Semiconductor device and method for manufacturing semiconductor device

Abstract

Provided is a semiconductor device having excellent heat dissipation and electromagnetic wave suppression effects. To solve the above problem, the semiconductor device (1) of the present application is characterized by comprising: a semiconductor element (30); a conductive cooling member (40) provided on the upper portion of the semiconductor element (30); and a conductive heat-dissipating member (10) provided between the semiconductor element (30) and the cooling member (40) and containing a cured product of a resin, the conductive heat-dissipating member (10) being connected to a ground terminal (60) in a substrate (50) and electrically connecting the cooling member (40) and the ground terminal (60).

Description

Technical Field

[0001] The present invention relates to a semiconductor device and a method for manufacturing a semiconductor device, the semiconductor device being low in cost and easy to manufacture, and having excellent heat dissipation and electromagnetic wave suppression effects. Background Technology

[0002] In recent years, due to the trend of miniaturization of electronic devices, and on the other hand, the diversity of applications means that power consumption cannot change too much, heat dissipation measures within devices have become more important.

[0003] As heat dissipation measures in the aforementioned electronic devices, heat sinks, heat pipes, and heat fins made of metals with high thermal conductivity, such as copper and / or aluminum, are widely used. To achieve heat dissipation or mitigate internal temperatures, these highly thermally conductive heat dissipation components are positioned close to electronic components such as semiconductor packages, which are heat-generating parts within the electronic device. Furthermore, these highly thermally conductive heat dissipation components are positioned from the heat-generating electronic components down to lower temperature locations.

[0004] However, the heat-generating components within electronic devices are high-current-density semiconductor elements and other electronic components. "High current density" refers to a high electric or magnetic field strength that could become unwanted radiation. Therefore, if a heat sink made of metal is placed near these electronic components, it can absorb heat and also introduce high-order harmonic components of the electrical signals flowing within the components. Specifically, because the heat sink is made of metal, it can sometimes act as an antenna for high-order harmonic components or as a transmission path for high-order harmonic noise.

[0005] Therefore, it is hoped that a technology can be developed that balances heat dissipation and electromagnetic wave suppression.

[0006] For example, Patent Document 1 discloses a technology in which a semiconductor package with a cover is provided inside a shielding component with a large opening, and an annular cover contact portion is provided that is electrically in contact with the periphery of the upper surface of the cover, and the cover contact portion is electrically connected to the shielding component.

[0007] However, regarding the technology in Patent Document 1, although it achieves certain heat dissipation and electromagnetic wave suppression effects, it is believed that electromagnetic resonance may occur when the substrate and / or cooling components are large, thus failing to achieve sufficient electromagnetic wave suppression. Furthermore, further improvements are desired regarding heat dissipation.

[0008] Furthermore, in recent years, there has been a greater demand for improvements in manufacturing costs and / or ease of manufacturing, with a desire to develop semiconductor devices that can meet these requirements.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2012-164852 Summary of the Invention

[0012] Technical issues

[0013] The present invention was made in view of the following circumstances, and aims to provide a semiconductor device that can be manufactured at low cost and easily, and has excellent heat dissipation and electromagnetic wave suppression effects.

[0014] Technical solution

[0015] The inventors of this invention, through repeated research to solve the aforementioned problems, discovered that by forming a conductive and heat-conducting component between the semiconductor element and the conductive cooling component, efficient heat exchange can be achieved between the semiconductor element and the cooling component, and heat dissipation can be improved. Furthermore, by connecting the conductive and heat-conducting component disposed between the semiconductor element and the cooling component to a ground terminal in the substrate, and electrically connecting the cooling component to the ground terminal, an electrically enclosed space can be formed in the semiconductor device. As a result, even without additional electromagnetic wave shielding components such as sealing covers, the electromagnetic wave suppression effect can be significantly improved. Moreover, it was further discovered that by including a cured resin in the conductive and heat-conducting component, the conductive and heat-conducting component can be made flexible and deformable into various shapes, thereby achieving ease of manufacture and / or reduced manufacturing costs.

[0016] As a result, the semiconductor device of the present invention can achieve an unprecedented level of balance between heat dissipation and electromagnetic wave suppression. Furthermore, since the semiconductor device of the present invention does not have conductive shielding components such as the conductive sealing cover, it can also achieve thin-film semiconductor devices, reduce manufacturing costs, and improve manufacturing ease.

[0017] This invention is based on the above understanding, and its main points are as follows.

[0018] (1) A semiconductor device, characterized in that it comprises: a semiconductor element formed on a substrate; a conductive cooling member disposed on the upper part of the semiconductor element; a conductive thermally conductive member disposed between the semiconductor element and the cooling member, and containing a cured resin, wherein the conductive thermally conductive member is connected to a ground terminal in the substrate and electrically connects the cooling member to the ground terminal.

[0019] With the above-described structure, it can be manufactured at low cost and easily, and can achieve excellent heat dissipation and electromagnetic wave suppression effects.

[0020] (2) The semiconductor device described in (1) above, wherein the conductive and thermally conductive component is disposed in such a manner as to cover the semiconductor element and abuts against at least a portion of the upper surface and side surface of the semiconductor element.

[0021] (3) The semiconductor device described in (1) above, characterized in that the conductive and thermally conductive component encapsulates the upper surface and side surface of the semiconductor element.

[0022] (4) The semiconductor device according to any one of (1) to (3) above, characterized in that the resistivity of the conductive and thermally conductive component is 0.15 Ω·m or less.

[0023] (5) The semiconductor device according to any one of (1) to (4) above, characterized in that the resistivity of the conductive and thermally conductive component is 0.00001Ω·m or more.

[0024] (6) The semiconductor device according to any one of (1) to (5) above, characterized in that the conductive and thermally conductive component is magnetic.

[0025] (7) The semiconductor device according to any one of (1) to (6) above, characterized in that the conductive and thermally conductive component has adhesiveness or bonding on its surface.

[0026] (8) The semiconductor device according to any one of (1) to (7) above, characterized in that the conductive and thermally conductive component is flexible.

[0027] (9) The semiconductor device according to any one of (1) to (8) above, characterized in that the conductive and thermally conductive component contains a conductive filler.

[0028] (10) The semiconductor device described in (9) above, wherein the conductive filler is carbon fiber.

[0029] (11) The semiconductor device according to any one of (1) to (10) above, characterized in that the portion of the substrate other than the ground terminal is insulated.

[0030] (12) A method for manufacturing a semiconductor device, characterized in that it is a method for manufacturing a semiconductor device according to any one of (1) to (11) above, comprising:

[0031] The process of bonding the semiconductor element to the conductive and thermally conductive component by pressing a sheet-like conductive and thermally conductive component containing a cured resin onto the semiconductor element, and bonding the conductive and thermally conductive component to a ground terminal.

[0032] Based on the above configuration, it is possible to manufacture semiconductor devices with excellent heat dissipation and electromagnetic wave suppression effects at low cost and easily.

[0033] Technical effect

[0034] According to the present invention, a semiconductor device that can be easily manufactured at low cost and has excellent heat dissipation and electromagnetic wave suppression effects can be provided. Attached Figure Description

[0035] Figure 1 This is a diagram schematically showing the state of a cross-section of one embodiment of the semiconductor device of the present invention.

[0036] Figure 2 This is a diagram schematically showing the state of a cross-section of another embodiment of the semiconductor device of the present invention.

[0037] Figure 3 This is a diagram schematically showing the state of a cross-section of another embodiment of the semiconductor device of the present invention.

[0038] Figure 4 This is a perspective view schematically showing an assembled state of one embodiment of the semiconductor device of the present invention.

[0039] Figure 5 The diagram schematically illustrates a model of a semiconductor device used for analyzing the frequency characteristics in the embodiments, (a) showing the state observed from the surface side of the model of the semiconductor device, and (b) showing the state observed from the back side of the model of the semiconductor device.

[0040] Figure 6 This is a graph showing the electric field strength corresponding to the frequency in Embodiment 1 when the resistance value of the conductive and thermally conductive component of the semiconductor device in the Invention Example and the Comparative Example is changed.

[0041] Figure 7 This is a graph showing the electric field strength corresponding to the frequency in Example 2 when the magnetic properties of the conductive and thermally conductive components of the semiconductor device are changed.

[0042] Figure 8 (a) is a schematic diagram showing the state of a cross section of a conventional semiconductor device according to one embodiment, and (b) is a schematic diagram showing the state of a cross section of another conventional semiconductor device.

[0043] Symbol Explanation

[0044] 1. Semiconductor device

[0045] 10 Electrically and thermally conductive components

[0046] 20 Conductive Sealing Cover

[0047] 30 Semiconductor Components

[0048] 30a Side of semiconductor device

[0049] 30b Top surface of semiconductor device

[0050] 31 MSL

[0051] 40 Cooling components

[0052] 50 substrates

[0053] 51 Contact Block

[0054] 52 Conductive through-hole

[0055] 60 Grounding terminal

[0056] 100 Previous semiconductor devices

[0057] A electrically enclosed space

[0058] T refers to the thickness of the conductive thermal pad. Detailed Implementation

[0059] Hereinafter, an example of an embodiment of the present invention will be specifically described using the accompanying drawings.

[0060] Here, Figures 1-3 This is a schematic cross-sectional view illustrating an embodiment of the semiconductor device of the present invention. Additionally, Figure 4 This is a perspective view illustrating an embodiment of the semiconductor device of the present invention in an assembled state. It should be noted that, for ease of explanation, the shapes and / or dimensions of each component are shown in a manner different from the actual situation. The shapes and / or dimensions of each component can be appropriately varied for each semiconductor device, except as specified in this specification.

[0061] Semiconductor Devices

[0062] like Figures 1-3 As shown, the semiconductor device 1 of the present invention includes a semiconductor element 30, a conductive cooling member 40 disposed on the upper part of the semiconductor element 30, and a conductive heat-conducting member 10 disposed between the semiconductor element 30 and the cooling member 40 and containing a cured resin.

[0063] And, as Figures 1-3 As shown, in the semiconductor device 1 of the present invention, the conductive and heat-conducting component 10 is connected to the ground terminal 60 in the substrate 50, and the cooling component 40 is electrically connected to the ground terminal 60.

[0064] Although the semiconductor element 30 becomes a source of heat and electromagnetic waves, by placing a sheet component (conductive and thermally conductive component 10) with high conductivity and thermal conductivity between the semiconductor element 30 and the cooling component 40, heat conduction to the cooling component 40 is improved, resulting in excellent heat dissipation.

[0065] Furthermore, the semiconductor device 1 of the present invention contains a cured resin, and as... Figures 1-3 As shown, the cooling component 40 is connected to the ground terminal 60 in the substrate 50 via the conductive and thermally conductive component 10, and the ground terminal 60 is electrically connected to the cooling component 40 via the conductive and thermally conductive component 10, thus forming an electrically enclosed space within the semiconductor device 1 of the present invention. Figures 1-3 (The space enclosed by dashed lines) As a result, it can improve the electromagnetic wave blocking effect and also achieve excellent electromagnetic wave suppression effect.

[0066] Furthermore, in the semiconductor device 1 of the present invention, since there is no need to form an electromagnetic wave shielding component such as a sealing cover, it is possible to reduce manufacturing costs and improve manufacturing ease compared with conventional technologies that use electromagnetic wave shielding components.

[0067] It should be explained that Figure 8 (a) and (b) show examples of semiconductor devices based on prior art. Figure 8 In the semiconductor device 100 shown in (a), a high heat dissipation effect can be obtained because a conductive heat-conducting component 10 is provided to cover the semiconductor element 30. However, since there is no connection between the conductive heat-conducting component 10 and the ground terminal 60, it is not possible to form an electrically enclosed space within the semiconductor device 1, and thus a sufficient electromagnetic wave suppression effect cannot be obtained.

[0068] In addition, Figure 8 In the semiconductor device 100 shown in (b), because the conductive and heat-conducting components 10 are stacked in a manner that separates them from the sealing cover 20, the thermal resistance between the semiconductor element 30 and the cooling component 40 is greater than that between the semiconductor device 1 of the present invention, and thus sufficient heat dissipation cannot be obtained.

[0069] Next, the components constituting the semiconductor device of the present invention will be described.

[0070] (Semiconductor components)

[0071] like Figures 1-3 As shown, the semiconductor device 1 of the present invention includes a semiconductor element 30 formed on a substrate 50.

[0072] Here, the semiconductor element refers to any electronic component formed from semiconductors, without any particular limitation. Examples include integrated circuits such as ICs or LSIs, CPUs, MPUs, graphics processing units, and image sensors.

[0073] Regarding the substrate 50 for forming the semiconductor element 30, there are no particular limitations except for the provision of the ground terminal (GND) 60, and a suitable substrate can be used depending on the type of semiconductor device. The ground terminal 60 is formed on the back side.

[0074] It should be noted that, in Figure 1 and Figure 3 In the present invention, although the conductive and heat-conducting component 10 is directly connected to the ground terminal 60 exposed on the substrate 50, in the semiconductor device 1 of the present invention, for example, it is also possible to... Figure 2 As shown, contact blocks 51 are disposed circumferentially or partially around the semiconductor element 30 on the surface of the substrate 50. By connecting the contact blocks 51 to the conductive and thermally conductive member 10, the conductive and thermally conductive member 10 can be electrically connected to the ground terminal 60. The contact blocks 51 can be electrically connected to the ground terminal 60 via conductive through-holes 52 formed in the substrate 50, thereby electrically engaging the conductive and thermally conductive member 10 with the ground terminal 60.

[0075] Furthermore, regarding the substrate 50, it is preferable that the portion other than the grounding terminal is insulated. Since the conductive and heat-conducting component 10 could short-circuit and cause a malfunction if it comes into contact with other components, it is preferable that the portion other than the one connected to the grounding terminal 60 is insulated to protect other components. However, when the contact block 51 and through-hole 52 are provided on the substrate 50, these portions are not insulated and need to be conductive.

[0076] (Cooling components)

[0077] like Figures 1-3 As shown, the semiconductor device 1 of the present invention includes a conductive cooling member 40 disposed on the upper part of the semiconductor element 30.

[0078] Here, the cooling component 40 is a component that absorbs heat generated from the heat source (semiconductor element 30) and diffuses it to the outside. By connecting to the semiconductor element 30 via the conductive and thermally conductive component 10 described later, the heat generated by the semiconductor element 30 can be diffused to the outside, achieving high heat dissipation of the semiconductor device.

[0079] Furthermore, since the cooling component 40 is conductive, an electrically enclosed space can be formed by electrically connecting it to the grounding terminal 60 via the conductive heat-conducting component 10 (described later). Figures 1-3 The region A surrounded by the dashed line enhances the electromagnetic wave suppression effect of the semiconductor device 1.

[0080] The type of conductive cooling component 40 is not particularly limited, and can be appropriately selected according to the type of semiconductor device 1 according to the present invention. Examples include: heat sinks, coolers, heat fins, vapor chambers, chip pads, cooling fans, heat pipes, metal covers, housings, etc. Among these conductive cooling components, from the perspective of obtaining superior heat dissipation, conductive heat sinks, coolers, or heat fins are preferred. Furthermore, regarding the material constituting the conductive cooling component 40, from the perspective of improving thermal conductivity, it is preferable to contain metals such as aluminum, copper, and stainless steel, and / or materials such as graphite.

[0081] (Electrical and thermally conductive components)

[0082] like Figures 1-3 As shown, the semiconductor device 1 of the present invention is characterized in that it includes a conductive and thermally conductive member 10 disposed between the semiconductor element 30 and the conductive cooling member 40 and containing a cured resin, the conductive and thermally conductive member 10 being connected to a ground terminal 60 in the substrate 50, and the cooling member 40 being electrically connected to the ground terminal 60 via the conductive and thermally conductive member 10.

[0083] By placing a highly thermally conductive heat-conducting component 10 between the semiconductor element 30 and the cooling component 40, heat dissipation can be improved without reducing the electromagnetic wave suppression effect. Furthermore, by electrically connecting the cooling component 40 to the ground terminal 60 via the conductive heat-conducting component 10, such as... Figures 1-3 As shown, an electrically enclosed space A is formed within the semiconductor device 1 of the present invention, which improves the electromagnetic wave blocking effect of the conductive and heat-conducting component 10 and achieves excellent electromagnetic wave suppression effect.

[0084] Here, the shape of the conductive and heat-conducting component 10 is not particularly limited and can be appropriately changed according to the shape and / or size of the semiconductor element 30, the design of the semiconductor device 1, etc.

[0085] Specifically, such as Figure 1 and Figure 3 As shown, it can be disposed between the semiconductor element 30 and the cooling component 40, and can be disposed in the form of a bent sheet. Because the conductive and thermally conductive component 10 contains a cured resin and has a certain degree of flexibility, it can be formed without complex processes. Figure 1 and Figure 3 The shape shown. Additionally, as... Figure 2As shown, it can also be arranged in a manner that completely surrounds the semiconductor element 30 (encapsulating the upper surface 30b and side surface 30a of the semiconductor element 30).

[0086] Furthermore, from the viewpoint of achieving superior electromagnetic wave suppression, it is preferable to... Figure 1 and Figure 3 As shown, the conductive and heat-conducting component 10 is disposed to cover the semiconductor element 30 and abuts against at least a portion of the upper surface 30b and side surface 30a of the semiconductor element 30. Because the electrical connection between the cooling component 40 and the grounding terminal 60 can be efficiently ensured, an electrically enclosed space A can be formed more reliably.

[0087] Furthermore, from the same perspective, it is even better to have... Figure 2 As shown, the conductive and thermally conductive component 10 encapsulates the upper surface 30b and side surface 30a of the semiconductor element 30.

[0088] It should be noted that the conductive and heat-conducting component 10 can be composed of a single sheet or multiple sheets.

[0089] For example, in such Figure 1 and Figure 3 When the conductive and heat-conducting component 10 is provided as a curved sheet, it can be constructed from a single sheet. However, from the viewpoint of easily adjusting the thickness of the sheet, it is also possible to construct the conductive and heat-conducting component 10 from multiple sheets.

[0090] In addition, in such Figure 2 When the conductive and thermally conductive component 10 shown encapsulates the upper surface 30b and side surface 30a of the semiconductor element 30, it is possible to process one conductive and thermally conductive component 10, or to combine multiple conductive and thermally conductive components 10 to form the conductive and thermally conductive component 10.

[0091] Furthermore, the thickness T of the conductive and heat-conducting component 10 is not particularly limited and can be appropriately varied depending on the distance between the semiconductor element 30 and the cooling component 40, the design of the semiconductor device 1, etc. However, from the viewpoint of achieving a higher level of heat dissipation and electromagnetic wave suppression effect, it is preferable that the thickness T of the conductive and heat-conducting component 10 is 50 μm to 4 mm, more preferably 100 μm to 4 mm, and particularly preferably 200 μm to 3 mm. If the thickness T of the conductive and heat-conducting component 10 exceeds 4 mm, the thermal conductivity may decrease because the distance between the semiconductor element 30 and the cooling component 40 becomes longer. On the other hand, if the thickness T of the conductive and heat-conducting component 10 is less than 50 μm, the electromagnetic wave suppression effect may become smaller.

[0092] Here, the thickness T of the conductive and thermally conductive component 10 refers to, for example, Figures 1-3 As shown, the thickness T of the thickest portion of the conductive and thermally conductive component 10 on the semiconductor element 30 is independent of whether the conductive and thermally conductive component 10 is formed from a single sheet or multiple sheets.

[0093] The conductive and thermally conductive component 10 requires a cured resin. By using a cured resin, the conductive and thermally conductive component 10 can possess a certain degree of flexibility, thereby improving ease of manufacture.

[0094] It should be noted that the flexibility of the conductive and thermally conductive component 10 is better the higher it is; specifically, the preferred rubber Shore hardness (ASTM D2240) is in the range of 10 to 80.

[0095] It should be noted that, regarding the conductive and heat-conducting component 10, high conductivity is preferred from the perspective of achieving excellent electromagnetic wave suppression effect.

[0096] Specifically, the resistivity of the conductive and heat-conducting component 10 is preferably 0.15 Ω·m or less, more preferably 0.01 Ω·m or less, even more preferably 0.005 Ω·m or less, and particularly preferably 0.001 Ω·m or less. This is because by setting the resistivity of the conductive and heat-conducting component 10 to 0.15 Ω·m or less, a better electromagnetic wave suppression effect can be obtained.

[0097] Furthermore, the resistivity of the conductive and heat-conducting component 10 is preferably 0.00001 Ω·m or higher. The lower the resistivity, i.e. the higher the conductivity, the greater the electromagnetic wave shielding performance, thereby improving the electromagnetic wave suppression effect.

[0098] It should be noted that there is no particular limitation on the method for adjusting the conductivity (resistivity) of the conductive and heat-conducting component 10, but it can be adjusted by changing the type of adhesive resin, the material of the filler, the amount of the filler, and the orientation direction.

[0099] Furthermore, the conductive and heat-conducting component 10 is preferably 5 W / mK or higher, more preferably 10 W / mK or higher, and particularly preferably 20 W / mK or higher. This is to further improve the heat exchange efficiency between the semiconductor element 30 and the cooling component 40, and to further improve heat dissipation.

[0100] Furthermore, the conductive and heat-conducting component 10 preferably has magnetic properties. This is because, since the conductive and heat-conducting component 10 can have electromagnetic wave absorption properties, a more superior electromagnetic wave suppression effect can be obtained.

[0101] Here, there is no particular limitation on the method for adjusting the magnetism of the conductive and heat-conducting component 10, but the conductive and heat-conducting component 10 can contain magnetic powder or the like and its amount can be changed, thereby making the adjustment.

[0102] Furthermore, the conductive and thermally conductive component 10 preferably has adhesive or bonding properties on its surface. This is because it improves the adhesion between the conductive and thermally conductive component 10 and other components. Moreover, when the conductive and thermally conductive component 10 is composed of multiple sheets, it also improves the adhesion between the sheets.

[0103] It should be noted that there is no particular limitation on the method of imparting adhesiveness to the surface of the conductive and thermally conductive component 10. For example, it is possible to optimize the adhesive resin constituting the conductive and thermally conductive component 10 to make it adhesive, or an additional adhesive layer with adhesiveness can be provided on the surface of the conductive and thermally conductive component 10.

[0104] It should be noted that the material constituting the conductive and thermally conductive component 10 is not particularly limited as long as it has excellent electromagnetic wave absorption performance and thermal conductivity.

[0105] For example, from the perspective of achieving high levels of electromagnetic wave absorption performance and thermal conductivity, the conductive and thermally conductive component may contain adhesive resin, conductive and thermally conductive filler, and other components.

[0106] The materials constituting the conductive and heat-conducting component 10 will be described below.

[0107] Adhesive resin

[0108] The adhesive resin constituting the conductive and thermally conductive component is a cured product of the resin component that forms the substrate of the conductive and thermally conductive component. There is no particular limitation on its type; known adhesive resins can be appropriately selected. For example, thermosetting resins are listed as one type of adhesive resin.

[0109] Examples of thermosetting resins include, for instance, cross-linked rubbers, epoxy resins, polyimide resins, bismaleimide resins, benzocyclobutene resins, phenolic resins, unsaturated polyesters, diallyl phthalate resins, silicones, polyurethanes, polyimide silicones, thermosetting polyphenylene ethers, and thermosetting modified polyphenylene ethers. These resins can be used alone or in combination of two or more.

[0110] It should be noted that, for example, the crosslinkable rubbers mentioned include: natural rubber, butadiene rubber, isoprene rubber, nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber, ethylene propylene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, butyl rubber, halogenated butyl rubber, fluororubber, polyurethane rubber, acrylic rubber, polyisobutylene rubber, and silicone rubber. These rubbers can be used individually or in combination.

[0111] Furthermore, among the aforementioned thermosetting resins, silicone is preferred due to its excellent processability and weather resistance, as well as its tight fit and conformability to electronic components. There are no particular limitations on the type of silicone used; the appropriate type can be selected based on the intended purpose.

[0112] From the viewpoint of achieving the aforementioned processability, weather resistance, and tight adhesion, the silicone is preferably a silicone composed of a liquid silicone gel main agent and a curing agent. Examples of such silicones include addition-reaction type liquid silicones and thermally vulcanized compound silicones that use peroxides for vulcanization.

[0113] As the addition-reaction type liquid silicone, a two-component addition-reaction type silicone is preferred, which uses a vinyl-based polyorganosiloxane as the main agent and a Si-H-based polyorganosiloxane as the curing agent.

[0114] It should be noted that in the combination of the liquid silicone base agent and the curing agent, the preferred mixing ratio of the base agent and the curing agent by mass is base agent: curing agent = 35:65 to 65:35.

[0115] Furthermore, the content of the adhesive resin in the conductive and thermally conductive component is not particularly limited and can be appropriately selected according to the purpose. For example, from the viewpoint of ensuring the formability and / or tightness of the sheet, the content of the adhesive resin in the conductive and thermally conductive component is preferably 20% to 50% by volume, more preferably 30% to 40% by volume.

[0116] • Electrically conductive and thermally conductive filler

[0117] The conductive and thermally conductive component contains a conductive and thermally conductive filler (hereinafter sometimes simply referred to as "thermally conductive filler") within the adhesive resin. This conductive and thermally conductive filler is a component used to improve the thermal and electrical conductivity of the sheet.

[0118] There are no particular limitations on the type of thermally conductive filler here, but fibrous thermally conductive fillers are preferred from the perspective of achieving higher thermal conductivity.

[0119] It should be noted that the term "fibrous" in the context of the fibrous thermally conductive filler refers to a shape with a high aspect ratio (approximately 6 or more). Therefore, in this invention, the fibrous thermally conductive filler includes not only fibrous or rod-shaped thermally conductive fillers, but also granular fillers or sheet-like thermally conductive fillers with a high aspect ratio.

[0120] Here, the type of fibrous thermally conductive filler is not particularly limited as long as it is a fibrous material with high thermal and electrical conductivity. Examples include: metals such as silver, copper, and aluminum; ceramics such as alumina, aluminum nitride, silicon carbide, and graphite; and carbon fibers.

[0121] Among these fibrous thermally conductive fillers, carbon fiber is preferred for achieving higher thermal and electrical conductivity.

[0122] It should be noted that the aforementioned conductive and thermally conductive filler can be used alone or in combination with two or more. Furthermore, when using two or more thermally conductive fillers, either any fibrous thermally conductive filler can be used, or fibrous thermally conductive fillers can be mixed with thermally conductive fillers of other shapes.

[0123] There are no particular limitations on the type of carbon fiber, and it can be appropriately selected according to the purpose. For example, pitch-based carbon fibers, PAN-based carbon fibers, carbon fibers obtained by graphitizing PBO fibers, and carbon fibers synthesized by methods such as arc discharge method, laser evaporation method, CVD method (chemical vapor deposition), and CCVD method (catalytic chemical vapor deposition) can be used. Among these carbon fibers, carbon fibers obtained by graphitizing PBO fibers and pitch-based carbon fibers are more preferred from the perspective of obtaining high thermal conductivity and electrical conductivity.

[0124] Additionally, the carbon fibers can be surface-treated, either partially or entirely, as needed. Examples of such surface treatments include oxidation, nitration, nitration, sulfonation, or treatments that attach or bond metals, metal compounds, organic compounds, etc., to the functional groups introduced onto the surface or the carbon fibers through these treatments. Examples of such functional groups include hydroxyl, carboxyl, carbonyl, nitro, and amino groups.

[0125] Furthermore, there is no particular limitation on the average fiber length (average major axis length) of the fibrous thermally conductive filler, and it can be appropriately selected. However, from the perspective of actually obtaining high thermal conductivity, the average fiber length of the fibrous thermally conductive filler is preferably in the range of 50 μm to 300 μm, more preferably in the range of 75 μm to 275 μm, and particularly preferably in the range of 90 μm to 250 μm.

[0126] Furthermore, there is no particular limitation on the average fiber diameter (average minor axis length) of the fibrous thermally conductive filler, and it can be appropriately selected. However, from the perspective of actually obtaining high thermal conductivity, the average fiber diameter of the fibrous thermally conductive filler is preferably in the range of 4 μm to 20 μm, and more preferably in the range of 5 μm to 14 μm.

[0127] Regarding the aspect ratio (average major axis length / average minor axis length) of the fibrous thermally conductive filler, from the perspective of practically obtaining high thermal conductivity, a fibrous thermally conductive filler with an aspect ratio of 6 or more is used, and the aspect ratio of the fibrous thermally conductive filler is preferably 7 to 30. Although improvements in thermal conductivity can be seen even when the aspect ratio is small, a large improvement in properties cannot be obtained due to reduced orientation, so the aspect ratio is set to 6 or more. On the other hand, if the aspect ratio exceeds 30, sufficient thermal conductivity may not be obtained due to reduced dispersibility in the conductive and thermally conductive components.

[0128] Here, the average major axis length and average minor axis length of the fibrous thermally conductive filler can be measured by means of, for example, a microscope, a scanning electron microscope (SEM), and the average value can be calculated based on multiple samples.

[0129] Furthermore, the content of the conductive thermally conductive filler in the conductive thermally conductive component is not particularly limited and can be appropriately selected according to the purpose. However, the content of the conductive thermally conductive filler in the conductive thermally conductive component is preferably 4% to 40% by volume, more preferably 5% to 30% by volume, and particularly preferably 6% to 20% by volume. If the content is less than 4% by volume, it may be difficult to obtain a sufficiently low thermal resistance, while if the content is greater than 40% by volume, it may affect the formability of the conductive thermally conductive component and the orientation of the fibrous thermally conductive filler.

[0130] Furthermore, in the conductive and thermally conductive component, the conductive and thermally conductive filler is preferably oriented in one or more directions. This is because by orienting the thermally conductive filler, higher thermal conductivity and / or electromagnetic wave absorption can be achieved.

[0131] For example, when it is desired to improve the thermal conductivity and electrical conductivity of the conductive and thermally conductive component, and to enhance the heat dissipation and electromagnetic wave suppression effects of the semiconductor device of the present invention, the thermally conductive filler can be oriented approximately perpendicular to the sheet surface. On the other hand, when the current flow in the conductive and thermally conductive component is changed, the thermally conductive filler can be oriented approximately parallel to the sheet surface or in other directions.

[0132] Here, the direction that is substantially perpendicular or substantially parallel to the sheet surface refers to a direction that is substantially perpendicular or substantially parallel to the sheet surface. However, the orientation of the conductive and thermally conductive filler may deviate slightly during manufacturing, so in this invention, a deviation of approximately ±20° from the direction perpendicular or parallel to the sheet surface is permissible.

[0133] It should be noted that there is no particular limitation on the method for adjusting the orientation angle of the conductive and thermally conductive filler. For example, by manufacturing a sheet molded body in the initial state of the conductive and thermally conductive component, and adjusting the cutting angle while the fibrous thermally conductive filler is oriented, the orientation angle can be adjusted.

[0134] Inorganic fillers

[0135] In addition to the aforementioned adhesive resin and conductive thermally conductive fibers, the conductive and thermally conductive component may further include inorganic fillers. This is intended to further improve the thermal conductivity of the conductive and thermally conductive component and enhance the strength of the sheet.

[0136] The inorganic filler material is not particularly limited in terms of its shape, material, average particle size, etc., and can be appropriately selected according to the purpose. Examples of possible shapes include spherical, ellipsoidal, blocky, granular, flat, and needle-like shapes. Among these shapes, spherical and elliptical shapes are preferred from a filling perspective, with spherical shapes being particularly preferred.

[0137] Examples of materials that can be used as inorganic fillers include: aluminum nitride (AlN), silicon dioxide, bauxite (alumina), boron nitride, titanium dioxide, glass, zinc oxide, silicon carbide, silicon, silicon oxide, alumina, and metal particles. These materials can be used individually or in combination. Among these materials, bauxite, boron nitride, aluminum nitride, zinc oxide, and silicon dioxide are preferred, and bauxite and aluminum nitride are particularly preferred from the perspective of thermal conductivity.

[0138] Alternatively, the inorganic filler can also be a surface-treated filler. If the inorganic filler is treated with a coupling agent as a surface treatment, the dispersibility of the inorganic filler is improved, and the flexibility of the conductive and thermally conductive components is enhanced.

[0139] The average particle size of the inorganic filler can be appropriately selected according to the type of inorganic material.

[0140] When the inorganic filler is bauxite, its average particle size is preferably 1 μm to 10 μm, more preferably 1 μm to 5 μm, and particularly preferably 4 μm to 5 μm. If the average particle size is less than 1 μm, the viscosity increases, making mixing difficult. On the other hand, if the average particle size is greater than 10 μm, the thermal resistance of the conductive and thermally conductive component may increase.

[0141] Furthermore, when the inorganic filler is aluminum nitride, its average particle size is preferably 0.3 μm to 6.0 μm, more preferably 0.3 μm to 2.0 μm, and particularly preferably 0.5 μm to 1.5 μm. If the average particle size is less than 0.3 μm, the viscosity increases, which may make mixing difficult; if the average particle size is greater than 6.0 μm, the thermal resistance of the conductive and thermally conductive component may increase.

[0142] It should be noted that the average particle size of the inorganic filler can be determined by, for example, a particle size analyzer or a scanning electron microscope (SEM).

[0143] Magnetic metal powder

[0144] Furthermore, it is preferable that the conductive and thermally conductive component, in addition to the aforementioned adhesive resin, fibrous thermally conductive fibers, and inorganic fillers, also contains magnetic metal powder. By including this magnetic metal powder, the magnetism of the conductive and thermally conductive component can be improved, and the electromagnetic wave suppression effect of the semiconductor device can be enhanced.

[0145] Regarding the type of magnetic metal powder, there are no particular limitations, except that it can improve the magnetism of the conductive and heat-conducting component and enhance electromagnetic wave absorption; any known magnetic metal powder can be appropriately selected. For example, amorphous metal powder and crystalline metal powder can be used. Examples of amorphous metal powders include Fe-Si-B-Cr, Fe-Si-B, Co-Si-B, Co-Zr, Co-Nb, and Co-Ta metal powders. Examples of crystalline metal powders include pure iron, Fe-based, Co-based, Ni-based, Fe-Ni-based, Fe-Co-based, Fe-Al-based, Fe-Si-based, Fe-Si-Al-based, and Fe-Ni-Si-Al-based metal powders. Furthermore, as the crystalline metal powder, microcrystalline metal powders obtained by adding trace amounts of N (nitrogen), C (carbon), O (oxygen), B (boron), etc., to crystalline metal powder to refine it can also be used.

[0146] It should be noted that the magnetic metal powder mentioned above can also be a mixture of two or more magnetic metal powders with different materials and / or different average particle sizes.

[0147] Furthermore, regarding the magnetic metal powder, it is preferable to adjust its shape to spherical or flat. For example, to improve filling properties, it is preferable to use magnetic metal powder with a particle size of several μm to tens of μm and in a spherical shape. Such magnetic metal powder can be manufactured by, for example, atomization or thermal decomposition of metal carbonyl groups. Atomization is a method that has the advantage of easily producing spherical powder by spraying molten metal from a nozzle and a jet of air, water, inert gas, etc., onto the flowing molten metal to solidify it into droplets. When manufacturing amorphous magnetic metal powder by atomization, in order to prevent the molten metal from crystallizing, it is preferable to set the cooling rate to 1 × 10⁻⁶. 6 Approximately (K / s).

[0148] When amorphous alloy powder is manufactured using the aforementioned atomization method, its surface can be made smooth. If this amorphous alloy powder, with its minimal surface roughness and small specific surface area, is used as a magnetic metal powder, its filling properties in adhesive resins can be improved. Furthermore, coupling treatment can further enhance its filling properties.

[0149] It should be noted that, in addition to the aforementioned adhesive resin, fibrous thermally conductive filler, inorganic filler, and magnetic metal powder, the conductive and thermally conductive component may also contain other components as appropriate for the purpose.

[0150] Other components include, for example: thixotropic agents, dispersants, curing accelerators, retarders, micro-tackifiers, plasticizers, flame retardants, antioxidants, stabilizers, colorants, etc.

[0151] <Methods for Manufacturing Semiconductor Devices>

[0152] There are no particular limitations on the method used to manufacture the semiconductor device of the present invention described above.

[0153] For example, in manufacturing Figure 1 In the case of the semiconductor device 1 in the embodiment shown, as a manufacturing method of the semiconductor device of the present invention, a manufacturing method comprising the following steps can be used: pressing a sheet-shaped conductive and thermally conductive member containing a resin-cured material onto a semiconductor element 30, thereby bonding the semiconductor element 30 to the conductive and thermally conductive member 10, and bonding the conductive and thermally conductive member 10 to a ground terminal 60.

[0154] By incorporating the above-mentioned processes, without going through complex procedures, semiconductor devices with excellent heat dissipation and electromagnetic wave suppression effects can be manufactured efficiently.

[0155] It should be noted that in the manufacturing method of the semiconductor device of the present invention, there are no particular limitations on the steps other than the step of pressing the conductive and thermally conductive component 10 described above, and known manufacturing methods can be appropriately used.

[0156] Example

[0157] Next, the present invention will be specifically described based on embodiments. However, the present invention is not limited to the following embodiments.

[0158] (Example 1)

[0159] In Example 1, the 3D electromagnetic field simulator ANSYS HFSS (manufactured by ANSYS) was used to create, as shown in Example 1. Figure 5 The analytical models of the semiconductor devices shown in (a) and (b) (analytical models of the present invention and comparative examples) were used to evaluate the electromagnetic wave suppression effect.

[0160] Here, the conductive and thermally conductive component 10 for the semiconductor device model uses a material obtained as follows: a two-component addition-reactive liquid silicone is used as a resin binder; bauxite (manufactured by DENKA Corporation) with an average particle size of 4 μm is used as a thermally conductive filler; and pitch-based carbon fibers ("thermally conductive fibers," manufactured by Nippon Graphite Fiber Co., Ltd.) with an average fiber length of 200 μm are used as a fibrous, conductive, and thermally conductive filler. These materials are dispersed in a volume ratio of two-component addition-reactive liquid silicone: bauxite particles: pitch-based carbon fibers = 35 vol%: 53 vol%: 12 vol% to prepare a silicone composition (sheet composition). Regarding the obtained thermally conductive sheet, the average thermal conductivity in the vertical direction (calculated by summing the surface thermal resistance and the internal thermal resistance) is shown to be 15 W / m·K, as determined according to ASTM D5470. The magnetic and dielectric properties of the sheet are values ​​obtained by measuring the S-parameter method. Measurements taken in accordance with JIS K7194 show that the resistivity of the sheet is 0.1 Ω·m. It should be noted that the dimensions of the conductive and heat-conducting component 10 are 22 mm × 22 mm, and the thickness T is 1 mm.

[0161] As a simulation model, the magnetic and dielectric properties of the aforementioned sheet were used, and the analysis was conducted with resistivity conditions of 0.15 Ω·m, 0.015 Ω·m, and 0.0015 Ω·m.

[0162] In addition, the cooling component 40 (heat sink) for the model of the semiconductor device uses aluminum plate as material, and its size is set to 30mm×30mm and its thickness is set to 0.3mm.

[0163] (1) Figure 5(a) and (b) represent analytical models of the semiconductor device according to an example of the present invention, and respectively show the states observed from the upper surface portion side (surface side) and the lower surface portion side (back side). It should be noted that in Figure 5 In (a) and (b), the positions of the components constituting the semiconductor device are drawn in perspective to clearly show the positional relationships.

[0164] The cross-sectional structure of the analytical model in this invention example and Figure 1 Same, and as Figure 5 As shown in (a) and (b), the semiconductor element 30 is formed by resin molding covering a microstrip line (MSL) 31. The MSL 31 is configured such that copper signal lines (signal line dimensions: 2mm × 1mm × 0.02mm) are disposed on the surface side of a dielectric substrate 50 (substrate dimensions: 30mm × 30mm × 0.65mm), and a ground terminal 60 is disposed on the back side. The signal source of the semiconductor element 30 is simplified by this MSL 31, with its two ends designated as signal input and output terminals. Furthermore, a portion of the ground terminal 60 (the dimensions of the ground terminal under the substrate: 30mm × 30mm × 0.02mm, and the dimensions of the ground terminal exposed on the substrate: inner diameter 20mm × 20mm, outer diameter 22mm × 22mm, thickness 0.02mm) is provided on the substrate. It should be noted that the main body of the semiconductor element 30 (the portion molded from resin) is formed as a dielectric with a relative permittivity of 4 and a dielectric loss tangent of 0.01. It should be noted that the main body of semiconductor element 30 has dimensions of 16mm × 16mm × 0.7mm.

[0165] (2) In addition, as a comparative example, such as Figure 8 As shown in (a), an analysis model is made that is identical to the semiconductor device of the above embodiment except that the ground terminal 60 is not provided on the substrate and the conductive and heat-conducting component 10 is not connected to the ground terminal 60.

[0166] Furthermore, regarding the evaluation of electromagnetic wave suppression effectiveness, the maximum electric field strength at a location 3m away from the semiconductor device was calculated and expressed as the electric field strength (dBμV / m) corresponding to the frequency. The calculated electric field strength results are shown below. Figure 6 .

[0167] exist Figure 6 In the present invention examples and comparative examples, the calculated results of the electric field strength are shown when the conductive and thermally conductive components 10 with a strength of 0.15 Ω·m, 0.015 Ω·m, and 0.0015 Ω·m are used as conductive and thermally conductive components 10.

[0168] according to Figure 6As a result, in the analytical model of the present invention, compared with the analytical model of the comparative example, a good overall electromagnetic wave suppression effect (reduction of electric field strength) was confirmed.

[0169] Furthermore, in the analysis model of this invention, the resistivity of the conductive and heat-conducting component 10 is lower, and the analysis model using conductive and heat-conducting components 10 with 0.015 Ω·m and 0.0015 Ω·m can confirm a better electromagnetic wave suppression effect.

[0170] (Example 2)

[0171] (1) In Example 2, the semiconductor device model of the present invention example of Example 1 was fabricated using the three-dimensional electromagnetic field simulator. Figure 5 An analytical model of the semiconductor device as shown in (a) and (b) was constructed, and the electromagnetic wave suppression effect was evaluated.

[0172] It should be noted that the resistivity of the conductive and thermally conductive component 10 used in the semiconductor device model of this invention is set to 0.015 Ω·m.

[0173] (2) In addition, the conductive and thermally conductive component 10 used in the semiconductor device model of Example 2 of the present invention was made under the same conditions (the size, thickness, thermal conductivity, and resistivity were exactly the same) except that it contained magnetic powder (Fe-Si-B-Cr amorphous magnetic particles) and was given magnetism in such a way that the imaginary part μr” of the specific permeability was 3.

[0174] (3) Furthermore, the comparative example analysis model of Example 2 was also a model made under the same conditions (size, thickness, thermal conductivity, and resistivity) except that the conductive and thermally conductive component 10 used contained magnetic powder (Fe-Si-B-Cr amorphous magnetic particles) and was given magnetism in such a way that the imaginary part μr” of the specific permeability was 5.

[0175] Furthermore, the evaluation of the electromagnetic wave suppression effect was conducted in the same manner as in Example 1, calculating the electric field strength (dBμV / m) corresponding to the frequency. The calculated results are shown below. Figure 7 .

[0176] exist Figure 7 In this invention, the electric field strength obtained from the analysis model of the semiconductor device when the conductive and heat-conducting component 10 contains magnetic powder is denoted as "Example of the present invention containing magnetic powder (0.015 Ω·m)" and "Comparative example containing magnetic powder (0.015 Ω·m)", and the electric field strength obtained from the analysis model of the semiconductor device when the conductive and heat-conducting component 10 does not contain magnetic powder is denoted as "Example of the present invention without magnetic powder (0.015 Ω·m)".

[0177] according to Figure 7 As a result, with respect to either of the models in the present invention examples and comparative examples, superior electromagnetic wave suppression effects were confirmed when magnetic powder was contained in the conductive and thermally conductive component 10.

[0178] Industrial availability

[0179] According to the present invention, a semiconductor device that can be easily manufactured at low cost and has excellent heat dissipation and electromagnetic wave suppression effects can be provided.

Claims

1. A semiconductor device, characterized in that, have: Semiconductor devices are formed on a substrate; A conductive cooling component is disposed on the upper part of the semiconductor element; as well as A conductive and thermally conductive component, disposed between the semiconductor element and the cooling component, and containing a cured resin. The conductive and thermally conductive component is connected to a ground terminal in the substrate, and the cooling component is electrically connected to the ground terminal, arranged to cover the semiconductor element, and abutting against at least a portion of the upper surface of the semiconductor element and the lower surface of the cooling component. The thickness of the conductive and thermally conductive component is 50μm to 4mm, and the Shore hardness of the rubber measured under ASTM D2240 standard is 10 to 80.

2. The semiconductor device according to claim 1, characterized in that, The conductive and thermally conductive component encapsulates the upper surface and side surfaces of the semiconductor element.

3. The semiconductor device according to claim 1 or 2, characterized in that, The resistivity of the conductive and thermally conductive component is less than 0.15 Ω·m.

4. The semiconductor device according to claim 1 or 2, characterized in that, The resistivity of the conductive and thermally conductive component is 0.00001 Ω·m or higher.

5. The semiconductor device according to claim 1 or 2, characterized in that, The conductive and thermally conductive component is magnetic.

6. The semiconductor device according to claim 1 or 2, characterized in that, The conductive and thermally conductive component has adhesive or bonding properties on its surface.

7. The semiconductor device according to claim 1 or 2, characterized in that, The conductive and thermally conductive component is flexible.

8. The semiconductor device according to claim 1 or 2, characterized in that, The conductive and thermally conductive component contains a conductive filler.

9. The semiconductor device according to claim 8, characterized in that, The conductive filler is carbon fiber.

10. The semiconductor device according to claim 1 or 2, characterized in that, The portion of the substrate other than the ground terminal is insulated.

11. A method for manufacturing a semiconductor device, characterized in that, A method for manufacturing a semiconductor device according to any one of claims 1 to 10, comprising: The process of bonding the semiconductor element to the conductive and thermally conductive component by pressing a sheet-like conductive and thermally conductive component containing a cured resin onto the semiconductor element, and then bonding the conductive and thermally conductive component to a ground terminal. The conductive and thermally conductive component abuts against at least a portion of the upper surface of the semiconductor element and the lower surface of the cooling component. The thickness of the conductive and thermally conductive component is 50 μm to 4 mm, and the Shore hardness of the rubber of the conductive and thermally conductive component, as measured under ASTM D2240 standard, is 10 to 80.

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