KR100696166B1 - Electret Condenser Microphone Include Wirebonding Printed Ciruit Board And Fabricating Method Thereof - Google Patents

Abstract

The present invention relates to a printed circuit board on which circuit elements are mounted by wire bonding, an electret condenser microphone and a method of manufacturing a printed circuit board.

A method for manufacturing an electret condenser microphone according to the present invention includes a printed circuit in which an electret, a diaphragm, a bipolar plate, a spacer, a first base ring and a second base ring, a circuit element, and a circuit pattern are accommodated in a case by wire bonding. A method of manufacturing an electret condenser microphone having a substrate, the method comprising: forming a primary circuit pattern divided into one or more blocks by using a primary metal on a substrate, and forming a plating bridge for electrically connecting the blocks; And forming a secondary circuit pattern by plating a secondary metal on the primary circuit pattern connected by the plating bridge, and forming a tertiary circuit pattern by using a tertiary metal on the secondary circuit pattern. Completing a pattern, removing the plating bridge, and attaching a circuit element on the substrate from which the plating bridge is removed. And, a step for wrapping the finished circuit patterns and the circuit elements and the steps, the circuit pattern, the wires and the circuit element for electrically connecting a wire with an insulating material.

Description

Electret Condenser Microphone Include Wirebonding Printed Ciruit Board And Fabricating Method Thereof}

1 is a schematic view showing a circuit device and a PCB mounted using a SMD method on a printed circuit board.

Figure 2 is a simplified perspective view of an electret condenser microphone having a wire bonded printed circuit board according to the present invention.

Figure 3a is a perspective view showing in detail the lower surface.

Figure 3b is a perspective view showing the upper surface in more detail.

4 is a cross-sectional view schematically illustrating a cross section of the wire bonding PCB of FIG. 3.

5 is a flow chart briefly showing a method of manufacturing a wirebonding PCB.

6 is a view showing a circuit pattern and a plating bridge.

7 is a view for explaining a multilayer plating method.

8 is a view for explaining a method of manufacturing a wire bonded printed circuit board.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electret condenser microphones, and more particularly, to a printed circuit board on which circuit elements are mounted by wire bonding, and a method of manufacturing an electret condenser microphone and a printed circuit board having the same.

Recently, multimedia devices that are commonly encountered in the surrounding area, such as moving picture experts group layer 3 (MP3), camcorders, and mobile devices, can transmit or record sound generated from the surrounding area. Donation that can be provided is universally provided. In particular, one of the main reasons why such a recording function can play a role in the miniaturized and high-performance multimedia devices is the development of a microphone that is miniaturized and mounted inside the multimedia device.

The microphone is typically a dynamic microphone using a magnet, or a condenser microphone using a principle of a capacitor (or a capacitor, a condenser or a capacitor). In the case of a dynamic microphone, induction electromotive force is used to store a magnet capable of forming a constant magnetic field (or magnetic field) inside the microphone. In addition, the coil is connected to the diaphragm and flows inside the magnetic field. When the coil is shaken in the magnetic field according to the vibration of the diaphragm, the induced electromotive force is generated in the coil by the magnetic flux. Dynamic microphones use the principle of signaling this induced electromotive force. These dynamic microphones are mechanically robust and are advantageous for use in harsh environments where many people use them or use them roughly. On the other hand, since the magnet should be housed inside the microphone, it is not easy to miniaturize, convert the voice signal into mechanical movement, generate induced electromotive force by mechanical change, and convert the generated induced electromotive force into a signal. Therefore, compared with condenser microphones, there is a disadvantage in that the reaction speed is slow and the sensitivity characteristics are inferior.

On the other hand, in the case of condenser microphones, mechanical robustness is inferior to that of dynamic microphones, but it is relatively easy to miniaturize, has a fast reaction speed, and has good sensitivity characteristics. Such condenser microphones are classified into omnidirectional condenser microphones and directional condenser microphones according to their directivity characteristics, and directional microphones are further divided into bidirectional and unidirectional condenser microphones.

The condenser microphone uses the principle of forming an electric field by the diaphragm and the bipolar plate, and converting the amount of the electric field formed by the vibration of the diaphragm into an electrical signal. To this end, the condenser microphone must be supplied with power to at least one of the diaphragm and the bipolar plate to form an electrostatic field. Therefore, until recently, an external power source has been used in the form of applying one of the two plates or the positive electrode plate. Recently, an electret capable of semi-permanent storage of electric charges has been developed. Electret condenser Microphone (hereinafter referred to as "ECM") has been developed and widely used.

The condenser microphone using this electret provided an opportunity for the condenser microphone to be further miniaturized because the use of the electret does not require a separate power source for generating an electrostatic field from the outside. The ECM is classified into a front type ECM, a back type ECM, and a foil type ECM according to the position and role of the electret. However, in the case of the front-type ECM, there is a manufacturing problem in that the electret is heat-sealed to the case, and in the case of the foil-type ECM, the diaphragm also serves as the electret, so that the sensitivity characteristic is not good. For this reason, in recent years, the back type ECM in which an electret is located in a bipolar plate is mainly used.

The ECM is used in a form in which a diaphragm, a dielectric plate, a spacer, an insulating and conductive base ring, and a printed circuit board (hereinafter referred to as "PCB") are sequentially stacked inside the case. The cylindrical case is provided on one side (which is divided into an upper surface and a lower surface), that is, the lower surface is closed, and the lower surface is formed with sound holes for transmitting sound pressure by sound. When the diaphragm, the dielectric plate, the spacer, and the base rings are accommodated in the cylindrical case, the PCB is sealed using a welding method of bonding or welding the ends of the upper surface (or opening) of the case. Alternatively, the PCB is also housed in the case, the upper surface is formed a little longer, and the case is sealed by a method of curing the formed upper surface.

In particular, the PCB used in the ECM has a circuit or terminal formed on each of the upper side (top side) and the lower side (bottom side, bottom side), and the upper side is used for connection to the outside, and the lower side Circuits are configured for amplifying and filtering the signals of the ECM.

The upper surface is formed with a terminal for connecting to the outside, or a solder ball (Solder Ball) for applying the SMD (Sruface Mount Devices) method is attached. On the other hand, an amplification circuit for amplifying the electric signal from the electrode plate and a filter circuit for removing noise are formed on the lower surface. The amplification circuit and the filter circuit are generally attached in the form of a bare chip to reduce the size of the ECM.

FIG. 1 is a view schematically illustrating a circuit device and a PCB mounted on a printed circuit board by using an SMD method.

Referring to FIG. 1, a pattern 64 is formed on a PCB to serve as a conductor of a circuit. The pad 65 as shown in FIG. 1 is formed at the end of the pattern 64 to provide a position to which the circuit element 61 is to be attached. In this case, the circuit device 61 mounted using the SMD method is provided in a form in which a solder ball 62 for the SMD method is attached to a terminal portion of the circuit device 61. The circuit device provided with the solder balls 62 attached thereto is mounted on the PCB by some pressing and soldering processes. In addition, where the solder ball 62 is attached, terminals for mounting on the PCB may be formed when the SMD method is not used.

However, when the circuit device is mounted on the PCB by such a method, there is a problem in that contact defects between the PCB and the circuit device 61, chip damage, and detachment of the solder ball 62 occur frequently. These problems are caused when the solder ball 62 exceeds the reflow over due to the difference between the thermal expansion coefficients of the solder ball 62 and the PCB, or a crack occurs in the solder ball 62. In addition, when mounting the circuit element to the PCB by using the SMD method, there is a problem that the manufacturing cost increases because the solder ball 62 to be attached to the circuit element to withstand the reflow of the SMD.

In addition, since the size of the ECM is very small, the size of the circuit element mounted thereon is also reduced. As a result, a detachment phenomenon often occurs in which the ordinary solder ball is separated from the circuit element 61 during transportation or even by a slight impact. In particular, since it is impossible to find all of the circuit elements 61 detached through visual inspection, when mounting them on a PCB, a problem may occur that leads to a defect of the PCB itself.

More problematically, since the circuit elements mounted on the PCB in such a SMD method use expensive chip-type devices such as FET (Field Effect Transistor), IC (Integrated Circuit) and ASIC (Application Specific Integrated Circuit), The defects that occur in such chip type circuit elements have a problem that leads to an increase in manufacturing cost.

Accordingly, an object of the present invention is to provide a printed circuit board on which a circuit element is mounted by wire bonding, an electret condenser microphone and a method of manufacturing the printed circuit board having the same.

In addition, another object of the present invention is to provide a plating bridge and connecting bridge that can facilitate the plating of the circuit pattern, while presenting in detail the material, thickness and plating method of the circuit pattern metal suitable for wire bonding, It is to make and use wire-bonded printed circuit board easily and inexpensively.

Another object of the present invention is to provide a procedure for manufacturing an electret condenser microphone in detail, and to propose a method of simultaneously plating a circuit pattern and an electrode, so that the process can be performed more simply and inexpensively.

In order to achieve the above object, an electret condenser microphone having a wire-bonded printed circuit board according to the present invention includes a case, an electret, a diaphragm, a bipolar plate, a spacer, a first base ring, and a second base ring, which are housed in the case. At least one circuit element for amplifying and filtering an electrical signal from the diaphragm and the bipolar plate, and a circuit pattern for providing a conductive path to the circuit element, wherein the circuit element and the circuit pattern are wire bonded. It is provided with a wire bonding external circuit board connected to.

The circuit device may be provided in the form of an integrated circuit or an ASIC including at least one of a capacitor and a field effect transistor, and the circuit pattern may be nickel and gold plated by an electrolytic soft plating method, and the material of the wire. Silver is used.

The circuit pattern is divided into one or more separate blocks, and the printed board includes the circuit pattern and a plating bridge for electrically connecting the blocks for the plating, wherein the plating bridge is lasered after completion of the plating. It is removed by the trimming method.

The wire-bonded printed circuit board has at least one electrode formed on a surface opposite to the surface on which the circuit pattern is formed, and the circuit pattern and the electrode are electrically connected by at least one through hole.

In addition, the manufacturing method of the electret condenser microphone according to the present invention is connected to the electret, the diaphragm, the bipolar plate, the spacer, the first base ring and the second base ring, the circuit element and the circuit pattern is housed in the case by wire bonding method A method of manufacturing an electret condenser microphone having a printed circuit board, the method comprising: forming a primary circuit pattern divided into one or more blocks by using a primary metal on a substrate, and plating for electrically connecting the blocks; Forming a bridge, forming a secondary circuit pattern by plating a secondary metal on the primary circuit pattern connected by the plating bridge, and forming a tertiary circuit pattern by using a tertiary metal on the secondary circuit pattern. Forming a circuit pattern, removing the plating bridge, and forming a circuit device on the substrate from which the plating bridge is removed. Attaching, electrically connecting the circuit element with the completed circuit pattern by a wire, and wrapping the circuit pattern, the wire, and the circuit element with an insulating material.

The primary metal is copper, the secondary metal is nickel, the tertiary metal is gold, and the nickel is plated to a thickness of 0.1 to several tens of micrometers, preferably 1 to 10 micrometers thick. Plated with. In addition, the gold is plated to a thickness of 0.05 to 10 micrometers, preferably plated to a thickness of 0.01 to 1 micrometer.

The plating bridge is integrally formed with the primary circuit pattern, and at least one of forming the primary circuit pattern or forming the secondary circuit pattern includes connecting bridges for connecting to an external power source. It further comprises the step of forming. The plating method is an electrolytic soft plating method, and forming an electrode on the substrate surface on which the circuit pattern is not formed, and at least one through hole for electrically connecting the electrode and the circuit pattern. And forming a conductive metal material in the through hole.

Other features and effects of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings. Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 2 to 8.

2 is a perspective view schematically showing an electret condenser microphone having a wire bonded printed circuit board according to the present invention.

Referring to FIG. 2, the wire-bonded printed circuit board according to the present invention includes a wire-bonded printed circuit board 1, a diaphragm 2, a spacer 3, a bipolar plate 4, a first base ring 6, and a first 2 base ring 5 and case 7 are provided.

Wire Bonding PCB 1 is formed with circuits and terminals for amplifying and filtering an electric signal generated by a change in an electric field and transmitting the result to the outside. To this end, the wire bonding PCB 1 includes an amplifying circuit for amplifying a change in the electric field and a filter circuit for filtering noise. Here, the amplification circuit mainly uses a field effect transistor (hereinafter referred to as "FET"), and the filter circuit is referred to as a multilayer ceramic capacitor (hereinafter referred to as "MLCC") composed of one or more capacitors. It is configured using Such a filter circuit or amplification circuit may be provided in the form of an integrated circuit (IC) or an application specific integrated circuit (ASIC). As described above, a circuit device provided in a chip form is attached by die bonding to a lower surface of a printed circuit board. At this time, the circuit elements of the circuit elements are not directly connected to the PCB pattern directly, but in an inverted form, that is, where no terminal portions of the circuit elements are attached to the lower surface of the PCB. When the circuit element is attached to the PCB, the terminal portion of the circuit element and the pattern of the PCB are wire bonded to be electrically connected. This will be described later in more detail. To this end, a circuit pattern is formed on the wire bonding PCB 1 by an electrolytic soft plating method. This is a method for more easily bonding and increasing the strength of the bonding when the circuit element is connected to the pattern by wire bonding. In more detail, the wire bonding PCB 1 forms a primary circuit pattern using copper on a base plate made of an insulating resin such as an epoxy resin. When the primary circuit pattern is formed, nickel (Ni) is plated on the primary circuit pattern to form a secondary circuit pattern. When the secondary circuit pattern is formed, a tertiary circuit pattern is formed on the secondary circuit pattern by using gold (Au). An electrolytic soft plating method is used as a method for forming the secondary and tertiary circuit patterns. When the tertiary circuit pattern is formed by the electrolytic soft plating method, the circuit element and the pattern are electrically connected by using the wire bonding method. Since the circuit pattern formed by the electrolytic soft plating method is finely roughened, the wires are easily attached during wire bonding. Here, the reason for forming the secondary circuit pattern by nickel is to use as a medium metal to compensate for the conductive properties of copper and to compensate for the weak coupling of gold and copper, which is a material of the tertiary circuit pattern.

The diaphragm 2 vibrates by the sound pressure of the sound transmitted through the sound hole 8 of the case 7 to generate a change in the electric field. To this end, the diaphragm 2 serves as an electrode plate for generating an electric field together with the bipolar plate 4. The diaphragm 2 is divided into a diaphragm and a polar ring, and the diaphragm changes the electric field by vibration by sound pressure. To this end, the vibration membrane is produced by sputtering nickel (Ni) or gold (Au) for conductive properties on a polymer film such as polyethylene terphthalate (PET) having a thickness of several micrometers. Polar ring is used to separate and maintain the gap between the vibration membrane and the inner surface of the case (7), the vibration membrane is attached to one surface. In addition, the polar ring electrically connects the wire bonding PCB 1 and the vibrating membrane via the case 7. The polar ring is manufactured in the form of a donut and a ring using a metal such as copper and an alloy thereof.

The spacer 3 is positioned between the diaphragm 2 and the bipolar plate 4 so that the diaphragm 2 and the bipolar plate 4 are arranged in parallel at a predetermined distance. In addition, the spacer 3 allows the diaphragm 2 and the bipolar plate 4 to be electrically insulated from each other, and is manufactured in the form of a donut or a ring by using a material having good insulation properties such as an acrylic resin.

A back plate (or dielectric plate, BE, 4) forms an electrostatic field together with the diaphragm 2 to convert sound pressure into an electrical signal. For this purpose, the bipolar plate 4 is composed of an electret polymer film and a metal plate. The electret polymer film is semi-permanently charged and forms an electrostatic field. The bipolar plate 4 is a polymer film such as PTFE (Poly Tetra Fluoro Ethylene), PFA (Per Fluoro Alkoxy), or FEP (Fluoro Ethylene Propylene). It is made by injection. In this case, a metal such as copper, bronze, brass, and phosphor bronze is used as the cathode.

The first base ring (or insulating base ring 6) is positioned between the bipolar plate 4 and the case 7 to electrically insulate the bipolar plate 4 and the case 7. The first base ring 5 is made of a cylindrical or polygonal column with a space formed therein, the side portion is in contact with the case 7, and the second base ring 5 is accommodated in the inner space. In addition, the upper surface of the first base ring 6 supports the spacer 5 and serves to firmly fix the internal components by the case 7 and the spacer 3.

The second base ring (or conductive base ring 5) serves to electrically connect the bipolar plate 4 and the wire bonding PCB 1. The outer diameter of the second base ring 5 is made to be the size corresponding to the inner diameter of the first base ring 6, so that the second base ring 5 does not vibrate due to external impact. The second base ring 5 is also made of a cylindrical or polygonal column in a ring shape, the bottom surface of which is in contact with the bipolar plate 4 and the top surface of the wire bonding PCB 1.

The case 7 houses the diaphragm 2, the spacer 3, the bipolar plate 4, the first base ring 5 and the second base ring 6 therein, and protects the internal components from external shocks. Protect. In addition, the case 7 serves to shield the acoustic noise and electromagnetic noise introduced from the outside to facilitate the electrical signal conversion of the sound. Then, the case 7 electrically connects the diaphragm 3 and the wire bonding PCB 1. To this end, the case 7 is made of a cylindrical shape, one side is a blockage except for the sound hole (or sound inlet hole, 11) through which sound is introduced, and the other side is provided in an open form (opening). In the case 1, the diaphragm 2, the spacer 3, the bipolar plate 4, and the first and second base rings 5 and 6 are sequentially stacked inside the lower surface where the sound holes are formed. In addition, the opening of the case 7 is coupled to and sealed by the side, side edges of the wire-bonding PCB 1 by adhesion or welding, or the like. In addition, the wire bonding PCB 1 is housed inside the case 7, and the end of the opening of the case 7 is cured and sealed. The case 7 is made of a conductive metal such as aluminum and copper to shield noise, and may be used in the form of plating of gold (Au) or nickel (Ni) to improve electrical conductivity and prevent corrosion. have.

Here, the condenser microphone described with reference to FIG. 2 has been described using a back type condenser microphone as an example. The technical idea of the present invention is equally applied to a foil type and a front type condenser microphone. It is possible to do

3 is a view illustrating the wire bonding printed circuit board in more detail. FIG. 3A is a perspective view showing the lower surface in detail, and FIG. 3B is a view showing the upper surface in more detail.

3A and 3B, a circuit pattern 12 of copper / nickel / gold is formed on the bottom portion 11 of the wire bonding PCB 1. The circuit pattern 12 connects the diaphragm 2 or the bipolar plate 4 and the circuit elements 13 and serves to connect the circuit elements 13. Circuit elements 13 such as filter elements and amplification elements are attached to the wire bonding PCB 1 on which the circuit patterns 12 are formed.

Circuit elements 13 attached to the wire bonding PCB 1 are attached to expose the connection terminal 18. That is, the circuit element 13 is attached so as to face the upper direction which is not in contact with the lower surface portion 11. The circuit element 13 thus attached is electrically connected to the circuit pattern 12 by a conductive wire 14 using copper, nickel or gold. To this end, the circuit pattern 12 is manufactured by an electrolytic soft plating method so that the conductive wire 14 is easily and firmly contacted with the circuit pattern 12.

In addition, a plurality of through holes 16 are formed in the lower surface portion 11 for electrically connecting the electrode 15 of the upper surface portion 17 and the circuit pattern 13 of the lower surface portion 11. The through hole 16 is filled with a metal compound and a metal cream, and electrically connects the electrode 15 and the circuit pattern 13 with the conductive properties of the metal compound and the metal cream. You can connect.

In addition, as shown in FIG. 2B, at least a bipolar electrode 15 is formed on the upper surface 17 of the wire bonding PCB 1. The electrode 15 is attached with a solder ball or a terminal and used as a means for connection with an external device. Accordingly, signals generated by the circuit element 13 of the lower surface portion 11 are transmitted to the electrode 15 through the through hole 16, and the signals transmitted to the electrode 15 are external conductors coupled to the electrodes, It is transmitted to an external device through a circuit.

4 is a cross-sectional view briefly illustrating a cross section of the wire bonding PCB of FIG. 3.

FIG. 4 is a view schematically illustrating a cross section of a portion to which a circuit device is attached in FIG. 3. As can be seen in FIG. 4, the lower surface portion 11 and the upper surface portion 17 are formed on the upper and lower surfaces of the substrate 20 with the substrate 20 interposed therebetween. First, the electrodes 15a and 15b described in FIG. 3 are formed on the upper surface portion 17. And, the solder ball 21 for applying the SMD method is attached on the electrode (15a). In addition, a through hole 16 is formed in the upper surface portion 17 electrode 15b. The through hole 16 is in contact with the electrode 15b of the upper surface portion 17 and the circuit pattern 12 of the lower surface portion 11 to electrically connect each other. As described above, the through hole 16 is filled with a material having conductive properties such as metal cream or compound during the manufacturing process.

In addition, a circuit element 13 is attached to the lower surface portion 11 as shown in FIG. 3. In FIG. 4, the circuit element 13 is attached to the substrate 20. However, in some cases, the circuit element 13 may be attached to the circuit pattern 12. As shown in FIG. 3, the upper portion of the circuit element 13 is attached in contact with the substrate 20. This was conventionally a method in which the terminal portion 18 of the circuit element 13 is directly attached to the circuit pattern 12 by a method such as soldering. However, in the present invention, as shown in FIG. 4, the terminal portion 13 and the circuit pattern ( 12 is connected by the wire 14. That is, when the circuit element 13 is attached to the substrate 20 in an inverted form, the terminal portion 18 of the circuit element 13 is not directly connected to the circuit pattern 12, but the inner direction of the case 7. Is exposed. After attachment of the circuitry 13, the exposed terminal portion 18 is connected with the circuit pattern 12 by one or more wires 18. Through this, the circuit element 13 is electrically connected to the terminal 15 of the upper surface portion 17 or the separated circuit patterns 12. At this time, the material of the wire 14 is a metal having good conductive characteristics such as copper, nickel, aluminum, and gold, and it is particularly preferable to use gold which can easily mold the wire 14.

As such, when the terminal portion 18 and the circuit pattern 12 are connected by the wire 14, encapsulation is performed using epoxy resin 19 to surround the circuit element 13, in particular, the wire 14. Done. This is to insulate the circuit pattern 12, the wire 14, and the circuit element 13 from the outside, and to prevent the wire 14 from being disconnected or shorted from an external impact. In addition, it is preferable that the epoxy resin 19 is also applied on the circuit pattern 12 so that the remaining circuit pattern 12 is not exposed in a non-insulated state.

5 is a flowchart briefly illustrating a method of manufacturing a wire bonded PCB.

Referring to FIG. 5, the wire bonding printed circuit board manufacturing method may be largely divided into a substrate manufacturing step S10, a plating step S20, and a circuit element attaching step S30.

In the substrate manufacturing step of S10, the primary circuit pattern 22a or the electrode 25 is formed on the prepared substrate 20 by using a primary metal such as copper. At this time, a plating bridge for plating is formed together on the primary circuit pattern 22a. Here, the plating bridge is a means for electrically connecting the separated circuit pattern 22 for electrolytic soft plating. Detailed description of this plating bridge will be described later with reference to FIG. 5.

When the molding of the circuit pattern 22 including the plating bridge is completed in step S10, plating for forming the secondary circuit pattern and the tertiary circuit pattern is performed on the circuit pattern 22 in step S20. To this end, step S20 includes forming a secondary circuit pattern using a secondary metal such as nickel, forming a tertiary circuit pattern using a tertiary metal such as gold, and removing the plating bridge. Include.

The step S20 may include plating the electrode 25 of the upper surface portion. Also in the case of plating the electrode 25 of the upper surface portion 17, the plating step using the secondary metal and the plating step using the tertiary metal are included, as in the case of plating the circuit pattern 22.

In order to plate the secondary metal, when a potential is applied to the primary circuit pattern 22a electrically connected by the plating bridge, and the substrate 20 is placed in a solution containing the secondary metal material or in the ion, the primary circuit A secondary metal material is plated on the pattern 22a. Thereafter, the tertiary metal is plated on the secondary circuit pattern 22b in the same manner.

When the plating is completed, the plating bridge, which was included in the circuit pattern 22 for plating, is removed. At this time, it is preferable to melt and remove the plating bridge to facilitate recycling of the plating bridge. To this end, the plating bridge is removed by trimming using a laser. This laser trimming method has advantages of easy local removal of patterns by using the sophistication of the laser, and has a simpler number of processes than the etching process.

In addition, a step of forming a through hole between steps S10 and S20, and filling the conductive material such as a metal compound, a metal cream in the through hole. This is because, after the circuit element is attached, it is difficult to proceed with the process of forming the through hole and filling the conductive material. If the through-hole and the conductive material are inserted after the circuit device is attached, the already-attached circuit device may be separated or damaged from the substrate. Therefore, the through-holes are formed and the conductive material is formed before the circuit device is attached. The insertion process must be done.

As such, when the manufacturing of the substrate 20 is finished by the plating step S20, the circuit device is attached onto the substrate 20 having the circuit pattern 22 in step S30. The step S30 includes attaching circuit elements, connecting circuit elements and circuit patterns by wires, and encapsulating the circuit elements and circuit patterns using an insulating material such as epoxy resin.

In the step S30, first, the circuit element is attached to the substrate 20 having the circuit pattern completed by the plating process. In this case, the circuit element is attached to the substrate 20 in an inverted form so that the terminal portion is exposed. After attaching the circuit element, the exposed terminal portion and the circuit pattern are connected by a conductive wire such as gold. When the forming of the wire connecting the circuit element and the circuit pattern is finished, an insulating material such as hydroxy resin is applied onto the circuit element and the circuit pattern to encapsulate it.

6 is a diagram illustrating a circuit pattern and a plating bridge, and FIG. 7 is a diagram for describing a multilayer plating method.

As shown in FIG. 6, the plating bridge 35 is formed on the substrate 30 together with the circuit pattern 33 in step S10. At this time, the circuit pattern 33 is formed, as can be seen in Figure 6, has one or more disconnected blocks for the configuration of the circuit. In order to plate a circuit pattern composed of disconnected blocks, a potential must be applied to each block, and for this purpose, a method such as connecting each block with an electrode for plating must be applied. However, when using the method of connecting each block with the plating electrode, the procedure for the progress of the process is complicated, and the connection process with the plating electrode must be precise, there is a problem that the cost for manufacturing the PCB increases. .

However, in the present invention, each circuit pattern block 33a to 33e is manufactured in the form of being connected by a plating bridge. A connection bridge 35b for connecting to the external plating electrode is formed on a portion of the circuit pattern to connect the external plating electrode. This makes it possible to apply a potential to the circuit pattern without going through the process of connecting the respective circuit pattern blocks. In addition, when plating is completed, the plating bridge and the connecting bridge are easily removed by an etching or a lattice trimming method, so that a process for plating the circuit pattern is easily performed.

7 illustrates a plating method using a multilayer substrate, which is one of plating methods used in the related art. In the method shown in FIG. 6, the electrode substrate is placed on the back side of the circuit board on which the circuit pattern is formed, that is, on the side where the circuit pattern is not formed, and the circuit board and the electrode substrate are connected and plated through the through holes. In this case, it is cumbersome to form at least one through hole in each circuit pattern block, and the inconvenience of having to employ an electrode substrate separately is accompanied. In addition, in order to fabricate a printed circuit board using both surfaces, such as ECM, a separate double-sided substrate is placed on the upper and lower surfaces of the electrode substrate, and after the plating is performed, these processes are complicated. On the other hand, in the plating using the plating bridge of the present invention, through-hole formation and metal material formation are performed before the formation of the secondary circuit pattern to connect the upper and lower surfaces, and the connecting bridge of the double-sided substrate on which the through-hole is formed. When the external voltage is applied to the plating, the secondary and tertiary circuit patterns can be easily formed. In addition, in the manufacturing method according to the present invention, when the number of plating targets and the number of times for each block are different, it is only necessary to remove the connection bridges between the blocks, thereby making it possible to easily form various circuit patterns.

FIG. 8 is a view for explaining a method of manufacturing a wire bonded printed circuit board. FIG.

In particular, FIG. 8 is a view illustrating a method of plating a circuit pattern on an upper surface and an electrode on a lower surface twice using secondary and tertiary metals and attaching a circuit element to a substrate on which plating is completed.

At least one through hole 34 for electrically connecting the circuit pattern of the upper surface and the electrode of the lower surface is formed in the substrate 40 prepared for manufacturing the wire-bonded printed circuit board. When the through hole 34 is formed, the conductive material is filled in the formed through hole 34.

After the formation of the through hole 34 is completed, as shown in (b), the primary circuit pattern 41a and the primary electrode 41b are formed by using a primary metal such as copper. At this time, the plating bridge 42a and the connection bridge for electrically connecting the circuit pattern blocks are formed together. At this time, the primary circuit pattern 41a and the primary electrode 41b are kept electrically connected by the pre-formed through hole 34.

When the primary circuit pattern 41a and the primary metal 41 for the primary electrode 41b are attached to the substrate 40, the secondary metal material 43 on the primary metal material as shown in (c). Is plated. To this end, a potential for plating from the outside is applied to the primary metal material by the connecting bridge. The process of plating the secondary metal material 43 is similarly applied to the plating bridge, and the secondary metal material is also plated on the plating bridge 42a to form the secondary plating bridge 42b. In this case, in the case of using nickel as the secondary metal material, the thickness of the nickel plated is in the range of 0.1 micrometers to several tens of micrometers, and preferably has a thickness within 1 to 10 micrometers. In addition, the plating thickness of gold also has a range of 0.005 micrometers to 10 micrometers, and preferably plated to a thickness of 0.01 to 1 micrometer. The thickness of the plating is determined in consideration of the conduction characteristics of the signal and the manufacturing cost. Even if nickel is plated beyond the suggested range, the plating efficiency of gold is not greatly improved and the manufacturing cost is increased. Similarly, when gold is plated too thin, the conduction properties are lowered, and when the thickness is thicker than the range, it is preferable to determine the thickness of the plating within the ranges given because the manufacturing cost is much increased compared to the conduction properties.

When the secondary metal is plated, the tertiary metal material 44 is plated on the secondary metal material as in (d). At this time, the third plating material is also plated on the plating bridge 42 to form the third plating bridge.

When the plating is completed, the connecting bridge and the plating bridge are removed by an etching method such as laser trimming. When the plated bridge is removed, the circuit element 45 is attached to the space between the circuit patterns or the circuit pattern as shown in (e). In this case, the circuit element 45 is attached to the substrate 40 in such a manner that the terminal portion 46 is exposed as described above.

When the circuit device 45 is fixed to the substrate, as shown in (f), the terminal portion 46 and the circuit pattern 49 are connected using the wire 47. When the terminal portion 46 and the circuit pattern 49 are connected by the wire 47, an insulating material is coated to surround the circuit element 45, the wire 47, and the circuit pattern 49 as in (g). . The coated insulating material is cured by passage of time, ultraviolet irradiation, or the like, and serves as a capsule to protect and insulate the circuit element 45, the wire 47, and the circuit pattern 49.

The manufacturing method described with reference to FIG. 8 is just an example, and the order and etching method may be modified through various methods.

As described above, the printed circuit board of the present invention connects the device and the printed circuit board by using a wire bonding method, thereby improving production yield and reducing defective rate. In addition, in order to use such a wire bonding method, the present invention provides a method in which wire bonding may be performed more efficiently by soft plating a pattern of a printed circuit board. In addition, by providing a plating method suitable for the electret condenser microphone provides a method that can be easily performed electrolytic soft plating.

Therefore, the electret condenser microphone having the wire-bonded printed circuit board and the manufacturing method thereof according to the present invention can reduce the manufacturing cost by not using an expensive SMD, and a defect occurs due to breakage of the SMD due to reflow over. The cause can be replaced by wire bonding to improve the yield.

In addition, an electret condenser microphone having a wire bonded printed circuit board and a method of manufacturing the same according to the present invention provide a material, thickness and plating method of a circuit pattern metal suitable for wire bonding, and facilitate plating of a circuit pattern. By providing a plating bridge and a connecting bridge which can be made, it is possible to manufacture and use a wire bonded printed circuit board more easily and inexpensively.

In addition, the electret condenser microphone having the wire-bonded printed circuit board and the manufacturing method thereof according to the present invention specifically provide a procedure for manufacturing the electret condenser microphone, and present a method of simultaneously plating a circuit pattern and an electrode, It makes the process simpler and cheaper.

Claims (13)

A case; An electret, a diaphragm, a bipolar plate, a spacer, a first base ring and a second base ring housed in the case; At least one circuit element for amplifying and filtering the electrical signals from the diaphragm and the bipolar plate, and a circuit pattern for providing a conductive path to the circuit element, wherein the circuit element and the circuit pattern are wire bonded. It is provided with a wire bonded printed circuit board, The circuit pattern is: A primary circuit pattern formed on the printed circuit board by being divided into one or more blocks by using a primary metal; A plating bridge for electrically connecting the block; A secondary circuit pattern formed by plating a secondary metal on the primary circuit pattern connected by the plating bridge; Consists of a tertiary circuit pattern formed by using a tertiary metal in the secondary circuit pattern, And the plating bridge is removed by a laser trimming method after the completion of the plating. The method of claim 1, The circuit device may be provided in the form of an integrated circuit or an ASIC including at least one of a capacitor and a field effect transistor. The electret condenser microphone having a wire bonded printed circuit board, wherein the material of the wire is gold. delete delete The method of claim 1, The wire bonded printed circuit board has one or more electrodes formed on a surface opposite to the surface on which the circuit pattern is formed. And the circuit pattern and the electrode are electrically connected by at least one through hole. In the manufacturing method of an electret condenser microphone having an electret, a diaphragm, a bipolar plate, a spacer, a first base ring and a second base ring, and a printed circuit board in which circuit elements and circuit patterns are connected by wire bonding. , Forming a primary circuit pattern divided into one or more blocks by using a primary metal on the substrate; Forming a plating bridge for electrically connecting the blocks; Plating a secondary metal on the primary circuit pattern connected by the plating bridge to form a secondary circuit pattern; Completing a circuit pattern by forming a tertiary circuit pattern using a tertiary metal on the secondary circuit pattern; Removing the plating bridge; Attaching circuit elements on the substrate from which the plating bridge is removed; Electrically connecting the circuit element with the completed circuit pattern by a wire; And wrapping the circuit pattern, the wire, and the circuit element with an insulating material. The method of claim 6, The primary metal is copper, the secondary metal is nickel, and the tertiary metal is gold. The method of claim 7, wherein The nickel is plated to a thickness of 0.1 to several tens of micrometers, preferably a method of manufacturing an electret microphone, characterized in that the plated to a thickness of 1 to 10 micrometers. The method of claim 7, wherein The gold is plated to a thickness of 0.05 to 10 micrometers, preferably a method for producing an electret microphone, characterized in that the plated to a thickness of 0.01 to 1 micrometer. The method of claim 6, The plating bridge is a manufacturing method of the electret microphone, characterized in that molded integrally with the primary circuit pattern. The method of claim 6, At least one of the step of forming the primary circuit pattern or the step of forming the secondary circuit pattern The manufacturing method of the electret microphone, characterized in that it further comprises the step of forming a connection bridge for connecting to an external power source. The method of claim 6, The plating method is an electrolytic soft plating method, characterized in that the electret microphone. The method of claim 6, Forming an electrode on the substrate surface on which the circuit pattern is not formed; Forming at least one through hole for electrically connecting the electrode and the circuit pattern; The method of claim 1, further comprising filling the through hole with a conductive metal material.

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