different internal structure. 1 A piezoelectric valve device manufactured using the same manufacturing method as 2 If the above configuration is implemented, it becomes easy to implement a small, thin cuff-pressurization type blood pressure monitor module in small electronic devices such as mobile terminals, in particular in wristwatch-type information terminals. [Industrial Applicability]

[0028] Piezoelectric blower device manufactured according to the present invention 1 For example, in the field of information devices, it is conceivable that industrial applications of this technology could include incorporating functions for measuring blood pressure or atmospheric CO2 and dust concentrations in mobile terminals for constant monitoring. For example, in medical applications, industrial applications such as negative pressure therapy devices that emphasize mobility, drainage, pressure cuffs, sleep apnea prevention devices, and respiratory support devices are conceivable. For example, in the automotive field, industrial applications include preventing condensation inside headlights, removing water droplets from rearview cameras, preventing drowsiness at the wheel, and evaporating air fresheners. For example, in the personal field, industrial applications are conceivable for pocket fans and jackets with built-in air-cooling devices. [Explanation of symbols]

[0029] 0 Low Height Fluid Module 1 Piezoelectric Blower Device 2 Piezoelectric Valve Device 3 Flow Channel Substrate 3A Pressure Sensor Die 3B Resistor Chip 3C Capacitor Chip 3D Amplifier Circuit 3E Connector 3F System LSI 4 Maza 5 Conductive paste (metal micro spring) 10 Blower body 11 Flow path layer 11A Flow channel 12 Node Layer 12A Node Hole 13 Cavity layer 13A Cavity 14 Diaphragm 14A Valve hole layer 14A-1 Valve hole 14B Flap valve layer 14B-1 Flap valve 14B―2 Flap valve hole 14C Valve rocking space layer 14C-1 Valve swing space 20 Insulating layer 30 Piezoelectric element 31 Fluid Through Hole 30A top electrode 30B Bottom electrode 41 GND Land Land for 42 SIG 50 Bonding Wire 60 INLET HOLES 70 Through hole 80 Adhesive

Claims

1. A thin piezoelectric blower device having a flap valve of 10 μm or less in thickness and a valve oscillation space above the flap valve, which is provided inside the center of a diaphragm of 100 μm or less in thickness and made of three layers laminated and bonded with metal foil, which moves repeatedly due to the vibration of a piezoelectric element, and which forcibly oscillates the flap valve by the repeated movement of the diaphragm to straighten the flow of fluid, and which is configured so that the center of a circular cavity formed directly below the diaphragm, the moving center of the flap valve built into the diaphragm, and a hole drilled in the center of the piezoelectric element are aligned, and the fluid is sent out in one direction to the outside through the hole drilled in the center of the piezoelectric element, and which is characterized in that an insulating layer and a conductive layer are formed on the surface of the diaphragm to provide an electrical connection land for driving the piezoelectric element, and at the same time, a fluid inlet is provided on the surface of the diaphragm.

2. The thin piezoelectric blower device according to claim 1, characterized in that a laminated diaphragm having a thickness of 100 μm or less and incorporating a flap valve is made by laminating three layers of metal foil and integrally manufacturing the laminated diaphragm by a metal diffusion bonding method.

3. The thin piezoelectric blower device as shown in claims 1 and 2, characterized in that the circular cavity and fluid introduction flow path constituting the blower body are also manufactured integrally by laminating metal foils and using a metal diffusion bonding method.

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