Heat-conducting sheet holding body and manufacturing method of heat-dissipating device

Abstract

The present invention relates to a heat transfer sheet holding body and a manufacturing method of a heat releasing device. The heat transfer sheet holding body of the present invention sequentially comprises a long strip-shaped carrier film; a plurality of heat transfer sheets; and a long strip-shaped cover film covering the plurality of heat transfer sheets, the shortest distance between adjacent heat transfer sheets is 2 mm or more, the plurality of heat transfer sheets are arranged with a space in the length direction of the carrier film and the cover film, and the plurality of heat transfer sheets can be peeled from the cover film and the carrier film.

Description

[0001] This application is a divisional application of Chinese application number 202180070469.0, filed on October 14, 2021, entitled "Method for manufacturing a heat-conducting sheet holder and a heat-dissipating device". Technical Field

[0002] This invention relates to a method for manufacturing a heat-conducting sheet holder and a heat-dissipating device. Background Technology

[0003] In recent years, the increased heat generation caused by the high density of wiring and electronic components in semiconductor packages using multilayer wiring boards, as well as the increased heat generation per unit area caused by the high integration of semiconductor elements, has led to expectations for improving the heat dissipation of semiconductor packages.

[0004] A typical heat dissipation device is a simple device that uses heat-conducting lubricant or heat-conducting sheet to sandwich a heat-generating element such as a semiconductor package with a heat-dissipating element such as aluminum or copper, thereby dissipating heat. Generally, compared to heat-conducting lubricant, heat-conducting sheet is more convenient to operate when assembling heat dissipation devices.

[0005] As a thermally conductive sheet, resin sheets filled with thermally conductive fillers are known. As a resin sheet with excellent thermal conductivity filled with thermally conductive fillers, various resin sheets have been proposed in which inorganic particles with high thermal conductivity are selected as thermally conductive fillers, and the inorganic particles are oriented perpendicularly to the sheet surface.

[0006] For example, thermally conductive sheets with a thermally conductive filler (boron nitride) oriented in a direction substantially perpendicular to the sheet surface have been proposed (e.g., see Patent Document 1), and thermally conductive sheets with a structure in which carbon fibers dispersed in a gel-like substance are oriented perpendicular to the sheet surface (e.g., see Patent Document 2).

[0007] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2002-26202 Patent Document 2: Japanese Patent Application Publication No. 2001-250894 Summary of the Invention

[0008] The technical problem that the invention aims to solve A heat-generating device can be manufactured by sandwiching the heat-conducting sheet described in Patent Documents 1 and 2 between a heat-generating element such as a semiconductor package and a heat-generating element such as aluminum or copper, and sealing them together. However, due to the increasing demand for heat-generating devices, there is a need for a method that can efficiently manufacture heat-generating devices, as well as a heat-conducting sheet used in this method.

[0009] This disclosure is made in view of the foregoing, and its object is to provide a heat-conducting sheet holder capable of efficiently manufacturing a heat-exothermic device, and a method for manufacturing a heat-exothermic device using the heat-conducting sheet holder.

[0010] Means for solving technical problems The specific means used to solve the above-mentioned technical problems include the following methods.

[0011] <1> A heat-conducting sheet holder, comprising, in sequence: A long, strip-shaped support membrane; Multiple heat-conducting sheets; and A long strip of covering film covering the aforementioned multiple heat-conducting sheets. The aforementioned multiple heat-conducting sheets are arranged at intervals along the longitudinal direction of the aforementioned carrier film and the aforementioned covering film. The aforementioned multiple heat-conducting sheets can be peeled off from the aforementioned covering film and the aforementioned supporting film.

[0012] <2> according to <1> The heat-conducting sheet holder further comprises a release layer between the carrier film and the plurality of heat-conducting sheets, through which the plurality of heat-conducting sheets can be peeled off from the carrier film.

[0013] <3> according to <2> The heat-conducting sheet holder has a plurality of release layers arranged along the length of the carrier film, and one or more of the heat-conducting sheets are arranged in each of the plurality of release layers.

[0014] <4> according to <3> The heat-conducting sheet holder, when configured such that the cover film is vertically downward and the bearing film is vertically upward, has a convex shape when viewed from the width direction of the heat-conducting sheet holder, formed by the adjacent release layers and the gaps formed by the heat-conducting sheets respectively disposed on the adjacent release layers.

[0015] <5> according to <1> ~ <4> The heat-conducting sheet holder as described in any one of the following, wherein the peel force between the carrier film and the heat-conducting sheet is greater than the peel force between the cover film and the heat-conducting sheet.

[0016] <6> according to <1> ~ <5> The heat-conducting sheet holder as described in any one of the following statements, wherein the average thickness of the heat-conducting sheet is 50 μm to 500 μm.

[0017] <7> according to <1> ~ <6> The heat-conducting sheet holder as described in any one of the following statements, wherein the heat-conducting sheet contains a heat-conducting filler and a resin.

[0018] <8> according to <1> ~ <7> The heat-conducting sheet holder as described in any one of the above statements is wound into a roll along its length.

[0019] <9> according to <1> ~ <8> The heat-conducting sheet holder according to any one of the following, wherein, in the width direction orthogonal to the length direction of the carrier film and the cover film, the width of the carrier film and the cover film are greater than the width of the heat-conducting sheet.

[0020] <10> according to <1> ~ <9> The heat-conducting sheet holder as described in any one of the above, wherein the shortest distance between adjacent heat-conducting sheets is 2 mm or more.

[0021] <11> according to <1> ~ <10> The heat-conducting sheet holder as described in any one of the above-mentioned methods, wherein no scratches are produced on the surface of the carrier film.

[0022] <12> A method for manufacturing a heat-generating device, wherein the above-mentioned device is used <1> ~ <11> The heat-conducting sheet holder as described in any one of the above-mentioned heat-conducting sheet holders, and the method for manufacturing a heat-generating device by placing the aforementioned heat-conducting sheet between a heating element and a heat-generating element, comprises the following steps: The process of peeling the aforementioned covering film off the aforementioned heat-conducting sheet holder; In the heat-conducting sheet holder after the covering film has been peeled off, the process of pressing the heat-conducting sheet onto one of the heating element and the heat-releasing element. The process of peeling the aforementioned carrier film from the heat-conducting sheet to which one of the aforementioned heating element and the aforementioned heat-releasing element is bonded; and The process of pressing the other of the heating element and the heat-releasing element onto the side of the heat-conducting sheet opposite to the side where one of the heating element and the heat-releasing element is bonded.

[0023] Invention Effects According to this disclosure, a heat-conducting sheet holder capable of efficiently manufacturing a heat-exciting device and a method for manufacturing a heat-exciting device using the heat-conducting sheet holder can be provided. Attached Figure Description

[0024] Figure 1 A side view illustrating an example of the heat-conducting sheet holder of this disclosure.

[0025] Figure 2 To observe the corresponding side from the covering membrane 1 Figure 1 The diagram for region α, which is indicated by the dashed line.

[0026] Figure 3 This is a schematic diagram illustrating a portion of the manufacturing process in an example of a method for manufacturing a heat-generating device. Detailed Implementation

[0027] The following describes in detail the methods for implementing the present invention. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including step elements, etc.) are not essential unless specifically stated otherwise. The same applies to numerical values ​​and their ranges, which do not limit the present invention.

[0028] In this disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that cannot be clearly distinguished from other processes, as long as the purpose of the process is achieved.

[0029] In this disclosure, the numerical range represented by "~" includes the minimum and maximum values ​​recorded before and after "~".

[0030] In this disclosure, within the numerical ranges described in stages, the upper or lower limit value recorded in one numerical range can be replaced with the upper or lower limit value of other numerical ranges described in stages. Furthermore, within the numerical ranges described in this disclosure, the upper or lower limit value can also be replaced with the values ​​shown in the embodiments.

[0031] In this disclosure, the content of each component in the composition refers to the total content of the multiple substances present in the composition, unless otherwise specified.

[0032] In this disclosure, the particles corresponding to each component may include multiple types. When multiple particles corresponding to each component are present in the composition, the particle size of each component, unless otherwise specified, refers to the value of the mixture of the multiple particles present in the composition.

[0033] In this disclosure, the term "layer" includes, when observing the area where the layer exists, not only the case where it is formed on the entire area, but also the case where it is formed on only a part of the area.

[0034] In this disclosure, the term "layering" refers to stacking layers, which can be two or more layers combined together, or two or more layers that are detachable.

[0035] In this disclosure, the thickness of the layer is the value obtained by measuring the thickness of 5 points of the layer to be targeted and taking their arithmetic mean.

[0036] The thickness of a layer can be measured using a micrometer or similar tool. In this disclosure, when the thickness of a layer can be measured directly, a micrometer is used. On the other hand, when measuring the thickness of a single layer or the total thickness of multiple layers, the measurement can also be performed by observing a cross-section of the object being measured using an electron microscope.

[0037] In this disclosure, when describing embodiments with reference to the accompanying drawings, the configuration of the embodiments is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in the figures are schematic, and the relative sizes of the components are not limited thereto.

[0038] <Heat-conducting sheet retainer> The heat-conducting sheet holder disclosed herein comprises, in sequence: a strip-shaped carrier film; a plurality of heat-conducting sheets; and a strip-shaped cover film covering the plurality of heat-conducting sheets. The plurality of heat-conducting sheets are arranged at intervals in the longitudinal direction of the carrier film and the cover film, and the plurality of heat-conducting sheets can be peeled off from the cover film and the carrier film.

[0039] In this disclosed heat-conducting sheet holder, multiple heat-conducting sheets are arranged on a strip-shaped carrier film, allowing the multiple heat-conducting sheets to be conveyed along with the carrier film. Therefore, by conveying multiple heat-conducting sheets (after the cover film has been peeled off from the heat-conducting sheet holder) along with the carrier film while simultaneously attaching them to a heating element, heat-dissipating element, etc., the heat-conducting sheets can be continuously mounted on the heating element, heat-dissipating element, etc. This allows for the efficient manufacture of heat-dissipating devices.

[0040] The heat-conducting sheet holder disclosed herein is preferably configured to be wound into a roll along its length. Alternatively, the heat-conducting sheet holder can be wound onto a core. By pulling out the rolled heat-conducting sheet holder and peeling the cover film from the heat-conducting sheet, a roll-to-roll continuous process can be used to continuously install the heat-conducting sheet onto heating elements, heat-releasing elements, etc., enabling more efficient manufacturing of heat-releasing devices.

[0041] (Carrier membrane) The heat-conducting sheet holder disclosed herein includes an elongated carrier film. The carrier film is an elongated membrane component used for conveying the heat-conducting sheet, and multiple heat-conducting sheets are disposed on the carrier film along its length, either directly or via a release layer (described later), with spacing between them. The carrier film can be peeled off from the heat-conducting sheet.

[0042] As for the material of the carrier film, there are no particular limitations as long as it can transfer multiple heat-conducting sheets disposed on the carrier film directly or through a release layer, etc. Examples include polyethylene, polyester, polypropylene, polyethylene terephthalate, polyimide, polyetherimide, polyether naphthalate, methylpentene and other resins.

[0043] The carrier film can be a single-layer film containing at least one of the above-mentioned resins, or it can be a multilayer film consisting of two or more layers containing at least one of the above-mentioned resins.

[0044] From the viewpoint of easily peeling the carrier film from the heat-conducting sheets, a release layer can be provided between the carrier film and multiple heat-conducting sheets, allowing the carrier film to be peeled off from the multiple heat-conducting sheets via the release layer. The release layer can be, for example, a release film surface-treated with a silicone-based or silica-based release agent. The material of the release film surface-treated with the release agent is the same as that of the carrier film. Furthermore, the release layer, such as the release film, can also be provided on the carrier film via an adhesive layer. In the heat-conducting sheet holder of this disclosure, viewed from the carrier film side, a carrier film, an adhesive layer, a release layer, and heat-conducting sheets can be sequentially stacked.

[0045] The average thickness of the carrier film is not particularly limited and can be appropriately selected considering factors such as the strength of the carrier film and the heat transfer properties of the heat-conducting sheet. Specifically, the average thickness of the carrier film is preferably 25μm to 200μm, more preferably 50μm to 150μm, and even more preferably 50μm to 100μm.

[0046] When a release layer is provided between the carrier film and multiple heat-conducting sheets, there is no particular limitation on the average thickness of the release layer. From the viewpoint of the release properties of the heat-conducting sheets and the miniaturization of the heat-conducting sheet holder, it is preferably 0.01 μm to 30 μm, and more preferably 1 μm to 10 μm.

[0047] When the release layer is a release film that has been surface-treated with a release agent, the average thickness of the release film is not particularly limited. From the viewpoint of ensuring adhesive properties and miniaturizing the heat-conducting sheet body, it is preferably 2μm to 200μm, more preferably 25μm to 200μm, even more preferably 50μm to 150μm, and particularly preferably 50μm to 100μm.

[0048] When an adhesive layer is provided between the release layer and the carrier film, the adhesive used in the adhesive layer may include, for example, commonly used acrylic adhesives, natural rubber adhesives, synthetic rubber adhesives, silicone adhesives, and mixtures thereof. The adhesive layer may also contain components other than adhesives, such as crosslinking agents and adhesive-improving agents.

[0049] There is no particular limitation on the average thickness of the adhesive layer. From the viewpoint of ensuring adhesive properties and miniaturization of the heat-conducting sheet holder, it is preferably 2μm to 200μm, more preferably 5μm to 100μm, and even more preferably 10μm to 50μm.

[0050] (Covering film) The disclosed heat-conducting sheet retainer includes an elongated covering film. The covering film is an elongated component used to cover and protect multiple heat-conducting sheets. The covering film can be peeled off from the heat-conducting sheets.

[0051] There are no particular limitations on the cover film; examples that can be included in the carrier film include resin-based films, paper-based films such as high-grade paper, coated paper, kraft paper, cellophane, and recycled paper, and metal foils such as aluminum. Among these, from the viewpoint of easy peeling of the cover film from the heat-conducting sheet, a paper-based film is preferred.

[0052] The covering film can be a single-layer film formed from any of the above-mentioned films, metal foils, etc., or it can be a multilayer film with two or more layers of the above-mentioned films, metal foils, etc.

[0053] Alternatively, a release layer can be provided on the surface of the multiple heat-conducting sheets of the cover film, allowing the cover film to be peeled off from the multiple heat-conducting sheets via the release layer. The release layer can simply be a layer containing a release agent such as an organosilicon or silica-based agent. When the cover film is a paper film, from the viewpoint of preventing the release agent from penetrating into the paper film, a layer containing polyethylene or the like, which functions as a seepage-proofing agent, can be disposed between the layer containing the release agent and the paper film.

[0054] The average thickness of the cover film is not particularly limited, but from the viewpoint of the strength of the cover film and the miniaturization of the heat-conducting sheet holder, it is preferably 25 μm to 200 μm, more preferably 50 μm to 150 μm, and even more preferably 75 μm to 150 μm. Here, when a release layer or a layer including polyethylene or the like is provided on the surfaces of the multiple heat-conducting sheet sides of the cover film, the average thickness of the cover film refers to the total average thickness including the release layer, etc.

[0055] In the heat-conducting sheet holder disclosed herein, it is preferable that no scratches are generated on the surface of the cover film, the carrier film, or the release film, preferably on the surface of the heat-conducting sheet side, and more preferably, no scratches are generated due to shearing caused by slicing, laser processing, etc. It is particularly preferable that no scratches are generated on the surface of the cover film or the carrier film, and more preferably, no scratches are generated on the surface of the carrier film. When no scratches are generated on these films, when tensile stress or the like is applied to the heat-conducting sheet holder, the breakage or deformation of these films can be suppressed. As a result, problems such as the inability to continuously press the heat-conducting sheet onto the pressed body using the heat-conducting sheet holder, and the inability to accurately press the heat-conducting sheet onto the pressed body due to relative positional misalignment between multiple heat-conducting sheets in the heat-conducting sheet holder, can be suppressed. In particular, since no scratches are generated on the carrier film, even when using the material described later... Figure 3 When the continuous process in the method shown presses the heat-conducting sheet onto the press-up body, it can also preferably suppress the breakage of the carrier film and the positional deviation of the heat-conducting sheet on the carrier film caused by tensile stress, etc.

[0056] In the heat-conducting sheet holder disclosed herein, the peel force between the carrier film and the heat-conducting sheet is preferably greater than the peel force between the cover film and the heat-conducting sheet. Therefore, when the cover film is peeled from the heat-conducting sheet holder, peeling between the carrier film and the heat-conducting sheet, and adhesion of the heat-conducting sheet to the peeled-off cover film can be suppressed.

[0057] For example, the peel force between the cover film and the heat-conducting sheet and the peel force between the carrier film and the heat-conducting sheet can be adjusted by setting a release layer between the carrier film and multiple heat-conducting sheets, or by setting a release layer on the multiple heat-conducting sheet sides of the cover film, or by changing the type of release agent contained in these release layers.

[0058] When a release layer is provided between the carrier film and multiple heat-conducting sheets, it is preferable that the peel force between the release layer and the heat-conducting sheets is greater than the peel force between the cover film and the heat-conducting sheets.

[0059] The peel force between the cover film and the heat-conducting sheet is preferably 0 mN / 25 mm to 30 mN / 25 mm, more preferably 0 mN / 25 mm to 10 mN / 25 mm, and even more preferably 0 mN / 25 mm to 5 mN / 25 mm. Here, a peel force of 0 mN / 25 mm means that when the cover film is installed in a tensile testing machine in a way that it is stretched in a direction of 90° relative to the interface with the heat-conducting sheet, the cover film has already peeled off.

[0060] The peel strength between the cover film and the heat-conducting sheet disclosed herein is the maximum peel strength obtained by preparing a laminated film with a width of 25 mm, using a tensile testing machine, at a tensile speed of 100 mm / min and a temperature of 23 °C, by stretching the cover film in a 90° direction relative to the interface with the heat-conducting sheet, when the cover film is peeled from the heat-conducting sheet.

[0061] The peel force between the carrier film and the heat-conducting sheet, and the peel force between the release layer preferably disposed between the carrier film and the heat-conducting sheet and the heat-conducting sheet, are preferably 5mN / 25mm to 50mN / 25mm, more preferably 10mN / 25mm to 30mN / 25mm, and even more preferably 12mN / 25mm to 30mN / 25mm.

[0062] The peel strength between the carrier film or release layer and the heat-conducting sheet disclosed herein is the maximum peel strength obtained by preparing a laminated film with a width of 25 mm, using a tensile testing machine at a tensile speed of 100 mm / min and a temperature of 23°C, when the carrier film or release layer is stretched in a 90° direction relative to the interface with the heat-conducting sheet, and peeling the carrier film or release layer from the heat-conducting sheet.

[0063] The peel force between the carrier film and the heat-conducting sheet (preferably the peel force between the release layer and the heat-conducting sheet configured between the carrier film and the heat-conducting sheet) is preferably greater than the peel force between the cover film and the heat-conducting sheet, and the difference between them is preferably 5mN / 25mm to 30mN / 25mm, more preferably 10mN / 25mm to 25mN / 25mm, and even more preferably 15mN / 25mm to 20mN / 25mm.

[0064] From the viewpoint of adhesion to the pressed body, sheet-like materials such as heat-conducting sheets can also have adhesive components on the surface facing the covering film. In the sheet-like material holder, the sheet-like material is held in a state where the covering film does not contact the sheet-like material, thus preventing the sheet-like material from adhering to the covering film due to adhesive components.

[0065] (Heat-conducting sheet) The heat-conducting sheet holder disclosed herein has a plurality of heat-conducting sheets between a strip-shaped carrier film and a strip-shaped cover film, the plurality of heat-conducting sheets being arranged at intervals in the longitudinal direction of the carrier film and the cover film.

[0066] There is no particular limitation on the average thickness of the heat-conducting sheet, which can be appropriately selected according to the purpose. Specifically, the average thickness of the heat-conducting sheet can be 50μm to 500μm, and from the perspective of thermal conductivity and sealing, it is preferably 60μm to 300μm, and more preferably 70μm to 200μm.

[0067] The shape of the main surface of the heat-conducting sheet is not particularly limited and can be appropriately changed according to the shape of the heat-generating and heat-releasing elements of the pressed body that forms the heat-conducting sheet. The shape of the main surface of the heat-conducting sheet can be circular, elliptical, polygonal, etc.

[0068] When the main surface of the heat-conducting sheet is polygonal, preferably rectangular or other quadrilateral shape, the length of one side can be 3mm to 100mm, or 5mm to 80mm.

[0069] When the main surface of the heat-conducting sheet is rectangular, it is preferable to arrange multiple heat-conducting sheets along the length direction of the carrier film with two opposite sides of the main surface facing each other. In this case, the ratio (length in the length direction) of the two sides along the length direction of the carrier film to the length of the two sides along the width direction orthogonal to the length direction of the carrier film (width direction length / length in the length direction) can be 0.1~5, 0.2~4, or 0.3~3.

[0070] Regarding multiple heat-conducting sheets arranged at intervals along the length of the carrier film and the cover film, the shortest distance between adjacent heat-conducting sheets can be 2 mm or more, or it can be 2 mm to 100 mm, or it can be 5 mm to 60 mm, or it can be 5 mm to 30 mm. With a minimum distance of 2 mm or more between adjacent heat-conducting sheets, when the heat-conducting sheets are pressed onto a heat-generating or heat-discharging body, interference from other heat-conducting sheets adjacent to the pressing object can be suppressed. This tends to suppress damage to other heat-conducting sheets and unintended adhesion to the pressed body caused by other heat-conducting sheets. Furthermore, with a minimum distance of 100 mm or less between adjacent heat-conducting sheets, there is a tendency for excellent productivity when pressing the heat-conducting sheets onto heat-generating or heat-discharging bodies.

[0071] The disclosed heat-conducting sheet holder can have multiple release layers arranged along the length direction of the carrier film between the carrier film and multiple heat-conducting sheets, and can also have one or more heat-conducting sheets arranged on each of the multiple release layers. Furthermore, two or more heat-conducting sheets can be arranged on each of the multiple release layers, and two to 50 heat-conducting sheets can also be arranged. By configuring multiple release layers, there is a tendency to suppress bending of the release layers and displacement of the heat-conducting sheets due to bending.

[0072] Furthermore, when the heat-conducting sheet holder of this disclosure is arranged such that the covering film is on the lower vertical side and the bearing film is on the upper vertical side, the shape of the gap formed by the adjacent release layers and the heat-conducting sheets respectively disposed on the adjacent release layers is preferably convex when viewed from the width direction of the heat-conducting sheet holder. As a result, on the surface of the heat-conducting sheets where the multiple release layers are disposed, the heat-conducting sheets are not disposed at both ends in the length direction, and there is a tendency for the bearing film to easily peel off from the heat-conducting sheets.

[0073] When the shape of the aforementioned gap is convex when viewed from the width direction of the heat-conducting sheet holder, the ratio of the upper edge of the convex shape in the vertical direction (the shortest distance between adjacent release layers) to the lower edge of the convex shape in the vertical direction (the lower edge of the convex shape / the upper edge of the convex shape in the vertical direction) can be greater than 1 and less than 300, or it can be 1.2 to 50, or it can be 1.5 to 10.

[0074] When the shape of the aforementioned gap is convex when viewed from the width direction of the heat-conducting sheet holder, the ratio of the height of the convex shape to the upper edge of the convex shape in the vertical direction, which is the shortest distance between adjacent release layers (upper edge of the convex shape in the vertical direction / height of the convex shape) can be 0.1~1000, 0.5~100, or 1~50.

[0075] Preferably, the width-direction lengths of both the carrier film and the cover film are greater than the width-direction length of the heat-conducting sheet. Because the carrier film is longer than the heat-conducting sheet, it can be easily transported and peeled off. Furthermore, because the cover film is longer than the heat-conducting sheet, it preferably protects the heat-conducting sheet, and the cover film can be easily peeled off.

[0076] The ratio of the width direction length of the carrier film to the width direction length of the heat-conducting sheet (width direction length of the carrier film / width direction length of the heat-conducting sheet) is preferably greater than 1 and less than 15, more preferably 1.05 to 10, and even more preferably 1.1 to 5.

[0077] The ratio of the width length of the cover film to the width length of the heat-conducting sheet (width length of the cover film / width length of the heat-conducting sheet) is preferably greater than 1 and less than 15, more preferably 1.05 to 10, and even more preferably 1.1 to 5.

[0078] From a transportability point of view, the heat-conducting sheet holder disclosed herein preferably does not have heat-conducting sheets disposed at both ends of the carrier film in the width direction, and more preferably has a plurality of sprocket holes for transporting the carrier film disposed at regular intervals along the length direction at both ends of the carrier film. Furthermore, by providing a plurality of sprocket holes at regular intervals, it is easy to arrange a plurality of heat-conducting sheets at regular intervals along the length direction of the carrier film according to the interval of the sprocket holes, and it also becomes easier to position the heat-conducting sheets when pressing them onto either the heating element or the heat-releasing element.

[0079] The center-to-center distance between adjacent sprocket holes can be 2mm to 10mm, or 3mm to 6mm.

[0080] In addition, the equivalent circle diameter of the sprocket hole can be 0.5mm~5mm, or 1mm~3mm.

[0081] From the viewpoint that the heat-conducting sheet used in this disclosure becomes more easily crushed and more easily bonded to the other of the heating element and the heat-releasing element under the high-temperature pressing conditions in the second pressing process described later, the compressive modulus of elasticity at a compressive stress of 0.1 MPa at 150°C is preferably 1.4 MPa or less, more preferably 1.3 MPa or less, and even more preferably 1.2 MPa or less. There is no particular limitation on the lower limit of the compressive modulus of elasticity at a compressive stress of 0.1 MPa at 150°C. The aforementioned compressive modulus of elasticity can be 0.5 MPa or more, and can also be 0.7 MPa or more.

[0082] The compressive modulus of thermally conductive sheets can be determined using a compression testing apparatus (e.g., the INSTRON 5948 MicroTester). A load is applied to the thermally conductive sheet along its thickness, and the displacement (mm) and load (N) are measured. The deformation (dimensionless) calculated using displacement (mm) / thickness (mm) is plotted on the horizontal axis, and the deformation calculated using load (N) / area (mm²) is plotted on the horizontal axis. 2 The calculated stress (MPa) is shown on the vertical axis, and the slope at the specified stress is taken as the compressive modulus (MPa). Specifically, for example, it can be measured using the method described in the examples.

[0083] In the heat-conducting sheet used in this disclosure, the adhesion strength at 25°C is preferably 5.0 N·mm or more, more preferably 6.0 N·mm or more, and even more preferably 7.0 N·mm or more. When the adhesion strength is 5.0 N·mm or more, when warping occurs in the heat-dissipating device equipped with the heat-conducting sheet, or the gap between the heating element and the heat-dissipating element increases, the peeling of the heat-conducting sheet from the heating element and the heat-dissipating element can be suppressed. There is no particular limitation on the upper limit of the adhesion strength. The above-mentioned adhesion strength can be 20.0 N·mm or less, or 15.0 N·mm or less.

[0084] The adhesion force of the heat-conducting sheet at 25°C can be measured using a universal physical property testing machine (e.g., Texture Analyser (Eiko Seiki Co., Ltd.)). At 25°C (room temperature), a 7mm diameter probe is pressed onto the heat-conducting sheet with a load of 40N and held for 10 seconds. The load and displacement curves when the probe is lifted are integrated to obtain the area, and the obtained area is taken as the adhesion force (N·mm) at 25°C.

[0085] The heat-conducting sheet used in this disclosure preferably satisfies the above conditions in terms of compressive modulus of elasticity at 150°C with a compressive stress of 0.1 MPa and adhesion at 25°C.

[0086] As mentioned above, heat-conducting sheets with a compressive stress of 0.1 MPa at 150°C and a compressive elastic modulus of 1.4 MPa or less are soft sheets, while heat-conducting sheets with an adhesion force of 5.0 N·mm or more at 25°C are highly adhesive sheets. Therefore, when attempting to install such soft or highly adhesive heat-conducting sheets onto heating or heat-dissipating elements, the following problems arise: the soft or highly adhesive heat-conducting sheets are prone to deformation and breakage; they cannot be easily peeled from protective sheets or other substrates; or the peeled heat-conducting sheets themselves deform or break, making them unusable in the installation of heating or heat-dissipating elements.

[0087] On the other hand, in the heat conduction sheet holder disclosed herein, when the heat conduction sheet is installed on the heating element, heat release element, etc., the above-mentioned picking is not required. The heat conduction sheet can be continuously installed on the heating element, heat release element, etc. while suppressing the deformation and breakage of the heat conduction sheet itself. Therefore, the processability of the heat conduction sheet and the manufacturing efficiency of the heat release device are excellent.

[0088] The aforementioned compressive modulus and adhesive force can be obtained, for example, by adjusting the proportions of the components used in the thermally conductive sheet.

[0089] The preferred composition of the heat-conducting sheet is described below.

[0090] Thermally conductive fillers The heat-conducting sheet preferably contains a heat-conducting filler. There are no particular restrictions on the heat-conducting filler, as long as it possesses thermal conductivity. Examples of heat-conducting fillers include particles of highly thermally conductive metals such as silver, copper, and aluminum; particles of ceramics such as alumina, aluminum nitride, boron nitride, and magnesium oxide; and graphite particles. Furthermore, one type of heat-conducting filler can be used alone, or two or more types can be used in combination.

[0091] As a thermally conductive filler, graphite particles are preferred, especially from the perspective of low thermal resistance and excellent thermal conductivity, and at least one type of graphite particles selected from flake particles, ellipsoidal particles and rod particles, as described later, are more preferred.

[0092] The mass-average particle size (D50) of the thermally conductive filler is measured using a laser diffraction particle size distribution device (such as the "Microtrac Series MT3300" manufactured by Nikkiso Corporation) that employs laser diffraction-scattering method. The particle size corresponds to the particle size at which the weight accumulation reaches 50% when plotting the weight accumulation particle size distribution curve from the small particle size side.

[0093] There are no particular restrictions on the particle size distribution of thermally conductive fillers. They can be monodisperse systems with a single peak in the particle size distribution (particle size as the horizontal axis and frequency as the vertical axis), or polydisperse systems with multiple peaks in the particle size distribution. In addition, the particle size distribution can be narrow or broad.

[0094] The content of thermally conductive filler in the thermally conductive sheet is preferably 15% to 50% by volume, more preferably 20% to 45% by volume, and even more preferably 25% to 40% by volume, from the perspective of balancing thermal conductivity and tightness with the heating element, heat-releasing element, etc.

[0095] When the content of thermally conductive filler is 15% by volume or more, there is a tendency for further improvement in thermal conductivity. When the content of thermally conductive filler is 50% by volume or less, there is a tendency for more effective suppression of adhesion and reduced tightness with heat-generating and heat-exciting elements.

[0096] The content (volume %) of thermally conductive filler is calculated using the following formula.

[0097] The content of thermally conductive filler (volume %) = (Aw / Ad) / ((Aw / Ad) + (Bw / Bd) + (Cw / Cd)) × 100 Aw: Mass composition of the thermally conductive filler (mass %) Bw: Mass composition of the resin (mass %) Cw: Mass composition (mass%) of any other components Ad: Density of thermally conductive filler Bd: Density of resin Cd: Density of any other component As a thermally conductive filler, it may contain at least one type of graphite particles selected from flake-shaped particles, ellipsoidal particles, and rod-shaped particles. Furthermore, when the graphite particles are flake-shaped, their surface direction may be oriented in the thickness direction; when the graphite particles are ellipsoidal, their long axis direction may be oriented in the thickness direction; or when the graphite particles are rod-shaped, their long axis direction may be oriented in the thickness direction.

[0098] With this configuration, the heat-conducting sheet has low thermal resistance and excellent thermal conductivity.

[0099] The preferred shape of the graphite particles is flake-shaped. By selecting flake-shaped graphite particles, thermal conductivity tends to be further improved. This can be attributed to, for example, the fact that flake-shaped graphite particles are more easily oriented in a specified direction within a thermally conductive sheet. Furthermore, the six-membered ring facet refers to the facet in a hexagonal crystal system where a six-membered ring is formed; it refers to the (0001) crystal facet.

[0100] Whether the six-membered ring facets in the crystallization of graphite particles are oriented along the plane of flake-like particles, the long axis of ellipsoidal particles, or the long axis of rod-like particles can be confirmed by X-ray diffraction. Specifically, the orientation of the six-membered ring facets in the crystallization of graphite particles is confirmed using the following methods.

[0101] First, a sample sheet for measurement is prepared, in which the plane orientation of the flake-shaped graphite particles, the long axis orientation of the ellipsoidal particles, or the long axis orientation of the rod-shaped graphite particles is aligned with the plane orientation of the sheet. Specific methods for preparing the sample sheet for measurement can be exemplified by the following methods.

[0102] A mixture of resin and graphite particles in an amount of 10% by volume or more relative to the resin is sheeted. The term "resin" as used herein is not particularly limited to any material that does not produce peaks that interfere with X-ray diffraction and is capable of forming a sheet. Specifically, amorphous resins with cohesive properties, such as acrylic rubber, NBR (acrylonitrile butadiene rubber), and SIBS (styrene-isobutylene-styrene copolymer), can be used.

[0103] The mixture is pressed into sheets to a thickness less than 1 / 10 of its original thickness, and multiple pressed sheets are stacked to form a laminate. This laminate is then further compressed to less than 1 / 10 of its original thickness three or more times to obtain a sample sheet for testing. Through this process, the graphite particles in the sample sheet are oriented in the following ways: flake-like particles with their surface direction aligned along the surface of the sample sheet; elliptical particles with their major axis aligned along the surface of the sample sheet; and rod-like particles with their major axis aligned along the surface of the sample sheet.

[0104] X-ray diffraction was performed on the surface of the sample sheet prepared as described above. The height H1 of the peak corresponding to the (110) plane of graphite that appears near 2θ=77° and the height H2 of the peak corresponding to the (002) plane of graphite that appears near 2θ=27° were measured. In the sample sheet prepared in this way, the value of H1 divided by H2 becomes 0~0.02.

[0105] Therefore, "the orientation of the six-membered toroidal surface in the crystallization of graphite particles in the planar direction when they are flake-shaped particles, in the direction of the long axis when they are ellipsoidal particles, and in the direction of the long axis when they are rod-shaped particles" refers to the state where the height of the peak corresponding to the (110) plane of graphite appearing near 2θ=77° divided by the height of the peak corresponding to the (002) plane of graphite appearing near 2θ=27° is 0~0.02.

[0106] In this disclosure, X-ray diffraction measurements are performed under the following conditions.

[0107] Device: "D8DISCOVER" manufactured by Bruker AXS Co., Ltd. X-ray source: CuKα with a wavelength of 1.5406 nm, 40 kV, 40 mA Step size (measured step length): 0.01° Step time: 720 sec Here, "when the graphite particles are flake-shaped, their surface direction is oriented in the thickness direction of the heat-conducting sheet; when they are ellipsoidal, their major axis direction is oriented in the thickness direction of the heat-conducting sheet; and when they are rod-shaped, their major axis direction is oriented in the thickness direction of the heat-conducting sheet" means that when the graphite particles are flake-shaped, the angle (hereinafter also referred to as "orientation angle") formed by their surface direction and the surface of the heat-conducting sheet is 60° or more; when the graphite particles are ellipsoidal, the angle formed by their major axis direction and the surface of the heat-conducting sheet is 60° or more; and when the graphite particles are rod-shaped, the angle formed by their major axis direction and the surface of the heat-conducting sheet is 60° or more. The orientation angle is preferably 80° or more, more preferably 85° or more, and even more preferably 88° or more.

[0108] The orientation angle is the average value of the angle (orientation angle) between the measurement surface direction and the surface (main surface) of the heat-conducting sheet when observing the cross-section of the heat-conducting sheet using SEM (scanning electron microscope) for any 50 graphite particles. For flaky particles, the average value is the average value of the angle (orientation angle) between the measurement surface direction and the surface (main surface) of the heat-conducting sheet when measuring the long axis direction and the long axis direction and the surface (main surface) of the heat-conducting sheet when measuring the long axis direction and the long axis direction and the surface (main surface) of the heat-conducting sheet when measuring the long axis direction and the long axis direction of the heat-conducting sheet.

[0109] There are no particular limitations on the particle size of the graphite particles. The average particle size of the graphite particles is preferably half to the average thickness of the thermally conductive sheet. When the average particle size of the graphite particles is more than half the average thickness of the thermally conductive sheet, heat conduction paths are formed efficiently within the sheet, tending to improve thermal conductivity. When the average particle size of the graphite particles is less than or equal to the average thickness of the sheet, there is a tendency to suppress graphite particle protrusion from the surface of the sheet and to achieve excellent surface adhesion.

[0110] Furthermore, when using the lamination and slicing method described in Japanese Patent Application Publication No. 2008-280496, the particle size of the graphite particles used as raw materials, in terms of mass average particle size, is preferably more than 1 / 2 times the average thickness of the thermally conductive sheet, and may also exceed the average thickness. The reason why the particle size of the graphite particles used as raw materials may exceed the average thickness of the thermally conductive sheet is that even if graphite particles with a particle size exceeding the average thickness of the thermally conductive sheet are included, since the thermally conductive sheet is formed by slicing each graphite particle individually, the graphite particles will not protrude from the surface of the thermally conductive sheet. In addition, when each graphite particle is sliced ​​in this way, multiple graphite particles penetrating in the thickness direction of the thermally conductive sheet are generated, which tends to form a thermally conductive path with extremely high efficiency and further improve thermal conductivity.

[0111] When using the stacked slicing method, the particle size of the graphite particles used as raw material is preferably 1 to 5 times the average thickness of the thermally conductive sheet, based on the mass average particle size. When the mass average particle size of the graphite particles is more than 1 times the average thickness of the thermally conductive sheet, the thermal conduction path is formed more efficiently, and the thermal conductivity is further improved. When it is less than 5 times the average thickness of the thermally conductive sheet, the area occupying the surface of the graphite particles can be prevented from becoming too large, and the reduction in adhesion can be suppressed.

[0112] The content of graphite particles in the thermally conductive filler relative to the total volume of the thermally conductive filler is preferably 50% to 100% by volume, more preferably 80% to 100% by volume, even more preferably 95% to 100% by volume, and particularly preferably 100% by volume.

[0113] Thermally conductive sheets, as graphite particles, can also include particles other than flake-shaped particles, ellipsoidal particles, and rod-shaped particles, such as spherical graphite particles, artificial graphite particles, flake graphite particles, acid-treated graphite particles, expanded graphite particles, and carbon fiber sheets.

[0114] As graphite particles, flake-shaped particles are preferred. From the viewpoint that they have high crystallinity and are easy to obtain large-diameter flakes, flake-shaped expanded graphite particles obtained by crushing expanded graphite that has been sheeted are preferred.

[0115] Resin The heat-conducting sheet preferably contains resin. By containing resin, the heat-conducting sheet exhibits excellent flexibility and tends to provide a good seal for heat-generating and heat-exciting elements.

[0116] There are no particular limitations on the type of resin used; for example, it can be a cured resin or a non-cured resin. Examples of resins include epoxy resin, silicone, acrylic resin, polyimide resin, bismaleimide resin, benzocyclobutene resin, phenolic resin, unsaturated polyester, diallyl phthalate resin, polyurethane, polyimide silicone, thermosetting polyphenylene ether, thermosetting modified polyphenylene ether, polybutene, polyisoprene, polysulfides, acrylonitrile rubber, silicone rubber, hydrocarbon resin, terpene resin, terpene phenolic resin, hydrogenated terpene phenol, etc. A single resin can be used, or two or more can be used in combination.

[0117] The resin content in the heat-conducting sheet is preferably selected based on the type of resin and the desired softness, adhesion, sealing properties, sheet strength, and hydrolysis resistance. For example, the resin content relative to the total volume of the heat-conducting sheet is preferably 25% to 75% by volume, more preferably 40% to 70% by volume, and even more preferably 50% to 65% by volume.

[0118] Other Ingredients Heat-conducting sheets may also contain components other than heat-conducting fillers and resins, depending on their purpose. For example, heat-conducting sheets intended to impart flame retardancy may also contain flame retardants.

[0119] There are no particular limitations on the flame retardant; it can be appropriately selected from commonly used flame retardants. For example, red phosphorus-based flame retardants and phosphate ester-based flame retardants can be cited. Among them, phosphate ester-based flame retardants are preferred from the perspectives of excellent safety and improved adhesion due to plasticizing effect.

[0120] As red phosphorus-based flame retardants, in addition to pure red phosphorus powder, various coatings and masterbatches of flame retardants can be used to improve safety or stability. Specifically, examples include RINKAFR, RINKAFE, RINKAAFQ, and RINKAFP (all trade names) manufactured by Phosphorus Chemical Industry Co., Ltd.

[0121] Examples of phosphate-based flame retardants include aliphatic phosphates such as trimethyl phosphate, triethyl phosphate, and tributyl phosphate; aromatic phosphates such as triphenyl phosphate, tricresyl phosphate, toluyl diphenyl phosphate, tri(xylyl) phosphate, toluyl-2,6-xylyl phosphate, tri(tert-butylphenyl) phosphate, tri(isopropylphenyl) phosphate, and triarylisopropyl phosphate; and aromatic condensed phosphates such as resorcinol bis(diphenyl) phosphate, bisphenol A bis(diphenyl) phosphate, and resorcinol bis(xylyl) phosphate.

[0122] Among them, bisphenol A bis(diphenyl phosphate) is preferred from the aspects of excellent hydrolysis resistance and excellent effect of improving adhesion due to plasticizing effect.

[0123] There is no particular limitation on the content of flame retardant in the heat-conducting sheet. It can be used in an amount that exerts flame retardancy, preferably 40% by volume or less. From the perspective of suppressing the deterioration of thermal resistance caused by the seepage of flame retardant components to the surface of the heat-conducting sheet, it is preferably 30% by volume or less.

[0124] The heat-conducting sheet may also contain additives such as antioxidants, free radical scavengers, and pH adjusters, and preferably contains antioxidants. The content of these additives in the heat-conducting sheet is preferably less than 5% by volume, more preferably less than 3% by volume, and even more preferably less than 1% by volume.

[0125] [Manufacturing method for heat-conducting sheet retainer] The manufacturing method of the heat-conducting sheet holder can be exemplified by the following steps. This manufacturing method includes the following steps: a step of preparing a composition comprising a heat-conducting filler, a resin, and other components as needed (also called a "preparation step"); a step of sheeting the aforementioned composition to obtain a sheet (also called a "sheet manufacturing step"); a step of overlapping multiple sheets of the aforementioned sheet, folding one of the sheets, or rolling one of the sheets to create a laminate (also called a "laminated body manufacturing step"); a step of slicing the side end faces of the aforementioned laminate (slicing step); and a step of sandwiching the sliced ​​multiple heat-conducting sheets between a cover film and a carrier film, and laminating the multiple heat-conducting sheets (lamination step).

[0126] The heat-conducting sheet contained in the heat-conducting sheet holder manufactured using this method is easy to form an efficient heat conduction path, and therefore tends to have high thermal conductivity and excellent sealing performance.

[0127] <Preparation Process> The composition constituting the heat-conducting sheet can be prepared by any method that can uniformly mix the heat-conducting filler, resin, and other components as needed, and there is no particular limitation. In addition, the composition can also be prepared using commercially available products. For details on the preparation of the composition, please refer to paragraph

[0033] of Japanese Patent Application Publication No. 2008-280496.

[0128] <Sheet Manufacturing Process> The sheet manufacturing process can be any method that can sheet the composition obtained in the previous process, and there is no particular limitation. For example, it is preferred to use at least one forming method selected from rolling, pressing, extrusion and finishing. For details of the sheet manufacturing process, please refer to paragraph

[0034] of Japanese Patent Application Publication No. 2008-280496.

[0129] <Laminated Body Fabrication Process> The laminate is formed in the laminate manufacturing process from sheets obtained in the previous process. The laminate is not limited to the method of stacking multiple independent sheets in sequence, but can also be formed by folding a single sheet without cutting, or by rolling a single sheet. For details of the laminate manufacturing process, please refer to paragraphs

[0035] to

[0037] of Japanese Patent Application Publication No. 2008-280496.

[0130] <Slicing Process> The slicing process can be any method that can slice the side end face of the laminate obtained in the previous process, and there is no particular limitation. From the viewpoint of utilizing graphite particles that penetrate through the thickness direction of the heat-conducting sheet to form a highly efficient heat conduction path and further improve the heat conduction, it is preferable to slice with a thickness of less than twice the mass average particle size of the graphite particles. For details of the slicing process, please refer to paragraph

[0038] of Japanese Patent Application Publication No. 2008-280496.

[0131] <Lamination Process> The lamination process can be any method that involves sandwiching multiple sliced ​​thermally conductive sheets between a cover film and a carrier film or a cover film and a release film, and then bonding the multiple thermally conductive sheets to the cover film and the carrier film or release film; there is no particular limitation. For example, the sliced ​​thermally conductive sheets can be cut to a specified size, and multiple thermally conductive sheets can be arranged on the cover film, carrier film, or release film. Then, the arranged multiple thermally conductive sheets can be sandwiched between the cover film and the carrier film or the cover film and the release film, and the thermally conductive sheets can be bonded to them to obtain a thermally conductive sheet holder. In addition to the above methods, for example, the sliced ​​thermally conductive sheets can be arranged on the cover film, carrier film, or release film, and the thermally conductive sheets can be cut to a specified size using punching or the like. Then, the cut multiple thermally conductive sheets can be sandwiched between the cover film and the carrier film or the cover film and the release film, and the thermally conductive sheets can be bonded to them to obtain a thermally conductive sheet holder.

[0132] For example, in the lamination process, long strips of heat-conducting sheets can be placed on a cover film, a support film, or a release film, and then cut using slicing, laser processing, or similar methods to place multiple heat-conducting sheets on the cover film, support film, or release film. However, when cutting the long strips of heat-conducting sheets using slicing, laser processing, or similar methods, the cover film, support film, or release film on which the long strips of heat-conducting sheets are placed is also partially cut in the thickness direction, resulting in scoring. When scoring occurs on these films, there is a risk that these films may break or deform when tensile stress is applied to the resulting heat-conducting sheet holder. As a result, the following problems are likely to occur: the heat-conducting sheet holder cannot be used to continuously press the heat-conducting sheet onto the pressed body; and the relative positions of multiple heat-conducting sheets in the heat-conducting sheet holder may deviate, making it impossible to press the heat-conducting sheet onto the pressed body with good precision. In particular, this problem is prone to occur when scratches are formed in the cover film or carrier film, and further, when scratches are formed in the carrier film, the following will be discussed. Figure 3 The continuous process in the method shown becomes more difficult.

[0133] Based on the above aspects, in the lamination process, it is preferable to arrange multiple heat-conducting sheets on a cover film, a support film, or a release film, or to cut the heat-conducting sheets arranged on the cover film, support film, or release film using punching or the like. This prevents or suppresses scoring on the cover film, support film, or release film, and preferably suppresses film breakage and deformation when tensile stress is applied to the heat-conducting sheet holder. Furthermore, unlike cutting long strips of heat-conducting sheets using slicing or laser processing, it is also easier to arrange multiple heat-conducting sheets such that the shortest distance between adjacent heat-conducting sheets is 2 mm or more.

[0134] <Manufacturing Method of Heat Exothermic Device> The method for manufacturing a heat-dissipating device disclosed herein is a method for manufacturing a heat-dissipating device in which the heat-conducting sheet is disposed between a heating element and a heat-dissipating element using a heat-conducting sheet holder disclosed herein. The method includes the following steps: a step of peeling the covering film from the heat-conducting sheet holder; a step of pressing the heat-conducting sheet onto one of the heating element and the heat-dissipating element in the heat-conducting sheet holder with the covering film peeled off; a step of peeling the carrier film from the heat-conducting sheet onto which one of the heating element and the heat-dissipating element is bonded; and a step of pressing the other of the heating element and the heat-dissipating element onto the side of the heat-conducting sheet opposite to the side onto which one of the heating element and the heat-dissipating element is bonded.

[0135] The heat-dissipating device obtained by the manufacturing method of this disclosure can efficiently transfer heat from the heating element to the heat-dissipating element by stacking the heating element and the heat-dissipating element through a heat-conducting sheet. In addition, the heat-conducting sheet can be easily removed when the heat-dissipating element is removed from the heating element.

[0136] The manufacturing method disclosed herein includes a step of peeling a cover film from a heat-conducting sheet holder. For example, when the heat-conducting sheet holder of this disclosure is wound into a roll, the cover film can be peeled off while the heat-conducting sheet holder is being pulled out on a pull-out roller that is capable of rotating the roll of heat-conducting sheet holder.

[0137] The manufacturing method disclosed herein includes a step (hereinafter also referred to as the "first pressing step") in which a heat-conducting sheet holder with a cover film removed is pressed onto one of a heating element and a heat-dissipating element. Alternatively, a roll-to-roll continuous process can be used to convey the heat-conducting sheet holder with the cover film removed and perform the process of pressing the heat-conducting sheet disposed in the heat-conducting sheet holder onto one of the heating element and the heat-dissipating element.

[0138] Examples of heat-generating elements include semiconductor packages with semiconductor chips mounted on a substrate, displays, LEDs, lamps, automotive power modules, and industrial power modules. Examples of heat-dissipating elements include heat sinks utilizing aluminum or copper sheets, aluminum or copper plates, etc.; aluminum or copper blocks connected to heat pipes; aluminum or copper blocks with cooling liquid circulated internally by a pump; Peltier elements and aluminum or copper blocks incorporating such elements.

[0139] The pressure and heating temperature in the first pressing process are not particularly limited, as long as they are sufficient to bond the heat-conducting sheet to either the heating element or the heat-releasing element. For example, the pressure can be 0.1 MPa to 4.0 MPa, or 0.15 MPa to 2.0 MPa. Similarly, the heating temperature can be 15°C to 100°C, or 20°C to 35°C. When pressing the heat-conducting sheet onto the heating element, the heating element can be heated to perform the pressing.

[0140] The manufacturing method disclosed herein includes a step of peeling a carrier film from a heat-conducting sheet to which one of a heating element and a heat-dissipating element is bonded. For example, after pressing the heat-conducting sheet onto one of the heating element and the heat-dissipating element in the aforementioned pressing step, the pressing is released, and the carrier film is peeled from the heat-conducting sheet. This step yields a heating element and a heat-dissipating element to which the heat-conducting sheet is bonded. Alternatively, a release layer can be provided between the carrier film and the heat-conducting sheet; in this case, the carrier film can also be peeled from the heat-conducting sheet via the release layer.

[0141] A roll-to-roll continuous process can be used to mount a carrier film from which the heat-conducting sheet has been peeled off onto a winding roller that can rotate upstream in the conveying direction. By rotating the winding roller and the aforementioned pull-out roller, the carrier film from which the heat-conducting sheet has been peeled off is recovered, while new heat-conducting sheets are conveyed, and the process of pressing with one of the new heating element and the heat-dissipating element is continuously performed.

[0142] The manufacturing method disclosed herein includes a step (hereinafter also referred to as the "second pressing step") of pressing one of the heating element and the other of the heat-dissipating element onto a side of a heat-conducting sheet opposite to the side to which one of the heating element and the heat-dissipating element is bonded. In this step, by pressing the heating element and the other of the heat-dissipating element onto the side to which the heat-conducting sheet is bonded, a heat-dissipating device is obtained, with the heat-conducting sheet positioned between the heating element and the heat-dissipating element. The preferred conditions for the pressure and heating temperature in the second pressing step are not particularly limited as long as they enable the heat-conducting sheet to be bonded to the other of the heating element and the heat-dissipating element. For example, the pressure can be 0.1 MPa to 2.0 MPa, or 0.15 MPa to 1.0 MPa. Furthermore, the heating temperature can be 80°C to 180°C, or 100°C to 170°C. When the heat-conducting sheet with one exposed side is pressed onto the heating element, the heating element can be heated to perform the pressing.

[0143] In the manufacturing method disclosed herein, the pressing conditions in the first pressing process and the second pressing process can also be adjusted such that the ratio (compression ratio) of the reduced thickness of the heat-conducting sheet after the second pressing process to the initial thickness of the heat-conducting sheet before the first pressing process reaches 5% to 35%.

[0144] (An example of a heat-conducting sheet retainer) The following uses Figure 1 as well as Figure 2 An example of a heat-conducting sheet retainer will be described. Figure 1 A side view illustrating an example of the heat-conducting sheet holder of this disclosure. Figure 2 To observe the corresponding side from the covering membrane 1 Figure 1 The diagram for region α (shown by the dashed line). Furthermore... Figure 2 The covering membrane 1 is omitted from the text. (For example...) Figure 1 As shown, the heat-conducting sheet holder 10 sequentially comprises a strip-shaped carrier film 3, multiple heat-conducting sheets 2, and a strip-shaped cover film 1. Furthermore, when viewed from the cover film 1 side, a release film 4 and an adhesive layer 5 are sequentially disposed between the carrier film 3 and the multiple heat-conducting sheets 2. Multiple release films 4 are disposed along the length of the carrier film 3, and nine heat-conducting sheets are disposed in each of the multiple release films. Additionally, Figure 1The region α, surrounded by dotted lines, corresponds to the gap formed by the adjacent release films 4 and the adjacent heat-conducting sheets 2 respectively disposed on the adjacent release films. Its shape is convex when viewed from the front.

[0145] The heat-conducting sheet holder 10 has a structure in which it is wound into a roll along the length direction on the core 6. Figure 1 In the process, a portion of the heat-conducting sheet retainer 10, which is wound into a roll, is pulled out. Furthermore, Figure 1 In the illustration, the pulled-out portion of the heat-conducting sheet holder 10 is shown with more emphasis than the core 6, but the relative size relationship between the pulled-out portion and the core 6 is not limited to this. Furthermore, Figure 1 In this process, the heat-conducting sheet holder 10 is wound into a roll with the covering film 1 on the outside and the carrying film 3 on the inside relative to the central axis. However, this is not a limitation. The heat-conducting sheet holder 10 can also be wound into a roll with the covering film 1 on the inside and the carrying film 3 on the outside relative to the central axis.

[0146] The width length of the carrier film 3 and the width length of the cover film 1 are larger than the width length of the heat-conducting sheet 2. No heat-conducting sheet 2 is disposed at either end of the carrier film 3 in the width direction; instead, multiple sprocket holes 7 for conveying the carrier film are provided at regular intervals along the length direction at both ends of the carrier film 3. These regularly spaced sprocket holes 7 are also used for positioning the heat-conducting sheet 2 during carrier film conveying.

[0147] (An example of a method for manufacturing a heat-generating device) The following uses Figure 3 An example of a method for manufacturing a heat-generating device will be described. Figure 3 This is a schematic diagram illustrating a portion of the manufacturing process in an example of a method for manufacturing a heat-generating device. Figure 3 The release film 4 and the adhesive layer 5 are omitted.

[0148] like Figure 3 As shown, a heat-conducting sheet holder 10, wound into a roll, is mounted on a pull-out roller 11 that can rotate in the direction of arrow X. A cover film 1 is peeled off from the heat-conducting sheet holder 10 pulled from the pull-out roller 11. A carrier film 3, with the cover film 1 peeled off, is mounted on a winding roller 16, which is a certain distance from the pull-out roller 11 and can rotate in the direction of arrow Z. In the conveying direction, a press 14 is provided between the pull-out roller 11 and the winding roller 16 to press the heat-conducting sheet 2 onto a semiconductor chip 13, which serves as a heating element.

[0149] A sprocket roller (not shown) is arranged between the pull-out roller 11 and the winding roller 16. Sprocket holes 7 are inserted into sprocket pins that are equally spaced on the surface of the sprocket roller. By rotating the pull-out roller 11 in the direction of arrow X and rotating the winding roller 16 in the direction of arrow Z, the heat-conducting sheet 2 arranged on the carrier film 3 is conveyed to the area facing the press 14.

[0150] After the heat-conducting sheet 2 disposed on the carrier film 3 is conveyed to the area facing the press 14, with the heat-conducting sheet 2 disposed between the press 14 and the semiconductor chip 13 disposed on the substrate 12, pressure is applied in the direction of arrow Y using the press 14 to press the heat-conducting sheet 2 onto the semiconductor chip 13. Furthermore, it is not limited to... Figure 3 The configuration shown allows one heat-conducting sheet 2 to be pressed onto one semiconductor chip 13. Alternatively, multiple heat-conducting sheets 2 can be pressed onto one semiconductor chip 13, or one or more heat-conducting sheets 2 can be pressed onto each chip of multiple semiconductor chips 13.

[0151] After the thermally conductive sheet 2 is pressed, the pull-out roller 11 and the winding roller 16 are rotated to peel the carrier film 3 from the thermally conductive sheet 2 pressed onto the surface of the semiconductor chip 13 in region 15. At this time, the carrier film 3 is peeled from the thermally conductive sheet 2 by a release layer (not shown), and the carrier film 3 with the release layer is recovered using the winding roller 16, thus obtaining a substrate with the semiconductor chip pressed onto the thermally conductive sheet 2.

[0152] Then, the next heat-conducting sheet 2, conveyed through the carrier film 3, is pressed onto the surface of the semiconductor chip 13 disposed on the next substrate with a semiconductor chip. By repeating the above process, the heat-conducting sheet 2 can be continuously mounted on the substrate with the semiconductor chip. In this way, the heat-conducting sheet can be pressed onto the heating element efficiently.

[0153] [Example] The present invention will now be described in more detail with reference to specific embodiments, but the invention is not limited to these embodiments. Furthermore, unless otherwise specified, "%" refers to a mass standard.

[0154] [Example 1] Multiple thermally conductive sheets manufactured by Showa Denko Materials Co., Ltd. were prepared. These sheets had a compressive modulus of 1.16 MPa at 150°C with a compressive stress of 0.10 MPa, an adhesion strength of 7.6 N·mm at 25°C, and a thermal conductivity of 16 W / (m·K). The sheets had a thickness of 150 μm, a length of 30 mm in the longitudinal direction, and a width of 50 mm. As the thermally conductive filler in these sheets, flake-shaped expanded graphite particles (Showa Denko Materials Co., Ltd. "HGF-L", mass average particle size: 270 μm; the orientation of the six-membered rings in the crystallization was confirmed in the planar direction of the flake-shaped particles using X-ray diffraction methods as described above).

[0155] Next, prepare a strip-shaped carrier film and a strip-shaped cover film as shown below. Additionally, prepare an adhesive layer and a release film disposed between the carrier film and the heat-conducting sheet.

[0156] (Carrier membrane) Long strip PET film: Toray Corporation's trade name Lumirror S30, thickness 75μm, width length 66mm. (Covering film) The elongated paper film is a laminate of silicone release agent, polyethylene, and kraft paper, marketed under the trade name SL-70S (U2) by Sumitomo Chemical Processing Paper Co., Ltd. It has a total thickness of 105 μm, a width length of 66 mm, and a peel strength of 0 mN / 25 mm against a heat-conducting sheet. Here, a peel strength of 0 mN / 25 mm means that peeling occurred when the cover film was mounted on a tensile testing machine and stretched at a 90° angle relative to the interface with the heat-conducting sheet.

[0157] (Adhesive layer) Acrylic resin double-sided tape: Neo Fix30, trade name of Nichiei Shinka Co., Ltd., 30μm thick, 50mm in width direction. (Mold release film) PET film treated with release agent: Nippa Corporation trade name FU, thickness 75μm, width length 50mm, peel strength for heat-conducting sheets 18mN / 25mm On both ends of the elongated carrier film in the width direction, along the length direction, a plurality of sprocket holes with a diameter of approximately 2.0 mm are provided at regular intervals, with a center-to-center distance of approximately 5.0 mm and a minimum distance between the center of the sprocket hole and the end of the carrier film in the width direction of approximately 3.0 mm. Furthermore, regarding the carrier film, an adhesive layer and a release film are sequentially disposed between the two ends where the sprocket holes are provided along the length direction. At this time, the release film is disposed such that the side treated with the release agent is opposite to the adhesive layer.

[0158] With the width ends of the release film aligning with the width ends of the heat-conducting sheets, six heat-conducting sheets are placed on each release film, and multiple release films with six heat-conducting sheets each are arranged along the length direction. At this point, the shortest distance between adjacent heat-conducting sheets is adjusted to 20mm.

[0159] Next, the two ends of the carrier film in the width direction and the two ends of the cover film in the width direction are arranged in a manner that makes them consistent when viewed from above. With multiple heat-conducting sheets sandwiched between the cover film and the carrier film, the multiple heat-conducting sheets are adhered to the cover film and the carrier film. This creates a strip-shaped heat-conducting sheet holder that sequentially comprises a strip-shaped carrier film, an adhesive layer, a release film, multiple heat-conducting sheets, and a strip-shaped cover film. By winding this strip-shaped heat-conducting sheet holder along its length onto a core with the carrier film side located on the core side, a roll-shaped heat-conducting sheet holder is obtained. Furthermore, in Figure 3 When using a roll-to-roll thermal conductive sheet holder in the roll-to-roll continuous process shown, the thermal conductive sheet holder needs to be pulled out and installed on the winding roller before the pressing process begins. In order to avoid producing thermal conductive sheets that cannot be used in the pressing process, no thermal conductive sheet is placed between the cover film and the carrier film in an area where the initial length pulled out from the roll-to-roll thermal conductive sheet holder is about 1m.

[0160] like Figure 3 As shown, a roll of heat-conducting sheet holder is mounted on a pull-out roller. A cover film is peeled off from the heat-conducting sheet holder pulled out from the pull-out roller. Simultaneously, a carrier film, with the cover film peeled off and the portion without heat-conducting sheet attached, is mounted on a winding roller. The pull-out roller and the winding roller are rotated to continuously convey multiple heat-conducting sheets on the carrier film. Using a press positioned between the pull-out roller and the winding roller in the heat-conducting sheet conveying direction, the heat-conducting sheets are pressed onto the surface of a semiconductor chip disposed on a substrate containing a semiconductor chip at 25°C and 0.8 MPa. After pressing, the winding roller is rotated to peel the carrier film off the heat-conducting sheet pressed onto the surface of the semiconductor chip, and the substrate containing the semiconductor chip with the pressed heat-conducting sheet is recovered. Then, the next heat-conducting sheet conveyed by the carrier film is pressed onto the surface of a semiconductor chip disposed on the next substrate containing a semiconductor chip. The above process is repeated, thereby continuously mounting heat-conducting sheets onto substrates containing semiconductor chips. Furthermore, in this embodiment, when the cover film is peeled off from the thermally conductive sheet through the release layer, the thermally conductive sheet is peeled off from the carrier film side, and the thermally conductive sheet will not be transferred to the cover film side. Moreover, it also suppresses the deviation of the bonding position on the semiconductor chip caused by the thermally conductive sheet being peeled off from the carrier film side.

[0161] [Example 2] Except that the release film in Example 1 is changed from the trade name FU of Nippa Corporation to the trade name X1-A3 of Nippa Corporation (thickness of 75μm, width length of 50mm, peel force for heat-conducting sheet of 38mN / 25mm), the strip-shaped heat-conducting sheet holder is manufactured in the same manner as in Example 1.

[0162] For the heat-conducting sheet holder manufactured in Example 2, the heat-conducting sheet was pressed onto the substrate with the semiconductor chip in the same manner as in Example 1. After pressing, when peeling the carrier film from the heat-conducting sheet pressed onto the surface of the semiconductor chip, it was more difficult to peel the carrier film from the heat-conducting sheet compared to Example 1, and the heat-conducting sheet was more prone to breakage.

[0163] [Example 3] Except that the release film in Example 1 is changed from the trade name FU of Nippa Corporation to the trade name 75E-0010 of Fujimori Industrial Co., Ltd. (thickness of 75μm, width length of 50mm, peel force for heat-conducting sheet of 50mN / 25mm), the strip-shaped heat-conducting sheet holder is manufactured in the same manner as in Example 1.

[0164] For the heat-conducting sheet holder manufactured in Example 3, the heat-conducting sheet was pressed onto the substrate with the semiconductor chip in the same manner as in Example 1. After pressing, when peeling the carrier film from the heat-conducting sheet pressed onto the surface of the semiconductor chip, it was more difficult to peel the carrier film from the heat-conducting sheet compared to Example 2, and the heat-conducting sheet was more prone to breakage.

[0165] [Example 4] Except that the cover film in Example 1 was changed from the trade name SL-70S (U2) of Sumitomo Chemical Processing Paper Co., Ltd. to the trade name FU of Nippa Co., Ltd. (thickness of 75μm, width length of 66mm, peel force for heat-conducting sheet of 18mN / 25mm), the strip-shaped heat-conducting sheet holder was manufactured in the same manner as in Example 1.

[0166] For the heat-conducting sheet holder manufactured in Example 4, the heat-conducting sheet was pressed onto the substrate with the semiconductor chip in the same manner as in Example 1. When peeling off the cover film, compared to Example 1, a portion of the heat-conducting sheet was more likely to adhere to the cover film side, and the heat-conducting sheet was more prone to breakage.

[0167] [Example 5] Except that the cover film in Example 1 was changed from the trade name SL-70S (U2) of Sumitomo Chemical Processing Paper Co., Ltd. to the trade name SP-8LK of Lintec Co., Ltd. (thickness of 88μm, width length of 66mm, peel force for heat-conducting sheet of 8mN / 25mm), the strip-shaped heat-conducting sheet holder was manufactured in the same manner as in Example 1.

[0168] For the heat-conducting sheet holder manufactured in Example 5, the heat-conducting sheet was pressed onto the substrate with the semiconductor chip in the same manner as in Example 1. When peeling off the cover film, compared to Example 1, a portion of the heat-conducting sheet was more likely to adhere to the cover film side, and the heat-conducting sheet was more prone to breakage.

[0169] [Example 6] Except that the release film in Example 4 is changed from the trade name FU of Nippa Corporation to the trade name 75E-0010 of Fujimori Industrial Co., Ltd. (thickness of 75μm, width length of 50mm, peel force for heat-conducting sheet of 50mN / 25mm), the strip-shaped heat-conducting sheet holder is manufactured in the same manner as in Example 4.

[0170] For the heat-conducting sheet holder manufactured in Example 6, the heat-conducting sheet was pressed onto the substrate with the semiconductor chip in the same manner as in Example 1. When peeling off the cover film, compared to Example 1, a portion of the heat-conducting sheet was more likely to adhere to the cover film side, and the heat-conducting sheet was more prone to breakage.

[0171] The publication of PCT / JP2020 / 039140 filed on October 16, 2020, is incorporated herein by reference in its entirety.

[0172] All documents, patent applications and technical standards described herein are incorporated herein by reference to the same extent as those specifically and separately described herein.

[0173] Symbol Explanation 1. Covering film 2. Heat-conducting sheet 3. Supporting membrane 4. Release film 5. Adhesive layer 6 cores 7 Sprocket Hole 10 Thermally conductive sheet retainer 11 Pull-out roller 12 substrate 13. Heating element 14 Pressing machine 15 regions 16 winding rollers

Claims

1. A heat-conducting sheet holder, comprising, in sequence: A long, strip-shaped support membrane; Multiple heat-conducting sheets; and A long strip of covering film covering the plurality of heat-conducting sheets, The shortest distance between adjacent heat-conducting sheets is 2 mm or more. The plurality of heat-conducting sheets are arranged at intervals along the length of the carrier film and the covering film. The plurality of heat-conducting sheets can be peeled off from the cover film and the carrier film. The average thickness of the heat-conducting sheet is 50μm to 500μm, and the adhesion of the heat-conducting sheet at 25°C is above 5.0N·mm and below 20.0N·mm.

2. The heat-conducting sheet holder according to claim 1, further comprising a release layer between the carrier film and the plurality of heat-conducting sheets, wherein the plurality of heat-conducting sheets can be peeled off from the carrier film via the release layer.

3. The heat-conducting sheet retainer according to claim 2, It has a plurality of release layers arranged along the length direction of the carrier film. Each of the plurality of release layers has one or more of the heat-conducting sheets disposed therein.

4. The heat-conducting sheet holder according to claim 3, wherein, When the cover film is arranged such that it is vertically downward and the support film is vertically upward, the shape of the gap formed by the adjacent release layers and the adjacent heat-conducting sheets respectively provided in the adjacent release layers is convex when viewed from the width direction of the heat-conducting sheet holder.

5. The heat-conducting sheet holder according to any one of claims 1 to 4, wherein, Compared to the peel force between the cover film and the heat-conducting sheet, the peel force between the carrier film and the heat-conducting sheet is greater.

6. The heat-conducting sheet holder according to any one of claims 1 to 5, wherein, The heat-conducting sheet contains a heat-conducting filler and a resin.

7. The heat-conducting sheet holder according to any one of claims 1 to 6, wherein it is wound into a roll along its length.

8. The heat-conducting sheet holder according to any one of claims 1 to 7, wherein, In the width direction orthogonal to the length direction of the carrier film and the cover film, the width of the carrier film and the width of the cover film are greater than the width of the heat-conducting sheet.

9. The heat-conducting sheet holder according to any one of claims 1 to 8, wherein, No scratches were produced on the surface of the carrier film.

10. A method for manufacturing a heat-releasing device, comprising the following steps: using a heat-conducting sheet holder as described in any one of claims 1 to 9, and placing the heat-conducting sheet between a heating element and a heat-releasing element to manufacture the heat-releasing device. The process of peeling the covering film off the heat-conducting sheet holder; In the heat-conducting sheet holder after the covering film has been peeled off, the process of pressing the heat-conducting sheet onto one of the heating element and the heat-releasing element. The process of peeling the carrier film off the heat-conducting sheet to which one of the heating element and the heat-releasing element is bonded; as well as The process of pressing the other of the heating element and the heat-releasing element onto the side of the heat-conducting sheet opposite to the side where one of the heating element and the heat-releasing element is bonded.

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