U.S. patent application number 11/680470 was filed with the patent office on 2007-06-21 for semiconductor package with heat dissipating structure and method of manufacturing the same.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Jeong-Woo Seo.
Application Number | 20070138625 11/680470 |
Document ID | / |
Family ID | 34909919 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070138625 |
Kind Code |
A1 |
Seo; Jeong-Woo |
June 21, 2007 |
SEMICONDUCTOR PACKAGE WITH HEAT DISSIPATING STRUCTURE AND METHOD OF
MANUFACTURING THE SAME
Abstract
A semiconductor package in which heat is easily dissipated and a
semiconductor chip is not damaged during a molding process, and a
method of manufacturing the same. The semiconductor package with a
heat dissipating structure includes a substrate, a semiconductor
chip, which is mounted on the substrate and electrically connected
with the substrate by bonding means, a heat slug which is adhered
to the semiconductor chip and formed of a thermally conductive
material, and a heat spreader partially exposed to the outside of
the semiconductor package, and which is formed on the heat slug to
be spaced a buffer gap apart from the heat slug.
Inventors: |
Seo; Jeong-Woo;
(Gyeonggi-do, KR) |
Correspondence
Address: |
MARGER JOHNSON & MCCOLLOM, P.C.
210 SW MORRISON STREET, SUITE 400
PORTLAND
OR
97204
US
|
Assignee: |
Samsung Electronics Co.,
Ltd.
416 Maetan-dong, Yeongtong-gu, Suwon-si
Gyeonggi-do
KR
|
Family ID: |
34909919 |
Appl. No.: |
11/680470 |
Filed: |
February 28, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11046514 |
Jan 28, 2005 |
7202561 |
|
|
11680470 |
Feb 28, 2007 |
|
|
|
Current U.S.
Class: |
257/706 ;
257/E23.051; 257/E23.092 |
Current CPC
Class: |
H01L 2224/73265
20130101; H01L 2924/01079 20130101; H01L 2924/1433 20130101; H01L
2924/14 20130101; H01L 24/48 20130101; H01L 23/3128 20130101; H01L
2924/16152 20130101; H01L 2924/00014 20130101; H01L 24/45 20130101;
H01L 2224/48227 20130101; H01L 2224/45124 20130101; H01L 2224/45144
20130101; H01L 2224/45147 20130101; H01L 23/4334 20130101; H01L
2924/181 20130101; H01L 2924/15311 20130101; H01L 2924/14 20130101;
H01L 2924/00 20130101; H01L 2924/181 20130101; H01L 2924/00012
20130101; H01L 2224/45124 20130101; H01L 2924/00014 20130101; H01L
2224/45147 20130101; H01L 2924/00014 20130101; H01L 2924/00014
20130101; H01L 2224/45015 20130101; H01L 2924/207 20130101; H01L
2224/45144 20130101; H01L 2924/00014 20130101 |
Class at
Publication: |
257/706 ;
257/E23.051 |
International
Class: |
H01L 23/34 20060101
H01L023/34 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 2004 |
KR |
2004-5464 |
Claims
1. A semiconductor package with a heat dissipating structure
comprising: a substrate; a semiconductor chip which is mounted on
the substrate and electrically connected with the substrate by
bonding means; a heat slug which is adhered to the semiconductor
chip and formed of a thermally conductive material having a CTE
different from that of the semiconductor chip; a heat spreader
partially exposed to the outside of the semiconductor package and
which is formed on the heat slug to be spaced a buffer gap apart
from the heat slug, and wherein the heat spreader is spaced apart
from the heat slug.
2. The semiconductor package of claim 1, wherein the heat spreader
is formed on the heat slug to be spaced a buffer gap of about 20-30
.mu.m and the heat slug has a thickness of about 200-400 .mu.m.
3. The semiconductor package of claim 1, wherein the heat slug is
made of a highly thermally conductive material selected from the
group consisting of copper, a copper alloy, aluminum, an aluminum
alloy, steel, stainless steel, and a combination thereof.
4. The semiconductor package of claim 1, wherein the heat slug is
made of a thermally conductive material selected from the group
consisting of ceramic, an insulator and a semiconductor
material.
5. The semiconductor package of claim 1, wherein the heat spreader
comprises: an upper plate portion having one surface exposed to the
outside of the semiconductor package and another surface formed on
the heat slug to be spaced a predetermined distance apart from the
heat slug; and a support which is formed on a lower surface of an
edge of the upper plate portion and supports the upper plate
portion on the substrate.
6. The semiconductor package of claim 1, wherein the heat spreader
is made of a highly thermally conductive material selected from the
group consisting of copper, a copper alloy, aluminum, an aluminum
alloy, steel, stainless steel, and a combination thereof.
7. The semiconductor package of claim 6, wherein the upper plate
portion of the heat spreader has a thickness of about 100-200
.mu.m.
8. The semiconductor package of claim 1, wherein the semiconductor
chip and the heat slug are adhered by an adhesive and the adhesive
is an electric insulator and a thermal conductor.
9. The semiconductor package of claim 1, wherein the bonding means
is a bonding wire.
10. The semiconductor package of claim 1, wherein the heat slug has
a CTE smaller than that of the semiconductor chip.
11. A semiconductor package with a heat dissipating structure
comprising: a substrate; a semiconductor chip which is mounted on
the substrate and electrically connected with the substrate by
bonding means; a heat slug which is adhered to the semiconductor
chip and formed of a thermally conductive material having a thermal
conductivity being higher than the semiconductor chip; a heat
spreader partially exposed to the outside of the semiconductor
package and which is formed on the heat slug to be spaced a buffer
gap apart from the heat slug, and wherein the heat spreader is
spaced apart from the heat slug.
12. The semiconductor package of claim 11, wherein the heat
spreader is formed on the heat slug to be spaced a buffer gap of
about 20-30 .mu.m and the heat slug has a thickness of about
200-400 .mu.m.
13. The semiconductor package of claim 11, wherein the heat slug is
made of a highly thermally conductive material selected from the
group consisting of copper, a copper alloy, aluminum, an aluminum
alloy, steel, stainless steel, and a combination thereof.
14. The semiconductor package of claim 11, wherein the heat slug is
made of a thermally conductive material selected from the group
consisting of ceramic, an insulator and a semiconductor
material.
15. The semiconductor package of claim 11, wherein the heat
spreader comprises: an upper plate portion having one surface
exposed to the outside of the semiconductor package and another
surface formed on the heat slug to be spaced a predetermined
distance apart from the heat slug; and a support which is formed on
a lower surface of an edge of the upper plate portion and supports
the upper plate portion on the substrate.
16. The semiconductor package of claim 11, wherein the heat
spreader is made of a highly thermally conductive material selected
from the group consisting of copper, a copper alloy, aluminum, an
aluminum alloy, steel, stainless steel, and a combination
thereof.
17. The semiconductor package of claim 16, wherein the upper plate
portion of the heat spreader has a thickness of about 100-200
.mu.m.
18. The semiconductor package of claim 11, wherein the
semiconductor chip and the heat slug are adhered by an adhesive and
the adhesive is an electric insulator and a thermal conductor.
19. The semiconductor package of claim 18, wherein the adhesive is
thermally conductive resin.
20. The semiconductor package of claim 11, wherein the bonding
means is a bonding wire.
Description
[0001] This is a Divisional of U.S. patent application Ser. No.
11/046,514, filed on Jan. 28, 2005, now pending, which claims
priority of Korean Patent Application No. 10-2004-05464, filed on
Jan. 28, 2004 in the Korean Intellectual Property Office, the
disclosures of which are incorporated herein in their entirety by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a semiconductor package
with a heat dissipating structure and a method of manufacturing the
same, and more particularly, to a semiconductor package with a heat
dissipating structure and a method of manufacturing the same for
preventing malfunction of a semiconductor chip due to a hindrance
in thermal dissipation when needing to rapidly dissipate heat that
is generated during a high-speed operation of the semiconductor
chip to the outside of the package using a heat spreader and a heat
slug.
[0004] 2. Description of the Related Art
[0005] Generally, thermal dissipation is an important
characteristic of semiconductor packages used by high-speed,
high-frequency application specific integrated circuit (ASIC)
products or high-speed semiconductor memory devices such as dynamic
random access memories (DRAMs) and static random access memories
(SRAMs).
[0006] There has recently been a growing demand for high-speed and
high-output semiconductor devices, and semiconductor packages
accommodate such demand. Semiconductor packages now being developed
or having been developed are roughly classified into two types in
terms of a power end demanding high-output: a plastic package type
in which a heat sink is usually adhered to a power transistor or a
module device, and a heat dissipating type in which heat generated
during the operation of electronic components is easily dissipated
by using a metal housing for a ceramic substrate.
[0007] FIG. 1 is a cross-sectional view of a conventional ball grid
array (BGA) package 100.
[0008] As shown in FIG. 1, the BGA package 100 includes a substrate
110, a semiconductor chip 130 and a heat sink 170.
[0009] The semiconductor chip 130 is adhered to an upper surface of
the substrate 110 and electrically connected with the substrate 110
by bonding wires 140. The BGA package 100 having the
above-described construction has the heat sink 170 for effectively
dissipating heat generated to the outside the BGA package 100, when
operating electronic components formed within the semiconductor
chip 130. As shown in FIG. 1, the heat sink 170 is located at an
upper part of the semiconductor chip 130 and one surface of the
heat sink 170 is exposed to the outside of the BGA package 100.
Thus, the heat generated from the semiconductor chip 130 can be
easily dissipated to the outside of the BGA package 100.
[0010] After the heat sink 170 is formed on the semiconductor chip
130, the bonding wires 140 and the heat sink 170 on the substrate
110 are encapsulated by insulating encapsulant resin 180. As
described above, the heat sink 170 is encapsulated to expose one
surface thereof to the outside of the BGA package 100.
[0011] Solder balls 190 are formed on a lower surface of the
substrate 110 on which the semiconductor chip 130 is mounted.
[0012] The BGA package 100 is provided with the conventional heat
sink 170 to ensure improved thermal properties compared to another
conventional BGA package without a heat sink. The heat sink 170 is
exposed to a surface of the BGA package 100 so that the heat
generated when operating the electric components formed in the
semiconductor chip 130 is easily dissipated to the outside of the
BGA package 100.
[0013] In the BGA package 100 including the conventional heat sink
170, some of the heat generated from the semiconductor chip 130 is
dissipated to the outside of the BGA package 100 through the
substrate 110 located at a lower part of the semiconductor chip
130, and the rest is dissipated to the outside of the BGA package
100 through the heat sink 170 located at the upper part of the
semiconductor chip 130.
[0014] The heat sink 170 is formed on the semiconductor chip 130 to
be spaced a distance (L1 in FIG. 1) of about 300-400 .mu.m apart
from the semiconductor chip 130 so as not to damage the bonding
wires 140. The gap L1 is filled with the insulating encapsulant
resin 180. Generally, a highly thermally conductive material, for
example a metal material, is used as the heat sink 170.
Disadvantageously, the insulating encapsulant resin 180 is known to
have a low thermal conductivity, however.
[0015] Accordingly, in the conventional BGA package 100 the
semiconductor chip 130 is not directly in contact with the heat
sink 170, so most of the heat generated from the semiconductor chip
130 is transferred to the heat sink 170 in the form of radiant
heat. Accordingly, thermal dissipation is not efficient with the
conventional BGA package structure.
SUMMARY OF THE INVENTION
[0016] The invention provides a semiconductor package with a heat
dissipating structure in which heat generated by the operation of
electronic components formed in a semiconductor chip is efficiently
dissipated by providing various heat dissipating means; the
reliability of the operation of the electronic components can be
improved; and the semiconductor chip can be prevented from being
pressed by a mold when the semiconductor package is encapsulated by
encapsulant resin after arranging the heat dissipating means. The
invention also provides a method of manufacturing the semiconductor
package.
[0017] In accordance with an aspect of the invention, there is
provided a semiconductor package with a heat dissipating structure
comprising a substrate; a semiconductor chip mounted on the
substrate and electrically connected thereto; a heat slug coupled
to the semiconductor chip and formed of a thermally conductive
material; and a heat spreader partially exposed to the outside of
the semiconductor package and formed on the heat slug to be spaced
apart from the heat slug.
[0018] In accordance with another aspect of the invention, there is
provided a method of manufacturing the semiconductor package with a
heat dissipating structure comprising electrically coupling a
semiconductor chip to the substrate; coupling a heat slug made of a
thermally conductive material to an upper surface of the
semiconductor chip; and forming a heat spreader over an upper part
of the heat slug to be spaced apart from the heat slug.
[0019] Other objectives, advantages, and features of the invention
will become more apparent from the following detailed description
when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above features and advantages of the present invention
will become more apparent by describing in detail exemplary
embodiments thereof with reference to the attached drawings.
[0021] FIG. 1 is a cross-sectional view of a conventional ball grid
array package (BGA).
[0022] FIGS. 2A through 2E are cross-sectional views showing a
method of manufacturing a semiconductor package according to the
present invention.
[0023] FIGS. 3A through 3C are perspective views showing a heat
slug applied in the semiconductor package according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] 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 the specification.
[0025] Semiconductor packages according to embodiments of the
present invention constitute high-frequency microprocessors or ASIC
products, or high-speed semiconductor memory devices such as DRAMs
or SRAMs. Such devices mostly have input/output terminals with
multiple pins. Semiconductor packages constituting such devices can
be classified according to the multiple pin configurations, for
example, a plastic or ceramic pin grid array (PGA) package, a land
grid array (LGA) package, a ball grid array (BGA) package, a quad
flat package, a lead frame package, and the like.
[0026] Further, substrates that can be applied to the semiconductor
package according to the present invention include a printed
circuit board, a ceramic substrate, a metal substrate, a silicon
substrate, and the like, which can be applied to semiconductor
packages such as a PGA package, a LGA package, a BGA package, a
quad flat package and a lead frame package.
[0027] Hereinafter, a BGA package is used as the semiconductor
package and a printed circuit board is used as the substrate in the
embodiment of the present invention for convenience of
explanation.
[0028] The embodiment of the present invention is explained with
reference to FIGS. 2A to 2E.
[0029] FIGS. 2A to 2E are cross-sectional views showing a method of
manufacturing a semiconductor package according to a preferred
embodiment of the present invention. This method and the figures
will be explained later.
[0030] As shown in FIG. 2E, a semiconductor package 200 according
to the illustrative embodiment of the present invention includes a
substrate 210, a semiconductor chip 230, a heat slug 260, and a
heat spreader 270.
[0031] Here, the substrate 210 has a plurality of solder balls 290
formed on a lower part of the substrate 210. Coupling the solder
balls 290 to the substrate 210 can be performed at any stage,
regardless of the order of formation of the semiconductor package
200.
[0032] The semiconductor chip 230 is mounted on an upper surface of
the substrate 210 and adhered to the substrate 210 by an adhesive
220. Here, a silver paste is typically used as the adhesive 220.
The semiconductor chip 230 is a chip having a high-frequency
microprocessor or ASIC product or a high-speed memory device, e.g.,
a DRAM or SRAM, embodied therein.
[0033] Bonding pads (not shown) of the semiconductor chip 230 and
electrode pads (not shown) of the substrate 210 are electrically
connected to each other by bonding means 240. Although the bonding
wires are used as the bonding means 240 in the illustrative
embodiment of the present invention, the present invention is not
limited thereto. That is, the semiconductor chip 230 and the
substrate 210 can be electrically connected to each other by flip
chip bonding, for example. The bonding wires may be formed of gold,
copper, aluminum or a combination thereof.
[0034] The heat slug 260 is made of a thermally conductive material
and adhered to an upper part of the semiconductor chip 230. Here,
the heat slug 260 is preferably made of a highly thermally
conductive material selected from the group consisting of copper, a
copper alloy, aluminum, an aluminum alloy, steel, stainless steel,
and a combination thereof. Further, the heat slug 260 may be made
of one selected from the group consisting of ceramic, an insulator
or a semiconductor material. The heat slug 260 may be formed by
casting, forging or press-molding.
[0035] The heat slug 260 can be adhered to the semiconductor chip
230 using an adhesive 250. Here, the adhesive 250 must meet several
requirements, including not affecting the surface of the
semiconductor chip 230 and properly supporting the heat slug 260.
The adhesive 250 is an electric insulator, preferably a heat
conductor. Thermally conductive resin is also preferably used as
the adhesive 250. More preferably, silicon rubber or a buffer
binder consisting of an elastomer material is used as the adhesive
250. The adhesive 250 mitigates the transfer of external impact to
the semiconductor chip 230 so that damage of the semiconductor chip
230 due to external impacts is suppressed. Further, the heat slug
260 can be prevented from being peeled off due to a difference in
coefficients of thermal expansion between the heat slug 260 and the
semiconductor chip 230.
[0036] Thermo-plastic adhesive epoxy, thermo-setting adhesive
epoxy, thermally conductive epoxy, an adhesive tape, or a
combination thereof can also be used as the adhesive 250.
[0037] In the illustrative embodiment of the present invention, the
heat slug 260 disposed between the semiconductor chip 230 and the
heat spreader 270, which will be described below, preferably has a
thickness L2 of about 200-400 .mu.m.
[0038] FIGS. 3A through 3C are perspective views showing the heat
slug 260 according to the illustrative embodiment of the present
invention. As shown in FIGS. 3A through 3C, the heat slug 260 may
have a planar surface 262. Further, one surface of the heat slug
260 has protrusions 264 or grooves 266 so that the effect of
dissipating heat generated by the semiconductor chip 230 can be
maximized.
[0039] As shown in FIG. 2E, the heat spreader 270 is formed on the
heat slug 260 to be spaced a buffer gap L3 apart from the heat slug
260. Preferably, the buffer gap L3 is wide enough to serve as a
buffer between the heat spreader 270 and the heat slug 260, for
example, about 100 .mu.m or less. Here, the buffer gap L3 plays a
role as a buffer to absorb a pressure applied during encapsulation
of the semiconductor chip 230, and transfers the heat of the heat
slug 260 to the heat spreader 270. Damage which may be applied to
the semiconductor chip 230 due to a mold pressure applied during
encapsulation of elements formed on the substrate 210 using
insulating encapsulant resins 280 can be prevented by providing a
thin buffer gap L3 between the heat slug 260 and the heat spreader
270. In order for the buffer gap L3 to perform such functions, the
buffer gap L3 is more preferably in a range of about 20-30
.mu.m.
[0040] The heat spreader 270 includes an upper plate portion 272
and a support 274. The upper plate portion 272 is formed on the
heat slug 260 and spaced the predetermined buffer gap L3 apart from
the heat slug 260. The support 274 is formed on a lower surface of
and at an edge of the upper plate portion 272, is adhered to the
substrate 210, and supports the upper plate portion 272. Here, the
upper plate portion 272 of the heat spreader 270 has a thickness of
about 100-200 .mu.m and a flat shape. It is preferable that the
heat spreader 270 is made of a highly thermally conductive material
selected from the group consisting of copper, a copper alloy,
aluminum, an aluminum alloy, steel, stainless steel, and a
combination thereof. The heat spreader 270 can be manufactured by
casting, forging, press-molding, and the like.
[0041] The insulating encapsulant resin 280 encapsulates the
semiconductor chip 230, the heat slug 260 and the heat spreader 270
mounted on the substrate 210 to protect them from external impact.
As shown in FIG. 2E, one surface of the upper plate portion 272 of
the heat spreader 270 is exposed to effectively dissipate the heat
from the heat spreader 270 to the outside of the package 200. Thus,
the substrate 210, the semiconductor chip 230, the heat slug 260
and the support 274 of the heat spreader 270 are encapsulated by
the insulating encapsulant resin 280. For example, epoxy molding
compound (EMC) can be used as the insulating encapsulant resin
280.
[0042] In the above-described embodiment of the present invention,
an electric signal output from an external system board (not shown)
is input to the semiconductor chip 230 via the solder balls 290,
the substrate 210 and the bonding means 240. Conversely, an
electric signal output from the semiconductor chip 230 is input to
the external system board via the bonding means 240, the substrate
210 and the solder balls 290. The semiconductor chip 230 may be
driven at a high speed through the above-described input and output
processes. The amount of heat generated from the semiconductor chip
230 may be proportional to the speed at which the semiconductor
chip 230 is driven.
[0043] In the present invention, as described above, the heat slug
260 and the heat spreader 270 having a high thermal conductivity
are disposed on the upper part of the semiconductor chip 230. Thus,
although a large amount of heat is generated from the semiconductor
chip 230 that may operate at a high speed, the heat can be more
easily dissipated using the heat slug 260 and the heat spreader
270. As a result, malfunction of the semiconductor chip 230 due to
a hindrance in thermal dissipation can be prevented.
[0044] Hereinafter, a method of manufacturing the semiconductor
package according to the illustrative embodiment of the present
invention is explained in reference to FIGS. 2A through 2E.
[0045] As shown in FIG. 2A, the semiconductor chip 230 is adhered
to the substrate 210 using an adhesive 220, e.g., silver paste.
Electrode pads (not shown) of the substrate 210 are electrically
connected with bonding pads (not shown) of the semiconductor chip
230 by the bonding means 240.
[0046] As shown in FIG. 2B, the adhesive 250 is applied to the
upper surface of the semiconductor chip 230, followed by adhering
the heat slug 260 to the semiconductor chip 230, thereby preventing
I/O bonding pads (not shown) formed on the upper surface of the
semiconductor chip 230 from being damaged.
[0047] As shown in FIG. 2C, the heat spreader 270 is formed on the
heat slug 260 to be spaced the predetermined buffer gap L3 apart
from the heat slug 260.
[0048] As shown in FIG. 2D, the semiconductor chip 230, the bonding
means 240, the heat slug 260, and the heat spreader 270 are
protected by molding using the insulating encapsulant resin 280,
for example, EMC. Here, in order to ensure thermal dissipation
efficiency, the upper surface of the heat spreader 270 is not
covered by the insulating encapsulant resin 280.
[0049] As shown in FIG. 2E showing a step of forming external I/O
terminals, after completing the encapsulating, the external I/O
terminals of the semiconductor package 200, that is, the solder
balls 290 shown in FIG. 2E, are formed. It is preferable, but not
mandatory, that the forming of the external I/O terminals is
performed after the encapsulating. The external I/O terminals can
be optionally formed regardless of the order of formation of the
semiconductor package 200.
[0050] While certain exemplary embodiments have been described and
shown in the accompanying drawings, it will be appreciated that
various changes in form and details may be made therein without
departing from the spirit and scope of the present invention as
defined by the following claims. Therefore, it is to be understood
that the above described embodiment is for purposes of illustration
only and not to be construed as a limitation of the invention.
[0051] As described above, in accordance with a semiconductor
package with a heat dissipating structure and a method of
manufacturing the same according to the present invention, heat
generated from a semiconductor chip can be quickly dissipated by a
heat slug and a heat spreader made of a highly thermally conductive
material.
[0052] Further, the semiconductor chip can be stably protected in
an encapsulating process using insulating encapsulant resin by an
adhesive between the heat slug and the semiconductor chip and a gap
between the heat slug and the heat spreader. That is, since thermal
dissipation function and a protective function of the semiconductor
chip can be simultaneously carried out in the semiconductor
package, according to the present invention, excellent performance
of the semiconductor chip can be maintained for a long time.
* * * * *