U.S. patent application number 12/835298 was filed with the patent office on 2011-02-03 for cooling apparatus for semiconductor component.
This patent application is currently assigned to ADD BLUE CORPORATION LTD.. Invention is credited to Jaewon KIM.
Application Number | 20110024091 12/835298 |
Document ID | / |
Family ID | 43525892 |
Filed Date | 2011-02-03 |
United States Patent
Application |
20110024091 |
Kind Code |
A1 |
KIM; Jaewon |
February 3, 2011 |
COOLING APPARATUS FOR SEMICONDUCTOR COMPONENT
Abstract
Disclosed is a cooling apparatus for a semiconductor component
having a coolant inlet flow path on a coolant flow path connecting
a coolant inlet and a coolant outlet, the coolant inlet flow path
having a diffuser shape, in which its cross-sectional area
increases from a coolant inlet to a portion where cooling fins
start to appear. In the cooling apparatus, the coolant inlet flow
path meets the following equation:
.omega.=D{3/2+sin(.alpha.(x-A))}. Here, .omega. is the radius of
the diffuser, D is the diameter of the coolant inlet, x is a
distance from the coolant inlet toward the cooling fins, .alpha. is
an expansion slope coefficient of the diffuser in radians, and the
sine of (.alpha.A) is 1. In the cooling apparatus for a compact and
integrated semiconductor component, since the diffuser-shaped
coolant inlet flow path extending from the coolant inlet to the
cooling fins is designed in an optimal shape, it is possible to
improve cooling efficiency and to reduce flow resistance to coolant
flow.
Inventors: |
KIM; Jaewon; (Cheonan-si,
KR) |
Correspondence
Address: |
HAMRE, SCHUMANN, MUELLER & LARSON, P.C.
P.O. BOX 2902
MINNEAPOLIS
MN
55402-0902
US
|
Assignee: |
ADD BLUE CORPORATION LTD.
Cheonan-si
KR
|
Family ID: |
43525892 |
Appl. No.: |
12/835298 |
Filed: |
July 13, 2010 |
Current U.S.
Class: |
165/104.33 |
Current CPC
Class: |
H01L 23/473 20130101;
F28F 3/042 20130101; H01L 2924/0002 20130101; F28D 2021/0029
20130101; H01L 2924/0002 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
165/104.33 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 30, 2009 |
KR |
10-2009-0069794 |
Claims
1. A cooling apparatus for a semiconductor component having a
coolant inlet flow path on a coolant flow path connecting a coolant
inlet and a coolant outlet, wherein the coolant inlet flow path has
a diffuser shape, in which its cross-sectional area increases from
a coolant inlet to a portion where cooling fins start to appear,
and meets the following equation: .omega.=D{3/2+sin(.alpha.(x-A))}
in which .omega. is the radius of the diffuser, D is the diameter
of the coolant inlet, x is a distance along the diffuser measured
from the coolant inlet toward the cooling fins, .alpha. is an
expansion slope coefficient of the diffuser in radians, and the
sine of (.alpha.A) is 1.
2. The cooling apparatus according to claim 1, wherein the range of
x is 0.ltoreq.x.ltoreq.6.5D.
3. The cooling apparatus according to claim 1, wherein the range of
A is 3D.ltoreq.A.ltoreq.3.5D and the range of a meets
.pi./7D.ltoreq..alpha..ltoreq..pi./6D.
4. The cooling apparatus according to claim 1, wherein said cooling
fins are grouped to form a heat sink in the coolant flow path.
5. The cooling apparatus according to claim 4, wherein the heat
sink is connected to a semiconductor component corresponding to the
heat sink.
6. A cooling apparatus for a semiconductor component, said cooling
apparatus comprising: a main body comprising a coolant flow path
extending from a coolant inlet to a coolant outlet; and a number of
cooling fins formed in the coolant flow path to cross the coolant
flow path, wherein the coolant flow path comprise a coolant inlet
flow path formed in a diffuser shape of which cross-sectional area
increases from the coolant inlet to a portion where the cooling
fins start to appear and whose profile is a curve.
7. The cooling apparatus according to claim 6, wherein the curve is
a sine function graph shape.
8. The cooling apparatus according to claim 6, wherein said cooling
fins are grouped to form a heat sink in the coolant flow path.
9. The cooling apparatus according to claim 8, wherein the heat
sink is connected to a semiconductor component corresponding to the
heat sink.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a cooling apparatus for
semiconductor components, and more particularly, to a cooling
apparatus for semiconductor components having an optimal coolant
inlet flow path structure capable of improving cooling efficiency
and reducing resistance to coolant flow. This application claims
priority from Korean Patent Application No. 10-2009-0069794 on Jul.
30, 2009 in the Korean Intellectual Property Office (KIPO), the
disclosure of which is incorporated herein by reference in its
entirety.
[0003] 2. Description of the Related Art
[0004] With the recent requirements of compact design and
improvement in the degree of integration of various elements of
electronic components, power consumed by each component increases
and high heat is generated in electronic elements. If heat
generated in a semiconductor component during operation is not
appropriately dissipated, the life time of the component may
decrease while the performance of the component is rapidly
deteriorated, and furthermore, the whole system may become damaged.
Actually, about 70% to 75% of defective of semiconductor components
have been caused by heat.
[0005] Therefore, in order to minimize the problems caused by heat,
it is required maximally dissipate heat generated in various
high-integration semiconductor components. Typical mechanism for
removing heat is a heat-sink having a group of cooling fins is
attached to a semiconductor chip or a ceramic substrate.
[0006] Examples of various variables related to the heat
dissipation performance of a cooling apparatus having a heat sink
include the shape and length of a cooling fin, the area of a
heat-transfer surface of the cooling fin, the inlet geometry of a
coolant and flow field, etc.
[0007] A cooling apparatus for a semiconductor component should be
configured to make a semiconductor component capable of operating
at a predetermined temperature or lower when maximum power is
applied during a predetermined time period after the semiconductor
component reaches temperature saturation by continuous rated power.
To this end, all various variables related to the heat dissipation
performance should be appropriately adjusted.
[0008] In particular, the shape of a coolant inlet flow path is
examined the effects on cooling efficiency and resistance to
coolant flow. Recently, in order to minimize pressure energy loss
of a coolant the inlet geometry of a cooling system is designed in
a diffuser shape. A reverse flow or stall phenomenon depends on a
diffuser divergence angle and whether a diffuser shape is a cone
shape or a straight pipe, which affects the stability degree of
flow.
[0009] In a case of an incompressible fluid, according to the
energy conversion between pressure energy and kinetic energy, a
decrease in a cross-sectional area causes an increase in the
kinetic energy and a decrease in the pressure energy (Bernoulli's
theorem). According to the related art, there is supposed a coolant
inlet flow path structure having a structure in which, in order to
enable coolant flowing into a cooling apparatus for a semiconductor
component to overcome the resistance of cooling fins for heat
transfer in a flow path, the cross-sectional area of the flow path
is enlarged to compensate pressure. However, in this case, since
reserve flow and vortex occurs, the effect is less dominant in
improving cooling efficiency and reducing resistance to coolant
flow. For this reason, it is difficult to form a coolant inlet flow
path having a high cooling efficiency and small resistance to
flow.
[0010] Therefore, in order to improve the heat dissipation
performance of a small-sized high-density semiconductor component,
it is required to develop a coolant inlet flow path structure
improving the cooling efficiency of a cooling apparatus and
reducing resistance to coolant flow.
SUMMARY OF THE INVENTION
[0011] In order to solve the above-mentioned problems, it is an
object of the present invention to provide a cooling apparatus for
a semiconductor component having an optimal coolant inlet flow path
structure capable of improving cooling efficiency and reducing
resistance to coolant flow.
[0012] According to an aspect of the present invention, it is
provided a cooling apparatus for a semiconductor component having a
coolant inlet flow path on a coolant flow path connecting a coolant
inlet and a coolant outlet, the coolant inlet flow path having a
diffuser shape in which its cross-sectional area increases from the
coolant inlet to a portion where cooling fins start to appear. In
the cooling apparatus, the coolant inlet flow path meets the
following equation:
.omega.=D{3/2+sin(.alpha.(x-A))}.
[0013] Here, .omega. is the radius of the diffuser, D is the
diameter of the coolant inlet, x is a distance from the coolant
inlet toward the cooling fins, .alpha. is an expansion slope
coefficient of the diffuser in radians, and the sine of (.alpha.A)
is 1.
[0014] The range of x may be 0.ltoreq.x.ltoreq.6.5D.
[0015] Further, the range of A may be 3D.ltoreq.A.ltoreq.3.5D and
the range of a may meet .pi./7D.ltoreq..alpha..ltoreq..pi./6D.
[0016] A number of cooling fins may be grouped to form a heat sink
in the coolant flow path.
[0017] The heat sink may be connected to a semiconductor component
corresponding to the heat sink.
[0018] According to another aspect of the present invention, it is
provided a cooling apparatus for a semiconductor component
including: a main body comprising a coolant flow path extending
from a coolant inlet to a coolant outlet; and a number of cooling
fins formed in the coolant inlet flow path to cross the coolant
flow path. In this cooling apparatus, the coolant flow path
includes a coolant inlet flow path formed in a diffuser shape whose
cross-sectional area increases from the coolant inlet to a portion
where the cooling fins start to appear and whose profile is a
curve.
[0019] The curve may be a sine function graph shape.
[0020] A number of cooling fins may be grouped to form a heat sink
in the coolant flow path.
[0021] The heat sink may be connected to a semiconductor component
corresponding to the heat sink.
[0022] In the cooling apparatus for compact and integrated
semiconductor components according to the embodiment of the present
invention, since the diffuser-shaped coolant inlet flow path
extending from the coolant inlet to the cooling fins is designed in
an optimal shape, it is possible to improve cooling efficiency and
to reduce resistance to coolant flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a perspective view schematically illustrating a
cooling apparatus for semiconductor components according to an
exemplary embodiment of the present invention;
[0024] FIG. 2 is a planar cross-sectional view illustrating the
internal of the cooling apparatus shown in FIG. 1;
[0025] FIG. 3 is a drawing illustrating a variation in a flow field
in cases (a) and (b) of where the coolant inlet flow path CP has
different curved expanding pipe shapes;
[0026] FIG. 4 is a drawing illustrating a variation in a flow field
in cases (a) and (b) of where the coolant inlet flow path CP has
different linear expanding pipe shapes;
[0027] FIG. 5 is a drawing illustrating a temperature distribution
around individual heat sinks when the shape of the coolant inlet
flow path CP is a curved expanding pipe;
[0028] FIG. 6 is a drawing illustrating a temperature distribution
around individual heat sinks when the shape of the coolant inlet
flow path CP is a linear expanding pipe;
[0029] FIG. 7 is a plot illustrating temperature variations during
a time period when the maximum continuous rated power is applied to
comparison examples having various shapes of the coolant inlet flow
paths; and
[0030] FIG. 8 is a plot illustrating an equation representing the
shape of the coolant inlet flow path CP according to the exemplary
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] Hereinafter, exemplary embodiments of the present invention
will be described with reference to the accompanying drawings.
[0032] FIG. 1 is a perspective view schematically illustrating a
cooling apparatus for semiconductor components according to an
exemplary embodiment of the present invention. FIG. 2 is a planar
cross-sectional view illustrating the internal of the cooling
apparatus in shown FIG. 1. As shown in the drawings, a cooling
apparatus 100 has a coolant inlet 120 formed on one side of a main
body 110, an coolant outlet 130 formed on another side of the main
body 110, and a coolant flow path 125 connecting the coolant inlet
120 and the coolant outlet 130. A number of semiconductor
components 140 are attached to the top surface of the main body
110.
[0033] Inside the main body 110, as shown in FIG. 2, a coolant flow
path 125 is formed to extend from the coolant inlet 120 to the
coolant outlet 130. In the coolant flow path 125, there are
provided a number of heat sinks H1, H2, H3, H4, H5, and H6
including cooling fin groups. Each of the cooling fin groups is
composed of a number of cooling fins F which are provided to cross
the coolant flow path 125 and are connected to the semiconductor
components 140. The coolant flow path comprise a coolant inlet flow
path CP having a diffuser shape, in which its cross-sectional area
increases from the coolant inlet to a portion where cooling fins F
of the heat sink H1 (hereinafter, referred to as a first heat sink)
start to appear.
[0034] Meanwhile, a difference in heat dissipation performance
according to whether the shape of the coolant inlet flow path CP is
a curved expanding pipe or a linear expanding pipe occurs. The
difference will be described below in detail.
[0035] FIG. 3 is a drawing illustrating a variation in a flow field
in cases (a) and (b) of where the coolant inlet flow path CP has
different curved expanding pipe shapes. FIG. 3 shows a flow field
in a case of (a) where the ratio of a measurement location y to the
diameter H.sub.hs (=22.5 mm) of a portion of the coolant flow path
125 where the heat sink H1 is positioned, that is, y/H.sub.hs is
0.3, and a flow field in a case of (b) where the ratio of the
measurement location y to the diameter H.sub.hs (=22.5 mm) of the
portion of the coolant flow path 125 where the heat sink H1 is
positioned, that is, y/H.sub.hs is 0.7. Here, the measurement
location y represents a distance from the top surface of the heat
sink H1, having the cooling fins F attached thereto, to the bottom
of the heat sink H1.
[0036] As shown in FIG. 3, when the ratio y/H.sub.hs is 0.3, the
flow field is uniformly generated; however, when the ratio
y/H.sub.hs is 0.7, a reserve flow phenomenon occurs in a wide range
from a portion where cooling fins F start to appear to the
inlet.
[0037] FIG. 4 is a drawing illustrating a variation in a flow field
in cases (a) and (b) of where the coolant inlet flow path CP has
different linear expanding pipe shapes. FIG. 4 shows a flow field
in a case of (a) where the ratio of a measurement location y to the
diameter H.sub.hs (=22.5 mm) of the portion of the coolant flow
path 125 where the heat sink H1 is positioned, that is, y/H.sub.hs
is 0.3, and a flow field in a case of (b) where the ratio of the
measurement location y to the diameter H.sub.hs (=22.5 mm) of the
portion of the coolant flow path 125 where the heat sink H1 is
positioned, that is, y/H.sub.hs is 0.7. Similarly, the measurement
location y represents a distance from the top surface of the heat
sink H1, having the cooling fins F attached thereto, to the bottom
of the heat sink H1.
[0038] Referring to FIG. 4, when the shape of the coolant inlet
flow path CP is a linear expanding pipe, vortex is formed partially
between the cooling fins F, in particular, in a portion where
cooling fins F start to appear; however, reserve flow is not formed
when the ratio y/H.sub.hs is 0.3 or 0.7.
[0039] As shown in the cases (a) and (b) of FIG. 3, when the shape
of the coolant inlet flow path CP is a curved expanding pipe, heat
energy generated by a heat emission element can be effectively
removed through circulating flows caused by the occurrence of
vortex or reserve flow.
[0040] This difference in the heat-transfer performance according
to the shape of the coolant inlet flow path CP will be described in
more detail.
[0041] FIG. 5 is a drawing illustrating a temperature distribution
around individual heat sinks H1, H2, H3, H4, H5, and H6 provided in
a coolant flow path 125 of a cooling apparatus when the shape of
the coolant inlet flow path CP is a curved expanding pipe. FIG. 6
is a drawing illustrating a temperature distribution around
individual heat sinks H1, H2, H3, H4, H5, and H6 provided in a
coolant flow path 125 of a cooling apparatus when the shape of the
coolant inlet flow path CP is a linear expanding pipe. In FIGS. 5
and 6, numerical values inside the heat sinks represent
temperatures (.degree. C.).
[0042] As easily seen from the temperature distributions shown in
FIGS. 5 and 6, the temperatures around the individual heat sinks
when the shape of the coolant inlet flow path CP is a curved
expanding pipe are lower than those when the shape of the coolant
inlet flow path CP is a linear expanding pipe.
[0043] The following Table 1 shows a cooling performance comparison
between the case where the shape of the coolant inlet flow path CP
is a curved expanding pipe and the case where the shape of the
coolant inlet flow path CP is a linear expanding pipe.
[0044] Numerical values in Table 1 are checked results on whether a
temperature of a power semiconductor component is equal to or lower
than a target temperature (120.degree. C.) due to heat dissipation
on a first condition that the maximum rated power is applied 30
seconds after a power semiconductor component of an IGBT
(integrated gate bipolar transistor module for MCU (motor control
unit) and HDC (high side DC/DC converter) reaches temperature
saturation by continuous rated power and on a second condition that
electrical energy exceeding maximum rated power by 30% is applied
30 seconds after a power semiconductor component of an IGBT module
for MCU (motor control unit) and HDC (high side DC/DC converter)
reaches temperature saturation by continuous rated power. Here, the
IGBT module is a power module of a driving system mounted a 40 kw
diesel engine-motor hybrid electrical vehicle (HEV).
TABLE-US-00001 TABLE 1 First condition Second condition Shape of
coolant inlet flow path (.degree. C.) (.degree. C.) Curved
expanding pipe 99.4 111.75 Linear expanding pipe 103.24 117.38
[0045] Referring to Table 1, when the shape of the coolant inlet
flow path CP is a curved expanding pipe, the coolant inlet flow
path CP is at temperatures remarkably lower than the target
temperature (120.degree. C.) due to heat dissipation on both of the
first and second conditions and also has the highest temperature
remarkably lower than when the shape of the coolant inlet flow path
CP is a linear expanding pipe.
[0046] Moreover, it can be verified that the case where the shape
of the coolant inlet flow path CP is a curved expanding pipe is
much more effective than the case where the shape of the coolant
inlet flow path CP is a linear expanding pipe in that an error
between a result obtained by fabricating a trial product and
performing performance estimation and a temperature distribution of
an actual product is about maximum 7% and design considering a
safety factor is inevitable in the case where the shape of the
coolant inlet flow path CP is a linear expanding pipe.
[0047] In the exemplary embodiment of the present invention,
considering the case where the shape of the coolant inlet flow path
CP is a curved expanding pipe is much more effective than the case
where the shape of the coolant inlet flow path CP is a linear
expanding pipe, curved expanding pipes having various curve
profiles have been formed and their effects have been verified.
[0048] FIG. 7 is a graph illustrating temperature variations during
a time period when the maximum continuous rated power is applied
after a power semiconductor component of an IGBT module for MCU
(motor control unit) and HDC (high side DC/DC converter), which is
a power module of a driving system, reaches temperature saturation
by continuous rated power, in comparison examples having various
shapes of coolant inlet flow paths CP.
[0049] In the drawing, first to fifth comparison examples represent
cases where the profiles of coolant inlet flow paths CP are a
linear function graph shape, a cosine function graph shape, an
ellipse function graph shape, a sine function graph shape, and a
parabolic function graph shape, respectively. As can be seen from
the test results, the fourth comparison example in which the
profile of the coolant inlet flow path CP is a sine function graph
shape has the lowest pressure resistance and the highest cooling
performance.
[0050] As described above, considering that the coolant inlet flow
path CP having a curved expanding pipe shape has better cooling
performance and the profile of a sine function graph shape has the
lowest pressure resistance and the highest cooling performance, in
the embodiment of the present invention, the shape of the coolant
inlet flow path CP is limited as follows.
[0051] When w is the radius of the diffuser, D is the diameter of
the coolant inlet, x is a distance from the coolant inlet toward
the cooling fins, a is an expansion slope coefficient of the
diffuser in radians, and the sine of (.alpha.A) is 1; the shape of
the coolant inlet flow path CP according to the embodiment of the
present invention is determined to be a shape meeting the following
Equation 1. When the sine of (.alpha.A) is 1, `A` means an x value
of an inflexion point in a sine function appearing in Equation
1.
.omega.=D{3/2+sin(.alpha.(x-A))} [Equation 1]
[0052] In Equation 1, x meets 0.ltoreq.x.ltoreq.6.5D and `A` meets
3D.ltoreq.A.ltoreq.3.5D.
[0053] Specifically, the shape of the coolant inlet flow path CP
greatly varies according to the `A` value (the location of the
inflexion point). At this time, when the `A` value is small, the
cross-sectional area of the flow path may be rapidly enlarged, and
when the `A` value is large, the cross-sectional area of the flow
path may be enlarged at a location too far from the coolant inlet.
For this reason, it is required to appropriately select the `A`
value.
[0054] In the embodiment of the present invention, the `A` value is
designed in a range of 3D.ltoreq.A.ltoreq.3.5D. In this case,
.alpha. meets .pi./7D.ltoreq..alpha..ltoreq..pi./6D.
[0055] Specifically, in a first case of A=3D, sin(.alpha.A)=1 can
be written as sin(.alpha.3D)=1 and thus .alpha.3D becomes .pi./2.
As a result, a becomes .pi./6D. In a second case of A=3.5D,
sin(.alpha.A)=1 can be written as sin(.alpha.3.5D)=1 and thus
.alpha.3.5D becomes .pi./2. As a result, .alpha. becomes .pi./7D.
Considering this point, a has the range of
.pi./7D.ltoreq..alpha..ltoreq..pi./6D.
[0056] In the present invention, experiments on differences in
cooling performance was conducted on a condition that the range of
x was set to 0.ltoreq.x.ltoreq.6.5D to define the upper and lower
limits thereof.
[0057] The following Table 2 shows a cooling performance comparison
according to upper and lower limits of x. Numerical values in Table
2 are checked results on whether a temperature of a power
semiconductor component is equal to or lower than a target
temperature (120.degree. C.) due to heat dissipation on the first
condition that the maximum rated power is applied 30 seconds after
a power semiconductor component of an IGBT module for MCU (motor
control unit) and HDC (high side DC/DC converter) reaches
temperature saturation by continuous rated power and on the second
condition that electrical energy exceeding the maximum rated power
by 30% is applied 30 seconds after a power semiconductor component
of an IGBT module for MCU (motor control unit) and HDC (high side
DC/DC converter) reaches temperature saturation by continuous rated
power. Here, the IGBT module is a power module of a driving system
mounted a 40 kw diesel engine-motor hybrid electrical vehicle
(HEV).
TABLE-US-00002 TABLE 2 Lower/upper First condition Second condition
limits of x (.degree. C.) (.degree. C.) Inventive example 0/6.5D
99.4 111.75 First experimental 0/7D 103.09 117.51 example Second
experimental 0/6D 103.83 118.59 example Third experimental 0/7.5D
101.92 117.38 example
[0058] Referring to Table 2, the inventive example having x in a
range of 0.ltoreq.x.ltoreq.6.5D is at temperatures remarkably lower
than the target temperature (120.degree. C.) due to heat
dissipation on both of the first and second conditions, as compared
with the first to third experimental examples. Therefore, it can be
seen that the cooling performance of the inventive example is the
most effective.
[0059] Moreover, it can be verified that cooling performance is the
most superior when the range of x in a range of
0.ltoreq.x.ltoreq.6.5D in that an error between a result obtained
by fabricating a trial product and performing performance
estimation and a temperature distribution of an actual product is
about maximum 7% and thus design considering a safety factor is
inevitable in the cases of the first to third experimental
examples.
[0060] Although the embodiments of the present invention have been
described above with reference to the accompanying drawings, they
are used in a generic and descriptive sense only and not for
purposes of limitation. It will be apparent to those skilled in the
art that modifications and variations can be made in the present
invention without deviating from the spirit or scope of the
invention.
* * * * *