Description
CONDENSER MICROPHONE FOR INSERTING IN MAIN BOARD AND PORTABLE COMMUNICATION DEVICE
HAVING THE SAME
Technical Field
[1] The present invention relates to a condenser microphone for inserting in a main board and a portable communication device having the same. More particularly, the present invention relates to a condenser microphone that can minimize a thickness of a main board when it is mounted on the main board and thus make a portable communication device employing the main board, on which the condenser microphone is mounted, slim. Background Art
[2] Recently, a variety of common multimedia devices such as camcorders, MP3 players, and portable communication devices are generally provided with a sound recording function. Particularly, in order to realize the sound recording function in the multimedia devices that are miniaturized and integrated while maintaining a high performance, microphones that become smaller are mounted in the multimedia devices.
[3] Among the microphones, a condenser microphone has merits that it can be easily made in a small size and has a superior sensitivity property and a high reaction rate. In the condenser microphone, an electric field is formed by a diaphragm and an electrode plate and an electric field variation caused by the vibration of the diaphragm is measured and converted into electric signals. Recently, it becomes possible to further reduce the size of the microphone by utilizing an electret on which electric charges are almost permanently accumulated. The condenser microphone using the electret is referred to as an electret condenser microphone (ECM). The ECMs are classified depending on a location of the electret and the diaphragm into a front type and a back type. In addition, when the diaphragm functions as the electret, the ECM is classified into a foil type.
[4] The ECM includes a diaphragm, a dielectric plate, a spacer ring, an insulation base ring, a conductive base ring, and a printed circuit board, which are orderly stacked in a cylindrical or polygonal container (or case) having a closed end. The container is provided at the closed end with a sound hole. A vibration generated by an external source is transmitted through the sound hole. Further, when the diaphragm, the dielectric plate, the spacer ring, the insulation base ring, and the conductive base ring are received in the case, a rest portion of the case is bent to provide a seal or Ion- gitudinal ends of a PCB and the case are coupled to each other, thereby completing the ECM. At this point, a solder ball is attached on an exposed portion of the PCB to apply a surface mount device (SMD) process or a terminal is formed on the exposed portion of the PCB for the connection with a mother board (or a main board). The ECM provided with the solder ball or the terminal is attached on the mother board through an attaching process such as the SMD process or the soldering process. [5] As shown in FIG. 1, the condenser microphone 1 having the above-described structure is mounted on a main board 2. Describing in more detail with reference to FIG. 2, when a thickness of the main board 2 is "t" and a thickness of the condenser microphone 1 is "T," a thickness of a specific portion of the main board 2 on which the condenser microphone 1 is mounted becomes "t+T." In a case of a portable communication device having the main board 2, a thickness of a region I where the condenser microphone 1 is installed is greater than that of other regions A. Hence, an outer cover 4 of the portable communication device is elevated at a region corresponding to the region A where the condenser microphone 1 is installed. As a result, it is difficult to overcome a limitation in making the portable communication device 3 slim due to the region A of the main board 2 where the condenser microphone 1 is installed. Disclosure of Invention
Technical Problem
[6] Therefore, an object of the present invention is to provide a condenser microphone that is designed to be inserted in a groove formed on a portion of a main board so that thicknesses of the main board and the condenser microphone overlap with each other to thereby reduce a thickness of a region where it is installed, and a portable communication device having the condenser microphone.
[7] Another object of the present invention is to provide a condenser microphone that is designed to be inserted in a groove formed on a portion of a main board through a surface mounting technology so that it can be easily removed from the main board in a case where the condenser microphone mounted on the main board is defective, and a portable communication device having the condenser microphone.
[8] A further object of the present invention is to provide a condenser microphone that is configured to be coupled to a main board by a coupling of a projection thereof to a groove formed on a front side of the main board to thereby enhance an electrical coupling and to be mounted on the main board without using a mounting process such as a soldering process and a surface mounting process. Technical Solution
[9] In order to achieve the objects, the present invention provides a condenser microphone for inserting in a main board, including: a main board; a seating portion engraved on an edge of the main board; a case inserted in the seating portion and having an opened side; a signal conversion unit received in the case; and a printed circuit board for sending an electric signal generated by the signal conversion unit to the main board.
[10] The case includes a bottom portion on a part of an inner surface of which a front or rear surface of the main board contacts; and an extending portion extending from the bottom portion while defining a hollow cavity and having an area less than that of the bottom portion and an opened top.
[11] In another embodiment of the present invention, there is provided a condenser microphone for inserting in a main board, including: a main board; a seating portion engraved on an edge of the main board; a connector inserted in the seating portion; a case inserted in the connector; a signal conversion unit received in the case; and a printed circuit board for sending an electric signal generated by the signal conversion unit to the main board.
[12] The connector includes an insertion groove in which the case is inserted; one or more wings extending outward from the insertion groove; and one or more connection terminals electrically connected to electrode patterns formed on the printed circuit board.
[13] In still another embodiment of the present invention, there is provided a portable communication device including: a main board provided at an edge with an engraved seating portion; a condenser microphone including a case inserted in the seating portion and having an opened side, a signal conversion unit received in the case, and a printed circuit board for sending an electric signal generated by the signal conversion unit to the main board; and a cover enclosing the main board and the condenser microphone.
[14] In still another embodiment of the present invention, there is provided a portable communication device including: a main board provided at an edge with an engraved seating portion; a condenser microphone including a connector inserted in the seating portion, a case inserted in the connector, a signal conversion unit received in the case, and a printed circuit board for sending an electric signal generated by the signal conversion unit to the main board; and a cover enclosing the main board and the condenser microphone.
[15] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention.
[16] [17]
Brief Description of the Drawings
[18] FIG. 1 is a view of a conventional electret microphone mounted on a main board;
[19] FIG. 2 is a partial sectional view of a portable communication device having the main board of FIG. 1 ; [20] FIG. 3 is a perspective view of a condenser microphone for inserting in a main board according to a first embodiment of the present invention; [21] FIGS. 4 and 5 are exploded perspective views of the condenser microphone of FIG.
3; [22] FIG. 6 is a perspective view of a modified example of a case of the condenser microphone of FIG. 3; [23] FIG. 7 is an exploded perspective view of a signal conversion unit depicted in
FIGS. 4 and 5; [24] FIG. 8 is a view illustrating a comparison between thicknesses of a main board and a condenser microphone inserted in the main board; [25] FIG. 9 is a perspective view of a condenser microphone that is inserted in a main board by a connector according to a second embodiment of the present invention; [26] FIGS. 11 and 12 are perspective views of a modified example of the connector and the condenser microphone of the second embodiment; [27] FIG. 13 is a perspective view of a connector structure inserted in a corner region of a main board and a condenser microphone; [28] FIG. 14 is a view of a modified example of the connector of the second embodiment; [29] FIG. 15 is a perspective view of a connector having a connection terminal that is made in the form of a spring; [30] FIG. 16 is a sectional view illustrating an overall thickness of a main board according to an embodiment of the present invention; [31] FIG. 17 is a sectional view of a portable communication device having a main board depicted in FIG. 16; [32] FIG. 18 is a perspective view of an outer cover of the portable communication device of FIG. 17; and [33] FIGS. 19 and 20 of a main board on which one or more terminals and one or more connection terminals are formed and a connector.
Best Mode for Carrying Out the Invention [34] Embodiments of the present invention will now be described in detail with reference to FIGS. 3 through 18. [35] FIG. 3 shows a main board and a condenser microphone for inserting in the main board according to a first embodiment of the present invention.
[36] Referring to FIG. 3, a condenser microphone is designed to be inserted in a main board 100.
[37] The main board 10 is provided at a side of an edge with a seating portion 110 on which the condenser microphone 200 fixedly seats and a terminal 120 contacting an anode and cathode patterns of the condenser microphone 200. When the main board 100 is designed to be applied to a portable communication device, a variety of circuit elements are further provided on the main board to form a circuit pattern for controlling a signal resulting from the contact of a keypad and to transmit a sound signal from the condenser microphone 200 to a base station.
[38] The seating portion 110 is formed on a side of a corner of the main board and a central portion of an edge of the main board 100. However, the seating portion 110 may be formed at any place of the main board 100 depending on a location of the terminal 120 that is formed on a front portion of the main board 100 for the electric connection with the condenser microphone. Particularly, the seating portion 110 may be formed on an edge region and a corner region of the main board 100 considering an insertion direction of the condenser microphone 200. The seating portion 110 is shaped to correspond to an outer shape of the condenser microphone 200 so that the condenser microphone 200 can be easily inserted therein. For example, when a case of the condenser microphone 200 is formed in a cylindrical shape, the seating portion 110 may be engraved in a semicircular shape.
[39] The terminal 120 is formed at a region where it can contact the cathode and anode patterns of the condenser microphone 200 seating on the seating portion 100.
[40] The condenser microphone 200 inserted in the seating portion 110 formed on the main board 100 converts a sound signal input from an external side into an electric signal and sends the electric signal to the main board 100 through the electric connection with the terminal 120 formed on the main board 100. As shown in FIGS. 4 and 5, the condenser microphone 200 includes a case 210 inserted in the seating portion 110 of the main board 100, a signal conversion unit 220 received in the case 220, and a printed circuit board 230 for amplifying and filtering the electric signal converted by the signal conversion unit 220 and sending the amplified and filtered electric signal to the main board 100.
[41] The case 210 has a bottom portion provided with a sound hole 212a through which the sound signal is introduced and an extending portion 214 extending upward from the bottom portion 212 to define a hollow cavity and defining an opened top opposing the bottom portion 212. When the bottom portion 212 is formed in an oval-shape, the extending portion 214 extends vertically from the bottom portion 212 in a circular or polygonal shape having a center identical to that of the oval shape of the bottom portion 212 while forming the hollow cavity and the opened top. The signal conversion unit 220 is inserted into the hollow cavity defined by the extending portion 214 through the opened top 216. As shown in FIG. 6, a portion of the bottom portion 212 may protrudes from the extending portion 214. That is, the bottom portion 212 and the extending portion 214 are not limited to specific shapes. Any shape by which a side of the bottom portion 212 can contact the front surface of the main board 10 by making the bottom portion 212 larger than the opened top 216 will be possible. [42] The signal conversion unit 220 converts the sound signal introduced through the sound hole 212a formed in the case 210 in response to electrostatic capacity. The signal conversion unit 220 may be formed in a variety of forms. For example, as shown in FIG. 7, the signal conversion unit 220 includes a diaphragm 203 having a film 201 and a pola ring 202 that are integrated, a spacer 204, and an insulation ring
205 are stacked on the inner bottom surface of the case 210 in this order. A back electret 206 is inserted in the insulation ring 205 to face the spacer 204. A metal ring 207 is disposed on an inner-upper portion of the insulation ring 205.
[43] The diaphragm 203 is formed by depositing metal on polymer film. The diaphragm
203 is assembled to maintain a minute gap by the pola ring 202 located on the bottom surface. The diaphragm 203 vibrates in response to a sound wave introduced through the sound hole 212a of the case 210.
[44] The back electret 206 is formed by blanking a panel formed of a metal plate on which a dielectric film is attached using a press mold. Upper and lower copper plates disposed on top and bottom surfaces of the back electret 206 are electrically conducted with each other but not conducted with the case 210 by the insulation ring 205 assembled on the circumference of the back electret 206. The back electret 206 is assembled at a location facing the diaphragm 203 and the spacer 204 is disposed between the back electret 206 and the diaphragm 203. Accordingly, the back electret
206 detects the electrostatic capacity that varies in accordance with the vibration of the diaphragm 203, which generated by the sound wave introduced.
[45] The metal ring 207 functions to electrically connect a gate of an electric field effect transistor to the back electret 206. The metal ring 207 is formed by plating a copper plate with gold.
[46] The printed circuit board 230 contacts the top opening 216 of the case 210 and functions to the electric signal converted by the signal conversion unit 220 received in the case 210 to the main board 100 after amplifying and filtering the electric signal. The printed circuit board 230 is formed to be larger than the opening 216 of the case 210 so that a portion thereof can contact a portion of a rear surface of the main board. The printed circuit board 230 may be formed having a shape identical to that of the bottom portion 212 of the case 210. At this point, a contact region between the printed circuit board 230 and the case 210 may be formed through a variety of processes such as a laser welding process, a process using adhesive, a process for allowing protrusions formed on a portion defining the top opening to be fixedly inserted in holes formed on the printed circuit board 230, and the like. A connection terminal 232 providing an electric connection by being coupled to the terminal 120 of the main board 100 may be formed on a region of the printed circuit board, which is larger than the opening 216 of the case 210. The connection terminal 232 is electrically connected to the cathode and anode patterns formed on the printed circuit board 230.
[47] An overall thickness T of the condenser microphone 200 of the first embodiment may be similar to a thickness t of the main board 100. However, when the overall thickness T of the condenser microphone 200 is greater than the thickness t of the main board 100, as shown in FIG. 8, projections 218 are formed on the case 210 and the printed circuit board 230, respectively, so that the contact between the main board 100 and the condenser microphone 200 can be securely maintained, thereby maintaining a function of the condenser microphone 200.
[48] FIG. 9 is a view of a main board 100 and a condenser microphone 200 mounted on the main board according to a second embodiment of the present invention.
[49] Referring to FIG. 9, the condenser microphone 200 is mounted on a connector 300 inserted in a portion of the main board 100.
[50] The main board 100 is provided at a side of an edge with a seating portion 110 in which a portion of the condenser microphone 200 is inserted and a terminal 120 contacting an anode and cathode patterns of the condenser microphone 200.
[51] The seating portion 110 is formed on a side of a corner of the main board and a central portion of an edge of the main board 100. However, the seating portion 110 may be formed at any place of the main board 100 depending on a location of the terminal 120 that is formed on a front portion of the main board 100 for the electric connection with the condenser microphone. The seating portion 110 formed on the main board 100 is shaped to correspond to an outer shape of the connector 300 so that the connector 300 can be easily inserted therein.
[52] Since the condenser microphone of this second embodiment is identical to that of the first embodiment except for the case 210, only the case 210 will be described hereinafter.
[53] The case 210 is provided with a sound hole through which a sound signal is introduced. The case 210 has a bottom portion and an opening portion having a size similar to the bottom portion.
[54] As shown in FIG. 10, the connector 300 includes an insertion groove 310 in which the condenser microphone 200 is inserted, wings 320 fixedly inserted in the seating portion 100 of the main board 100, and a connection terminal 330 connected to anode and cathode patterns formed on the printed circuit board 230 and electrically connected to the terminal 120 of the main board 100.
[55] The insertion groove 310 may be shaped to correspond to a shape of the condenser microphone 200. That is, as shown in FIG. 11, when the condenser microphone 200 is formed in a cylindrical shape, the insertion groove 310 is formed in the cylindrical shape. If the condenser microphone 200 is formed in a hexagonal shape as shown in FIG. 12, the insertion groove 310 is also formed in the hexagonal shape.
[56] The wings 320 are formed extending outward with reference to the insertion groove
310. The wings 320 may be sided in a direction when the seating portion 110 is formed on a corner region of the main board 100 as shown in FIG. 13. That is, the wings 320 may be sized to contact a front surface of the region of the seating portion 110. However, the shape and size of the wings 32 are not specifically limited. As shown in FIG. 14, the wings 320 may be formed not to correspond to the top and bottom of the insertion groove 310. That is, the wings 320 may be formed between a height lower than the top and a height higher than the bottom of the insertion groove 310 and spaced apart from each other by a predetermined distance. The predetermined distance is similar to a thickness of the main board 100 so that the connector 300 can be more securely inserted in the main board 100.
[57] A circuit pattern that can electrically contact a pattern formed on the printed circuit board of the condenser microphone 200 may be formed on the connector 300. This circuit pattern is formed extending from a side of the insertion groove 310 to the connection terminal 330 via the wings 320 and thus each of the patterns of the condenser microphone 200 is electrically connected to the terminal 120 so that an electric signal converted from the sound signal is transmitted.
[58] The connection terminals 330 are respectively connected to the anode and cathode patterns of the condenser microphone 200 to transmit the electric signal by forming an electrical contact with the terminals 120 formed on the main board 100. To this end, the connection terminals 330 may be formed on an inner side of the wings 320 considering the location of the terminals 120 formed on the main board 100. When the terminals 120 is provided in the form of grooves, the connection terminals 330 are provided in the form of projections that can be inserted in the grooves. This groove/ projection coupling structure enhances the coupling force between the main board 100 and the connector 300. Furthermore, as shown in FIG. 15, the connection terminals 330 may be provided in the form of springs. At this point, each of the terminals 120 formed on the main board 100 may have a groove having a width and depth that are similar to those of the spring so that the spring can be fixedly inserted in the groove.
[59] Meanwhile, in the condenser microphone mounted on the main board according to the second embodiment of the present invention, is inserted and fixed in the seating portion formed on the main board in a side direction and thus a thickness of the main board in which the condenser microphone is inserted can be significantly reduced. That is, referring to FIG. 16, when a thickness of the main board is "t" and a thickness of the connector in which the condenser microphone is inserted is "T," the main board 100 in which the condenser microphone is inserted becomes "T." This shows that the thickness of the main board 100 in which the condenser microphone is dramatically reduced. Accordingly, a portable communication device in which the main board according to the embodiment of the present invention is reduced in a height of a region where the condenser microphone 100 is located is significantly reduced as shown in FIGS. 17 and 18. Therefore, a height of a cover 150 is lowered, thereby making the portable communication device optimally slim.
[60] In the condenser microphone mounted in the main board according to the second embodiment of the present invention, the terminals and the connection terminals that are respectively formed on the main board 100 and the connector 300 may be formed as shown in FIGS. 19 and 20. That is, the first and second terminals 120a and 120b formed on a first side of the main board 100 and the third and fourth terminals 120c and 12Od formed on a second side of the main board 100 may be formed such that polarities thereof alternate. The terminals having an identical polarity may be connected to each other by a circuit pattern. Meanwhile, the connection terminals 330 of the connector 300 are formed to correspond to the first through fourth terminals 120a, 120b, 120c, and 12Od, respectively so that the connection terminals 330 can contact the corresponding identical polarity terminals 120a, 120b, 120c, and 12Od when the connector 300 is inserted in the main board 100.
[61]
[62]
[63]
Industrial Applicability
[64] As described above, the condenser microphone of the embodiments of the present invention is designed to be inserted in a groove formed on a portion of a main board so that thicknesses of the main board and the condenser microphone overlap with each other to thereby reduce a thickness of a region where it is installed. Therefore, a thickness of a portable communication device having the condenser microphone can be reduced.
[65] In addition, the condenser microphone of the embodiments of the present invention is designed to be inserted in a groove formed on a portion of a main board through a surface mounting technology and thus the condenser microphone can be easily removed from the main board in a case where the condenser microphone mounted on the main board is defective. [66] Furthermore, since the condenser microphone is configured to be coupled to a main board by a coupling of a projection thereof to a groove formed on a front side of the main board, an electrical connection is enhanced and the condenser microphone can be mounted on the main board without using a mounting process such as a soldering process and a surface mounting process. [67] Finally, the condenser microphone can be easily coupled to a main board by utilizing a connector that can be fixedly inserted in a groove formed on a portion of the main board and can make the main board slim. [68] [69] [70]