JP2011003955A - Condenser microphone unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a condenser microphone unit effectively suppressing generation of noise by securing a sure electric connection state while reducing electric contact points.SOLUTION: The condenser microphone unit is configured by storing a necessary unit member 22, which includes a diaphragm 23 attached to a diaphragm ring 28 through a conductive layer 23b formed on a plastic film 23a, into a unit case 12. In the condenser microphone unit, the diaphragm 23 includes an extension part 24 having a diameter larger than an outer diameter of the diaphragm ring 28, and the diaphragm 23 arranged based on positional relationship in which the diaphragm ring 28 is placed on an inner bottom of the unit case 12 is stored into the unit case 12 so that the conductive layer 23b which is exposed by folding the extension part 24 in a direction reverse to a sending direction when the diaphragm is stored in the unit case 12 together with the other necessary unit member 22 is brought into contact with the inner surface 14b of the unit case 12.

Description

  The present invention provides a condenser microphone unit capable of forming an electrical connection path between a diaphragm and a unit case when a necessary unit member including a diaphragm functioning as a diaphragm is accommodated in the unit case. Technology.

  Usually, a condenser microphone unit is composed of a bottomed cylindrical unit case formed by drawing and a necessary unit member including an impedance converter and a printed circuit board accommodated in the unit case. After the unit member is accommodated in the unit case through the opening, a printed circuit board fixed by caulking and fixing an open edge partitioning the opening is formed so as to seal the opening.

  FIG. 6 is an explanatory view showing an example of a conventional assembly process of a condenser microphone unit having such a configuration, in which (a) is an arrangement before a necessary unit member is accommodated in a unit case. (B) shows a state after the necessary unit member is accommodated in the unit case, and (c) shows a completed state in which the necessary unit member is accommodated in the unit case and the assembly is completed.

  According to the figure, the entire condenser microphone unit 101 is composed of a unit case 102 and a necessary unit member 104 accommodated in the unit case 102.

  In this case, the necessary unit member 104 includes a diaphragm 105 affixed to the diaphragm ring 106 under a predetermined tension, a fixed pole 108 disposed to face the diaphragm 105 via a spacer 107, and the fixed pole. An insulating seat 109 that supports 108, an acoustic resistance material 110 disposed at a predetermined position of the insulating seat 109, and an impedance conversion that seals the opening 103 side of the unit case 102 so as to support the acoustic resistance material 110. And a printed circuit board 111 with a vessel 112. In this case, the diaphragm 105 is affixed to the diaphragm ring 106 using the diaphragm 105 formed to have a diameter slightly larger than the outer diameter of the diaphragm ring 106, and the diaphragm 105 is bonded to the diaphragm ring 106. Thus, the portion protruding from the outer peripheral edge 106a of the diaphragm ring 106 is cut off.

  As shown in FIG. 6A, the necessary unit member 104 having such a configuration has a printed circuit board 111 with respect to the diaphragm 105 arranged so that the diaphragm ring 106 faces the inner bottom surface 102 a of the unit case 102. The fixed pole 108 supported via the insulating seat 109 is faced to each other, and a spacer 107 is interposed between the diaphragm 105 and the fixed pole 108 so as to provide a function as a capacitor. It has become. For this reason, when the diaphragm 105 receives the sound and vibrates, the capacitance between the diaphragm 105 and the fixed electrode 109 can be changed according to the degree of vibration.

  The necessary unit member 104 placed in such an arrangement relationship is accommodated in the unit case 102 as shown in FIG. 6B, and the opening edge 102b partitioning the opening 103 is formed as shown in FIG. The condenser microphone unit 101 is assembled by caulking inward and pressing it toward the printed circuit board 111 as shown in FIG.

  FIG. 7 is an explanatory diagram showing, as patterns (a) to (c), by enlarging a main part of a conventional pasting structure example of a diaphragm ring and a diaphragm as patterns, and the diaphragm 105 in this case is generally circular. A thin plastic film 105a made of polyethylene terephthalate resin (PET) or the like, and a conductive layer 105b provided by vacuum-depositing Au or the like on the side facing the diaphragm ring 106 of the plastic film 105a. . The diaphragm ring 106 is formed using a conductive metal material such as a copper alloy or iron. The contact route on the ground side of the audio signal generated by the vibration of the diaphragm 105 is secured as an impedance conversion circuit including the conductive layer 105 b of the diaphragm 105 → the diaphragm ring 106 → the unit case 102 → the printed circuit board 111.

  By the way, the diaphragm 105 is affixed to the diaphragm ring 106 using the adhesive 115. Since most of the adhesive 115 used in this case is insulative, the path on the ground side of the audio signal is routed. In order to ensure, it is necessary to directly contact the conductive layer 105b of the diaphragm 105 and the diaphragm ring 106 by making the adhesive layer very thin as shown in FIG.

  In addition, as the adhesive 115, there is also an adhesive 115 in which conductive powder is mixed as shown in FIG. 7B so that the conductivity can be ensured even if the adhesive layer is thickened to some extent.

  However, in the case of using the pasting patterns shown in FIGS. 7A and 7B, in both cases, a dimensional change occurs between the adhesive 115 before curing and after curing with shrinkage, and the diaphragm There is a problem that a part of the adhesive 115 protrudes from the inner peripheral side of the ring 106 and the effective capacitance varies.

  FIG. 7 (c) shows an affixing pattern proposed by the applicant of the following Patent Document 1 in order to solve the above-mentioned problems caused by the affixing patterns shown in FIG. 7 (a) and FIG. 7 (b). It is.

JP 2006-157518 A

  That is, in the pasting pattern shown in FIG. 7C, after the adhesive 115 is applied to the surface of the sheet having an uneven surface, the adhesive ring 115 is spread so that the adhesive 115 remains in the concave portion, and then the diaphragm ring 106 is attached. The adhesive 115 is attached to the diaphragm ring 106 side as if it is transferred 7 by being peeled off after being placed and pressed, and the diaphragm 105 is attached to the diaphragm ring 106 via the adhesive 115. It is a thing.

  Therefore, according to the affixing pattern shown in FIG. 7C, the diaphragm 105 and the diaphragm ring 106 can be brought into electrical contact reliably while reducing the amount of the adhesive 115 used, and the diaphragm ring It is possible to eliminate the occurrence of a problem that a part of the adhesive 115 protrudes from the inner peripheral side of 106.

  However, in the case of using the pasting patterns shown in FIGS. 7A to 7C, the sound signal is grounded under the electrical contact route of the conductive layer 105b of the diaphragm 105 → the diaphragm ring 106 → the unit case 102. In addition to ensuring the signal path and increasing the number of electrical contact points, it is easy to generate noise, and the electrical connection state is not necessarily reliable.

  Such inconvenience has been a major factor in generating noise due to electromagnetic waves in, for example, mobile phones because it makes it easier for high-frequency current to enter from uncertain portions of the electrical connection state in the ground-side signal path. . Further, as shown in FIG. 6C, the condenser microphone unit 101 after assembly is completed in a state where the necessary unit member 104 is eccentric in the unit case 102 so that the center axes thereof do not coincide with each other. There was also the problem of being placed.

  In view of the above problems of the prior art, the present invention secures an electrical contact route for a ground-side signal of an audio signal with a more reliable electrical connection state while reducing the number of electrical contact points. It is an object of the present invention to provide a condenser microphone unit that can effectively suppress the generation of noise.

  The present invention has been made in order to achieve the above object, and has a necessary unit member including a diaphragm attached to a diaphragm ring via a conductive layer provided on one side surface of a plastic film. It is accommodated in a unit case made of a conductive metal material having a cylindrical shape, and the open edge of the unit case is caulked and fastened to the outer surface of the printed circuit board constituting the necessary unit member and sealed. In the condenser microphone unit, the diaphragm includes an extending portion formed in a peripheral surface region having a diameter larger than the outer diameter of the diaphragm ring, and the diaphragm ring is placed on the inner bottom surface of the unit case. The diaphragm arranged under the relationship is the unit case together with the other necessary unit members. It is the most important that the conductive portion, which is exposed by folding the extension portion in a direction opposite to the feeding direction when being accommodated in the housing, is accommodated in the unit case in contact with the inner surface of the unit case. It is a feature.

  In this case, the extending portion of the diaphragm is radially cut from the outer peripheral edge to the outer peripheral edge of the diaphragm ring so as to be able to be smoothly turned back when accommodated. Provided with tongue pieces formed separately, or formed through radial mountain fold lines and valley fold lines alternately directed in the center of the circle from the outer peripheral edge to the outer peripheral edge of the diaphragm ring It is preferable to provide the made mountain fold part and valley fold part.

  According to the present invention, the diaphragm has the extending portion folded back in the direction opposite to the feeding direction when the diaphragm is housed in the unit case together with other necessary unit members, and the conductive portion exposed at that time is disposed inside the unit case. The diaphragm ring itself can be made of an insulating material because it can be directly contacted without going through the diaphragm ring, and more contact points can be secured and secured while reducing the number of electrical contact routes. It is possible to effectively suppress the generation of noise due to electromagnetic waves.

  In addition, since the folded extension portion regulates the position of other necessary unit members in the unit case, the axial positions of the necessary unit members are aligned with each other without decentering the entire necessary unit member in the unit case. Can be accommodated.

  In addition, when the extended portion of the diaphragm has tongue pieces formed separately through cuts or has a mountain fold portion and a valley fold portion, the extended portion is placed in the unit case. Not only can it be arranged smoothly, but the entire extending portion can be arranged substantially evenly over the entire circumference on the inner side surface of the unit case.

It is explanatory drawing which shows the example of an assembly process of this invention, (a) is the arrangement | positioning relationship before accommodating a required unit member in a unit case, (b) accommodates a required unit member in a unit case. (C) shows the completed state after the necessary unit members are accommodated in the unit case and the assembly is completed. The positional relationship between the diaphragm and the diaphragm ring constituting the present invention is illustrated in a state before processing necessary to be accommodated in the unit case, in which (a) is a plan view and (b) Shows side end views respectively. FIG. 2 shows an example of a processing pattern for performing processing necessary for accommodating the extended portion of the diaphragm in the state shown in FIG. 2 in the unit case, in which (a) is a plan view, b) shows side end views, respectively. FIG. 2 shows another example of a processing pattern when performing processing necessary for accommodating the extension portion of the diaphragm in the state shown in FIG. 2 in the unit case, in which (a) is a plan view, (B) shows each side end view. It is explanatory drawing which expands a principal part and shows the shape change at the time of sending a diaphragm into a unit case, (a) of which shows the arrangement relation between the unit case and the diaphragm before sending, and (b) shows sending The arrangement relationship between the rear unit case and the diaphragm is shown. It is explanatory drawing which shows the example of the assembly process conventionally performed of the capacitor | condenser microphone unit, of which (a) is the arrangement | positioning relationship before accommodating a required unit member in a unit case, (b) is a unit case (C) shows a completed state after the necessary unit member is accommodated in the unit case and the assembly is completed. Explanatory drawing which expands a principal part and shows as a pattern (a)-(c) the pasting structure of the diaphragm to the diaphragm ring currently performed conventionally.

  According to the assembly process example shown in FIG. 1, the entire condenser microphone unit 11 includes a unit case 12 and a necessary unit member 22 accommodated in the unit case 12.

  Among these, the unit case 12 made of a conductive metal material has a bottomed cylindrical shape including a peripheral wall portion 14 and a bottom portion 15, and an opening portion partitioned by an open edge portion 14 a of the peripheral wall portion 14 on the top surface thereof. 13 is formed.

  Further, the necessary unit member 22 accommodated in the unit case 12 includes a diaphragm 23 attached to the diaphragm ring 28 under a predetermined tension, and a fixed pole 33 disposed to face the diaphragm 23 via a spacer 34. An insulating seat 35 that supports the fixed pole 33, an acoustic resistance material 36 disposed at a predetermined position of the insulating seat 35, and the opening 13 side of the unit case 12 so as to support the acoustic resistance material 36 And at least a printed circuit board 38 with an impedance converter 37 for sealing.

  The diaphragm 23 in this case has an outer diameter that is sufficiently larger than the outer diameter of the diaphragm ring 28, as is apparent from the state shown in FIG. 2 before the processing necessary for accommodating in the unit case 12 is performed. Therefore, the diaphragm ring 28 is attached to the diaphragm ring 28 with a hook-like extending portion 24 projecting from the outer peripheral edge 29 of the diaphragm ring 28 to the peripheral surface region thereof.

  FIG. 3 and FIG. 4 show examples of processing patterns when processing necessary for accommodating the extended portion 24 of the diaphragm 15 in the state shown in FIG. 2 to be accommodated in the unit case 12. In each of these drawings, (a) is a plan view and (b) is a side end view.

  Among these, FIG. 3 shows an appropriate constant interval in the circumferential direction from the outer peripheral edge 24a of the extending portion 24 of the diaphragm 23 to the outer peripheral edge 29 of the diaphragm ring 28. The example of the processing pattern which made the cut | incision 25a radially and originally formed the tongue piece part 25 by each is shown.

  FIG. 4 also shows an appropriate constant interval in the circumferential direction from the outer peripheral edge 24 a of the extending portion 24 of the diaphragm 23 to the outer peripheral edge 29 of the diaphragm ring 28. The example of the process pattern which repeatedly provided the mountain fold part 26 and the valley fold 27 part which are formed via the mountain fold line 26a and the valley fold line 27a which were provided by these is shown.

  The necessary unit member 22 including the diaphragm 23 thus processed and attached to the diaphragm ring 28 is prepared so as to have the arrangement relationship shown in FIG.

  Next, in the direction of the inner bottom surface 15a of the bottom portion 15 of the unit case 12, first, the diaphragm 23 is fed with the diaphragm ring 28 side down. In this case, as shown in FIG. 5, the diaphragm 23 is made of Au or the like on the opposite side of a plastic film 23a such as a thin polyethylene terephthalate resin (PET) having a circular shape and the diaphragm ring 28 of the plastic film 23a. The conductive layer 23b is formed by vacuum deposition or the like. In addition, the diaphragm ring 28 is formed with an adhesive layer 30 in which an adhesive is thinly applied on the side facing the conductive layer 23 b of the diaphragm 23, and is joined to the conductive layer 23 b side of the diaphragm 23 via the adhesive layer 30. Has been.

  In addition, the diaphragm 23 before being fed is arranged such that the extended portion 24 protrudes from the opening 13 of the unit case 12 as shown in FIG. Then, the diaphragm 23 after feeding is formed such that the extending portion 24 of the diaphragm 23 is folded back in the direction opposite to the feeding direction as shown in FIG. 5B, and the conductive layer 23 b is formed on the peripheral wall portion 14 of the unit case 12. It will be in contact with the inner side surface 14b.

  That is, as is apparent from FIGS. 1 (b) and 5 (b), the diaphragm 23 after being sent in has its extended portion 24 folded back to the inner side surface 14 b of the peripheral wall portion 14 in the unit case 12. 23b can be brought into close contact.

  Then, such a feeding of the diaphragm 23 side with respect to the unit case 12 side can be performed more smoothly if the extension portion 24 is processed in the manner shown in FIGS. 3 and 4 in advance.

  That is, according to the processing pattern shown in FIG. 3, the adjacent tongue pieces 25 and 25 can be overlapped with each other through the respective cuts 25 a, so that the extending portion 24 is smoothly fed into the unit case 12. It can be set as a three-dimensional shape.

  Further, according to the processing pattern shown in FIG. 4, the mountain fold portion 26 and the valley fold portion 27 can be formed by folding origami via alternately provided mountain fold lines 26 a and valley fold lines 27 a. Therefore, the extension part 24 can be made into the three-dimensional shape which can be smoothly sent in in the unit case 12 also in this case.

  After the diaphragm 23 is fed into the unit case 12 in this way, a spacer 34 is placed on the plastic film 23 a in the diaphragm 23 supported by the diaphragm ring 28, and the fixed electrode 33 is positioned on the spacer 34. The printed circuit board 37 provided with the insulating material 35, the acoustic resistance material 36, and the impedance converter 38 is placed in the unit case 12 as shown in FIG.

  After the entire necessary unit member 22 is accommodated in the unit case 12, the open edge 14 a of the peripheral wall 14 that partitions the opening 13 of the unit case 12 is folded back to the outer surface 36 a side of the printed circuit board 37. As shown in FIG. 1B, the condenser microphone unit 11 having the opening 13 sealed with the printed circuit board 37 is assembled.

  Next, the operation and effect of the present invention will be described. The extended portion 24 is folded back in the direction opposite to the feeding direction when the diaphragm 23 is housed in the unit case 12 together with the other necessary unit members 22. The electrically conductive portion 23b exposed at this time can be brought into direct contact with the inner side surface 14b of the unit case 12 without the diaphragm ring 23 interposed therebetween.

  That is, the contact route on the ground side of the audio signal generated by the vibration of the diaphragm 23 can be secured as an impedance conversion circuit including the conductive layer 23b → the unit case 12 → the printed circuit board 36 of the diaphragm 23 excluding the diaphragm ring 23. .

  Therefore, in the case of the conventional example shown in FIG. 6, for example, the conductive layer 105b of the diaphragm 105 → the diaphragm ring 106 → the unit case 102 → the contact route on the ground side of the audio signal secured as an impedance conversion circuit including the printed circuit board 111. In comparison, the number of electrical contact routes can be reduced as much as it is no longer necessary to pass through the diaphragm ring, and noise generation can be suppressed accordingly.

  In addition, since the conductive portion 23b that the extended portion 24 is folded and exposed can be directly brought into contact with the inner side surface 14b of the unit case 12 under a planar shape, The state can be improved, and the generation of noise due to electromagnetic waves can be effectively suppressed.

  Moreover, since the extended extension part 24 restrict | limits the position of the other required unit member 22 from the circumference | surroundings within the unit case 12, the whole required unit member 22 is decentered in the unit case 12. It is possible to accommodate the axial positions of each other without matching.

  In particular, the extended portion 24 of the diaphragm 23 has tongue pieces 25 formed separately through cuts 25a as shown in FIG. 3, or a mountain fold 26 and a valley fold 27 as shown in FIG. , The extended portion 24 can be smoothly arranged in the unit case 12, and the entire extended portion 24 is substantially extended over the entire circumference of the unit case 12 on the inner surface 14 b side. Since they can be arranged evenly, the entire necessary unit member 22 can be accommodated in the unit case 12 with the axial center positions thereof accurately aligned.

  The diaphragm ring 28 itself can be formed using a conventional conductive material, or can be formed using an insulating material such as ceramic, so that a member with a good cost balance can be selected. In addition to being able to gain a degree, it can also contribute to the enrichment of technology.

  The above is the description of the present invention based on the illustrated example, and the specific configuration is not limited thereto. For example, the extending portion 24 of the diaphragm 23 may be accommodated in the unit case 12 as it is without being provided with the notch 25a or the formation of the mountain fold portion 26 and the valley fold portion 27. Good. Further, when the extended portion 24 of the diaphragm 23 is accommodated at a predetermined position in the unit case 12, as long as the outer peripheral edge 24 a is at a position lower than the position of the printed circuit board 36, the specific extension length thereof will be described. You can choose freely.

DESCRIPTION OF SYMBOLS 11 Condenser microphone unit 12 Unit case 13 Opening part 14 Perimeter wall part 14a Open edge part 14b Inner side surface 15 Bottom part 15a Inner bottom surface 22 Necessary unit member 23 Diaphragm 23a Plastic film 23b Conductive layer 24 Extension part 24a Outer peripheral edge 25 Tongue piece part 25a Notch 26 Mountain Folding Section 26a Mountain Folding Line 27 Valley Folding Section 27a Valley Folding Line 28 Diaphragm Ring 29 Outer Periphery 30 Adhesive Layer 33 Fixed Electrode 34 Spacer 35 Acoustic Resistive Material 36 Printed Circuit Board 36a Outer Surface 37 Impedance Converter

Claims (3)

A necessary unit member including a diaphragm attached to a diaphragm ring via a conductive layer provided on one side surface of a plastic film is accommodated in a unit case made of a conductive metal material having a bottomed cylindrical shape. In the condenser microphone unit that is sealed by caulking the open edge of the unit case against the outer surface of the printed circuit board constituting the necessary unit member,
The diaphragm includes an extending portion formed in a peripheral surface region having a diameter larger than the outer diameter of the diaphragm ring,
The diaphragm arranged under a positional relationship in which the diaphragm ring is placed on the inner bottom surface of the unit case is opposite to the feeding direction when the diaphragm ring is housed in the unit case together with the other necessary unit members. A condenser microphone unit characterized in that the conductive portion that is exposed when the extended portion is folded back is accommodated in the unit case in contact with the inner surface of the unit case.   The extending portions of the diaphragm are formed separately by making radial cuts in the direction of the center from the outer peripheral edge to the outer peripheral edge of the diaphragm ring in order to enable smooth folding when housed. The condenser microphone unit according to claim 1, further comprising a tongue portion.   The extended portion of the diaphragm has radial mountain fold lines and valley folds alternately oriented in a circular direction from the outer peripheral edge to the outer peripheral edge of the diaphragm ring in order to enable smooth folding when housed. The condenser microphone unit according to claim 1, further comprising a mountain fold portion and a valley fold portion formed via a line.

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