U.S. patent application number 10/435565 was filed with the patent office on 2004-05-06 for heat sink for electronic devices, and circuit board and plasma display panel assembly each equipped with the heat sink.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Choi, Soo Yong, Joo, Jae Man, Kang, Jung Hun, Lee, Seok Yeong, Oh, Sang Kyoung.
Application Number | 20040085737 10/435565 |
Document ID | / |
Family ID | 32171593 |
Filed Date | 2004-05-06 |
United States Patent
Application |
20040085737 |
Kind Code |
A1 |
Choi, Soo Yong ; et
al. |
May 6, 2004 |
HEAT SINK FOR ELECTRONIC DEVICES, AND CIRCUIT BOARD AND PLASMA
DISPLAY PANEL ASSEMBLY EACH EQUIPPED WITH THE HEAT SINK
Abstract
A heat sink for electronic devices, and circuit board and plasma
display panel assembly, each equipped with the heat sink. The heat
sink for electronic devices, and circuit board and PDP assembly
each equipped with the heat sink includes a base portion fixedly
attached to a circuit board, a contact portion fixedly and tightly
brought into contact with one or more electronic devices, and a
plurality of heat radiation fins each extended from the contact
portion to a certain distance. A heat radiation fin distant from
the base portion has a width shorter than that of a heat radiation
fin nearer to the base portion.
Inventors: |
Choi, Soo Yong; (Seoul,
KR) ; Joo, Jae Man; (Kyungki-Do, KR) ; Lee,
Seok Yeong; (Kyungki-Do, KR) ; Kang, Jung Hun;
(Seoul, KR) ; Oh, Sang Kyoung; (Kyungki-Do,
KR) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
|
Family ID: |
32171593 |
Appl. No.: |
10/435565 |
Filed: |
May 12, 2003 |
Current U.S.
Class: |
361/719 ;
257/E23.084 |
Current CPC
Class: |
H01L 23/4006 20130101;
H01L 2924/0002 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
361/719 |
International
Class: |
H05K 007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 1, 2002 |
KR |
2002-67517 |
Claims
What is claimed is:
1. A heat sink for electronic devices, comprising: a base portion
attached to a circuit board; a contact portion where one or more
electronic devices are attached; and a plurality of heat radiation
fins each extended from the contact portion to a certain distance,
wherein at least one of the heat radiation fins distant from the
base portion has a width shorter than that of a heat radiation fin
nearer to the base portion.
2. The heat sink for electronic devices as set forth in claim 1,
wherein one of the plurality of heat radiation fins is attached to
the circuit board and constitutes the base portion.
3. The heat sink for electronic devices as set forth in claim 1,
wherein the contact portion is extended from the base portion to
form a certain angle with the base portion, and the plurality of
heat radiation fins are extended from the contact portion to be
parallel to the base portion.
4. The heat sink for electronic devices as set forth in claim 1,
wherein a heat radiation fin spaced from the base portion by more
than a predetermined distance has a width shorter than that of a
heat radiation fin situated within the predetermined distance.
5. The heat sink for electronic devices as set forth in claim 1,
wherein each one of the heat radiation fins has a width inversely
proportional to a distance thereof from the base portion.
6. The heat sink for electronic devices as set forth in claim 1,
wherein the electronic devices are Metal-Oxide Semiconductor Field
Effect Transistors (MOSFETs).
7. A circuit board equipped with a heat sink, the heat sink being
brought into contact with one or more electronic devices generating
heat and noise to dissipate the heat, the heat sink comprising: a
base portion fixedly attached to a circuit board; a contact portion
fixedly brought into contact with one or more electronic devices;
and a plurality of heat radiation fins each extended from the
contact portion to a certain distance, wherein a heat radiation fin
distant from the base portion has a width shorter than that of a
heat radiation fin nearer to the base portion.
8. The heat sink for electronic devices as set forth in claim 7,
wherein one of the plurality of heat radiation fins is fixedly
attached to the circuit board and constitutes the base portion.
9. The heat sink for electronic devices as set forth in claim 7,
wherein the contact portion is extended from the base portion to
form a certain angle with the base portion, and the plurality of
heat radiation fins are extended from the contact portion to be
parallel to the base portion.
10. The heat sink for electronic devices as set forth in claim 7,
wherein a heat radiation fin spaced from the base portion by more
than a predetermined distance has a width shorter than that of a
heat radiation fin situated within the predetermined distance.
11. The heat sink for electronic devices as set forth in claim 7,
wherein each one of the heat radiation fins has a width inversely
proportional to a distance thereof from the base portion.
12. The heat sink for electronic devices as set forth in claim 7,
wherein the electronic devices are MOSFETs.
13. A plasma display panel assembly equipped with a heat sink, the
heat sink being brought into contact with one or more electronic
devices generating heat and noise to dissipate the heat, the heat
sink and the electronic devices being mounted on one or more
circuit boards, the heat sink comprising: a base portion fixedly
attached to a circuit board; a contact portion fixedly brought into
contact with one or more electronic devices; and a plurality of
heat radiation fins each extended from the contact portion to a
certain distance, wherein a heat radiation fin distant from the
base portion has a width shorter than that of a heat radiation fin
nearer to the base portion.
14. The heat sink for electronic devices as set forth in claim 13,
wherein one of the plurality of heat radiation fins is fixedly
attached to the circuit board and constitutes the base portion.
15. The heat sink for electronic devices as set forth in claim 13,
wherein the contact portion is extended from the base portion to
form an angle with the base portion, and the plurality of heat
radiation fins are extended from the contact portion to be parallel
to the base portion.
16. The heat sink for electronic devices as set forth in claim 13,
wherein a heat radiation fin spaced from the base portion by more
than a predetermined distance has a width shorter than that of a
heat radiation fin situated within the predetermined distance.
17. The heat sink for electronic devices as set forth in claim 13,
wherein each one of the heat radiation fins has a width inversely
proportional to a distance thereof from the base portion.
18. The heat sink for electronic devices as set forth in claim 13,
wherein the electronic devices are MOSFETs.
19. The heat sink for electronic devices as set forth in claim 15,
wherein the contact portion is extended from the base portion to
form a ninety-degree angle with the base portion.
20. The heat sink for electronic devices as set forth in claim 13,
wherein the widths of the plurality of heat radiation fins are
determined so that each of the vibration amplitudes of the heat
radiation fins are less than a certain level.
21. The heat sink for electronic devices as set forth in claim 13,
wherein at least two heat radiation fins have the same width.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Application
No. 2002-67517, filed Nov. 01, 2002, in the Korean Intellectual
Property Office, the disclosures of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a heat sink for
electronic devices, and circuit board and plasma display panel
assembly, each equipped with the heat sink, and more particularly
to a heat sink for electronic devices, and circuit board and plasma
display panel assembly each equipped with the heat sink that is
capable of reducing noise.
[0004] 2. Description of the Related Art
[0005] In general, a circuit board, which is installed in various
electronic apparatuses, is equipped with a plurality of electronic
devices and performs programmed operations through the interaction
with these electronic devices.
[0006] These electronic devices are supplied with electric power
and perform predetermined operations. Some of these electronic
devices generate heat and vibration according to their operational
characteristics during operation.
[0007] The electronic devices that generate heat and vibration are
exemplified by a Metal-Oxide Semiconductor Field Effect Transistor
(MOSFET).
[0008] The MOSFET is applied to a Plasma Display Panel (PDP) to
discharge electricity in each of the cells of the PDP. The MOSFET
generates heat while switching on/off voltage supplied to each of
the cells of the PDP.
[0009] FIG. 1 is a view showing a MOSFET 2 and a conventional heat
sink 3 for electronic devices that are fixedly attached to a
circuit board 1.
[0010] As illustrated in FIG. 1, the conventional heat sink 3 for
electronic devices includes a base portion 3a fastened to the
circuit board 1, a contact portion 3b extended from the base
portion 3a and brought into contact at one side thereof with the
MOSFET 2, and a plurality of heat radiation fins 3c that are
extended from the contact portion 3b to be regularly spaced apart
from each other.
[0011] Accordingly, heat is transmitted to the heat radiation fins
3c through the contact portion 3b of the heat sink 3, and radiated
to the air through the heat radiation fins 3c.
[0012] Electromagnetic force is generated in the MOSFET 2 when the
MOSFET 2 switches on the voltage, while electromagnetic force is
eliminated when the MOSFET 2 switches off the voltage. Accordingly,
when the MOSFET 2 is turned on/off to perform this switching
operation, electromagnetic force is repeatedly generated and
extinguished, thereby vibrating the MOSFET 2.
[0013] When the MOSFET 2 vibrates, a vibration is transmitted to
the heat sink 3 that is used to cool the MOSFET 2. The transmitted
vibration vibrates the plurality of heat radiation fins 3c of the
heat sink 3, and consequently generates noise. Since the heat
radiation fins 3c vibrate in proportion to the distance from the
base portion 3a fastened to the circuit board 1, the heat radiation
fins 3c generate noise in proportion to their distance from the
base portion 3a.
[0014] In particular, where the conventional heat sink for
electronic devices is applied to a television set of a home theater
system and generates excessive noise, users may complain about the
excessive noise of products.
SUMMARY OF THE INVENTION
[0015] Accordingly, it is an aspect of the present invention to
provide a heat sink for electronic devices, and circuit board and
plasma display panel assembly, each equipped with the heat sink,
which is capable of reducing noise.
[0016] Additional aspects and advantages of the invention will be
set forth in part in the description that follows and, in part,
will be obvious from the description, or may be learned by practice
of the invention.
[0017] The foregoing and other aspects of the present invention are
achieved by providing a heat sink for electronic devices, and
circuit board and PDP assembly, each equipped with the heat sink,
including a base portion fixedly attached to a circuit board, a
contact portion fixedly and tightly brought into contact with one
or more electronic devices, and a plurality of heat radiation fins
each extended from the contact portion to a certain distance; and
wherein a heat radiation fin distant from the base portion has a
width shorter than that of a heat radiation fin nearer to the base
portion.
[0018] A second aspect of the present invention is that one of the
plurality of heat radiation fins may be fixedly attached to the
circuit board and constitute the base portion.
[0019] A third aspect of the present invention is that the contact
portion may be extended from the base portion to form a certain
angle with the base portion, and the plurality of heat radiation
fins may be extended from the contact portion parallel to the base
portion.
[0020] A fourth aspect of the present invention is that a heat
radiation fin spaced from the base portion by more than a
predetermined distance may have a width shorter than that of a heat
radiation fin situated within the predetermined distance.
[0021] A fifth aspect of the present invention is that the
plurality of heat radiation fins each may have a width inversely
proportional to a distance thereof from the base portion.
[0022] A sixth aspect of the present invention is that the
electronic devices may be MOSFETs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] These and other aspects and advantages of the invention will
become apparent and more readily appreciated from the following
description of the exemplary embodiments, taken in conjunction with
the accompanying drawings of which:
[0024] FIG. 1 is a plan view showing a conventional heat sink for
electric devices and a circuit board equipped with the conventional
heat sink;
[0025] FIG. 2 is an exploded perspective view of a PDP assembly
according to an exemplary embodiment of the present invention;
[0026] FIG. 3 is a sectional view of a PDP according to an
exemplary embodiment of the present invention; FIG. 4 is a rear
view of a base panel according to an exemplary embodiment of the
present invention;
[0027] FIG. 5 is a perspective view showing a heat sink and a
circuit board equipped with the heat sink according to exemplary
embodiment of the present invention;
[0028] FIG. 6 is a plan view showing the heat sink and the circuit
board equipped with the heat sink according to an exemplary
embodiment of the present invention;
[0029] FIG. 7 is a plan view showing the heat sink and the circuit
board equipped with the heat sink according to another
illustrative, non-limiting embodiment of the present invention;
and
[0030] FIG. 8 is a graph showing a comparison of the noise
generated by the conventional heat sink and the heat sink of an
exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Reference will now be made in detail to illustrative,
non-limiting embodiments of the present invention, which are
illustrated in the accompanying drawings, wherein like reference
numerals refer to like elements throughout.
[0032] FIG. 2 is an exploded perspective view of a PDP assembly
according to an illustrative, non-limiting embodiment of the
present invention.
[0033] The PDP assembly 10 of the present invention includes a PDP
20 on which images are displayed, a base panel 40 in front of which
the PDP 20 is disposed, and a sheet 30 which is disposed between
the PDP 20 and the base panel 40 to transfer heat.
[0034] As illustrated in FIG. 3, in the PDP 20, a plurality of
partition walls 22 are regularly formed between a pair of glass
substrates 21 provided with an X electrode 21a and a Y electrode
21b, respectively, to form a plurality of pixels 23, and each of
the pixels 23 is sealed with the interior thereof being filled with
high pressure electric discharge gas. Each pixel 23 is provided
with a fluorescent material 24 that emits one of red, green and
blue visible light when ultraviolet rays are irradiated to the
pixel 23. Accordingly, when voltage is applied between the X
electrode 21a and the Y electrode 21b, plasma discharge is
performed through the electric discharge gas in the pixel 23, and
ultraviolet rays are generated. The generated ultraviolet rays
collide with the fluorescent material 24, and consequently visible
rays are generated by the collision between the ultraviolet rays
and the fluorescent material 24.
[0035] Referring to FIG. 4, a variety of electronic devices are
mounted on the back of the base panel 40 to apply voltage to each
pixel 23. For the electronic devices mounted on the back of the
base panel 40, there are a Switched Mode Power Supply (SMPS) 50
that supplies power to the PDP assembly 10 and circuit boards 60a
and 60b that control display by selectively applying and removing
voltage between the X electrode 21a and the Y electrode 21b.
[0036] In this case, the circuit boards 60a and 60b include an X
circuit board 60a that applies voltage to the X electrode 21a of
each pixel 23 and a Y circuit board 60b that applies voltage to the
Y electrode 21b of each pixel 23.
[0037] As shown in FIG. 5, a MOSFET 70 is substantially fabricated
in the form of a plate. A plurality of connection lines 71 are
extended from the MOSFET 70 to be connected to circuit boards 60a
and 60b. The wide surface of the MOSFET 70 is tightly attached to a
heat sink 80 by a fastening means such as a screw so that heat
generated in the MOSFET 70 is transferred to and radiated through
the heat sink 80.
[0038] The heat sink 80 is fixedly attached to the circuit boards
60a and 60b. The heat sink 80 includes a base portion 81 fastened
to the circuit boards 60a and 60b, a contact portion 82 upwardly
extended from the base portion 81 and brought into contact at one
side thereof with the MOSFET 70 to receive heat generated in the
MOSFET 70, and a plurality of heat radiation fins 83a, 83b and 83c
extended from the contact portion 82 to a certain extent, in
parallel with the base portion 81 to radiate heat.
[0039] The base portion 81 of the heat sink 80 is fixedly attached
to the circuit boards 60a and 60b and additionally serves as a heat
radiation fin.
[0040] The heat radiation fins 83a, 83b and 83c are fabricated in
the form of a plate. The plurality of heat radiation fins 83a, 83b
and 83c are arranged in parallel with each other in a vertical
direction, and spaced apart from each other by a certain interval
to desirably radiate heat. In this illustrative, non-limiting
embodiment, the number of the heat radiation fins 83a, 83b and 83c
is three.
[0041] In this case, the uppermost heat radiation fin of the three
heat radiation fins 83a, 83b and 83c is designed to have a width L2
that is smaller than the width L1 of the central and lowermost heat
radiation fins of the three heat radiation fins 83a, 83b and
83c.
[0042] The vibration of a heat radiation fin 83a, 83b or 83c can be
increased in proportion to the distance thereof from the base
portion 81. Additionally, if the heat radiation fins 83a, 83b or
83c vibrate with an amplitude that is greater than a certain
amplitude, air is vibrated and noise is generated. Accordingly,
when the width of the uppermost heat radiation fin 83a is designed
smaller than each of the other heat radiation fins 83b and 83c, the
vibration magnitude of the uppermost heat radiation fin 83a is
reduced to a value that is similar to the vibration magnitude value
for each of the central and lowermost heat radiation fins 83b and
83c.
[0043] The widths of the central and lowermost heat radiation fins
83b and 83c are designed to be the same. The central and lowermost
heat radiation fins 83b and 83c vibrate with amplitudes that are
smaller than the vibration amplitude of the uppermost heat
radiation fin 83c. Therefore, the central and lowermost heat
radiation fins 83b and 83c do not generate noise. Additionally,
they are designed to have the same width in consideration of ease
of fabrication.
[0044] In this illustrative, non-limiting embodiment, the
expressions "upper" and "lower" are used to represent the relative
positions of the elements, but are not used to limit the
configuration of the heat sink 80 in detail.
[0045] Additionally, although in this illustrative, non-limiting
embodiment the number of the heat radiation fins 83a, 83b and 83c
has been described as being three, the number of the heat radiation
fins is not limited to three. Accordingly, after the number of the
heat radiation fins is determined depending upon the overall design
of the heat sink, the widths of the heat radiation fins may be
determined to allow each of the vibration amplitudes of the heat
radiation fins to be less than a certain level, so noise generated
by the heat sink 80 may be reduced to less than a certain
level.
[0046] Furthermore, although in this illustrative, non-limiting
embodiment the central and lowermost heat radiation fins 83b and
83c are designed to have the same width, the widths of the heat
radiation fins 83a, 83b and 83c could be designed to be inversely
proportional to the distances thereof from the base portion 91 as
illustrated in FIG. 7.
[0047] Hereinafter, operations and effects of the heat sink for
electronic devices, and circuit board and PDP assembly, each
equipped with the heat sink are described in detail with reference
to the accompanying drawings.
[0048] A plurality of MOSFETs 70 provided on the X and Y circuit
boards 60a and 60b generate heat and vibration by their on/off
switching operation.
[0049] Generated heat is transmitted to the heat sink 80 and
dissipated to the air through the heat sink 80, so the overheating
of the MOSFETs 70 can be prevented.
[0050] Vibration generated in the MOSFETs 70 along with the heat is
transmitted to the heat sink 80, and the heat radiating fins 83a,
83b and 83c provided in the heat sink 80 are vibrated by the
vibration transmitted from the MOSFET 70.
[0051] In this case, the base portion 81 of the heat sink 80 is
fixedly attached to the circuit boards 60a and 60b, so the heat
radiation fins 83a, 83b or 83c vibrate with a magnitude that is
proportional to the distance between the heat radiation fins 83a,
83b or 83c and the base portion 81 of the heat sink 80.
[0052] Since the width L2 of the uppermost heat radiation fin 83a
that is most distant from the base portion 81 is designed to be
smaller than the width L1 of the central and lowermost heat
radiation fins 83b and 83c, the vibration magnitude of the
uppermost heat radiation fin 83a is rendered similar to the
vibration magnitude of the central and lowermost heat radiation
fins 83b and 83c, as depicted in FIG. 6, thus preventing the
occurrence of noise.
[0053] FIG. 8 is a graph that illustrates the noise of a
conventional heat sink that has three heat radiation fins each with
the same width compared to the noise of the heat sink of the
present invention in which the width L2 of the uppermost fin 83a is
designed to be less than the width L1 of the central and lowermost
fins 83b and 83c.
[0054] In FIG. 8, a solid line represents the experimental values
of the noise of the heat sink 80 of the present invention, while a
dotted line represents the experimental values of the noise of the
conventional heat sink 80.
[0055] As illustrated in portion "A" of FIG. 8, the peak value of
the noise of the heat sink of the present invention is reduced to a
value that is considerably smaller than the peak value of the noise
of the conventional heat sink.
[0056] As described in detail above, when a vibration is
transmitted from the MOSFET, the heat radiation fins of the heat
sink of the present invention are designed to have widths so that
the vibration magnitudes of the heat radiation fins are restricted
to less than a certain level. Accordingly, noise that may be caused
by the vibration can be reduced.
[0057] Furthermore, as the noise generated in the heat sink is
reduced, noise that may be generated in the circuit board and the
PDP panel, each equipped with the heat sink of the present
invention can be reduced.
[0058] Although a few exemplary embodiments of the present
invention have been shown and described, it would be appreciated by
those skilled in the art that changes may be made in these
non-limiting embodiments without departing from the principles and
spirit of the invention, the scope of which is defined in the
claims and their equivalents.
* * * * *