U.S. patent application number 15/509850 was filed with the patent office on 2017-09-14 for power inductor.
The applicant listed for this patent is MODA-INNOCHIPS CO., LTD.. Invention is credited to Seung Hun CHO, Jun Ho JUNG, Gyeong Tae KIM, Jung Gyu LEE, Ki Joung NAM, In Kil PARK.
Application Number | 20170263367 15/509850 |
Document ID | / |
Family ID | 55644843 |
Filed Date | 2017-09-14 |
United States Patent
Application |
20170263367 |
Kind Code |
A1 |
PARK; In Kil ; et
al. |
September 14, 2017 |
POWER INDUCTOR
Abstract
In accordance with an exemplary embodiment, a power inductor
includes a body, at least two bases disposed in the body, at least
two coil patterns disposed on the at least two bases, respectively,
and a connection electrode disposed on an outer portion of the body
and connecting the at least two coils to each other.
Inventors: |
PARK; In Kil; (Seongnam-Si,
Gyeonggi-Do, KR) ; KIM; Gyeong Tae; (Ansan-Si,
Gyeonggi-Do, KR) ; CHO; Seung Hun; (Siheung-Si,
Gyeonggi-Do, KR) ; JUNG; Jun Ho; (Siheung-Si,
Gyeonggi-Do, KR) ; NAM; Ki Joung; (Siheung-Si,
Gyeonggi-Do, KR) ; LEE; Jung Gyu; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MODA-INNOCHIPS CO., LTD. |
Ansan-Si, Gyeonggi-Do |
|
KR |
|
|
Family ID: |
55644843 |
Appl. No.: |
15/509850 |
Filed: |
April 27, 2015 |
PCT Filed: |
April 27, 2015 |
PCT NO: |
PCT/KR2015/004137 |
371 Date: |
March 8, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01F 17/04 20130101;
H01F 27/008 20130101; C08K 2003/282 20130101; B29C 43/02 20130101;
H01F 27/34 20130101; H05K 2201/1003 20130101; B22F 2301/35
20130101; B22F 1/0062 20130101; C08K 2201/01 20130101; B29L 2031/34
20130101; C08K 3/08 20130101; C08K 2003/222 20130101; B22F 2302/25
20130101; C08K 2201/001 20130101; B22F 3/02 20130101; B29C 65/002
20130101; H01F 41/10 20130101; B22F 1/02 20130101; H01F 41/0233
20130101; H01F 27/292 20130101; C23C 18/1653 20130101; H01F 41/041
20130101; C08K 3/04 20130101; C08K 2003/0856 20130101; C09K 5/14
20130101; H01F 2027/2809 20130101; H05K 1/181 20130101; B22F
2302/45 20130101; C23C 18/1637 20130101; C25D 7/123 20130101; H01F
2017/048 20130101; C08K 3/22 20130101; H01F 17/0013 20130101; H01F
27/22 20130101; C08K 3/28 20130101 |
International
Class: |
H01F 27/00 20060101
H01F027/00; H01F 27/29 20060101 H01F027/29; H01F 27/255 20060101
H01F027/255; H01F 27/28 20060101 H01F027/28 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 11, 2014 |
KR |
10-2014-0120128 |
Mar 9, 2015 |
KR |
10-2015-0032403 |
Claims
1. A power inductor, comprising: a body; at least two base disposed
in the body; at least two coil patterns disposed on the at least
two the base, respectively; and at least two external electrodes
respectively connected to the at least two coils, the at least two
external electrodes being disposed on an outer portion of the
body.
2. The power inductor of claim 1, wherein the body comprises metal
powder, a polymer, and a thermal conductive filler.
3. The power inductor of claim 2, wherein the metal powder
comprises metal alloy powder comprising iron.
4. The power inductor of claim 3, wherein the metal powder has a
surface that is coated with at least one of a magnetic material and
an insulation material.
5. The power inductor of claim 2, wherein the thermal conductive
filler comprises at least one selected from the group consisting of
MgO, AlN, and a carbon-based material.
6. The power inductor of claim 5, wherein the thermal conductive
filler is contained in a content of approximately 0.5 wt % to
approximately 3 wt %, based on approximately 100 wt % of the metal
powder.
7. The power inductor of claim 6, wherein the thermal conductive
filler has a size of approximately 0.5 gm to approximately 100
gm.
8. The power inductor of claim 1, wherein the base is formed by
bonding a copper foil to both surfaces of a metal plate comprising
iron.
9. The power inductor of claim 1, wherein the plurality of external
electrodes are spaced apart from each other on the same side
surface of the body or disposed on side surfaces of the body, which
are different from each other.
10. The power inductor of claim 1, further comprising a magnetic
layer disposed on at least one area of the body.
11. The power inductor of claim 10, wherein the magnetic layer has
magnetic permeability higher than that of the body.
12. The power inductor of claim 11, wherein the magnetic layer
comprises the thermal conductive filler.
Description
BACKGROUND
[0001] The present disclosure relates to a power inductor, and more
particularly, to a power inductor that is capable of increasing a
capacity thereof.
[0002] A power inductor is generally provided on a power circuit
such as a DC-DC converter provided in portable devices. The power
inductor is being increasingly used instead of an existing wound
type choke coil pattern due to the tendency toward the high
frequency and miniaturization of the power circuit. Also, the power
inductor is being developed for miniaturization, high current, and
low resistance as small-sized and multifunctional portable devices
are required.
[0003] The power inductor may be manufactured in the form of a
stacked body in which ceramic sheets formed of a plurality of
ferrites or a low-k dielectric are stacked. Here, a metal pattern
is form in a coil pattern shape on each of the ceramic sheets. The
coil patterns formed on the ceramic sheets are connected to each
other by a conductive via formed on each of the ceramic sheets and
have a structure in which the coil patterns overlap each other in a
vertical direction in which the sheets are stacked. Typically, a
body of the power inductor is manufactured by using a magnetic
material including a quaternary system of nickel, zinc, copper, and
iron.
[0004] However, since the magnetic material has a saturation
magnetization less than that of a metal material, it may be
difficult to realize high current characteristics that are recently
required for portable devices. Thus, since the body of the power
inductor is formed of metal powder, the saturation magnetization
may increase in comparison with a case in which the body is formed
of a magnetic material. However, when the body is formed of a
metal, a loss of material may increase due to an increase in loss
of eddy current and hysteria in a high frequency. To reduce the
loss of the material, a structure in which the metal powder is
insulated from each other by using a polymer is being applied.
[0005] However, the power inductor including the body formed of the
metal powder and the polymer may decrease in inductance due to an
increase in temperature. That is, the power inductor increases in
temperature by heat generated from portable devices to which the
power inductor is applied. As a result, while the metal power
forming the body of the power inductor is heated, the inductance
may decrease.
[0006] Also, the power inductor includes one substrate provided in
the body and coil patterns formed on both surfaces of the
substrate, to prevent a capacity thereof from increasing.
PRIOR ART DOCUMENTS
[0007] KR Patent Publication No. 2007-0032259
SUMMARY
[0008] The present disclosure provides a power inductor which is
capable of improving thermal stability to prevent inductance from
decreasing.
[0009] The present disclosure also provides a power inductor which
is capable of improving a capacity.
[0010] The present disclosure also provides a power inductor which
is capable of improving magnetic permeability.
[0011] In accordance with an exemplary embodiment, a power inductor
includes: a body; at least two bases disposed in the body; at least
two coil patterns disposed on the at least two the base,
respectively; and at least two external electrodes respectively
connected to the at least two coils, the at least two external
electrodes being disposed on an outer portion of the body.
[0012] The body may include metal powder, a polymer, and a thermal
conductive filler.
[0013] The metal powder may include metal alloy powder including
iron.
[0014] The thermal conductive filler may include at least one
selected from the group consisting of MgO, AlN, and a carbon-based
material.
[0015] The thermal conductive may be contained in a content of
approximately 0.5 wt % to approximately 3 wt %, based on
approximately 100 wt % of the metal powder.
[0016] The thermal conductive filler may have a size of
approximately 0.5 .mu.m to approximately 100 on.
[0017] The base may be formed by bonding a copper foil to both
surfaces of a metal plate comprising iron.
[0018] The plurality of external electrodes may be spaced apart
from each other on the same side surface of the body or disposed on
side surfaces of the body, which are different from each other.
[0019] The power inductor may further include a magnetic layer
disposed on at least one area of the body.
[0020] The magnetic layer may have magnetic permeability higher
than that of the body.
[0021] The magnetic layer may include the thermal conductive
filler.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Exemplary embodiments can be understood in more detail from
the following description taken in conjunction with the
accompanying drawings, in which:
[0023] FIG. 1 is a perspective view of a power inductor in
accordance with an exemplary embodiment;
[0024] FIGS. 2 and 3 are cross-sectional views taken along lines
A-A' and B-B' of FIG. 1, respectively;
[0025] FIG. 4 is a cross-sectional view of a power inductor in
accordance with another exemplary embodiment;
[0026] FIGS. 5 to 7 are cross-sectional views of a power inductor
in accordance with other exemplary embodiments; and
[0027] FIGS. 8 through 10 are cross-sectional views illustrating a
method for manufacturing a power inductor in accordance with an
exemplary embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0028] Hereinafter, specific embodiments will be described in
detail with reference to the accompanying drawings. The present
disclosure 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
concept of the invention to those skilled in the art.
[0029] FIG. 1 is a perspective view of a power inductor in
accordance with an exemplary embodiment, FIG. 2 is a
cross-sectional view taken along line A-A' of FIG. 1, and FIG. 3 is
a cross-sectional view taken along line B-B' of FIG. 2.
[0030] Referring to FIGS. 1 to 3, the power inductor in accordance
with an exemplary embodiment may include a body 100, at least two
bases 200 (210 and 220) disposed in the body 100, coil patterns 300
(310, 320, 330, and 340) formed on at least one surface of each of
at least two base 200, first external electrodes 400 (410 and 420)
disposed on two opposite side surfaces of the body 100 and
connected to the coil patterns 310 and 320, respectively; and
second external electrodes 500 (510 and 520) disposed on the two
opposite side surfaces of the body 100, spaced apart from the first
external electrodes 410 and 420, and respectively connected to the
coil patterns 330 and 340. That is, the coil patterns 300
respectively disposed on at least two bases 200 are connected by
the external electrodes 400 and 500 different from each other to
realize at least two power inductors in the body 100.
[0031] The body 100 may have, for example, a hexahedral shape. The
body 100, however, may have a polyhedral shape in addition to the
hexahedral shape. The body 100 may further include metal powder
110, a polymer 120, and a thermal conductive filler 130. That is,
the body 100 may be formed of the metal powder 110, the polymer
120, and the thermal conductive filler 130. The metal powder 110
may have a mean particle diameter of approximately 1 .mu.m to
approximately 50 .mu.m. Also, the metal powder 110 may use a single
kind of particles or at least two kinds of particles having the
same size and a single kind of particles or at least two kinds of
particles having a plurality of sizes. For example, a first metal
particle having a mean size of approximately 30 .mu.m and a second
metal particle having a mean size of approximately 30 .mu.m may be
mixed with each other for using. When at least two kinds of metal
powder 110 having sizes different from each other are used, the
body 100 may increase in filling rate to maximize capacity. For
example, when metal powder having a size of approximately 30 .mu.m
is used, a pore may be generated between the metal powder having
the size of approximately 30 .mu.m, resulting in decreasing the
filling rate. However, since metal power having a size of
approximately 30 .mu.m is mixed between the metal power having the
size of approximately 30 .mu.m, the filling rate may further
increase. The metal powder 110 may use a metal material including
iron (Fe). For example, the metal powder 110 may include at least
one metal selected from the group consisting of iron-nickel
(Fe-Ni), iron-nickel-silica (Fe-Ni-Si), iron-aluminum-silica
(Fe-Al-Si), and iron-aluminum-chrome (Fe-Al-Cr). That is, since the
metal powder 110 includes the iron, the metal powder 110 may be
formed as a metal alloy having a magnetic structure or magnetic
property to have predetermined magnetic permeability. Also, surface
of the metal powder 110 may be coated with a magnetic material
having magnetic permeability different from that of the metal
powder 110. For example, the magnetic material may be formed of a
metal oxide magnetic material. That is, the magnetic material may
be formed of at least one oxide magnetic material selected from the
group consisting of a nickel-oxide magnetic material, a zinc-oxide
magnetic material, a copper-oxide magnetic material, a
manganese-oxide magnetic material, a cobalt-oxide magnetic
material, a barium-oxide magnetic material, and a
nickel-zinc-copper oxide magnetic material. The magnetic material
applied on the surface of the metal powder 110 may be formed of a
metal oxide including iron and have a magnetic permeability greater
than that of the metal powder 110. Furthermore, the surface of the
metal powder 110 may be coated with at least one insulating
material. For example, the surface of the metal powder 110 may be
coated with an oxide and an insulating polymer such as parylene.
The oxide may be formed by oxidizing the metal powder 110 or be
coated with one selected from the group consisting of TiO2, SiO2,
ZrO2, SnO2, NiO, ZnO, CuO, CoO, MnO, MgO, Al2O3, Cr2O3, Fe2O3,
B2O3, and Bi2O3. Also, the surface of the metal powder 110 may be
coated by using various insulating polymer materials in addition to
the parylene. Here, the metal powder 110 may be coated with oxide
having a double-layered structure or a double-layered structure of
oxide and polymer materials. Alternatively, the surface of the
metal powder 110 may be coated with the magnetic material and then
the insulating material. As described above, the surface of the
metal powder 110 may be coated with the insulating material to
prevent a short-circuit due to the contact of the metal powder 110
from occurring. The polymer 120 may be mixed with the metal powder
110 so that the metal powder 110 is insulated with each other. That
is, the metal powder 110 may increase in loss of eddy current and
hysteria in a high frequency to cause a loss of the material. To
reduce the loss of the material, the polymer 120 may be provided to
insulate the metal powder 110 from each other. Although the polymer
120 is selected from the group consisting of epoxy, polyimide, and
a liquid crystalline polymer (LCP), the present disclosure is not
limited thereto. The polymer 120 may include a thermosetting resin
to give an insulation property to the metal powder 110. The
thermosetting resin may include at least one selected from the
group consisting of a novolac epoxy resin, a phenoxy type epoxy
resin, a BPA type epoxy resin, a BPF type epoxy resin, a
hydrogenated BPA epoxy resin, a dimer acid modified epoxy resin, a
urethane modified epoxy resin, a rubber modified epoxy resin, and a
DCPD type epoxy resin. Here, the polymer 120 may be contained in a
content of approximately 2.0 wt % to approximately 5.0 wt %, based
on 100 wt % of the metal powder. When the polymer 120 increases in
content, a volume fraction of the metal powder 110 may decrease,
and thus, it may be difficult to properly realize an effect for
increasing the saturation magnetization, and the magnetic
characteristics of the body 100, i.e., the magnetic permeability
may decreases. When the polymer 120 decreases in content, a strong
acid or strong alkaline solution used in a process for
manufacturing the inductor may be permeated into the inductor to
reduce the inductance characteristics. Thus, the polymer 120 may be
contained within a range in which the saturation magnetization and
inductance of the metal powder 110 do not decrease. Also, the
thermal conductive filler 130 may be provided to solve the
limitation in which the body 100 is heated by the external heat.
That is, when the metal powder 110 of the body 100 is heated by the
external heat, the thermal conductive filler 130 may release the
heat of the metal powder 110 to the outside. Although the thermal
conductive filler 130 includes at least one selected from the group
consisting of MgO, AlN, and a carbon-based material, the present
disclosure is not limited thereto. Here, the carbon-based material
may include carbon and have various shapes. For example, the
carbon-based material may include graphite, carbon black, graphene,
graphite, and the like. Also, the thermal conductive filler 130 may
be contained in a content of approximately 0.5 wt % to
approximately 3 wt %, based on approximately 100 wt % of the metal
powder 110. When the content of the thermal conductive filler 130
is below the above-described range, a heat dissipation effect may
not be achieved. On the other hand, when the content of the thermal
conductive filler 130 is above the above-described range, the
magnetic permeability of the metal powder 110 may decrease. Also,
the thermal conductive filler 130 may have, for example, a size of
approximately 0.5 gm to approximately 100 .mu.m. That is, the
thermal conductive filler 130 may have a size greater or less than
that of the metal powder 110. On the other hand, the body 100 may
be manufactured by stacking a plurality of sheets formed of a
material including the metal powder 110, the polymer 120, and the
thermal conductive filler 130. Here, when the body 100 is
manufactured by stacking the plurality of sheets, the thermal
conductive fillers 130 in the sheets may have contents different
from each other. For example, the more thermal filters are away
from the base 200 upward and downward, the content of the thermal
conductive fillers 130 in the sheets may gradually increase in
content. Also, as necessary, the body 100 may be formed by applying
various processes such as a process of printing paste formed of a
material including the metal powder 110, the polymer 120, and the
thermal conductive filler 130 at a predetermined thickness or a
process of filling the paste into a frame to compress the paste.
Here, the number of sheets stacked for forming the body 100 or a
thickness of the paste printed at the predetermined thickness may
be determined to adequate number or thickness in consideration of
electrical characteristics such as the inductance required for the
power inductor.
[0032] At least two bases 200 (210 and 220) may be provided in the
body 100. For example, at least two bases 200 may be provided in
the body 100 in a longitudinal direction of the body 100 and spaced
a predetermined distance in a direction of a thickness of the body
100. The base 200, for example, may be formed of copper clad
lamination (CCL), a metal magnetic material, or the like. Here, the
base 200 is formed of the magnetic material to improve the magnetic
permeability and easily realize the capacity. That is, the CCL is
manufactured by bonding a copper foil to glass reinforced fiber.
Thus, the CCL may not have the magnetic permeability to reduce the
magnetic permeability of the power inductor.
[0033] However, when the metal magnetic material is used as the
base 200, the magnetic permeability of the power inductor may not
be reduced because the metal magnetic material has the magnetic
permeability. The base 200 using the metal magnetic material may be
manufactured by bonding the copper foil to a plate that has a
predetermined thickness and is formed of at least one metal
selected from the group consisting of metal including iron such as,
for example, iron-nickel (Fe-Ni), iron-nickel-silica (Fe-Ni-Si),
iron-aluminum-silica (Fe-Al-Si), and iron-aluminum-chrome
(Fe-Al-Cr). That is, an alloy formed of at least one metal
including iron may be manufactured in the form of a plate having a
predetermined thickness, and then the copper foil may be bonded to
at least one surface of the metal plate to manufacture the base
200. Also, at least one conductive via (not shown) may be formed in
a predetermined area of the base 200, and the coil patterns 310 and
320 respectively disposed on the upper and lower portions of the
base 200 may be electrically connected to each other by the
conductive via. The via (not shown) passing in a direction of a
thickness of the base 200 may be formed, and then the conductive
paste may be filled into the via to form the conductive via.
[0034] The coil patterns 300 (310, 320, 330, and 340) may be
disposed on at least one surface, preferably, both surfaces of each
of the at least two bases 200. The coil patterns 310 and 320 may be
disposed on each of upper and lower portions of the first base 210
and electrically connected by the conductive via formed on the
first base. Similarly, the coil patterns 330 and 340 may be
disposed on upper and lower portions of the second base 220 and
electrically connected by the conductive via formed on a second
base. Here, the coil patterns 310 and 330 and the coil patterns 320
and 340 may be exposed in directions opposite to each other. The
plurality of coil patterns 300 may be disposed on a predetermined
area of the base 200, e.g., disposed outward from a central portion
thereof in a spiral shape, and the two coil patterns disposed on
the base 200 may be connected to form one coil. That is, at least
two coils may be provided in one body 100. Here, the coil patterns
310 and 330 on the upper portion and the coil pattern 320 and 340
on the lower portion may have the same shape. Also, the plurality
of coil patterns 300 may overlap each other. Alternatively, coil
pattern 320 and 340 on the lower portion may overlap each other on
an area in which the coil pattern 310 and 330 on the upper portion
is not formed. Here, although the coil pattern 310 on the first
base 210 and the coil pattern 330 on the second base 220 are
exposed in the same direction, the coil patterns 310 and 330 may
not overlap each other and be spaced a predetermined distance from
each other. Similarly, although the coil pattern 320 on the first
base 210 and the coil pattern 340 on the second base 220 are
exposed in the same direction, the coil patterns 320 and the 340
may not overlap each other and be spaced a predetermined distance
from each other. Accordingly, the coil patterns 310 and 320 on the
first base 210 and the coil patterns 330 and 340 on the second base
220 may be connected by the first and second external electrodes
400 and 500, respectively. The coil patterns 300 and 320 may be
formed by a method such as, for example, screen printing, coating,
deposition, plating, or sputtering. Although each of the plurality
of coil patterns 300 and the conductive via is formed of a material
including at least one of silver (Ag), cooper (Cu), and copper
alloy, the present disclosure is not limited thereto. On the other
hand, when the plurality of coil patterns 300 are formed through
the plating process, the metal layer, for example, a copper layer
may be formed on the base 200 by the plating process and then be
patterned by a lithography process. That is, the copper layer may
be formed by using the copper foil formed on a surface of the base
200 as a seed layer through the plating process and then be
patterned to form the coil patterns 300. Alternatively, a
photosensitive film pattern having a predetermined shape may be
formed on the base 200, and the plating process may be performed to
grow the metal layer from the exposed surface of the base 200, and
then the photosensitive film may be removed to form the coil
patterns 310 and 320 having a predetermined shape. Alternatively,
the coil patterns 300 may be formed in a multi-layered shape. That
is, a plurality of coil patterns may be further formed upward from
the coil patterns 310 formed on the upper portion of the first base
210, and a plurality of coil patterns may be further formed
downward from the coil patterns 320 formed on the lower portion of
the second base 220. When the plurality of coil patterns 300 are
formed in the multi-layered shape, an insulation layer may be
formed between lower and upper layers, and a conductive via (not
shown) may be formed in the insulation layer to connect the
multi-layered coil patterns to each other.
[0035] First external electrodes 400 (410 and 420) may be formed on
both ends of the body 100, respectively. For example, the external
electrodes 400 may be formed on both side surfaces facing each
other in the longitudinal direction of the body 100. The first
external electrodes 410 and 420 may be electrically connected to
the coil patterns 310 and 320 formed on the first base 210. That
is, at least one end of the plurality of coil patterns 310 and 320
may be exposed to the outside of the body 100 in directions
opposite to each other, and the first external electrodes 410 and
420 may be connected to the exposed ends of the coil patterns 300.
The above-described first external electrodes 410 and 420 may be
formed on both ends of the body 100 by dipping the body 100 into
the conductive paste or through the various processes such as the
printing, the deposition, and the sputtering and then be patterned.
The first external electrode 410 and 420 may be formed of an
electro-conductive metal that is selected from the group consisting
of gold, silver, platinum, copper, nickel, palladium, and an alloy
thereof. Also, a nickel plated layer (not shown) or a tin plated
layer (not shown) may be further formed on a surface of the first
external electrodes 410 and 420.
[0036] The second external electrodes 500 (510 and 520) may be
formed on both ends of the body 100 and spaced from the first
external electrodes 410 and 420. The first external electrodes 410
and 420 and the second external electrodes 510 and 520 may be
formed on the same side surface of the body 100 and spaced from
each other. The second external electrodes 510 and 520 may be
electrically connected to the coil patterns 330 and 340 formed on
the second base 220.
[0037] That is, at least one end of the coil patterns 330 and 340
may be exposed to the outside of the body in directions opposite to
each other, and the second external electrodes 510 and 520 may be
connected to the ends of the coil patterns 330 and 340. Although
the coil patterns 330 and 340 are exposed in the same direction as
the coil patterns 310 and 320, the coil patterns 330 and 340 and
the coil patterns 310 and 320 may not overlap each other and be
spaced a predetermined distance from each other. Thus, the coil
patterns 330, 340, 310, and 320 may be connected to the first and
second external electrodes 400 and 500, respectively. The second
external electrodes 510 and 520 may be formed through the same
process as that of the first external electrodes 410 and 420 at the
same time. That is, the second external electrodes 510 and 520 may
be formed on the both ends of the body 100 through various
processes including a process of dipping the body 100 into the
conductive paste, a printing process, a deposition process, and a
sputtering process and then be patterned. The second external
electrode 510 and 520 may be formed of electro-conductive metal
that is selected from the group consisting of gold, silver,
platinum, copper, nickel, palladium, and alloy thereof. Also, a
nickel plated layer (not shown) or a tin plated layer (not shown)
may be further formed on a surface of the first and second external
electrodes 410 and 420.
[0038] Alternatively, an insulation layer 600 may be further formed
between the plurality of coil patterns 300 and the body 100 to
insulate the plurality of coil patterns 300 from the metal powder
110. That is, the insulation layer 600 may be formed on the upper
and lower portions of the base 200 to cover the plurality of coil
patterns 300. The insulation layer 600 may include at least one
material selected from the group consisting of epoxy, polyimide,
and a liquid crystal crystalline polymer. That is, the insulation
layer 600 may be formed of the same material as the polymer 120
forming the body 100. Also, the insulation layer 600 may be formed
by applying an insulating polymer such as parylene on the coil
patterns 300. That is, the insulation layer 600 may be coated in a
uniform thickness along stepped portions of the coil patterns 300.
Alternatively, the insulation layer 600 may be formed on the coil
patterns 300 by using the insulation sheet.
[0039] As described above, in the power inductor in accordance with
an exemplary embodiment, the at least two bases 200 disposed in the
body 100, each of which has at least one surface on which the coil
pattern 300 is formed, may be provided to form the plurality of
coils in one body 100. Also, the coils may be connected to the
external electrodes 400 and 500 different from each other to
realize the plurality of power inductor in one body 100.
Accordingly, the power inductor may decrease in volume to reduce an
area that is occupied by the power inductor on an electric circuit.
Also, two power inductors may be realized in one body 100 to
increase the capacity of power inductor. The body 100 may include
the metal powder 110, the polymer 120, and the thermal conductive
filler 130. Accordingly, the heat of the body 100, which is
generated by heating of the metal powder 110, may be released to
the outside to prevent the body 100 from increasing in temperature,
and thus prevent the inductance from being reduced. Also, the base
200 inside the body 100 may be formed of the magnetic material to
prevent the power inductor from being reduced in magnetic
permeability.
[0040] FIG. 4 is a perspective view of a power inductor in
accordance with another exemplary embodiment. The first external
electrode 410 and 420 and the second external electrode 510 and 520
are formed in directions different from each other. That is, the
first external electrode 410 and 420 and the second external
electrode 510 and 520 may be disposed on side surfaces of the body
100, which are perpendicular to each other. For example, the first
external electrodes 410 and 420 may be disposed on both side
surfaces opposite to each other in a longitudinal direction of the
body 100, and the second external electrodes 510 and 520 may be
disposed on both side surfaces opposite to each other in a
transverse direction of the body 100
[0041] FIG. 5 is a cross-sectional view of a power inductor in
accordance with another exemplary embodiment.
[0042] Referring to FIG. 5, a power inductor in accordance with an
exemplary embodiment may further include a body 100, at least two
bases 200 (210 and 220) disposed in the body 100, coil patterns 300
(310, 320, 330, and 340) disposed on at least one surface of each
of at least two base 200, external electrodes 410 and 420 disposed
on outer portion of the body 100, a connection electrode 500
disposed on the outer portion of the body, spaced from the external
electrodes 410 and 420, and connected to at least one coil pattern
300 formed on each of at least two base 200 in the body, and at
least one of magnetic layers 710 and 720 disposed on the upper and
lower portions of the body 100, respectively. Also, the power
inductor may further include an insulation layer 500 provided on
each of the coil patterns 300.
[0043] The magnetic layer 700 (710 and 720) may be provided to at
least one area of the body 100. That is, a first magnetic layer 710
may be disposed on a top surface of the body 100, and a second
magnetic layer 720 may be disposed on a bottom surface of the body
100. Here, the first and second magnetic layers 710 and 720 may be
provided to increase magnetic permeability of the body 100 and
formed of a material having a magnetic permeability greater than
that of the body 100. For example, the body 100 may have magnetic
permeability of approximately 20, and each of the first and second
magnetic layers 710 and 720 may have magnetic permeability of
approximately 40 to approximately 1000. The first and second
magnetic layers 710 and 720 may be formed of, for example, magnetic
powder and a polymer. That is, the first and second magnetic layers
710 and 720 may be formed of a material having magnetism higher
than that of the magnetic material of the body 100 or have a
content of the magnetic material, which is higher than that of the
magnetic material of the body 100 so that each of the first and
second magnetic layers 710 and 720 has the magnetic permeability
higher than that of the body 100. Here, the polymer may be
contained in a content of approximately 15 wt %, based on
approximately 100 wt % of the metal powder. Also, the magnetic
material powder may use at least one selected from the group
consisting of a nickel magnetic material (Ni Ferrite), a zinc
magnetic material (Zn Ferrite), a copper magnetic material (Cu
Ferrite), a manganese magnetic material (Mn Ferrite), a cobalt
magnetic material (Co Ferrite), a barium magnetic material (Ba
Ferrite), and a nickel-zinc-copper magnetic material (Ni-Zn-Cu
Ferrite) or at least one oxide magnetic material thereof. That is,
the magnetic layer 700 may be formed by using a metal alloy powder
including iron or a metal alloy oxide including iron. Also, the
magnetic powder may be formed by applying the magnetic material to
the metal alloy powder. For example, the magnetic material powder
may be formed by applying at least one magnetic material oxide
selected from the group consisting of a nickel-oxide magnetic
material, a zinc-oxide magnetic material, a copper-oxide magnetic
material, a manganese-oxide magnetic material, a cobalt-oxide
magnetic material, a barium-oxide magnetic material, and a
nickel-zinc-copper oxide magnetic material to, for example, the
metal alloy powder including iron. That is, the magnetic material
powder may be formed by applying the metal oxide including iron to
the metal alloy powder. Alternatively, the magnetic material powder
may be formed by mixing at least one magnetic material oxide
selected from the group consisting of a nickel-oxide magnetic
material, a zinc-oxide magnetic material, a copper-oxide magnetic
material, a manganese-oxide magnetic material, a cobalt-oxide
magnetic material, a barium-oxide magnetic material, and a
nickel-zinc-copper oxide magnetic material with, for example, the
metal alloy powder including iron. That is, the magnetic material
powder may be formed by mixing the metal oxide including iron with
the metal alloy powder. On the other hand, each of the first and
second magnetic layers 710 and 720 may further include the thermal
conductive fillers in addition to the metal powder and polymer. The
thermal conductive fillers may be contained in a content of
approximately 0.5 wt % to approximately 3 wt %, based on
approximately 100 wt % of the metal powder. The first and second
magnetic layers 710 and 720 may be manufactured in a sheet shape
and respectively disposed on upper and lower portions of the body
100 on which a plurality of sheets are stacked. Also, the body 100
may be formed by printing a paste formed of a material including
metal powder 110, a polymer 120, and a thermal conductive filler
130 at a predetermined thickness or filling the paste into a frame
to compress the paste, and then the first and second magnetic
layers 710 and 720 may be respectively disposed on the upper and
lower portions of the body 100. Alternatively, the magnetic layer
710 and 720 may be formed by using the paste, i.e., formed by
applying the magnetic material to the upper and lower portions of
the body 100.
[0044] In accordance with another exemplary embodiment, a power
inductor may further include third and fourth magnetic layers 730
and 740 on upper and lower portions between a body 100 and at least
two bases 200 as illustrated in FIG. 6, and fifth and sixth
magnetic layers 750 and 760 may be further provided therebetween as
illustrated in FIG. 7. That is, at least one magnetic layer 700 may
be provided in the body 100. The magnetic layers 700 may be
manufactured in a sheet shape and provided in the body 100 in which
a plurality of sheets are stacked. That is, at least one magnetic
layer 700 may be provided between the plurality of sheets for
manufacturing the body 100. Also, when the body 100 is formed by
printing the paste formed of the material including the metal
powder 110, the polymer 120, and the thermal conductive filler 130
at a predetermined thickness, the magnetic layer may be formed
during the printing. Also, when the body 100 is formed by filling
the paste into the frame to compress the paste, the magnetic layer
may be inserted therebetween to compress the paste. Alternatively,
the magnetic layer 700 may be formed by using the paste, i.e.,
formed in the body 100 by applying a soft magnetic material during
the printing of the body 100.
[0045] FIGS. 8 through 10 are cross-sectional views sequentially
illustrating a method for manufacturing a power inductor in
accordance with an exemplary embodiment.
[0046] Referring to FIG. 8, at least two bases 210 and 220 are
provided, and the coil patterns 310, 320, 330, and 340 each of
which has a predetermined shape are formed on at least one surface,
preferably, both surfaces of each of the at least two bases 210 and
220. The bases 210 and 220 may be formed of CCL, a metal magnetic
material, or the like. For example, the bases 210 and 220 may be
formed of a metal magnetic material that is capable of improving
effective magnetism and easily realizing capacity. For example, the
bases 210 and 220 may be manufactured by bonding a copper foil to
both surfaces of a metal plate which is formed of a metal alloy
including iron and has a predetermined thickness. Also, the coil
patterns 310, 320, 330, and 340 may be formed on a predetermined
area of the bases 210 and 220, e.g., may be formed as a coil
pattern that is formed from a central portion thereof in a circular
spiral shape. Here, the coil pattern 310 and 330 may be formed on
one surface of the bases 210 and 220 , and then a conductive via
passing through a predetermined area of the bases 210 and 220 and
in which a conductive material is filled therein may be formed.
Also, the coil patterns 320 and 340 may be formed on the other
surface of the bases 210 and 220. The conductive via may be formed
by filling conductive paste into a via hole after the via hole is
formed in a thickness direction of the bases 210 and 220 by using
laser. For example, the coil patterns 310, 320, 330, and 340 may be
formed through a plating process. For this, a photosensitive
pattern having a predetermined shape may be formed on one surface
of the first base 210 to perform the plating process using a copper
foil as a seed on the first base 210. Then, a metal layer may be
grown from the exposed surface of the first base 210, and then the
photosensitive film may be removed. The coil patterns 320 may be
formed on the other surface of the first base 210 by using the same
manner as that for forming the coil pattern 310. Alternatively, the
coil patterns 330 and 340 may be formed on the both surfaces of the
second base 220 by using the same manner as that for forming the
coil pattern 310 and 320. Alternatively, the coil patterns 310,
320, 330, and 340 may be formed in a multi-layered shape. When the
coil patterns 310, 320, 330, and 340 are formed in the
multi-layered shape, an insulation layer may be formed between
lower and upper layers, and the conductive via (not shown) may be
formed in the insulation layer to connect the multi-layered coil
patterns to each other. The coil patterns 310, 320, 330, and 340
are formed on one surface and the other surface of the bases 210
and 220, respectively, and then the insulation layer 600 is formed
to cover the coil patterns 310, 320, 330, and 340. The insulation
layer 600 may be formed by closely attaching a sheet including at
least one material selected from the group consisting of epoxy,
polyimide, and a liquid crystal crystalline polymer to the coil
patterns 310, 320, 330, and 340.
[0047] Referring to FIG. 9, a plurality of sheets 100a to 100i
formed of a material including the metal powder 110 and the polymer
120 are provided. Here, the plurality of sheets 100a to 100i may be
formed of a material further including the thermal conductive
filler 130. Here, the metal powder 110 may use a metal material
including iron (Fe), and the polymer 120 may use epoxy, polyimide,
or the like, which is capable of insulating the metal powder 110
from each other. Also, the thermal conductive filler 130 may use
MgO, AlN, a carbon based material, or the like, which is capable of
releasing heat of the metal powder 110 to the outside. Also, the
surface of the metal powder 110 may be coated with a magnetic
material, for example, a metal oxide magnetic material. Here, the
polymer 120 may be contained in a content of approximately 2.0 wt %
to approximately 5.0 wt %, based on 100 wt % of the metal powder
110, and the thermal conductive filler 130 may be contained in a
content of approximately 0.5 wt % to approximately 3.0 wt %, based
on 100 wt % of the metal powder 110. The plurality of sheets 100a
to 100i are disposed on the upper and lower portions and
therebetween of at least two bases 210 and 220 on which the coil
patterns 310, 320, 330, and 340 are formed, respectively. For
example, at least one sheet 100a is disposed between at least two
bases 210 and 220, a plurality of sheets 100b to 100e are disposed
on an upper portion of the base 210, and a plurality of sheets 100f
to 100i are disposed on a lower portion of the base 220. Here, the
plurality of sheets 100a to 100i may have contents of thermal
conductive fillers 130, which are different from each other. For
example, the thermal conductive fillers 130 may have contents that
gradually increase from one surface and the other surface of the
base 200 toward the upper and lower sides of the base 200. That is,
the thermal conductive filters 130 of the sheets 100c and 100f
disposed on upper and lower portions of the sheets 100b and 100e
contacting the bases 210 and 220 may have contents higher than
those of the thermal conductive fillers 130 of the sheets 100b and
100e, and the thermal conductive fillers 130 of the sheets 100d and
100h disposed on upper and lower portions of the sheets 100c and
100f may have contents higher than those of the thermal conductive
fillers 130 of the sheets 100c and 100f. Like this, the contents of
the thermal conductive fillers 130 may gradually increase in a
direction that is away from the bases 210 and 220 to further
improve heat transfer efficiency.
[0048] Referring to FIG. 10, the plurality of sheets 100a to 100i
are stacked and compressed with the at least two bases 210 and 220
therebetween and then molded to form the body 100. The external
electrodes 400 may be formed so that the protruding portion of each
of the coil patterns 310, 320, 330 and 340 is electrically
connected to both ends of the body 100. The first and second
external electrodes 400 and 500 may be formed by various processes
including a process of dipping the body 100 into a conductive
paste, a process of printing the conductive past on both ends of
the body 10, a deposition process, and a sputtering process and be
patterned to be spaced apart from each other. Here, the conductive
paste may use a metal material that is capable of giving electric
conductivity to the first and second external electrodes 400 and
500. Also, a nickel plated layer and a tin plated layer may be
further formed on a surface of the first and second external
electrodes 400 and 500, if necessary.
[0049] In accordance with an exemplary embodiment, the at least two
bases each of which has at least one surface on which the coil
pattern having the coil shape is formed are provided in the body to
form the plurality of coils in one body, thereby increasing the
capacity of the power inductor.
[0050] Also, the coils disposed on the at least two bases in the
body are connected to the external electrodes different from each
other to realize the plurality of power inductor in one body.
Accordingly, the power inductor may decrease in volume to reduce an
area that is occupied by the power inductor.
[0051] Also, the body may include the metal powder, the polymer,
and the thermal conductive filler. Thus, the heat in the body,
which is generated by heating of the metal powder, may be released
to the outside to prevent the body from increasing in temperature,
thereby preventing a problem such as reduction in inductance.
[0052] Also, at least two bases may be formed of the magnetic
material to prevent the power inductor from being reduced in
magnetic permeability.
[0053] The power inductor may not be limited to the foregoing
embodiments, but be realized through various embodiments different
from each other. Therefore, it will be readily understood by those
skilled in the art that various modifications and changes can be
made thereto without departing from the spirit and scope of the
present invention defined by the appended claims.
* * * * *