JP7618124B2 - Surface mountable thin piezoelectric blower device - Google Patents

Description

The present invention relates to the structure of a thin piezoelectric blower device suitable for incorporation into small electronic devices such as mobile terminals.

Piezoelectric blower devices use piezoelectric elements as actuators to operate a diaphragm at a high-frequency driving frequency to blow out gas, and many patent applications have been filed for configurations that have been devised with the aim of making them smaller, including the following configuration examples: (Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5)

Patent document 1 shows 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 forming a pump chamber, and an elastic buffer being provided at the boundary 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 fluid to flow in or out through the second opening.

However, in the configuration shown in Patent Document 1, unless the relationship pump volume, which changes with the operation of the displacer, >> buffer internal volume holds, a large pressure difference will 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 because the fluid is discharged by the restoring force of the buffer, there is also a problem that the back pressure on the outlet side is small.

Patent document 2 shows an example of a fluid pump that includes an actuator that displaces a movable wall such as a piston or a diaphragm, a drive means that drives and controls the actuator, a pump chamber whose volume can be changed by the displacement of the movable wall, an inlet flow path that allows working fluid to flow into the pump chamber, and an outlet flow path that allows working fluid to flow out of the pump chamber, where the outlet flow path communicates with the pump chamber during pump operation, the combined inertance value of the inlet flow path is smaller than the combined inertance value of the outlet flow path, and the inlet flow path includes 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, the drive means includes a period control means that changes the motion period of the movable wall, and the period control means drives the actuator so that the pump chamber volume compression process of the movable wall starts when the pressure in the pump chamber reaches absolute zero atmospheres.

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

Patent document 3 shows an example of a piezoelectric microblower that includes a first wall of a blower body that forms a blower chamber between itself and a diaphragm, a first opening formed in a portion of the first wall that faces the center of the diaphragm and connects the inside and outside of the blower chamber, a second wall that is spaced apart from the first wall on the opposite side of the blower chamber across the first wall, a second opening formed in a portion of the second wall that faces the first opening, and an inflow passage formed between the first and second wall, the outer end of which is connected to the outside and the inner end of which is connected to the first and second openings, and a central space having an opening area larger than the first and second openings is formed at the inner end of the inflow passage connected to the first and second openings, and the portion of the first wall that faces the central space vibrates as the diaphragm is displaced.

However, while the configuration shown in Patent Document 3 can deliver compressible fluid by inertial force, there is no check valve, so there is a large fluctuation in flow rate in response to external pressure, and there is a problem in that the product functionality is extremely limited in applications in which the 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.

In Patent Document 4, a pump chamber is provided that is located between the first and second vibration plates and is defined by the first and second vibration plates and the peripheral wall portion, and a driver that generates pressure fluctuations in the pump chamber by bending and vibrating the first and second vibration plates. The first vibration plate is provided with a first hole portion that is arranged in a position that overlaps with the axis when viewed along the extension direction of an axis perpendicular to the center of the first vibration plate and the center of the second vibration plate and is not provided with a check valve, and at least one of the first and second vibration plates is provided with a second hole portion that is arranged in a position that does not overlap with the first hole portion when viewed along the extension direction of the axis and is provided with a check valve, and the first and second vibration plates are provided with a pump chamber that is located between the first and second vibration plates and the peripheral wall portion. An example of a fluid pump is shown in which at least one of the vibration plates is further provided with a third hole portion that is located outside the area in which the second hole portion is provided when viewed along the direction of extension of the axis while centering on the axis line, and that does not have a check valve attached.

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 is a problem that it cannot be installed in a thin mobile terminal assumed for an application that requires the delivery of a large flow rate and high pressure of an incompressible fluid.

In Patent Document 5, 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, the 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 motion of the driven end wall, thereby generating, in use, a displacement vibration of the driven end wall in a direction substantially perpendicular to the end wall, with an annular node between the 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 opening and extending through the pump body, and a valve disposed in at least one of the first opening and the second opening, in which, in use, the displacement vibration generates 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.

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 large amplitude pressure vibrations near the center of the cylindrical cavity. Compared to Patent Documents 3 and 4, this is an excellent proposal for a principle configuration for delivering compressible fluid at high pressure. However, there are the following problems when trying to manufacture a smaller blower based on this configuration. The first 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) that is configured based on the principle of being driven by differential pressure cannot keep up with the resonance frequency, and it may not be able 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.

Patent No. 3035854 Patent No. 5003700 Patent No. 4873014 Patent No. 6769568 Special table 2012-528980 publication

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 fluid with a simple configuration, and is certainly a technical proposal that can be adapted to small electronic devices. However, these proposals are not sufficient for application in 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 building a function to measure blood pressure by pressurizing a cuff into a mobile terminal or a watch-type mobile device, or similarly when building a function to suck in and detect or count pollen or air pollutants into a mobile terminal or a watch-type mobile device, or when applying to a portable negative pressure treatment device that sucks in wounds and improves granulation formation, which is one type of medical device, a high flow rate and high pressure are essential conditions, along with a thin blower device.

The present invention proposes a specific configuration for a piezoelectric blower device that can be made thinner, with the aim of incorporating it into thinner, smaller electronic devices, such as mobile terminals, which are expected to see continued demand in future social life.

The piezoelectric blower according to the present invention incorporates a one-way valve mechanism that actively operates in response to the displacement and vibration of a circular diaphragm with a thickness of 100 μm or less that is displaced and vibrated by a piezoelectric element, and the central axis of the one-way valve mechanism is aligned with the maximum and minimum values of the pressure standing wave generated by the radial vibration (longitudinal wave) of the fluid generated in a cylindrical cavity formed including the diaphragm. The piezoelectric element attached to the diaphragm surface that is the fluid outlet side of the one-way valve mechanism is cylindrical and has a shape with a fluid conducting hole in the center, and the central axis of the fluid conducting hole is aligned with the 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 and vibration by the one-way valve built into the diaphragm, and the high-pressure phase fluid in the cylindrical cavity is sent to the outside through the fluid conducting 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 suction 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 is 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.

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

In addition, 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 conventional examples, allowing for greater freedom in mounting.

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. FIG. 2A is a front view of the piezoelectric blower device 1 according to the present invention. FIG. 2B is a schematic cross-sectional view of the piezoelectric blower device 1 according to the present invention as viewed in the direction of the arrow A. FIG. 2C is a schematic cross-sectional view of the piezoelectric blower device 1 according to the present invention as viewed in the direction of the arrow B. FIG. 3 is an enlarged schematic cross-sectional view of the periphery of a one-way valve disposed in the piezoelectric blower device 1 according to the present invention. 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. FIG. 5A is a schematic cross-sectional view illustrating the closing of the one-way valve. FIG. 5B is a schematic cross-sectional view illustrating the one-way valve being opened. FIG. 6 is a schematic diagram showing the principle of diffusion bonding. FIG. 7 shows an example of the thickness configuration of the diaphragm 14 laminated and bonded using the diffusion bonding principle. FIG. 8 is a perspective view showing a preferred mounting method for the piezoelectric blower device 1 according to the present invention.

1 is a perspective view showing a typical external shape of a piezoelectric blower device 1 according to the present invention. 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 multi-layer bonding of metal foil materials by metal diffusion bonding. Two voltage application lands 41 and 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 to the substantially rectangular blower body 10 made of a conductive metal material. The other is a land 42 for SIG, 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 land 42 for SIG are electrically connected by a thin bonding wire 50 made of Au or Al/Si. Also, in an area where the diaphragm 14 does not displace and vibrate and where the two voltage application lands 41 and 42 are not formed, which is joined to the substantially rectangular blower body 10, an INLET hole 60 is formed to suck in a fluid and introduce it into the blower body. 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, and the fluid is pressurized, rectified, and sent out according to the principle described below, and is discharged in the direction of the arrow from the fluid conducting hole 31 drilled in the center of the piezoelectric element 30 as the OUTLET.

2A, 2B, 2C, and 3 are schematic cross-sectional views of the piezoelectric blower device 1 according to the present invention, and in particular, Fig. 3 shows a detailed structure of a one-way valve. In order to better understand the configuration of the present invention, Fig. 4 shows an exploded perspective view of a typical piezoelectric blower device 1 according to the present invention.
Fig. 2B and Fig. 2C show cross-sectional views taken along the arrows 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 a valve hole layer 14A, a flap valve layer 14B, and a valve swing space layer 14C, and all layers are integrated together by metal diffusion bonding except for a flap valve 14B-1, which is a part of the flap valve layer 14B.
The valve hole layer 14A is formed as a layer having four sector-shaped valve holes 14A-1. The flap valve 14B-1 has a through hole 14B-2 formed at the center, which does not overlap with the four sector-shaped valve holes 14A-1 of the valve hole layer 14A. The flap valve 14B-1 is forced to swing within the valve swing space 14D-1 by 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.

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 fine structures and electronic circuits for miniaturization. When fine structures 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 the bending strength of 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.

5A and 5B are schematic cross-sectional views explaining the opening and closing of the one-way valve by the displacement vibration of the diaphragm 14. In FIG. 5A, 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, and distortion occurs between the piezoelectric element 30 and the diaphragm 14 restrained by the adhesive 80, causing the diaphragm 14 to displace upward in the figure. In FIG. 5B, 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 between the piezoelectric element 30 and the diaphragm 14 restrained by the adhesive 80, causing the diaphragm 14 to displace downward in the figure. At this time, the flap valve 14B-1 built into 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 Figure 5A, the flap valve 14B-1 swings to the valve swing space layer side 14C-1 and engages with the first valve hole layer 14A, making it impossible to send fluid to the outside. When the diaphragm 14 is displaced downward as shown in Figure 5B, the flap valve 14B-1 swings to the valve swing space 14D-1 side and engages with the piezoelectric element 30, making it possible to send fluid to the outside.

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 is improving year by year, and it is possible to manufacture a uniform foil material of a few μm in thickness with small surface roughness by rolling. When attempting to reduce the size based on the structure of the piezoelectric blower device 1 according to the present invention, the driving frequency of the diaphragm 14 becomes high, and it is expected that it will be necessary to select a thinner material in consideration of the tracking ability 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 elastic force of the metal material allows the peripheral portion 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.

Fig. 6 is a schematic diagram showing the principle of metal diffusion bonding, which is the basis for manufacturing the piezoelectric blower device 1 according to the present invention. The figure is taken from "Q&A Diffusion Bonding" published by Sanpo Publishing in 1993, author: Osamu Ohashi. JIS defines diffusion bonding as "a method of bonding by bonding the base materials together, applying pressure to the extent that plastic deformation is minimized under temperature conditions below the melting point of the base materials, and utilizing the diffusion of atoms that occurs on the bonding surface." Diffusion bonding is the perfection of the bonded part (removal of the surface coating, bonding of the bonding surfaces), and originates 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 two clean metals come close to 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 in a vacuum, heating and pressurizing them. 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, reducing the distance between the metals at the bonding surface, and atomic diffusion progresses, completing the bond.
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.
FIG. 6C shows the process of creep deformation.
FIG. 6D 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 bonding surface disappears and the structure becomes close to bulk. 2) Hollow structures can be formed. 3) There is a high degree of freedom in choosing bonding materials for different metal types. 4) It is easy to create microstructures by selecting thin rolled materials with small surface roughness.

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 multiple metal foil materials that have been processed into a shape that satisfies the function by etching or fine pressing are laminated and bonded. Since the flap valve 14B-1 portion is not pressurized from the outside, it remains able to swing between the valve hole layer 14A and the valve swing space layer 14C-1 even after diffusion bonding. For example, if SUS304 is selected as the metal material, it is relatively easy to obtain and has a small surface roughness, so it can be obtained inexpensively. The thickness is generally in the range of t5 μm to t1000 μm, 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: t 5 μm
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.

Fig. 8 is a schematic perspective view showing a mounting method of the piezoelectric blower device 1 according to the present invention. Since the main object of the present invention is to mount it in a thin, small electronic device such as a mobile terminal, the mounting method of the piezoelectric blower device 1 must also take into consideration the need to make it thinner. As shown in Fig. 1 above, the substantially square blower body 10 has a piezoelectric element 30 with a fluid conducting hole 31, an INLET hole 60, and two voltage application lands 41 and 42 for driving the piezoelectric element 30, which are provided on the surface of the same diaphragm 14.
Here, a flow path substrate 3 having a fluid flow path inside and an electronic circuit formed on the surface is prepared separately from the piezoelectric blower device 1 , and the piezoelectric blower device 1 of the present invention is mounted via a spacer 4 to form a low height fluid module 0. For example, a thermosetting adhesive sheet having adhesive properties is selected as the spacer 4. The fluid conducting hole 31 and the INLET hole 60 formed in the piezoelectric blower device 1 are bonded to the flow path formed inside the flow path substrate 3 so as not to leak around the holes, and are connected as a fluid path. In addition, the two voltage application lands 41 and 42 for driving the piezoelectric element 30 are connected to the electrical wiring pattern formed on the surface of the flow path substrate 3 by conductive paste 5, metal micro springs, etc. A configuration in which the flow path built into the flow path substrate 3 is manufactured by the above-mentioned metal diffusion bonding, and film substrates with wiring patterns are bonded above and below it is considered to be preferable for mounting on small electronic devices because it is both thin and strong.
The film substrate may be a multi-layer substrate, and instead of mounting only the piezoelectric blower device 1 according to the present invention, for example, a pressure sensor die 3A, a resistor chip 3B, a capacitor chip 3C, an amplifier circuit 3D, a connector 3E, a system LSI 3F, etc. can be mounted simultaneously on the film substrate by high-density wiring to form a low-height fluid module 0 .
As shown in the figure, although the internal structure is different, if a piezoelectric valve device 2 manufactured by the same manufacturing method as the piezoelectric blower device 1 of the present invention is also installed, it can be easily installed as a small, thin cuff pressure type blood pressure monitor module in small electronic devices such as mobile terminals, in particular wristwatch-type information terminals.

The piezoelectric blower device 1 manufactured according to the present invention can be used industrially, for example, in the information equipment field, by incorporating functions for measuring blood pressure or atmospheric CO2 concentration or dust concentration into a mobile terminal 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.

0 Low Height Fluid Module
1. Piezoelectric blower device
2. Piezoelectric valve device
3 Flow path board 3A Pressure sensor die 3B Resistor chip 3C Capacitor chip 3D Amplifier circuit 3E Connector 3F System LSI
4 spaces
5. Conductive paste (metal micro spring)
REFERENCE SIGNS LIST 10 Blower body 11 Flow path layer 11A Flow path groove 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 swing space layer 14C-1 Valve swing space 20 Insulating layer 30 Piezoelectric element 31 Fluid conducting hole 30A Upper electrode 30B Lower electrode 41 GND land 42 SIG land 50 Bonding wire 60 INLET hole 70 Through hole 80 Adhesive

Claims (3)

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