Heat-conducting pouring sealant and electrical equipment

Abstract

The invention relates to the technical field of electronic heat dissipation, in particular to heat-conducting pouring sealant and electrical equipment, the heat-conducting pouring sealant comprises a heat-conducting framework and heat-conducting glue, the heat-conducting framework is composed of a plurality of heat-conducting fibers, and the heat-conducting glue is filled in the heat-conducting framework. In the heat-conducting pouring sealant, the heat-conducting framework is composed of the plurality of heat-conducting fibers, the plurality of heat-conducting fibers are mutually staggered and contacted to form the heat-conducting channel, and compared with a traditional spherical powder heat-conducting filler, the heat-conducting channel formed by the heat-conducting fibers is larger in space and lower in heat resistance, so that the heat-conducting property of the heat-conducting pouring sealant is more favorably improved; besides, the space of a heat transfer channel formed by the heat-conducting fibers is larger, so that the fluidity of the heat-conducting glue during potting is better, the narrow space is easier to caulk, the hardness of the cured heat-conducting potting glue is lower, the resistance is smaller when the heat-conducting potting glue is detached (taken out of the shell), the heat-conducting potting glue is easier to detach, and the maintenance convenience of the electrical equipment can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of electronic heat dissipation, and in particular to heat-conductive potting glue and electrical equipment. Background Art

[0002] Electronic components generate heat during operation, and various environmental conditions (high humidity, salt spray, etc.) have reliability requirements. In order to solve the above problems, a thermally conductive potting glue is generally used to pot the electronic equipment as a whole. The operation method is to place the electronic components in the shell, pour the potting glue to fill the gap between the shell and the electronic components, and wait for the potting glue to solidify to form a potting layer wrapped around the outside of the electronic components. This method is simple to operate and has high reliability.

[0003] In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art: Existing potting and sealing methods often have the problem of high thermal resistance due to the low thermal conductivity of the potting compound, which makes it impossible for the heat generated by the electronic components to be quickly transferred to the surrounding potting layer structure. The heat accumulation around the electronic components will affect their working characteristics in the short term and shorten their life in the long term. In order to improve the thermal conductivity of the potting compound, some spherical powder thermal conductive fillers are often added to it. However, due to the high addition amount of such fillers (50wt%~60wt%), the hardness of the potting compound will increase after curing, which is not conducive to the disassembly of the potting compound (after curing) (disassembly between the potting compound and the electronic components). Summary of the invention

[0004] The present application proposes a thermally conductive potting compound and an electrical device, aiming to improve the thermal conductivity of the potting compound and reduce the difficulty of disassembling the cured potting compound.

[0005] In a first aspect, an embodiment of the present application provides a thermally conductive potting adhesive, wherein the thermally conductive potting adhesive comprises: A heat-conducting skeleton, composed of a plurality of heat-conducting fibers; The thermal conductive adhesive is filled in the thermal conductive skeleton.

[0006] In some embodiments, the material of the thermally conductive fiber includes one or more of aluminum nitride, silicon carbide, silicon nitride, boron nitride, and diamond.

[0007] In some embodiments, the length of the thermal conductive fiber is 10 μm to 500 μm.

[0008] In some embodiments, the diameter of the thermally conductive fiber is 5 μm to 100 μm.

[0009] In some embodiments, in the thermally conductive potting compound, the content of the thermally conductive fiber is 5 wt% to 30 wt%.

[0010] In some embodiments, a waterproof layer is disposed on the surface of the thermally conductive fiber.

[0011] In some embodiments, the thermally conductive fiber is prepared by a physical vapor transport method or a crystal growth pulling method.

[0012] In some embodiments, the Shore hardness of the thermal conductive adhesive is ≤60A.

[0013] In some embodiments, the raw materials for preparing the thermal conductive adhesive include the following components: 75 wt%~90wt% of vinyl silicone oil, 5 wt%~14wt% of hydrogen-containing silicone oil, 5 ppm~100ppm of catalyst, and 5 ppm~100ppm of inhibitor.

[0014] In some embodiments, the thermal conductivity of the thermally conductive potting glue is 4W / m·K~20W / m·K.

[0015] In a second aspect, an embodiment of the present application further proposes an electrical device, which includes a shell and electronic components, and also includes the thermal conductive potting glue as described in the first aspect, the electronic components are arranged in the shell, and the thermal conductive potting glue is filled in the gap between the electronic components and the shell.

[0016] Compared with the prior art, this technical solution has at least the following technical effects: The technical solution of the present application not only improves the thermal conductivity of the thermally conductive potting glue, but also reduces the difficulty of disassembling the thermally conductive potting glue by setting a thermally conductive skeleton for filling the thermally conductive potting glue in the thermally conductive potting glue. In the thermally conductive potting glue of the present application, the thermally conductive skeleton is composed of multiple thermally conductive fibers, and the multiple thermally conductive fibers are staggered and contacted with each other to form a heat transfer channel. Compared with the traditional spherical powder thermal conductive filler, the heat transfer channel formed by the thermally conductive fibers has a larger space and lower thermal resistance, which is more conducive to improving the thermal conductivity of the thermally conductive potting glue; in addition, the heat transfer channel formed by the thermally conductive fibers has a larger space, which will make the fluidity of the thermally conductive potting glue better during potting, and it is easier to fill the narrow space. The hardness of the thermally conductive potting glue after curing will be lower, and the resistance when disassembling the thermally conductive potting glue will be smaller, making it easier to disassemble, which can improve the convenience of maintenance of electrical equipment. DETAILED DESCRIPTION

[0017] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below.

[0018] It should be clear that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0020] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0021] The present application provides an electrical device.

[0022] In an embodiment of the present application, the electrical device includes a housing, electronic components and a thermally conductive potting compound, wherein the electronic components are arranged in the housing, and the thermally conductive potting compound is filled in a gap between the electronic components and the housing.

[0023] In the prior art, in order to improve the thermal conductivity of the thermally conductive potting compound, some spherical powder thermally conductive fillers are often added therein. However, since the amount of such fillers added is relatively high (50wt%~60wt%), the hardness of the potting compound (including the thermally conductive filler) formed by curing will increase, which is not conducive to the disassembly of the potting compound.

[0024] In order to solve the above technical problems, an embodiment of the present application proposes a thermally conductive potting glue.

[0025] In an embodiment of the present application, the thermally conductive potting glue includes a thermally conductive skeleton and thermally conductive glue; wherein the thermally conductive skeleton is composed of a plurality of thermally conductive fibers, and the thermally conductive glue is filled in the thermally conductive skeleton.

[0026] The assembly steps of the electrical equipment are as follows: electronic components are installed in a shell, with a gap between the electronic components and the shell, and then thermal conductive fibers are filled into the gap, and these thermal conductive fibers together form a thermal conductive skeleton, and then thermal conductive glue (uncured) is poured into the thermal conductive skeleton to fill the pores in the thermal conductive skeleton, and then allowed to stand. After the thermal conductive glue is completely cured, the periphery of the electronic components is coated to form a thermal conductive potting glue (including the thermal conductive skeleton and the cured thermal conductive glue).

[0027] The technical solution of the present application not only improves the thermal conductivity of the thermally conductive potting glue, but also reduces the difficulty of disassembling the thermally conductive potting glue by setting a thermally conductive skeleton for filling the thermally conductive potting glue in the thermally conductive potting glue. In the thermally conductive potting glue of the present application, the thermally conductive skeleton is composed of multiple thermally conductive fibers, and the multiple thermally conductive fibers are staggered and contacted with each other to form a heat transfer channel. Compared with the traditional spherical powder thermal conductive filler, the heat transfer channel formed by the thermally conductive fibers has a larger space and lower thermal resistance, which is more conducive to improving the thermal conductivity of the thermally conductive potting glue; in addition, the heat transfer channel formed by the thermally conductive fibers has a larger space, which will make the fluidity of the thermally conductive potting glue better during potting, and it is easier to fill the narrow space, and the hardness of the cured thermally conductive potting glue will be lower, and the resistance of the thermally conductive potting glue during disassembly (removal from the shell) will be smaller, and it will be easier to disassemble, which can improve the convenience of maintenance of electrical equipment.

[0028] In some embodiments, the length of the thermal conductive fiber is 10 μm to 500 μm, specifically 10 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm or any value therebetween. The length of the thermal conductive fiber within the above range is conducive to increasing the fluidity of the thermal conductive adhesive during potting, reducing the hardness of the thermal conductive potting adhesive, and reducing the difficulty of disassembling the thermal conductive potting adhesive; in addition, by controlling the length of the thermal conductive fiber within the above range, it is also conducive to improving the thermal conductivity of the thermal conductive potting adhesive.

[0029] In the above embodiment, the lengths of the plurality of thermal conductive fibers may be the same or different, and those skilled in the art may design them according to specific application scenarios.

[0030] In some embodiments, the diameter of the thermally conductive fiber is 5 μm to 100 μm, specifically 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm or any value therebetween. By controlling the diameter of the thermally conductive fiber within the above range, it is more conducive to improving the thermal conductivity of the thermally conductive potting glue and reducing the difficulty of disassembling the thermally conductive potting glue.

[0031] In the above embodiment, the diameters of the plurality of thermal conductive fibers may be the same or different, and those skilled in the art may design them according to specific application scenarios.

[0032] In the embodiment of the present application, the thermal conductivity of the thermally conductive potting glue is 4W / m·K~20W / m·K, and can be 4W / m·K, 6W / m·K, 8W / m·K, 10W / m·K, 12W / m·K, 14W / m·K, 16W / m·K, 18W / m·K, 20W / m·K or any value therebetween. In the embodiment of the present application, those skilled in the art can grade and optimize the mixing of thermally conductive fibers of different sizes according to specific application scenarios, so that the heat transfer channel formed by the fiber skeleton is more perfect, and the local disconnection of the channel can be avoided, which is conducive to further improving the thermal conductivity of the thermally conductive potting glue.

[0033] In the above embodiment, specifically, the thermal conductivity of the thermally conductive potting glue is 15 W / m·K to 20 W / m·K, and specifically can be 15 W / m·K, 16 W / m·K, 17 W / m·K, 18 W / m·K, 19 W / m·K, 20 W / m·K or any value therebetween.

[0034] In the embodiments of the present application, the thermally conductive fiber refers to a fiber with excellent thermal conductivity, and those skilled in the art may select the fiber according to actual conditions.

[0035] In some embodiments, the material of the thermally conductive fiber includes one or more of aluminum nitride, silicon carbide, silicon nitride, boron nitride, and diamond.

[0036] In the above embodiment, preferably, the material of the thermally conductive fiber is aluminum nitride. Compared with other materials, aluminum nitride has better thermal conductivity, and its preparation method is simple, low cost, and has broad application prospects.

[0037] Based on the above embodiments, in some embodiments, in the thermally conductive potting compound, the content of the thermally conductive fiber is 5 wt% to 30 wt%, specifically, the content of the thermally conductive fiber can be 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt% or any value therebetween. By controlling the content of the thermally conductive fiber within the above range, it is beneficial to improve the thermal conductivity of the thermally conductive potting compound and reduce the material cost of the thermally conductive potting compound.

[0038] In the embodiments of the present application, the thermally conductive fiber can be prepared by a common fiber preparation method. In some preferred embodiments, the thermally conductive fiber is prepared by a physical vapor transport method or a crystal growth pulling method; the thermally conductive fiber prepared in this way has few crystal defects, a uniform growth direction, excellent thermal conductivity, and its actual thermal conductivity is closer to its theoretical limit value of thermal conductivity.

[0039] In the embodiments of the present application, the thermally conductive fibers can be purchased from the market, or can be prepared by themselves using a preparation method commonly used in the art.

[0040] In some embodiments, a waterproof layer is provided on the surface of the thermally conductive fiber. On the one hand, the waterproof layer can improve the lipophilicity of the thermally conductive fiber and facilitate the bonding between the thermally conductive fiber and the thermally conductive adhesive; on the other hand, the waterproof layer also plays a waterproof role to prevent the thermally conductive fiber from reacting with moisture in the air, thereby reducing its thermal conductivity.

[0041] Based on the above embodiments, in some embodiments, the waterproof layer is formed by reacting a modifier such as vinyl silane, epoxy silane, stearic acid, etc. with the surface of the thermal conductive fiber. In other embodiments, the waterproof layer is a parylene coating, and the parylene coating is deposited on the surface of the thermal conductive fiber by CVD (chemical vapor deposition). Of course, the waterproof layer can also be prepared by a method.

[0042] In the embodiment of the present application, the thermally conductive adhesive can be selected from silicone thermally conductive adhesive, epoxy resin thermally conductive adhesive, polyurethane thermally conductive adhesive and other thermally conductive adhesives commonly used as potting adhesives in the art, and the embodiment of the present application does not specifically limit this.

[0043] In some embodiments, the Shore hardness of the thermal conductive adhesive is ≤60 A. Within this hardness range, it is helpful to control the hardness of the thermal conductive potting adhesive after curing within an appropriate range, thereby helping to reduce the difficulty of disassembling the thermal conductive potting adhesive.

[0044] In some embodiments, the thermally conductive adhesive is a silicone thermally conductive adhesive, and the raw materials for preparing the silicone thermally conductive adhesive include the following components: 75 wt%~90wt% of vinyl silicone oil, 5 wt%~14wt% of hydrogen-containing silicone oil, 5 ppm~100ppm of catalyst, and 5 ppm~100ppm of inhibitor.

[0045] In the above embodiment, the content of the vinyl silicone oil can be 75 wt%, 80 wt%, 85 wt%, 90 wt% or any value therebetween. The specific structural composition of the vinyl silicone oil can be selected according to actual application requirements, and this embodiment does not specifically limit this.

[0046] In the above embodiments, the content of the hydrogen-containing silicone oil may be 5 wt%, 7 wt%, 9 wt%, 11 wt%, 13 wt%, 14 wt% or any value therebetween.

[0047] In the above embodiments, those skilled in the art can select the specific structural composition of the hydrogen-containing silicone oil according to actual application requirements, and this embodiment does not specifically limit this.

[0048] In the above embodiments, the content of the catalyst may specifically be 5 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm or any value therebetween.

[0049] In the above embodiments, those skilled in the art can select the specific type of catalyst according to actual application requirements, and this embodiment does not specifically limit this.

[0050] In the above embodiments, the content of the inhibitor can specifically be 5 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm or any value therebetween.

[0051] In the above embodiments, those skilled in the art can select the specific type of inhibitor according to actual application requirements, and this embodiment does not specifically limit this.

[0052] In the embodiment of the present application, the thermally conductive adhesive can be purchased from the market, or can be prepared by oneself using a preparation method commonly used in the art.

[0053] In the embodiment of the present application, the shape of the thermally conductive potting compound is not specifically limited, and depends on the shape of the gap between the housing and the electronic components.

[0054] The present application forms a thermally conductive skeleton by adding thermally conductive fibers to a thermally conductive adhesive of low hardness (the order of addition is reversed during the potting process), thereby improving the thermal conductivity of the thermally conductive adhesive after curing; and because only a small amount of thermally conductive fibers is needed to form the thermally conductive skeleton, this makes the caulking effect during the potting of the thermally conductive adhesive better, which is beneficial to reducing the difficulty of disassembling the thermally conductive potting adhesive after curing (the difficulty of disassembling from the shell); in addition, the thermally conductive potting adhesive of the present application also has excellent properties such as good insulation, low density, and low cost, and has a wide range of applications and can be mass-produced.

[0055] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermally conductive potting adhesive, characterized in that: include: A heat-conducting skeleton, composed of a plurality of heat-conducting fibers; The thermal conductive adhesive is filled in the thermal conductive skeleton.

2. The thermally conductive potting adhesive according to claim 1, characterized in that: The material of the thermal conductive fiber includes one or more of aluminum nitride, silicon carbide, silicon nitride, boron nitride and diamond.

3. The thermally conductive potting adhesive according to claim 1, characterized in that: The length of the thermally conductive fiber is 10 μm to 500 μm; and / or, The diameter of the thermal conductive fiber is 5 μm to 100 μm.

4. The thermally conductive potting adhesive according to claim 1, characterized in that: In the thermally conductive potting glue, the content of the thermally conductive fiber is 5wt%~30wt%.

5. The thermally conductive potting adhesive according to claim 1, characterized in that: The surface of the thermally conductive fiber is provided with a waterproof layer.

6. The thermally conductive potting adhesive according to claim 1, characterized in that: The thermally conductive fiber is prepared by a physical vapor transmission method or a crystal growth pulling method.

7. The thermally conductive potting adhesive according to claim 1, characterized in that: The Shore hardness of the thermal conductive adhesive is ≤60A.

8. The thermally conductive potting adhesive according to claim 1, characterized in that: The raw materials for preparing the thermal conductive adhesive include the following components: 75wt%-90wt% of vinyl silicone oil, 5wt%-14wt% of hydrogen-containing silicone oil, 5ppm-100ppm of catalyst, and 5ppm-100ppm of inhibitor.

9. The thermally conductive potting adhesive according to any one of claims 1 to 8, characterized in that: The thermal conductivity of the thermally conductive potting glue is 4W / m·K~20W / m·K.

10. An electrical device, characterized in that: It comprises a shell and electronic components, and also comprises the thermal conductive potting glue as described in any one of claims 1-9, the electronic components are arranged in the shell, and the thermal conductive potting glue is filled in the gap between the electronic components and the shell.