Patent Application
20140176278
This application claims the priority of Korean Patent Application No. 10-2012-0152231 filed on Dec. 24, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an inductor and a manufacturing method thereof.
2. Description of the Related Art
As a high frequency filter removing high frequency noise emitted from digital devices such as computers, an inductor has been widely used. As such an inductor, there is a coil multilayer inductor. Meanwhile, in the coil multilayer inductor, a chip body is configured according to multilayered ceramic layers and coil conductors between the ceramic layers may be connected by using a through hole formed in the ceramic layers. In addition, after forming the coil as a looped curve, the initial end and the termination end of the coil are connected to an external electrode, respectively.
Meanwhile, high inductance and low resistance have been required in a high frequency filter. In general, inductance is proportional to the amount of turns of the coil and inversely proportional to a length thereof.
However, there may be a limitation in that the multilayered inductor may have a low self resonance frequency due to parasite capacitance generated by capacitive coupling between patterns of the initial end and the termination end.
Furthermore, since the multilayered inductor requires various constituent elements for connecting the coil and an external power source, a manufacturing yield may deteriorate and the multilayered inductor may be unsuitable for a mass production.
As a result, the development of technology capable of improving manufacturing yields of an inductor while improving the efficiency thereof is urgently required.
In Patent Document 1, the multilayered inductor is disclosed.
[Patent Document 1] Korean Patent Laid-Open Publication No. 2011-0094333
An aspect of the present invention provides an inductor having high inductance and a manufacturing method thereof.
Another aspect of the present invention also provides an inductor capable in which EMI noise due to leakage flux is reduced, and a manufacturing method thereof.
Another aspect of the present invention provides an inductor capable of improving a manufacturing yield and a manufacturing method thereof.
According to an aspect of the present invention, there is provided an inductor, including: a circuit board having an input and output terminal formed on a lower surface thereof, a connection pad formed on an upper surface thereof, and a via electrically connecting the input and output terminal and the connection pad; a coil having both ends joined to the connection pad and wound in a circular or a polygonal spiral shape in a longitudinal direction of the circuit board so as to have one or more turns; and a body stacked on the circuit board such that the coil and the connection pad are embedded therein.
A solder resist may be coated on an area of the connection pad except for a region in which the coil is joined thereto.
The both ends of the coil may have lead parts formed thereon, the lead parts being joined to the connection pad and being extended such that the coil is spaced apart from the circuit board by a predetermined distance.
The body may be formed of one of a dielectric material, a magnetic material, and a complex including a dielectric or a magnetic powder.
The coil may have a wound portion disposed in a center of the body.
According to another aspect of the present invention, there is provided a manufacturing method of an inductor, the method including: preparing a substrate part including a plurality of unit circuit boards; installing a coil on each of the plurality of unit circuit boards; stacking a body on the substrate part such that the coil is embedded therein; curing the body; and integrally cutting the unit circuit board on which the coil is installed and the body to separate the plurality of respective unit circuit boards and the body into a plurality of inductors.
Each of the unit circuit board may have an input and output terminal formed on a lower surface thereof, a connection pad formed on an upper surface thereof, and a via electrically connecting the input and output terminal and the connection pad.
A solder resist may be coated on an area of the connection pad except for a region in which the coil is joined thereto.
The coil may be wound to have a circular or polygonal spiral shape in a longitudinal direction of the circuit board.
The stacking of the body may be performed by fixing the substrate part having the coil installed thereon to a mold and then, filling the mold with one of a dielectric material, a magnetic material, and a complex including a dielectric or a magnetic powder.
The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements.
Referring to
The circuit board 120 maybe formed as a resin substrate formed of glass epoxy resin or the like, and may include an input and output terminal 122, a connection pad 124, and a via 126.
The input and output terminal 122 is formed on a lower surface of the circuit board 120 and may be electrically connected to an external power source when being installed in an electronic device or the like. That is, the input and output terminal 122 may include an input terminal 122a and an output terminal 122b.
Meanwhile, the input terminal 122a and the output terminal 122b may be formed at ends of the circuit board 120 in a longitudinal direction of the circuit board 120. That is, the input terminal 122a and the output terminal 122b may be spaced apart from each other so as to suppress the generation of short circuits.
However, in the embodiment, a case in which the input terminal 122a and the output terminal 122b are formed at both ends of the circuit board 120 in the longitudinal direction is described as an example, but is not limited thereto.
Here, when first defining terms for directions, the longitudinal direction of the circuit board 120 refers to an X direction in
The connection pad 124 may be formed on an upper surface of the circuit board 120, and may be disposed in a position corresponding to the input and output terminal 122. In addition, the connection pad 124 may include an input connection pad 124a connected to the input terminal 122a and an output connection pad 124b connected to the output terminal 122b.
That is, the connection pad 124 may be formed at ends on the upper surface of the circuit board 120 in the longitudinal direction of the circuit board 120.
Meanwhile, a solder resist 128 may be coated on the connection pad 124. That is, the solder resist 128 may be coated on an area of the connection pad 124, except for a region thereof in which the coil 140 of the connection pad 124 is joined thereto.
The via 126 serves to electrically connect the input and output terminal 122 and the connection pad 124 and may be formed in the thickness direction of the circuit board 120. In addition, the via 126 is disposed within the circuit board 120 so as not to be exposed outside thereof.
Both ends of the coil 140 are joined to the connection pad 124, and the coil 140 may be wound to have a circular or polygonal spiral shape in the longitudinal direction of the circuit board 120.
Meanwhile, the coil 140 maybe formed as a metallic line formed of silver (Ag), copper (Cu), or an alloy thereof, and at the time of the manufacturing thereof, a coil part 130 (see
Further, lead parts 142, joined to the connection pad 124 and extended such that the coil 140 is spaced apart from the circuit board 120 by a predetermined distance, maybe formed on both ends of the coil 140.
The lead parts 142 may be vertically formed such that distal ends thereof are disposed in the thickness direction.
That is, the lead parts 142 may be joined to the connection pad 124 by welding or the like.
Meanwhile, in the drawings, a case in which the coil 140 has a circular spiral shape is illustrated as an example, but it is not limited thereto, and the coil 140 may have various spiral shapes such as a quadrangular spiral shape or the like.
In addition, since the lead parts 142 are formed to have a predetermined length in the thickness direction, the coil 140 may be spaced apart from the circuit board 120. Accordingly, a sufficient path for magnetic flux may be provided and loss of the magnetic flux may be reduced. As a result, since the coil 140 may be spaced apart from the circuit board 120 by a predetermined distance, to thereby acquire higher inductance and reduce electromagnetic interference (EMI) noise due to leakage flux.
Meanwhile, the wound portion of the coil 140 may be disposed in the center of the body 160. That is, the coil 140 may be disposed in the body 160 such that a center line of the coil 140 and a center line of the body 160 are adjacent to each other or coincide with each other.
The body 160 may be stacked on the circuit board 120 such that the coil 140 and the connection pad 124 are embedded therein. In addition, the body 160 may be formed of one of a dielectric material, a magnetic material, and a complex including a dielectric or a magnetic powder.
Meanwhile, the body 160 may be formed by a method of fixing the circuit board 120 on which the coil 140 is installed to a mold and then filling the mold with one of a dielectric material, a magnetic material, and a complex including a dielectric or a magnetic powder in slurry form having a predetermined viscosity.
Thereafter, the body 160 may be cured at a predetermined temperature.
As described above, according to the structure in which capacitances generated between adjacent wound parts due to the coil 140 having a spiral shape in the longitudinal direction of the circuit board 120 are connected in series, total equivalent parasitic capacitance is decreased, and as a result, a self resonance frequency (SRF) may be increased.
Furthermore, it is possible to acquire a higher degree of inductance by reducing leakage flux and reduce electromagnetic interference (EMI) noise due to leakage flux.
That is, referring to
Hereinafter, an inductor according to another embodiment of the present invention will be described with reference to the accompanying drawings. However, the same constituent elements as the constituent elements described above use the same reference numerals, and the detailed description thereof will be substituted for the description.
Referring to
Meanwhile, since the circuit board 120 and the body 160 have the same configuration as the circuit board 120 and the body 160 provided in the inductor 100 according to the aforementioned embodiment of the present invention, a detailed description thereof will be omitted.
Further, since the coil 240 has the same configuration as the coil 140 provided in the inductor 100 according to the aforementioned embodiment of the present invention except for lead parts 242, a detailed description thereof will be omitted and hereinafter, only the lead parts 242 will be described.
The lead parts 242 may be formed such that distal ends thereof are extended in the longitudinal direction. Accordingly, coupling force between the lead parts 242 and the connection pad 124 may be increased, and the coil 240 may be more stably installed on the circuit board 120.
In addition, referring to
Hereinafter, an inductor according to yet another embodiment of the present invention will be described with reference to the accompanying drawings. However, the same constituent elements as the constituent elements described above use the same reference numerals, and the detailed description thereof will be substituted for the description.
Referring to
Meanwhile, since the circuit board 120 and the body 160 have the same configuration as the circuit board 120 and the body 160 provided in the inductor 100 according to the foregoing embodiment of the present invention, herein, a detailed description will be omitted and substituted for the description.
Both ends of the coil 340 are joined to the connection pad 124, and the coil 140 may be wound to have a circular or polygonal spiral shape in the width direction of the circuit board 120. Meanwhile, since the coil 340 is wound in the width direction of the circuit board 120, an area of the body 160 disposed inside the coil 340 may be increased.
Accordingly, although the coil 340 is wound to have a small number of turns, high inductance may be implemented therein.
In other words, even in the case in which the coil 340 is wound to have a larger diameter, such that the coil 340 is wound to have the smaller number of turns, high inductance may be implemented therein.
Meanwhile, the amount of turns of the coil 340 has one or more turns and is not limited to the winding number (that is, amount of turns) of the coil 340. In other words, it is not limited to the winding number of the coil 340 illustrated in the drawings, and the winding number of the coil 340 may be increased or decreased.
Hereinafter, a manufacturing method of an inductor according to an embodiment of the present invention will be described with reference to the accompanying drawings.
First, referring to
The lead parts 142 may be curved once such that the distal ends thereof are disposed in the thickness direction, or may be formed such that the distal ends thereof are disposed in the longitudinal direction.
Meanwhile, the coil 140 may be wound to have a circular or polygonal spiral shape in the longitudinal direction of the circuit board 120.
Thereafter, as illustrated in
Next, as illustrated in
Next, the body 160 maybe cured. The curing of the body 160 may be performed by heat or ultraviolet light. However, it is not limited thereto, and the curing of the body 160 may be performed by various methods.
Next, as illustrated in
As described above, since the inductor 100 may be manufactured by mounting the coil 140 on the substrate part 110 to which the input and output terminal 122 and the connection pad 124 are electrically connected through the via 126, the inductor 100 maybe manufactured without a separate process for electrically connecting the input and output terminal 122 and the connection pad 124, and as a result, a manufacturing yield thereof may be improved.
Furthermore, the inductor 100 may be manufactured by a method of joining the plurality of coils on the unit circuit boards 120 of the substrate part 110, and as a result, a mass production may be achieved. As a result, it is possible to further improve the manufacturing yield.
As set forth above, according to embodiments of the invention, since a coil is disposed in the center of a body, EMI noise due to leakage flux can be reduced.
Further, higher inductance can be acquired by reducing parasite capacitance through a coil having a spiral shape in a longitudinal direction of the circuit board.
Furthermore, a manufacturing yield can be improved simultaneously with achieving mass production by manufacturing an inductor using a process of stacking the coil and the body on the substrate part including a plurality of unit circuit boards.
While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2012-0152231 | Dec 2012 | KR | national |
