U.S. patent application number 13/293130 was filed with the patent office on 2013-02-21 for structure and process of heat dissipation substrate.
This patent application is currently assigned to Subtron Technology Co., Ltd.. The applicant listed for this patent is Tzu-Shih Shen. Invention is credited to Tzu-Shih Shen.
Application Number | 20130043016 13/293130 |
Document ID | / |
Family ID | 47711798 |
Filed Date | 2013-02-21 |
United States Patent
Application |
20130043016 |
Kind Code |
A1 |
Shen; Tzu-Shih |
February 21, 2013 |
STRUCTURE AND PROCESS OF HEAT DISSIPATION SUBSTRATE
Abstract
Structure of a heat dissipation substrate including a metal
substrate, a first insulating material, a second insulating
material, a first patterned conductive layer and a second patterned
conductive layer is provided. The metal substrate has an upper
surface and a lower surface opposite to each other, a plurality of
first recesses located on the upper surface and a plurality of
second recesses located on the lower surface. The first insulating
material is provided to fill into the first recesses. The second
insulating material is provided to fill into the second recesses.
The first patterned conductive layer is disposed on the upper
surface of the metal substrate and a portion of the first
insulating material. The second patterned conductive layer is
disposed on the lower surface of the metal substrate and a portion
of the second insulating material.
Inventors: |
Shen; Tzu-Shih; (Hsinchu,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shen; Tzu-Shih |
Hsinchu |
|
TW |
|
|
Assignee: |
Subtron Technology Co.,
Ltd.
Hsinchu
TW
|
Family ID: |
47711798 |
Appl. No.: |
13/293130 |
Filed: |
November 10, 2011 |
Current U.S.
Class: |
165/185 ;
29/890.03 |
Current CPC
Class: |
H01L 21/4878 20130101;
H01L 23/142 20130101; F28D 2021/0029 20130101; H01L 23/13 20130101;
H01L 2924/181 20130101; F28F 21/085 20130101; H01L 2224/48091
20130101; H01L 33/64 20130101; H01L 2924/181 20130101; F28F 13/00
20130101; Y10T 29/4935 20150115; H01L 2224/48091 20130101; H01L
2924/00014 20130101; H01L 2924/00012 20130101 |
Class at
Publication: |
165/185 ;
29/890.03 |
International
Class: |
F28F 7/00 20060101
F28F007/00; B21D 53/02 20060101 B21D053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 19, 2011 |
TW |
100129781 |
Claims
1. A process of fabricating a heat dissipation substrate, the
process comprising: providing a metal substrate having an upper
surface and a lower surface opposite to each other, a plurality of
first recesses located on the upper surface, and a plurality of
second recesses located on the lower surface, wherein the metal
substrate is divided into a plurality of carrier units and a
plurality of connecting units connecting the carrier units; filling
a first insulating material into the first recesses and a second
insulating material into the second recesses; forming a first
conductive layer on the upper surface of the metal substrate and
the first insulating material and a second conductive layer on the
lower surface of the metal substrate and the second insulating
material; patterning the first conductive layer and the second
conductive layer to form a first patterned conductive layer and a
second patterned conductive layer; and taking the first insulating
material and the second insulating material as an etching mask to
etch the connecting units of the metal substrate so as to form a
plurality of individual heat dissipation substrates.
2. The process of fabricating the heat dissipation substrate as
claimed in claim 1, wherein a method of forming the first recesses
and the second recesses comprises an etching.
3. The process of fabricating the heat dissipation substrate as
claimed in claim 1, wherein a method of forming the first
conductive layer and the second conductive layer comprises an
electroplating.
4. The process of fabricating the heat dissipation substrate as
claimed in claim 1, wherein the metal substrate has a thickness
less than 0.6 millimeter (mm).
5. A structure of the heat dissipation substrate fabricated using
the process for fabricating the heat dissipation substrate as
claimed in claim 1, the structure comprising: a metal substrate
having an upper surface and a lower surface opposite to each other,
a plurality of first recesses located on the upper surface, and a
plurality of second recesses located on the lower surface; a first
insulating material filled into the first recesses; a second
insulating material filled into the second recesses; a first
patterned conductive layer disposed on the upper surface of the
metal substrate and a portion of the first insulating material; and
a second patterned conductive layer disposed on the lower surface
of the metal substrate and a portion of the second insulating
material.
6. The structure of the heat dissipation substrate as claimed in
claim 5, wherein the first insulating material substantially aligns
with the upper surface of the metal substrate.
7. The structure of the heat dissipation substrate as claimed in
claim 5, wherein the second insulating material substantially
aligns with the lower surface of the metal substrate.
8. The structure of the heat dissipation substrate as claimed in
claim 5, wherein the metal substrate has a thickness less than 0.6
mm.
9. The structure of the heat dissipation substrate as claimed in
claim 5, wherein a material of the metal substrate comprises
copper, and the first insulating material and the second insulating
material comprise a glass fiber film.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Taiwan
application serial no. 100129781, filed on Aug. 19, 2011. The
entirety of the above-mentioned patent application is hereby
incorporated by reference herein and made a part of this
specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a metal substrate, more
particularly, the invention relates to a structure of a heat
dissipation substrate adopted in a heating device and a fabricating
process of the same.
[0004] 2. Description of Related Art
[0005] With the progression in fabricating technology, light
emitting diodes (LEDs) have gradually increased the light emitting
efficiency through persistent research and improvement to further
enhance the light emitting brightness thereof so as to satisfy
demands in various products. In other words, other than improving
the external packaging thereof, LEDs also require advanced design
to achieve higher electrical power and working current, which would
lead to the fabrication of LEDs with high brightness. However, when
the electrical power and the working current of LEDs are increased,
LEDs generate higher thermal energy which then affects the
performance of LEDs or results in the malfunction of LEDs by
overheat.
[0006] Conventionally, a copper substrate is adopted in a heat
dissipation substrate for an etching process, so that a plurality
of recesses is formed on an upper surface of the copper substrate.
Thereafter, an insulating material is provided to fill the
recesses, where the insulating material substantially aligns with
the upper surface of the copper substrate. A copper layer is then
electroplated on the upper surface of the copper substrate and the
insulating material. A patterning process is performed to the
copper layer to form a patterned copper layer. Finally, a plurality
of independent heat dissipation substrates is formed through a
singulation process to complete the fabrication of the heat
dissipation substrates.
[0007] In general, when conventional heat dissipation substrate has
a thickness more than 1 millimeter (mm), structures of individual
heat dissipation substrates can be formed rapidly by punching as
the larger heat dissipation substrate has sufficient flexural
strength. Obviously, structures of individual heat dissipation
substrates can also be formed through etching in the fabrication of
conventional heat dissipation substrate. Since the etching process
requires an additional photo-resist layer covering on the copper
substrate and the copper layer of the insulating material,
additional steps and fabrication cost are needed. Moreover, when
the thickness of the heat dissipation substrate is reduced in half
to satisfy the trend of miniaturization in packaging technology so
that the thickness of the heat dissipation substrate is decreased
from 1 mm to less than 0.6 mm, the heat dissipation substrate
easily bends and deforms due to insufficient flexural strength,
thereby affecting the subsequent packaging process.
SUMMARY OF THE INVENTION
[0008] The invention is directed to a structure of a heat
dissipation substrate and a process of fabricating the same, where
the process is capable of reducing fabrication steps and
fabrication cost.
[0009] The invention is directed to a process of fabricating a heat
dissipation substrate, the process includes the following. A metal
substrate is provided. The metal substrate has an upper surface and
a lower surface opposite to each other, a plurality of first
recesses located on the upper surface, and a plurality of second
recesses located on the lower surface. The metal substrate is
divided into a plurality of carrier units and a plurality of
connecting units connecting the carrier units. A first insulating
material is filled into the first recesses and a second insulating
material is filled into the second recesses. A first conductive
layer is formed on the upper surface of the metal substrate and the
first insulating material and a second conductive layer is formed
on the lower surface of the metal substrate and the second
insulating material. The first conductive layer and the second
conductive layer are patterned to form a first patterned conductive
layer and a second patterned conductive layer. The first insulating
material and the second insulating material are taken as an etching
mask to etch the connecting units of the metal substrate so as to
form a plurality of individual heat dissipation substrates.
[0010] According to an embodiment of the invention, a method of
forming the first recesses and the second recesses includes an
etching.
[0011] According to an embodiment of the invention, a method of
forming the first conductive layer and the second conductive layer
includes an electroplating.
[0012] According to an embodiment of the invention, the metal
substrate has a thickness less than 0.6 millimeter (mm).
[0013] The invention is directed to a structure of a heat
dissipation substrate including a metal substrate, a first
insulating material, a second insulating material, a first
patterned conductive layer, and a second patterned conductive
layer. The metal substrate has an upper surface and a lower surface
opposite to each other, a plurality of first recesses located on
the upper surface, and a plurality of second recesses located on
the lower surface. The first insulating material is filled into the
first recesses. The second insulating material is filled into the
second recesses. The first patterned conductive layer is disposed
on the upper surface of the metal substrate and a portion of the
first insulating material. The second patterned conductive layer is
disposed on the lower surface of the metal substrate and a portion
of the second insulating material.
[0014] According to an embodiment of the invention, the first
insulating material substantially aligns with the upper surface of
the metal substrate.
[0015] According to an embodiment of the invention, the second
insulating material substantially aligns with the lower surface of
the metal substrate.
[0016] According to an embodiment of the invention, the metal
substrate has a thickness less than 0.6 mm.
[0017] According to an embodiment of the invention, a material of
the metal substrate includes copper, and the first insulating
material and the second insulating material includes a glass fiber
film.
[0018] In light of the foregoing, in the invention, the first
insulating material and the second insulating material are taken as
the etching mask to etch the connecting units of the metal
substrate so as to form a plurality of individual heat dissipation
substrates. Therefore, comparing to conventional fabrication which
requires an additional photo-resist layer as the etching mask, the
process of fabricating the heat dissipation substrate in the
invention can reduce the fabrication steps and fabrication
cost.
[0019] In order to make the aforementioned and other features and
advantages of the invention more comprehensible, several
embodiments accompanied with figures are described in detail
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings are included to provide further
understanding, and are incorporated in and constitute a part of
this specification. The drawings illustrate embodiments and,
together with the description, serve to explain the principles of
the invention.
[0021] FIGS. 1A to 1E are schematic cross-sectional views
illustrating a flowchart of a fabrication process of a heat
dissipation substrate in one embodiment of the invention.
[0022] FIG. 1F is a schematic cross-sectional view of a heating
device loaded on a heat dissipation substrate in FIG. 1E.
DESCRIPTION OF EMBODIMENTS
[0023] FIGS. 1A to 1E are schematic cross-sectional views
illustrating a flowchart of a fabrication process of a heat
dissipation substrate in one embodiment of the invention. FIG. 1F
is a schematic cross-sectional view of a heating device loaded on a
heat dissipation substrate in FIG. 1E. Referring to FIG. 1A,
according to a method of fabricating a heat dissipation substrate
of the present embodiment, a metal substrate 110 is first provided.
The metal substrate 110 has an upper surface 112 and a lower
surface 114 opposite to each other. The metal substrate 110 has a
thickness T1 less than 0.6 millimeter (mm) and is fabricated with
copper, for example.
[0024] Referring to FIG. 1A, a plurality of first recesses 116 is
formed on the upper surface 112 of the metal substrate 110 and a
plurality of second recesses 118 is formed on the lower surface 114
of the metal substrate 110. Here, positions of the first recesses
116 correspond to positions of the second recesses 118
respectively. In the present embodiment, the metal substrate 110 is
divided into a plurality of carrier units 110a (only two carrier
units 110a are illustrated in FIG. 1A) and a plurality of
connecting units 110b connecting to the carrier units 110a (only
one connecting unit 110b is shown in FIG. 1A). Each of the
connecting units 110b is disposed between two closer first recesses
116 and between two closer second recesses 118. Here, a depth T2 of
each of the first recesses 116 is preferably 0.05 mm and a depth T3
of each of the second recesses 118 is preferably 0.05 mm. In
addition, a method of forming the first recesses 116 and the second
recesses 118 is an etching, for instance.
[0025] Referring to FIG. 1B, a first insulating material 120 is
filled into the first recesses 116 and a second insulating material
130 is filled into the second recesses 118. Here, the first
insulating material 120 and the second insulating material 130 are,
for example, glass fiber films. The first insulating material 120
substantially aligns with the upper surface 112 of the metal
substrate 110. The second insulating material 130 substantially
aligns with the lower surface 114 of the metal substrate 110.
[0026] Thereafter, referring to FIG. 1C, a first conductive layer
140 is formed on the upper surface 112 of the metal substrate 110
and the first insulating material 120, and a second conductive
layer 150 is formed on the lower surface 114 of the metal substrate
110 and the second insulating material 130. The first conductive
layer 140 covers the upper surface 112 of the metal substrate 110
and the first insulating material 120 entirely. The second
conductive layer 150 covers the lower surface 114 of the metal
substrate 110 and the second insulating material 130 entirely.
Herein, a method of forming the first conductive layer 140 and the
second conductive layer 150 is, for instance, an
electroplating.
[0027] Referring to FIG. 1D, the first conductive layer 140 and the
second conductive layer 150 are patterned to form a first patterned
conductive layer 142 and a second patterned conductive layer 152.
The first patterned conductive layer 142 exposes a portion of the
first insulating material 120 and the second patterned conductive
layer 152 exposes a portion of the second insulating material 130.
At this time, the first patterned conductive layer 142 and the
second patterned conductive layer 152 also expose the connecting
units 110b.
[0028] Finally, referring to FIG. 1E, the first insulating material
120 and the second insulating material 130 are taken as an etching
mask to perform a single etching step for etching the connecting
units 110a of the metal substrate 110, thereby forming structures
of a plurality of individual heat dissipation substrates 100 (only
one is displayed in FIG. 1D).
[0029] In terms of the structure, referring to FIG. 1E, the heat
dissipation substrate 100 of the present embodiment includes a
metal substrate 110, a first insulating material 120, a second
insulating material 130, a first patterned conductive layer 142,
and a second patterned conductive layer 152. The metal substrate
110 has the upper surface 112 and the lower surface 114 opposite to
each other, the first recesses 116 disposed on the upper surface
112, and the second recesses 118 disposed on the lower surface 114.
The thickness T1 of the metal substrate 110 is less than 0.6 mm.
The first insulating material 120 is filled into the first recesses
116, where the first insulating material 120 substantially aligns
with the upper surface 112 of the metal substrate 110. The second
insulating material 130 is filled into the second recesses 118,
where the second insulating material 130 substantially aligns with
the lower surface 114 of the metal substrate 110. The first
patterned conductive layer 142 is disposed on the upper surface 112
of the metal substrate 110 and a portion of the first insulating
material 120. The second patterned conductive layer 152 is disposed
on the lower surface 114 of the metal substrate 110 and a portion
of the second insulating material 130.
[0030] In the present embodiment, the first insulating material 120
and the second insulating material 130 are taken as the etching
mask to etch the connecting units 110b of the metal substrate 110
so as to form a plurality of individual heat dissipation substrates
100. Thus, comparing to conventional fabrication which requires an
additional photo-resist layer as the etching mask, the process of
fabricating the heat dissipation substrates 100 in the present
embodiment can reduce the fabrication steps and fabrication
cost.
[0031] Moreover, although the thickness of the metal substrate 110
is less than 0.6 mm in the present embodiment, that is, the
thickness of the metal substrate 110 in the present embodiment is
less than half of the thickness of a conventional copper substrate,
the stress on the upper surface 112 and the lower surface 114 of
the metal substrate is offset by the symmetrical recessive
structures (that is, the first recesses 116 and the second recesses
118), the insulating materials (that is, the first insulating
material 120 and the second insulating material 130), and the
circuit layers (that is, the first patterned conductive layer 142
and the second patterned conductive layer 152). In other words, the
heat dissipation substrate 100 of the present embodiment is a
double-sided plate. Accordingly, the heat dissipation substrate 100
of the present embodiment has sufficient flexural strength.
[0032] Furthermore, in the subsequent fabricating process,
referring to FIG. 1F, when a heating device 10 is electrically
connected to the first patterned conductive layer 142 of the heat
dissipation substrate 100 through a wire bonding process and the
heating device 10 is covered using an encapsulant 30, an individual
light emitting device package structure is then formed. Here, the
first patterned conductive layer 142 exposed outside of the
encapsulant 30 is protected by a solder-resist layer 160. The heat
dissipation substrate 100 is electrically connected to an external
circuit (not shown) through the second patterned conductive layer
152 so as to expand the application scope of the heat dissipation
substrate 100.
[0033] In summary, the first insulating material and the second
insulating material are taken as the etching mask in the invention
to etch the connecting units of the metal substrate for forming a
plurality of individual heat dissipation substrates. Therefore,
comparing to conventional fabrication which requires an additional
photo-resist layer as the etching mask, the process of fabricating
the heat dissipation substrate in the invention can reduce the
fabrication steps and fabrication cost. Also, since the thickness
of the metal substrate in the invention is less than 0.6 mm and the
upper surface and the lower surface of the metal substrate are
disposed with the recessive structures, the insulating materials,
and the patterned conductive layers simultaneously, the stress on
the upper surface and the lower surface of the metal substrate can
be offset for the heat dissipation substrate of the invention to
have sufficient flexural strength. In addition, when the heating
device is electrically connected to the patterned conductive layer
through a wire bonding process to form a packaging structure, this
packaging structure has a thinner packaging thickness.
[0034] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
disclosed embodiments without departing from the scope or spirit of
the invention. In view of the foregoing, it is intended that the
invention cover modifications and variations of this invention
provided they fall within the scope of the following claims and
their equivalents.
* * * * *