U.S. patent application number 12/900226 was filed with the patent office on 2011-12-15 for hybrid heat-radiating substrate and method of manufacturing the same.
This patent application is currently assigned to SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Joon Seok CHAE, Seog Moon CHOI, Jung Eun KANG, Kwang Soo KIM, Chang Hyun LIM, Heung Soo PARK, Sung Keun PARK.
Application Number | 20110303440 12/900226 |
Document ID | / |
Family ID | 45095306 |
Filed Date | 2011-12-15 |
United States Patent
Application |
20110303440 |
Kind Code |
A1 |
LIM; Chang Hyun ; et
al. |
December 15, 2011 |
HYBRID HEAT-RADIATING SUBSTRATE AND METHOD OF MANUFACTURING THE
SAME
Abstract
Disclosed herein are a hybrid heat-radiating substrate including
a metal core layer; an oxide insulating core layer that is formed
in a thickness direction of the metal core layer to have a shape
where the oxide insulating core layer is integrally formed with the
metal core layer, an oxide insulating layer that is formed on one
surface or both surfaces of the metal core layer, and a circuit
layer that is configured to include first circuit patterns formed
on the oxide insulating core layer and second circuit patterns
formed on the oxide insulating layer, and a method of manufacturing
the same.
Inventors: |
LIM; Chang Hyun; (Seoul,
KR) ; KANG; Jung Eun; (Gyunggi-do, KR) ; PARK;
Heung Soo; (Seoul, KR) ; CHOI; Seog Moon;
(Seoul, KR) ; KIM; Kwang Soo; (Gyunggi-do, KR)
; CHAE; Joon Seok; (Gyunggi-do, KR) ; PARK; Sung
Keun; (Gyunggi-do, KR) |
Assignee: |
SAMSUNG ELECTRO-MECHANICS CO.,
LTD.
Gyunggi-do
KR
|
Family ID: |
45095306 |
Appl. No.: |
12/900226 |
Filed: |
October 7, 2010 |
Current U.S.
Class: |
174/255 ;
156/150; 205/199 |
Current CPC
Class: |
H05K 3/44 20130101; H05K
3/108 20130101; H05K 2201/062 20130101; H05K 2201/09745 20130101;
H05K 1/053 20130101; Y10T 29/4913 20150115; H05K 2203/0315
20130101; H05K 3/10 20130101; H05K 3/445 20130101; H05K 1/0203
20130101; H05K 2201/10166 20130101 |
Class at
Publication: |
174/255 ;
205/199; 156/150 |
International
Class: |
H05K 1/03 20060101
H05K001/03; H05K 3/44 20060101 H05K003/44; C23C 28/00 20060101
C23C028/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 15, 2010 |
KR |
10-2010-0056616 |
Claims
1. A hybrid heat-radiating substrate, comprising: a metal core
layer; an oxide insulating core layer that is formed in a thickness
direction of the metal core layer to have a shape where the oxide
insulating core layer is integral formed with the metal core layer;
an oxide insulating layer that is formed on one surface or both
surfaces of the metal core layer; and a circuit layer that is
configured to include first circuit patterns formed on the oxide
insulating core layer and second circuit patterns formed on the
oxide insulating layer.
2. The hybrid heat-radiating substrate as set forth in claim 1,
wherein one side or two adjacent sides of the oxide insulating core
layer are exposed to the outside.
3. The hybrid heat-radiating substrate as set forth in claim 1,
further comprising a protective layer formed on the circuit
layer.
4. The hybrid heat-radiating substrate as set forth in claim 1,
wherein the first circuit pattern is mounted with thermally
weakened elements and the second circuit pattern is mounted with
heat generating elements.
5. The hybrid heat-radiating substrate as set forth in claim 1,
wherein the metal core layer is made of aluminum and the oxide
insulating core layer and the oxide insulating layer are made of
alumina.
6. The hybrid heat-radiating substrate as set forth in claim 1,
wherein the second circuit patterns are formed on both surfaces of
the metal core layer and are connected to each other through a
via.
7. The hybrid heat-radiating substrate as set forth in claim 1,
wherein the oxide insulating core layer is formed on both surfaces
of the metal core layer.
8. A method of manufacturing a hybrid heat-radiating substrate,
comprising: providing a metal core member; forming an oxide
insulating core layer by performing volume anodizing on the metal
core member in a thickness direction; forming an oxide insulating
layer by performing surface anodizing on one surface or both
surfaces of the metal core member; and forming a circuit layer that
is configured to include first circuit patterns positioned on the
oxide insulating core layer and second circuit patterns positioned
on the oxide insulating layer.
9. The method of manufacturing a hybrid heat-radiating substrate as
set forth in claim 8, further comprising after the forming the
circuit layer, forming a protective layer covering the circuit
layer.
10. The method of manufacturing a hybrid heat-radiating substrate
as set forth in claim 9, further comprising after the forming the
protective layer, mounting thermally weakened elements on the first
circuit patterns formed on the oxide insulating core layer; and
mounting heat generating elements on the second circuit patterns
formed on the oxide insulating layer.
11. The method of manufacturing a hybrid heat-radiating substrate
as set forth in claim 8, further comprising forming a via
connecting the circuit layers formed on both surfaces of the metal
core member.
12. The method of manufacturing a hybrid heat-radiating substrate
as set forth in claim 11, wherein the forming the via is performed
by forming a through hole penetrating through the metal core member
after forming the oxide insulating core layer, forming an
insulating layer in an inner wall of the through hole at the
forming the oxide insulating layer, and forming the plating layer
in an inner wall of the insulating layer at the forming the circuit
layer.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 10-2010-0056616, filed on Jun. 15, 2010, entitled
"Hybrid Heat-Radiating Substrate and Method Of Manufacturing The
Same" which is hereby incorporated by reference in its entirety
into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to a hybrid heat-radiating
substrate and a method of manufacturing the same.
[0004] 2. Description of the Related Art
[0005] Recently, the use of multi-functional electronic devices has
expanded. Considering characteristics of these products, various
electronic components should be mounted on a single substrate.
Recently, a heat-radiating problem caused by heat generating
elements mounted on the substrate has been an issue. In order to
solve the heat-radiating from these heat generating elements,
various types of heat-radiating substrates using metal materials
with good thermal conductivity have been manufactured.
[0006] The heat-radiating substrate including an insulating layer
formed on a metal core layer and a circuit layer formed on the
insulating layer have been commercialized up to now. The
heat-radiating substrate has excellent heat-radiating property as
compared to a general organic PCB; however, it is difficult to
implement high density/integration of the heat-radiating
substrate.
[0007] In addition, when heat generating elements such as LED and
electronic components vulnerable to heat (hereinafter, thermally
weakened elements) are simultaneously mounted on a single
substrate, the above-mentioned heat-radiating substrate has high
thermal conductivity, such that heat generated from the heat
generating elements is transferred to the entire heat-radiating
substrate (in particular, through a metal core layer) and is also
transferred to an area where heat is not transferred, thereby
degrading the performance of the thermally weakened elements.
SUMMARY OF THE INVENTION
[0008] The present invention has been made in an effort to provide
a hybrid heat-radiating substrate including a metal core layer in
order to keep heat-radiating performance of heat generating
elements, an oxide insulating core layer having lower thermal
conductivity than the metal core layer that is integrally formed
with the metal core layer by volume anodizing, and thermally
weakened elements that is mounted on an oxide insulating core
layer, thereby making it possible to protect thermally weakened
elements even though heat generating elements and thermally
weakened elements are mounted on a single substrate together.
[0009] Further, the present invention proposes a method of
manufacturing the hybrid heat-radiating substrate.
[0010] A hybrid heat-radiating substrate according to an exemplary
embodiment of the present invention includes: a metal core layer;
an oxide insulating core layer that is formed in a thickness
direction of the metal core layer to have a shape where the oxide
insulating core layer is integrally formed with the metal core
layer; an oxide insulating layer that is formed on one surface or
both surfaces of the metal core layer; and a circuit layer that is
configured to include first circuit patterns formed on the oxide
insulating core layer and second circuit patterns formed on the
oxide insulating layer.
[0011] One side or two adjacent sides of the oxide insulating core
layer are exposed to the outside.
[0012] The hybrid heat-radiating substrate further includes a
protective layer formed on the circuit layer.
[0013] The first circuit pattern is mounted with thermally weakened
elements and the second circuit pattern is mounted with heat
generating elements.
[0014] The metal core layer is made of aluminum and the oxide
insulating core layer and the oxide insulating layer are made of
alumina.
[0015] The second circuit patterns are formed on both surfaces of
the metal core layer and are connected to each other through a
via.
[0016] The oxide insulating core layer is formed on both surfaces
of the metal core layer.
[0017] A method of manufacturing a hybrid heat-radiating substrate
according to an exemplary embodiment of the present invention
includes: providing a metal core member; forming an oxide
insulating core layer by performing volume anodizing on the metal
core member in a thickness direction; forming an oxide insulating
layer by performing surface anodizing on one surface or both
surfaces of the metal core member; and forming a circuit layer that
is configured to include first circuit patterns positioned on the
oxide insulating core layer and second circuit patterns positioned
on the oxide insulating layer.
[0018] The method of manufacturing a hybrid heat-radiating
substrate further includes after the forming the circuit layer,
forming a protective layer covering the circuit layer.
[0019] The method of manufacturing a hybrid heat-radiating
substrate further includes: after the forming the protective layer,
mounting thermally weakened elements on the first circuit patterns
formed on the oxide insulating core layer; and mounting heat
generating elements on the second circuit patterns formed on the
oxide insulating layer.
[0020] The method of manufacturing a hybrid heat-radiating
substrate further includes forming a via connecting the circuit
layers formed on both surfaces of the metal core member.
[0021] The forming the via is performed by forming a through hole
penetrating through the metal core member after the forming the
oxide insulating core layer, forming an insulating layer in an
inner wall of the through hole at the forming the oxide insulating
layer, and forming the plating layer in an inner wall of the
insulating layer at the forming the circuit layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a cross-sectional view schematically showing a
hybrid heat-radiating substrate according to a preferred embodiment
of the present invention;
[0023] FIGS. 2 to 4 are cross-sectional views schematically showing
a modification example of the hybrid heat-radiating substrate shown
in FIG. 1; and
[0024] FIGS. 5 to 17 are cross-sectional views schematically
showing a manufacturing process of the hybrid heat-radiating
substrate shown in FIGS. 1 to 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Various features and advantages of the present invention
will be more obvious from the following description with reference
to the accompanying drawings.
[0026] The terms and words used in the present specification and
claims should not be interpreted as being limited to typical
meanings or dictionary definitions, but should be interpreted as
having meanings and concepts relevant to the technical scope of the
present invention based on the rule according to which an inventor
can appropriately define the concept of the term to describe most
appropriately the best method he or she knows for carrying out the
invention.
[0027] The above and other objects, features and advantages of the
present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings. In the specification, in adding reference
numerals to components throughout the drawings, it is to be noted
that like reference numerals designate like components even though
components are shown in different drawings. Further, when it is
determined that the detailed description of the known art related
to the present invention may obscure the gist of the present
invention, the detailed description thereof will be omitted.
[0028] Hereinafter, preferred embodiments of the present invention
will be described in detail with reference to the accompanying
drawings.
[0029] FIG. 1 is a cross-sectional view schematically showing a
hybrid heat-radiating substrate (hereinafter, referred to as
heat-radiating substrate) according to a preferred embodiment of
the present invention and FIGS. 2 to 4 are cross-sectional views
schematically showing a modification example of the hybrid
heat-radiating substrate shown in FIG. 1. Hereinafter, the hybrid
heat-radiating substrate (hereinafter, referred to as
heat-radiating substrate) according to the present embodiment will
be described with reference to the figures.
[0030] As shown in FIG. 1, a heat-radiating substrate 100 includes
a metal core layer 110 having larger strength and larger resistance
against warpage than a general resin core layer. The metal core
layer serves to discharge heat generated from the heat generating
elements (not shown) mounted on the heat-radiating substrate 100 to
the outside.
[0031] The metal core layer 110 generally has a quadrangular shape
when being viewed from the top but is not limited thereto.
Therefore, the shape thereof may be changed. The metal core layer
110 may be made of aluminum (Al), nickel (Ni), magnesium (Mg),
titanium (Ti), zinc (Zn), tantalum (Ta), or an alloy thereof.
[0032] An oxide insulating core layer 120 is formed in a thickness
direction of a metal core layer 110 to have a shape where it is
integrated with the metal core layer 110. The oxide insulating core
layer 120, which is a metal oxide layer formed by performing volume
anodizing on the metal core layer 110, has insulating property and
lower thermal conductivity than that of a metal
[0033] As shown in FIG. 1, the oxide insulating core layer 120 may
be formed on one surface of the metal core layer 110 or may be
formed on both surfaces thereof. Further, the plurality of oxide
insulating core layers 120 may be formed on one surface of the
metal core layer 110. Since the oxide insulating core layers 120
are formed by performing volume anodizing on the metal core layer
110, it is not protruded to the outside of the metal core layer 110
but is formed to keep the original shape of the metal core layer.
The area of the oxide insulating core layer 120 is determined by an
area where it contacts an electrolyte solution during the anodizing
treatment and the thickness of the oxide insulating core layer 120
is determined by the anodizing treatment time and the applied
voltage.
[0034] The oxide insulating core layers 120 are mounted with
thermally weakened elements, such that it protects the thermally
weakened elements from heat generated from heat generating elements
(not shown). As a result, the metal core layer 110 serves to
discharge heat and the oxide insulating core layer 120 serves to
prevent heat from being transferred, such that a thermally
separated area is formed on a single heat-radiating substrate
100.
[0035] In this configuration, when the metal core layer 110 is made
of aluminum, the oxide insulating core layer 120 is made of alumina
(Al.sub.2O.sub.3). The aluminum is light, excellent in thermal
conductivity, and easy in the anodizing treatment, as compared to
the above-mentioned metals (nickel (Ni), magnesium (Mg), titanium
(Ti), zinc (Zn), tantalum (Ta)).
[0036] In this case, it is preferred that the oxide insulating core
layer 120 is formed so that one side or two adjacent sides of the
oxide insulating core layer 120 are exposed to the outside. When
being viewed from the top, if the edges of the metal core layer 110
are formed with the oxide insulating core layers 120, one side of
the oxide insulating core layer 120 is exposed to the outside and
if a vertex of the metal core layer 110 is formed with the oxide
insulating core layer, two consecutive sides thereof are exposed to
the outside.
[0037] When the heat-radiating substrate 100 shown in FIG. 1 is
considered to be three-dimensional; the oxide insulating core layer
120 has a structure where all four sides thereof are surrounded by
the metal core layer 110. Unlike this, when one side or two
adjacent sides of the oxide insulating core layer are exposed to
the outside, the contact area between the oxide insulating core
layer 120 and the metal core layer 110 is reduced and an amount of
heat transferred to the oxide insulating core layer 120 is reduced
accordingly, which is advantageous in protecting the thermally
weakened elements.
[0038] The oxide insulating layer 130 is formed on one surface or
both surfaces of the metal core layer 110 and serves to separate
the circuit layer 140 and the metal core layer 110 that are formed
on the heat-radiating substrate. Further, as shown in FIG. 1, the
oxide insulating layer 130 may also be formed on the side of the
metal core layer 110.
[0039] The oxide insulating layer 130 forms the outer surface of
the heat-radiating substrate together with the above-mentioned
oxide insulating core layer 120; however, it has a thin film shape
unlike the oxide insulating core layer 120 such that it has a thin
thickness.
[0040] The oxide insulating layer 130 is formed by performing a
surface anodizing treatment on the metal core layer 110 on which
the oxide insulating core layer 120 is formed. Therefore, when the
metal core layer 110 is made of aluminum, the oxide insulating
layer 130 is also made of alumina (Al.sub.2O.sub.3).
[0041] The circuit layer 140 includes first circuit patterns 140-1
formed on the oxide insulating core layers 120 and second circuit
patterns 140-2 formed on the oxide insulating layer 130. The first
circuit patterns 140-1 and the second circuit patterns 140-2 are
connected to each other to be able to transfer electrical signals
to each other. In addition, as shown in FIG. 1, the circuit layer
140 may have a structure where a seed layer 141 and a plating layer
142 are stacked. It is apparent to those skilled in the art that
the structure of the circuit layer may be changed according to a
method of manufacturing the same.
[0042] The thermally weakened elements (not shown) such as a driver
IC are mounted on the first circuit patterns 140-1 formed on the
oxide insulating core layers 120 and the heating generation
elements (not shown) such as an insulated gate bipolar transistor
(IGBT) or a diode are mounted on the second circuit patterns 140-2
formed on the oxide insulating layer 130.
[0043] As shown in FIG. 1, the circuit layer 140 has a single layer
structure, which is shown by way of example only and therefore, may
have a multi-layer structure where the insulating layer and the
circuit layer are repeatedly stacked.
[0044] Another heat-radiating substrate 100-1 may further include a
protective layer 150 that protects the circuit layer 140, as shown
in FIG. 2. It is preferable that the protective layer 150 adopts a
solder resist. The solder resist serves to prevent solder from
being applied on the circuit patterns and protects the circuit
layer 140 from being oxidized when performing soldering using a
heat-resistant coating material.
[0045] In this case, it is preferable that the protective layer 150
is formed with an opening part 155 so that a pad part mounted with
electronic components is exposed to the outside.
[0046] A pad protective layer (not shown) may be further formed on
the pad part. The pad protective layer protects the pad part
exposed to the outside from oxidization and improves the
solderability and conductivity of components. The pad protective
layer includes a metal having low corrosion and high conductivity,
such as tin, silver, gold, etc.
[0047] In another heat-radiating substrate 100-2 as shown in FIG.
3, the oxide insulating layers 130 are formed on both surfaces of
the metal core layer 110 and the second circuit patterns 140-2 are
formed on both surfaces of the heat-radiating substrate 100-2.
[0048] The second circuit patterns 140-2 formed on both surfaces of
the heat-radiating substrate 100-2 perform the same function as the
second circuit patterns described with reference to FIGS. 1 and 2
and may have a multi-layer structure and may further include the
protective layer.
[0049] In this case, in FIG. 3, solder balls, etc., are coupled on
the pad parts of the second circuit patterns 140-2 formed on the
lower surface of the heat-radiating substrate 100-2 such that the
heat-radiating substrate 100-2 may be mounted on another circuit
substrate such as a mother board.
[0050] In this case, a via 145 electrically connects the second
circuit patterns 140-2 formed on the upper surface of the
heat-radiating substrate 100-2 to the circuit patterns 140-2 formed
on the lower surface thereof and an insulating layer 135 serves to
prevent a short between the via 145 and the metal core layer
110.
[0051] As shown in FIG. 4, in another heat-radiating substrate
100-3, the oxide insulating core layers 120 may be formed on both
surfaces of the metal core layer 110. The first circuit patterns
140-1 are each formed on the oxide insulating core layers 120
formed on both surfaces of the metal core layer 110, such that the
thermally weakened elements may be mounted.
[0052] When the oxide insulating core layer 120 is formed on both
surfaces of the heat-radiating substrate 100-3, a plurality of
thermally weakened elements can be selectively mounted, thereby
increasing the design degree of freedom of the heat-radiating
substrate.
[0053] The heat-radiating substrate shown in FIG. 1 and the method
of manufacturing the heat-radiating substrate shown in FIG. 2 will
be described with reference to FIGS. 5 to 13.
[0054] As shown in FIG. 5, the metal core member 110 is first
provided. The metal core member 110 forms the metal core layer of
the heat-radiating substrate and may be made of, for example,
aluminum (Al), nickel (Ni), magnesium (Mg), titanium (Ti), zinc
(Zn), tantalum (Ta), or an alloy thereof.
[0055] Next, the oxide insulating core layer 120 is formed on one
surface of the metal core member 110. As shown in FIG. 6, after a
dry film 10 is attached to an area other than an area where the
oxide insulating core layer 120 will be formed, volume anodizing is
performed to form the oxide insulating core layer 120 in the
thickness direction of the metal core member 110.
[0056] In the case where the metal core member 110 is, for example,
an aluminum member, volume anodizing will be described. First, when
the aluminum member reacts with the electrolyte solution, an
aluminum metal is oxidized at an interface (surface of aluminum
member/electrolyte solution) such that aluminum ions (Al.sup.3+)
are generated. Points, at which current density is concentrated,
are formed on the surface of the aluminum member by voltage applied
to the aluminum member. Heat is locally generated at these points,
the activity of the electrolyte solution (in particular, oxalic
acid) is increased, the aluminum metal very rapidly reacts with the
electrolyte solution, and aluminum ions are more generated.
[0057] In addition, the decomposition reaction of water is
generated due to the applied voltage. At this time, the generated
oxygen ions (O.sup.2-) move to the surface of the aluminum member
by force of an electric field and react with the aluminum ions
generated by the electrolyte solution, thereby forming a porous
alumina layer. As the reaction is continued, the porous alumina
layer is grown in the thickness direction of the aluminum member
and thus, the alumina core layer is formed.
[0058] Since the time of volume anodizing is long and the applied
voltage is large, volume anodizing forms the alumina layer having a
larger thickness than that of surface anodizing.
[0059] In addition, since the alumina core layer is formed in the
thickness direction of the aluminum member, even though the alumina
core layer is formed, the original shape of the aluminum member is
kept. In other words, one area of the aluminum member is
substituted into the alumina core layer.
[0060] Thereafter, as shown in FIGS. 7 and 8, surface anodizing is
performed on the metal core member 110 to form the oxide insulating
layer 130.
[0061] The oxide insulating layer 130 is also formed in an area
where it contacts the electrolyte solution and may be formed on one
surface or both surfaces of the metal core member 110 according to
the adhesion of the dry film. As shown in FIG. 8, the oxide
insulating layer 130 may be formed on a side of the metal core
member 110. However, surface anodizing controls the treatment time
and the applied voltage of the anodizing to have the thin film
shape, unlike volume anodizing.
[0062] Meanwhile, the sequence of volume anodizing and surface
anodizing may be changed. For example, when surface anodizing is
performed over the metal core member 110 and then, the dry film is
attached to the oxide insulating layer 130 other than a part
thereof and volume anodizing is performed, the metal oxide layer is
grown in the area where the dry film is not attached in the
thickness direction, thereby forming the oxide insulating core
layer 120.
[0063] Next, the first circuit patterns 140-1 are formed on the
oxide insulating core layer 120 and the second circuit patterns
140-2 are formed on the oxide insulating layer 130, thereby forming
the circuit layer 140 of the heat-radiating substrate 100.
[0064] The first circuit patterns are electrically connected to the
second circuit patterns 140-2. In this case, the first circuit
patterns and the second circuit patterns may be simultaneously
formed to have the shape where they are connected to each other by
one process or they are formed separately and then, may be
electrically connected to each other by a wire bonding process.
[0065] The circuit layer may be generally formed by a semi-additive
process (SAP), a modified semi-additive process (MSAP), a
subtractive method, and so on.
[0066] A process of forming the circuit layer will be briefly
described with reference to FIGS. 9 to 12. First, the seed layer
141 is formed on one surface of the metal core member 110 on which
the oxide insulating core layer 120 and the oxide insulating layer
130 are formed. The plating layer 142 is formed by stacking the
patterned plating resist film 20 and performing the plating process
thereon and then, the plating resist film is removed. Thereafter,
when the seed layer 141 in an area where the plating layer 142 is
not formed is removed by etching, the first circuit patterns 140-1
are formed on the oxide insulating core layer 120 and the second
circuit patterns 140-2 are formed on the oxide insulating layer
130.
[0067] Each of the first circuit patterns 140-1 and the second
circuit patterns 140-2 includes the pad parts. The first circuit
patterns 140-1 are mounted with thermally weakened elements by the
solder ball scheme or the wire bonding scheme and the second
circuit patterns 140-2 are mounted with the heat generating
elements.
[0068] In this case, as shown in FIG. 13, when the protective layer
150 covering the circuit layer 140 is formed prior to mounting the
thermally weakened elements and the heat generating elements, the
heat-radiating substrate shown in FIG. 2 is manufactured.
[0069] The protective layer 150 may be configured of the solder
resist and may be formed by any one of a screen printing method, a
roller coating method, a curtain coating method, and a spray
coating method. It is preferable that the protective layer 150 is
provided with an opening part 155 to expose the pad parts included
in the circuit layer 140.
[0070] The pad protecting layer (not shown) may further be formed
on the pad part exposed to the outside by outer surface treatment
processes such as an electrolysis plating method, an electroless
plating method, electroless nickel/palladium/gold plating method,
etc.
[0071] Meanwhile, the heat-radiating substrate having a multi-layer
structure may be manufactured by performing a build-up process that
repeatedly stacks the insulating layer and the circuit layer prior
to forming the protective layer 150.
[0072] The method of manufacturing the heat-radiating substrate
shown in FIGS. 3 and 4 will be described with reference to FIGS. 14
to 17. The circuit layers are formed on both surfaces of the
heat-radiating substrate 100-2 shown in FIG. 3. The method of
manufacturing the heat-radiating substrate according to the
exemplary embodiment further includes forming the via that connects
the circuit layers formed on both surfaces of the metal core
member.
[0073] The via may be formed by forming a through hole on the
heat-radiating substrate having the circuit layer formed on both
surfaces thereof and then, filling a conductive material in the
through hole or by forming the through hole and then, performing
the plating process.
[0074] Further, as shown in FIGS. 14 to 16, the via may be
progressively formed simultaneously with the process of forming the
circuit layer.
[0075] As shown in FIG. 14, the metal core member 110 on which the
oxide insulating core layer 120 is formed is first prepared. The
metal core member 110 is formed by the above-mentioned methods with
reference to FIGS. 5 to 7 and therefore, the detailed description
thereof will be described.
[0076] Next, as shown in FIG. 15, a through hole 115 is formed on
the metal core member 110 on which the oxide insulating core layer
120 is formed. A mechanical drill scheme using a drill bit and a
laser processing scheme using YAG laser, CO.sub.2 laser may be
used.
[0077] Thereafter, as shown in FIG. 16, the insulating layer 135 is
formed in an inner wall of the through hole 115. The insulating
layer 135 serves to electrically separate the metal core member 110
and the via 145. The process is performed simultaneously with the
surface anodizing process forming the oxide insulating layer 130 on
the outer surface of the metal core member 110 and thus, the
manufacturing process is reduced and productivity is improved.
[0078] As shown in FIG. 17, the via 145 connecting the circuit
layers 140 formed on both surfaces of the heat-radiating substrate
is formed in the insulating layer 135. Generally, the via is formed
through the plating process and the manufacturing process may be
reduced by simultaneously forming the circuit layer 140 and the
via.
[0079] For example, after the plating layer is formed, the via 145
and the circuit layer 140 may be simultaneously formed by a panel
plating method performing a picture developing process and an
etching process and the pattern plating method may be applied.
[0080] According to the present invention, the hybrid
heat-radiating substrate adopts the metal core layer to easily
discharge heat generated from the heat generating elements, thereby
making it possible to keep the performance of the heat generating
elements in the optimized state.
[0081] Further, according to the present invention, the hybrid
heat-radiating substrate includes the oxide insulating core layer
on which the thermally weakened elements are mounted to thermally
separate the heat generating elements and the thermally weakened
elements so that heat generated from the heat generating elements
is not transferred to the thermally weakened elements mounted on
the same substrate while keeping the heat-radiating property.
[0082] In addition, according to the present invention, the hybrid
heat-radiating substrate has the shape where the metal core layer
is integrated with the oxide insulating core layer such that it is
sturdier than the case where two core layers are physically
separated from each other or bonded to each other by an adhesive,
and so on.
[0083] Moreover, according to the present invention, the method of
manufacturing the hybrid heat-radiating substrate does not depend
on a scheme that forms the heat generating elements and the
thermally weakened elements on a separate substrate and bonds them
to each other but depends on a scheme that directly forms the oxide
insulating core layer on the metal core layer through volume
anodizing, thereby reducing the manufacturing time and improving
productivity.
[0084] Although the embodiments of the present invention has been
disclosed for illustrative purposes, those skilled in the art will
appreciate that various modifications, additions and substitutions
are possible, without departing from the scope and spirit of the
invention. Accordingly, such modifications, additions and
substitutions should also be understood to fall within the scope of
the present invention.
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