U.S. patent application number 13/862473 was filed with the patent office on 2014-10-16 for fluid cooled semiconductor die package.
The applicant listed for this patent is Chee Seng Foong, Tim V. Pham. Invention is credited to Chee Seng Foong, Tim V. Pham.
Application Number | 20140306336 13/862473 |
Document ID | / |
Family ID | 51661092 |
Filed Date | 2014-10-16 |
United States Patent
Application |
20140306336 |
Kind Code |
A1 |
Foong; Chee Seng ; et
al. |
October 16, 2014 |
FLUID COOLED SEMICONDUCTOR DIE PACKAGE
Abstract
A fluid cooled semiconductor die package includes a package
support substrate with a die mounting surface and an opposite
package mounting surface. The package support substrate has
external connector solder deposits on respective external connector
pads of the package mounting surface, and a package fluid inlet
duct and a package fluid outlet duct each providing fluid
communication between the die mounting surface and package mounting
surface. A semiconductor die is mounted on the die mounting
surface. The die has external terminals electrically connected to
the external connector pads. An inlet solder deposit is soldered to
an inlet pad of the package mounting surface. The inlet pad
surrounds an entrance of the fluid inlet duct. An outlet solder
deposit is soldered to an outlet pad of the package mounting
surface. The outlet pad surrounds an exit of the package fluid
inlet duct.
Inventors: |
Foong; Chee Seng; (Sg Buloh,
MY) ; Pham; Tim V.; (Austin, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Foong; Chee Seng
Pham; Tim V. |
Sg Buloh
Austin |
TX |
MY
US |
|
|
Family ID: |
51661092 |
Appl. No.: |
13/862473 |
Filed: |
April 15, 2013 |
Current U.S.
Class: |
257/714 ;
438/122 |
Current CPC
Class: |
H01L 2224/73204
20130101; H01L 2924/16251 20130101; H01L 2225/1094 20130101; H01L
24/32 20130101; H01L 24/16 20130101; H01L 2224/16225 20130101; H01L
25/105 20130101; H01L 2225/1023 20130101; H01L 23/49827 20130101;
H01L 2924/15311 20130101; H01L 2224/32225 20130101; H01L 2924/167
20130101; H01L 2225/107 20130101; H01L 2924/163 20130101; H01L
23/473 20130101; H01L 2924/16152 20130101; H01L 2224/32225
20130101; H01L 2224/16225 20130101; H01L 2924/00012 20130101; H01L
2924/00 20130101; H01L 2224/32225 20130101; H01L 2224/73204
20130101; H01L 2224/16225 20130101; H01L 21/50 20130101; H01L
2924/15311 20130101; H01L 24/73 20130101; H01L 2924/1533 20130101;
H01L 23/3675 20130101; H01L 2224/73253 20130101; H01L 2224/73204
20130101 |
Class at
Publication: |
257/714 ;
438/122 |
International
Class: |
H01L 23/473 20060101
H01L023/473; H01L 21/50 20060101 H01L021/50 |
Claims
1. A fluid cooled semiconductor die package, comprising: a package
support substrate with a die mounting surface and an opposite
package mounting surface, the package support substrate having
external connector solder deposits on respective external connector
pads of the package mounting surface, wherein the package support
substrate has at least one package fluid inlet duct and at least
one package fluid outlet duct each providing fluid communication
between the die mounting surface and the package mounting surface;
a semiconductor die mounted on the die mounting surface of the
package support substrate, the semiconductor die having external
terminals selectively electrically connected to the external
connector pads; an inlet solder deposit soldered to an inlet pad of
the package mounting surface, wherein the inlet pad surrounds an
entrance of the package fluid inlet duct; and an outlet solder
deposit soldered to an outlet pad of the package mounting surface,
wherein the outlet pad surrounds an exit of the package fluid inlet
duct, wherein each of the external connector solder deposits is
formed from a single solder ball, and the inlet solder deposit is
formed from at least one solder ball that is the same size as the
single solder ball.
2. The fluid cooled semiconductor die package of claim 1, further
comprising a lid mounted to the die mounting surface, wherein the
lid has at least one heat transfer chamber therein that is
hermetically coupled to the package fluid inlet duct and the
package fluid outlet duct.
3. The fluid cooled semiconductor die package of claim 2, wherein
the heat transfer chamber is formed from a surface of the
semiconductor die and a wall of the lid.
4. The fluid cooled semiconductor die package of claim 2, wherein
the lid has at least one lid inlet passage in fluid communication,
through the heat transfer chamber, with at least one lid outlet
passage, the lid inlet passage having a passage entrance
hermetically coupled to the package fluid inlet duct and the lid
outlet passage having a passage exit hermetically coupled to the
package fluid outlet duct.
5. The fluid cooled semiconductor die package of claim 3, wherein a
wall of the heat transfer chamber abuts a surface of the
semiconductor die.
6. The fluid cooled semiconductor die package of claim 1, wherein
the inlet pad is a metal-based annulus.
7. The fluid cooled semiconductor die package of claim 6, further
including an annular inlet pad in the die mounting surface.
8. The fluid cooled semiconductor die package of claim 7, further
including a metal based deposit on an inner surface of the package
fluid inlet duct, the metal based deposit forming a tube coupling
the inlet pad of the package mounting surface to the annular inlet
pad.
9. The fluid cooled semiconductor die package of claim 6, wherein
the inlet solder deposit is a solder globule that covers the
entrance to the package fluid inlet duct.
10. The fluid cooled semiconductor die package of claim 1, wherein
the external connector solder deposits form a ball grid array
external connector arrangement.
11. A fluid cooled circuit board system, comprising: a circuit
board with mounting pads thereon, the circuit board having a board
inlet duct and a board outlet duct; a package support substrate
with a die mounting surface and an opposite package mounting
surface, the package support substrate having external connector
solder deposits coupling between respective external connector pads
of the package mounting surface and the mounting pads of the
circuit board, wherein the package support substrate has at least
one package fluid inlet duct and at least one package fluid outlet
duct each providing fluid communication between the die mounting
surface and package mounting surface; a semiconductor die mounted
on the die mounting surface of the package support substrate, the
semiconductor die having external terminals selectively
electrically connected to the external connector pads; an inlet
solder deposit coupling an inlet pad of the package mounting
surface to an inlet pad of the circuit board, wherein the inlet pad
of the package mounting surface surrounds an entrance of the
package fluid inlet duct and the inlet pad of the circuit board
surrounds an exit of the board inlet duct, and the inlet solder
deposit has an inlet deposit aperture therein that provides a
hermetic coupling between the board inlet duct and package fluid
inlet duct; and an outlet solder deposit coupling an outlet pad of
the package mounting surface to an outlet pad of the circuit board,
wherein the outlet pad of the package mounting surface surrounds an
exit of the package fluid outlet duct and an outlet pad of the
circuit board surrounds an entrance of the board outlet duct, and
the outlet solder deposit has an outlet deposit aperture therein
that provides a hermetic coupling between the board outlet duct and
package fluid outlet duct, wherein the circuit board is mounted on
an additional substrate with an additional semiconductor die
mounted thereon, the additional substrate being mounted on an
additional circuit board that has an additional board inlet fluid
duct and an additional board fluid outlet duct, the additional
substrate having at least one intermediate inlet fluid duct with an
associated solder deposit with an aperture therein that provides a
hermetic coupling between the intermediate inlet fluid duct and the
additional board inlet fluid duct.
12. The fluid cooled circuit board system of claim 11, further
comprising is a lid mounted to the die mounting surface, the lid
having at least one heat transfer chamber therein that is
hermetically coupled to the package fluid inlet duct and package
fluid outlet duct.
13. The fluid cooled circuit board system of claim 12, wherein the
lid has at least one lid inlet passage in fluid communication,
through the heat transfer chamber, with at least one lid outlet
passage, the lid inlet passage having an passage entrance
hermetically coupled to the package fluid inlet duct and the lid
outlet passage having an passage exit hermetically coupled to the
package fluid outlet duct.
14. (canceled)
15. The fluid cooled circuit board system of claim 11, further
comprising a coupling solder deposit with a coupling aperture
therein that provides a hermetic coupling between the intermediate
inlet fluid duct and the board inlet duct of the circuit board.
16. A method for assembling a fluid cooled semiconductor die
package, the method including: providing a package support
substrate with a die mounting surface with external connector pads
and an opposite package mounting surface, the package support
substrate having at least one package fluid inlet duct and at least
one package fluid outlet duct each providing fluid communication
between the die mounting surface and package mounting surface;
mounting a semiconductor die on the die mounting surface, the
semiconductor die having external terminals that are selectively
electrically connected to the external connector pads; and
soldering external connector solder deposits to the external
connector pads, an inlet solder deposit to an inlet pad that
surrounds an entrance of the package fluid inlet duct, and an
outlet solder deposit to an outlet pad that surrounds an exit of
the package fluid inlet duct, wherein each of the external
connector solder deposits is formed from a single solder ball, and
the inlet solder deposit is formed from at least one solder ball
that is the same size as the single solder ball.
17. The method of claim 16, further including mounting a lid to the
die mounting surface, the lid having at least one heat transfer
chamber therein that is hermetically coupled to the package fluid
inlet duct and the package fluid outlet duct.
18. The method of claim 16, wherein the inlet solder deposit is a
solder globule that covers the entrance to the package fluid inlet
duct.
19. The method of claim 16, wherein the external connector solder
deposits form a ball grid array external connector arrangement.
20. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to integrated circuit
packaging and, more particularly, to a fluid cooled semiconductor
die package.
[0002] Electronic devices, such as integrated circuits or
semiconductor die packages, generate heat during operation. Such
packages are commonly cooled to ensure proper functioning and to
enable higher operating speeds. A basic package cooling system may
promote convective cooling using a fan that directs forced air to
flow over the package's outer surface. In addition, a heat sink
(e.g., a metal body having a substantially flat contact surface and
a plurality of projections or fins) may be placed in thermal
contact with the package. During operation, heat is conducted away
from the package and into the projections, which are convectively
cooled.
[0003] Although fairly reliable and inexpensive to implement,
convection cooling systems of the type described above are not
always adequate especially for packages that consume relatively
large currents. For this reason, refrigeration systems and piped
fluid coolant systems have been developed for cooling semiconductor
packages. These refrigeration systems and piped fluid coolant
systems often continually supply a refrigerant or liquid coolant
flow through the package by use of conduits, with the connections
between the conduits being hermetically sealed by small relatively
expensive hermetically sealable couplings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
preferred embodiments together with the accompanying drawings in
which:
[0005] FIG. 1 is a cross-sectional side view of a substrate and die
assembly, in accordance with a first preferred embodiment of the
present invention;
[0006] FIG. 2 is a top plan view of the substrate and die assembly
of FIG. 1;
[0007] FIG. 3 is a cross-sectional side view of an assembled fluid
cooled semiconductor die package, in accordance with a first
preferred embodiment of the present invention;
[0008] FIG. 4 is a cross-sectional side view of a fluid cooled
semiconductor die package, in accordance with the first preferred
embodiment of the present invention;
[0009] FIG. 5 is an underside plan view of the fluid cooled
semiconductor die package of FIG. 4;
[0010] FIG. 6 is a cross-sectional side view of a fluid cooled
circuit board system, in accordance with the first preferred
embodiment of the present invention;
[0011] FIG. 7 is a cross-sectional side view of a fluid cooled
semiconductor die package, in accordance with a second preferred
embodiment of the present invention;
[0012] FIG. 8 is a cross-sectional side view of a fluid cooled
circuit board system, in accordance with a third preferred
embodiment of the present invention;
[0013] FIG. 9 is a cross-sectional side view of a stacked fluid
cooled circuit board system, in accordance with a fourth preferred
embodiment of the present invention;
[0014] FIG. 10 is a cross-sectional side view of a stacked fluid
cooled circuit board system, in accordance with a fifth preferred
embodiment of the present invention;
[0015] FIG. 11 is a flow chart of a method for manufacturing a
fluid cooled semiconductor die package in accordance with a sixth
preferred embodiment of the present invention; and
[0016] FIG. 12 is a cross-sectional side view of an inlet solder
deposit on a package support substrate of the fluid cooled
semiconductor die package of FIG. 4.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] The detailed description set forth below in connection with
the appended drawings is intended as a description of presently
preferred embodiments of the invention, and is not intended to
represent the only forms in which the present invention may be
practised. It is to be understood that the same or equivalent
functions may be accomplished by different embodiments that are
intended to be encompassed within the spirit and scope of the
invention. In the drawings, like numerals are used to indicate like
elements throughout. Furthermore, terms "comprises," "comprising,"
or any other variation thereof, are intended to cover a
non-exclusive inclusion, such that module, circuit, device
components, structures and method steps that comprises a list of
elements or steps does not include only those elements but may
include other elements or steps not expressly listed or inherent to
such module, circuit, device components or steps. An element or
step proceeded by "comprises . . . a" does not, without more
constraints, preclude the existence of additional identical
elements or steps that comprises the element or step.
[0018] In one embodiment, the present invention provides for a
fluid cooled semiconductor die package comprising a package support
substrate with a die mounting surface and an opposite package
mounting surface. The package support substrate has external
connector solder deposits soldered to respective external connector
pads of the package mounting surface, and the package support
substrate has at least one package fluid inlet duct and at least
one package fluid outlet duct each providing fluid communication
between the die mounting surface and package mounting surface. A
semiconductor die is mounted on the die mounting surface of the
package support substrate, and the semiconductor die has external
terminals selectively electrically connected to the external
connector pads. There is an inlet solder deposit soldered to an
inlet pad of the package mounting surface, and the inlet pad
surrounds an entrance of the package fluid inlet duct. There is
also an outlet solder deposit soldered to an outlet pad of the
package mounting surface, and the outlet pad surrounds an exit of
the package fluid inlet duct.
[0019] In another embodiment, the present invention provides for a
fluid cooled circuit board system comprising a circuit board with
mounting pads thereon, the circuit board having a board inlet duct
and board outlet duct. There is a package support substrate with a
die mounting surface and an opposite package mounting surface, the
package support substrate has external connector solder deposits
coupling between respective external connector pads of the package
mounting surface and the mounting pads of the circuit board. The
package support substrate has at least one package fluid inlet duct
and at least one package fluid outlet duct each providing fluid
communication between the die mounting surface and package mounting
surface. A semiconductor die is mounted on the die mounting surface
of the package support substrate, and the semiconductor die has
external terminals selectively electrically connected to the
external connector pads. There is an inlet solder deposit coupling
an inlet pad of the package mounting surface to an inlet pad of the
circuit board. The inlet pad of the package mounting surface
surrounds an entrance of the package fluid inlet duct and the inlet
pad of the circuit board surrounds an exit of the board inlet duct.
The inlet solder deposit has an inlet deposit aperture therein that
provides a hermetic coupling between the board inlet duct and
package fluid inlet duct. There is an outlet solder deposit
coupling an outlet pad of the package mounting surface to an outlet
pad of the circuit board. The outlet pad of the package mounting
surface surrounds an exit of the package fluid outlet duct and an
outlet pad of the circuit board surrounds an entrance of the board
outlet duct. The outlet solder deposit has an outlet deposit
aperture therein that provides a hermetic coupling between the
board outlet duct and package fluid outlet duct.
[0020] In a further embodiment, the present invention provides for
a method of manufacturing a fluid cooled semiconductor die package,
the method includes providing a package support substrate with a
die mounting surface with external connector pads and an opposite
package mounting surface. The package support substrate has at
least one package fluid inlet duct and at least one package fluid
outlet duct each providing fluid communication between the die
mounting surface and package mounting surface. The method performs
a process of mounting a semiconductor die on the die mounting
surface, and the semiconductor die has external terminals that are
selectively electrically connected to the external connector pads.
The method further performs a process of soldering external
connector solder deposits to the external connector pads, an inlet
solder deposit to an inlet pad that surrounds an entrance of the
package fluid inlet duct, and an outlet solder deposit to an outlet
pad that surrounds an exit of the package fluid inlet duct.
[0021] Referring now to FIG. 1, a cross-sectional side view of a
substrate and die assembly 100 in accordance with a first preferred
embodiment of the present invention is shown. The substrate and die
assembly 100 has a package support substrate 105 with a die
mounting surface 110 and an opposite package mounting surface 115.
The package support substrate 105 has external connector pads 120
that are typically formed or deposited on or in the package
mounting surface 115. The package support substrate 105 also has at
least one package fluid inlet duct 130 and at least one package
fluid outlet duct 135 each providing fluid communication between
the die mounting surface 110 and package mounting surface 115. As
will be apparent to a person skilled in the art, these ducts 130
and 135 are formed by drilling apertures in the package support
substrate 105.
[0022] There is a semiconductor die 140 mounted (fixed) on the die
mounting surface 110 and the semiconductor die 140 has external
terminals 150 selectively electrically connected to the external
connector pads 120. Connection of the external terminals 150 to the
external connector pads 120 is by a conventional connector
arrangement 155 (shown in phantom) that can include: mounting pads
160 and conductive vias; or mounting pads 160, runners and
conductive vias. Such connector arrangements 155 are well known in
the art and are therefore not described in detail. Also, it will be
apparent that the semiconductor die 140 is mounted on the die
mounting surface 110 by soldered joints that electrically
interconnect aligned mounting pads 160 and external terminals 150
which are sealed by an epoxy resin 145 that also acts as a stress
buffer.
[0023] Referring to FIG. 2 there is illustrated a top plan view of
the substrate and die assembly 100. As shown in this embodiment,
there are three package fluid inlet ducts 130 and three package
fluid outlet ducts 135. However, other numbers and configurations
of ducts 130, 135 are possible as will be apparent to a person
skilled in the art.
[0024] Referring to FIG. 3 there is illustrated a cross-sectional
side view of an assembled fluid cooled semiconductor die package
300, in accordance with a first preferred embodiment of the present
invention. The assembled fluid cooled semiconductor die package 300
is the substrate and die assembly 100 with a heat transfer lid 305
mounted to the die mounting surface 110. The heat transfer lid 305
covers the semiconductor die 140 and in operation provides for
fluid cooling of the die 140. There are also solder balls 310 held
temporarily in place (by a flux paste) on respective external
connector pads 120 of the package mounting surface 115. The heat
transfer lid 305 has at least one lid inlet passage 315 in fluid
communication with at least one lid outlet passage 320. The heat
transfer lid 305 has a conduit that provides a heat transfer
chamber 325 that provides for the fluid communication between the
lid inlet passage 315 and the lid outlet passage 320. In this
embodiment, a wall 380 of the heat transfer chamber 325 abuts a
non-active surface 385 of the semiconductor die 140 thereby
facilitating the possibility of improved heat transfer between the
die 140 and chamber 325. To further improve heat transfer, a thin
layer of Thermal Interface Material (TIM) can be sandwiched between
the die 140 and wall 380.
[0025] A base 330 of the heat transfer lid 305 is fixed to the die
mounting surface 110 by an epoxy 335. The epoxy 335 provides a
hermetic seal and thus the lid inlet passage 315 is hermetically
coupled to the package fluid inlet duct 130 and the lid outlet
passage 135 is hermetically coupled to the package fluid outlet
duct 135. Consequently, the heat transfer chamber 325 is
hermetically coupled to the package fluid inlet duct 130 and
package fluid outlet duct 135.
[0026] There is an inlet pad 340 in the package mounting surface
115 that surrounds an entrance of the package fluid inlet duct 130.
A copper deposit, or any other metal-based deposit, forms the inlet
pad 340 in the package mounting surface 115. This inlet pad 340 is
an annulus and in this preferred embodiment there is also an
annular inlet pad 345, in the die mounting surface 110, which is
formed from a copper or other metal based deposit. Furthermore, an
inner surface of the fluid inlet duct 130 is coated with a copper
or other metal based deposit thereby forming a metallic inlet tube
350 coupling the inlet pad 340 to the annular inlet pad 345. A pair
of solder balls 355 is deposited on the inlet pad 340 and the
solder balls 355 are held temporarily in place by a flux paste. In
another embodiment a single solder ball may be used instead of the
pair of solder balls 355. In this regard, each of the solder balls
355, or the single solder ball, is the same size as the solder
balls 310.
[0027] There is also an outlet pad 360 in the package mounting
surface 115 that surrounds an exit of the package fluid outlet duct
135. A copper deposit, or any other metal-based deposit, forms the
outlet pad 360 in the package mounting surface 115. This outlet pad
360 is an annulus and in this preferred embodiment there is also an
annular outlet pad 365, in the die mounting surface 110, which is
formed from a copper or other metal based deposit. Furthermore, an
inner surface of the fluid outlet duct 130 is coated with a copper
or other metal based deposit thereby forming a metallic outlet tube
370 coupling the outlet pad 360 to the annular outlet pad 365. A
pair of solder balls 375 is deposited on the outlet pad 360 and the
solder balls 375 are also held temporarily in place by a flux
paste. In another embodiment a single solder ball may be used
instead of the pair of solder balls 375. In this regard, each of
the solder balls 375, or the single solder ball, is the same size
as the solder balls 310. Also, as shown in the magnified
illustrations of the inlet and outlet pads 340 and 360, a process
of making the substrate 105 (by masking and depositing dielectric
materials and metal conductors) causes a small mound to form around
all the pads 120, 340 and 360. This mound causes the pads 120, 340
and 360 to be in a small recess which in some embodiments may
assist in locating the solder balls 310, 355 and 375 on their
respective pads 120, 340 and 360.
[0028] Referring to FIG. 4 there is illustrated a cross-sectional
side view of a fluid cooled semiconductor die package 400, in
accordance with the first preferred embodiment of the present
invention. The fluid cooled semiconductor die package 400 is the
assembled fluid cooled semiconductor die package 300 after a curing
the epoxy and then performing a solder reflow process on the solder
balls 310, 355 and 375. The die package 300 is heated in an oven to
cure the epoxy 355 and therefore improve the robustness of the
hermetic seal. In this specific embodiment the heat transfer lid
305 is made from thin sheet steel, however any thermally conductive
material can be used. After curing the epoxy 355 a solder reflow
process is performed in another oven in which the solder balls 310,
355 and 375 become soldered to their respective pads 120, 340 and
360.
[0029] The solder reflow process results in the solder balls 310
slightly changing shape and forming solder globules of external
connector solder deposits 405 that are soldered to a respective
external connector pad 120. Also, the solder balls 355 have changed
shape and form inlet solder deposit or solder globule 410 that is
soldered to the inlet pad 340. Similarly, the solder balls 375 have
changed shape and form an outlet solder deposit or solder globule
415 that is soldered to the outlet pad 360. As illustrated, the
globule 410 covers the entrance to the package fluid inlet duct
130. Similarly, the globule 415 covers the exit to the package
fluid outlet duct 135.
[0030] Referring to FIG. 5 there is illustrated an underside plan
view of the fluid cooled semiconductor die package 400. As shown,
the external connector solder deposits 405 form a ball grid array
external connector arrangement 505. Also illustrated are the
globules 410 that cover the entrance to their respective package
fluid inlet ducts 130 and the globules 415 that cover the exit to
their package fluid outlet ducts 135.
[0031] Referring to FIG. 6 there is illustrated cross-sectional
side view of a fluid cooled circuit board system 600, in accordance
with the first preferred embodiment of the present invention. The
system 600 includes a circuit board 605 with mounting pads 610 on a
surface of the circuit board 605. The circuit board 605 also has a
board inlet duct 615 and a board outlet duct 620. There is a board
inlet pad 625 that surrounds an exit of the board inlet duct 615. A
copper deposit, or any other metal-based deposit, forms the board
inlet pad 625. This board inlet pad 625 is an annulus that
surrounds the exit of the board inlet duct 615. Also, an inner
surface of the board inlet duct 615 is coated with a copper or
other metal based deposit thereby forming a metallic tube 630
coupled to the board inlet pad 625.
[0032] There is also a board outlet pad 640 that surrounds an
entrance of the board outlet duct 620. A copper deposit, or any
other metal-based deposit, forms a board outlet pad 640. This board
outlet pad 640 is an annulus that surrounds the entrance of the
board outlet duct 620. Also, an inner surface of the board outlet
duct 620 is coated with a copper or other metal based deposit
thereby forming a metallic tube 645 coupled to the board outlet pad
640.
[0033] The system 600 also includes the fluid cooled semiconductor
die package 400 mounted to the circuit board 605 and the package
400 has undergone a solder reflowing process so that the external
connector solder deposits 405 provide a soldered interconnect
between respective aligned external connector pads 120 and the
mounting pads 610. As a result, the external connector solder
deposits 405 provide a soldered coupling between respective
external connector pads 120 and the mounting pads 610. Also, the
inlet solder deposit 410 couples the inlet pad 340 to the board
inlet pad 625. Similarly, the outlet solder deposit 415 couples the
outlet pad 360 to the board outlet pad 640. As shown, the reflowing
process has caused the solder deposits 410, 415 to change shape and
results in an inlet deposit aperture 655 being formed in the inlet
solder deposit 410 that provides a hermetic coupling between the
board inlet duct 615 and package fluid inlet duct 130. This change
in shape also results in an outlet deposit aperture 660 being
formed in the outlet solder deposit 415 that provides a hermetic
coupling between the board outlet duct 620 and package fluid outlet
duct 135. As will be apparent to a person skilled in the art, the
heat transfer lid 305, in operation, facilitates dissipating heat
generated by the semiconductor die 140.
[0034] Referring to FIG. 7 there is illustrated a cross-sectional
side view of a fluid cooled semiconductor die package 700, in
accordance with a second preferred embodiment of the present
invention. The package 700 is similar to the package 400 except
that there is a different heat transfer lid 705 and gasket 710, and
the epoxy resin 145 provides a liquid resistant protective barrier
for the external terminals 150 of the semiconductor die 140. The
heat transfer lid 705 covers, and encloses the semiconductor die
140 and in operation provides for fluid cooling of the die 140. The
side walls of the heat transfer lid 705 and edges of semiconductor
die 140 provide the lid inlet passage 715 and a lid outlet passage
720 that are in fluid communication, through a heat transfer
chamber 725. Also a ceiling wall 730 of the heat transfer lid 705
and an upper or non-active surface 735 of the semiconductor die 140
forms the heat transfer chamber 725. Accordingly, the heat transfer
lid 705, in operation, facilitates dissipation of heat generated by
the semiconductor die 140.
[0035] Referring to FIG. 8 there is illustrated a fluid cooled
circuit board system 800, in accordance with a third preferred
embodiment of the present invention. The system 800 is similar to
the system 600 except that the fluid cooled semiconductor die
package 400 has been replaced with the fluid cooled semiconductor
die package 700.
[0036] Referring to FIG. 9 there is illustrated a cross-sectional
side view of a stacked fluid cooled circuit board system 900, in
accordance with a fourth preferred embodiment of the present
invention. This stacked fluid cooled circuit board system 900
includes the system 600 in which the circuit board 605 is mounted
(stacked) on an additional substrate 905 upon which is mounted an
additional semiconductor die 910. The additional substrate 905 is
mounted on an additional circuit board 915 that has an additional
board fluid inlet duct 920 and additional board fluid outlet duct
925. The additional substrate 905 has an intermediate inlet fluid
duct 930 with an associated solder deposit 935 with an aperture 940
that provides a hermetic coupling between the intermediate inlet
fluid duct 930 and the additional board inlet fluid duct 920. The
additional substrate 905 also has an intermediate outlet fluid duct
945 with an associated solder deposit 950 with an aperture 955 that
provides a hermetic coupling between the intermediate outlet fluid
duct 945 and the additional board outlet fluid duct 925.
[0037] The stacked fluid cooled circuit board system 900 also
includes a coupling solder deposit 960 with a coupling aperture 965
that provides a hermetic coupling between the intermediate inlet
fluid duct 930 and board inlet duct 615 of the circuit board 605.
Similarly, there is also a coupling solder deposit 970 with a
coupling aperture 975 that provides a hermetic coupling between the
intermediate outlet fluid duct 945 and board outlet duct 620 of the
circuit board 605.
[0038] Referring to FIG. 10 there is illustrated a cross-sectional
side view of a stacked fluid cooled circuit board system 1000, in
accordance with a fifth preferred embodiment of the present
invention. The stacked fluid cooled circuit board system 1000 is
similar to the stacked fluid cooled circuit board system 900 except
that the components of system 600 have been replaced with the
components of system 700.
[0039] Referring to FIG. 11, a flow chart of a method 1100 for
manufacturing a fluid cooled semiconductor die package in
accordance with a sixth preferred embodiment of the present
invention is shown. By way of example only, the method 1100 will be
described with reference to manufacturing the fluid cooled
semiconductor die package 400. The method 1100, at a providing
block 1110, includes providing the package support substrate 105
with a die mounting surface 110 with external connector pads 120
and an opposite package mounting surface 115. The package support
substrate 105 has at least one package fluid inlet duct 130 and at
least one package fluid outlet duct 135 each providing fluid
communication between the die mounting surface 110 and package
mounting surface 115.
[0040] The method 1100, at a mounting block 1120, performs a
process of mounting the semiconductor die 140 on the die mounting
surface 110. At a soldering block 1130, the method 1100 further
performs a process of soldering the external connector solder
deposits 405 to the external connector pads 120, an inlet solder
deposit 410 to the inlet pad 340 that surrounds an entrance of the
package fluid inlet duct 130, and the outlet solder deposit 415 to
the outlet pad 360 that surrounds an exit of the package fluid
inlet duct 135. Each of the external connector solder deposits 405
are formed from a single solder ball, the inlet solder deposit 410
is formed from a single solder ball that is the same size as the
solder balls of a solder deposit 405. Alternatively, the inlet
solder deposit 410 can be formed from at least two solder balls
each being the same size as the solder balls of a solder deposit
405. Similarly, the outlet solder deposit 415 is formed from a
single solder ball that is the same size as than the solder balls
of a solder deposit 405. Alternatively, the outlet solder deposit
415 can be formed from at least two solder balls each being the
same size as the solder balls of a solder deposit 405.
[0041] The method 1100 also includes a process of mounting the heat
transfer lid 305 to the die mounting surface 110 and results in the
manufacture of the fluid cooled semiconductor die package 400 or
any other similar package as will be apparent to a person skilled
in the art.
[0042] Referring to FIG. 12 there is illustrated a cross-sectional
side view of an inlet solder deposit 410 on the package support
substrate 105 of the fluid cooled semiconductor die package 400. As
shown, the package support substrate 105 has been flipped over so
that the package mounting surface 115 is above the die mounting
surface 110. In this specific embodiment a suitable solder
repelling deposit is applied to the inlet tube 350 to keep the
solder from flowing into the package fluid inlet duct 130 during
the soldering process. As shown, the inlet solder deposit 410 has a
width W of 0.65 mm, a height H of 0.31 mm and the package fluid
inlet duct 130 (the internal diameter of the inlet tube 350) has a
diameter D of 0.3 m. Also, each of the two solder balls that form
the solder deposit 410 has a diameter of 0.56 mm. When soldering
the inlet solder deposit 410 to the inlet pad 340, the distance
between the inlet pad 340 and the board inlet pad 625 is 0.27 mm.
These dimensions provide one embodiment for obtaining the inlet
deposit aperture 655 being formed in the inlet solder deposit 410.
Similar dimensions can be used to obtain the outlet deposit
aperture 660 and coupling apertures 965 and 975.
[0043] In operation a piped coolant or refrigerant is supplied to
the board inlet duct 615 or 920 to cool the semiconductor die 140.
The coolant or refrigerant then exits the fluid cooled circuit
board system 600, 800, 900 or 1000 through the board outlet duct
620 or 925. Advantageously, the present invention provides for
hermetically sealing one or more fluid coolant couplings by solder
interconnects. These solder interconnects are formed as part of the
ball grid array or grid array process and therefore may reduce
costs or at least alleviate manufacturing complexity. Also the
tubes, such as the tubes 350 and 370, improve the robustness and
tensile strength of at least some of the hermetic seals and also
these tubes provide a fluid seal to reduce the possibility of fluid
coolants from seeping into the substrates and circuit boards.
[0044] The description of the preferred embodiments of the present
invention has been presented for purposes of illustration and
description, but is not intended to be exhaustive or to limit the
invention to the forms disclosed. It will be appreciated by those
skilled in the art that changes could be made to the embodiments
described above without departing from the broad inventive concept
thereof. It is understood, therefore, that this invention is not
limited to the particular embodiment disclosed, but covers
modifications within the spirit and scope of the present invention
as defined by the appended claims.
* * * * *