Semiconductor device package

A semiconductor device package includes a semiconductor die and an anisotropic thermal conductive structure. The semiconductor die includes a first surface, a second surface opposite to the first surface and edges connecting the first surface to the second surface. The anisotropic thermal conductive structure has different thermal conductivities in different directions. The anisotropic thermal conductive structure includes at least two pairs of film stacks, and each pair of the film stacks comprises a metal film and a nano-structural film alternately stacked. The anisotropic thermal conductive structure comprises a first thermal conductive section disposed on the first surface of the semiconductor die, and the first thermal conductive section is wider than the semiconductor die.

BACKGROUND

1. Technical Field

The present disclosure relates to a semiconductor device package with high thermal dissipation effect and method for manufacturing the same.

2. Description of the Related Art

The semiconductor industry has seen growth in an integration density of a variety of different electronic components in a semiconductor device package. This increased integration density often results in an increased power density in the semiconductor device packages. As the power density of semiconductor device packages grows, heat dissipation becomes an issue to be addressed.

SUMMARY

In some embodiments, a semiconductor device package includes a semiconductor die and an anisotropic thermal conductive structure. The semiconductor die includes a first surface, a second surface opposite to the first surface and edges connecting the first surface to the second surface. The anisotropic thermal conductive structure has different thermal conductivities in different directions. The anisotropic thermal conductive structure includes at least two pairs of film stacks, and each pair of the film stacks comprises a metal film and a nano-structural film alternately stacked. The anisotropic thermal conductive structure comprises a first thermal conductive section disposed on the first surface of the semiconductor die, and the first thermal conductive section is wider than the semiconductor die.

In some embodiments, a semiconductor device package includes a semiconductor die, a first thermal conductive section and a second thermal conductive section. The semiconductor die includes a first surface, a second surface opposite to the first surface and edges connecting the first surface to the second surface. The first thermal conductive section is disposed on the first surface of the semiconductor die. The first thermal conductive section includes at least two pairs of film stacks, and each pair of the film stacks of the first thermal conductive section includes a metal film and a nano-structural film alternately stacked. The second thermal conductive section is adjacent to at least one of the edges of the semiconductor die and connected to the first thermal conductive section.

In some embodiments, a semiconductor device package includes a lead frame, a semiconductor die and an encapsulant. The lead frame includes a die pad, a plurality of supporting bars extending from the die pad, and a plurality of fingers spaced apart the die pad. The lead frame includes at least two pairs of film stacks, and each pair of the film stacks of the lead frame includes a metal film and a nano-structural film alternately stacked. The semiconductor die is disposed on the die pad and electrically connected to the fingers. The encapsulant encapsulates the lead frame and the semiconductor die.

DETAILED DESCRIPTION

As used herein the term “active surface” may refer to a surface of a semiconductor die on which contact terminals such as contact pads are disposed, and the term “inactive surface” may refer to another surface of the semiconductor die opposite to the active surface on which no contact terminals are disposed. As used herein the term “nano-structural film” may refer to a film including or consisting essentially of nanostructures of nanometric scale. As used herein the term “anisotropic thermal conductive structure” may refer to a thermal conductive structure having a thermal conductivity in a specific direction different from that in another direction.

Some embodiments of the present disclosure provide semiconductor device packages with anisotropic thermal conductive structures. The anisotropic thermal conductive structures have anisotropic thermal conductive characteristic that helps transfer heat generated by the semiconductor die in a more efficient way with less thermal resistance, and thus heat dissipation of the semiconductor device package can be improved.

FIG. 1is a schematic top view of a semiconductor electronic device package1in accordance with some embodiments of the present disclosure,FIG. 1Ais a schematic cross-sectional view of a semiconductor device package1taken in a line A-A′ inFIG. 1, andFIG. 1Bis a schematic enlarged cross-sectional view of an anisotropic thermal conductive structure20in accordance with some embodiments of the present disclosure. For the purpose of clarity, some components may not be shown inFIG. 1,FIG. 1AandFIG. 1B. As shown inFIG. 1,FIG. 1AandFIG. 1B, the semiconductor device package1includes a semiconductor die10and an anisotropic thermal conductive structure20. The semiconductor die10includes a first surface101, a second surface102opposite to the first surface101, and edges10E connecting the first surface101to the second surface102. In some embodiments, the second surface102may be an active surface on which contact terminals10P such as contact pads are disposed, and the first surface101may be an inactive surface on which no contact terminals are disposed. The semiconductor die10may include a polygonal shape such as a rectangular shape with four edges10E. The semiconductor die10may include an active die such as a logic die or a system on chip (SOC), a passive die, or a combination thereof.

The anisotropic thermal conductive structure20has different thermal conductivities in different directions, e.g., a thermal conductivity (also referred to a coefficient of thermal conductivity) of the anisotropic thermal conductive structure20in a specific direction may be different from a thermal conductivity of the anisotropic thermal conductive structure20in another direction. The anisotropic thermal conductive structure20may include a plurality of sections directly or indirectly connected to each other, and the sections may have similar or different anisotropic thermal conductive characteristics. As shown inFIG. 1B, the anisotropic thermal conductive structure20may include at least two pairs20P of film stacks, and each pair20P of the film stacks includes a metal film20A and a nano-structural film20B alternately stacked. In some embodiments, the metal film20A and the nano-structural film20B have different characteristics. For example, the thermal conductivity of the nano-structural film20B may be higher than that of the metal film20A, and the structural strength of the metal film20A may be higher than that of the nano-structural film20B. The metal film20A may be an isotropic thermal conductive film having a substantially equal thermal conductivity in different directions. The nano-structural film20B may be an anisotropic thermal conductive film having a thermal conductivity in a specific direction different from that in another direction. The metal films20A and the nano-structural films20B can be stacked in different manners to make the anisotropic thermal conductive structure20have a higher thermal conductivity in one direction, and a lower thermal conductivity in another direction. For example, the thermal conductivity in a lateral direction may be higher than that in a vertical direction in case the nano-structural films20B and the metal films20A are stacked in the vertical direction. Alternatively, the thermal conductivity in the vertical direction may be higher than that in the lateral direction in case the nano-structural films20B and the metal films20A are stacked in the lateral direction. In some embodiments, the metal film20A may include, but is not limited to, a copper film such as a copper foil, and the nano-structural film20B may include, but is not limited to, a graphene film.

The anisotropic thermal conductive structure20includes a first thermal conductive portion22disposed on the first surface101of the semiconductor die10. In some embodiments, the film stacks of the first thermal conductive section22are stacked substantially in a vertical direction Dz perpendicular to the first surface101of the semiconductor die10, and a thermal conductivity of the first thermal conductive section22substantially in lateral directions Dx and Dy is greater than that of the first thermal conductive section22substantially in the vertical direction Dz. The thermal conductivity of the graphene film may be substantially equal in any lateral directions e.g., Dx and Dy in XY plane in case the film stacks of the first thermal conductive section22are stacked substantially in the vertical direction Dz. The first thermal conductive section22is wider than the semiconductor die10and laterally protrudes out at least one of the edges of the semiconductor die10, such that the heat generated by the semiconductor die10during operation can be rapidly laterally transferred. Accordingly, the temperature of the semiconductor device package1during operation can be lowered. The outer surface22S of the first thermal conductive section22may include an even surface. Alternatively, the outer surface22S of the first thermal conductive section22may include a rough surface to increase heat dissipation efficiency. In some embodiments, an outer surface22S of the first thermal conductive section22can be exposed to environment to increase thermal radiation heat transfer. The outer surface22S of the first thermal conductive section22may include an even surface. Alternatively, the outer surface22S of the first thermal conductive section22may include a rough surface to increase heat dissipation efficiency. In some other embodiments, the outer surface22S of the first thermal conductive section22can be connected to a heat dissipation structure to further enhance heat dissipation effect. Examples of the heat dissipation structure may include heat sink, air cooling structure, water cooling structure, fan or other suitable active and/or passive type heat dissipation structures.

In some embodiments, the thermal radiation ability of the nano-structural film20B is higher than that of the metal film20A, and thus the nano-structural film20B can be the exterior film of the anisotropic thermal conductive structure20to provide better thermal radiation effect. In some embodiments, the metal film20A may be configured as a support film of the nano-structural film20B, and the thickness of the metal film20A may be larger than the thickness of the nano-structural film20B. The thickness of the metal film20A may be about three times thicker than the thickness of the nano-structural film20A. For example, the thickness of the metal film20A may be about 15 micrometers, and the thickness of the nano-structural film20B is about 5 micrometers. The number of the pair20P of film stacks can be modified based on structure strength and heat dissipation considerations. In some embodiments, the anisotropic thermal conductive structure20may include 15 or more pairs20P of film stacks. Since the thermal conductivity and thermal radiation ability of the nano-structural film20B are higher than that of the metal film20A, the anisotropic thermal conductive structure20may include an extra nano-structural film20B, such that the outer sides of the anisotropic thermal conductive structure20are both the nano-structural films20B. By way of example, the lateral thermal conductivity of the first thermal conductive portion22is about 703 W/mk, and the vertical thermal conductivity of the first thermal conductive portion22is about 481 W/mk when the anisotropic thermal conductive structure20includes fifteen pairs20P of copper films and graphene films.

In some embodiments, the semiconductor device package1may further include a thermal interface material (TIM)32disposed between the first surface101of the semiconductor die10and the first thermal conductive section22. The thermal interface material32may be adhesive, and in contact with the first thermal conductive section22and the semiconductor die10to couple the first thermal conductive section22to the semiconductor die10. The thermal interface material32may also be configured as a buffer layer to cushion the shock or force during mounting the anisotropic thermal conductive structure20. The thermal interface material32may include a polymeric material. The higher and anisotropic thermal conductivity of the first thermal conductive section22can help compensate the thermal resistance of the thermal interface material32, and thus can improve overall heat dissipation of the semiconductor device package1.

The anisotropic thermal conductive structure20further includes a second thermal conductive section24adjacent to at least one of the edges10E of the semiconductor die10, and the second thermal conductive section24and the at least one of the edges10E of the semiconductor die10are spaced with a gap G. In some embodiments, the second thermal conductive section24includes a ring structure connecting the first thermal conductive section22and surrounding all the edges10E of the semiconductor die10. In some embodiments, the first thermal conductive section22and the second thermal conductive section24may collectively form a hat structure that enclose the first surface101and the edges10E of the semiconductor die10to provide heat dissipation as well as protection to the semiconductor die10. In some embodiments, the film stacks of the second thermal conductive section24may be stacked substantially in an oblique direction Db different from the vertical direction Dz and the lateral directions Dx and Dy as the first thermal conductive section22, and the first thermal conductive section22and the second thermal conductive section24can be integrally formed.

In some embodiments, the semiconductor device package1may further include a substrate40disposed on the second surface102of the semiconductor die10. The substrate40includes a top surface401connected to the second thermal conductive section24, a bottom surface402opposite to the top surface401, and edges40E connecting the top surface401to the bottom surface402. In some embodiments, the second thermal conductive section24may be grounded through the substrate40to provide shielding effect to the semiconductor die10. In some embodiments, the semiconductor device package1may further include another thermal interface material34disposed between the second thermal conductive section24and the substrate40to bond the second thermal conductive section24and the substrate40. The thermal interface material34and the thermal interface material32may include the same or different materials.

The substrate40may include a circuit substrate having circuitry42to build external connections for the semiconductor die10. Examples of the substrate40may include a package substrate, a fan-out circuit layer, a redistribution layer (RDL), an interposer or the like. In some embodiments, a plurality of conductive structures12such as solder bumps are disposed between and electrically connected the electrical terminals10P of the semiconductor die10and the circuitry42of the substrate40. In some embodiments, an encapsulant14such as an underfill and/or a molding compound may encapsulate the edges10E and/or the second surface102of the semiconductor die10. In some other embodiments, the first surface101may be an active surface, and the semiconductor die10may be electrically connected to the substrate40through wire bonding or the like.

In some embodiments, the semiconductor device package1may further include a circuit board50such as a printed circuit board (PCB) disposed on the bottom surface402of the substrate40, and electrical conductors52such as solder balls disposed between and electrically connected to the substrate40and the circuit board50.

In the aforementioned embodiments, the anisotropic thermal conductive structure20including multiple pairs20P of metal films20A and nano-structural films20B has higher thermal conductivity in all lateral directions such as Dx and Dy in XY plane, and thus the heat generated by the semiconductor die10can be efficiently transferred from the first thermal conductive section22and the second thermal conductive section24to the substrate40. In addition, the nano-structural film20B of the anisotropic thermal conductive structure20has better thermal radiation effect, and thus the heat generated by the semiconductor die10can also be transferred by thermal radiation. Furthermore, the anisotropic thermal conductive structure20can further provide protection and/or shielding for the semiconductor die10.

The semiconductor device packages and manufacturing methods of the present disclosure are not limited to the above-described embodiments, and may be implemented according to other embodiments. To streamline the description and for the convenience of comparison between various embodiments of the present disclosure, similar components of the following embodiments are marked with same numerals, and may not be redundantly described.

FIG. 2is a schematic cross-sectional view of a semiconductor device package2in accordance with some embodiments of the present disclosure. As shown inFIG. 2, in contrast to the semiconductor device package1, the film stacks of the first thermal conductive section22and the second thermal conductive section24are stacked in different directions. By way of an example, the film stacks of the first thermal conductive section22are stacked substantially in the vertical direction Dz, and the film stacks of the second thermal conductive section24are stacked substantially in the lateral direction Dx. Thus, the thermal conductivity of the first thermal conductive section22substantially in the lateral direction Dx is larger than that of the first thermal conductive section22substantially in the vertical direction Dz, while the thermal conductivity of the second thermal conductive section24substantially in the vertical direction Dz is larger than that of the second thermal conductive section24substantially in the lateral directions Dx and Dy. Accordingly, heat generated by the semiconductor die10can be efficiently transferred from the first thermal conductive section22and the second thermal conductive section24to the substrate40. In some embodiments, the first thermal conductive section22and the second thermal conductive section24are formed individually, and can be connected directly or indirectly through a thermal interface material36. The thermal interface material36may include similar material as the thermal interface material32or34.

FIG. 3is a schematic cross-sectional view of a semiconductor device package3in accordance with some embodiments of the present disclosure. As shown inFIG. 3, the film stacks of the first thermal conductive section22and the second thermal conductive section24are both stacked in substantially in the lateral direction Dx, for example. Thus, the thermal conductivity of the first thermal conductive section22and the thermal conductivity of the second thermal conductive section24substantially in the vertical direction Dz are larger than that of the first thermal conductive section22and the second thermal conductive section24substantially in the lateral direction Dx. Accordingly, a portion of heat generated by the semiconductor die10can be efficiently transferred from the first thermal conductive section22to the environment or an extra heat dissipation structure disposed on the outer surface22S of the first thermal conductive section22. Another portion of heat generated by the semiconductor die10can be transferred from the first thermal conductive section22and the second thermal conductive section24to the substrate40. In some embodiments, the first thermal conductive section22and the second thermal conductive section24are formed individually, and can be connected directly or indirectly.

FIG. 4is a schematic cross-sectional view of a semiconductor device package4in accordance with some embodiments of the present disclosure. As shown inFIG. 4, in contrast to the semiconductor device package3, the anisotropic thermal conductive structure20of the semiconductor device package4may further include a third thermal conductive section26adjacent to at least one of the edges40E of the substrate40and connected to the second thermal conductive section24. In some embodiments, the third thermal conductive section26may surround all edges40E of the substrate40. The third thermal conductive section26can be further connected to the circuit board50directly or through a thermal interface material38. In some embodiments, the film stacks of the first thermal conductive section22and the third thermal conductive section26can be stacked in the same direction such as substantially in the lateral direction Dx, while the film stacks of the second thermal conductive section24can be stacked substantially in a different direction such as the vertical direction Dz. Accordingly, a portion of heat generated by the semiconductor die10can be efficiently transferred from the first thermal conductive section22to the environment or an extra heat dissipation structure disposed on the outer surface22S of the first thermal conductive section22. Another portion of heat generated by the semiconductor die10can be transferred from the first thermal conductive section22and the second thermal conductive section24to the substrate40, and transferred from the third thermal conductive section26to the circuit board50. In some embodiments, the first thermal conductive section22, the second thermal conductive section24and the third thermal conductive section26can be formed individually, and can be connected directly or indirectly.

FIG. 5is a schematic top view of a semiconductor electronic device package5in accordance with some embodiments of the present disclosure, andFIG. 5Ais a schematic cross-sectional view of a semiconductor device package5taken in a line B-B′ inFIG. 5. As shown inFIG. 5andFIG. 5A, in contrast to the semiconductor device package4, the anisotropic thermal conductive structure20of the semiconductor device package5may further include a fourth thermal conductive section28disposed on the circuit board50and connected to the third thermal conductive section26. The film stacks of the fourth thermal conductive section28are stacked substantially in the vertical direction Dz, such that the thermal conductivity of the fourth thermal conductive section28in the lateral direction Dx is larger than that in the vertical direction Dz. The fourth thermal conductive section28extends in the lateral direction Dx, and thus the overlapping area between the fourth thermal conductive section28and the circuit board50can be enlarged. Accordingly, heat transfer from the fourth thermal conductive section28to the circuit board50can be increased. In some embodiments, the second thermal conductive section24includes a ring structure connecting the first thermal conductive section22and surrounding all the edges10E of the semiconductor die10, and the fourth thermal conductive section28includes a ring structure connecting the third thermal conductive section26and surrounding all the edges40E of the substrate40. The film stacks of the first thermal conductive section22, the second thermal conductive section24, the third thermal conductive section26and the fourth thermal conductive section28are alternate, and thus heat generated by the semiconductor die10can be transferred in an efficient way from different sections of the anisotropic thermal conductive structure20to the substrate40and the circuit board50.

FIG. 6is a schematic cross-sectional view of a semiconductor device package6in accordance with some embodiments of the present disclosure. As shown inFIG. 6, in contrast to the semiconductor device package5, the first thermal conductive section22of the semiconductor device package6may include one or more first portions221and one or more second portions222connected to each other by one or more connection portions223. The first portion221, the second portion222and the connection portion223may be disposed substantially at the same level, forming a lid. The material of the connection portion223is different from that of the first portion221and the second portion222. In some embodiments, the material of the connection portion223may include a thermal interface material, an adhesive material or an insulation material such as rubber. In some embodiments, the connection portion223may include a hollow space connected to pipe(s). The hollow space may be in communication with an extra heat dissipation structure through the pipe(s) such that cooling medium can be circulated around the semiconductor die10. By way of examples, an air cooling structure or a water cooling structure can be connected to the connection portion223such that air or water can be circulated around the semiconductor die10to increase heat dissipation effect. Meanwhile, the anisotropic thermal conductive structure20can still provide heat dissipation.

FIG. 7is a schematic cross-sectional view of a semiconductor device package7in accordance with some embodiments of the present disclosure. As shown inFIG. 7, the anisotropic thermal conductive structure20of the semiconductor device package6may further include a top thermal conductive section29disposed on the first thermal conductive section22. In some embodiments, the top thermal conductive section29may include a plurality of fin structures29F. The fin structures29may be exposed to the environment. The film stacks of the top thermal conductive section29may be stacked substantially in the lateral direction Dx or substantially in the vertical direction Dz. The fin structures29F can increase an outer area of the top thermal conductive section29, and thus enhance heat dissipation effect. The top thermal conductive section29can be integrated into any of the semiconductor device packages in the afore-mentioned embodiments of the present disclosure.

FIG. 8is a schematic perspective view of a semiconductor electronic device package8in accordance with some embodiments of the present disclosure,FIG. 8Ais a schematic cross-sectional view of a semiconductor device package8taken in a line C-C′ inFIG. 8, andFIG. 8Bis a schematic cross-sectional view of a semiconductor device package8taken in a line D-D′ inFIG. 8. As shown inFIG. 8,FIG. 8AandFIG. 8B, the semiconductor device package8includes a lead frame70, a semiconductor die80and an encapsulant82. The lead frame70includes a die pad72, a plurality of supporting bars74extending from the die pad72, and a plurality of fingers76spaced apart the die pad72. The material of the lead frame70may be the same as that of the anisotropic thermal conductive structure20as described in the above descriptions. For example, the lead frame70may include at least two pairs of film stacks, and each pair of the film stacks of the lead frame70may include a metal film and a nano-structural film alternately stacked as illustrated inFIG. 1B. The semiconductor die80is disposed on the die pad72by a thermal interface material81such as a die attach film (DAF), and electrically connected to the fingers76through bond wires84, for example. The encapsulant82encapsulates the lead frame70and the semiconductor die80. The encapsulant82may include a molding compound. In some embodiments, the film stacks of the lead frame70are stacked substantially in the vertical direction Dz, and thus a thermal conductivity of the lead frame70substantially in a lateral direction Dx or Dy is larger than that of the lead frame70substantially in the vertical direction Dz. Accordingly, heat generated by the semiconductor die80can be efficiently transferred from the die pad72to the supporting bars74.

FIG. 9A,FIG. 9B,FIG. 9C,FIG. 9D,FIG. 9E,FIG. 9FandFIG. 9Gillustrate operations of manufacturing a semiconductor electronic device package in accordance with some embodiments of the present disclosure. As shown inFIG. 9A, a metal film20A such as a copper foil is provided. The metal film20A can be formed by sputtering or any suitable techniques. The metal film20A may be shaped to predetermined shape and size. As shown inFIG. 9B, a nano-structural film20B such as a graphene film is formed on the metal film20A to form a pair20P of film stacks. In some embodiments, the nano-structural film20B can be formed by chemical vapor deposition (CVD) or any suitable techniques. As shown inFIG. 9C, a plurality of pairs20P are laminated on each other with the nano-structural films20B facing down. In some embodiments, the two sides of the metal film20A of the upmost pair20P are both covered by the nano-structural films20B. As shown inFIG. 9D, the pairs20P of film stacks are pressed, for example by hot plates90to make the pairs20P of film stacks connected firmly to one another, forming a multi-layered stacking structure100. The multi-layered stacking structure100may be used to form the anisotropic thermal conductive structures or lead frames as described in the present disclosure.

In some embodiments, the multi-layered stacking structure100can be stamped or forged by a tool92such as stamping die or forging die as shown inFIG. 9Eto form the anisotropic thermal conductive structure20as illustrated inFIG. 1Aor the lead frame70as illustrated inFIG. 8.

In some other embodiments, the multi-layered stacking structure100can be rotated by 90 degrees, and cut into a plurality of slices100S as shown inFIG. 9F. The slice100S of the multi-layered stacking structure100can be further pressed or grinded to reduce its thickness. The slices100S can be used to form any sections of the anisotropic thermal conductive structure with laterally stacking films. By way of examples, the slice100S can be used to form the second thermal conductive section24inFIG. 2; the first thermal conductive section22and the second thermal conductive section24inFIG. 3; the first thermal conductive section22and the third thermal conductive section26inFIG. 4; the first thermal conductive section22and the third thermal conductive section26inFIG. 5A; the first portion221and the second portion222of the first thermal conductive section22and the third thermal conductive section26inFIG. 6; and the first thermal conductive section22and the second thermal conductive section24inFIG. 7.

In some embodiments, the slice100S of the multi-layered stacking structure100can be processed by a milling tool94as shown inFIG. 9Gto form the top thermal conductive section29as shown inFIG. 7.

In some embodiments of the present disclosure, the anisotropic thermal conductive structure have anisotropic thermal conductive characteristic that helps transfer heat from the semiconductor die in a more efficient way with less thermal resistance, and thus heat dissipation of the semiconductor device package can be improved.

As used herein, the singular terms “a,” “an,” and “the” may include a plurality of referents unless the context clearly dictates otherwise.