Heat-conducting gasket, preparation method thereof and optical module

Abstract

A heat-conducting gasket, a preparation method thereof and an optical module belong to the technical field of heat conduction. The heat-conducting gasket comprises a heat-conducting silica gel layer and a boron nitride film layer at least attached to the surface of one side of the heat-conducting silica gel layer. The boron nitride film layer contains boron nitride and water-borne epoxy resin, and the thickness of the boron nitride film layer does not exceed 40% of the thickness of the heat conduction silica gel layer. When the heat-conducting gasket is applied to the optical module, the heat dissipation performance and the repeated plugging and unplugging use effect of the optical module can be improved.

Description

Technical Field

[0001] The present application relates to the field of heat conduction technology, and in particular to a thermally conductive gasket, a preparation method thereof, and an optical module. Background Art

[0002] With the rapid development of electronic information technology, the trend toward miniaturization of electronic products is becoming increasingly evident. However, miniaturization also brings new challenges: the heat generated by electronic products during operation cannot be effectively dissipated, which in turn damages the device, accelerates device aging, shortens its service life, and even causes malfunction.

[0003] Therefore, how to quickly conduct and dissipate heat has become a critical technical challenge that electronic products urgently need to address. In the field of thermal conductivity technology, thermal pads have attracted widespread attention for their excellent performance. Thermal pads are primarily made of silicone oil, with fillers such as metal oxides added, and processed through a specialized process. They feature low thermal resistance, high thermal conductivity, excellent insulation, and strong sealing properties. They transfer heat through the tiny gaps between the heat-generating and heat-dissipating areas, effectively dissipating heat quickly.

[0004] However, in some optical modules, the surface of conventional thermal pads is highly sticky and becomes more firmly adhered under pressure. The insertion and removal forces are very strong, which can easily damage the soft thermal pads. Summary of the Invention

[0005] In view of the above-mentioned deficiencies, the present application provides a thermally conductive gasket, a preparation method thereof, and an optical module to partially or completely improve the problem that the thermally conductive gasket of the optical module has poor performance during repeated plugging and unplugging.

[0006] This application is implemented as follows: In a first aspect, examples of the present application provide a thermally conductive gasket comprising a thermally conductive silicone layer and a boron nitride film layer attached to at least one surface of the thermally conductive silicone layer. The boron nitride film layer comprises boron nitride and a water-based epoxy resin, and the thickness of the boron nitride film layer does not exceed 40% of the thickness of the thermally conductive silicone layer.

[0007] In the above implementation process, a boron nitride film layer is provided on at least one side of the thermally conductive silicone layer. The boron nitride film layer contains boron nitride and a water-based epoxy resin. The boron nitride sheet structure has good strength, toughness, and smoothness, and the water-based epoxy resin is relatively dry and smooth. When the boron nitride and water-based epoxy resin are used to prepare the film layer, the boron nitride flakes can be compounded in the water-based epoxy resin matrix in a roughly stacked manner, resulting in the boron nitride film layer having high thermal conductivity, wear resistance, and surface smoothness. This enables the thermal gasket to exhibit good structural stability during the repeated plugging and unplugging of plug-in components such as optical modules, improves powder loss, and meets the requirements of repeated plugging and unplugging. In addition, the thickness of the boron nitride film layer does not exceed 40% of the thickness of the thermally conductive silicone layer, which makes the thermal gasket as a whole have good resilience and can effectively contact the heat sink of the electronic device, thereby reducing the contact thermal resistance and improving the overall thermal conductivity of the thermal gasket. If the boron nitride film layer is too thick and has a high hardness, the thermal pad and the heat sink will not be able to fully contact each other, which will increase the thermal resistance and affect the overall thermal conductivity of the thermal pad.

[0008] In combination with the first aspect, in an optional embodiment of the present application, the ratio of the thickness of the boron nitride film layer to the thickness of the thermally conductive silicone layer is 2% to 40%.

[0009] Optionally, the ratio of the thickness of the boron nitride film layer to the thickness of the thermal conductive silicone layer is 3% to 30%.

[0010] Optionally, the ratio of the thickness of the boron nitride film layer to the thickness of the thermal conductive silicone layer is 7% to 20%.

[0011] Optionally, the thickness of the thermally conductive silicone layer is 0.5-5 mm.

[0012] Optionally, the boron nitride film layer has a thickness of 0.1-0.2 mm.

[0013] Optionally, the thickness of the thermally conductive silicone layer is 1-3 mm, and the thickness of the boron nitride film layer is 0.15-0.2 mm.

[0014] Optionally, the particle size of the boron nitride is 30-50 μm.

[0015] In the above implementation process, the boron nitride film layer and the thermal conductive silicone layer have an appropriate thickness ratio, which can improve the surface wear resistance of the thermal conductive gasket while ensuring the resilience of the thermal conductive gasket, reduce the surface viscosity, and meet the repeated plugging and unplugging requirements and heat dissipation requirements of plug-in components such as optical modules.

[0016] In combination with the first aspect, in an optional embodiment of the present application, the mass ratio of the waterborne epoxy resin to the boron nitride is 1:(3~5).

[0017] Optionally, the mass ratio of the waterborne epoxy resin to the boron nitride is 1:(3~4).

[0018] In the above implementation process, a boron nitride film layer is arranged on one side of the thermal conductive silicone layer. The boron nitride film layer contains boron nitride and water-based epoxy resin in an appropriate mass ratio, which can make the boron nitride film layer have high thermal conductivity, wear resistance and surface smoothness, and can make the thermal conductive gasket show good structural stability during multiple plug-in and pull-out processes of plug-in components such as optical modules, improve powder loss, and meet the use requirements of repeated plug-in and pull-out.

[0019] In combination with the first aspect, in an optional embodiment of the present application, the thermally conductive silicone layer contains thermally conductive silicone and thermally conductive filler, and the mass proportion of the thermally conductive filler in the thermally conductive silicone layer does not exceed 95%.

[0020] Optionally, the mass proportion of the thermally conductive filler in the thermally conductive silicone layer is 90% to 95%.

[0021] In the above implementation process, the thermally conductive silicone layer is filled with a suitable amount of thermally conductive filler, which can improve the thermal conductivity of the thermally conductive silicone layer while ensuring that the thermally conductive silicone layer has good resilience, thereby meeting the heat transfer requirements between the optical module plug-in and the heat sink.

[0022] In combination with the first aspect, in an optional embodiment of the present application, the thermal conductivity of the thermally conductive filler is not less than 30 W / m·K.

[0023] Optionally, the thermally conductive filler includes at least one of nitride ceramics, oxide ceramics, carbide ceramics or diamond.

[0024] Optionally, the thermally conductive filler includes at least one of aluminum oxide, magnesium oxide, silicon oxide, beryllium oxide, boron carbide, silicon carbide, silicon nitride, aluminum nitride or diamond.

[0025] In the above implementation process, filling the thermal conductive filler with high thermal conductivity into the thermal conductive silicone layer can further improve the thermal conductivity of the thermal conductive gasket.

[0026] In combination with the first aspect, in an optional embodiment of the present application, the thermally conductive filler includes diamond with a particle size of 100~120um, aluminum nitride with a particle size of 80~100um, and aluminum oxide with a particle size of 10~20um, and the mass ratio of the diamond: the aluminum oxide: the aluminum nitride is (1~5): (1~5): (1~5).

[0027] Optionally, the mass ratio of aluminum nitride:aluminum oxide:diamond is 1:1:1.

[0028] In the above implementation process, the above-mentioned aluminum nitride, aluminum oxide and diamond of different particle sizes are added to the thermally conductive silicone layer in appropriate proportions. This not only can adjust the thermal conduction path inside the thermally conductive silicone layer by matching high, medium and low particle sizes, so that the thermally conductive silicone layer has a certain resilience and good thermal conductivity, but also can utilize the combination of thermally conductive materials with different characteristics to improve the insulation and electrochemical stability of the thermally conductive silicone layer and reduce costs.

[0029] In conjunction with the first aspect, in an optional embodiment of the present application, the thermally conductive silicone is mainly formed by curing a two-component adhesive, which includes at least one of vinyl silicone oil and polyether-modified silicone oil.

[0030] Optionally, the two-component adhesive further comprises a vulcanization inhibitor, a curing agent and a coupling agent.

[0031] Optionally, the boron nitride film layer is bonded to one side surface of the thermally conductive silicone layer through a silicone treatment agent.

[0032] In the above implementation process, a two-component adhesive containing the above-mentioned vinyl silicone oil or polyether modified silicone oil, vulcanization inhibitor, curing agent and coupling agent is cured to form a carrier of thermal conductive filler, which can carry an appropriate filling amount of thermal conductive powder, maintain good resilience, and also has good high temperature resistance and anti-aging properties, thereby further extending the service life of the thermal gasket.

[0033] In a second aspect, an example of the present application provides a method for preparing a thermally conductive gasket, comprising: Boron nitride powder and water-based epoxy resin are dispersed in water to obtain a dispersion, which is then applied to the mold surface and dried and solidified to obtain a boron nitride film layer.

[0034] The boron nitride film layer is peeled off from the mold surface and attached to at least one side of the thermally conductive silicone layer to obtain a thermally conductive gasket. The thickness of the boron nitride film layer does not exceed 40% of the thickness of the thermally conductive silicone layer.

[0035] In the above-mentioned implementation process, boron nitride powder and water-based epoxy resin are dispersed in water to form a dispersion, and after the dispersion is applied, the water-based epoxy resin is cured to obtain a boron nitride film layer containing boron nitride and water-based epoxy resin. The boron nitride film layer has good wear resistance and surface smoothness, and also has good thermal conductivity. After a boron nitride film layer of appropriate thickness is attached to at least one side of the thermal conductive silicone layer to form a thermal gasket, the thermal gasket can have good thermal conductivity and resilience, and one side of the thermal gasket also has good wear resistance and low surface viscosity. After the side of the above-mentioned thermal gasket facing away from the boron nitride film layer is adhered to the surface of a plug-in component such as an optical module, the repeated plug-in service life and heat dissipation of the plug-in component such as the optical module can be improved.

[0036] In combination with the second aspect, in an optional embodiment of the present application, the attachment method includes: bonding the boron nitride film layer to one side of the thermally conductive silicone layer through a silicone treatment agent, and curing it at 40-60° C. for 30-60 minutes.

[0037] Optionally, the solid content of the waterborne epoxy resin is 60% to 70%.

[0038] Optionally, in the boron nitride film layer, the mass ratio of boron nitride to waterborne epoxy resin is (3-5):1.

[0039] Optionally, in the boron nitride film layer, the mass ratio of boron nitride to waterborne epoxy resin is (3~4):1.

[0040] Optionally, the thickness of the thermally conductive silicone layer is 0.5-5 mm, and the thickness of the boron nitride film layer is 0.1-0.2 mm.

[0041] In this implementation, the boron nitride film is bonded to one side of the thermally conductive silicone layer using a silicone treatment agent, improving bonding stability and reducing the thermal resistance of the thermal pad. Using a water-based epoxy resin with a solids content of 60% to 70% imparts excellent hardness and toughness to the boron nitride film, further enhancing wear resistance.

[0042] In a third aspect, an embodiment of the present application provides an optical module, including an optical module body and a thermally conductive gasket, wherein the optical module body is bonded to a side of the thermally conductive silicone layer facing away from the boron nitride film layer.

[0043] In the above-mentioned implementation process, the thermal conductive gasket provided in the first aspect of the present application is arranged on the surface of the optical module body, and a boron nitride film layer of appropriate thickness is arranged on the side of the thermal conductive gasket facing away from the optical module. The boron nitride film layer contains an appropriate content of boron nitride and water-based epoxy resin, which can improve the wear resistance of the thermal conductive gasket while ensuring the resilience and thermal conductivity of the thermal conductive gasket, thereby improving the stability of the optical module during the plugging and unplugging process and increasing the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0045] Figure 1 A schematic diagram of the structure of the thermally conductive gasket provided in an embodiment of the present application; Figure 2 Schematic diagram of the preparation process of the thermally conductive gasket provided in an embodiment of the present application.

[0046] Icon: 100-thermal gasket; 101-thermal silicone layer; 102-boron nitride film layer. DETAILED DESCRIPTION

[0047] The embodiments of the present application will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0048] An optical module is an integrated module that converts optical signals into electrical signals and / or electrical signals into optical signals. It plays a vital role in fiber optic communications. Optical modules generate a significant amount of heat during operation. The lasers used to generate or receive optical signals within an optical module have relatively strict temperature requirements. To ensure normal optical communication, this heat must be dissipated promptly. Typically, a thermal pad is placed on the surface of the optical module, in contact with a heat sink, to transfer heat from the module to the heat sink for dissipation. Currently, these thermal pads are typically silicone.

[0049] However, module maintenance or expansion often requires installing and removing modules from electronic product ports (i.e., plugging and unplugging). To ensure proper module functionality, a certain amount of force must be applied during this process. Conventional thermal pads have a strong adhesive surface, which becomes even more firmly adhered under pressure. This high insertion and removal force can easily damage the soft thermal pad.

[0050] Therefore, to reduce the surface stickiness of the thermal pad, the inventors tried applying a single-sided adhesive treatment to the surface of the silicone thermal pad, hoping to improve its performance. However, the inventors found that even with the adhesive treatment, the thermal pad would gradually release oil and become sticky after prolonged pressure application. Furthermore, the pad would easily wear and shed powder during insertion and removal, contaminating the circuit board.

[0051] The inventors further attempted to prepare a polyimide film on the surface of the thermally conductive gasket. However, the polyimide film has low thermal conductivity and has a significant impact on the thermal conductivity of the thermally conductive gasket, making it difficult to apply to some high-power optical modules.

[0052] Based on this, the present application provides a thermally conductive gasket, a preparation method thereof, and an optical module to improve the problem of poor performance of the thermally conductive gasket during the plugging and unplugging of the optical module.

[0053] See also Figure 1 The present invention provides a thermally conductive gasket 100 comprising a thermally conductive silicone layer 101 and a boron nitride film layer 102 attached to at least one surface of the thermally conductive silicone layer 101. The boron nitride film layer 102 comprises boron nitride and a water-based epoxy resin, and the thickness of the boron nitride film layer 102 does not exceed 40% of the thickness of the thermally conductive silicone layer 101.

[0054] A boron nitride film layer 102 is disposed on one side of the thermally conductive silicone layer 101. This layer contains boron nitride and water-based epoxy resin, resulting in high thermal conductivity and wear resistance. Its smooth surface ensures good structural stability and reduces powder shedding during repeated plugging and unplugging of the thermal pad 100. The water-based epoxy resin, combined with the boron nitride, releases less oil under pressure than silicone, mitigating the stickiness of the thermal pad 100 during use and further extending its service life to meet the repeated plugging and unplugging requirements of optical modules.

[0055] Furthermore, the thickness of the boron nitride film layer 102 does not exceed 40% of the thickness of the thermally conductive silicone layer 101, so that the thermal gasket 100 as a whole has good resilience, can effectively contact the heat sink in the electronic device, reduce the contact thermal resistance, and improve the heat dissipation of the optical module. If the boron nitride film layer is too thin, the wear resistance is poor, and the insertion and removal force of the optical module during insertion and removal is large, which can easily damage the thermal gasket and shorten its service life. If the boron nitride film layer is too thick and hard, the thermal gasket has poor resilience, which can lead to insufficient contact between the thermal gasket and the device, increase the thermal resistance, and affect the heat dissipation of the optical module.

[0056] It can be understood that the thermally conductive gasket 100 includes a thermally conductive silicone layer 101 and a boron nitride film layer 102 attached to at least one surface of the thermally conductive silicone layer 101, which means that the boron nitride film layer 102 can be attached to only one surface of the thermally conductive silicone layer 101, or the boron nitride film layer 102 can be attached to both surfaces of the thermally conductive silicone layer 101, or the boron nitride film layer 102 can be attached to more surfaces of the thermally conductive silicone layer 101, and this application does not impose any restrictions.

[0057] In some real-time examples, when the thermally conductive gasket 100 provided in the embodiment of the present application needs to be applied to plug-in components such as optical modules, the embodiment of the present application can only set the boron nitride film layer 102 on one side of the thermally conductive silicone layer 101, and the other side of the thermally conductive silicone layer 101 has good viscosity and can be firmly adhered to the surface of the optical module body.

[0058] This application does not limit the specific type of thermally conductive silicone layer 101; it can be selected based on conventional thermally conductive gaskets in the art. In some embodiments, thermally conductive silicone layer 101 comprises thermally conductive silicone and a thermally conductive filler. The thermally conductive filler is filled in the thermally conductive silicone, and the thermally conductive filler has a high thermal conductivity coefficient, which can further improve the thermal conductivity of thermally conductive silicone layer 101.

[0059] The present application does not limit the specific type of thermally conductive filler. In some embodiments, a thermally conductive filler with a thermal conductivity coefficient of not less than 30 W / m·K can be selected. The higher the thermal conductivity coefficient of the thermally conductive filler, the more conducive it is to improving the overall thermal conductivity of the thermally conductive gasket 100.

[0060] As an example, the thermally conductive filler may be selected from at least one of nitride ceramics, oxide ceramics, carbide ceramics, or diamond. For example, the thermally conductive filler may be selected from at least one of aluminum oxide, magnesium oxide, silicon oxide, beryllium oxide, boron carbide, silicon carbide, silicon nitride, aluminum nitride, or diamond.

[0061] To further improve the thermal conductivity of thermally conductive gasket 100, in some embodiments, the thermally conductive filler includes diamond with a particle size of 100-120 μm, aluminum nitride with a particle size of 80-100 μm, and aluminum oxide with a particle size of 10-20 μm, with a mass ratio of diamond:aluminum oxide:aluminum nitride of (1-5):(1-5):(1-5). Adding appropriate proportions of these different particle sizes of diamond, aluminum nitride, and aluminum oxide to thermally conductive silicone layer 101 not only adjusts the thermal conduction path within thermally conductive silicone layer 101 by combining high, medium, and low particle sizes, ensuring that thermally conductive silicone layer 101 has both a certain degree of resilience and good thermal conductivity, but also utilizes the combination of thermally conductive materials with different properties to improve the insulation and electrochemical stability of thermally conductive silicone layer 101, thereby reducing costs.

[0062] As an example, the particle size of diamond can be one of 100 μm, 105 μm, 110 μm, 115 μm, or 120 μm, or any range between two thereof. As an example, the particle size of aluminum nitride can be one of 80 μm, 85 μm, 90 μm, 95 μm, or 100 μm, or any range between two thereof. As an example, the particle size of aluminum oxide can be one of 10 μm, 15 μm, or 20 μm, or any range between two thereof. In this application, particle size refers to average particle size.

[0063] Furthermore, the mass ratio of diamond to aluminum nitride may be one of 1:1, 1:2, 1:3, 1:4, 1:5, 2:1, 3:1, 4:1, 5:1, or a range between any two thereof. Furthermore, the mass ratio of diamond to aluminum oxide may be one of 1:1, 1:2, 1:3, 1:4, 1:5, 2:1, 3:1, 4:1, 5:1, or a range between any two thereof.

[0064] Furthermore, in some embodiments, the mass ratio of diamond:aluminum nitride:aluminum oxide may be 1:1:1.

[0065] Furthermore, the embodiments of the present application do not limit the specific filling amount of the thermally conductive filler. In some embodiments, the thermally conductive filler accounts for no more than 95% by weight of the thermally conductive silicone layer 101. A suitable filling amount of the thermally conductive filler in the thermally conductive silicone layer 101 can provide the thermally conductive silicone layer 101 with good resilience.

[0066] Furthermore, in some embodiments, the mass proportion of the thermally conductive filler in the thermally conductive silicone layer 101 is 90% to 95%, which can take into account both the thermal conductivity and resilience of the thermally conductive gasket 100 .

[0067] As an example, the mass proportion of the thermally conductive filler in the thermally conductive silicone layer 101 may be 90%, 91%, 92%, 93%, 94% or 95%, or a range between any two of them.

[0068] The present application does not limit the specific type of thermally conductive silicone, and can be selected according to conventional thermally conductive silicone materials in the art. In some embodiments, the thermally conductive silicone can be formed by curing a two-component adhesive containing vinyl silicone oil or polyether modified silicone oil.

[0069] Furthermore, the two-component adhesive further includes a vulcanization inhibitor, a curing agent and a coupling agent.

[0070] Furthermore, the present application does not limit the specific shape and thickness of the thermally conductive silicone layer 101 , and a corresponding selection can be made according to the needs of the optical module.

[0071] In some embodiments, the thermally conductive silicone layer 101 may be a quadrilateral plate-shaped structure.

[0072] In some embodiments, the thickness of the thermally conductive silicone layer 101 can be 0.5-5 mm. As an example, the thickness of the thermally conductive silicone layer 101 can be in the range of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 0.5 mm, or any two thereof.

[0073] Furthermore, the thickness of the thermally conductive silicone layer 101 may be 1-3 mm.

[0074] The present application does not limit the specific mass ratio of boron nitride and waterborne epoxy resin in the boron nitride film layer 102. In some embodiments, the mass ratio of waterborne epoxy resin:boron nitride is within the range of 1:(3-5) and is selected accordingly as needed.

[0075] If the boron nitride content in the boron nitride film 102 is too high, the boron nitride will not be properly filled into the water-based epoxy resin matrix, and powder will easily fall off during insertion and removal, which can damage the circuit and affect the use of the optical module. If the boron nitride content is too low, the strength and toughness of the boron nitride film 102 will be poor, affecting wear resistance.

[0076] As an example, the mass ratio of the waterborne epoxy resin to the boron nitride may be 1:3, 1:3.5, 1:4, 1:4.5, or 1:5, or a range between any two of them.

[0077] Furthermore, the present application does not limit the type and particle size of boron nitride. In some embodiments, hexagonal boron nitride can be selected. In some embodiments, the particle size of boron nitride can be 30~50um. Although the larger the particle size of boron nitride, the fewer grain boundaries, the lower the grain boundary thermal resistance, and the thermal conductivity can be improved, the larger the boron nitride grains, the greater the brittleness, and it is easy to break and shed powder during the friction process, and the larger the grains, the worse the surface smoothness. Therefore, adding boron nitride of appropriate particle size can further take into account the wear resistance, thermal conductivity and surface viscosity of the boron nitride film layer 102.

[0078] As an example, the particle size of the boron nitride may be one of 30 um, 35 um, 40 um, 45 um or 50 um, or a range between any two of them.

[0079] The thickness of the boron nitride film layer 102 does not exceed 40% of the thickness of the thermally conductive silicone layer 101, ensuring that the thermally conductive gasket 100 as a whole has good resilience, ensuring good contact with the electronic device, reducing contact thermal resistance, and improving heat dissipation. This application does not limit the specific thickness ratio of the boron nitride film layer 102 to the thermally conductive silicone layer 101. In some embodiments, the ratio of the thickness of the boron nitride film layer 102 to the thickness of the thermally conductive silicone layer 101 is between 2% and 40%.

[0080] Furthermore, the ratio of the thickness of the boron nitride film layer 102 to the thickness of the thermally conductive silicone layer 101 may be 3% to 30%.

[0081] Furthermore, the ratio of the thickness of the boron nitride film layer 102 to the thickness of the thermally conductive silicone layer 101 may be 7% to 20%.

[0082] Furthermore, when the thickness of the thermally conductive silicone layer 101 is 0.5-5 mm, the thickness of the boron nitride film layer 102 may be 0.1-0.2 mm.

[0083] Furthermore, when the thickness of the thermally conductive silicone layer 101 is 1-3 mm, the thickness of the boron nitride film layer 102 can be 0.15-0.2 mm, which can meet the thermal conductivity and pluggable requirements of the optical module.

[0084] It is understood that in order to adhere the boron nitride film layer 102 to at least one surface of the thermally conductive silicone layer 101, a bonding layer (not shown in the figure) is inevitably present between the boron nitride film layer 102 and the thermally conductive silicone layer 101. In some embodiments, this bonding layer can be formed by bonding the thermally conductive silicone layer 101 and the boron nitride film layer 102 using a silicone treatment agent. Bonding the thermally conductive silicone layer 101 and the boron nitride film layer 102 using a silicone treatment agent can improve bonding strength and reduce thermal resistance at the bonding interface.

[0085] Furthermore, the present invention also provides a method for preparing the thermally conductive pad. Figure 2 ,include: S1. Obtain a thermally conductive silicone layer.

[0086] S2. Obtaining a boron nitride film: Disperse boron nitride powder and water-based epoxy resin in water to obtain a dispersion; apply the dispersion to the mold surface and dry and solidify. The thickness of the boron nitride film should not exceed 40% of the thickness of the thermally conductive silicone layer.

[0087] S3. Composite: peeling the boron nitride film layer from the mold surface and attaching it to at least one side of the thermal conductive silicone layer to obtain a thermal conductive gasket.

[0088] In step S1, the present application does not limit how to obtain the thermally conductive silicone layer, and the thermally conductive silicone layer can be purchased from conventional thermally conductive gaskets commercially available in the art.

[0089] Alternatively, in some embodiments, the present application also provides a method for preparing a thermally conductive silicone layer, comprising: uniformly mixing thermally conductive powder and AB glue; rolling the mixture at 60-80°C to a thickness of 0.5-5 mm; vulcanizing the rolled material at 120-150°C for 10-20 minutes; and cooling the vulcanized material to room temperature.

[0090] The present application does not limit the specific type of thermally conductive powder. In some embodiments, at least one of nitride ceramics, oxide ceramics, carbide ceramics, or diamond with a thermal conductivity of not less than 30 W / m·k may be selected.

[0091] Furthermore, the mass proportion of the thermally conductive filler in the thermally conductive silicone layer does not exceed 95%.

[0092] Furthermore, the AB glue may be a two-component adhesive containing vinyl silicone oil or polyether-modified silicone oil.

[0093] In step S2, the solid content of the waterborne epoxy resin can be 60% to 70%. It will be understood that the solid content of the waterborne epoxy resin refers to the content of the curable components of the epoxy resin. As an example, the solid content of the waterborne epoxy resin can be 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% or 70%, or a range between any two of them.

[0094] Furthermore, the dispersion liquid may be applied to the mold surface by a doctor blade method. After coating, the coated electrode may be placed at 120-150° C. for drying and curing for 20-30 minutes.

[0095] In step S3, after the boron nitride film layer is peeled off from the mold surface, the boron nitride film layer can be bonded to one side of the thermal conductive silicone layer using a silicone treatment agent, and the bonded gasket is placed at 40-60°C for curing for 30-60 minutes to obtain a thermal conductive gasket.

[0096] In some embodiments, in the boron nitride film layer, the mass ratio of boron nitride to the cured waterborne epoxy resin is (3-5):1.

[0097] Furthermore, in the boron nitride film layer, the mass ratio of boron nitride to the cured waterborne epoxy resin is (3~4):1.

[0098] Furthermore, before the boron nitride film layer is bonded to one side surface of the thermally conductive silicone layer using the silicone treatment agent, the thermally conductive silicone layer may be ultrasonically cleaned and dried.

[0099] When preparing the thermally conductive gasket, a boron nitride film layer with a thickness of 0.1 to 0.2 mm can be adhered to one side surface of a thermally conductive silicone layer with a thickness of 0.5 to 5 mm.

[0100] Furthermore, embodiments of the present application provide an optical module. The optical module includes an optical module body and a thermally conductive gasket. The optical module body is bonded to the side of the thermally conductive silicone layer facing away from the boron nitride film layer. This application does not limit the specific type of optical module; it can be selected based on conventional optical modules in the art.

[0101] Furthermore, embodiments of the present application provide an electronic device comprising an optical module, a circuit board, and a heat sink. A slot is formed between the circuit board and the heat sink, into which the optical module can be selectively inserted. When the optical module is inserted into the slot, one side of the optical module connects to the circuit board, while the boron nitride film layer on the other side of the optical module contacts the heat sink. During operation, heat generated by the optical module body is conducted to the heat sink via the thermal pad, where it is dissipated.

[0102] During the insertion and removal of the optical module, the boron nitride film of the thermal pad contacts the heat sink at the insertion slot. Due to the boron nitride film's excellent wear resistance and low surface viscosity, it offers minimal resistance during insertion and removal, making the thermal pad less susceptible to damage. The boron nitride film's optimal thickness and content ensure excellent resilience, ensuring good contact with the heat sink, reducing contact thermal resistance and improving heat dissipation.

[0103] The thermal conductive gasket of the present application is further described in detail below with reference to the embodiments.

[0104] Example 1 Example 1 provides a thermally conductive pad, and the preparation method is as follows: (1) Preparation of thermally conductive silicone layer: Diamond with a particle size of 100 μm (purchased from Henan Feimeng Diamond Co., Ltd.), spherical aluminum nitride with a particle size of 80 μm (purchased from Chengdu Xuci New Materials Co., Ltd.) and spherical aluminum oxide with a particle size of 20 μm (purchased from Dengka brand agent) were mixed in a mass ratio of 1:1:1, AB glue (purchased from Guangzhou Chensi New Materials Technology Co., Ltd.) was added, and stirred evenly to obtain a mixture. The mixture was rolled at 70°C to a thickness of 2 mm to obtain a rolled material. The rolled material was placed at 130°C for vulcanization for 20 minutes to obtain a vulcanized material. The vulcanized material was cooled to room temperature at room temperature to obtain a thermally conductive silicone layer.

[0105] (2) Preparation of Boron Nitride Film: Hexagonal boron nitride with a particle size of 30 μm (purchased from a 3M brand agent) and a water-based epoxy resin with a solid content of 70% (purchased from Guangzhou Bangtai New Materials Co., Ltd.) were dispersed in water and stirred evenly to obtain a dispersion. The dispersion was applied to the mold surface, and the coated mold was dried and cured at 150°C for 20 minutes to obtain a boron nitride film layer with a thickness of 0.15 mm. In the boron nitride film layer, the mass ratio of the cured water-based epoxy resin to the boron nitride was 1:4.

[0106] (3) Compounding: The thermal conductive silicone layer obtained in step (1) is cleaned by ultrasonic wave and then blown dry. The boron nitride film layer obtained in step (2) is bonded to one side surface of the thermal conductive silicone layer by using a silicone treatment agent (purchased from Shin-Etsu Chemical brand agent). The bonded assembly is cured at 50°C for 30 minutes to obtain a thermal conductive gasket.

[0107] Example 2 Example 2 provides a thermally conductive gasket, which differs from Example 1 in that: in step (2), the mass ratio of the epoxy resin to the boron nitride water is 1:3.

[0108] Example 3 Example 3 provides a thermally conductive gasket, which differs from Example 1 in that: in step (2), the mass ratio of water-based epoxy resin to boron nitride is 1:6.

[0109] Comparative Example 1 Comparative Example 1 provides a thermally conductive gasket, which differs from Example 1 in that step (2) and step (3) are not performed. That is, the thermally conductive gasket is a thermally conductive silicone layer.

[0110] Comparative Example 2 Comparative Example 2 provides a thermally conductive gasket, which differs from Example 1 in that step (2) is not performed. In step (3), the surface of the thermally conductive silicone layer prepared in step (1) is directly coated with a silicone treatment agent having the same content as in Example 1, and the mixture is cured at 50°C for 30 minutes to obtain a thermally conductive gasket.

[0111] Comparative Example 3 Comparative Example 3 provides a thermally conductive gasket, which differs from Example 1 in that a PI film with a thickness of 25 μm (purchased from Dongguan Yierda Electronic Technology Co., Ltd.) is used to replace the boron nitride film layer in step (2).

[0112] Comparative Example 4 Comparative Example 4 provides a thermally conductive gasket, which differs from Example 1 in that a 0.15 mm thick composite film layer of silicon carbide and silica gel (the mass ratio of silica gel to silicon carbide is 1:4) is used to replace the boron nitride film layer in step (2). Some process parameters of the present embodiment and comparative example are shown in Table 1.

[0113] Table 1

[0114] Test Case The thermal conductivity and plug-in / out performance of the thermally conductive gaskets provided in Examples 1-3 and Comparative Examples 1-4 were tested. The thermal conductivity coefficient was tested according to the international standard GB / T 39862-2021, and the thermal resistance was tested using a Taiwan Ruiling thermal tester. The thermally conductive gaskets were placed in the optical module equipment, and the optical module was repeatedly plugged in and out to test the plug-in / out performance. The test results are shown in Table 2.

[0115] Table 2

[0116] Result analysis: It can be seen from Table 2 that the thermally conductive gasket provided in the embodiment of the present application has good thermal conductivity and also has good repeated plugging and unplugging performance.

[0117] By comparing Example 1 and Comparative Example 2, it can be seen that by providing a boron nitride film layer of suitable thickness and mass ratio on one side surface of the thermally conductive silicone layer, the repeated plugging and unplugging effect of the thermally conductive gasket can be improved without substantially reducing the thermal conductivity and substantially increasing the internal resistance, and the thermally conductive gasket can be repeatedly plugged and unplugged for multiple times.

[0118] Moreover, by comparing Example 1 and Comparative Example 2, it can be seen that although coating the surface of the thermally conductive silicone layer with a silicone surface treatment agent can improve the number of plugging and unplugging times to a certain extent, after long-term use, after 5 plugging and unplugging times, the thermally conductive gasket is damaged, and the plugging and unplugging effect is poor.

[0119] Comparing Example 1 and Comparative Example 3, it can be seen that while the PI film bonded to the surface of the thermally conductive silicone layer in Comparative Example 3 improves the plug-and-unplug performance of the thermal pad, the PI film significantly reduces the thermal conductivity of the thermal pad and increases thermal resistance. This can affect heat dissipation when used in optical modules.

[0120] By comparing Example 1 and Comparative Example 4, it can be seen that compared with the method of using silicon carbide and silicone in Comparative Example 4, Example 1 of the present application uses boron nitride and water-based epoxy resin to improve the thermal conductivity coefficient and repeated plugging and unplugging effect of the thermal gasket at the same time.

[0121] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A thermally conductive gasket, characterized in that: include: A thermally conductive silicone layer and a boron nitride film layer attached to at least one surface of the thermally conductive silicone layer; the boron nitride film layer contains boron nitride and water-based epoxy resin, and the thickness of the boron nitride film layer does not exceed 40% of the thickness of the thermally conductive silicone layer.

2. The thermally conductive pad according to claim 1, wherein: The ratio of the thickness of the boron nitride film layer to the thickness of the thermal conductive silicone layer is 2% to 40%; Optionally, the ratio of the thickness of the boron nitride film layer to the thickness of the thermal conductive silicone layer is 3% to 30%; Optionally, the ratio of the thickness of the boron nitride film layer to the thickness of the thermally conductive silicone layer is 7% to 20%; Optionally, the thickness of the thermally conductive silicone layer is 0.5-5 mm; Optionally, the thickness of the boron nitride film layer is 0.1-0.2 mm; Optionally, the thickness of the thermally conductive silicone layer is 1-3 mm, and the thickness of the boron nitride film layer is 0.15-0.2 mm; Optionally, the particle size of the boron nitride is 30-50 μm.

3. The thermally conductive pad according to claim 1 or 2, characterized in that: The mass ratio of the waterborne epoxy resin to the boron nitride is 1:(3-5); Optionally, the mass ratio of the waterborne epoxy resin to the boron nitride is 1:(3-4).

4. The thermally conductive pad according to claim 1, wherein: The thermally conductive silicone layer contains thermally conductive silicone and thermally conductive filler, and the thermally conductive filler accounts for no more than 95% of the mass of the thermally conductive silicone layer; Optionally, the mass proportion of the thermally conductive filler in the thermally conductive silicone layer is 90% to 95%.

5. The thermally conductive pad according to claim 4, characterized in that: The thermal conductivity of the thermally conductive filler is not less than 30W / m·k; Optionally, the thermally conductive filler includes at least one of nitride ceramics, oxide ceramics, carbide ceramics or diamond; Optionally, the thermally conductive filler includes at least one of aluminum oxide, magnesium oxide, silicon oxide, beryllium oxide, boron carbide, silicon carbide, silicon nitride, aluminum nitride or diamond.

6. The thermally conductive pad according to claim 4, characterized in that: The thermal conductive filler comprises diamond with a particle size of 100-120 μm, aluminum nitride with a particle size of 80-100 μm, and aluminum oxide with a particle size of 10-20 μm, wherein the mass ratio of the diamond: the aluminum oxide: the aluminum nitride is (1-5): (1-5): (1-5); Optionally, the mass ratio of the aluminum nitride: the aluminum oxide: the diamond is 1:1:

1.

7. The thermally conductive pad according to any one of claims 4 to 6, characterized in that: The thermally conductive silicone is mainly formed by curing a two-component adhesive, wherein the two-component adhesive includes at least one of vinyl silicone oil and polyether modified silicone oil; Optionally, the two-component adhesive further comprises a vulcanization inhibitor, a curing agent and a coupling agent; Optionally, the boron nitride film layer is bonded to one side surface of the thermally conductive silicone layer through a silicone treatment agent.

8. A method for preparing a thermally conductive gasket, characterized in that: include: dispersing boron nitride powder and waterborne epoxy resin in water to obtain a dispersion; Applying the dispersion on the surface of the mold, drying and solidifying it to obtain a boron nitride film layer; The boron nitride film layer is peeled off from the mold surface and attached to at least one side of the thermally conductive silicone layer to obtain the thermally conductive gasket; the thickness of the boron nitride film layer does not exceed 40% of the thickness of the thermally conductive silicone layer.

9. The preparation method according to claim 8, characterized in that The attaching method includes: Adhere the boron nitride film layer to one side of the thermal conductive silicone layer through a silicone treatment agent, and cure at 40-60° C. for 30-60 minutes; Optionally, the solid content of the waterborne epoxy resin is 60% to 70%; Optionally, in the boron nitride film layer, the mass ratio of the boron nitride to the waterborne epoxy resin is (3-5):1; Optionally, in the boron nitride film layer, the mass ratio of the boron nitride to the waterborne epoxy resin is (3-4):1; Optionally, the thickness of the thermally conductive silicone layer is 0.5-5 mm, and the thickness of the boron nitride film layer is 0.1-0.2 mm.

10. An optical module, characterized in that: The optical module comprises an optical module body and the thermally conductive gasket according to any one of claims 1 to 7, wherein the optical module body is bonded to a side of the thermally conductive silicone layer facing away from the boron nitride film layer.

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