U.S. patent application number 17/101621 was filed with the patent office on 2022-05-26 for heat dissipation for power switches.
The applicant listed for this patent is ABB Schweiz AG. Invention is credited to Slavo Kicin, Fabian Mohn, Giovanni Salvatore.
Application Number | 20220166423 17/101621 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-26 |
United States Patent
Application |
20220166423 |
Kind Code |
A1 |
Salvatore; Giovanni ; et
al. |
May 26, 2022 |
HEAT DISSIPATION FOR POWER SWITCHES
Abstract
Systems, methods, techniques and apparatuses of power switches
are disclosed. One exemplary embodiment is a power switch
comprising an outer housing; a power electronics board disposed
within the housing and including a semiconductor switch structured
to selectively conduct a current between a first power terminal and
a second power terminal; a first heat sink coupled to the power
electronics board; a plurality of thermally conductive connectors;
a second heat sink coupled to the plurality of thermally conductive
connectors, a control electronics board structured to control the
semiconductor switch, the control electronics board being located
within an enclosure formed of the second heat sink, the plurality
of thermally conductive connectors, and the power electronics
board.
Inventors: |
Salvatore; Giovanni;
(Zollikerberg, CH) ; Kicin; Slavo; (Zurich,
CH) ; Mohn; Fabian; (Ennetbaden, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ABB Schweiz AG |
Baden |
|
CH |
|
|
Appl. No.: |
17/101621 |
Filed: |
November 23, 2020 |
International
Class: |
H03K 17/14 20060101
H03K017/14; H05K 7/20 20060101 H05K007/20 |
Claims
1. A power switch comprising: an outer housing including a first
power terminal and a second power terminal; a power electronics
board disposed within the outer housing and including a
semiconductor switch structured to selectively conduct a current
between the first power terminal and the second power terminal; a
first heat sink coupled to a first side of the power electronics
board; a plurality of thermally conductive connectors each
including a first end coupled to a second side of the power
electronics board, the second side of the power electronics board
being opposite the first side of the power electronics board; a
second heat sink coupled to a second end of each of the plurality
of thermally conductive connectors; and a control electronics board
structured to control the semiconductor switch, the control
electronics board being located within an enclosure formed of the
second heat sink, the plurality of thermally conductive connectors,
and the power electronics board.
2. The power switch of claim 1, wherein the power electronics board
includes a direct bonded copper substrate and the control
electronics board including a plurality of components coupled to a
printed circuit board.
3. The power switch of claim 1, wherein the control electronics
board is not in direct contact with the second heat sink or the
plurality of thermally conductive connectors.
4. The power switch of claim 1, wherein the power electronics board
includes a substrate, and the first end of each of the plurality of
thermally conductive connectors are coupled to the substrate.
5. The power switch of claim 1, wherein the control electronics
board and the power electronics board are coupled by way of a
plurality of pin connectors.
6. The power switch of claim 1, wherein a volume of the outer
housing is less than 300 cubic centimeters.
7. The power switch of claim 6, wherein the power switch is
structured to repeatedly toggle the semiconductor switch in
response to determining the power switch is conducting a fault
current, and wherein the first heat sink is not sized to maintain
an internal temperature of the power switch below a semiconductor
switch thermal rating while repeatedly toggling the semiconductor
switch.
8. The power switch of claim 6, wherein the power switch includes a
maximum current rating, and wherein the first heat sink is not
sized to maintain an internal temperature of the power switch below
a semiconductor switch thermal rating while conducting current
equal to the maximum current rating without the second heat
sink.
9. The power switch of claim 1, comprising a second plurality of
thermally conductive connectors coupled between the first heat sink
and the second heat sink.
10. The power switch of claim 1, wherein the second end of each of
the plurality of thermally conductive connectors is coupled to the
second heat sink using solder film, glue, or a screw.
11. A method for constructing a power switch comprising: attaching
a first heat sink to a first side of a power electronics board
including a semiconductor switch structured to selectively conduct
a current between a first power terminal and a second power
terminal, communicatively coupling the power electronics board to a
control electronics board, attaching a plurality of thermally
conductive connectors to a second side of the power electronics
board, attaching the thermally conductive connectors to a second
heat sink, such that the first heat sink, the power electronics
board, and the plurality of thermally conductive connectors form an
enclosure, and disposing the first heat sink, the power electronics
board, and the plurality of thermally conductive connectors, and
the second heat sink within an outer housing, wherein the control
electronics board is located within the enclosure.
12. The method of claim 11, wherein the power electronics board
includes a direct bonded copper substrate and the control
electronics board including a plurality of components coupled to a
printed circuit board.
13. The method of claim 11, wherein the control electronics board
is located not in direct contact with the second heat sink or the
plurality of thermally conductive connectors.
14. The method of claim 11, wherein the power electronics board
includes a substrate, and each of the plurality of thermally
conductive connectors are attached to the substrate.
15. The method of claim 11, wherein the control electronics board
and the power electronics board are coupled by way of a plurality
of pin connectors.
16. The method of claim 11, wherein a volume of the outer housing
is less than 300 cubic centimeters.
17. The method of claim 16, comprising: determining the power
switch is conducting a fault current; and repeatedly toggling the
semiconductor switch, wherein the first heat sink is not sized to
maintain an internal temperature of the power switch below a
semiconductor switch thermal rating while repeatedly toggling the
semiconductor switch.
18. The method of claim 16, wherein the power switch includes a
maximum current rating, and wherein the first heat sink is not
sized to maintain an internal temperature of the power switch below
a semiconductor switch thermal rating while conducting current
having a magnitude of the maximum current rating without the second
heat sink.
19. The method of claim 11, comprising a second plurality of
thermally conductive connectors directly coupled between the first
heat sink and the second heat sink.
20. The method of claim 11, wherein attaching the plurality of
thermally conductive to the second heat sink includes using solder
film, glue, or a screw.
Description
BACKGROUND
[0001] The present disclosure relates generally to heat dissipation
in power switches. Many power systems include power switches
structured to protect power system components from fault currents.
In addition to needing to dissipate heat generated by opening the
power switch, solid state-based power switches have an
on-resistance, causing heat dissipation proportional to the current
conducted by the power switch. Heat generated by the power switch
must be dissipated before the internal temperature of the power
switch exceeds the thermal ratings of the power switch components.
Existing power switches suffer from a number of shortcomings and
disadvantages. There remain unmet needs including reducing thermal
stress on power switches and increasing the current rating of power
switches. For instance, conventional power switch current ratings
and fault mitigation operations are limited by the rate at which
the power switch can dissipate generated heat. In view of these and
other shortcomings in the art, there is a significant need for the
apparatuses, methods, systems and techniques disclosed herein.
DISCLOSURE OF ILLUSTRATIVE EMBODIMENTS
[0002] For the purposes of clearly, concisely and exactly
describing non-limiting exemplary embodiments of the disclosure,
the manner and process of making and using the same, and to enable
the practice, making and use of the same, reference will now be
made to certain exemplary embodiments, including those illustrated
in the figures, and specific language will be used to describe the
same. It shall nevertheless be understood that no limitation of the
scope of the present disclosure is thereby created, and that the
present disclosure includes and protects such alterations,
modifications, and further applications of the exemplary
embodiments as would occur to one skilled in the art with the
benefit of the present disclosure.
SUMMARY OF THE DISCLOSURE
[0003] Exemplary embodiments of the disclosure include systems,
methods, techniques and apparatuses for heat dissipation in power
switches are disclosed. Further embodiments, forms, objects,
features, advantages, aspects and benefits of the disclosure shall
become apparent from the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a cross-section view illustrating an exemplary
power switch.
[0005] FIG. 2 illustrates an exemplary heat sink.
[0006] FIGS. 3A-4B illustrate exemplary outer housings of an
exemplary power switch.
[0007] FIG. 4 is a cross-section view illustrating another
exemplary power switch.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0008] With reference to FIG. 1, there is a block diagram
illustrating an exemplary power switch 100 structured to
selectively conduct a current between a power source and a load. In
certain embodiments, power switch 100 is structured to interrupt
the current during a short circuit fault or another type of fault.
It shall be appreciated that power switch 100 may take the form of
a solid-state circuit breaker, solid-state transfer switch,
solid-state disconnector switch, solid-state tie switch, or another
type of solid-state switch structured to conduct current between a
power source and a load. It shall also be appreciated that power
switch 100 may be implemented in a variety of applications,
including low voltage direct current (DC) systems, medium voltage
DC systems, low voltage alternating current (AC) systems, medium
voltage AC current systems, data centers, vehicular power systems,
or marine power systems, to name but a few examples. In certain
embodiments, low voltage DC may include any voltage less than
1500V; medium voltage DC may include any voltage between 1500V and
50 kV; low voltage AC may include any voltage less than 1000V; and
medium voltage AC may include any voltage between 1000V and 72
kV.
[0009] Power switch 100 includes an outer housing 110, as well as a
power electronics board 120, a control electronics board 160, heat
sinks 130 and 150, a plurality of pin connectors 170, and a
plurality of thermally conductive connectors 140, all disposed
within outer housing 110. Power terminals 111 and 113 of outer
housing 110 are structured to receive and output current conducted
by power switch 100. In certain embodiments, power switch 100 is
structured to conduct bidirectional current, such that power
terminals 111 and 113 both receive and output current. Outer
housing 110 also includes a communication terminal 115 structured
to communicatively couple control electronics board 160 with an
external device, such as a controller or a measuring device. In
certain embodiments, housing 110 does not include communication
terminal 115.
[0010] Power electronics board 120 is structured to selectively
conduct current between power terminals 111 and 113. Board 120
includes a substrate, semiconductor switches 127 and 129, and a
plurality of connectors 128. In the illustrated embodiment, the
substrate of board 120 includes a direct bonded copper (DBC)
substrate including a copper layer 121, a ceramic layer 123, and an
aluminum layer 125. In certain embodiments, ceramic layer 123 may
be replaced by a dielectric layer and aluminum layer 125 may be
replaced with another copper layer. In certain embodiments, the
substrate of board 120 may instead include an active metal braze
substrate, an embedded substrate, an insulated metal substrate, or
a printed circuit board, to name but a few examples.
[0011] Semiconductor switches 127 and 129 may include insulated
gate bipolar transistors (IGBTs), bipolar junction transistors
(BJTs), junction gate field-effect transistors (JFETs), silicon
controlled rectifiers (SCRs), metal-oxide-semiconductor
field-effect transistors (MOSFETs), gate turn-off thyristors
(GTOs), MOS-controlled thyristors (MCTs), integrated
gate-commutated thyristors (IGCTs), silicon carbide (SiC) switches,
or gallium nitride (GaN) switches, to name but a few examples. In
certain embodiments, board 120 includes more or fewer semiconductor
switches. In certain embodiments, board 120 includes semiconductor
switches coupled in series, coupled in parallel, coupled in
anti-parallel, or a combination thereof. For example, board 120 may
include anti-parallel coupled thyristors that are coupled in
parallel with a SiC JFET.
[0012] In the illustrated embodiment, the plurality of connectors
170 couple semiconductor switches 127 and 129 to each other and to
the substrate. In other embodiments, board 120 may include more or
fewer connectors or connectors arranged to connect different
components of board 120.
[0013] The plurality of thermally conductive connectors 140 are
structured to conduct heat between the substrate of board 120 and
heat sink 150. The plurality of thermally conductive connectors 140
are comprised of thermally conductive material such as a metal or
polymer, to name but a few examples. Each thermally conductive
connector includes a first end 141 coupled to copper layer 121 of
the substrate of power electronics board 120, and a second end 143
coupled to heat sink 150.
[0014] In certain embodiments, each of the plurality of thermally
conductive connectors 140 may be a single solid piece or a
plurality of pillars arranged in a row, to name but a few examples.
The plurality of thermally conductive connectors 140 may each have
a width within the range of 0.5 mm-7 mm, a height within the range
of 1 mm-3 cm, and a length equal to or greater than the length of
copper layer 121, to name but a few examples.
[0015] In certain embodiments, the plurality of thermally
conductive connectors 140 and the substrate of power electronics
board 120 are formed as one unit such that a fastener is not
required to couple the plurality of thermally conductive connectors
140 and the substrate of power electronics board 120. In certain
embodiments, the plurality of thermally conductive connectors 140
is coupled to the substrate of power electronics board 120 by way
of solder film, glue, or screws, to name but a few examples. In the
illustrated embodiment, the second ends 143 of the plurality of
thermally conductive connectors 140 are coupled to heat sink 150 by
way of fasteners 151, which may include one or more of thermal
grease, solder film, glue, or screws, to name but a few
examples.
[0016] The plurality of thermally conductive connectors 140 are
sized such that heat sink 150, power electronics board 120, and the
plurality of thermally conductive connectors 140 form an enclosure
large enough for control electronics board 160 to be placed within
the enclosure without components 161 making direct contact with
heat sink 150. In certain embodiments, the enclosure is large
enough that control electronics board 160 is not in contact with
heat sink 150 or the plurality of thermally conductive connectors
140. In the illustrated embodiment, control electronics board 160
is oriented in parallel with the substrate of power electronics
board 120, a base 133 of heat sink 130, and a base 153 of heat sink
150. In other embodiments, control electronics board 160 may be
oriented differently relative to power electronics board 120 within
the enclosure. In the illustrated embodiment, the plurality of
thermally conductive connectors 140 are each oriented perpendicular
to the substrate of power electronics board 120, base 133 of heat
sink 130, and base 153 of heat sink 150, and the control
electronics board 160. In other embodiments, one or more of the
plurality of thermally conductive connectors 140 are oriented
differently relative to power electronics board 120.
[0017] Heat sink 130 is coupled to a first side of power
electronics board 120 opposite semiconductor switches 127 and 129
by way of a thermal grease and preform layer 137. Layer 137 is
comprised of thermally conductive but electrically insulative
material. Layer 137 is structured to eliminate air gaps or spaces
from the interface area between layer 125 of power electronics
board 120 and heat sink 130. In certain embodiments, a thermal
grease and preform layer may be used between heat sink 150 and the
second ends 143 of the plurality of thermally conductive connectors
140. In certain embodiments, power switch 100 does not include
layer 137, and instead uses another type of fastener to couple heat
sink 130 and power electronics board 120, such as solder film,
glue, or screws. In the illustrated embodiment, heat sink 130
extends over the entire width of layer 125. In other embodiments,
heat sink 130 extends over the entire width of the substrate of
power electronics board 120.
[0018] Heat sink 130 is structured to dissipate a portion of the
heat generated by power switch 100 from current conduction and
semiconductor switch operation. However, due to the space and heat
dissipation requirements of power switch 100, heat sink 130 is not
able to dissipate enough of the heat generated by power electronics
board 120 to maintain an internal temperature of power switch 100
below a threshold temperature, above which the internal temperature
of power switch 100 exceeds the thermal ratings of at least one
component of power switch 100. Heat sink 150 is structured to
dissipate another portion of heat generated by power switch 100
from current conduction and semiconductor switch operation. In
certain forms, one or more of heat sinks 130 and 150 may include a
plurality of heat sinks coupled together, forming one heat
sink.
[0019] Heat sinks 130 and 150 are collectively structured to
dissipate heat such that the internal temperature of power switch
100 does not exceed the thermal ratings of any of the components of
power switch 100, such as the thermal ratings for semiconductor
switches 127 and 129, even during fault currents or repetitive
switch toggling. To give another example, power electronics board
120 may be repeatedly toggled, at a frequency greater than 0.5 Hz,
in order to control an electrical characteristic of the conducting
current, such as the current magnitude. In response to determining
power switch 100 is conducting a fault current, control electronics
board 160 may repeatedly toggle semiconductor switches 127 and 129,
generating an amount of heat that the first heat sink is not sized
to dissipate alone while maintaining the internal temperature of
power switch 100 below the thermal ratings of semiconductor
switches 127 and 129.
[0020] It is important to note that if power switch 100 were to
include only one of heat sink 130 and heat sink 150, power switch
100 would not be structured to conduct current up to the maximum
current rating of power switch 100. For example, heat sink 130 is
not sized to dissipate heat so as to maintain an internal
temperature of power switch 100 below a semiconductor switch
thermal rating of switch 127 or 129 while conducting current equal
to the maximum current rating without heat sink 150.
[0021] Heat sinks 130 and 150 may be coupled within power switch
100 by soldering, sintering, gluing, or screwing into place, to
name but a few examples. Heat sinks 130 and 150 may be sized to
cover the whole area of power electronics board 120, or only a
portion of it. For example, heat sinks 130 and 150 may extend
across an entire distance of one dimension of the power electronics
board 120 (e.g. its width), but fail to extend across an entire
distance of another dimension of the power electronics board 120
(e.g. its length).
[0022] Control electronics board 160 is structured to monitor the
current conducted by power switch 100, operate semiconductor
switches 127 and 129 so as to interrupt or regulate the current
conducted by power switch 100, and communicate with measuring
devices of power switch 100 or with another type of external
device. Such monitoring and/or control can occur though
communication terminal 115 or the plurality of pin connectors 170
which may take any variety of forms, including but not limited to a
pin, lead, or other type of conductive device, whether rigid or
flexible such as a flexible connector, that electrically connects
control electronics board 160 to power electronics board 120, to
other locations of power switch 100, or to an external device.
[0023] Control electronics board 160 includes a plurality of
components 161 coupled to a substrate 163. The plurality of
components 161 may include digital circuitry, analog circuitry, or
a combination thereof. For example, the plurality of components 161
may include one or more gate drivers structured to open and close
semiconductor switches 127 and 129.
[0024] Substrate 163 is structured to mechanically support and
interconnect the plurality of components 161. Substrate 163 may
take the form of a printed circuit board, to name but one example.
Substrate 163 may include a variety of arrangements including
single sided (one copper layer), double sided (two copper layers on
both sides of a substrate layer), or multi-layer, to set forth just
a few non-limiting examples. Substrate 163 may be made from a
variety of materials, such as phenolic paper, woven fiberglass,
polyimide foils, and polyimide-fluoropolymer composite foils.
[0025] In the illustrated embodiment, control electronics board 160
is relatively flat having a relatively thin thickness and extending
in a planar fashion. In certain forms, control electronics board
160 may include a variety of cross-sectional shapes as viewed in
the direction of its thickness, including a square, a rectangular,
or another polygonal shape. For example, in the schematic shown in
FIG. 1, the shape of the control electronics board 160 is
rectangular having a width along its larger dimension and a
thickness along its shorter dimension. A length will be appreciated
to extend into the planar view of FIG. 1. In some embodiments, the
printed circuit board can be considered to extend along an elongate
axis (e.g. along its length and/or width), where such elongate axes
are located within the plane of the planar shaped substrate 163.
Although substrate 163 may extend along each of three separate
axes, as shown in the side views of the drawings, an elongate axis
can be considered the axis of extension that includes a larger
dimension than the other axis of extension.
[0026] As will be appreciated in context of the description above,
each of power electronics board 120 and control electronics board
160 include various axes of extension, but it will be understood
that some dimensions of the components include longer axes of
extension as indicated in the drawings. It is the elongate axes of
extension as supported by the drawings that are considered oriented
at angles relative to one another. As can be seen, an elongate axis
of extension of the control electronics board 160 is mounted in
parallel to an elongate axis of extension of the power electronics
board 120. Although control electronics board 160 is shown ordered
above power electronics board 120, in certain forms control
electronics board 160 may be located to the lateral side of power
electronics board 160. In all embodiments though, control
electronics board 160 is not in direct contact with heat sink 150
or the plurality of thermally conductive connectors 140.
[0027] One manner of constructing power switch 100 of any of the
embodiments disclosed herein includes attaching heat sink 130 to a
first side power electronics board 120, communicatively coupling
power electronics board 120 to control electronics board 160,
attaching first ends of the plurality of thermally conductive
connectors 140 to a second side of the power electronics board 120,
and attaching second ends of the thermally conductive connectors
140 to heat sink 150. It shall be appreciated that any or all of
the foregoing features of power switch 100 may also be present in
the other power switches disclosed herein.
[0028] With reference to FIG. 2, there is illustrated an exemplary
heat sink 200 of an exemplary power switch. Features of heat sink
200 described herein are included in other heat sinks described
herein such as heat sinks 130 and 150 of power switch 100 in FIG. 1
and heat sinks 430 and 450 of power switch 400 in FIG. 4.
[0029] Heat sink 200 is structured to conduct heat generated by the
components of power switch 100. Heat sink 200 may be comprised of a
variety of materials using a variety of different manufacturing
processes. For example, heat sink 200 may be comprised of metal or
polymer, to name but a few examples. Heat sink 200 includes a base
201 from which extends a plurality of heat sink fins 202. Heat sink
200 may be made by bonding heat sink fins 202 to a base, folding
fins 202 into shape and bonded, brazed, or soldered to base 201,
stamping fins 202 and encapsulating with a die cast base 201, or
skiving the plurality of fins 202 onto the base 201, to name but a
few examples.
[0030] In the illustrated embodiment, base 201 has consistent
thickness along the length and/or width of heat sink 200, but not
all embodiments of heat sink 200 need include a base of constant
thickness. Thus, base 201 of heat sink 200 may include an elongate
axis of extension, which can be either its length or its width.
Although heat sink 200 may extend along each of three separate
axes, an elongate axis may be considered the axis of extension that
includes a larger dimension than the other axis of extension.
[0031] The plurality of fins 202 may take a variety of forms such
as pins, foils, and columns, to name but a few examples. In this
regard, the plurality of fins 202 can have common cross-sectional
shapes along their respective lengths, but not all embodiments of
heat sink 200 need to have common shapes in all of the fins 202.
Two or more different shapes are also contemplated for the fins
202.
[0032] The plurality of fins 202 may extend to a vertical height
above base 201 of heat sink 200. In certain embodiments, all of the
plurality of fins 202 may extend to a common height above base 201,
but in other forms the plurality of fins 202 may extend to two or
more different heights above base 201.
[0033] In certain forms, the plurality of fins 202 may be spaced
apart equally along a dimension of base 201 (e.g. along its length
and/or width), but not all forms need to include equi-spaced fins.
In certain forms, the plurality of fins 202 may be equi-spaced in
one portion of heat sink 200, while an open space is provided in
another portion of heat sink 200 which is unoccupied by fins.
Furthermore, embodiments of heat sink 200 in one exemplary power
switch need not be made from the same materials and need not be
made using the same manufacturing process. In short, embodiments of
heat sink 200 in one exemplary power switch may be different from
one another.
[0034] With reference to FIGS. 3A and 3B, there are illustrated two
exemplary outer housings 300, 310 for exemplary power switches.
Housing 300 includes a plurality of power terminals 301. Housing
310 including a plurality of power terminals 313 and communication
terminal 311.
[0035] In applications having specific requirements in terms of
space and dimensions, the development of a solid state breaker
involves a challenge to design a device with miniaturized physical
format and able to operate at high currents. Dimensions of the heat
sinks and thermally conductive connectors are such that the
dimensions of the outer housing are minimized to reduce one or more
dimensions of the outer housing or reduce a volume of the outer
housing. The package dimensions include a height, a width, and
depth defined by the outer housing.
[0036] As illustrated in FIG. 3A, outer housing 300 includes a
length of 75 mm, a width of 45 mm, and a depth of 45-90 mm, for a
total volume ranging from 151.875 cubic centimeters to 303.75 cubic
centimeters. In certain embodiments, outer housings 300 and 310
have a volume of less than 300 cubic centimeters.
[0037] With reference to FIG. 4, there is a cross-section view of
an exemplary power switch 400. It shall be appreciated that any or
all of the foregoing features of power switch 100 may also be
present in power switch 400.
[0038] Power switch 400 includes an outer housing 410 including
power terminals 411 and 413, as well as communication terminal 415.
Disposed within outer housing 410, power switch 400 includes power
electronics board 420, heat sink 430, a plurality of thermally
conductive connectors 440, heat sink 450, and control electronics
board 460. Power electronics board 420 and heat sink 430 are
coupled together by thermal grease 431.
[0039] In addition to the above components, which are also
components included in power switch 100 in FIG. 1, power switch 400
includes a second plurality of thermally conductive connectors 480,
each including a first end 481 coupled to heat sink 430, and a
second end 483 coupled to heat sink 450. The second plurality of
thermally conductive connectors 480 are structured to directly
couple heat sink 430 with heat sink 450. It shall be appreciated
that the described features of the thermally conductive connectors
140 in FIG. 1 also apply to the second plurality of thermally
conductive connectors 480. It shall be appreciated that any or all
of the foregoing features of power switch 400 may also be present
in the other power switches disclosed herein.
[0040] Further written description of a number of exemplary
embodiments shall now be provided. One embodiment is a power switch
comprising: an outer housing including a first power terminal and a
second power terminal; a power electronics board disposed within
the outer housing and including a semiconductor switch structured
to selectively conduct a current between the first power terminal
and the second power terminal; a first heat sink coupled to a first
side of the power electronics board; a plurality of thermally
conductive connectors each including a first end coupled to a
second side of the power electronics board, the second side of the
power electronics board being opposite the first side of the power
electronics board; a second heat sink coupled to a second end of
each of the plurality of thermally conductive connectors; and a
control electronics board structured to control the semiconductor
switch, the control electronics board being located within an
enclosure formed of the second heat sink, the plurality of
thermally conductive connectors, and the power electronics
board.
[0041] In certain forms of the foregoing power switch, the power
electronics board includes a direct bonded copper substrate and the
control electronics board including a plurality of components
coupled to a printed circuit board. In certain forms, the control
electronics board is not in direct contact with the second heat
sink or the plurality of thermally conductive connectors. In
certain forms, the power electronics board includes a substrate,
and the first end of each of the plurality of thermally conductive
connectors are coupled to the substrate. In certain forms, the
control electronics board and the power electronics board are
coupled by way of a plurality of pin connectors. In certain forms,
a volume of the outer housing is less than 300 cubic centimeters.
In certain forms, the power switch is structured to repeatedly
toggle the semiconductor switch in response to determining the
power switch is conducting a fault current, and wherein the first
heat sink is not sized to maintain an internal temperature of the
power switch below a semiconductor switch thermal rating while
repeatedly toggling the semiconductor switch. In certain forms, the
power switch includes a maximum current rating, and wherein the
first heat sink is not sized to maintain an internal temperature of
the power switch below a semiconductor switch thermal rating while
conducting current equal to the maximum current rating without the
second heat sink. In certain forms, the power switch comprises a
second plurality of thermally conductive connectors coupled between
the first heat sink and the second heat sink. In certain forms, the
second end of each of the plurality of thermally conductive
connectors is coupled to the second heat sink using solder film,
glue, or a screw.
[0042] Another exemplary embodiment is a method for constructing a
power switch comprising: attaching a first heat sink to a first
side of a power electronics board including a semiconductor switch
structured to selectively conduct a current between a first power
terminal and a second power terminal, communicatively coupling the
power electronics board to a control electronics board, attaching a
plurality of thermally conductive connectors to a second side of
the power electronics board, attaching the thermally conductive
connectors to a second heat sink, such that the first heat sink,
the power electronics board, and the plurality of thermally
conductive connectors form an enclosure, and disposing the first
heat sink, the power electronics board, and the plurality of
thermally conductive connectors, and the second heat sink within an
outer housing, wherein the control electronics board is located
within the enclosure.
[0043] In certain forms of the foregoing method, the power
electronics board includes a direct bonded copper substrate and the
control electronics board including a plurality of components
coupled to a printed circuit board. In certain forms, the control
electronics board is located not in direct contact with the second
heat sink or the plurality of thermally conductive connectors. In
certain forms, the power electronics board includes a substrate,
and each of the plurality of thermally conductive connectors are
attached to the substrate. In certain forms, the control
electronics board and the power electronics board are coupled by
way of a plurality of pin connectors. In certain forms, a volume of
the outer housing is less than 300 cubic centimeters. In certain
forms, the method comprises determining the power switch is
conducting a fault current, repeatedly toggling the semiconductor
switch, wherein the first heat sink is not sized to maintain an
internal temperature of the power switch below a semiconductor
switch thermal rating while repeatedly toggling the semiconductor
switch. In certain forms, the power switch includes a maximum
current rating, and wherein the first heat sink is not sized to
maintain an internal temperature of the power switch below a
semiconductor switch thermal rating while conducting current having
a magnitude of the maximum current rating without the second heat
sink. In certain forms, the method comprises a second plurality of
thermally conductive connectors directly coupled between the first
heat sink and the second heat sink. In certain forms, attaching the
plurality of thermally conductive to the second heat sink includes
using solder film, glue, or a screw.
[0044] While the present disclosure has been illustrated and
described in detail in the drawings and foregoing description, the
same is to be considered as illustrative and not restrictive in
character, it being understood that only certain exemplary
embodiments have been shown and described, and that all changes and
modifications that come within the spirit of the present disclosure
are desired to be protected. It should be understood that while the
use of words such as "preferable," "preferably," "preferred" or
"more preferred" utilized in the description above indicate that
the feature so described may be more desirable, it nonetheless may
not be necessary, and embodiments lacking the same may be
contemplated as within the scope of the present disclosure, the
scope being defined by the claims that follow. In reading the
claims, it is intended that when words such as "a," "an," "at least
one," or "at least one portion" are used there is no intention to
limit the claim to only one item unless specifically stated to the
contrary in the claim. The term "of" may connote an association
with, or a connection to, another item, as well as a belonging to,
or a connection with, the other item as informed by the context in
which it is used. The terms "coupled to," "coupled with" and the
like include indirect connection and coupling, and further include
but do not require a direct coupling or connection unless expressly
indicated to the contrary. When the language "at least a portion"
and/or "a portion" is used, the item can include a portion and/or
the entire item unless specifically stated to the contrary.
* * * * *