JP2005311917A - Capacitor microphone and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein many man-hours for manufacturing is required and the reduction of costs is difficult with respect to a capacitor microphone configured by housing a conventional circuit board, a back electrode substrate formed with an electret layer on a back electrode and a vibrating diaphragm unit fixing a vibrating diaphragm on a supporting frame in a case while stacking them, and by covering acoustic holes of the case with a dust-proof film. <P>SOLUTION: Each of elements such as a circuit board, a back electrode substrate and a vibrating diaphragm unit is comprised of an aggregate substrate and in a step for stacking the aggregate substrates, a dust-proof film is also simultaneously stacked to mass-produce a microphone capsule with a dust-proof film. The microphone capsule with the dust-proof film is then housed in a shield case, thereby eliminating a conventional dust-proof film covering step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention accommodates a microphone capsule in which a circuit board on which electronic components are mounted, a back electrode board in which an electret layer is formed on the back electrode, and a diaphragm unit in which a diaphragm is fixed to a support frame. The present invention relates to a condenser microphone in which the acoustic hole of the case is covered with a dust-proof film, and more particularly to a manufacturing method considering mass productivity.

  In recent years, electret condenser microphones (hereinafter abbreviated as condenser microphones) have been widely used as small and high-performance mycophones, and cost reductions due to mass production of condenser microphones are being studied.

  Hereinafter, the configuration and manufacturing method of a conventional condenser microphone will be described with reference to FIGS. 7 is a sectional view of a conventional completed condenser microphone, FIG. 8 is an exploded perspective view of each element constituting the condenser microphone of FIG. 7, and FIG. 9 is a perspective view showing an intermediate assembled state of the condenser microphone.

  In FIG. 8, reference numeral 2 denotes a circuit board. The circuit board 2 is composed of an insulating substrate 2a, and an electrode 2b for connection and output is formed as a film, and an integrated circuit 11 which is an electronic component is mounted thereon. 3 is a back electrode substrate, the back electrode substrate 3 is formed with a back electrode 4 made of an electrode film on the top surface side of the insulating substrate 3a, and an electret layer 5 is formed on the top surface of the back electrode 4, A through hole 15 penetrating the insulating substrate 3 a is formed outside the back electrode 4 and the electret layer 5.

  The upper surface of the back electrode substrate 3 has a rectangular shape, the back electrode 4 and the electret layer 5 are formed in a circular shape on the upper surface of the back electrode substrate 3, and the through-hole 15 is formed in the back electrode 15. By forming the electrode 4 at a position corresponding to the corner portion of the back electrode substrate 3 outside the formation region of the electrode 4, the area of the upper surface of the back electrode substrate 3 is efficiently used. Reference numeral 6 denotes a spacer.

  Reference numeral 7 denotes a diaphragm unit. The diaphragm unit 7 is integrated by attaching a conductive diaphragm 10 to a diaphragm attachment electrode 9 formed on the lower surface side of a diaphragm support frame 8 made of an insulating substrate. It has become. Reference numeral 16 is a metal shield case, and 17 is a dustproof film.

  FIG. 9 is a perspective view showing an intermediate assembly state of each element constituting the condenser microphone shown in FIG. 8. After the circuit board 2, back electrode board 3, spacer 6, and diaphragm unit 7 are laminated, an adhesive or the like is used. The microphone capsule 19, the shield case 16, and the dust-proof film 17 are configured to be fixed and integrated.

  FIG. 7 is a cross-sectional view showing a configuration of a condenser microphone. The microphone capsule 19 is housed in a shield case 16 to form a casing, and the shield case 16 is covered with an acoustic hole 16a. The dust-proof film 17 is attached to the upper surface side, whereby the condenser microphone 20 is configured.

  In the operation of the capacitor microphone 20 having the above-described configuration, the vibrating membrane 10 having a conductive film on the surface and the back electrode 4 having the electret layer 5 formed on the surface form a capacitor with the spacer 6 interposed therebetween. When the vibrating membrane 10 is displaced by the vibration of air, the capacitor converts the displacement into an electric signal, and this electric signal is transmitted from the vibrating membrane mounting electrode 9 to the circuit board 2 via each connection electrode (not shown). After being guided and processed by the integrated circuit 11, it is output from the output electrode 2 b provided on the back surface of the circuit board 2. The presence of the through-hole 15 makes the operation of the vibrating membrane 10 smooth and ensures acoustic characteristics.

  The conventional condenser microphone 20 described above is small and highly sensitive, but has a problem that it has a large number of manufacturing steps and it is difficult to reduce the manufacturing unit price. In other words, the microphone capsule is assembled as a single unit, and in particular, the process of attaching the dust-proof film one by one after mounting the shield case increases the number of man-hours and increases the burden on the installation equipment. It is difficult to lower the unit price.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of manufacturing a condenser microphone and a condenser microphone that are mass-productive and can reduce the manufacturing unit price.

  In order to solve the above problems, the present invention provides a case in which a circuit board on which electronic components are mounted, a back electrode board in which an electret layer is formed on the back electrode, and a diaphragm unit in which a diaphragm is fixed to a support frame are stacked. In a method of manufacturing a condenser microphone in which the acoustic hole of the case is covered with a dustproof film, an assembly board in which a plurality of the circuit board, the back electrode board, and the vibrating membrane unit are formed on a large board, respectively. Forming the assembly capacitor microphone by laminating the assembly substrate and a dust-proof film of approximately the same size as the assembly substrate, and dividing the assembly capacitor microphone into a plurality of microphone capsules. A method of manufacturing a condenser microphone.

  Furthermore, the present invention is a method for manufacturing a condenser microphone, further comprising a step of storing the microphone capsule in a case.

  This is a condenser microphone manufactured by the above manufacturing method.

  This makes it possible to mass-produce condenser microphones with stable quality, and in particular, greatly reduces the cost of condenser microphones with a dust-proof film.

  Embodiments of the present invention will be described below with reference to FIGS. 1 is a cross-sectional view of a completed condenser microphone according to the present invention, FIG. 2 is a perspective view of an assembly board of elements constituting the condenser microphone of FIG. 1, and FIG. 3 is a partially enlarged perspective view of the assembly board shown in FIG. 4 is a perspective view of an aggregate condenser microphone in which an aggregate substrate and a dust-proof film are laminated and integrated. FIG. 5 is a perspective view of a microphone capsule obtained by dividing the aggregate condenser microphone. FIG. It is a perspective view.

  Next, a method for manufacturing a condenser microphone according to the present invention will be described with reference to FIGS. In addition, the same number is attached | subjected to the same element as each element in the conventional condenser microphone shown in FIGS. 7-9, and description is abbreviate | omitted. In FIG. 2, 2L is an assembly circuit board which is an assembly board of the circuit board 2, 3L is an assembly back electrode board which is an assembly board of the back electrode board 3, and 6L is an assembly spacer which is an assembly board of the spacer 6. , 7L is a collective vibration film unit that is an aggregate substrate of the vibration film unit 7, and 17L is an aggregate dustproof film that is an aggregate of the dustproof film 17, and has a shape substantially the same size as each aggregate substrate.

  FIG. 3 is a partially enlarged perspective view of each assembly substrate in FIG. 2 and illustrates one element formed on each assembly substrate. That is, the circuit board 2 is formed on the collective circuit board 2L. The circuit board 2 is mounted with the integrated circuit 11 and uses the grooves 2La appropriately formed on the collective circuit board 2L. An electrode 2b and the like are formed. A plurality of circuit boards 2 are provided on the collective circuit board 2L as shown in FIG.

  Similarly, a plurality of back electrode substrates 3 are provided on the collective back electrode substrate 3L, a plurality of spacers 6 are provided on the collective spacer 6L, and a plurality of vibration membrane units 7 are provided on the collective vibration membrane unit 7L. It has been. The above is the process of forming each element as an aggregate substrate. In FIG. 2, in order to show that a plurality of elements are formed on each collective substrate, the collective circuit substrate 2L has a plurality of integrated circuits 11 and the collective back electrode substrate 3L has a plurality of elements. A plurality of spacer holes 6a are shown in the back electrode 4, the collective spacer 6L, and a plurality of vibration films 10 are shown in the collective vibration film unit 7L.

  FIG. 4 is a perspective view of the collective condenser microphone 30L, in which the collective circuit board 2L, the collective back electrode board 3L, the collective spacer 6L, the collective vibrating membrane unit 7L, and the collective dust-proof film 17L are stacked. The process which comprises 30L is shown.

  FIG. 5 shows a process of creating a plurality of microphone capsules 30 by dividing the aggregate condenser microphone 30L by a cutting method such as dicing. Further, FIG. 6 shows a process of housing the microphone capsule 30 in the shield case 16. That is, since the dust-proof film 17 is laminated on the upper surface side of the vibrating membrane unit 7 in the microphone capsule 30, it is only necessary to cover the shield case 16 and store it, compared to the conventional assembly process shown in FIG. The deposition process of the dust-proof film 17 is omitted.

  FIG. 1 is a cross-sectional view of the condenser microphone 1 manufactured by the steps shown in FIGS. 2 to 6. The basic configuration is the same as that of the condenser microphone 20 of FIG. 7, except that the condenser microphone 20 is dust-proof. Whereas the film 17 is attached to the upper surface side of the acoustic hole 16a in the shield case 16, the condenser microphone 1 is where the dustproof film 17 covers the acoustic hole 16a in the shield case 16 from the inside.

  As described above, in the present invention, each element is composed of an assembly board, and each assembly board is stacked to create an assembly capacitor microphone. Therefore, it is easy to manage the dimensions and assembly conditions of each element. This produces an enormous effect that enables mass production of condenser microphones with stable quality. In addition, since the dust-proof film is laminated at the same time, the microphone capsule with the dust-proof film can be easily mass-produced. In addition, since the dust-proof film deposition process on the shield case, which has conventionally required a lot of man-hours, can be eliminated, there is an effect that the cost of the condenser microphone can be reduced by drastically reducing the man-hours.

  Furthermore, even in the completed condenser microphone, the dust-proof film that has been deposited on the upper surface of the shield case is stored on the inner side of the shield case, so that problems such as peeling of the dust-proof film do not occur, and reliability This also has an effect in terms of.

It is sectional drawing of the capacitor | condenser microphone in embodiment of this invention. It is a perspective view of the assembly board | substrate of each element which comprises the condenser microphone of this invention. FIG. 3 is a partially enlarged perspective view of the assembly substrate shown in FIG. 2. FIG. 4 is a perspective view of an aggregate condenser microphone in which the aggregate substrate and the dustproof film shown in FIG. 3 are laminated and integrated. It is a perspective view of the microphone capsule which divided | segmented the aggregate | assembly condenser microphone shown in FIG. FIG. 6 is a cross-sectional view of the microphone capsule and the case shown in FIG. 5. It is sectional drawing of the conventional condenser microphone. It is a disassembled perspective view of each element which comprises the condenser microphone shown in FIG. FIG. 9 is a perspective view showing an intermediate assembled state of the condenser microphone shown in FIG. 8.

Explanation of symbols

1,20 Condenser microphone
2 Circuit board 3 Back electrode board 4 Back electrode 5 Electret layer 6 Spacer 7 Vibration film unit 10 Vibration film 16 Shield case 17 Dust-proof film 19, 30 Microphone capsule 30L Aggregate condenser microphone

Claims (3)

A circuit board on which electronic components are mounted, a back electrode board in which an electret layer is formed on the back electrode, and a diaphragm unit with a diaphragm attached to a support frame are stacked and stored in a case. In a method of manufacturing a condenser microphone coated with a dust-proof film, a step of forming a plurality of circuit boards, a back electrode board, and a vibrating membrane unit as an aggregate board on a large substrate, and the aggregate boards. And a step of forming an aggregate condenser microphone by laminating the aggregate substrate and a dustproof film of substantially the same size, and a step of dividing the aggregate condenser microphone into a plurality of microphone capsules. A method of manufacturing a condenser microphone. The method of manufacturing a condenser microphone according to claim 1, further comprising a step of housing the microphone capsule in a case. A condenser microphone manufactured by the manufacturing method according to claim 1.

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