U.S. patent application number 11/383168 was filed with the patent office on 2007-11-15 for heat dissipating type printed circuit board and structure thereof for conducting heat with heap pipe.
Invention is credited to Ting-Kuo Kao, Tse-Hsine Laio.
Application Number | 20070263362 11/383168 |
Document ID | / |
Family ID | 38664630 |
Filed Date | 2007-11-15 |
United States Patent
Application |
20070263362 |
Kind Code |
A1 |
Laio; Tse-Hsine ; et
al. |
November 15, 2007 |
HEAT DISSIPATING TYPE PRINTED CIRCUIT BOARD AND STRUCTURE THEREOF
FOR CONDUCTING HEAT WITH HEAP PIPE
Abstract
A heat dissipating type printed circuit board and its structure
for conducting heat with a heat pipe include a substrate, a signal
circuit disposed on a surface of the substrate and electrically
coupled to an electronic component, a heat dissipating layer
disposed on another surface of the substrate, and at least one heat
pipe, each having a heated end and a condensing end extended from
the heated end. The substrate includes a through hole passing
through the heat dissipating layer, and the heat dissipating layer
includes an adhering layer disposed at a surface proximate to the
surroundings of the heat pipe, and a distal end of the heated end
of the heat pipe is covered by the adhering layer, and the adhering
layer is extended from the surface of the heat dissipating layer to
a corresponding position of the electronic component.
Inventors: |
Laio; Tse-Hsine; (Xindian
City, TW) ; Kao; Ting-Kuo; (Xindian City,
TW) |
Correspondence
Address: |
HDSL
4331 STEVENS BATTLE LANE
FAIRFAX
VA
22033
US
|
Family ID: |
38664630 |
Appl. No.: |
11/383168 |
Filed: |
May 12, 2006 |
Current U.S.
Class: |
361/719 ;
257/E23.088; 257/E23.105 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 2924/0002 20130101; H01L 23/3677 20130101; H01L 23/427
20130101; H05K 2201/09781 20130101; H05K 3/3447 20130101; H05K
2201/10166 20130101; H05K 2203/044 20130101; H05K 1/0206 20130101;
H05K 1/0209 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
361/719 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1 A heat dissipating type printed circuit board, comprising: a
substrate, having a signal circuit disposed on a surface of the
substrate and electrically coupled to an electronic device; a heat
dissipating layer, disposed on another surface of the substrate;
and at least one heat pipe, having a heated end and a condensing
end extended from the heated end, wherein the substrate includes a
through hole penetrating the heat dissipating layer, and an
adhering layer disposed on a surface of the heat dissipating layer
and proximate to the surroundings of the heat pipe, and a distal
end of the heated end of the heat pipe is covered by the adhering
layer, and the adhering layer is extended from a surface of the
heat dissipating layer to a corresponding position of the
electronic device.
2. The heat dissipating type printed circuit board of claim 1,
wherein the substrate includes a plurality of penetrating holes,
each disposed at a corresponding position of the electronic device,
and the penetrating holes are filled up by the adhering layer for
having a thermal conducting contact with the heat dissipating
layer.
3. The heat dissipating type printed circuit board of claim 1,
wherein a wall of the through hole of the substrate includes a
thermal conducting medium disposed between the heat pipe and the
substrate.
4. The heat dissipating type printed circuit board of claim 3,
wherein the thermal conducting medium is a heat dissipating
paste.
5. The heat dissipating type printed circuit board of claim 3,
wherein the thermal conducting medium and the heat dissipating
layer are made of the same material.
6. The heat dissipating type printed circuit board of claim 3,
wherein the thermal conducting medium and the adhering layer are
made of the same material.
7. The heat dissipating type printed circuit board of claims 1,
wherein the heat dissipating layer is a copper foil.
8. The heat dissipating type printed circuit board of claims 1,
wherein the adhering layer is made of a solder.
9. The heat dissipating type printed circuit board of claim 1,
wherein a remaining surface of the heat dissipating layer is
covered by an insulating coating.
10. The heat dissipating type printed circuit board of claim 1,
wherein the condensing end of the heat pipe includes a plurality of
heat dissipating fins.
11. A structure of a printed circuit board for conducting heat with
a heat pipe, comprising: a printed circuit board, having a
substrate, a signal circuit disposed on a surface of the substrate,
a heat dissipating layer disposed on another surface of the
substrate, and a through hole disposed on the substrate and passing
through the heat dissipating layer; and at least one heat pipe,
having a heated end passing through the through hole of the
substrate, so that a distal end of the heated end is protruded out
from the heat dissipating layer, wherein, the heat dissipating
layer includes an adhering layer disposed on a surface proximate to
the surroundings of the heat pipe, and the distal end of the heated
end of the heat pipe is covered by the adhering layer.
12. The structure of a printed circuit board for conducting heat
with a heat pipe of claim 11, wherein a wall of the through hole of
the substrate includes a thermal conducting medium disposed between
the heat pipe and the substrate.
13. The structure of a printed circuit board for conducting heat
with a heat pipe of claim 12, wherein the thermal conducting medium
is a heat dissipating paste.
14. The structure of a printed circuit board for conducting heat
with a heat pipe of claim 12, wherein the thermal conducting medium
and the heat dissipating layer are made of the same material.
15. The structure of a printed circuit board for conducting heat
with a heat pipe of claim 12, wherein the thermal conducting medium
and the adhering layer are made of the same material.
16. The structure of a printed circuit board for conducting heat
with a heat pipe of claims 11, wherein the heat dissipating layer
is a copper foil.
17. The structure of a printed circuit board for conducting heat
with a heat pipe of claims 11, wherein the adhering layer is made
of a solder.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat dissipating type
printed circuit board and its structure for conducting heat with a
heat pipe, and more particularly to a thermal conducting structure
connected to a printed circuit board for providing high-performance
heat dissipations for the printed circuit board and conducting heat
with a heat pipe.
[0003] 2. Description of Prior Art
[0004] To enhance the heat dissipating effect of a printed circuit
board (PCB), most printed circuit boards add heat dissipating
holes, electroplate metal films, install metal lumps on the
backside of the printed circuit boards, or directly coat a heat
dissipating paste onto the printed circuit boards for dissipating
heat.
[0005] Regardless of which one of the foregoing methods is used to
provide the required heat dissipation function for the printed
circuit boards, the best this method can do is to conduct the heat
energy produced by an electronic component to a heat dissipating
hole, a metal film, a metal lump or a heat dissipating paste, but
it cannot provide an effective heat path to conduct the heat to a
farther end. Such arrangement only increases the temperature of
surrounding air, so that when the heat keeps increasing, the
temperature of the air around the printed circuit board will be
affected. Once the temperature of air and the heat dissipating
structure of the printed circuit board reach a thermal equilibrium,
the thermal conducting performance and the heat dissipating effect
of the printed circuit board drop gradually and affect the
electronic components indirectly.
SUMMARY OF THE INVENTION
[0006] In view of the foregoing shortcomings of the prior art, the
inventor of the present invention based on years of experience in
the related industry to conduct experiments and modifications, and
finally designed a feasible solution to overcome the shortcomings
of the prior art.
[0007] The present invention is to overcome the shortcomings of the
prior art by providing a heat dissipating type printed circuit
board and its structure for conducting heat with a heat pipe, so as
to effectively solve the heat dissipating problem of the printed
circuit boards. The invention connects a heat pipe to the printed
circuit board for conducting heat and effectively lowers the
temperature of the printed circuit board and its electronic
components and also allows the electronic components to operate
under a permissible operating temperature and maintain a stable
operation of an electronic system.
[0008] The present invention provides a heat dissipating type
printed circuit board, comprising a substrate, a heat dissipating
layer and at least one heat pipe. The substrate has a signal
circuit disposed on a surface of the substrate and electrically
coupled to an electronic component. The heat dissipating layer is
disposed on another surface of the substrate. The heat pipe has a
heated end, and a condensing end extended from the heated end. The
substrate includes a through hole passing through the heat
dissipating layer and an adhering layer disposed on the heat
dissipating layer proximate to the surroundings of the heat pipe
and a distal end of the heated end of the heat pipe is covered by
the adhering layer, and the adhering layer is extended from the
heat dissipating layer to a corresponding position of the
electronic component.
[0009] The present invention provides a structure of a printed
circuit board for conducting heat with a heat pipe, comprising a
printed circuit board and at least one heat pipe. The printed
circuit board has a substrate, a signal circuit disposed on a
surface of the substrate, a heat dissipating layer disposed on
another surface of the substrate, and a through hole disposed on
the substrate and passing through the heat dissipating layer. The
heat pipe has a heated end passing through the through hole of the
substrate, and a distal end of the heated end being protruded out
from the heat dissipating layer. The heat dissipating layer
includes an adhering layer disposed on a surface proximate to the
surroundings of the heat pipe, and the distal end of the heated end
of the heat pipe is covered by the adhering layer.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The features of the invention believed to be novel are set
forth with particularity in the appended claims. The invention
itself however may be best understood by reference to the following
detailed description of the invention, which describes certain
exemplary embodiments of the invention, taken in conjunction with
the accompanying drawings in which:
[0011] FIG. 1 is a schematic planar view of a first preferred
embodiment of the present invention;
[0012] FIG. 2 is a cross-sectional view of line 2-2 as depicted in
FIG. 1;
[0013] FIG. 3 is another cross-sectional view of line 2-2 as
depicted in FIG. 1;
[0014] FIG. 4 is a further cross-sectional view of line 2-2 as
depicted in FIG. 1;
[0015] FIG. 5 is a schematic planar view of a second preferred
embodiment of the present invention;
[0016] FIG. 6 is a schematic view of a first preferred embodiment
applied in a computer casing according to the present invention;
and
[0017] FIG. 7 is a schematic view of a second preferred embodiment
applied in a computer casing according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The technical characteristics, features and advantages of
the present invention will become apparent in the following
detailed description of the preferred embodiments with reference to
the accompanying drawings. However, the drawings are provided for
reference and illustration only and are not intended for limiting
the scope of the invention.
[0019] Referring to FIG. 1 for the schematic view of a first
preferred embodiment of the present invention, the invention
provides a heat dissipating type printed circuit board and its
structure for conducting heat with a heat pipe, and the printed
circuit board 1 comprises a substrate 10 made of an insulating
material, a signal circuit 101 disposed on a surface of the
substrate 10 and electrically coupled to an electronic component 14
and a heat dissipating layer 11 disposed on another surface of the
substrate 10. The heat dissipating layer 11 can be made of a copper
foil or other heat dissipating metal and an insulating coating 12
is covered onto the heat dissipating layer 11.
[0020] The invention connects the printed circuit board 1 and a
heat pipe 2 for conducting heat, and the heat accumulated at the
heat dissipating layer 11 can be dissipated by the high thermal
conductivity of the heat pipe 2. The heat pipe 2 is a heat
conducting component with a high thermal conducting power, a fast
heat transfer and a high thermal conductivity, and also can
transfer a great deal of heat energy without consuming much
electric power, thus heat pipes have become an extensively used
component for dissipating heat for present electronic products. The
general principle of a heat pipe 2 mainly installs a wick structure
on the internal wall of the heat pipe, and the pipe is in a vacuum
state. The wick structure could be a woven net or a sintered powder
capable of performing a capillary action. With the capillary action
of the wick structure, a working fluid in the heat pipe can be
transmitted easily. If an end of the heat pipe is heated, the
working fluid in the heat pipe will be heated as well, and the
working fluid will change its liquid phase into a gas phase. The
heat energy absorbed by the working fluid is conducted to another
end of the heated end and another end is cooled to convert the gas
phase back to the liquid phase. In the meantime, the capillary
action produced by the wick structure drives the working fluid in a
liquid phase back to the heated end of the heat pipe for performing
heat exchanges repeatedly.
[0021] Referring to FIG. 2 as well, the printed circuit board 1 has
a through hole 100 disposed on the substrate 10 and penetrating
through the heat dissipating layer 11 for passing the heat pipe 2,
and the number of through holes 100 depends on the number of heat
pipes 2 being installed. Basically, one through hole 100 is
provided for one heat pipe 2, and there is at least one heat pipe
2. The number of through holes 100 can be increased according to
the actual need of the thermal conduction. The heat pipe 2 has a
heated end 20 and a condensing end 21 extended outwardly from the
heated end 20, wherein the heated end 20 passes through the through
hole 100 of the substrate 10, and a distal end of the heated end 20
is protruded out from the heat dissipating layer 11, and the
surroundings of the through hole 100 of the heat dissipating layer
11 are exposed to the outside. In other words, no insulating
coating 12 is covered on the surroundings of the through hole 100
of the heat dissipating layer 11, and if the heat dissipating layer
11 is made of copper, then such exposed area is known as a bare
copper. If the printed circuit board 1 goes through a soldering
furnace, a solid adhering layer that covers the distal end of the
heated end 20 will be attached onto the heat dissipating layer 11
and disposed proximate to the surroundings of the heat pipe 2, so
as to form a good thermal conducting contact between the heat pipe
2 and the heat dissipating layer 11 of the printed circuit board 1.
The adhering layer 13 could be made of a solder and an appropriate
quantity of solder is protruded to a specific height that gives a
larger surface for improving the heat dissipating performance of
the heat dissipating layer 11. In the meantime, the adhering layer
13 can be extended from the surface of the heat dissipating layer
11 to a corresponding position of the electronic component 14, and
the remaining surface of the heat dissipating layer 11 which is not
attached by the adhering layer is covered by the insulating coating
12 to prevent an excessively large area of the attached adhering
layer 13 that results in an unnecessary cost.
[0022] To increase the contact area between the heat pipe 2 and the
substrate 10, the wall of the through hole 100 includes a layer of
thermal conducting medium disposed between the heat pipe 2 and the
substrate 10 as shown in FIG. 2. The thermal conducting medium and
the heat dissipating layer 11 could be made of the same material
such as a copper foil 110. In FIG. 2, the heat dissipating layer 11
and the thermal conducting medium are plated onto the substrate 10.
In FIG. 3, the thermal conducting medium and the adhering layer 13
could be made of the same material such as a solder 130, so that
when the printed circuit board 1 goes through a soldering furnace,
the liquid solder 130 is permeated through the gap between the heat
pipe 2 and the through hole. In FIG. 4, the thermal conducting
medium could be a heat dissipating paste 131 coated onto the
external wall of the heated end 20 of the heat pipe 2 and passed
through the through hole 100. In the preferred embodiment as shown
in FIG. 2, although the wall of the through hole 100 is plated with
a thermal conducting medium such as a copper foil 110, a heat
dissipating paste 131 still can be coated on the external wall of
the heat end 20 of the heat pipe 2 as shown in FIG. 4, and the
heated end 20 is passed through the through hole 100 having a
copper foil 110 on its wall to improve the contact between the
heated end and the through hole 100.
[0023] In FIG. 1, both printed circuit board 1 and electronic
component 14 produce heat energy when the electronic component 14
starts operating, and the heat energy is absorbed by the heat
dissipating layer 11 and adhering layer 13 first and then conducted
to the heated end 20 of the heat pipe 2. Although some heat
energies will be dissipated from the protrusion of the adhering
layer 13 to the surrounding air in the heat conducting path, a vast
majority of the heat energies are conducted quickly from the heated
end 20 of the heat pipe 2 to the condensing end 21 of the heat pipe
2. The condensing end 21 of the heat pipe 2 has a plurality of heat
dissipating fins 3 for performing heat dissipations for the heat
pipe 2.
[0024] Referring to FIG. 5, the substrate 10 of the printed circuit
board 1 includes a plurality of penetrating holes 102 disposed at
corresponding positions of the electronic components 14 without
causing an electromagnetic interference issue. The penetrating
holes 102 are filled up by the solder 130 of the adhering layer 13
and in contact with the heat dissipating layer 11 for conducting
heat, so that the heat energy produced by the electronic components
14 can be conducted quickly to the heat dissipating layer 11 or the
adhering layer 13, so as to improve the heat dissipating
performance of the printed circuit board 1.
[0025] With the foregoing structure, the heat dissipating type
printed circuit board and its structure for conducting heat with a
heat pipe can be accomplished.
[0026] Therefore, the heat dissipating type printed circuit board
and its structure for conducting heat with a heat pipe in
accordance with the invention can improve the heat dissipation for
a printed circuit board 1, and they can be designed together with a
casing of an electronic product, so that the heat produced by the
printed circuit board 1 and its electronic components 14 can be
conducted to the outside. In FIG. 6, the casing 4 includes a
ventilation outlet 40, and the ventilation outlet 40 has a fan 5,
and the heat dissipating fin 3 corresponds to the fan 5 for
compulsorily discharging the heat energy out of the casing 4. In
FIG. 7, the heat dissipating fin 3 can be extended out of the
ventilation outlet 40 of the casing 4 for facilitating heat
dissipations by the cooler air outside. Both of the foregoing
embodiments can effectively lower the temperature of the printed
circuit board 1 and prevent heat energy from being accumulated in
the casing 4 that will results in a greenhouse effect.
[0027] In summation of the above description, the invention herein
enhances the performance than the conventional structure and
further complies with the patent application requirements.
[0028] The present invention are illustrated with reference to the
preferred embodiment and not intended to limit the patent scope of
the present invention. Various substitutions and modifications have
suggested in the foregoing description, and other will occur to
those of ordinary skill in the art. Therefore, all such
substitutions and modifications are intended to be embraced within
the scope of the invention as defined in the appended claims.
* * * * *