U.S. patent application number 10/846011 was filed with the patent office on 2004-12-30 for thermal transfer container for semiconductor component.
This patent application is currently assigned to Wetherill Associates, Inc.. Invention is credited to Lasek, John P., Mai, Toan Van, Malanga, Robert, Nguyen, An Huu, Oropeza, Frank C., Oropeza, Frank W..
Application Number | 20040263007 10/846011 |
Document ID | / |
Family ID | 33479296 |
Filed Date | 2004-12-30 |
United States Patent
Application |
20040263007 |
Kind Code |
A1 |
Malanga, Robert ; et
al. |
December 30, 2004 |
Thermal transfer container for semiconductor component
Abstract
A thermal transfer container is disclosed for a semiconductor
component to transfer heat to a heat sink such as used in
rectifiers for alternators. The thermal transfer container includes
an outer cylindrical surface having threads that engage threads
defined in the heat sink bore for electrically and thermally
connecting the metallic cylindrical container to the heat sink.
Inventors: |
Malanga, Robert; (Lake Mary,
FL) ; Lasek, John P.; (Port Orange, FL) ;
Nguyen, An Huu; (Orlando, FL) ; Mai, Toan Van;
(Orlando, FL) ; Oropeza, Frank C.; (Apopka,
FL) ; Oropeza, Frank W.; (Apopka, FL) |
Correspondence
Address: |
RICHARD K. WARTHER
ALLEN, DYER,DOPPELT,MILBRATH & GILCHRIST P.A.
1401 CITRUS CENTER 255 SOUTH ORANGE AVENUE
P.O. BOX 3791
ORLANDO
FL
32802-3791
US
|
Assignee: |
Wetherill Associates, Inc.
Royersford
PA
|
Family ID: |
33479296 |
Appl. No.: |
10/846011 |
Filed: |
May 14, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60471662 |
May 19, 2003 |
|
|
|
Current U.S.
Class: |
310/52 ;
257/E23.104; 257/E25.026 |
Current CPC
Class: |
H01L 2924/12043
20130101; H02K 11/046 20130101; H01L 25/115 20130101; H01L 2924/14
20130101; H01L 2224/01 20130101; H01L 23/3675 20130101; H01L 24/01
20130101; H01L 2924/12043 20130101; H01L 2924/00 20130101; H01L
2924/14 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
310/052 |
International
Class: |
F25B 021/02 |
Claims
1. A thermal transfer container for a semiconductor component for
transferring heat to a heat sink having a threaded heat sink bore
defined in the heat sink comprising: a cylindrical container having
a cylindrical surface extending between a first and a second
cylindrical end; a first end wall closing said first end of said
cylindrical container; a first connector for electrically and
thermally connecting a first terminal of the semiconductor
component to said first end wall of the cylindrical container; a
second connector affixing an electrical lead to a second terminal
of the semiconductor component with said electrical lead extending
from said second cylindrical end of said cylindrical container; and
cylindrical threads disposed about said cylindrical surface of said
cylindrical container for threadably engaging with said threaded
heat sink bore of the heat sink for electrically and thermally
connecting the cylindrical container to the heat sink.
2. A thermal transfer container as set forth in claim 1, wherein
said cylindrical container is a metallic container.
3. A thermal transfer container as set forth in claim 1, wherein
said cylindrical container is a metallic copper container.
4. A thermal transfer container as set forth in claim 1, wherein
said first end wall is integrally formed with said first end of
said cylindrical container as a one piece unit.
5. A thermal transfer container as set forth in claim 1, wherein
said first connector comprises a first metallic connector for
directly electrically and thermally connecting said first terminal
of the semiconductor component to an interior surface of said first
end wall of the cylindrical container.
6. A thermal transfer container as set forth in claim 1, wherein
said second connector comprises a second metallic connector for
directly electrically affixing an electrical lead to said second
terminal of the semiconductor component with said electrical lead
extending from said second cylindrical end of said cylindrical
container.
7. A thermal transfer container as set forth in claim 1, wherein
said first connector comprises a first solder connector for
directly electrically and thermally connecting said first terminal
of the semiconductor component to an interior surface of said first
end wall of the cylindrical container; and a second solder
connector for directly electrically affixing an electrical lead to
said second terminal of the semiconductor component with said
electrical lead extending from said second cylindrical end of said
cylindrical container.
8. A thermal transfer container as set forth in claim 1, wherein
said first end wall extends radially outward from said cylindrical
sidewall to form a radial flange for electrically and thermally
contacting the heat sink when said cylindrical threads of said
cylindrical container are threadably engaged with said threaded
heat sink bore of the heat sink for providing enhanced electrical
and thermal conduction with the heat sink.
9. A thermal transfer container as set forth in claim 1, wherein
said first end wall extends radially outward from said cylindrical
sidewall to form a radial flange for electrically and thermally
contacting a counterbore in the heat sink when said cylindrical
threads of said cylindrical container are threadably engaged with
said threaded heat sink bore of the heat sink for providing
enhanced electrical and thermal conduction with the heat sink.
10. A thermal transfer container as set forth in claim 1, wherein
said semiconductor component is directly electrically and thermally
connected to an interior surface of said first end wall.
11. A thermal transfer container as set forth in claim 1, wherein
said cylindrical threads engaging with said threaded heat sink bore
enables said cylindrical container to be unscrewed from the
threaded heat sink bore to replace a cylindrical container having a
defective semiconductor component.
12. A thermal transfer container as set forth in claim 1, including
a recess defined in an exterior surface of said first end wall for
matingly receiving a tool for rotating said cylindrical container
relative to said threaded heat sink bore of the heat sink.
13. A thermal transfer container for a semiconductor component for
transferring heat to a heat sink having a threaded heat sink bore
defined in the heat sink comprising: a cylindrical container having
a cylindrical surface extending between a first and a second
cylindrical end; a first end wall closing said first end of said
cylindrical container extending radially outward to form a radial
flange; a first connector for electrically and thermally connecting
a first terminal of the semiconductor component to said first end
wall of the cylindrical container; a second connector affixing an
electrical lead to a second terminal of the semiconductor component
with said electrical lead extending from said second cylindrical
end of said cylindrical container; and cylindrical threads disposed
about said cylindrical surface of said cylindrical container for
threadably engaging with said threaded heat sink bore of the heat
sink for electrically and thermally connecting the cylindrical
container to the heat sink with said radial flange electrically and
thermally contacting the heat sink for providing enhanced
electrical and thermal conduction with the heat sink.
14. A thermal transfer container as set forth in claim 13, wherein
said first end wall including said radial flange is integrally
formed with said first end of said cylindrical container as a one
piece unit.
15. A thermal transfer container as set forth in claim 13, wherein
said radial flange electrically and thermally contacts a
counterbore in the heat sink when said cylindrical threads of said
cylindrical container are threadably engaged with said threaded
heat sink bore of the heat sink for providing enhanced electrical
and thermal conduction with the heat sink.
16. A thermal transfer container as set forth in claim 13, wherein
said cylindrical threads engaging with said threaded heat sink bore
enables said cylindrical container to be unscrewed from the
threaded heat sink bore to replace a cylindrical container having a
defective semiconductor component.
17. A thermal transfer container as set forth in claim 13,
including a recess defined in an exterior surface of said first end
wall for matingly receiving a tool for rotating said cylindrical
container relative to said threaded heat sink bore of the heat
sink.
18. In an alternator for generating electricity upon rotation of a
rotor within a stator, the alternator having a rectifier that
includes heat sinks each having a heat sink bore that receives a
metallic cylindrical container having a semiconductor component
having a first terminal of the semiconductor component being
electrically connected to a first end of the metallic cylindrical
container and a second terminal of the semiconductor component
extending from a second end of the metallic cylindrical container,
the improvement comprising: threads defined in the heat sink bore;
and the cylindrical container having threads disposed about an
outer cylindrical surface of the metallic cylindrical container for
threadably engaging with the threaded heat sink bore of the heat
sink bore for electrically and thermally connecting the metallic
cylindrical container to the heat sink.
19. A thermal transfer container as set forth in claim 18, wherein
said cylindrical container is a metallic container.
20. A thermal transfer container as set forth in claim 18, wherein
said cylindrical container is a metallic copper container.
21. A thermal transfer container as set forth in claim 18, wherein
said first connector comprises a first metallic connector for
directly electrically and thermally connecting said first terminal
of the semiconductor component to an interior surface of said first
end wall of the cylindrical container.
22. A thermal transfer container as set forth in claim 18, wherein
said second connector comprises a second metallic connector for
directly electrically affixing an electrical lead to said second
terminal of the semiconductor component with said electrical lead
extending from said second cylindrical end of said cylindrical
container.
23. A thermal transfer container as set forth in claim 18, wherein
said first connector comprises a first solder connector for
directly electrically and thermally connecting said first terminal
of the semiconductor component to an interior surface of said first
end wall of the cylindrical container; and a second solder
connector for directly electrically affixing an electrical lead to
said second terminal of the semiconductor component with said
electrical lead extending from said second cylindrical end of said
cylindrical container.
24. A thermal transfer container as set forth in claim 18, wherein
said first end wall extends radially outward from said cylindrical
sidewall to form a radial flange for electrically and thermally
contacting the heat sink when said cylindrical threads of said
cylindrical container are threadably engaged with said threaded
heat sink bore of the heat sink for providing enhanced electrical
and thermal conduction with the heat sink.
25. A thermal transfer container as set forth in claim 18, wherein
said semiconductor component is directly electrically and thermally
connected to an interior surface of said first end wall.
26. A thermal transfer container as set forth in claim 18, wherein
said cylindrical threads engaging with said threaded heat sink bore
enables said cylindrical container to be unscrewed from the
threaded heat sink bore to replace a cylindrical container having a
defective semiconductor component.
27. A thermal transfer container as set forth in claim 18,
including a recess defined in an exterior surface of said first end
wall for matingly receiving a tool for rotating said cylindrical
container relative to said threaded heat sink bore of the heat
sink.
28. A rectifier assembly comprising: negative and positive heat
sink plates spaced from each other, each having threaded diode
receiving orifices; positive and negative diode assemblies threaded
into the respective threaded orifices of positive and negative heat
sink plates; and an insulator separating the respective negative
and positive heat sink plates.
29. A rectifier assembly according to claim 28, wherein each diode
assembly comprises a cylindrical container and semiconductor diode
received therein, and threads formed on the cylindrical container.
Description
RELATED APPLICATIONS
[0001] This application is based upon prior filed copending
provisional application Ser. No. 60/471,662 filed May 19, 2003.
FIELD OF THE INVENTION
[0002] This invention relates to solid state electrical devices and
more particularly to an improved thermal transfer container for a
semiconductor component for transferring heat to a heat sink.
BACKGROUND OF THE INVENTION
[0003] Semiconductor components such as diodes, transistors,
integrated circuits and the like generate heat during normal
operation. Most semiconductor components are thermally coupled to
transfer heat to a heat sink for dissipating the heat generated by
the semiconductor component. Some semiconductor components are
coupled through a thermal transfer container to a heat sink. The
thermal transfer container transfers heat generated by the
semiconductor component to the heat sink.
[0004] One specific use application for a semiconductor diode
component is the use in electrical generating equipment such as
electrical alternators and the like. In an electrical alternator, a
rotor rotates within a stator for generating alternating current
(AC) power. Many electrical alternators are used to provide direct
current (DC) power to a DC power system. When (DC) power is
required, semiconductor diodes are used to rectify alternating
current (AC) power into direct current (DC) power.
[0005] A very popular type of AC to DC system is found in ignition
systems in various types of land vehicles, aircraft, and sea
vessels. These AC to DC generating systems use a plurality of
diodes arranged as an alternator rectifier unit. An alternator
rectifier unit comprises a plurality of diodes installed in a
positive and a negative heat sink configuration that is welded into
a frame to form the alternator rectifier unit.
[0006] One traditional method of manufacturing the alternator
rectifier unit comprises the use of a semiconductor diode in the
form of a silicone glass passivated wafer. The semiconductor diode
wafer was located within a thermal transfer container commonly
referred to as a diode cup.
[0007] The thermal transfer container was in the general form of a
cup having been formed by a cylindrical container having a first
end closed by an end wall. A first side of the semiconductor diode
wafer was affixed to the end wall of the thermal transfer
container. An electrical lead was connected to a second side of the
semiconductor diode to extend from the open end of the cylindrical
container. An epoxy material filled the cylindrical container to
secure the semiconductor diode wafer within the thermal transfer
container.
[0008] The thermal transfer container was provided with a series of
knurls extending about the outer cylindrical surface of the thermal
transfer container. The knurls enabled the thermal transfer
container including the semiconductor diode to be pressed fitted
into an aperture of a heat sink. The knurls of the thermal transfer
container engaged with the aperture of a heat sink for electrically
and thermally connecting the cylindrical container to the heat
sink. Although these alternator rectifier units have found wide
spread use in the art, these alternator rectifier units suffered
from several disadvantages.
[0009] Semiconductor diodes in the form of a silicone glass
passivated wafer are susceptible to damage during the press fit
operation. Damage to only one of the semiconductor diodes results
in an electrical failure of the entire alternator rectifier unit.
Since most of the alternator rectifier units were welded into a
unit, the failure of only one diode renders the entire alternator
rectifier unit inoperative with no present method to replace a
failed diode in an alternator rectifier unit.
[0010] Only the peaks of the knurls of the thermal transfer
container engaged with the aperture of a heat sink for electrically
and thermally connecting the cylindrical container to the heat
sink. Since only the peaks of the knurls engaged with the aperture
of the heat sink, only about fifty percent (50%) of the thermal
transfer container actually engages the heat sink.
[0011] Accordingly, the thermal transfer containers of the prior
art exhibited only adequate electrical and thermal connection of
the cylindrical container to the heat sink.
[0012] Some prior art proposals have attempted to provide a
solution for installing semiconductor components to a heat sink.
These proposals include disclosures found in U.S. Pat. Nos.
2,790,940; 2,820,929; 3,025,435; 3,033,537; 3,176,201; 3,182,117;
3,218,524; 3,229,756; 3,480,844; 3,713,007; 3,946,416; 4,607,685;
5,313,099; 5,703,395; 5,789,813; 6,021,045; 6,455,929; and
6,476,527. None of these proposals have solved the problems
identified above, especially regarding alternator rectifiers.
SUMMARY OF THE INVENTION
[0013] Therefore, it is an object of the present invention to
provide an improved thermal transfer container for a semiconductor
component for transferring heat to a heat sink with enhanced
electrical and thermal conductivity between the semiconductor
component and the heat sink.
[0014] Another object of this invention is to provide an improved
thermal transfer container for a semiconductor component that
provides a consistent electrical and thermal conductivity between
the semiconductor components and heat sinks in a manufacturing
process.
[0015] Another object of this invention is to provide an improved
thermal transfer container for a semiconductor component that may
be readily removed from the heat sink for replacing a defective
semiconductor component.
[0016] Another object of this invention is to provide an improved
thermal transfer container for a semiconductor component that does
not appreciably add to the cost of the thermal transfer container
relative to the thermal transfer containers of the prior art.
[0017] The present invention relates to an improved thermal
transfer container for a semiconductor component for transferring
heat to a heat sink such as heat sink plates of automotive
alternators. A threaded heat sink bore is defined in a heat sink. A
cylindrical container has a cylindrical surface extending between a
first and a second cylindrical end. A first end wall closes the
first end of the cylindrical container. A first connector
electrically and thermally connects a first terminal of the
semiconductor component to the first end wall of the cylindrical
container. A second connector affixes an electrical lead to a
second terminal of the semiconductor component with the electrical
lead extending from the second cylindrical end of the cylindrical
container. Cylindrical threads are disposed about the cylindrical
surface of the cylindrical container for threadably engaging with
the threaded heat sink bore of the heat sink for electrically and
thermally connecting the cylindrical container to the heat
sink.
[0018] In a more specific example of the invention, the cylindrical
container is a metallic container such as a metallic copper
container. Preferably, the first end wall is integrally formed with
the first end of the cylindrical container as a one-piece unit.
[0019] The first connector comprises a first metallic connector for
directly electrically and thermally connecting the first terminal
of the semiconductor component to an interior surface of the first
end wall of the cylindrical container. The second connector
comprises a second metallic connector for directly electrically
affixing an electrical lead to the second terminal of the
semiconductor component with the electrical lead extending from the
second cylindrical end of the cylindrical container. In one
example, the first and second metallic connectors comprise a first
and second solder connectors.
[0020] In one example of the invention, the first end wall extends
radially outward from the cylindrical sidewall to form a radial
flange for electrically and thermally contacting the heat sink when
the cylindrical threads of the cylindrical container are threadably
engaged with the threaded heat sink bore of the heat sink for
providing enhanced electrical and thermal conduction with the heat
sink.
[0021] The cylindrical threads engaging with the threaded heat sink
bore enables the cylindrical container to be unscrewed from the
threaded heat sink bore to replace a cylindrical container having a
defective semiconductor component. Preferably, a recess is defined
in an exterior surface of the first end wall for matingly receiving
a tool for rotating the cylindrical container relative to the
threaded heat sink bore of the heat sink.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Other objects, features and advantages of the present
invention will become apparent from the detailed description of the
invention which follows, when considered in light of the
accompanying drawings in which:
[0023] FIG. 1 is an isometric view of an alternator containing a
rectifier circuit of the prior art.
[0024] FIG. 2 is an enlarged view of the rectifier circuit of FIG.
1.
[0025] FIG. 3 is an exploded view of the rectifier circuit of FIG.
2.
[0026] FIG. 4 is an isometric view of a thermal transfer container
of the prior art for transferring heat from a semiconductor diode
to a heat sink.
[0027] FIG. 5 is a bottom view of the thermal transfer container of
FIG. 4.
[0028] FIG. 6 is a side view of FIG. 5.
[0029] FIG. 7 is a view of the thermal transfer container of FIGS.
4-6 secured to a heat sink.
[0030] FIG. 8 is an enlarged view along line 8-8 in FIG. 7.
[0031] FIG. 9 is a magnified view of FIG. 8.
[0032] FIG. 10 is an isometric view of an alternator containing a
rectifier circuit of the present invention.
[0033] FIG. 11 is an enlarged view of the rectifier circuit of FIG.
10.
[0034] FIG. 12 is a partially exploded view of the rectifier
circuit of FIG. 11.
[0035] FIG. 13 is a fully exploded view of the rectifier circuit of
FIG. 11.
[0036] FIG. 14 is an isometric view of a thermal transfer container
of the present invention for transferring heat from a semiconductor
diode to a heat sink.
[0037] FIG. 15 is a bottom view of the thermal transfer container
of FIG. 14.
[0038] FIG. 16 is a side view of FIG. 15.
[0039] FIG. 17 is a top view of FIG. 15.
[0040] FIG. 18 is a sectional view along line 18-18 in FIG. 15.
[0041] FIG. 19 is a view of the thermal transfer container of FIGS.
14-18 secured to a first type of heat sink.
[0042] FIG. 20 is an enlarged view along line 20-20 in FIG. 19.
[0043] FIG. 21 is a view of the thermal transfer container of FIGS.
14-18 secured to a second type of heat sink.
[0044] FIG. 22 is an enlarged view along line 22-22 in FIG. 21.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout, and prime notation is used to indicate similar
elements in alternative embodiments.
[0046] FIG. 1 is an isometric view of an alternator 10 of the prior
art shown as a typical alternator for use with an engine of an
automobile, boat, airplane or the like. The alternator 10 comprises
a housing 20 extending from a drive end frame 21 to a slip ring end
frame 22. The housing 20 comprises a substantially cylindrical
outer surface 23 defining an alternator interior space 24. A stator
30 has a stator winding 32 mounted to the housing 20 within the
interior space 24 thereof. Typically, the stator winding 32
comprises a plurality of stator windings wound about a stator
lamination in a three-phase configuration.
[0047] A rotor 34 having a rotor winding 36 is rotatably mounted
within the stator 30. The rotor 34 is mounted to a drive shaft 40
having a first and a second end 41 and 42. A first and a second
bearing 44 and 46 are secured to the drive end frame 21 and the
slip ring end frame 22 for journaling the drive shaft 40.
[0048] The first end 41 of the drive shaft 40 is rotated by an
engine (not shown) or the like for generating electrical power. The
rotation of the rotor winding 36 of the rotor 34 within the stator
winding 32 of the stator 30 generates alternating current (AC)
electrical power. A rectifier assembly 50 is provided for
converting the alternating current (AC) electrical power into
direct current (DC) electrical power.
[0049] FIG. 2 is an enlarged view of the prior art rectifier
assembly 50 of FIG. 1. In this example, the rectifier assembly 50
is shown as a full wave rectifier bridge comprising a plurality of
negative diodes 51 and a plurality of positive diodes 52. Each of
the plurality of negative diodes 51 is mounted within a negative
thermal transfer container 55. Similarly, each of the plurality of
positive diodes 52 is mounted within a positive thermal transfer
container 56.
[0050] The plurality of negative thermal transfer containers 55
containing the negative diodes 51 are mounted to a negative heat
sink 60. Similarly, the plurality of positive thermal transfer
containers 55 containing the positive diodes 52 are mounted to a
positive heat sink 70. The negative heat sink 60 and the positive
heat sink 70 are secured relative to one another with an insulator
90 interposed therebetween. An external terminal 100 provides a
connection strip for the negative diodes 51 and the positive diodes
52.
[0051] FIG. 3 is an enlarged exploded view of the prior art
rectifier assembly 50 of FIG. 2. The negative heat sink 60 is shown
having a generally flat configuration having a first and a second
side 61 and 62 and a peripheral edge 63. The negative heat sink 60
defines a plurality of negative diode bores 64-66 extending through
the negative heat sink 60. A plurality of mounting holes 67-69
extend through the first and second sides 61 and 62 for mounting
the negative heat sink 60.
[0052] Each of the plurality of negative diode bores 64-66 is
adapted to receive a negative thermal transfer container 55 housing
the negative diode 51. As will be described in greater detail
hereinafter, each of the plurality of negative diode bores 64-66
receives a negative thermal transfer container 55 in a press fit
engagement.
[0053] The positive heat sink 70 is shown having a generally flat
configuration having a first and a second side 71 and 72 and a
peripheral edge 73. The positive heat sink 70 defines a plurality
of positive diode bores 74-76 extending through the positive heat
sink 70. A plurality of mounting holes 77-79 extend through the
first and second sides 71 and 72 for mounting the positive heat
sink 70. In this example, the plurality of mounting holes 77-79 of
the positive heat sink 70 are aligned with the plurality of
mounting holes 67-69 of the negative heat sink 60.
[0054] Each of the plurality of positive diode bores 74-76 is
adapted to receive a positive thermal transfer container 56 housing
a positive diode 52. As will be described in greater detail
hereinafter, each of the plurality of positive diode bores 74-76
receives a positive thermal transfer container 56 in a press fit
engagement.
[0055] The positive heat sink 70 includes a supplemental heat sink
80 secured to the second side 72 of the positive heat sink 70. The
supplemental heat sink 80 adds additional mass and additional
surface area to the positive heat sink 70 for cooling the plurality
of positive diodes 52 housed within the plurality of positive
thermal transfer containers 56.
[0056] In this example, the a peripheral edge 73 of the positive
heat sink 70 is provided with notches 84-86 for accommodating for
the negative thermal transfer containers 55 located in the negative
diode bores 64-66 of the negative heat sink 60.
[0057] The insulator 90 defines a peripheral edge 93 having notches
94-96. The notches 94-96 are provided for accommodating for the
negative thermal transfer containers 55 located in the negative
diode bores 64-66 of the negative heat sink 60. A plurality of
mounting holes 97-99 extending through the insulator 90 for
mounting between the negative heat sink 60 and the positive heat
sink 70.
[0058] The external terminal 100 includes contacts 101, 103 and 105
for connecting to the negative diodes 51 and contacts 102, 104 and
106 for connecting to the positive diodes 52. Plural mounting holes
107 and 108 are aligned with the plural mounting holes 67 and 68 of
the negative heat sink 60. The contacts 101-106 are connected to
external contacts 111-114.
[0059] The rectifier assembly 50 comprises a stacked assembly of
the negative heat sink 60, the insulator 90, the positive heat sink
70 and the external terminal 100. The plurality of negative thermal
transfer containers 55 are press fit into the plurality of negative
diode bores 64-66. The plurality of positive thermal transfer
containers 56 are press fit into the plurality of positive diode
bores 74-76. The insulator 90 is located between the negative heat
sink 60 and the positive heat sink 70. The connector 100 is
positioned adjacent the second side 72 of the positive heat sink 70
as shown in FIG. 3. The stacked assembly is secured with a
mechanical fastener extending through the mounting holes in the
negative heat sink 60, the insulator 90, the positive heat sink 70
and the external terminal 100.
[0060] FIGS. 4-9 illustrate various views of thermal transfer
container 56 of the prior art for containing the positive diode 52.
Although the thermal transfer container 56 is shown associated with
the positive diode 52, it should be understood that the thermal
transfer container 55 for the negative diode 51 functions in a
similar manner.
[0061] The thermal transfer container 56 is a generally cylindrical
container 120 extending between a first and a second cylindrical
end 121 and 122. The generally cylindrical container defines an
inner cylindrical surface 123 and an outer cylindrical surface 124.
The thermal transfer container is formed of a metallic material
such as aluminum.
[0062] A first end wall 130 closes the first end of the cylindrical
container. The first end wall 130 defines an inner end wall surface
131 and an outer end wall surface 132. The first end wall 130 is
integrally formed with the first end 121 of the cylindrical
container 120 as a one piece unit. The second end 122 of the
cylindrical container 120 defines an opening 140. The generally
cylindrical container 120 in combination with the first end wall
130 defines a cup shape having an inner volume 142 for containing
the positive diode 52.
[0063] The positive diode 52 comprises a wafer 150 having a first
and a second terminal 151 and 152. The first terminal 151 is shown
as the negative terminal of the semiconductor diode whereas the
second terminal 152 is shown as the positive terminal of the
positive diode 52. The semiconductor diode is a glass passivated
silicon diode.
[0064] A first connector 161 connects the first terminal 151 of the
positive diode 52 to the inner end wall 131 surface of the first
end wall 130 of the cylindrical container 120. The first connector
161 directly connects the positive diode 52 to the first end wall
130 of the cylindrical container 120. Typically, the first
connector 161 comprises a first solder connector to provide a
simultaneous electrical and thermal connection of the positive
diode 52 to the cylindrical container 120.
[0065] A second connector 162 comprises an electrical lead 170
extending between a first and a second electrical lead end 171 and
172. The second connector 162 directly electrically affixes the
first end 171 of the electrical lead 170 to the second terminal 152
of the positive diode 52. The second end 172 of the electrical lead
170 extends from the opening 140 in the second end 122 of the
cylindrical container 120. Typically, the second connector 162
comprises a second solder connector to provide an electrical
connection of the first end 171 of the electrical lead 170 to the
positive diode 52.
[0066] The curable material 180 fills the inner volume 140 of the
thermal transfer container 56 for retaining the positive diode 52
within the thermal transfer container 56. The curable material 180
is an insulating curable material 180 such as a curable epoxy
material or any suitable curable material. The curable material 180
adds mechanical strength to the electrical lead 170 extending from
the opening 140 in the second end 122 of the cylindrical container
120.
[0067] As best shown in FIG. 9, a knurl 190 extends about the outer
cylindrical surface 124 of the cylindrical container 120. The knurl
190 includes a series of knurl projections 192 spaced about the
outer cylindrical surface 124 of the cylindrical container 120. The
series of voids 194 are defined between each adjacent pair of the
knurl projections 192.
[0068] Each of the series of knurl projections 192 is deformable
for enabling the outer cylindrical surface 124 of the cylindrical
container 120 to be press fit into the positive diode bore 75. The
cylindrical container 120 is formed from a conductive deformable
material such as aluminum for enabling the series of knurl
projections 192 to be deformed to electrically and thermally
connect the cylindrical container 120 to the positive heat sink
70.
[0069] The thermal transfer container 56 of the prior art provided
reasonable reliable electrical and thermal connection of the
cylindrical container 120 to the positive heat sink 70. However,
the thermal transfer container 56 of the prior art suffered from
several inherent problems.
[0070] Variation in the outer diameter of the knurl projections 192
and/or variation in the inner diameter of the positive diode bore
75 produced unreliable electrical and thermal connection of the
cylindrical container 120 with the positive heat sink 70.
[0071] When the variation in the knurl projections 192 and/or the
positive diode bore 75 were within tolerance, only the peaks of the
knurl projections 192 made electrical and thermal contact with the
positive heat sink 70. The surface area represented by the series
of voids 194 did not make electrical and thermal contact with the
positive heat sink 70. This lack of electrical and thermal contact
increased the electrical resistance and decreased the thermal
conductivity to the positive heat sink 70.
[0072] When the variation in the knurl projections 192 and/or the
positive diode bore 75 had a loose tolerance, many of the peaks of
the knurl projections 192 did not make electrical and thermal
contact with the positive heat sink 70. This lack of electrical and
thermal contact increased the electrical resistance and decreased
the thermal conductivity to the positive heat sink 70.
[0073] When the variation in the knurl projections 192 and/or the
positive diode bore 75 had a tight tolerance, the process of press
fitting the thermal transfer container 56 into the positive diode
bore 75 deformed the cylindrical container 120. In some cases, the
deformation of the cylindrical container 120 damaged the positive
diode 52 within the cylindrical container 120. When the thermal
transfer container 56 was pressed into the positive heat sink 70, a
thermal transfer container 56 with a damaged the positive diode 52
could not be removed easily from the positive heat sink 70.
Accordingly, the entire rectifier assembly 50 had to be scrapped
during the manufacturing process.
[0074] When a positive diode 52 failed during operation, the press
fit engagement prevent easy replacement of the failed positive
diode 52 without the replacement of the entire rectifier assembly
50.
[0075] FIG. 10 is an isometric view of an alternator 210 of an
alternator incorporating the present invention. The alternator 210
comprises a housing 220 extending from a drive end frame 221 to a
slip ring end frame 222. The housing 220 comprises a substantially
cylindrical outer surface 223 defining an alternator interior space
224. A stator 230 has a stator winding 232 mounted to the housing
220 within the interior space 24.
[0076] A rotor 234 having a rotor winding 236 is rotatably mounted
within the stator 230. The rotor 234 is mounted to a drive shaft
240 having a first and a second end 241 and 242 supported by a
first and a second bearing 44 and 46.
[0077] The alternator 210 of the present invention incorporates an
improved rectifier assembly 250 for converting the alternating
current (AC) electrical power into direct current (DC) electrical
power in a more efficient and reliable manner.
[0078] FIG. 11 is an enlarged view of the improved rectifier
assembly 250 of FIG. 10 comprising a plurality of negative diodes
251 and a plurality of positive diodes 252. Each of the plurality
of negative diodes 251 is mounted within a negative thermal
transfer container 255. Similarly, each of the plurality of
positive diodes 252 is mounted within a positive thermal transfer
container 256.
[0079] The plurality of negative thermal transfer containers 255
containing the negative diodes 251 are mounted to a negative heat
sink 260. The plurality of positive thermal transfer containers 256
containing the positive diodes 252 are mounted to a positive heat
sink 270. The negative heat sink 260 and the positive heat sink 270
are secured relative to one another with an insulator 290
interposed therebetween. An external terminal 300 provides a
connection strip for the negative diodes 251 and the positive
diodes 252.
[0080] FIG. 12 is an exploded view of the improved rectifier
assembly 250 of FIG. 11. The negative heat sink 260 has a first and
a second side 261 and 262 and a peripheral edge 263. The negative
heat sink 260 defines a plurality of negative diode bores 264-266
and a plurality of mounting holes 267-269 for mounting the negative
heat sink 260. Each of the plurality of negative diode bores
264-266 is adapted to receive a negative thermal transfer container
255 housing the negative diode 251.
[0081] The positive heat sink 270 has a first and a second side 271
and 272 and a peripheral edge 273. The positive heat sink 270
defines a plurality of positive diode bores 274-276 and a plurality
of mounting holes 277-279. The plurality of mounting holes 277-279
of the positive heat sink 270 are aligned with the plurality of
mounting holes 267-269 of the negative heat sink 260. Each of the
plurality of positive diode bores 274-276 is adapted to receive a
positive thermal transfer container 256 housing a positive diode
252.
[0082] The positive heat sink 270 includes a supplemental heat sink
280 secured to the second side 272 of the positive heat sink 270
for providing additional cooling for the plurality of positive
diodes 252 housed within the plurality of positive thermal transfer
containers 256.
[0083] The peripheral edge 273 of the positive heat sink 270 is
provided with notches 284-286 for accommodating for the negative
thermal transfer containers 255 of the negative heat sink 260.
[0084] The insulator 290 defines a peripheral edge 293 having
notches 294-296. The notches 294-296 are provided for accommodating
for the negative thermal transfer containers 255 of the negative
heat sink 260. A plurality of mounting holes 297-299 extending
through the insulator 290 for mounting between the negative heat
sink 260 and the positive heat sink 270.
[0085] The external terminal 300 includes contacts 301, 303 and 305
for connecting to the negative diodes 251 and contacts 302, 304 and
306 for connecting to the positive diodes 252. Plural mounting
holes 307 and 308 are aligned with the plural mounting holes 267
and 268 of the negative heat sink 260. The contacts 301-306 are
connected to external contacts 311-314.
[0086] The rectifier assembly 250 comprises a stacked assembly of
the negative heat sink 260, the insulator 290, the positive heat
sink 270 and the external terminal 300. The stacked assembly is
secured with a mechanical fastener extending through the mounting
holes in the negative heat sink 260, the insulator 290, the
positive heat sink 270 and the external terminal 300.
[0087] FIG. 13 is an exploded view of the improved rectifier
assembly 250 of FIG. 12. Each of the plurality of negative thermal
transfer containers 255 includes external threads 255T. Similarly,
each of the plurality of negative diode bores 264-266 of the
negative heat sink 260 is shown as a threaded bore having threads
264T-266T. In contrast to the prior art shown in FIGS. 1-11, each
of the plurality of negative diode bores 264-266 is adapted to
receive a negative thermal transfer container 255 housing the
negative diode 251 in a threaded engagement.
[0088] Each of the plurality of positive thermal transfer
containers 256 includes external threads 265T. Similarly, each of
the plurality of positive diode bores 274-276 of the positive heat
sink 270 is shown as a threaded bore having threads 274T-276T. In
contrast to the prior art shown in FIGS. 1-11, each of the
plurality of positive diode bores 274-276 is adapted to receive a
positive thermal transfer container 256 housing the positive diode
252 in a threaded engagement.
[0089] FIGS. 14-18 illustrate various views of thermal transfer
container 256 of the present invention for containing the positive
diode 252. The thermal transfer container 255 for the negative
diode 251 is identical to the thermal transfer container 256 for
containing the positive diode 252.
[0090] The thermal transfer container 256 is a generally
cylindrical container 320 extending between a first and a second
cylindrical end 321 and 322 defining an inner cylindrical surface
323 and an outer cylindrical surface 324. Preferably, the thermal
transfer container is formed of a metallic material such as
aluminum, copper or the like.
[0091] A first end wall 330 closes the first end 321 of the
cylindrical container 320. The first end wall 330 defines an inner
end wall surface 331 and an outer end wall surface 332. The first
end wall 330 is integrally formed with the first end 321 of the
cylindrical container 320 as a one piece unit. The second end 322
of the cylindrical container 320 defines an opening 340. The
generally cylindrical container 320 in combination with the first
end wall 330 defines a cup shape having an inner volume 342 for
containing the positive diode 252.
[0092] The positive diode 252 comprises a wafer 350 having a first
and a second terminal 351 and 352. The first terminal 351 is shown
as the negative terminal of the semiconductor diode whereas the
second terminal 352 is shown as the positive terminal of the
positive diode 252. The semiconductor diode is a glass passivated
silicon diode.
[0093] A first connector 361 connects the first terminal 351 of the
positive diode 252 to the inner end wall 331 surface of the first
end wall 330 of the cylindrical container 320. The first connector
361 directly connects the positive diode 252 to the first end wall
330 of the cylindrical container 320. Typically, the first
connector 361 comprises a first solder connector to provide a
simultaneous electrical and thermal connection of the positive
diode 252 to the cylindrical container 320.
[0094] A second connector 362 comprises an electrical lead 370
extending between a first and a second electrical lead end 371 and
372. The second connector 362 directly electrically affixes the
first end 371 of the electrical lead 370 to the second terminal 352
of the positive diode 252. The second end 272 of the electrical
lead 270 extends from the opening 340 in the second end 322 of the
cylindrical container 320. Typically, the second connector 362
comprises a second solder connector to provide an electrical
connection of the first end 371 of the electrical lead 370 to the
positive diode 252.
[0095] The curable material 380 such as a curable epoxy material or
any suitable curable material fills the inner volume 340 of the
thermal transfer container 256 for retaining the positive diode 252
within the thermal transfer container 256 and for adding mechanical
strength to the electrical lead 370.
[0096] As best shown in FIGS. 14, 16 and 17, the outer cylindrical
surface 324 of the cylindrical container 320 of the thermal
transfer container 256 defines the threads 256T. The threads 256T
define thread projections 392 separated by thread voids 394. The
threads 256T are integrally formed in the outer cylindrical surface
324 of the cylindrical container 320.
[0097] The first end wall 330 extends radially outward from the
outer cylindrical sidewall 324 of the cylindrical container 320 to
form a radial flange 400. The radial flange 400 extends beyond the
outer cylindrical sidewall 324 defining an axial planar surface 402
and a radial cylindrical surface 404 separated by a shoulder 406.
The radial flange 400 is integrally formed with the cylindrical
container 320 as a one piece unit.
[0098] As best shown in FIG. 18, the outer end wall surface 332 of
the first end wall 330 of the cylindrical container 320 includes a
recess 410 defined in the outer end wall surface 332. The recess
410 defined in the outer end wall surface 332 is adapted to
matingly receive a tool (not shown) for rotating the cylindrical
container 320 for threadably engaging and disengaging the thermal
transfer container 256 from the plurality of positive diode bores
274-276. In this example, the recess 410 is shown as a groove 411
and a cross-groove 412 for matingly receiving a tool such as a
Phillips head type screwdriver and the like. Although the recess
410 has been shown as a specific type having a groove 411 and a
cross-groove 412, it should be understood that the recess 410 may
take any suitable form for threadably engaging and disengaging the
thermal transfer container 256 from the plurality of positive diode
bores 274-276.
[0099] FIG. 19 is a view of the positive thermal transfer container
256 of FIGS. 14-18 secured to the positive heat sink 270. The
positive thermal transfer containers 256 are threadably engaged
with the positive diode bores 274-276 for providing electrical and
thermal connection between the positive thermal transfer containers
256 and the positive heat sink 270.
[0100] FIG. 20 is an enlarged view along line 19-19 in FIG. 19
illustrating the positive thermal transfer container 256 threadably
engaged with the positive diode bore 275.
[0101] The positive diode bore 275 includes the threads 275T formed
within the positive diode bore 275. The threads define 275T define
thread projections 422 separated by thread voids 424. The threads
275T are integrally formed in the positive heat sink 270.
[0102] The positive diode bore 275 includes a counterbore 430
located adjacent to the first side 271 of the positive heat sink
270. The counterbore 430 extends from the first side 271 of the
positive heat sink 270 to define an axial planar surface 432 and a
radial cylindrical surface 434 separated by a shoulder 436. The
counterbore 430 is integrally formed with the positive heat sink
270.
[0103] The positive thermal transfer container 256 is threadably
engaged with the positive diode bores 275 for providing electrical
and thermal connection between the positive thermal transfer
containers 256 and the positive heat sink 270. The thread
projections 392 and the thread voids 394 of the thermal transfer
container 256 cooperate with the thread voids 424 and the thread
projections 422 of the positive heat sink 270 for increasing the
area of contact between the positive thermal transfer container 256
and the positive heat sink 270. In addition, the axial planar
surface 402 of the positive thermal transfer container 256 engages
with the axial planar surface 432 of the counterbore 430 for
increasing the area of contact between the positive thermal
transfer container 256 and the positive heat sink 270. The increaed
area of contact between the positive thermal transfer container 256
and the positive heat sink 270 provides an enhanced electrical and
thermal conduction between the positive thermal transfer container
256 and the positive heat sink 270.
[0104] FIG. 21 is a view of the negative thermal transfer container
255 of FIGS. 12 and-13 secured to the negative heat sink 260. The
negative thermal transfer containers 255 are threadably engaged
with the negative diode bores 264-266 for providing electrical and
thermal connection between the negative thermal transfer containers
255 and the negative heat sink 260. The negative thermal transfer
containers 255 are identical to the positive thermal container
shown in FIGS. 14-20 and incorporates similar reference numerals
for similar parts.
[0105] FIG. 22 is an enlarged view along line 22-22 in FIG. 21
illustrating the negative thermal transfer container 255 threadably
engaged with the negative diode bore 265. The negative diode bore
265 includes the threads 265T formed within the negative diode bore
265. The threads define 265T define thread projections 442
separated by thread voids 444. The threads 265T are integrally
formed in the negative heat sink 260.
[0106] The negative diode bore 265 includes a counterbore 450
located adjacent to the first side 261 of the negative heat sink
260. The counterbore 450 extends from the first side 261 of the
negative heat sink 260 to define an axial planar surface 452 and a
radial cylindrical surface 454 separated by a shoulder 456. The
counterbore 450 is integrally formed with the negative heat sink
260.
[0107] The negative thermal transfer container 255 is threadably
engaged with the negative diode bores 265 for providing electrical
and thermal connection between the negative thermal transfer
containers 255 and the negative heat sink 260. The thread
projections 392 and the thread voids 394 of the negative thermal
transfer container 255 cooperate with the thread voids 444 and the
thread projections 442 of the negative heat sink 260 for increasing
the area of contact between the negative thermal transfer container
255 and the negative heat sink 260. In addition, the axial planar
surface 402 of the negative thermal transfer container 255 engages
with the axial planar surface 452 of the counterbore 450 for
increasing the area of contact between the negative thermal
transfer container 255 and the negative heat sink 260. The
increased area of contact between the negative thermal transfer
container 255 and the negative heat sink 260 provides an enhanced
electrical and thermal conduction between the negative thermal
transfer container 255 and the negative heat sink 260. A heat rise
test comparison between the diode rectifier of the present
invention and press fit diode rectifier is shown in Table 1
below.
1TABLE 1 HEAT RISE TEST SCREW DIODE PRESS FIT DIODE RECTIFIER
RECTIFIER DR4000 (ND) Transpo DR4000 Temperature (deg C.)
Temperature (deg C.) Positive POS Negative NEG HS Positive POS
Negative NEG Time HS HS HS Wire Output HS HS HS HS Output (mins)
diode Wire #2 diode #2 Current diode Wire #2 diode Wire #2 Current
0 26.0 26.0 25.6 23.5 97 24.0 24.0 24.0 24.0 97 1 91.0 81.0 67.8
44.9 84.0 73.0 73.0 67.0 2 105.0 98.0 73.2 52.1 107.0 98.0 72.0
81.0 3 111.0 105.0 74.7 70.0 115.0 108.0 80.8 83.4 4 114.0 108.0
75.6 75.1 119.0 111.0 87.1 92.6 5 115.0 109.0 74.7 77.9 97 121.0
113.0 90.3 95.3 97 6 116.0 110.0 76.3 79.3 122.0 114.0 92.6 95.7 7
116.0 111.0 76.0 80.2 122.0 115.0 93.7 97.4 8 117.0 112.0 76.2 80.4
122.0 115.0 95.0 98.5 9 117.0 112.0 76.4 80.4 122.0 116.0 95.5 98.8
10 117.0 112.0 76.9 80.2 93 122.0 116.0 96.0 99.1 94 11 117.0 112.0
77.0 80.1 123.0 116.0 96.3 99.3 12 117.0 112.0 77.1 79.9 123.0
116.0 96.5 99.4 13 117.0 112.0 77.2 79.6 123.0 116.0 96.8 99.6 14
117.0 112.0 77.4 79.4 123.0 116.0 97.0 99.8 15 117.0 113.0 77.8
79.1 92 123.0 116.0 97.0 99.8 92 16 117.0 113.0 77.1 78.8 123.0
117.0 97.3 99.9 17 117.0 113.0 77.8 78.7 123.0 117.0 97.3 100.0 18
117.0 112.0 77.6 78.6 123.0 117.0 97.5 100.1 19 117.0 113.0 77.9
78.3 123.0 117.0 97.6 100.1 20 118.0 113.0 78.0 78.1 91 123.0 117.0
97.6 100.2 91 21 117.0 113.0 77.9 77.9 122.0 117.0 97.8 100.2 22
118.0 114.0 78.2 77.6 122.0 117.0 97.9 100.4 23 118.0 114.0 78.0
77.4 123.0 118.0 98.0 100.4 24 118.0 113.0 77.9 77.2 123.0 118.0
98.2 100.4 25 118.0 114.0 78.5 77.1 91 123.0 118.0 98.3 100.6 91 26
118.0 113.0 78.5 76.9 123.0 118.0 98.4 100.7 27 118.0 114.0 78.2
76.6 123.0 118.0 98.3 100.7 28 118.0 114.0 78.7 76.5 123.0 118.0
98.4 100.7 29 119.0 114.0 78.5 76.4 123.0 118.0 98.5 100.9 30 119.0
114.0 79.0 76.3 91 123.0 119.0 98.9 101.0 91 Date of Test 37715.0
Room Temp 23.1 deg C. Date of Test 37715.0 Room Temp 23.2 deg C.
POS HS Wire #1 and POS HS Wire #2 used Fluke 77 DMM ID no. 4736 and
Thermocouple Module ID no. 5478 NEG HS Wire #1 and NEG HS Wire #2
used Fluke 87III DMM ID no. 3849 and Thermocouple Module ID no. 547
Alternator Output 160A Alternator Speed 3000 rpm
[0108] The thermal transfer container of the present invention
provides a solution for many of the disadvantages of the prior
art.
[0109] The threaded engagement between the thermal transfer
container and the heat sink reduces the unreliable electrical and
thermal connection produced by the variation in the outer diameter
of the knurl projections and/or variation in the inner diameter of
the diode bore of the prior art. The thread projections and the
thread voids of the thermal transfer container cooperate with the
thread voids and the thread projections of the heat sink for
increasing the area of contact between the thermal transfer
container and the heat sink, compensating for variation in the
thread projections and/or thread voids in the thermal transfer
container and/or heat sink.
[0110] The threaded engagement between the thread projections and
the thread voids of the thermal transfer container with the thread
voids and the thread projections of the heat sink of the present
invention provides an enhanced electrical and thermal conductivity
between the thermal transfer container and a heat sink relative to
the prior art.
[0111] The engagement between the axial planar surface of the
thermal transfer container engages with the axial planar surface of
the counterbore enhancing the electrical and thermal conduction
between the thermal transfer container and the heat sink.
[0112] The thermal transfer container is not deformed when the
thermal transfer container is threadably engaged with the heat sink
thus eliminating any possibility of damaging the diode within the
cylindrical container.
[0113] The threaded engagement between the thermal transfer
container and the heat sink enables the diode to be replaced in the
event of failure during operation without the replacement of the
entire rectifier assembly.
[0114] The present invention has been described with reference to
use within a rectifier assembly for an alternator. It should be
understood that the present disclosure is by way of example, and
that the present invention may be incorporates into any application
requiring the enhanced electrical and/or thermal transfer of heat
to a heat sink.
[0115] Although the invention has been described in its preferred
form with a certain degree of particularity, it is understood that
the present disclosure of the preferred form has been made only by
way of example and that numerous changes in the details of
construction and the combination and arrangement of parts may be
resorted to without departing from the spirit and scope of the
invention.
[0116] Many modifications and other embodiments of the invention
will come to the mind of one skilled in the art having the benefit
of the teachings presented in the foregoing descriptions and the
associated drawings. Therefore, it is understood that the invention
is not to be limited to the specific embodiments disclosed, and
that modifications and embodiments are intended to be included
within the scope of the appended claims.
* * * * *