A method for manufacturing a heat-conducting sheet and a heat-conducting sheet

Abstract

The application discloses a heat-conducting sheet manufacturing method and a heat-conducting sheet, and relates to the technical field of heat-conducting sheet production.The method comprises the following steps: providing a conductor layer; adhering a first cover film to a first surface of the conductor layer; providing a second cover film, coating a thermosetting adhesive on a first surface of the second cover film to form a first adhesive layer, and coating a thermosetting adhesive on a second surface of the second cover film to form a second adhesive layer; adhering the second cover film to a second surface of the conductor layer to obtain a substrate, with the first adhesive layer located between the conductor layer and the second cover film; adhering the substrate to an aluminum plate to form a heat-conducting sheet; and performing compression molding of the heat-conducting sheet by using a compression equipment.The second cover film is coated with thermosetting adhesive on both surfaces, and the second cover film and the aluminum plate are formed by compression molding at one time, thereby reducing the traditional process and time of compressing the second cover film; the defects of traditional multiple transfer and multiple compression, labor consumption and slow production efficiency are overcome, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat-conducting sheet production, in particular to a heat-conducting sheet production method and a heat-conducting sheet. BACKGROUND

[0002] The heat-conducting sheet is usually a soft electric heating film element composed of high-temperature-resistant, high-heat-conducting, good-insulating and high-strength organic materials and metal heating film circuits. Since it is a sheet-shaped product, it has good flexibility, can be in close contact with the heated or heat-conducted object, and the shape can be designed as required to change the heating or heat conduction, can be more easily attached to the heated / heat-conducted object, and can more easily transfer heat to the desired place.

[0003] With the application and development of power battery technology, the demand of the client tends to be more integrated heating film solution, reducing manual work and improving production efficiency. Due to the limitations of equipment, materials and other factors in the heat-conducting sheet production industry, the traditional heating film structure is a PI film (referred to as A surface) covering brass or steel substrate structure after design and etching to form a chip; usually a covering film (referred to as B surface) is attached to the surface of the chip as an insulating layer.

[0004] With the upgrading of application requirements, an aluminum plate needs to be attached to the B surface. The general practice is: after the covering film is attached (B surface), it is pressed, and then baked for one hour; then a layer of glue is attached to the B surface using a film covering machine, and then pressed for a certain temperature and 25 minutes to make it a whole structure.

[0005] The heat-conducting sheet process of the above related technology is complex, needs multiple transfers and multiple pressings, consumes labor, has slow production efficiency, and multiple transfers and pressings result in low yield. SUMMARY

[0006] In order to solve the above problems and improve the production efficiency of the heat-conducting sheet, the present application provides a heat-conducting sheet production method and a heat-conducting sheet.

[0007] On the one hand, the present application provides a heat-conducting sheet production method, which adopts the following technical scheme:

[0008] A heat-conducting sheet production method, comprising the following steps:

[0009] providing a conductor layer, the conductor layer comprising opposite first and second surfaces;

[0010] attaching a first covering film to the first surface of the conductor layer;

[0011] providing a second covering film, applying a heat-set adhesive to the first surface of the second covering film to form a first adhesive layer, and applying a heat-set adhesive to the second surface of the second covering film to form a second adhesive layer;

[0012] attaching the second cover film on the second surface of the conductor layer to obtain a substrate, the first adhesive layer being located between the conductor layer and the second cover film;

[0013] attaching the substrate on the aluminum plate to form the heat-conducting sheet;

[0014] pressing the heat-conducting sheet into shape by a pressing device.

[0015] Optionally, after the second cover film is provided, the first surface of the second cover film is coated with thermosetting glue to form the first adhesive layer, and the second surface of the second cover film is coated with thermosetting glue to form the second adhesive layer, the method further comprises:

[0016] attaching the first release film on the first adhesive layer and attaching the second release film on the second adhesive layer.

[0017] Optionally, before the substrate is attached on the aluminum plate to form the heat-conducting sheet, the method further comprises:

[0018] tearing off the second release film;

[0019] attaching an isolation film at the half-groove corresponding to the aluminum plate on the second cover film;

[0020] attaching the substrate on the aluminum plate to form the heat-conducting sheet, an end of the aluminum plate being provided with a half-groove, the half-groove corresponding to the pad hole of the substrate.

[0021] Optionally, the half-groove of the aluminum plate is provided with a gasket, and the thickness of the gasket is the same as the thickness of the aluminum plate.

[0022] Optionally, the isolation film is a PI film.

[0023] Optionally, the thickness of the first adhesive layer and the second adhesive layer is 30-35 um.

[0024] Optionally, after the second cover film is attached on the second surface of the conductor layer to obtain a substrate, the method further comprises:

[0025] putting the substrate into a film pressing machine for pre-pressing to discharge air bubbles in the thermosetting glue.

[0026] Optionally, the pre-pressing temperature is 80-100℃, the pressure is 10-20N, and the pre-pressing time is 50-90s.

[0027] Optionally, before the second cover film is attached on the second surface of the conductor layer to obtain a substrate, the method further comprises:

[0028] tearing off the first release film.

[0029] In another aspect, the application provides a heat-conducting sheet, which adopts the following technical scheme:

[0030] A heat-conducting sheet comprises a first cover film, a conductor layer, a second cover film and an aluminum plate which are sequentially stacked;

[0031] The second cover film comprises a first surface close to the conductor layer and a second surface close to the aluminum plate, the first surface of the second cover film is coated with a first adhesive layer, and the second surface of the second cover film is coated with a second adhesive layer, both the first adhesive layer and the second adhesive layer are thermosetting glue; the first adhesive layer is used for bonding the conductor layer and the first surface of the second cover film, and the second adhesive layer is used for bonding the aluminum plate and the second surface of the second cover film.

[0032] In summary, the present application has at least one of the following beneficial technical effects:

[0033] 1. The second cover film is coated with thermosetting glue on both sides, and the second cover film and the aluminum plate are formed at one time, thereby reducing the traditional process and time of pressing the second cover film; the traditional multiple transfer and multiple pressing are overcome, the labor cost is saved, the production efficiency is improved, the yield is improved due to the reduction of the number of transfer and pressing, and the difficulty of foreign matter control is reduced.

[0034] 2. In the process of pasting the substrate on the aluminum plate, there is a half broken groove at the end of the aluminum plate for leaking the pad hole position, which is convenient for wiring. Therefore, when the substrate is pressed downward, the substrate at this position will be concave downward, which affects the overall quality of the heat-conducting sheet. Therefore, a gasket is arranged at the half broken groove, and the thickness of the gasket is equal to the thickness of the aluminum plate, so that the upper surface of the gasket is flush with the aluminum plate. When the substrate is pressed, the pad hole position of the substrate is in contact with the gasket, the flatness of the substrate is ensured, and the overall quality is improved. An isolation film is pasted at the pad hole position to prevent the second adhesive layer on the second cover film from being bonded with the gasket. After the aluminum plate is pasted, the gasket is easily removed. The isolation film made of PI film also plays a further protection role for the pad hole position, and improves the structural strength of this position. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a process flow chart of a heat-conducting sheet manufacturing method according to an embodiment of the present application;

[0036] Figure 2 is a structural schematic diagram of a heat-conducting sheet according to an embodiment of the present application;

[0037] Figure 3 is a structural schematic diagram of an aluminum plate according to an embodiment of the present application;

[0038] Figure 4 is a structural schematic diagram of a substrate according to an embodiment of the present application.

[0039] Explanation of reference signs: 1, conductor layer; 2, first cover film; 21, thermosetting adhesive layer; 3, second cover film; 31, first adhesive layer; 32, second adhesive layer; 4, aluminum plate; 41, half broken groove; 5, base plate; 51, isolation film; 10, heat conduction sheet. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0041] It should be noted that all directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directionality indications also change accordingly.

[0042] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal connection of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] In addition, if the present application has descriptions involving "first", "second" and the like, the "first", "second" and the like are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection claimed by the present application.

[0044] The present application discloses a heat conduction sheet manufacturing method.

[0045] Reference Figure 1 andFigure 2 A method for manufacturing a thermal conductive sheet comprises the following steps:

[0046] S1. Provide a conductor layer 1, wherein the conductor layer 1 includes a first surface and a second surface opposite to each other. The conductor layer 1 may be made of copper or steel.

[0047] S2. A first cover film 2 is attached to the first surface of the conductive layer 1. The first cover film 2 is a PI film, and a thermosetting adhesive layer 21 is provided between the first cover film 2 and the conductive layer 1. Specifically, the thin film conductive layer 1 is placed flat on a workbench, the release film on the surface of the first cover film 2 is removed, and the first cover film 2 is then attached to the first surface of the conductive layer 1. The conductive layer 1 is etched according to the circuit design pattern to obtain a chip.

[0048] PI film, or polyimide film, is a polymer material with excellent properties and is widely used in the electronics, aviation, automotive, microelectronics and other industries. PI film has the following characteristics: High temperature resistance: PI film has very good high temperature resistance and can usually work stably in the temperature range of -200°C to +400°C, and can even maintain its structure and performance at higher temperatures. Electrical insulation: PI film is a very excellent insulating material and is widely used in electrical insulation, electronic circuit boards, and protection of electronic components. Mechanical properties: PI film has high mechanical strength and flexibility and can adapt to various complex shapes and process requirements. Chemical stability: PI film is resistant to chemical corrosion and can resist erosion by many common chemicals. Dimensional stability: PI film is not easy to deform at high temperatures and has good dimensional stability.

[0049] S3. Provide a second covering film 3, apply thermosetting adhesive on the first surface of the second covering film 3 to form a first adhesive layer 31, and apply thermosetting adhesive on the second surface of the second covering film 3 to form a second adhesive layer 32. The thermosetting adhesive may be epoxy adhesive.

[0050] Optionally, after providing the second cover film 3, coating the first surface of the second cover film 3 with a thermosetting adhesive to form a first adhesive layer 31, and coating the second surface of the second cover film 3 with a thermosetting adhesive to form a second adhesive layer 32, the method further includes laminating a first release film on the first adhesive layer 31 and a second release film on the second adhesive layer 32. The first release film and the second release film may be silicone release films, polyolefin release films, polyimide (PI) release films, etc.

[0051] Optionally, a thermosetting adhesive is coated on the second covering film 3 by a laminating machine, and the thickness of the first adhesive layer 31 and the second adhesive layer 32 is 30 μm-35 μm to ensure good adhesion.

[0052] In the embodiment, after the double-sided coating of the second cover film 3 with the thermosetting adhesive, a release film is attached to protect the thermosetting adhesive of the first adhesive layer 31 and the second adhesive layer 32, and ensure the cleanliness of the thermosetting adhesive.

[0053] The release film, also known as the demolding film or isolation film 51, is a thin film material that plays an isolation role in the manufacturing and processing process. Its main function is to prevent the adhesion of materials or coatings to the surface of the substrate during the product processing process, facilitating subsequent processing or processing, especially when demolding, removing, bonding, etc. are required. The release film can protect the surface of the substrate from contamination or damage.

[0054] S4, the second cover film 3 is attached to the second surface of the conductor layer 1 to obtain a substrate 5, and the first adhesive layer 31 is located between the conductor layer 1 and the second cover film 3.

[0055] S41, before the second cover film 3 is attached to the second surface of the conductor layer 1 to obtain a substrate 5, it further includes tearing off the first release film.

[0056] S42, after the second cover film 3 is attached to the second surface of the conductor layer 1 to obtain a substrate 5, it further includes:

[0057] The substrate 5 is placed in a film pressing machine for pre-pressing to discharge air bubbles in the thermosetting adhesive.

[0058] Optionally, the pre-pressing temperature is 80-100°C, the pressure is 10-20N, and the pre-pressing time is 50-90s.

[0059] In the embodiment, the pressing roller in the film pressing machine extrudes the substrate 5, and then extrudes and discharges the air bubbles in the thermosetting adhesive on the first cover film 2 and the second cover film 3 in the substrate 5 at one time, improving the bonding firmness. And keep the pre-pressing temperature in the film pressing machine at 80-100°C to make the thermosetting adhesive bond firmly.

[0060] S5, the substrate 5 is attached to the aluminum plate 4 to form a heat-conducting sheet 10, which can be used in the new energy automobile industry for heating and / or heat dissipation of the battery.

[0061] Referring to Figure 3 and Figure 4 , S51, before the substrate 5 is attached to the aluminum plate 4 to form a heat-conducting sheet 10, it further includes:

[0062] tearing off the second release film;

[0063] attaching an isolation film 51 at the second cover film 3 corresponding to the aluminum plate 4 half-groove 41;

[0064] The substrate 5 is pasted on the aluminum plate 4 to form the heat-conducting sheet 10, and the aluminum plate 4 is provided with a half slot at the end thereof, and the half slot 41 corresponds to the pad hole of the substrate 5.

[0065] Optionally, the half slot 41 of the aluminum plate 4 is provided with a gasket, and the thickness of the gasket is the same as the thickness of the aluminum plate 4.

[0066] Optionally, the isolation film 51 is a PI film, and the thickness of the isolation film 51 is 25 um.

[0067] In the embodiment, in the process of pasting the substrate 5 on the aluminum plate 4, the half slot 41 is arranged at the end of the aluminum plate 4, and the half slot 41 is used for leaking the pad hole, so as to facilitate the wiring. Therefore, when the substrate 5 is pressed downward, the substrate 5 at the half slot 41 is concave downward, which affects the overall quality of the heat-conducting sheet 10. Therefore, the gasket is arranged at the half slot 41, and the thickness of the gasket is the same as the thickness of the aluminum plate 4, so that the upper surface of the gasket is flush with the aluminum plate 4. When the substrate 5 is pressed, the pad hole of the substrate 5 is in contact with the gasket, so as to ensure the flatness of the substrate 5 and improve the overall quality.

[0068] The isolation film 51 is pasted at the pad hole, so as to prevent the second adhesive layer 32 on the second cover film 3 from being bonded with the gasket. After the aluminum plate 4 is pasted, the gasket is easily removed. The isolation film 51 made of the PI film also protects the pad hole, and improves the structural strength.

[0069] S6, the heat-conducting sheet 10 is formed by a pressing device, and the pressing device is a film pressing machine. The heat-conducting sheet 10 is pressed for 180 degrees and 25 minutes to form an overall structure.

[0070] The scheme of the application pastes the second cover film 3 on both sides with the thermosetting adhesive, and the second cover film 3 and the aluminum plate 4 are pressed and formed at one time, so as to reduce the traditional pressing process and time of the second cover film 3. The scheme overcomes the defects of traditional multiple transfer and multiple pressing, saves labor, and improves the production efficiency. The scheme improves the yield and reduces the difficulty of foreign matter control and cost.

[0071] In the embodiment, the aluminum plate 4 is connected at the half slot, the PI film with a thickness of 25 um is used as the isolation film 51 after the second cover film 3 is pasted, and then the second cover film 3 and the aluminum plate 4 are pressed and formed at one time. The excess aluminum plate 4 at the connection of the aluminum plate 4 is broken to leak the required design structure. The film surface is processed as before. The process of the heat-conducting sheet 10 is advanced, saves labor, and improves the production efficiency.

[0072] The application also discloses a heat-conducting sheet.

[0073] Referring to Figure 2The heat-conducting sheet 10 comprises a first cover film 2, a conductor layer 1, a second cover film 3 and an aluminum plate 4 which are sequentially stacked.

[0074] The second cover film 3 comprises a first surface close to the conductor layer 1 and a second surface close to the aluminum plate 4, the first surface of the second cover film 3 is coated with a first adhesive layer 31, and the second surface of the second cover film 3 is coated with a second adhesive layer 32, the first adhesive layer 31 and the second adhesive layer 32 are both thermosetting glue. The first adhesive layer 31 is used to bond the conductor layer 1 and the first surface of the second cover film 3, and the second adhesive layer 32 is used to bond the aluminum plate 4 and the second surface of the second cover film 3.

[0075] Optionally, the thickness of the first adhesive layer 31 and the second adhesive layer 32 is 30-35um.

[0076] Optionally, referring to Figure 3 and Figure 4 , the end of the aluminum plate 4 is provided with a half slot, and the half slot 41 corresponds to the pad hole of the substrate 5. An isolation film 51 is pasted on the second cover film 3 corresponding to the half slot 41 of the aluminum plate 4, the size of the isolation film 51 matches the half slot 41, and the isolation film 51 is a PI film.

[0077] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for manufacturing a thermal conductive sheet, characterized in that: The following steps are involved: Providing a conductor layer (1), the conductor layer (1) comprising a first surface and a second surface opposite to each other; Laminating a first covering film (2) on the first surface of the conductor layer (1); Providing a second covering film (3), coating a thermosetting adhesive on a first surface of the second covering film (3) to form a first adhesive layer (31), and coating a thermosetting adhesive on a second surface of the second covering film (3) to form a second adhesive layer (32); laminating a first release film on the first adhesive layer (31), and laminating a second release film on the second adhesive layer (32); The second covering film (3) is attached to the second surface of the conductor layer (1) to obtain a substrate (5), wherein the first adhesive layer (31) is located between the conductor layer (1) and the second covering film (3); the substrate (5) is placed in a laminating machine for pre-pressing to remove bubbles in the thermosetting adhesive; the pre-pressing temperature is 80°C-100°C, the pressure is 10N-20N, and the pre-pressing time is 50s-90s; Pasting the substrate (5) onto the aluminum plate (4) to form a heat conducting sheet (10); Pressing the heat conducting sheet (10) into shape using a pressing device; Before the substrate (5) is attached to the aluminum plate (4) to form the heat conducting sheet (10), the method further comprises: Tear off the second release film; Pasting an isolation film (51) on the second covering film (3) at a position corresponding to the half-broken groove (41) of the aluminum plate (4); A substrate (5) is pasted onto an aluminum plate (4) to form a heat conducting sheet (10), wherein a half-segment groove is provided at the end of the aluminum plate (4), and the half-segment groove (41) corresponds to a soldering pad hole position of the substrate (5); A gasket is provided at the half-broken groove (41) of the aluminum plate (4), and the thickness of the gasket is the same as the thickness of the aluminum plate (4).

2. A method for manufacturing a thermal conductive sheet according to claim 1, characterized in that: The isolation film (51) is a PI film.

3. The method for manufacturing a thermal conductive sheet according to claim 1, wherein: The thickness of the first adhesive layer (31) and the second adhesive layer (32) is 30um-35um.

4. The method for manufacturing a thermal conductive sheet according to claim 1, wherein: Before laminating the second covering film (3) to the second surface of the conductor layer (1) to obtain the substrate (5), the method further comprises: Tear off the first release film.

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