This application claims priority, under 35 U.S.C § 119, from Korean Patent Application No. 10-2010-0114550 filed Nov. 17, 2010, the entirety of which is incorporated by reference herein.
1. Field
Exemplary embodiments relate to a semiconductor package and a method of fabricating the semiconductor package.
2. Discussion of the Related Art
With trends toward small, slim and dense electronic products, small and slim printed circuit boards are required. Together with portability of electronic devices, multi-function and mass data transmitting and receiving functions may necessitate complicated printed circuit board designs. As a result, there has been an increased need for multi-layer printed circuit boards where power supply circuits, ground circuits, signal circuits, etc. are formed.
Semiconductor chips, such as central processing units, power integrated circuits, and the like may be mounted on multi-layer printed circuit boards. Such semiconductor chips may generate high temperature when in use. The high temperature may cause malfunctions of the semiconductor chips due to overload.
When a plurality of semiconductor chips are mounted on a printed circuit board, electromagnetic interference (EMI) may be generated between the semiconductor chips. Such EMI may cause malfunctions of the semiconductor chips.
According to an embodiment of the inventive concept , a semiconductor package comprises a package substrate including a package cap interconnection through via at opposite edges of the package substrate, a first semiconductor chip stacked on the package substrate, at least one second semiconductor chip stacked on the first semiconductor chip and having a width narrower than a width of the first semiconductor chip, a molding film covering an upper surface of the first semiconductor chip adjacent to a lateral surface of the second semiconductor chip, and covering a lateral surface of the second semiconductor chip, a thermal interface film disposed on the second semiconductor chip, a package cap in contact with the thermal interface material film and covering the first and second semiconductor chips, and a package adhesion pattern between the package cap interconnection through via and a lower part of the package cap.
In an exemplary embodiment, an upper surface of the molding film is positioned at the same height as an upper surface of the second semiconductor chip and the thermal interface film is extended from on top of the second semiconductor chip to on top of the molding film, and is between the molding film and the package cap.
In another exemplary embodiment, an upper surface of the molding film is higher than an upper surface of the second semiconductor chip.
The package substrate further comprises a package ground layer, the package cap interconnection through via being in contact with the package ground layer. Alternatively, the package cap interconnection through via is not in contact with the package ground layer.
The package cap interconnection through via is formed of a conductive film. Alternatively, the package cap interconnection through via is formed of an insulation film.
The package adhesion pattern is conductive.
The package cap includes a portion (e.g., a pin portion) protruding upward from the package cap.
In an exemplary embodiment, the package substrate further comprises conductive layers and a plurality of insulation films being stacked in a multi-layer structure, and the package cap interconnection through via includes a plurality of sub through vias penetrating the insulation films and disposed at different layers from each other. In this case, adjacent sub through vias in the vertical direction are not aligned with (i.e., offset from) each other.
The package substrate further comprises a power layer, the package cap interconnection through via not being with the power layer.
The molding film is formed of thermal epoxy.
The thermal interface film is formed of thermal grease, epoxy material, or metallic solid particles included in an epoxy material.
According to embodiments of the inventive concept, a method of manufacturing a semiconductor package comprises preparing a wafer including a plurality of first semiconductor chips, mounting a plurality of second semiconductor chips on the wafer including the plurality of first semiconductor chips, each of the plurality of second semiconductor chips respectively overlapping a first semiconductor chip of the plurality of first semiconductor chips, forming a molding film covering the second semiconductor chips, removing part of the molding film to expose upper surfaces of the second semiconductor chips, separating the wafer into unit portions having a second semiconductor chip stacked on a first semiconductor chip, mounting the first semiconductor chip of a unit portion on a package substrate, and covering the first and second semiconductor chips of the unit portion with a package cap, wherein a thermal interface film is positioned between the package cap and the second semiconductor chip of the unit portion.
The covering the first and second semiconductor chips by the package cap includes fixing the package cap with an adhesion pattern positioned between the package cap and the package substrate.
The forming a molding film covering a lateral surface of the second semiconductor chip an exposing an upper surface of the second semiconductor chip includes forming a molding film covering lateral and upper surfaces of the second semiconductor chip, and exposing the upper surface of the second semiconductor chip by grinding the molding film.
The method further comprises forming the thermal interface material film before separating the wafer.
According to an embodiment of the inventive concept, a semiconductor package comprises a package substrate including a through via, a first semiconductor chip stacked on the package substrate, at least one second semiconductor chip stacked on the first semiconductor chip and having a width narrower than a width of the first semiconductor chip, a molding film on a portion of an upper surface of the first semiconductor chip adjacent to a lateral surface of the second semiconductor chip, a thermal interface film disposed on the second semiconductor chip, a package cap in contact with the thermal interface film and positioned over the first and second semiconductor chips, and a conductive package adhesion pattern between the through via and a part of the package cap.
Embodiments of the present inventive concept will become apparent from the following description with reference to the following figures, wherein like reference numerals may refer to like parts throughout the various figure, and wherein
The inventive concept is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Like numbers may refer to like elements throughout.
As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that when an element or layer is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another element or layer, it can be directly on, connected, coupled, or adjacent to the other element or layer, or intervening elements or layers may be present.
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According to an embodiment, the package substrate 200 is a multi-layer printed circuit board. The package substrate 200 includes a plurality of insulation films 202. First signal patterns 204s, 204c, and 204d are disposed on an insulation film placed at the lowermost layer among the insulation films 202. According to an embodiment, the first signal patterns 204s, 204c, and 204d include a first package cap interconnection signal pattern 204s, a first chip ground voltage signal pattern 204c, and a first power supply voltage signal pattern 204d. Second signal patterns 212s, 212c, and 212d are disposed on an insulation film placed at the uppermost layer among the insulation films 202. The second signal patterns 212s, 212c, and 212d include a second package cap interconnection signal pattern 212s, a second chip ground voltage signal pattern 212c, and a second power supply voltage signal pattern 212d. According to an embodiment, a package power layer 206 and a package ground layer 210 are disposed in insulation films 202 located at different layers from each other. Third signal patterns 208 are also disposed in one or more insulation films 202. The first signal patterns 204s, 204c, and 204d, the second signal patterns 212s, 212c, and 212d, the package power layer 206, the third signal patterns 208, and the package ground layer 210 are formed of a conductive film. The package substrate 200 includes a plurality of package substrate through vias 220s, 220c, and 220d which penetrate the insulation films 202. The package substrate through vias 220s, 220c, and 220d include a package cap interconnection through via 220s, a chip ground voltage through via 220c, and a power supply voltage through via 220d. The package cap interconnection through via 220s is disposed adjacent to an edge of the package substrate 200.
The package cap interconnection through via 220s connects the first package cap interconnection signal pattern 204s and the second package cap interconnection signal pattern 212s without being connected to the package power layer 206 and the package ground layer 210. The chip ground voltage through via 220c connects the first chip ground voltage signal pattern 204c and the second chip ground voltage signal pattern 212c and is connected with the package ground layer 210. The power supply voltage through via 220d connects the first power supply voltage signal pattern 204d and the second power supply voltage signal pattern 212d and is connected to the package power layer 206.
Outer solder balls 230s, 230c, and 230d are attached at lower parts of the first signal patterns 204s, 204c, and 204d, respectively. The outer solder balls 230s, 230c, and 230d include a package cap interconnection outer solder ball 230s, a chip ground voltage outer solder ball 230c, and a power supply voltage outer solder ball 230d.
A width of the second semiconductor chip 120 is less than that of the first semiconductor chip 100. For example, according to an embodiment, the first semiconductor chip 100 is a logic chip, and the second semiconductor chip 120 is a memory chip. The first semiconductor chip 100 includes a semiconductor substrate 1, a chip through via 5 penetrating the semiconductor substrate 1, and a chip ball land 13 electrically connected with the chip through via 5. According to an embodiment, the first semiconductor chip 100 is mounted on the package substrate 200 in a flip chip bonding manner. The second semiconductor chip 120 is mounted on the first semiconductor chip 100 in the flip chip bonding manner. The chip ball land 13 of the first semiconductor chip 100 is electrically connected with the second signal patterns 212c and 212d by first inner solder balls 19. The first and second semiconductor chips 100 and 120 are electrically connected to each other by second inner solder balls 124. A dam 140 is disposed adjacent to an edge of the package substrate 200. A space between and around the second inner solder balls 124 is filled by a first underfill resin film 126. A space between and around the first inner solder balls 19 is filled by a second underfill resin film 142.
A molding film 131 is positioned to cover part of an upper surface of the first semiconductor chip 100 and a lateral surface of the second semiconductor chip 120. According to an embodiment, the upper surface of the second semiconductor chip 120 may be level in height with the upper surface of the molding film 131. The molding film 131 is formed of, for example, an epoxy resin series.
In an exemplary embodiment, a thermal interface film 132 is interposed between the package cap 300 and the second semiconductor chip 120 and between the package cap 300 and the molding film 131. The thermal interface film 132 includes, for example, thermal grease, epoxy material, or metallic solid particles such as indium mixed with the thermal grease and epoxy material. The thermal interface film 132 maintains a solid state at a low temperature and is changed into a liquid state at a high temperature. According to an embodiment, the thermal interface film 132 has an adhesive function and/or is conductive.
According to an embodiment, the package cap 300 is formed of a metallic material. A package adhesion pattern 310 is positioned between a lower part of the package cap 300 and an edge of the package substrate 200. The package adhesion pattern 310 is used to adhere and fix the package cap 300 to the package substrate 200. In an exemplary embodiment, the package adhesion pattern 310 is conductive. According to an embodiment, the package adhesion pattern 310 is adjacent to the second package cap interconnection signal pattern 212s. Further, according to an embodiment, the package adhesion pattern 310 overlaps the package cap interconnection through vias 220s. According to an embodiment, since the package cap 300 is fixed to the package substrate 200 and the package adhesion pattern 310 positioned on the package substrate 200 is connected thermally and electrically to the package substrate 200, it is not necessary to form holes for shield cans or thermal sink plates at a package substrate, a module substrate, or a mother board. Accordingly, not required to alter the designs for package, module, or mother substrates by forming the holes.
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According to an embodiment, the molding film 131 is formed of an epoxy series material, which has the thermal conductivity of about 0.30 W/(m·K) to about 7 W/(m·K). For example, in the case that the molding film 131 is formed of a thermal epoxy, its thermal conductivity is about 1 W/(m·K) to about 7 W/(m·K), which is higher than 0.025 W/(m·K) the thermal conductivity of air. Accordingly, if the molding film 131 is located between the thermal interface material film 132 and the first semiconductor chip 100, it is possible to discharge the heat more effectively as compared to the situation when air instead of the molding film 131 is located between the thermal interface material film 132 and the first semiconductor chip 100. That is, it is possible to increase the discharge of heat produced by the first semiconductor chip 100 by positioning the molding film 131 between the thermal interface material film 132 and the first semiconductor chip 100. In a case where the molding film 131 is formed of thermal epoxy, for example, a heat spreading or heat sinking effect may be improved.
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In some embodiments, the package cap interconnection through via 220s is formed of an insulation film. According to the present embodiment, the package cap 300 performs a heat spreading function.
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In an exemplary embodiment, the molding film 130 covers lateral sides of the second semiconductor chips 120 and the upper surfaces of the second semiconductor chips 120 are exposed.
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In an exemplary embodiment, the package cap 300 prevents the package substrate 200 from being warped or twisted. The semiconductor package 500 has radiation and electromagnetic wave shield functions. This means that processes for electromagnetic wave shielding and radiation are not needed at a semiconductor module level or a mother board level. Accordingly, it is possible to simplify a following assembly process.
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According to an embodiment, the module substrate 530 is a multi-layer printed circuit board which includes a first module ground layer 540, a second module ground layer 542, and a module power layer 544 embedded therein. The first module ground layer 540 is electrically connected with a package cap 300 and is supplied with a cap ground voltage VSS
In an exemplary embodiment, the module cap 510 and the package cap 300 share a common electrical connection to the first module ground layer 540. Alternatively, the module cap 510 and the package cap 300 are electrically connected with different layers independently. According to an embodiment, ground voltages are applied to the module cap 510 and the package cap 300 through different paths.
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A semiconductor package according to an exemplary embodiment of the inventive concept can be applied to a semiconductor module. This is more fully described with reference to
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The semiconductor package 500 may be identical to that illustrated in
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The semiconductor package 501 may be identical to that illustrated in
The above-describe package technology may be applied to an electronic device (or, an electronic system).
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According to an embodiment, the electronic device 1300 further includes an interface 1340 which is configured to transmit and/or receive data to or from a communication network. The interface 1340 may be formed to operate in wired and wireless manners. For example, the interface 1340 includes an antenna and/or a wired/wireless transceiver. Although not shown in
The electronic device 1300 may be implemented by a mobile system, a personal computer, an industrial personal computer, or a logic system executing various functions. For example, the mobile system may be a personal digital assistant, a portable computer, a web tablet, a mobile phone, a wireless phone, a laptop computer, a memory card, a digital music system, and/or an information sending/receiving system. In the event that the electronic device 1300 executes wireless communications, it may use a communication interface protocol which is applied to a 3G communication system such as CDMA, GSM, NADC, E-TDMA, WCDMA, and CDMA200, or other communication system.
A semiconductor package according to an exemplary embodiment of the inventive concept includes a package cap which is capable of radiating high temperatures and performs a shield function for preventing transmission of electromagnetic waves. This enables chip malfunctions to be prevented and the reliability of the devices to be improved. The package cap also prevents a package substrate from being warped or twisted. Due to the semiconductor package radiation and electromagnetic wave shield functions, processes for electromagnetic wave shielding and radiation are not needed at a semiconductor module level or a mother board level. Accordingly, it is possible to simplify a following assembly process.
A semiconductor package according to an exemplary embodiment includes a package cap which is fixed and connected to a package substrate by an adhesion pattern disposed on the package substrate. Accordingly, it is unnecessary to form holes for shield cans or thermal sink plates at a package substrate, a module substrate, or a mother board. As a result, it is unnecessary to alter the designs for package, module, or mother substrates to allow for heat radiation and shielding of electromagnetic waves.
In a semiconductor package according to another embodiment of the inventive concept, a width of a second semiconductor chip stacked on a first semiconductor chip is narrower than that of the first semiconductor chip, and the first and second semiconductor chips are covered by a package cap. A mold film is interposed between the first semiconductor chip and the package cap. As compared with the case that the mold film is not interposed between the first semiconductor chip and the package cap (e.g., only air is between the first semiconductor chip and the package cap), the mold film has a higher thermal conductivity than air, so that it is possible to more effectively radiate the heat produced by the lowermost semiconductor chip in a stacked semiconductor chip structure.
With a semiconductor package according to still another embodiment of the inventive concept, a thermal interface film is disposed between a second semiconductor chip and a package cap, and an upper surface of a molding film is higher than that of a second semiconductor chip. The thermal interface film is changed into a liquid state at a high temperature during a package making process. Since the upper surface of the molding film is higher than that of the second semiconductor chip, the molding film contains the thermal interface film in the liquid state.
With a semiconductor package according to still another embodiment of the inventive concept, a package substrate including embedded semiconductor chips may include a package cap interconnection through via and an embedded ground layer. The package cap interconnection through via is not connected with the ground layer. That is, the package cap may be grounded through a path different from that of the semiconductor chips. In this case, it is possible to reduce the ESD noise more effectively.
In some embodiments, the package cap interconnection through via is connected with the ground layer. That is, the package cap is grounded via the same path as the semiconductor chips. In this case, it is possible to reduce the EMI more effectively.
Although the present inventive concept has been described in connection with the embodiments of the present inventive concept illustrated in the accompanying drawings, it is not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and changes may be made thereto without departing from the scope and spirit of the inventive concept.
Number | Date | Country | Kind |
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10-2010-0114550 | Nov 2010 | KR | national |