Conversion element member, conversion element module with them, and electronic apparatus

Abstract

To provide a conversion element module capable of suppressing deterioration of a characteristic of an electronic apparatus even in the case where waterproofness of the electronic apparatus is enhanced, and a water pressure is applied, and provide the electronic apparatus.SOLUTION: A conversion element member 1 comprises: a MEMS microphone 2A as a conversion element 2 having an open 22 that functions as a vent port and / or a vent sound port; and a waterproof film 3. A conversion element includes an outer front surface 23 onto which the open is formed. The waterproof film blocks the open to the outer front surface of the conversion element, and is bonded with a bonding part 41 having a shape surrounding the open in view from a direction vertical to the outer front surface, In view of the direction, a non-bonding part 31 of the waterproof film defined as a part surrounded by the bonding part includes a region overlapped with the outer front surface in view of the direction, and a separation distance D1 between the waterproof film and the outer front surface in the region is 0.01 to Xmm. The X is a depression amount of a probe of which reaction force of a film is maximum, in a depression test to the waterproof film conformed to a regulation of a piercing strength test of JIS Z1707.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The present invention relates to a conversion element member including a conversion element having an opening that can function as a ventilation port and / or a sound passage port, and a waterproof film that prevents water intrusion. The present invention also relates to a conversion element module and an electronic device including the above conversion element member.

Background Art

[0002] The housing of an electronic device may be provided with an external circulation port that is an opening through which sound and gas can pass. For example, electronic devices such as wearable devices including smartwatches, smartphones, mobile phones, and cameras have a voice function, and their housings are provided with external circulation ports through which sound can pass. Further, the electronic device includes a voice conversion unit including an acoustic conversion element such as a microphone and a speaker inside the housing. The acoustic conversion element is an element that converts an electrical signal and sound, and has an opening that functions as a sound passage port on its outer surface. The voice conversion unit is housed inside the housing so that sound can be transmitted through the external circulation port between the voice conversion unit and the outside. In addition, an electronic device including a gas sensor such as a pressure sensor includes a housing provided with an external circulation port through which gas can pass, and the electronic device includes a characteristic conversion unit including a characteristic conversion element that converts the characteristics of gas and an electrical signal inside the housing. The above characteristic conversion element has an opening that functions as a ventilation port on its outer surface. The characteristic conversion unit is housed inside the housing so that gas can flow through the external circulation port between the characteristic conversion unit and the outside. On the other hand, water intrusion into the voice conversion unit and the characteristic conversion unit that generally have electronic circuits must be prevented. For this purpose, conventionally, a waterproof film that prevents water intrusion has been attached to the housing so as to block the external circulation port.

[0003] Patent Document 1 discloses a polytetrafluoroethylene (hereinafter referred to as "PTFE") porous film that can be used as a waterproof film.

Prior Art Documents

Patent Documents

[0004] Patent Document 1 Japanese Patent Application Laid-Open No. 10-165787 Summary of the Invention Problems to be Solved by the Invention

[0005] Regarding the waterproofness required for electronic devices, conventionally, a temporary waterproofness sufficient to cope with an unexpected drop into shallow water where the device can be easily picked up was sufficient. However, currently, for example, a high level of waterproofness is often required, such as enabling the functions of a device, including its audio function, to be used with normal characteristics even after the electronic device has been used in water at a depth of several meters for a certain period of time or repeatedly. Also, for an electronic device equipped with an audio function, it is important to ensure not only waterproofness but also sound transmission characteristics. However, regarding a waterproof film, there is a trade-off relationship between waterproofness and sound transmission, and it is not easy to improve the waterproofness of the waterproof film while maintaining sound transmission. These points are not considered in Patent Document 1.

[0006] An object of the present invention is to provide a technology that enhances the waterproofness of an electronic device and can suppress a decrease in the performance of the electronic device even when water pressure is applied. Means for Solving the Problems

[0007] The present invention includes a conversion element having an opening that can function as a vent and / or a sound transmission port, and a waterproof film, the conversion element has an outer surface on which the opening is formed, the waterproof film is joined to the outer surface of the conversion element at a joint portion having a shape that closes the opening and surrounds the opening when viewed from a direction perpendicular to the outer surface, a non-joined portion of the waterproof film, defined as a portion surrounded by the joint portion when viewed from a direction perpendicular to the outer surface, has a region that overlaps with the outer surface when viewed from that direction, a conversion element member in which a separation distance D1 between the waterproof film and the outer surface in the region is 0.01 mm or more and X mm or less to provide. However, X is the amount of insertion of the measuring element at which the repulsive force generated in the waterproof film by the insertion of the measuring element becomes maximum when the pushing-in test of the measuring element against the waterproof film is carried out in accordance with the provisions of the piercing strength test defined in Japanese Industrial Standard (JIS) Z1707:1997.

[0008] In another aspect, the present invention the conversion element member of the present invention described above, a circuit board on which the conversion element member is mounted, and a conversion element module comprising the same. to provide.

[0009] In yet another aspect, the present invention a housing provided with an external circulation port through which gas and / or sound can pass, the conversion element member of the present invention housed in the housing, and the conversion element member is an electronic device housed in the housing so that the intrusion of water from the outside of the housing through the external circulation port into the opening is prevented by the waterproof film. to provide.

Advantages of the Invention

[0010] According to the present invention, the waterproof property of an electronic device can be enhanced, and the deterioration of the performance of the electronic device can be suppressed even when water pressure is applied.

Brief Description of the Drawings

[0011]

Figure 1A

Figure 1B

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 7

Figure 8

Figure 9

Figure 10A

Figure 10B

Figure 11

Figure 12

Figure 13

MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments.

[0013] [Conversion element member] An example of the conversion element member of the present invention is shown in FIGS. 1A and 1B. FIG. 1B shows a cross-section B-B shown in FIG. 1A. FIG. 1A shows the conversion element member 1 as viewed from the side of the arrangement surface of the waterproof film 3 in the conversion element 2.

[0014] The conversion element member 1 includes a conversion element 2 and a waterproof film 3. The conversion element 2 included in the conversion element member 1 in FIGS. 1A and 1B is a MEMS microphone 2A which is a kind of acoustic conversion element (acoustic transducer) that converts sound and an electrical signal. The MEMS microphone 2A includes a substrate 21 having an opening (sound passage opening) 22 through which sound can pass. The surface of the substrate 21 where the opening 22 is formed is exposed to the outside without the waterproof film 3 being disposed thereon. In other words, the conversion element 2 has an outer surface 23 where the opening 22 is formed. In this specification, the outer surface 23 of the conversion element 2 means the surface that is exposed to the outside without the waterproof film 3 being disposed thereon. The waterproof film 3 is joined to the outer surface 23 of the conversion element 2 so as to close the opening 22, more specifically, so as to close the opening 22 in the outer surface 23. Further, the waterproof film 3 is joined to the outer surface 23 at a joint portion 41 of the film 3 having a shape surrounding the opening 22 when viewed from a direction perpendicular to the outer surface 23. In the conversion element member 1, a non-joined portion 31 of the waterproof film 3 defined as a portion surrounded by the joint portion 41 when viewed from a direction perpendicular to the outer surface 23 has a region 32 overlapping with the outer surface 23 when viewed from the perpendicular direction. In other words, a part of the non-joined portion 31 of the waterproof film 3 is located between the opening 22 and the joint portion 41 when viewed from a direction perpendicular to the outer surface 23. Further, the separation distance D1 between the waterproof film 3 and the outer surface 23 in the region 32 is 0.01 mm or more and X mm or less. However, X is the amount of depression of the measuring element with respect to the waterproof film 3 when a pushing-in test of the measuring element against the waterproof film 3 is performed in accordance with the provisions of the piercing strength test defined in JIS Z1707:1997, at which the repulsive force generated in the waterproof film 3 by the pushing-in of the measuring element becomes maximum. X corresponds to the maximum amount of deformation that the waterproof film 3 can be deformed within the range of elastic deformation.

[0015] When a water pressure is applied to the waterproof film 3 of the conversion element member 1 in the direction of the conversion element 2, the waterproof film 3 deforms in the direction of the opening 22 at the non-joint portion 31. However, in the conversion element member 1, the upper limit of the separation distance D1 between the waterproof film 3 and the outer surface 23 in the region 32 is limited to X mm or less. Therefore, even when the water pressure applied to the waterproof film 3 is large or when the water pressure is continuously applied to the waterproof film 3, the deformation of the waterproof film 3 is restricted within the range of elastic deformation without reaching plastic deformation by the contact of the deformed waterproof film 3 with the outer surface 23. When the conversion element 2 is an acoustic conversion element, the waterproof film 3 is required to prevent water intrusion while allowing the transmission of sound. Also, in this case, the portion of the waterproof film 3 where sound mainly passes through is the non-joint portion 31. If the non-joint portion 31 of the waterproof film 3 remains in contact with the outer surface 23 even after being released from the water pressure, the sound transmission property of the waterproof film 3 decreases, thereby reducing the sound transmission characteristics of the conversion element member 1. Further, the deformation (permanent deformation) remaining in the waterproof film 3 even after being released from the water pressure reduces the sound transmission property of the waterproof film 3, thereby reducing the sound transmission characteristics of the conversion element member 1. In the conversion element member 1, by restricting the deformation of the waterproof film 3 due to water pressure within the range of elastic deformation, the degree of permanent deformation in the waterproof film 3 can be alleviated, and also, even when the non-joint portion 31 of the waterproof film 3 comes into contact with the outer surface 23 due to the application of water pressure, it is possible to prevent the continuation of such contact after being released from the water pressure.

[0016] JIS Z1707:1997 stipulates a puncture strength test for plastic films for food packaging. If compliance with this regulation is ensured, it is possible to conduct a push-in test to evaluate the repulsive force generated in the waterproof film 3 when a rod-shaped needle (measuring element) is pushed into the waterproof film 3 from one of its surfaces at a constant speed, and the amount of push-in of the measuring element into the waterproof film 3. In the above push-in test, the waterproof film 3 deforms as the measuring element is pushed in. However, when the amount of push-in of the measuring element is small and the deformation of the waterproof film 3 remains within the range of elastic deformation, the repulsive force generated in the waterproof film 3 increases as the amount of push-in increases. Then, when the amount of push-in of the measuring element further increases and the deformation of the waterproof film 3 reaches plastic deformation, the repulsive force generated in the waterproof film 3 decreases (see Figure 2. Figure 2 shows an example of the relationship between the amount of push-in of the measuring element into the waterproof film 3 and the repulsive force generated in the waterproof film 3 due to the push-in of the measuring element). Therefore, the amount of push-in X of the measuring element at which the above repulsive force is maximized corresponds to the maximum amount of deformation that the waterproof film 3 can undergo within the range of elastic deformation. However, the measuring element to be used shall be a cylindrical shape with a diameter of 0.8 mm and a hemispherical shape with a radius of 0.35 mm at one end that is pushed into the waterproof film 3. Also, the push-in speed of the measuring element into the waterproof film 3 shall be 10 mm / min, and the evaluation shall be carried out in an atmosphere of 25 ± 5°C. Note that since the purpose is not to determine the puncture strength of the waterproof film 3, it is not necessary to continuously push in the measuring element until it penetrates the waterproof film 3 in the above push-in test, and the push-in of the measuring element may be stopped at the stage where the amount of push-in X of the measuring element at which the above repulsive force is maximized is obtained. Also, since the value of the puncture strength itself is not the object of evaluation in the above push-in test, it is not necessarily required to conduct tests on five or more test pieces. For example, the amount of push-in X may be obtained by conducting a test on one test piece. Of course, it is also possible to conduct tests on a plurality of test pieces and take the average value of the amount of push-in at which the above repulsive force is maximized obtained for each test piece as the amount of push-in X.

[0017] Further, in the conversion element member 1, the lower limit of the separation distance D1 is set to 0.01 mm or more, whereby it is possible to prevent the vibration of the non-bonded portion 31 of the waterproof film 3 in a state where no water pressure is applied from being hindered by contact with the outer surface 23. Preventing the vibration of the non-bonded portion 31 from being hindered contributes to good sound transmission characteristics as the conversion element member 1.

[0018] In recent years, as represented by wearable devices such as smartwatches, the miniaturization of electronic devices equipped with a voice function has been progressing. In order to cope with the miniaturization of electronic devices, it is inevitable to reduce the area of the waterproof film. According to the study by the present inventors, when the area of the non-bonded portion (sound transmission portion) 31, which is the portion where sound mainly passes through in the waterproof film 3, is reduced, the smaller the distance between the opening 22 of the conversion element 2 and the waterproof film 3, the more the decrease in the sound transmission characteristics of the conversion element member 1 due to the reduction in the area is suppressed, and good sound transmission characteristics can be ensured. From this viewpoint, the separation distance D1 may be 2 mm or less, 1.5 mm or less, 1 mm or less, less than 1 mm, and further may be 0.9 mm or less. Further, the separation distance D1 may be less than or equal to the smaller value selected from the above X mm and 2 mm, less than or equal to the smaller value selected from the above X mm and 1.5 mm, less than or equal to the smaller value selected from the above X mm and 1 mm, and further may be less than or equal to the smaller value selected from the above X mm and 0.9 mm. Further, in order to more reliably suppress the deterioration of characteristics, the separation distance D1 may be 0.9 times or less, 0.8 times or less, 0.7 times or less, and further may be 0.6 times or less of the pushing amount X.

[0019] In the example shown in FIGS. 1A and 1B, the shape of the waterproof film 3 is a circle when viewed from a direction perpendicular to the main surface of the waterproof film 3. However, the shape of the waterproof film 3 is not limited to this example as long as it can close the opening 22 of the conversion element 2 and can be joined to the outer surface 23 at the joint portion 41 having a shape surrounding the opening 22 when viewed from a direction perpendicular to the outer surface 23, and the non-joint portion 31 may have a region 32 overlapping the outer surface 23 when viewed from the above direction. The shape of the waterproof film 3 may be a circle (including a substantially circle), an ellipse (including a substantially ellipse), a polygon including a rectangle and a square, or an irregular shape when viewed from a direction perpendicular to the main surface of the waterproof film 3. The corners of the polygon may be rounded.

[0020] In the example shown in FIGS. 1A and 1B, the shape of the joint portion 41 of the waterproof film 3 is a shape corresponding to the peripheral portion of the film 3 when viewed from a direction perpendicular to the main surface of the waterproof film 3, and more specifically, it is a ring shape. However, the shape of the joint portion 41 is not limited to this example as long as it can join the waterproof film 3 to the outer surface 23 so as to close the opening 22 and has a shape surrounding the opening 22 when viewed from a direction perpendicular to the outer surface 23.

[0021] In the example shown in FIGS. 1A and 1B, the waterproof film 3 is joined to the outer surface 23 by the adhesive portion 4. The adhesive portion 4 usually has the same shape as the joint portion 41 when viewed from a direction perpendicular to the main surface of the waterproof film 3. The adhesive portion 4 may be, for example, an adhesive layer composed of an adhesive and / or an adhesive agent, or a double-sided adhesive tape. When the adhesive portion 4 is a double-sided adhesive tape, the waterproof film 3 can be more reliably joined to the outer surface 23, and the waterproof property of the conversion element member 1 can be further enhanced. Note that the method of joining the waterproof film 3 to the outer surface 23 is not limited to the above example, and the waterproof film 3 may be joined to the outer surface 23 using welding such as thermal welding or ultrasonic welding.

[0022] As the double-sided adhesive tape that can constitute the adhesive part 4, a known double-sided adhesive tape can be used. The base material of the double-sided adhesive tape is, for example, a resin film, non-woven fabric, or foam. The resin that can be used for the base material is not limited, and for example, it is polyester (such as PET), polyolefin (such as polyethylene), or polyimide. For the adhesive layer of the double-sided adhesive tape, various adhesives such as acrylic adhesives and silicone adhesives can be used. Since the bonding force to the waterproof film 3 and / or the outer surface 23 can be improved, it is preferable to use an acrylic adhesive for the adhesive layer. The double-sided adhesive tape may be a heat-sealing tape. The double-sided adhesive tape may be a base-material-less double-sided adhesive tape without a base material.

[0023] In the examples shown in FIGS. 1A and 1B, the waterproof film 3 is joined to the outer surface 23 via the adhesive part 4. In this case, the separation distance D1 can be controlled by the thickness of the adhesive part 4. When the adhesive part 4 is a double-sided adhesive tape, more reliable control of the separation distance D1 becomes possible. However, the method of controlling the separation distance D1 is not limited to this example. For example, as shown in FIG. 3A, the waterproof film 3 may be joined to the outer surface 23 via a spacer 42. In this case, the separation distance D1 can be controlled by the thickness of the spacer 42. The spacer 42 may have the same shape as the joint part 41 when viewed from a direction perpendicular to the main surface of the waterproof film 3. For the joining of the outer surface 23 and the spacer 42, and the joining of the spacer 42 and the waterproof film 3, the adhesive part 4 or welding, etc. can be utilized. In the example shown in FIG. 3A, the spacer 42 and the outer surface 23 are joined via the adhesive part 4. Also, as shown in FIG. 3B, a substrate 21 having a convex part 43 protruding from the outer surface 23 may be used, and the waterproof film 3 may be joined to the outer surface 23 at the convex part 43. In this case, the separation distance D1 can be controlled by the height of the convex part 43. The convex part 43 may have the same shape as the joint part 41 when viewed from a direction perpendicular to the main surface of the waterproof film 3. For the joining of the convex part 43 and the waterproof film 3, the adhesive part 4 or welding, etc. can be utilized. In addition, the above-described various methods may be arbitrarily combined.

[0024] In the example shown in FIGS. 1A and 1B, the shape of region 32, when viewed from a direction perpendicular to the outer surface 23, is a shape surrounded by the joint portion 41 and the opening 22. More specifically, it is a ring shape that is the shape of the gap between the joint portion 41 and the opening 22. However, the shape of region 32 is not limited to this example. Also, in the example shown in FIGS. 1A and 1B, the distance D2 between the joint portion 41 and the opening 22 in region 32 when viewed from a direction perpendicular to the outer surface 23 is larger than the separation distance D1. The distance D2 may be 1.2 times or more, 1.4 times or more, 1.5 times or more, 1.7 times or more, 1.9 times or more, and even 2 times or more of the separation distance D1. Also, the distance D2 may be, for example, 0.5 mm or more, 1.0 mm or more, 1.5 mm or more, 2.0 mm or more, 2.5 mm or more, and even 3.0 mm or more. In these cases, the restriction of the above deformation on the waterproof film 3 deformed by water pressure becomes more reliable. Note that the distance D2 can be defined as the average length (average length when viewed from a direction perpendicular to the outer surface 23) of the portion passing through region 32 on the virtual straight line when the virtual straight line extending parallel to the outer surface 23 from the center of the opening 22 is rotated along the outer surface 23 with the center as the axis. Also, the average length can be defined as 1 / 2 of the sum of the maximum length and the minimum length of the portion passing through region 32 on the virtual straight line. In the example shown in FIGS. 1A and 1B, D2 can be set as 1 / 2 of the difference between the outer diameter and the inner diameter of the ring-shaped region 32. Note that the above minimum length may be 1.2 times or more, 1.4 times or more, 1.5 times or more, 1.7 times or more, 1.9 times or more, and even 2 times or more of the separation distance D1. Also, the above minimum length may be 0.5 mm or more, 1.0 mm or more, 1.5 mm or more, 2.0 mm or more, 2.5 mm or more, and even 3.0 mm or more.

[0025] The area of the non-joint portion 31 of the waterproof film 3 defined as the portion surrounded by the joint portion 41 when viewed from a direction perpendicular to the outer surface 23 is, for example, 19.6 mm 2 or less, 12.6 mm 2 or less, 7.1 mm 2 or less, 4.9 mm 2 or less, 3.1 mm 2 or less, and even 1.8 mm 2The following may be applicable. In the case where the shape of the non-joint portion 31 is circular when viewed from a direction perpendicular to the outer surface 23, the above area corresponds to the areas of the non-joint portions 31 with the diameters of the circles being 5 mm, 4 mm, 3 mm, 2.5 mm, 2 mm, and 1.5 mm, respectively.

[0026] In the examples shown in FIGS. 1A and 1B, the maximum distance between the non-joint portion 31 of the waterproof film 3 and the plane including the outer surface 23 is equal to the separation distance D1. This mode can be achieved, for example, by joining a flat waterproof film 3 without providing convex portions and / or concave portions or the like to the outer surface 23 without deforming it such as sagging. However, the maximum distance between the non-joint portion 31 of the waterproof film 3 and the plane including the outer surface 23 may not be equal to the separation distance D1. Independently of the separation distance D1, the maximum distance may be, for example, 2 mm or less, 1.5 mm or less, 1 mm or less, less than 1 mm, and further 0.9 mm or less. Also, independently of the separation distance D1, the maximum distance may be less than or equal to the smaller value selected from the above X mm and 2 mm, less than or equal to the smaller value selected from the above X mm and 1.5 mm, less than or equal to the smaller value selected from the above X mm and 1 mm, and further less than or equal to the smaller value selected from the above X mm and 0.9 mm.

[0027] The waterproof film 3 is a film that prevents water intrusion while allowing sound transmission. Various known waterproof films can be used for the waterproof film 3. The waterproof film 3 may be subjected to an oil-repellent treatment or a liquid-repellent treatment.

[0028] The waterproof film 3 is made of a resin such as polyester (PET, etc.), polycarbonate, polyethylene, polyimide, PTFE, polyurethane, silicone, etc. However, the resin constituting the waterproof film 3 is not limited to the above examples. As the material of the waterproof film 3, PTFE is preferable. The film made of PTFE (PTFE film) has a good balance between mass and strength. An elastomer film can be excluded from the waterproof film 3. When the waterproof film 3 is an elastomer film, it may be a rubber-like elastic film having a rubber hardness exceeding 80 (the upper limit is, for example, 100). In this specification, the rubber hardness means the hardness evaluated by a type A durometer defined in JIS K6253:2006.

[0029] The waterproof film 3 may be a porous film. The PTFE film may be a porous film (PTFE porous film) formed by stretching a paste extrudate or a cast film containing PTFE particles. The PTFE film may be fired.

[0030] When it is assumed that the electronic device with the conversion element member 1 attached is exposed to a higher water pressure, the waterproof film 3 is preferably a microporous film or a non-porous film. The microporous film and the non-porous film can have high water pressure resistance and a small degree of deformation due to water pressure. The microporous film may be a PTFE microporous film made of PTFE. The non-porous film may be a PTFE non-porous film made of PTFE.

[0031] In this specification, the microporous membrane means a membrane having an air permeability in the thickness direction, represented by the air permeability (Gurley air permeability) determined in accordance with the air permeability measurement B method (Gurley method) defined in Japanese Industrial Standards (hereinafter referred to as "JIS") L1096:2010, of 10 seconds / 100 mL or more and 10,000 seconds / 100 mL or less. The lower limit of the Gurley air permeability in the microporous membrane may be 20 seconds / 100 mL or more, 30 seconds / 100 mL or more, 40 seconds / 100 mL or more, 50 seconds / 100 mL or more, or even 70 seconds / 100 mL or more. The upper limit of the Gurley air permeability in the microporous membrane may be 5,000 seconds / 100 mL or less, 1,000 seconds / 100 mL or less, or even 300 seconds / 100 mL or less. In this specification, the non-porous membrane means a membrane having an air permeability in the thickness direction, represented by the above Gurley air permeability, exceeding 10,000 seconds / 100 mL. The air permeability in the thickness direction of the porous membrane is usually less than 10 seconds / 100 mL, represented by the above Gurley air permeability.

[0032] In addition, even when the size of the waterproof membrane 3 is less than the size of the test piece (about 50 mm × 50 mm) in the Gurley method, the Gurley air permeability can be evaluated by using a measuring jig. An example of the measuring jig is a polycarbonate disk having a thickness of 2 mm and a diameter of 47 mm with a through-hole (having a circular cross-section with a diameter of 1 mm or 2 mm) provided at the center. The measurement of the Gurley air permeability using this measuring jig can be carried out as follows.

[0033] Fix a waterproof film to be evaluated on one surface of the measuring jig so as to cover the opening of the through-hole of the measuring jig. The fixing is performed such that only the opening and the effective test part of the waterproof film to be evaluated (the part overlapping the opening when viewed from a direction perpendicular to the main surface of the fixed waterproof film) allow air to pass through during the measurement of Gurley air permeability, and the fixing part does not inhibit the passage of air in the effective test part of the waterproof film. For fixing the waterproof film, a double-sided adhesive tape with a vent hole having a shape matching the shape of the opening punched in the center can be used. The double-sided adhesive tape may be disposed between the measuring jig and the waterproof film so that the periphery of the vent hole coincides with the periphery of the opening. Next, set the measuring jig with the waterproof film fixed to a Gurley-type air permeability tester so that the fixed surface of the waterproof film is on the downstream side of the air flow during measurement, and measure the time t1 for 100 mL of air to pass through the waterproof film. Next, divide the measured time t1 by the value t per effective test area of 642 [mm 2 according to the formula t = {(t1)×(area of the effective test part of the waterproof film [mm 2 ) / 642 [mm 2}, and the obtained converted value t can be used as the Gurley air permeability of the waterproof film. When using the above disc as the measuring jig, the area of the effective test part of the waterproof film is the cross-sectional area of the through-hole. It should be noted that it has been confirmed that the Gurley air permeability measured without using a measuring jig for a waterproof film satisfying the size of the test piece and the Gurley air permeability measured using a measuring jig after fragmenting the waterproof film match well, that is, the use of the measuring jig does not substantially affect the measured value of the Gurley air permeability.

[0034] When the temperature of the housing decreases due to the use or attachment of an electronic device in water, etc., condensation may occur inside the housing. The occurrence of condensation can be prevented by reducing the amount of water vapor remaining inside the housing. When the waterproof film 3 is a non-porous film, for example, a PTFE non-porous film, the intrusion of water vapor into the housing through the waterproof film 3 is blocked. Therefore, by selecting a non-porous film as the waterproof film 3, the amount of water vapor remaining inside the housing can be reduced, and the occurrence of condensation inside the housing can be prevented.

[0035] On the other hand, even if there is no intrusion of water vapor into the inside of the housing through the waterproof film 3, the retention of water vapor inside the housing may be inevitable. For example, this is the case when the housing is made of a hygroscopic resin such as polybutylene terephthalate (PBT), acrylonitrile-butadiene-styrene resin (ABS), polymethyl methacrylate (PMMA), polypropylene (PP), or polycarbonate (PC). In a housing made of a hygroscopic resin, the external water vapor absorbed by the housing itself is released into the inside of the housing by the heat from the heat source inside the housing and tends to remain as it is. In this case, in order to prevent the occurrence of dew condensation inside the housing, it is preferable to select a waterproof film 3 that can release the water vapor retained inside the housing to the outside. An example of the selectable waterproof film 3 is a microporous film, for example, a PTFE microporous film. When the waterproof film 3 is a microporous film, while achieving high waterproofness, it is possible to discharge the retained water vapor to the outside by the appropriate air permeability of the waterproof film 3, and the occurrence of dew condensation inside the housing can be prevented.

[0036] The average pore diameter of the waterproof film 3 which is a PTFE microporous film is, for example, 0.01 to 1 μm. The porosity of the waterproof film 3 which is a PTFE microporous film is, for example, 5 to 50%. The average pore diameter of the PTFE film can be measured in accordance with ASTM (American Society for Testing and Materials) F316-86. The porosity of the PTFE film can be calculated by substituting the mass, thickness, area (area of the main surface), and true density of the film into the following formula. The true density of PTFE is 2.18 g / cm 3 is. Porosity (%) = {1 - (mass [g] / (thickness [cm] × area [cm 2 × true density [2.18 g / cm 3 ))} × 100

[0037] The thickness of the waterproof film 3 is, for example, 1 to 50 μm, and may be 3 to 30 μm, or even 5 to 20 μm. When the thickness is within these ranges, the waterproofness and characteristics such as sound transmission characteristics of the waterproof film 3 can be improved in a well-balanced manner.

[0038] The areal density of the waterproof film 3 is, for example, 1 to 30 g / m 2 and is 1 to 25 g / m2 It may be. The areal density can be calculated by dividing the mass of the waterproof film 3 by the area (the area of the main surface).

[0039] The waterproof property of the waterproof film 3 can be evaluated by the water pressure resistance (the ultimate water pressure resistance). The water pressure resistance of the waterproof film 3 is, for example, 15 kPa or more. The water pressure resistance of the porous film waterproof film 3 may be 30 kPa or more, 40 kPa or more, 50 kPa or more, and even 100 kPa or more. The upper limit of the water pressure resistance of the porous film waterproof film 3 is, for example, 300 kPa or less. The water pressure resistance of the microporous film waterproof film 3 may be 100 kPa or more, 200 kPa or more, 300 kPa or more, and even 400 kPa or more. The upper limit of the water pressure resistance of the microporous film waterproof film 3 is, for example, 2500 kPa or less. The water pressure resistance of the non-porous film waterproof film 3 may be 400 kPa or more, 700 kPa or more, 1100 kPa or more, and even 1500 kPa or more. The upper limit of the water pressure resistance of the non-porous film waterproof film 3 is not limited, for example, 2500 kPa or less. The water pressure resistance of the waterproof film 3 can be measured as follows using a measuring jig and in accordance with Test Method A (low water pressure method) or Test Method B (high water pressure method) of Water Resistance Degree in JIS L1092:2009.

[0040] An example of the measuring jig is a disk made of metal or resin with a diameter of 47 mm and having a through-hole with a diameter of 1 mm (having a circular cross-section) provided in the center. The metal is, for example, stainless steel. The resin is, for example, polycarbonate. This disk has a thickness that does not deform under the water pressure applied when measuring the water pressure resistance. The measurement of the water pressure resistance using this measuring jig can be carried out as follows.

[0041] Fix a waterproof film to be evaluated on one surface of the measuring jig so as to cover the opening of the through-hole of the measuring jig. The fixing is performed so that water does not leak from the fixed portion of the film during the measurement of the water pressure resistance. For fixing the waterproof film, a double-sided adhesive tape having a water passage hole with a shape matching the shape of the opening punched in the center can be used. The double-sided adhesive tape may be disposed between the measuring jig and the waterproof film so that the circumference of the water passage hole coincides with the circumference of the opening. Next, set the measuring jig with the waterproof film fixed to the test device so that the surface opposite to the fixed surface of the waterproof film becomes the water pressure application surface during measurement, and measure the water pressure resistance according to Test Method A (low water pressure method) or Test Method B (high water pressure method) of the water resistance test in JIS L1092:2009. However, the water pressure resistance is measured based on the water pressure when water comes out from one location on the film surface of the waterproof film. The measured water pressure resistance can be taken as the water pressure resistance of the waterproof film. As the test device, a device having the same configuration as the water resistance test device exemplified in JIS L1092:2009 and having a test piece mounting structure capable of setting the above-mentioned measuring jig can be used.

[0042] In the examples shown in FIGS. 1A and 1B, the waterproof film 3 is a single-layer film. The waterproof film 3 may be a laminate of two or more films. The waterproof film 3 may be a laminate of two or more PTFE films.

[0043] The waterproof film 3 may be a colored film. The waterproof film 3 may be colored, for example, gray or black. The gray or black waterproof film 3 can be formed, for example, by mixing a gray or black colorant into the material constituting the film. The black colorant is, for example, carbon black. Note that a color in the range of 1 to 4 represented by the "achromatic lightness NV" defined in JIS Z8721:1993 can be defined as "black", and a color in the range of 5 to 8 can be defined as "gray", respectively.

[0044] In the example shown in FIGS. 1A and 1B, the conversion element 2 included in the conversion element member 1 is an acoustic conversion element, and more specifically, a microphone. However, the acoustic conversion element that the conversion element member 1 can include is not limited to a microphone. The acoustic conversion element may be a speaker. However, according to the study by the present inventors, when the acoustic conversion element is a microphone, the deterioration of the sound transmission characteristics due to the permanent deformation of the waterproof film 3 and the deterioration of the sound transmission characteristics when the area of the non-bonded portion 31 of the waterproof film 3 is reduced are more significant than when the acoustic conversion element is a speaker. Therefore, when the acoustic conversion element is a microphone, the effect according to the present invention is particularly advantageous. In addition, when the acoustic conversion element is an element having both functions of a microphone and a speaker, the element is assumed to be a microphone.

[0045] The acoustic conversion element in the example shown in FIGS. 1A and 1B is a MEMS. However, the acoustic conversion element is not limited to this example, and various elements other than MEMS, such as an electret condenser microphone (ECM), may be used.

[0046] An example of the MEMS microphone 2A is shown in Fig. 4. The MEMS microphone 2A in Fig. 4 includes a substrate 21 and a cap 24 joined to a peripheral portion on one surface of the substrate 21. The substrate 21 is, for example, a semiconductor substrate made of silicon (Si), a compound semiconductor, or the like. The cap 24 is made of, for example, metal, resin, or a composite material thereof. An opening 22, which is a sound passage opening, is formed on the outer surface of the substrate 21. Near the opening 22 in the space 26 between the substrate 21 and the cap 24, a diaphragm 25 that converts the sound transmitted through the opening 22 into mechanical vibration is disposed. The diaphragm 25 is made of, for example, resin. The diaphragm 25 is supported by a pair of struts 29A and 29B extending from the above-mentioned one surface of the substrate 21 toward the space 26. Inside the struts 29A and 29B, a semiconductor circuit that converts the mechanical vibration of the diaphragm 25 into an electrical signal is formed. The mechanical vibration generated in the diaphragm 25 by the transmission of sound is transmitted to the struts 29A and 29B and converted into an electrical signal, and the converted electrical signal is output to the outside of the MEMS microphone 2A through an electrical path including a connector 27A, a preamplifier 28, a via electrode 27B, and a terminal 27C.

[0047] The MEMS microphone 2A shown in Fig. 4 is a so-called "bottom sound hole type" element in which the opening 22 and the terminal 27C are formed on the same surface of the element (in the example of Fig. 4, the outer surface 23 of the substrate 21). The MEMS microphone 2A may be a so-called "top sound hole type" element in which the opening 22 and the terminal 27C are disposed on one surface of the element and the other surface opposite to the one surface, respectively. An example of the MEMS microphone 2B of the top sound hole type is shown in Fig. 5. The MEMS microphone 2B in Fig. 5 has the same configuration as the MEMS microphone 2A in Fig. 4 except that the opening 22 is formed in the cap 24 instead of the substrate 21. In the MEMS microphone 2B of Fig. 5, the exposed surface to the outside of the cap 24 is the above-mentioned outer surface 23.

[0048] The MEMS microphones 2A and 2B can be formed by known MEMS technologies constituted by semiconductor processing technologies, thin film formation technologies, and the like.

[0049] The configuration of the acoustic conversion element that the conversion element member 1 can include is not limited to the above example. The acoustic conversion element can have any configuration as long as it has the outer surface 23 in which the opening 22 is formed. Also, known elements can be used for the acoustic conversion element.

[0050] In the examples shown in FIGS. 1A and 1B, the shape of the opening of the opening 22 as viewed from the direction perpendicular to the outer surface 23 is a circle. However, the shape of the opening of the opening 22 is not limited to this example, and may be a circle (including a substantially circle), an ellipse (including a substantially ellipse), a polygon including a square and a rectangle, and an irregular shape as viewed from the direction perpendicular to the outer surface 23.

[0051] The area of the opening 22 when viewed from the direction perpendicular to the outer surface 23 is, for example, 12.6 mm 2 or less, 7.1 mm 2 or less, 4.9 mm 2 or less, 3.1 mm 2 or less, and further may be 1.8 mm 2 or less. When the shape of the opening 22 is a circle as viewed from the direction perpendicular to the outer surface 23, the above area corresponds to the areas of the openings 22 having diameters of 4 mm, 3 mm, 2.5 mm, 2 mm, and 1.5 mm, respectively. When the area of the opening 22 is small, for example, since the degree to which the waterproof film 3 is pushed into the opening 22 by water pressure is suppressed, the effects of the present invention are more reliable.

[0052] The area of the opening 22 when viewed from the direction perpendicular to the outer surface 23 is usually smaller than the area of the non-bonded portion 31 of the waterproof film 3.

[0053] The conversion element member 1 including an acoustic conversion element as the conversion element 2 can have good sound transmission characteristics. In the conversion element member 1, the insertion loss caused by the waterproof film 3 for a sound with a frequency of 1 kHz (hereinafter, the "insertion loss caused by the waterproof film 3" is simply referred to as "insertion loss") is, for example, 4.0 dB or less, and may be 3.0 dB or less, 2.5 dB or less, 2.0 dB or less, 1.5 dB or less, or even 1.0 dB or less. Also, the insertion loss for a sound with a frequency of 10 kHz may be, for example, 4.0 dB or less, and may be 3.0 dB or less, 2.5 dB or less, 2.0 dB or less, 1.5 dB or less, or even 1.0 dB or less. At this time, the waterproof film 3 is typically a porous film. The insertion loss can be evaluated by using the acoustic conversion element included in the conversion element member 1 as an evaluation microphone or speaker.

[0054] The conversion element member 1 including an acoustic conversion element as the conversion element 2 can have good sound transmission characteristics even after a water pressure is applied. In the conversion element member 1, the insertion loss for a sound with a frequency of 1 kHz after a water pressure holding test with a water pressure of 60 kPa or 80 kPa and a water pressure application time of 20 minutes is, for example, 4.0 dB or less, and may be 3.0 dB or less, 2.5 dB or less, 2.0 dB or less, 1.5 dB or less, or even 1.0 dB or less. Also, the insertion loss for a sound with a frequency of 10 kHz after a water pressure holding test with a water pressure of 60 kPa or 80 kPa and a water pressure application time of 20 minutes is, for example, 4.0 dB or less, and may be 3.0 dB or less, 2.5 dB or less, 2.0 dB or less, 1.5 dB or less, or even 1.0 dB or less. At this time, the waterproof film 3 is typically a porous film.

[0055] The hydrostatic pressure retention test is a test in which a constant hydrostatic pressure is applied to the conversion element member 1 over a certain period of time (hydrostatic pressure application time). The hydrostatic pressure retention test can be carried out using the above-described measuring jig and the water resistance test apparatus for measuring the water resistance of the waterproof film 3. More specifically, a measuring jig in which the conversion element member 1 to be evaluated is fixed instead of the single waterproof film 3 is set in the test apparatus such that the surface on the side opposite to the surface on which the conversion element member 1 is fixed becomes the hydrostatic pressure application surface, and a constant hydrostatic pressure may be applied to the conversion element member 1 over a certain period of time. However, the shape and area of the cross section of the through hole of the measuring jig shall be the same as the shape and area of the non-bonded portion 31 of the waterproof film 3 as viewed from a direction perpendicular to the outer surface 23 of the conversion element member 1. Further, the conversion element member 1 is fixed to the measuring jig such that the non-bonded portion 31 of the waterproof film 3 is exposed in the through hole of the measuring jig and the entire through hole of the measuring jig and the entire non-bonded portion 31 overlap as viewed from a direction perpendicular to the outer surface 23. The hydrostatic pressure during the test is applied to the conversion element member 1 from the side of the waterproof film 3.

[0056] Regarding the conversion element member 1 provided with the acoustic conversion element as the conversion element 2, the degree of decrease in the sound transmission characteristics due to the hydrostatic pressure can be evaluated by the degree of decrease in the sound transmission characteristics (insertion loss change amount) obtained from the insertion loss before and after the hydrostatic pressure retention test. The insertion loss change amount corresponds to a value L2 - L1 obtained by subtracting the insertion loss (for example, the insertion loss for a sound of 1 kHz) L1 before the hydrostatic pressure retention test from the insertion loss (for example, the insertion loss for a sound of 1 kHz) L2 after the hydrostatic pressure retention test.

[0057] The change amount of the insertion loss (calculated based on the insertion loss at 1 kHz) before and after the hydrostatic pressure retention test (hydrostatic pressure of 60 kPa or 80 kPa, hydrostatic pressure application time of 20 minutes) is, for example, 2.0 dB or less, and may be 1.5 dB or less, 1.3 dB or less, 1.2 dB or less, 1.1 dB or less, and further 1.0 dB or less. Also, the change amount of the insertion loss (calculated based on the insertion loss at 10 kHz) before and after the hydrostatic pressure retention test (hydrostatic pressure of 60 kPa or 80 kPa, hydrostatic pressure application time of 20 minutes) is, for example, 5.0 dB or less, and may be 4.5 dB or less, 4.0 dB or less, 3.5 dB or less, 3.0 dB or less, 2.5 dB or less, 2.0 dB or less, 1.5 dB or less, and further 1.0 dB or less.

[0058] The conversion element member 1 provided with an acoustic conversion element as the conversion element 2 can have good sound conduction characteristics even when the area of the non-bonded portion 31 of the waterproof film 3 is reduced. Note that the insertion loss usually increases as the area of the non-bonded portion 31 becomes smaller. The conversion element member 1 can exhibit the insertion loss and / or the amount of change in insertion loss within the above-described range when the area of the non-bonded portion 31 of the waterproof film 3 is 19.6 mm 2 , 12.6 mm 2 , 7.1 mm 2 , 4.9 mm 2 , 3.1 mm 2 , or 1.8 mm 2 . Also, the conversion element member 1 can exhibit the insertion loss and / or the amount of change in insertion loss within the above-described range when the area of the non-bonded portion 31 of the waterproof film 3 is 19.6 mm 2 or more, 12.6 mm 2 or more, 7.1 mm 2 or more, 4.9 mm 2 or more, 3.1 mm 2 or more, or 1.8 mm 2 or more.

[0059] The water pressure resistance of the conversion element member 1 is usually the same as the water pressure resistance of the waterproof film 3 when the conversion element member 1 does not have a configuration for increasing the water pressure resistance as the conversion element member 1. Note that the water pressure resistance of the conversion element member 1 can be measured according to the above-described method for measuring the water pressure resistance of the waterproof film 3. However, a measuring jig with the conversion element member 1 to be evaluated fixed instead of the single waterproof film 3 is set in the test apparatus so that the surface on the side opposite to the fixed surface of the conversion element member 1 becomes the water pressure application surface. Also, the fixing of the conversion element member 1 to the measuring jig is performed so that the non-bonded portion 31 of the waterproof film 3 is exposed to the through-hole of the measuring jig. The water pressure during measurement is applied to the conversion element member 1 from the side of the waterproof film 3.

[0060] The conversion element member 1 can be housed and used, for example, in a housing of an electronic device including a housing that houses a voice conversion unit that converts an electrical signal and sound, and is provided with an external circulation port that transmits sound between the voice conversion unit and the outside. An example of the state of housing the conversion element member 1 with respect to the housing of the electronic device is shown in FIGS. 6A and 6B. In the example shown in FIGS. 6A and 6B, the conversion element member 1 is configured such that sound can be transmitted between the outside of the housing 53 and the conversion element 2 through the opening 22 of the conversion element member 1 and the external circulation port 54 of the housing 53, and water intrusion from the outside of the housing 53 to the opening 22 through the external circulation port is prevented by the waterproof film 3. More specifically, the conversion element member 1 is housed inside the housing 53 as shown below.

[0061] The conversion element member 1 is fixed to the circuit board 51. The circuit board 51 is provided with a circulation port 52 which is a sound passage port. With the adhesive part 4 and the waterproof film 3 inserted inside the circulation port 52, the conversion element member 1 is fixed to the circuit board 51. In the examples shown in FIGS. 6A and 6B, with the state of being fixed to the circuit board 51, sound transmission through the opening 22, the waterproof film 3, and the circulation port 52 of the circuit board 51 is possible. Also, in the examples shown in FIGS. 6A and 6B, when viewed from a direction perpendicular to the main surface of the circuit board 51, the shapes and areas of the opening 22 and the external circulation port 54 are the same, and the opening 22 and the external circulation port 54 overlap. The whole of the opening 22 and the whole of the external circulation port 54 may overlap. When viewed from a direction perpendicular to the main surface of the circuit board 51, the area of the circulation port 52 is larger than the areas of the opening 22 and the external circulation port 54, and the opening 22 and the external circulation port 54 overlap with the circulation port 52. Also, a seal 5 is provided on the surface of the waterproof film 3 on the side opposite to the conversion element 2 side. The seal 5 prevents foreign substances such as water from entering the inside of the housing 53 from the gap between the circuit board 51 and the housing 53. The seal 5 is in contact with the inner surface of the housing 53. In the example shown in FIG. 6A, when viewed from a direction perpendicular to the main surface of the waterproof film 3, the seal 5 has the shape of the peripheral edge portion of the waterproof film 3. Also, in this example, when viewed from a direction perpendicular to the main surface of the waterproof film 3, the shape and area of the seal 5 are the same as those of the joint part 41 and the adhesive part 4. On the other hand, in the example shown in FIG. 6B, when viewed from a direction perpendicular to the main surface of the waterproof film 3, the seal 5 has a shape surrounding the external circulation port 54, and the inner circumference of the seal 5 coincides with the circumference of the external circulation port 54. Also, in this example, when viewed from a direction perpendicular to the main surface of the waterproof film 3, the area of the seal 5 is larger than that of the joint part 41 and the adhesive part 4. Terminals electrically connectable to the terminal 27C of the conversion element member 1 are provided on the fixing surface of the conversion element member 1 on the circuit board 51. In the state of being fixed to the circuit board 51, electrical signals can be exchanged between the conversion element member 1 and the circuit board 51 via the respective terminals. The configuration of the circuit board 51 is not limited as long as electrical signal exchange with the conversion element member 1 is possible. Also, the method of fixing (mounting) the conversion element member 1 to the circuit board 51 is not limited to the methods shown in FIGS. 6A and 6B.

[0062] The circuit board 51 on which the conversion element member 1 is mounted is housed inside the housing 53 such that sound can be transmitted between the conversion element member 1 and the outside of the housing 53 via the opening 22, the circulation port 52, and the external circulation port 54, and water intrusion from the outside of the housing 53 into the opening 22 via the external circulation port 54 is blocked by the waterproof film 3.

[0063] The waterproof property of the waterproof film is easier to ensure as the area of the non-bonded portion is smaller. For this reason, conventionally, the form shown in FIG. 7 has usually been adopted. In the form shown in FIG. 7, the shape of the adhesive portion 104 has a shape surrounding the opening 22 when viewed from a direction perpendicular to the main surface of the waterproof film 103, and the inner periphery of the adhesive portion 104 coincides with the shape of the opening 22. Also, the shape of the seal 105 has a shape surrounding the external circulation port 54 when viewed from a direction perpendicular to the main surface of the circuit board 51, and the inner periphery of the seal 105 coincides with the periphery of the external circulation port 54. In the state shown in FIG. 7, the region corresponding to the above region 32 does not exist in the waterproof film 103. In the state shown in FIG. 7, by making the shape of the non-bonded portion of the waterproof film 103 coincide with the shapes of the opening 22 and the external circulation port 54, improvement in the waterproof property of the waterproof film 103 alone is achieved by reducing the area of this portion. Also, in the form shown in FIG. 7, the waterproof film 103 is usually handled as a laminate with the adhesive portion 104 and the seal 105, and the waterproof film 103 is disposed between the substrate 21 and the housing 53 as this laminate. At this time, the area of the waterproof film 103 is made as small as possible within the range that can cover the opening 22 and the external circulation port 54 to increase the rigidity of the laminate during handling, thereby suppressing unintended distortion and deformation of the waterproof film 103 during placement and improving the waterproof property and characteristics of the waterproof film 3 alone. Also, regarding the opening 52 of the circuit board 51, from the viewpoint of waterproof property, it has the minimum area capable of accommodating the above laminate.

[0064] The seal 5 can have the configuration described above in the description of the adhesive portion 4. However, the seal 5 may or may not have adhesiveness. The seal 5 may be composed of a resin elastic body such as a foam, for example. In this case, for example, in the examples shown in FIGS. 6A and 6B, by setting the total thickness of the adhesive portion 4, the waterproof film 3, and the seal 5 to be larger than the thickness of the circuit board 51 (the depth of the circulation port 52), it becomes possible to fix the conversion element member 1 to the circuit board 51 in a state where the seal 5 is compressed in the thickness direction, and the sealing characteristics of the seal 5 can be enhanced. Note that the fixing of the conversion element member 1 to the circuit board 51 in a state where the seal 5 is compressed in the thickness direction can be realized not only in the examples shown in FIGS. 6A and 6B.

[0065] The state of accommodation of the conversion element member 1 including the acoustic conversion element with respect to the housing 53 of the electronic device is not limited to the examples shown in FIGS. 6A and 6B as long as sound can be transmitted between the outside of the housing 53 and the conversion element 2 through the opening 22 and the external circulation port 54, and the waterproof film 3 prevents water from entering the inside of the housing 53 and the conversion element 2. Further, the conversion element member 1 can be accommodated inside the housing 53 using any member as long as the above-described sound transmission and water intrusion prevention are possible.

[0066] The conversion element member of the present invention may be in a state where the seal 5 is disposed on the surface of the waterproof film 3 opposite to the side of the conversion element 2, and it can also be circulated in this state. An example of the conversion element member 1 with the seal 5 disposed thereon is shown in FIG. 8. FIG. 8 shows the vicinity of the waterproof film 3 and the opening 22 in this example. Further, a separator 6 for protecting the non-bonded portion 31 of the seal 5 and the waterproof film 3 may be further disposed, and the conversion element member 1 can also be circulated in this state. An example of the conversion element member 1 with the seal 5 and the separator 6 disposed thereon is shown in FIG. 9. FIG. 9 shows the vicinity of the waterproof film 3 and the opening 22 in this example. As the separator 6, a known separator made of paper, resin, metal, or a composite material thereof, for example, a separator used for an adhesive tape, can be used. The separator 6 may have adhesiveness on the surface in contact with the seal 5. When the conversion element member 1 is used, the separator 6 is peeled off.

[0067] The conversion element member 1 can include any member other than those described above as long as the effects of the present invention can be obtained.

[0068] The conversion element member 1 can be formed by disposing and joining the waterproof film 3 at the joint portion 41 having a shape that closes the opening 22 and surrounds the opening 22 as viewed from a direction perpendicular to the outer surface 23 on which the opening 22 is formed in the conversion element 2. However, the waterproof film 3 is disposed and joined so that the non-bonded portion 31 of the waterproof film 3 has a region 32 that overlaps the outer surface 23 as viewed from the above direction.

[0069] [Conversion element module] The conversion element member 1 can be circulated and used as a conversion element module 7 including the circuit board 51 in a state where it is mounted on the circuit board 51, that is, in other words, including the conversion element member 1 and the circuit board 51 on which the conversion element member 1 is mounted.

[0070] The conversion element member 1 included in the conversion element module 7 is the conversion element member of the present invention, for example, the conversion element member 1 shown in each of the above-described examples. However, the conversion element member 1 included in the conversion element module 7 is not limited to those shown in each of the above-described examples as long as it is the conversion element member of the present invention.

[0071] The circuit board 51 included in the conversion element module 7 is not limited as long as it can exchange electrical signals with the conversion element member 1 mounted on the circuit board 51. The circuit board 51 may be a circuit board on which a minimum electronic circuit for receiving and transmitting electrical signals from and / or to the conversion element member 1, typically, electrical signals output from the conversion element 2 included in the conversion element member 1 and / or electrical signals input to the conversion element 2, is formed, or may be a circuit board further including various electronic circuits and / or elements capable of executing various processes on the electrical signals. An example of the conversion element module 7 is shown in FIGS. 10A and 10B. FIG. 10B is a plan view of the conversion element module 7 shown in FIG. 10A as viewed from the side opposite to the surface of the circuit board 51 on which the conversion element member 1 is mounted. As shown in FIG. 10B, a flow port 52 can be confirmed on the opposite surface of the circuit board 51. Reference numeral 57 in FIG. 10A is a terminal, and reference numeral 58 is an element such as a resistance element or a diode element.

[0072] Examples of mounting the conversion element member 1 on the circuit board 51 are shown in FIGS. 6A and 6B. As shown in FIGS. 6A and 6B, the circuit board 51 has a flow port 52 capable of transmitting sound to and from the opening 22 of the conversion element 2, and the conversion element member 1 may be fixed to the circuit board 51 with the waterproof film 3 inserted inside the flow port 52. However, the mounting mode of the conversion element member 1 on the circuit board 51 is not limited to the above example.

[0073] [Electronic device] FIG. 11 shows an example of an electronic device in which the conversion element member 1 is used. The electronic device shown in FIG. 11 is a smartphone 60. Inside the housing 53 of the smartphone 60, an audio conversion unit that converts an electrical signal and sound is disposed. The audio conversion unit includes a conversion element 2 which is an acoustic conversion element having the function of a speaker and / or a microphone. The conversion element 2 may be a microphone. The housing 53 is provided with openings 54A and 54B which are external circulation ports.

[0074] The audio conversion unit in the smartphone 60 includes the conversion element 2 as the conversion element member 1 and / or the conversion element module 7. In the smartphone 60, the conversion element member 1 and / or the conversion element module 7 are housed inside the housing 53 such that sound can be transmitted between the opening 22 of the conversion element 2 and the outside of the housing 53 through the external circulation port 54 of the housing 53, and water intrusion from the outside to the opening 22 through the external circulation port 54 is blocked by the waterproof film 3. Examples of the state in which the conversion element member 1 or the conversion element module 7 is housed inside the housing 53 are shown in FIGS. 6A and 6B.

[0075] When the waterproof film 3 has air permeability in the thickness direction, the conversion element 2 may be, for example, a characteristic conversion element that converts the characteristics of a gas and an electrical signal. The characteristic conversion element has an opening 22 that can function as a vent for transmitting (circulating) a gas. The characteristics of the gas are, for example, pressure, flow rate, concentration of a specific gas species (O 2 etc.). However, the characteristics of the gas are not limited to the above examples. The conversion element member 1 including the characteristic conversion element as the conversion element 2 can be used for an electronic device which is a sensor device such as a pressure sensor, a flow rate sensor, an O 2 concentration sensor, etc. However, the use of the conversion element member 1 is not limited to the above examples.

[0076] When the conversion element 2 is a characteristic conversion element, the waterproof film 3 is required to prevent water intrusion while allowing gas permeation. In this case, the waterproof film 3 may be a porous film. Also, in this case, the portion of the waterproof film 3 through which the gas mainly permeates is the non-bonded portion 31.

[0077] When a water pressure is applied in the direction of the element to the waterproof film 3 of the conversion element member 1 including the characteristic conversion element as the conversion element 2, even when the water pressure applied to the waterproof film 3 is large, or when the water pressure is continuously applied to the waterproof film 3, the deformation of the waterproof film 3 is limited to the range of elastic deformation without reaching plastic deformation. Further, the permanent deformation remaining in the waterproof film 3 even after release from the water pressure reduces the air permeability of the conversion element member 1. For example, variations in ventilation occur, or a deviation from the designed air permeability as the conversion element member 1 occurs. Variations in ventilation and deviations from the designed air permeability may, for example, adversely affect the performance of the device when the electronic device is a sensor device such as a pressure sensor. In the conversion element member 1, by restricting the deformation of the waterproof film 3 due to water pressure within the range of elastic deformation, variations in ventilation and deviations from the designed air permeability caused by the application of the above water pressure can be suppressed.

[0078] The conversion element member 1 including the characteristic conversion element as the conversion element 2 can be housed in the housing 53 such that gas can be transmitted (circulated) through the external circulation port 54 of the housing 53 between the housing 53 of the electronic device and the opening (ventilation port) 22 of the conversion element 2, and such that water intrusion from the outside through the external circulation port 54 to the opening 22 is prevented by the waterproof film 3. Note that the electronic device housing the conversion element member 1 does not necessarily have to have an audio conversion unit. Further, the electronic device housing the conversion element member 1 may be an electronic device such as a smartphone having an audio conversion unit. In this case, the conversion element member 1 can be housed inside the housing 53 so as to prevent water intrusion through the external circulation port 54 not corresponding to the audio conversion unit. The external circulation port 54 not corresponding to the audio conversion unit is, for example, a ventilation port (where sound may physically pass through even if not intended in the design of the electronic device) where the passage of sound is not intended in the design of the electronic device. More specific examples are a pressure measurement port, a flow measurement port, and a concentration measurement port.

[0079] The conversion element 2 that the conversion element member 1 of the present invention can include is not limited to the acoustic conversion element and the characteristic conversion element described above as long as it has an opening that can function as a ventilation port and / or a sound passage port.

[0080] An electronic device including the conversion element member 1 and / or the conversion element module 7 is, for example, a wearable device such as a smartwatch and a wristband; various cameras including an action camera and a security camera; a communication device such as a mobile phone and a smartphone; a virtual reality (VR) device; an augmented reality (AR) device; a sensor device, etc. However, the electronic device is not limited to the above examples.

Example

[0081] Hereinafter, the present invention will be described more specifically by way of examples. The present invention is not limited to the following examples.

[0082] (Preparation of waterproof film) As the waterproof film, the following five types of waterproof films A to E were prepared.

[0083] [Waterproof film A] To 100 parts by weight of PTFE fine powder (manufactured by Daikin Industries, Ltd., Polyflon F-104), 20 parts by weight of a liquid lubricant (n-dodecane, manufactured by Japan Energy Corporation) was uniformly mixed, compressed in a cylinder, and then extruded with a ram extruder to obtain a sheet-shaped molded body extending in the longitudinal direction. This sheet-shaped molded body was passed between metal rolling rolls while containing the liquid lubricant and rolled to a thickness of 0.2 mm. Then, the sheet-shaped molded body was heated to 150°C to remove the liquid lubricant and dried. Then, the sheet-shaped molded body was stretched at 300°C at a magnification of 2.5 times in the longitudinal direction and at 200°C at a magnification of 20 times in the width direction, and then fired at 400°C, which is a temperature above the melting point of PTFE, to obtain a waterproof film A, which is a PTFE porous film with a film thickness of 15 μm and an average pore diameter of 0.32 μm.

[0084] [Waterproof film B] A sheet-shaped molded body with a thickness of 0.2 mm (before removal of the liquid lubricant), obtained in the same manner as when producing the waterproof film A, was stretched at 25°C in the width direction at a magnification of 4.5 times. Next, the stretched sheet-shaped molded body was heated to 150°C to remove the liquid lubricant and dried. Thereafter, the sheet-shaped molded body was stretched at 300°C in the longitudinal direction at a magnification of 2.0 times and in the width direction at a magnification of 20 times at 100°C, and then fired at 400°C, which is a temperature equal to or higher than the melting point of PTFE, to obtain a waterproof film B, which is a PTFE porous film with a film thickness of 6 μm and an average pore diameter of 0.48 μm.

[0085] [Waterproof film C] For the sheet-shaped molded body from which the liquid lubricant had been removed, the stretching temperature in the longitudinal direction was 380°C and the stretching magnification was 4.5 times, and the stretching temperature in the width direction was 330°C and the stretching magnification was 10 times. In addition, except that firing after stretching in the width direction was not carried out, in the same manner as for the waterproof film A, a waterproof film C, which is a PTFE porous film with a film thickness of 25 μm and an average pore diameter of 0.88 μm, was obtained.

[0086] [Waterproof film D] As the waterproof film D, a silicone rubber sheet (thickness: 40 μm, hardness: 65, non-porous film, black) was prepared.

[0087] [Waterproof film E] As the waterproof film E, a polyurethane sheet (thickness: 10 μm, hardness: 95, non-porous film, white) was prepared.

[0088] (Characteristics evaluation of waterproof films A to E) For the above-prepared waterproof films A to E, the following characteristics were evaluated.

[0089] [Air permeability in the thickness direction ( Gurley air permeability)] The air permeability in the thickness direction of the waterproof film was evaluated as the air permeability (Gurley air permeability) by the above-described method in accordance with the air permeability measurement method B (Gurley method) specified in JIS L1096:2010. As a result of the evaluation, the Gurley air permeabilities of the waterproof film A, the waterproof film B, and the waterproof film C were 1.0 second / 100 mL, 2.0 seconds / 100 mL, and 0.2 second / 100 mL, respectively. The Gurley air permeabilities of the waterproof film D and the waterproof film E exceeded 10,000 seconds / 100 mL.

[0090] [Evaluation of the insertion amount X by the insertion test] The penetration amount X of the waterproof film was evaluated by conducting the above-described penetration test. More specifically, the penetration amount X was evaluated as follows (see Fig. 12). First, as a testing machine for the penetration test, a precision universal testing machine (AG-5kNXPlus HS, manufactured by Shimadzu Corporation) capable of pushing a measuring element against the surface of a film-shaped test piece at a constant speed was prepared. Next, the waterproof film to be evaluated was cut out into a circle with a diameter of 5.8 mm to obtain a test piece 81. Next, a double-sided adhesive tape 82 (ring-shaped with an outer diameter of 5.8 mm and an inner diameter of 2.0 mm, thickness 200 μm, No. 57120B manufactured by Nitto Denko Corporation) was bonded to one main surface of the test piece 81, and a double-sided adhesive tape 83 (ring-shaped with an outer diameter of 5.8 mm and an inner diameter of 2.0 mm, thickness 30 μm, No. 5603 manufactured by Nitto Denko Corporation) and a PET sheet 84 (ring-shaped with an outer diameter of 5.8 mm and an inner diameter of 2.0 mm, thickness 0.1 mm, Lumirror manufactured by Toray Industries, Inc.) were bonded to the other main surface of the test piece 81 in this order to obtain a laminate 85. The double-sided adhesive tape 82, the double-sided adhesive tape 83, and the PET sheet 84 were bonded through the adhesive layers of the double-sided adhesive tapes 82 and 83 so that the outer circumferences of the respective members coincided with each other and the outer circumferences of the respective members and the circumference of the test piece 81 coincided. Next, the laminate 85 was placed and fixed on the surface of a polycarbonate plate 86 provided with a through-hole having a diameter of 2.0 mm extending perpendicularly to the surface through the adhesive layer of the double-sided adhesive tape 82. The fixing of the laminate 85 was carried out so that the inner circumference of the double-sided adhesive tape 82 and the circumference of the through-hole of the polycarbonate plate 86 coincided when viewed from a direction perpendicular to the main surface of the test piece 81. Next, the polycarbonate plate 86 and the laminate 85 were fixed to the testing machine with the polycarbonate plate 86 facing downward, and a penetration test was conducted in which a needle (measuring element) 87 was pushed into the test piece 81 from above at a constant speed. The fixing of the polycarbonate plate 86 and the laminate 85 to the testing machine was carried out so that the needle 87 could be pushed vertically downward through the through-holes of the double-sided adhesive tape 83 and the PET sheet 84 with respect to the test piece 81 in the penetration test. As the needle 87, a columnar (diameter 0.8 mm) one with a hemispherical shape with a radius of 0.35 mm at one end pushed into the test piece 81 was used, and the penetration speed of the needle 87 with respect to the test piece 81 was set to 10 mm / min.In addition, the evaluation is carried out in an atmosphere of a temperature of 25 ± 5°C and a relative humidity of 60 ± 10%. For five test pieces 81 cut from different locations of one waterproof film, a push-in test is carried out respectively. For each test piece, the average value of the push-in amount at which the repulsive force generated in the test piece by the push-in of the measuring element becomes the maximum is taken as the push-in amount X. Also, the maximum value of the above repulsive force in each waterproof film to be evaluated is obtained as the average value of the values obtained for the above five test pieces. The evaluation results are shown in Table 1 below.

[0091]

Table 1

[0092] (Characteristic evaluation as a conversion element member) [Relationship between separation distance D1 and sound transmission characteristics (insertion loss)] Using the above-prepared waterproof films A, B, D, E and a separately prepared MEMS microphone (manufactured by Knowles, SPU0410LR5H), the relationship between the separation distance D1 and the sound transmission characteristics (insertion loss) was evaluated. The specific evaluation method is as follows.

[0093] First, a waterproof film was cut out into a circle with a diameter of 5.8 mm. Next, a double-sided adhesive tape A (ring-shaped with an outer diameter of 5.8 mm and an inner diameter of 2.0 mm, thickness 200 μm, No. 57120B manufactured by Nitto Denko Corporation) was bonded to one main surface of the cut-out waterproof film, and a laminate of a double-sided adhesive tape B (ring-shaped with an outer diameter of 5.8 mm and an inner diameter of 2.0 mm, thickness 30 μm, No. 5603 manufactured by Nitto Denko Corporation) and a PET sheet (ring-shaped with an outer diameter of 5.8 mm and an inner diameter of 2.0 mm, thickness 0.1 mm, Lumirror manufactured by Toray Industries, Inc.) was bonded in multiple sets to the other main surface to obtain a sample for evaluation. The bonding of the double-sided adhesive tape A, the double-sided adhesive tape B, and the PET sheet was carried out through the adhesive layers of the double-sided adhesive tapes A and B such that the outer peripheries of the respective members were aligned with each other and the outer peripheries of the respective members and the periphery of the waterproof film were aligned. Also, the bonding of the laminate was carried out such that the double-sided adhesive tape B and the waterproof film were in contact. The laminate of the PET sheet and the double-sided adhesive tape B was used as the adhesive portion 4 and the spacer 42 for adjusting the separation distance D1. When using three sets of the laminate, the separation distance D1 when combined with the MEMS microphone was 0.4 mm, that is, the separation distance D1 was equal to or less than the pushing-in amount X of the waterproof films A and B. When using eight sets of the laminate, the separation distance D1 when combined with the MEMS microphone was 1.0 mm, that is, the separation distance D1 exceeded the pushing-in amount X of the waterproof films A and B. Therefore, according to the above sample, Examples 1 and 2 having a separation distance D1 of 0.4 mm and Comparative Examples 1 and 2 having a separation distance D1 of 1.0 mm when combined with the MEMS microphone can be prepared. Similarly, Examples 3 and 4 and Comparative Examples 3 and 4 were prepared while changing the thickness of the PET sheet as needed. Table 2 below shows the combinations of the waterproof film, the pushing-in amount X, and the separation distance D1 in each example and comparative example.

[0094]

Table 2

[0095] Next, an evaluation jig 93 used for evaluating the insertion loss was prepared (see FIG. 13). The evaluation jig 93 is a resin box provided with a sound passage port (circular with a diameter of 2 mm) 97 on its upper surface. Inside the evaluation jig 93, a filler 94 and a speaker (manufactured by Star Precision, SCG-16A) 95 are accommodated. The speaker 95 is surrounded by the filler 94. However, the filler 94 is provided with a cylindrical sound passage 96 with a diameter of 2 mm extending from its upper surface to the speaker 95, and the sound output from the speaker 95 can be output to the outside of the evaluation jig 93 through the sound passage 96 and the sound passage port 97. The filler 94 is composed of a foamed resin and is accommodated in the evaluation jig 93 for the purpose of preventing the sound output from the speaker 95 from being transmitted to the outside of the evaluation jig 93 through parts other than the sound passage 96 and the sound passage port 97. Next, a polycarbonate spacer 92 having a circular through-hole 98 with a diameter of 2 mm formed at the center was fixed to the upper surface of the prepared evaluation jig 93. The spacer 92 was fixed such that the center of the sound passage port 97 and the center of the through-hole 98 coincided when viewed from a direction perpendicular to the surface of the spacer 92. Also, an adhesive was used for fixing the spacer 92.

[0096] Next, each of the thus-prepared samples 91 was joined to a spacer 92 via an adhesive layer that was not joined to the waterproof film in the double-sided adhesive tape A. The joining of the sample 91 to the spacer 92 was carried out such that the conversion element member 91 covered the through-hole 98 and the center of the through-hole 98 coincided with the center of the waterproof film when viewed from a direction perpendicular to the main surface of the waterproof film. Next, a MEMS microphone 99 was placed on the sample 91, and further, a weight 100 with a mass of 340 g was placed on the MEMS microphone 99. The weight 100 was used to enable evaluation of sound conduction characteristics equivalent to those of the conversion element member in which the sample 91 and the MEMS microphone 99 were joined by bringing the two into close contact. Also, by enabling evaluation of the sound conduction characteristics without joining the sample 91 and the MEMS microphone 99, repeated use of the MEMS microphone 99 during evaluation became possible. The placement of the MEMS microphone 99 was carried out such that the outer surface of the MEMS microphone 99 where the sound conduction port was formed was in contact with the PET sheet of the sample 91 and the center of the waterproof film coincided with the center of the sound conduction port when viewed from a direction perpendicular to the main surface of the waterproof film. The prepared MEMS microphone 99 was of the downward sound hole type, and the shape of the sound conduction port was a circle with a diameter of 1.0 mm when viewed from a direction perpendicular to the above outer surface. Also, the outer surface of the MEMS microphone 99 where the sound conduction port was formed was flat over at least an approximately 7 mm square area centered on the sound conduction port. In a state where the MEMS microphone 99 was placed, a ring-shaped region (outer diameter 2.0 mm and inner diameter 1.0 mm) overlapping with the outer surface when viewed from a direction perpendicular to the outer surface was formed in the non-joined portion of the waterproof film. Also, the distance between the sound output surface of the speaker 95 and the sound conduction port of the MEMS microphone 99 was approximately 21 mm.

[0097] Next, the MEMS microphone 99 and the speaker 95 were connected to an acoustic evaluation device (manufactured by B&K, Multi-analyzer System 3560-B-030). Next, as the evaluation method, the SSR (Solid State Response) mode (test signal 20 Hz to 20 kHz, sweep up) was selected, and the evaluation of the insertion loss due to the sound transmission film for the above combination of the sound transmission film and the MEMS microphone was performed. The insertion loss can be automatically obtained from the test signal input from the acoustic evaluation device to the speaker 95 and the signal received by the MEMS microphone 99. In addition, when evaluating the insertion loss, the value of the insertion loss (blank value) when the waterproof film was removed from the sample 91 was obtained in advance. The insertion loss of the above combination corresponds to the value obtained by subtracting the blank value from the measured value when the waterproof film is provided. It can be judged that the better the sound transmission characteristics are, the smaller the insertion loss is.

[0098] The evaluation results are shown in Table 3 below. Note that "-" in Table 3 means unmeasured.

[0099]

Table 3

[0100] As shown in Table 3, the smaller the separation distance D1 was, the lower the value of the insertion loss for the sound at a frequency of 1 kHz was, that is, the sound transmission characteristics were good. Note that when the insertion loss takes a negative value, it typically means that the waterproof film resonates with the sound at the frequency, and the sound pressure at the frequency has increased compared to the original sound for evaluation generated from the speaker unit. Therefore, when evaluating the relationship between the separation distance D1 and the sound transmission characteristics, when the insertion loss takes a negative value, it can be judged that "the sound transmission characteristics were good at this separation distance D1" regardless of the value.

[0101] [Change in sound transmission characteristics (insertion loss) before and after the water pressure holding test] Next, after performing a water pressure holding test on each of the fabricated samples 91, the insertion loss after the water pressure holding test in combination with the MEMS microphone was evaluated by the method described above in the description of "the relationship between the separation distance D1 and the sound transmission characteristics (insertion loss)". The water pressure holding test was performed as follows.

[0102] After evaluating the sound transmission characteristics before the water pressure holding test, the sample 91 together with the spacer 92 was removed from the evaluation jig 93. Next, a polycarbonate support plate having a circular through-hole (diameter 1.0 mm) simulating the sound transmission port of the MEMS microphone 99 at the center was placed on the surface of the sample 91 opposite to the spacer 92 side, and the outer peripheries of the spacer 92 and the support plate were evenly clamped with a plurality of clips to fix both with the sample 91 sandwiched therebetween. The support plate was arranged so that the center of the waterproof film and the center of the through-hole of the support plate coincided when viewed from a direction perpendicular to the main surface of the waterproof film. Next, the laminate of the spacer 92, the sample 91, and the support plate was set in the above-described water resistance test apparatus, and a water pressure holding test was performed in which a constant water pressure was applied to the waterproof film over a certain period of time. The water pressure was applied from the side of the spacer 92. The water pressure applied to the waterproof film A was 60 kPa, and the water pressure application time was 20 minutes. The water pressure applied to the waterproof films B, D, and E was 80 kPa, and the water pressure application time was 20 minutes.

[0103] The evaluation results are shown in Table 4 below together with the degree of deterioration of the sound transmission characteristics (change in insertion loss), which is the value obtained by subtracting the insertion loss L1 before the water pressure holding test from the insertion loss L2 after the water pressure holding test. Note that "-" in Table 4 indicates unmeasured.

[0104]

Table 4

[0105] As shown in Table 4, compared with the comparative example where the separation distance D1 exceeds the pushing-in amount X of the waterproof film, in the example where the separation distance D1 is equal to or less than the pushing-in amount X of the waterproof film, the degree of deterioration of the sound transmission characteristics before and after the water pressure holding test was greatly improved, and the degree of increase in the insertion loss due to the water pressure holding test was suppressed. Further, the suppression of the increase in the insertion loss was particularly remarkable for the high-frequency sound in the 10 kHz range. Note that although the amount of change in the insertion loss of Comparative Example 3 is smaller than that of Example 3, at the stage before the water pressure holding test, Comparative Example 3 already had a very large insertion loss (particularly at a frequency of 10 kHz).

Industrial Applicability

[0106] The technology of the present invention can be applied to various electronic devices such as wearable devices such as smartwatches; various cameras; communication devices such as mobile phones and smartphones; and sensor devices.

Explanation of Signs

[0107] 1 Conversion element member 2 Conversion element 2A, 2B MEMS microphone 3 Waterproof film 4 Adhesive part 5 Seal 6 Separator 7 Conversion element module 21 Substrate 22 Opening 23 Outer surface 31 Non-bonding part 32 Region 41 Bonding part 42 Spacer 43 Protrusion 51 Circuit board 52 Flow port 53 Housing 54, 54A, 54B External flow port 57 Terminal 58 Element 60 Smartphone D1 Separation distance D2 Distance

Claims

1. A conversion element having an opening that can function as an air vent and / or a sound vent, and a waterproof membrane; The conversion element has an outer surface in which the opening is formed, The waterproof membrane is The opening is closed by a joint portion that is joined to the outer surface of the conversion element and has a shape that surrounds the opening when viewed in a direction perpendicular to the outer surface, and It has an air permeability in the thickness direction of 2.0 seconds / 100 mL or more, as expressed by air permeability measured in accordance with the air permeability measurement method B (Gurley method) specified in JIS L1096:2010, The non-jointed portion of the waterproof membrane is defined as a portion surrounded by the joint when viewed from a direction perpendicular to the outer surface, and has an area overlapping with the outer surface when viewed from the direction perpendicular to the outer surface; A distance D1 between the waterproof membrane and the outer surface in the region is 0.01 mm or more and X mm or less; A distance D2 between the joint portion and the opening in the region when viewed from a direction perpendicular to the outer surface is larger than the separation distance D1, the transducer element is an acoustic transducer element, The insertion loss of the waterproof membrane for a sound having a frequency of 10 kHz is 4.0 dB or less; A conversion element member in which the change in insertion loss due to the waterproof membrane for a sound having a frequency of 10 kHz before and after a water pressure retention test at a water pressure of 80 kPa and a water pressure application time of 20 minutes is 5.0 dB or less. Here, X is the amount of pressing of the probe at which the repulsive force generated in the waterproof membrane by pressing the probe is maximized when a pressing test of the probe into the waterproof membrane is carried out in accordance with the provisions of the puncture strength test defined in JIS Z1707:1997.

2. 2. The conversion element member according to claim 1, wherein the separation distance D1 is equal to or less than the smaller value selected from the group consisting of X mm and 2 mm.

3. 3. The conversion element member according to claim 1, wherein the separation distance D1 is equal to or smaller than 0.6 times X mm.

4. 4. The conversion element member according to claim 1, wherein a distance D2 between the joint and the opening in the region when viewed from a direction perpendicular to the outer surface is 0.5 mm or more.

5. The area of ​​the opening of the conversion element when viewed in a direction perpendicular to the outer surface is 1.8 mm 2 The conversion element member according to any one of claims 1 to 4, wherein:

6. 6. The conversion element member according to claim 1, wherein the waterproof film includes a polytetrafluoroethylene film.

7. The conversion element member according to any one of claims 1 to 6, wherein the conversion element is a micro-electromechanical system (MEMS).

8. The conversion element member according to any one of claims 1 to 7, wherein the insertion loss of the waterproof membrane for a sound having a frequency of 1 kHz after a water pressure holding test at a water pressure of 60 kPa or 80 kPa and a water pressure application time of 20 minutes is 3.0 dB or less.

9. The conversion element member according to any one of claims 1 to 8, wherein the insertion loss of the waterproof membrane for a sound having a frequency of 10 kHz after a water pressure holding test at a water pressure of 60 kPa or 80 kPa and a water pressure application time of 20 minutes is 3.0 dB or less.

10. A conversion element member according to any one of claims 1 to 9, wherein the change in insertion loss due to the waterproof membrane for a sound having a frequency of 1 kHz before and after a water pressure retention test at a water pressure of 60 kPa or 80 kPa and a water pressure application time of 20 minutes is 2.0 dB or less.

11. A conversion element member according to any one of claims 1 to 10, a circuit board on which the conversion element member is mounted.

12. the circuit board has a flow port capable of transmitting sound and / or gas between the circuit board and the opening of the conversion element, The conversion element module according to claim 11 , wherein the conversion element member is fixed to the circuit board with the waterproof film inserted inside the flow port.

13. A housing provided with an external circulation port through which gas and / or sound can pass; The conversion element member according to any one of claims 1 to 10, which is housed in the housing; The conversion element member is accommodated in the housing such that the waterproof membrane prevents water from entering the opening from outside the housing through the external circulation port.

14. The electronic device includes a sound conversion unit that converts between an electric signal and sound, the sound conversion unit includes the conversion element member having an acoustic conversion element as the conversion element, The electronic device according to claim 13 , wherein the conversion element member is accommodated in the housing so as to enable transmission of sound between the outside and the opening via the external circulation port.

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