Induction Heating Soldering Apparatus For Semiconductor Package With Embedded Thermal Conductive Member

Abstract

The present invention relates to a heat dissipation semiconductor package with an embedded heat-conducting member and a method for manufacturing the same. The heat-conducting member, which is a heat dissipation means for releasing heat generated inside the semiconductor package to the outside, is embedded in the molding part forming the outer shape of the semiconductor package, thereby enabling optimal heat conduction within the minimum thickness of the molding part of the semiconductor package.

Description

Technology Field

[0001] The present invention relates to a semiconductor package, and more particularly to a semiconductor package including a heat dissipation technology through a thermal conductive member and the manufacture thereof. Background Technology

[0003] A semiconductor package is formed by mounting a semiconductor chip on a substrate and molding a single module, in which the semiconductor chip and lead frame are connected via bonding flip-chips or bonding wires, using a thermosetting material such as EMC (Epoxy Molding Compound) to create a package body (molding portion).

[0004] As illustrated in Fig. 8, semiconductor packages are manufactured through eight major processes. First, the wafer, which serves as the substrate for the integrated circuit, uses very high-purity single-crystal silicon (SiO2). It is produced as an ingot, cut, and used as a wafer. On this wafer, an oxidation process is followed by a photolithography process (photosensitization, exposure, and development), and then an etching process. Subsequently, circuit patterns are implemented through thin film deposition and metal wiring processes. Depending on the stacking structure, these processes are repeated to implement multilayer circuits. Afterward, an EDS process is performed to verify whether individual semiconductor chips have reached the desired quality level through electrical characteristic testing. If a certain quality is achieved through the EDS process, a packaging process is conducted in which epoxy resin is extruded and cured onto the semiconductor chips to create pathways for the chips to exchange signals with the outside and to protect them from various external environments.

[0005] At this stage, the final product created through the packaging process is called a semiconductor package.

[0006] Early semiconductor packages were called SSI (small-scale integration), which were small-scale integrated circuits containing only a few transistors. This evolved into MSI (Middle Scale Integration), which included hundreds of transistors, and then into LSI (Large Scale Integration), which included tens of thousands of transistors. Currently, it is evolving into VLSI (Very Large Scale Integration), a form of large-scale semiconductor chip containing 10,000 to 1,000,000 transistors.

[0007] Reflecting the increasing complexity that has continued since then, Ultra-Large-Scale Integration (ULSI) is being developed and manufactured, including semiconductor chips with ultra-large integration density containing over a million transistors and integrated circuits that include all components required for computers or other systems, such as System-On-a-Chip (SOC), on a single chip.

[0008] As such, as semiconductor technology advances and the speed and functionality of semiconductor chips increase, the problem of heat generation is becoming increasingly serious, making the thermal dissipation of semiconductor packages extremely important.

[0009] Conventional heat dissipation technology for semiconductor packages widely utilizes a technique of directly attaching a heat sink to the surface of the package body (hereinafter referred to as the molding part). In semiconductor packages according to this conventional technology, heat generated from the semiconductor chip is transferred to the heat sink through the plastic molding part and released to the outside.

[0010] However, the plastic material constituting the molding part not only has low thermal conductivity, but due to the thickness of the molding part itself, heat dissipation through the heat sink attached to the molding part is also limited.

[0011] Another heat dissipation technology for semiconductor packages involves attaching a sheet (TIM sheet) containing a thermal interface material (TIM) to the molding part, as shown in Fig. 1. However, since this TIM sheet is also attached to the surface of the molding part, heat dissipation is still not significant. Furthermore, the TIM sheet is attached to the molding part through self-adhesion or an adhesive, but after a long period of time, it easily detaches from the molding part due to weakened adhesion, which leads to a problem of reduced thermal conductivity. Prior art literature

[0013] Korean Published Patent No. 10-2021-0143224 Korean Published Patent No. 10-2021-0096497 The problem to be solved

[0014] The present invention was devised to solve the problems of the aforementioned prior art, and aims to provide a semiconductor package and a method for manufacturing the same that can achieve improved performance of the semiconductor chip by preventing malfunction and damage to the semiconductor chip caused by overheating through a heat dissipation structure of the semiconductor package to effectively dissipate heat generated from the semiconductor chip. means of solving the problem

[0016] A heat dissipation semiconductor package according to the present invention for solving the above-mentioned problem comprises a substrate, a semiconductor chip mounted on the substrate, a molding portion surrounding the side of the semiconductor chip on the substrate, and a heat-conducting member embedded in the molding portion to release heat generated from the semiconductor chip to the outside of the molding portion.

[0017] Here, an intaglio portion is formed with a certain thickness on at least one side of the molding portion, and the heat-conducting member includes a heat-conducting sheet bonded inside the intaglio portion to release heat generated from the semiconductor chip to the outside.

[0018] And, a surface with a plurality of irregularities is formed on the bottom surface of the aforementioned engraved portion, and the heat conductive member further comprises a metal layer deposited on the surface with the irregularities and a solder paste applied on the metal layer, so that the heat conductive sheet is soldered to the metal layer.

[0019] In addition, the method for manufacturing a heat dissipation semiconductor package according to the present invention for solving the above-mentioned problem comprises: providing a semiconductor package in which the packaging process of a conductor chip is completed; forming an intaglio portion having an uneven surface formed by laser processing on at least one surface of a molding portion forming the outer shape of the semiconductor package; depositing a metal layer by plating on the uneven surface; dispensing solder paste on the metal layer; mounting a heat conductive sheet on the solder paste; and heating the solder paste to melt the solder paste.

[0020] Meanwhile, an induction heating soldering device for inductively heating a metal layer deposited on the surface of a molding portion of a heat dissipation semiconductor package according to the present invention and soldering a heat-conducting sheet to the metal layer comprises: an induction heating coil electrically connected to a high-frequency power supply unit to induce electromagnetic waves; a magnetic core located inside the induction heating coil to concentrate magnetic flux to the heat-conducting sheet; and a coil bobbin in which the induction heating coil is disposed on an outer surface and the magnetic core is installed in the center, wherein the upper part of the coil bobbin is open so that cooling air flows into the coil bobbin through the upper opening, and a plurality of through-holes are formed on the side of the coil bobbin so that the cooling air can be discharged to the outside through the through-holes after passing through the magnetic core. Effects of the invention

[0022] The heat dissipation semiconductor package with an embedded heat-conducting member of the present invention configured as described above and the method for manufacturing the same have the following advantages.

[0023] First, since the thermal conductive member that dissipates heat generated inside the semiconductor package to the outside is embedded within the thickness of the molding portion forming the outer shape of the semiconductor package, there is an advantage in that optimal thermal conduction can be achieved within the minimum thickness of the molding portion of the semiconductor package.

[0024] Second, it has the advantage of enabling high capacity, miniaturization, and high reliability by efficiently dissipating heat within the semiconductor package without the need for additional external heat dissipation components.

[0025] Third, as the thermal conductive member is embedded in the surface of the molding part, the thermal conductive member can also be installed on the upper surface and / or side of the molding part, thereby enabling three-dimensional heat dissipation and heat conduction, and there is an advantage of being able to actively respond to the heat dissipation area according to the spatial environment where the semiconductor package is installed.

[0026] Fourth, by directly implementing a thermal conductive member in a semiconductor package after the semiconductor packaging process, it is possible to design a layout for a continuous process (in-line process) after the packaging process, which has a significant advantage for mass production.

[0027] Fifth, since the heat-conducting member is implemented as a porous indentation (irregular surface) on the surface of the molding part, the heat dissipation surface area is greatly expanded, which has the advantage of allowing a large amount of heat to be rapidly discharged.

[0028] Sixth, it is capable of universally supporting various semiconductor package implementation methods such as wire bonding, ply-chip bonding, and TSV (Through Silicon Via), and also has the advantage of enhancing heat dissipation performance in fan-out wafer-level packages, which will be the main package type in the future. Brief explanation of the drawing

[0030] Figure 1 is a photograph showing the state in which a conventional TIM sheet is attached to a semiconductor package. FIG. 2 is a schematic cross-sectional view of a heat dissipation semiconductor package according to an embodiment of the present invention. FIG. 3 is a photograph of an actual product in which a thermal conductive member is directly implemented in a heat dissipation semiconductor package according to an embodiment of the present invention. FIG. 4 is a figure illustrating an example of a usage state of a heat dissipation semiconductor package according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating the process sequence for manufacturing a heat dissipation semiconductor package according to an embodiment of the present invention. FIGS. 6a to 6c are conceptual diagrams illustrating the process sequence for manufacturing a heat dissipation semiconductor package according to an embodiment of the present invention. FIG. 7 is a figure showing the process sequence for manufacturing a heat dissipation semiconductor package according to an embodiment of the present invention as an actual product. FIG. 8 is a conceptual diagram illustrating that the eight major processes for manufacturing a conventional semiconductor package and the process for manufacturing a heat dissipation semiconductor package according to an embodiment of the present invention are implemented as a continuous in-line process. FIG. 9 is a conceptual diagram illustrating a side cooling air discharge type in an induction heating unit applied to a heat dissipation semiconductor package according to an embodiment of the present invention. FIG. 10 is a conceptual diagram illustrating an upper cooling air discharge type in an induction heating unit applied to a heat dissipation semiconductor package according to an embodiment of the present invention. Specific details for implementing the invention

[0031] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0033] The core technical concept of the present invention is that a heat dissipation means (hereinafter referred to as a heat-conducting member) for releasing heat generated inside a semiconductor package to the outside is embedded in a molding part forming the outer shape of the semiconductor package, thereby providing the advantage of achieving optimal heat conduction within the minimum thickness of the molding part of the semiconductor package.

[0034] To this end, the present invention forms a recessed portion with a certain thickness in the molding portion of the most heat-generating area (hot spot: 'A' in FIG. 4) of a semiconductor package, deposits a metal layer on the recessed portion, and then bonds a thermal conductive sheet to the metal layer through a soldering process.

[0036] Hereinafter, an embodiment of a heat dissipation semiconductor package having an embedded heat-conducting member according to the present invention will be described in detail with reference to the attached drawings.

[0038] FIG. 2 is a schematic cross-sectional view of a heat dissipation semiconductor package according to an embodiment of the present invention, FIG. 3 is a photograph of an actual product in which a thermal conductive member is directly implemented in a heat dissipation semiconductor package according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating an example of the usage state of a semiconductor package according to an embodiment of the present invention.

[0040] Referring to FIGS. 2 and 3, a heat dissipation semiconductor package with an embedded heat-conducting member according to the present invention comprises a substrate (10), a semiconductor chip (20), a molding part (30), a heat-conducting member (40), and a solder ball (50), etc.

[0042] The above substrate (10) is, for example, a printed circuit board (PCB board). One or more semiconductor chips are mounted on one side of the substrate (10). Meanwhile, the other side of the substrate (10) (the side opposite to the one side) has a connection structure that can be connected to other PCB boards (for example, a motherboard: 80 in FIG. 4). Examples of connection structures include solder balls (50) and pin connectors.

[0043] However, the present invention is not limited to a substrate type. That is, a lead frame type may be applied instead of a substrate type. In other words, regarding the electrical connection method of the semiconductor chip, a method of connecting by attaching solder balls to a substrate is possible, and a method of connecting to a lead frame using wires is also possible.

[0045] The semiconductor chip (20) may be a semiconductor chip that performs various functions, such as memory, logic, a microprocessor, an analog device, a digital signal processor, or a System-on-Chip. Additionally, the semiconductor chip may be a multi-chip having a structure in which at least two semiconductor chips are stacked. For example, at least two semiconductor chips may all be of the same type of device, or one of the two semiconductor chips may be a memory device and the other may be a microcontroller device.

[0046] The semiconductor chip (20) illustrated in FIG. 2 is mounted on a substrate (10) by a flip-chip bonding method, but the mounting method of the semiconductor chip (20) is not limited thereto. For example, the semiconductor chip may be mounted on a substrate by a wire bonding method, or it may be mounted by a TSV (Through Silicon Via) method in which multiple semiconductor chips are stacked in a multi-layer and connected to each other through via holes.

[0047] As shown in FIG. 2, when a semiconductor chip (20) is mounted using a flip-chip bonding method, the semiconductor chip (20) can be connected to a substrate (10) through a bump (60). Meanwhile, configuration number '70', which is not described in FIG. 2, is a protective film for protecting the semiconductor chip. In this case, the protective film (70) has the form of an oxide film, a nitride film, or a film.

[0049] The molding part (30) above performs the function of sealing the semiconductor chip (20) to protect the semiconductor chip (20) from hazardous elements of the external environment. This molding part (30) may include an insulating material, such as a thermosetting resin like epoxy resin, a thermoplastic resin like polyimide, or a resin containing reinforcing materials such as inorganic fillers, specifically ABF, FR-4, BT resin, etc. Additionally, a molding material such as EMC (Epoxy molding compound) may be used in the molding part (30). Here, EMC is a thermosetting plastic with excellent mechanical, electrical insulation, and temperature resistance properties, and is a resin with a relatively small molecular weight capable of three-dimensional curing in the presence of a curing agent or catalyst. Of course, in the present invention, the material of the molding part (30) is not limited to the aforementioned materials.

[0050] In this way, the molding part (30) performs the roles of mechanical protection, electrical connection, and mechanical connection of the semiconductor chip (20). However, recently, as semiconductor technology has advanced, the speed of products has increased, and the number of functions has increased, the heat problem has become very serious, so technologies that effectively dissipate heat from the molding part (30) are being incorporated. That is, the molding part (30) protects the semiconductor chip (20) from external mechanical and chemical shocks by wrapping it with a package material such as EMC resin, and physically / electrically connects the semiconductor chip (20) to the system to supply power for the semiconductor chip (20) to operate, and enables the input and output of signals to perform desired functions, while also performing the role of dissipating heat generated during the operation of the semiconductor chip (20).

[0051] In the above-described aspect, the present invention implements a heat-conducting member (40: heat dissipation means) that releases heat generated from a semiconductor chip (20) to the outside of a semiconductor package in the molding part (30). That is, the heat-conducting member (40) is implemented within the thickness of the molding part (30). In the present invention, this is defined and used as a heat-conducting member embedded in the molding part (30).

[0053] Hereinafter, a heat-conducting member (40) embedded in a molding part (30) will be described in more detail with reference to FIGS. 2 to 4 and FIGS. 6a to 6b.

[0054] The above-described heat-conducting member (40) comprises a metal layer (41) formed on a molding part (30) and a heat-conducting sheet (42) bonded to the metal layer (41). To this end, on one side of the molding part (40), an indentation part (31) on which the metal layer (41) is deposited and an uneven surface (42) formed on the bottom surface of the indentation part (31) are formed.

[0056] The above-mentioned intaglio (31) can be formed to have a certain depth in at least one area of ​​the first surface of the molding portion. Such an intaglio (31) can be formed by removing the molding portion (30) to a certain depth through laser processing, etc., which will be described later. For example, as shown in FIG. 6a, the intaglio (31) can be formed by removing the remaining part and leaving only the molding portion with a thickness of 5 to 10 μm on the semiconductor chip (20) to protect the semiconductor chip (20) from the initial thickness of the molding portion (30). However, it is not limited to this, and the depth of the intaglio (31) can be varied depending on the type and size of the semiconductor package or semiconductor chip.

[0057] At this time, the engraved portion (31) may have the shape of a concave groove having a square plane inside while retaining an edge of a certain width on one side of the molding portion (30) as shown in FIG. 3(a), or it may have the shape of a concave groove extending radially from the center and vertex of each side of the square plane to the edge of the molding portion (30) as shown in FIG. 3(b). In the latter case, the area of ​​the heat-conducting member (40) can be maximized, which has the advantage of a superior heat dissipation effect.

[0059] As illustrated in FIGS. 6a and 6b, the uneven surface (32) may have an uneven shape in the form of diagonal or straight lines in which convex and concave patterns are periodically repeated on the bottom surface of the engraved portion (31) when the engraved portion (31) is formed through laser processing, etc. However, the present invention is not limited thereto and may have various shapes. This uneven surface (32) can increase the bonding strength with the metal layer (41) through anchoring of metal materials during the deposition process for forming the metal layer (41), and the heat dissipation surface area is expanded, thereby increasing the heat dissipation effect.

[0061] As illustrated in FIG. 6b, the metal layer (41) is formed on the uneven surface (32) inside the engraved portion (31), and serves to vertically transfer heat generated from the semiconductor chip (20), as well as to serve as a medium for soldering the heat-conducting sheet (42) to the molding portion (30) made of resin material. This metal layer (41) has a structure in which it is plated and deposited in the area processed as an engraved portion. To elaborate further, the metal layer (41) is formed inside the engraved portion (31) by a selective plating process, and can be carried out as dry or wet plating depending on laser processing and the semiconductor package state. A more detailed explanation of the process for forming the metal layer (41) will be provided later.

[0062] Here, the metal layer (41) may be composed of multiple layers. According to various embodiments, the metal layer may include a first metal layer (41a) and a second metal layer (41b). Here, the first metal layer (41a) is formed directly on the laser-processed engraved portion (31), and since it performs the role of having high bonding strength through anchoring to the molding portion (30) made of resin material and may also have an area in contact with the semiconductor chip (20), it is preferable to use a metal material with low diffusivity. For example, the first metal layer (41a) may include at least one of copper (Cu), nickel (Ni), aluminum (Al), titanium (Ti), and silicon (Si). And the second metal layer (41b) has excellent solderability for soldering with the thermal conductive sheet (420) and acts as a medium layer for thermal conductivity after bonding. Therefore, it is desirable to use a metal material with excellent solderability and good thermal conductivity for the second metal layer (41b). For example, the second metal layer (41b) may include at least one of copper (Cu), nickel (Ni), and gold (Au).

[0064] The above-mentioned heat-conducting sheet (42) is bonded onto the metal layer (41) in the form of a thin plate made of a heat-conducting material. More specifically, it is bonded onto the second metal layer (41b). This heat-conducting sheet (42) is placed at the outermost part of the engraved portion (31) in the molding portion (30) and serves to dissipate heat generated from the semiconductor chip (20) to the outside of the semiconductor package.

[0065] In addition, as shown in FIG. 4, when the heat dissipation semiconductor package of the present invention is assembled on the motherboard (70) of an electronic device, it can be connected to an additional heat dissipation means, such as a TIM sheet (300) and / or an EMI shielding member (400), to effectively release heat to the outside. Here, the TIM sheet (300) comprises a sheet made of a thermal interface material (TIM), and the EMI shielding member (400) is installed around the semiconductor package to block electromagnetic waves.

[0066] These heat-conducting sheets (42) may be made of metal materials such as copper or aluminum, metal materials such as silicon, or carbon-based fibers such as carbon or graphite. Of course, in the present invention, the material of the heat-conducting sheet is not limited to the aforementioned materials.

[0068] Referring to FIGS. 6b and 6c, the thermal conductive sheet (42) can be bonded to the metal layer (41) by soldering. To do this, solder paste (43) is applied between the thermal conductive sheet (42) and the metal layer (41).

[0069] Here, there are two main methods for performing soldering of the heat-conducting sheet (42) to the metal layer (41). One soldering method is a reflow soldering method, and the other is an induction heating soldering method.

[0070] However, when soldering is performed by the reflow soldering method, a material with high heat resistance must be used because the molding part must withstand high temperatures, and thermal damage may be caused to semiconductor chips, etc. contained within the semiconductor package during the soldering process. Therefore, in the present invention, it is more preferable to solder the heat-conducting sheet using an induction heating method rather than a reflow soldering method.

[0072] Meanwhile, since induction heating soldering locally heats only the conductors located within the magnetic field formed by the induction heating coil, there is no need to use materials with high heat resistance for the molding part, and it has the advantage of causing absolutely no thermal damage to semiconductor chips contained within semiconductor packages. The method of bonding the metal layer of the thermal conductive sheet through induction heating soldering will be explained in more detail later.

[0074] In the heat dissipation semiconductor package according to the present invention with the above-described configuration, heat generated from the semiconductor chip can be directly transferred to the metal layer and the heat conductive sheet through the recessed portion forming a minimum thickness in the molding portion and released into the air, and can also be released to the outside through another external heat dissipation member (TIM sheet or EMI shielding member).

[0076] As previously explained, the heat dissipation semiconductor package of the present invention forms a metallization (metal layer) on a molding portion that forms the outer shape of the semiconductor package (MID: Mold Interconnected Device), and a thermal conductive sheet is bonded to the metal layer by soldering. Accordingly, a thermal conductive member can be directly mounted in an embedded state inside a molding portion made of plastic material (MDM: Molding Direct Mounting).

[0077] As such, the heat dissipation semiconductor package according to the present invention can directly form a heat-conducting member by applying MID and MDM to the plastic molding part forming the outer shape, thereby enabling three-dimensional heat dissipation and heat conduction according to the three-dimensional shape of the semiconductor package, and thus has the advantage of being able to actively respond to the heat dissipation area according to the spatial environment in which the semiconductor package is installed.

[0079] Hereinafter, with reference to FIGS. 5 to 7, a method for manufacturing a heat dissipation semiconductor package in which a heat-conducting member is embedded according to an embodiment of the present invention will be described.

[0080] FIG. 5 is a flowchart illustrating the process sequence for manufacturing a heat dissipation semiconductor package according to an embodiment of the present invention, FIG. 6a to 6c are conceptual diagrams illustrating the process sequence for manufacturing a heat dissipation semiconductor package according to an embodiment of the present invention, and FIG. 7 is an actual product illustrating the process sequence for manufacturing a heat dissipation semiconductor package according to an embodiment of the present invention.

[0082] First, a semiconductor package in which the semiconductor packaging process is completed is provided (step S10 of FIG. 5, FIG. 6a), and a certain area is removed by laser processing on the upper surface of the molding part (30) forming the outer shape of the semiconductor package to form an intaglio part (31) (step S20 of FIG. 5, FIG. 6a, FIG. 7(a)). At this time, as the intaglio part (31) is formed by laser processing, a pattern groove in the form of fine irregularities is formed on the bottom surface forming the intaglio part (31). That is, an irregular surface (32) in the form of diagonal or straight lines in which convex and concave patterns are repeated periodically can be formed on the bottom surface of the intaglio part (31). A diode laser, a UV (ultraviolet) laser, an excimer laser, etc., may be used as the laser. In the present invention, forming the engraved portion is not limited to laser processing, and various methods such as CNC (computerized numerical control) milling, wet etching, and dry etching may be applied.

[0084] Subsequently, a metal layer (41) is deposited and formed by a plating metal in the area of ​​the aforementioned intaglio portion (31) (S30 in FIG. 5, FIG. 6b, FIG. 7(b)). Here, the metal layer (41) may be formed by stacking a first metal layer (41a) containing at least one of copper (Cu), nickel (Ni), aluminum (Al), titanium (Ti), and silicon (Si) on the uneven surface (32) forming the bottom surface of the intaglio portion (31), and a second metal layer (41b) containing at least one of copper (Cu), nickel (Ni), and gold (Au) on the first metal layer. Such a metal layer (30) can selectively achieve metallization on the area of ​​the intaglio portion using a wet plating method utilizing masking (100 in FIG. 6b), a dry thin film deposition method such as CVD (Physical Vapor Deposition), PVD (Chemical Vapor Deposition), or E-BEAM.

[0086] Next, a heat-conducting sheet (42) is soldered onto a metal layer (30) by an induction heating method and formed directly into the molding part. To do this, solder paste (43) is dispensed onto the metal layer (41) (S40 in FIG. 5, FIG. 6b, FIG. 7(c)). Then, the heat-conducting sheet (42) is mounted onto the solder paste (43) (S50 in FIG. 5, FIG. 6c). Subsequently, by placing an induction heating unit (200) on the heat-conducting sheet (42) and induction heating it (S60 and FIG. 5, FIG. 6C), the solder paste (43) is melted, thereby allowing the heat-conducting sheet (42) to be embedded in the molding part (30) in thickness (S70 and FIG. 5, FIG. 7(d)).

[0088] At this time, the induction heating unit (200) induction heats the metal layer (41). As a result, the solder paste (43) applied between the molding unit (30) and the heat conductive sheet (42) melts, allowing the heat conductive sheet (42) to be directly mounted on the engraved portion (31) of the molding unit (30) made of plastic material.

[0089] Here, the induction heating unit (200) comprises an induction heating coil (210) electrically connected to a high-frequency power supply unit (not shown) and a magnetic core (220) disposed inside the induction heating coil (210) to concentrate the magnetic flux induced by the induction heating coil (210) to the soldering area. At this time, although not shown, the induction heating unit (200) can be moved in the X-axis / Y-axis / Z-axis directions via a transfer robot (not shown) to continuously solder electronic components mounted on multiple circuit bricks. Additionally, the transfer robot (not shown) may be equipped with multiple induction heating units to simultaneously solder multiple semiconductor packages at once.

[0091] As described above, a thermal conductive sheet can be directly embedded into a molding part made of plastic injection molding using localized heating via magnetic induction. Consequently, compared to conventional reflow soldering methods, the molding part forming the outer shape of the semiconductor package can be used without restrictions on the material, and the thermal conductive sheet can be implemented in the molding part without causing thermal damage to components such as semiconductor chips mounted inside.

[0093] Meanwhile, as shown in FIG. 8, the heat dissipation semiconductor package according to the present invention has the advantage of being highly advantageous for mass production and production line construction because it can be implemented in-line in addition to the eight major manufacturing processes of a conventional semiconductor package by directly implementing a heat-conducting member in the molding part formed through the semiconductor packaging process.

[0095] In addition, the induction heating unit (200) used when manufacturing the heat dissipation semiconductor package of the present invention is provided with a cooling structure capable of cooling the heat of the magnetic core (220) to improve soldering quality.

[0096] FIG. 9 is a conceptual diagram illustrating a side cooling air discharge type in an induction heating unit applied to a heat dissipation semiconductor package according to an embodiment of the present invention.

[0097] Referring to FIG. 9, the induction heating unit (200) is configured to include an induction heating coil (210), a magnetic core (220), and a coil bobbin (230).

[0098] The above-mentioned induction heating coil (210) is electrically connected to a high-frequency power supply unit (not shown) to induce electromagnetic waves, and utilizes a hollow copper tube with high electrical conductivity. A cooling water channel is formed inside the hollow of the induction heating coil (210), and cooling water (235) is supplied. Therefore, heat generated from the magnetic core (220) can be rapidly discharged toward the induction heating coil (210). Here, the overall shape of the induction heating coil (210) can be implemented in various shapes such as helical, square, or circular. Furthermore, depending on the type of semiconductor package and the soldering environment, it may be in the form of a very thin wire (e.g., Litz wire) rather than a hollow tube.

[0099] The magnetic core (220) is located inside the induction heating coil (210) and serves to concentrate the magnetic induction generated from the induction heating coil (210). Here, the magnetic core (220) can be configured in various shapes, such as circular, square, or hollow.

[0100] The above coil bobbin (230) serves as a housing in which a magnetic core (220) is inserted inside and an induction heating coil (210) is placed on the outside. At this time, the coil bobbin (230) also serves as a pressing plate to prevent the heat conductive sheet (32) from lifting during soldering.

[0101] A spiral groove may be formed on the outer surface of the coil bobbin (230) so that the induction heating coil (210) can be stably fixed in place. Additionally, a plurality of through holes (231) serving as passages for cooling air are formed on the side of the coil bobbin (230) at regular intervals vertically. At this time, it is preferable to form a flow hole (234) having a relatively wide diameter on the inner surface of the coil bobbin (230) where the through holes (231) are formed, so that cooling air flowing in from the top of the coil bobbin (230) can flow smoothly into the through holes (231).

[0102] Meanwhile, the upper part of the coil bobbin (230) has an open structure to allow cooling air to flow in. Accordingly, the cooling air flowing into the upper part of the coil bobbin (230) passes through the magnetic core (220) and exits through the through-hole (231), thereby rapidly releasing the heat generated in the magnetic core (220) to the outside. At this time, for effective heat exchange with the cooling air, it is preferable to use a shape in which the interior is hollow with the entire upper and lower portions open, or a shape in which a hollow internal space can be maintained within the coil bobbin (230).

[0103] In this way, the induction heating unit (200) applied to the present invention cools the magnetic core (220) using cooling air, thereby preventing the magnetic core (220) from being heated to a high temperature and effectively focusing the magnetic flux of the induction heating coil (210), so that the soldering quality of the heat-conducting member within the semiconductor package is greatly improved.

[0105] Meanwhile, unlike Fig. 9, Fig. 10 applies an upper cooling air discharge type as the cooling structure of the induction heating part.

[0106] That is, a structure that is completely closed is applied rather than having a through-hole (231) formed on the side of the coil bobbin (230), and a partition wall (232) is formed in the open upper center of the coil bobbin (230). At this time, cooling air is injected on one side centered around the partition wall (232), and air that has completed heat exchange with the magnetic core (220) is discharged on the other side. To elaborate further, the air introduced on one side centered around the partition wall (232) passes through the magnetic core (220) inserted inside the coil bobbin (230), and then exits through the opening on the opposite side centered around the partition wall (232), thereby having a flow that releases the heat generated in the magnetic core (220) to the outside. At this time, on the inner surface of the bobbin coil (230) in contact with the magnetic core (220), a plurality of flow grooves (234) in the shape of inwardly recessed grooves are formed at regular intervals vertically. Accordingly, sufficient heat exchange with cooling air can be achieved not only on the inner side of the magnetic core (220) but also on the outer side of the magnetic core (220), thereby improving the cooling efficiency of the magnetic core.

[0107] Although each embodiment of the present invention has been described above with reference to the drawings, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention as described in the following claims.

[0109] In addition, the semiconductor package according to the present invention can be widely used in many industrial fields for all kinds of purposes, such as smartphones, tablets, wearables, digital cameras, wireless routers, etc. Explanation of the symbols

[0111] 10: Substrate 20: Semiconductor chip 30: Molding part 31: Engraving part 32: Uneven surface 40: Heat conduction member 41: Metal layer 42: Thermal conductive sheet 41a: First metal layer 41b: Second metal layer 43: Solder paste 50: Solder ball 60: Bump 70: Shield 80: Motherboard 200: Induction heating unit 210: Induction heating coil 220: Magnetic core 230: Coil bobbin 231: Through hole 232: Partition wall 233: Flow hole 234: Flow groove 235: Coolant

Claims

Claim 1 delete Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 An induction heating soldering device for soldering a heat-conducting sheet to a metal layer deposited on the surface of a molding portion of a semiconductor package by induction heating, comprising: an induction heating coil (210) electrically connected to a high-frequency power supply unit to induce electromagnetic waves; a magnetic core (220) located inside the induction heating coil (210) to concentrate magnetic flux to the heat-conducting sheet; and a coil bobbin (230) in which the induction heating coil (210) is positioned on an outer surface and the magnetic core (220) is installed in the center, wherein the upper part of the coil bobbin (230) is open so that cooling air flows into the coil bobbin (230) through the upper opening, and a plurality of through holes (231) are formed on the side of the coil bobbin (230) so that the cooling air passes through the magnetic core (220) and is discharged to the outside through the through holes (231).

Images