Packaging structure, packaging method, heat dissipation structure processing method and electronic equipment

Abstract

The embodiment of the invention provides a packaging structure and method, a heat dissipation structure processing method and electronic equipment. The packaging structure comprises a packaging substrate; the chip is connected with the packaging substrate, and the components are located on the periphery of the chip. The heat dissipation structure is connected with the packaging substrate and the chip, and the heat dissipation structure and the chip are connected through a thermal interface material layer formed by welding thermal interface metal materials; the protective coating is used for protecting the surface of the component and is at least used for preventing metal sputtering generated by welding and melting of the thermal interface metal material from damaging the component; wherein the heat dissipation structure comprises a slotting structure which is used for reserving a thermal expansion space for the protective coating so as to prevent the protective coating from being in contact with the heat dissipation structure after thermal expansion. According to the packaging structure provided by the embodiment of the invention, the damage of metal sputtering to the component can be avoided, the component is protected, and the packaging effect is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor packaging technology, and specifically to a packaging structure, a packaging method, a heat dissipation structure processing method, and an electronic device. Background Art

[0002] In order to meet the heat dissipation requirements of the chip, during the chip packaging process, the chip, thermal interface metal material and heat dissipation structure can be welded together through a welding process to conduct heat to the chip through the heat dissipation structure. However, during the welding process, high temperatures will cause the thermal interface metal material to melt, resulting in metal sputtering, which will damage the components in the packaging structure and affect the chip packaging effect. Summary of the invention

[0003] In view of this, the embodiments of the present application provide a packaging structure, a packaging method, a heat dissipation structure processing method and an electronic device, which can prevent metal sputtering from damaging components and protect components, while increasing the process window and improving the packaging effect.

[0004] To achieve the above objectives, the embodiments of the present application provide the following technical solutions.

[0005] In a first aspect, an embodiment of the present application provides a packaging structure, including:

[0006] Package substrate;

[0007] A chip connected to the packaging substrate, and components located around the chip;

[0008] A heat dissipation structure connecting the package substrate and the chip, wherein the heat dissipation structure and the chip are connected through a thermal interface material layer formed by welding a thermal interface metal material;

[0009] A protective coating for protecting the surface of components, the protective coating is at least used to prevent the metal sputtering generated by the melting of the thermal interface metal material from damaging the components;

[0010] Wherein, the heat dissipation structure includes a slotted structure, which is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0011] Optionally, the protective coating completely wraps the surface of the component, and the protective coating includes a top coating and a bottom filling layer, the top coating covers the top surface and side surfaces of the component, and the bottom filling layer covers at least the bottom surface of the component.

[0012] Optionally, the bottom filling layer also wraps the bottom solder joints on the bottom surface of the components, and the bottom solder joints are used to connect the components to the packaging substrate;

[0013] Among them, the bottom filling layer material forming the bottom filling layer is fluid during the process of forming the bottom filling layer and before solidification. The bottom filling layer material fills the gap between the components and the packaging substrate through capillary action from the common channel area between the bottoms of the multiple components to wrap the bottom solder joints of the components.

[0014] Optionally, the slot size of the slot structure is designed to reserve thermal expansion space for the protective coating in an expansion direction of the protective coating corresponding to the slot size.

[0015] Optionally, the slot dimensions include slot width and slot depth;

[0016] The slot width of the slot structure is designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slot width of the protective coating;

[0017] The groove depth of the groove structure is designed to reserve thermal expansion space for the protective coating in the expansion direction of the protective coating corresponding to the groove depth.

[0018] Optionally, the slotted structure is a top slotted structure of the heat dissipation structure, and the slotted width of the top slotted structure is designed to reserve thermal expansion space for the protective coating in the horizontal expansion direction of the protective coating;

[0019] The groove depth of the top groove structure is designed to reserve thermal expansion space for the protective coating in the vertical expansion direction of the protective coating.

[0020] Optionally, the width of the top groove structure is not less than the width of the protective coating.

[0021] Optionally, it further comprises: a barrier layer surrounding the periphery of the component, the barrier layer being used to prevent the bottom filling layer material on the bottom surface of the component from overflowing;

[0022] Wherein, the height of the barrier layer is higher than the height difference between the bottom surface of the component and the top surface of the packaging substrate.

[0023] Optionally, the packaging substrate includes an electrical interconnection structure, the electrical interconnection structure includes a bump structure located on the top surface of the packaging substrate, and a ball grid array located on the bottom surface of the packaging substrate, and the packaging substrate is connected to the bottom surface of the chip through the bump structure;

[0024] The gap between the bottom surface of the chip and the top surface of the packaging substrate is filled with a chip bottom filling material, and the chip bottom filling material is the same as the bottom filling layer material of the bottom surface of the component.

[0025] Optionally, the heat dissipation structure is a heat dissipation cover, or a combination structure of a heat sink and a reinforcing rib; the material of the heat dissipation structure is a metal thermal conductive material, and the metal thermal conductive material includes one of copper, aluminum, iron, and stainless steel;

[0026] The thermal interface metal material includes one or more of indium, gallium, and tin.

[0027] In a second aspect, an embodiment of the present application provides a packaging method, including:

[0028] Providing a packaging substrate;

[0029] Mounting chips and components on the top surface of the packaging substrate, wherein the components are located around the chip;

[0030] Forming a protective coating on the surface of the component, the protective coating is at least used to prevent the metal sputtering generated by the melting of the thermal interface metal material from damaging the component;

[0031] attaching a thermal interface metal material to the top surface of the chip;

[0032] Providing a heat dissipation structure, attaching the heat dissipation structure to the top surface of the packaging substrate, and forming a thermal interface material layer between the heat dissipation structure and the chip by welding a thermal interface metal material;

[0033] Wherein, the heat dissipation structure includes a slotted structure, which is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0034] In a third aspect, an embodiment of the present application provides a heat dissipation structure processing method, comprising:

[0035] Acquire processing parameters of the heat dissipation structure, wherein the processing parameters at least include layout parameters of a slotted structure of the heat dissipation structure, wherein the slotted structure is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion; wherein the protective coating is located on the surface of the component, and the protective coating is at least used to prevent metal sputtering generated by welding and melting of the thermal interface metal material from damaging the component;

[0036] The heat dissipation structure is obtained by processing based on the processing parameters of the heat dissipation structure.

[0037] In a fourth aspect, an embodiment of the present application provides an electronic device, wherein the electronic device includes the packaging structure described above.

[0038] The packaging structure provided in the embodiment of the present application includes: a packaging substrate; a chip connected to the packaging substrate, and components located around the chip; a heat dissipation structure connecting the packaging substrate and the chip, wherein the heat dissipation structure and the chip are connected by a thermal interface material layer formed by welding a thermal interface metal material; a protective coating for protecting the surface of the components, the protective coating at least being used to prevent damage to the components by metal sputtering generated by the melting of the thermal interface metal material during welding; the heat dissipation structure including a slotted structure for reserving thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0039] It can be seen that the packaging structure provided in the embodiment of the present application can protect the components by forming a protective coating on the surface of the components to protect the components; because in the welding process of using thermal interface metal materials to weld the heat dissipation structure and the chip together, high temperature may cause the thermal interface metal material to melt and produce metal sputtering, therefore, the protective coating on the surface of the components can effectively prevent the metal sputtering caused by the melting of the thermal interface metal material from damaging the components. At the same time, when designing the heat dissipation structure in the embodiment of the present application, a slotted structure is provided on the heat dissipation structure, which can reserve thermal expansion space for the protective coating, increase the process window, and prevent the protective coating from contacting the heat dissipation structure after thermal expansion, affecting the heat dissipation performance. It can be seen that the packaging structure provided in the embodiment of the present application can effectively avoid damage to the components caused by metal sputtering and protect the components while reducing space occupancy through the protective coating on the surface of the components and the setting of the slotted structure; at the same time, thermal expansion space is reserved for the protective coating, the process window is increased, and the chip packaging effect is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0041] Figure 1 This is an example diagram of a packaging structure;

[0042] Figure 2 is a schematic diagram of a slotted structure of a heat dissipation structure;

[0043] Figure 3 is based on Figure 2 Schematic diagram of the cross section along the AA1 direction;

[0044] Figure 4 is based on Figure 1 An internal top view of a packaging structure;

[0045] Figure 5 This is an example diagram of another packaging structure;

[0046] Figure 6 is a flow chart of a packaging method provided by an embodiment of the present application;

[0047] Figure 7 It is a flow chart of a heat dissipation structure processing method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] Thermal interface material (TIM) plays a vital role in the semiconductor field. It is used to improve the thermal conduction efficiency between semiconductor chips and heat sinks, and to reduce thermal resistance by filling the gap between the chip and the heat sink, thereby improving heat dissipation performance. Thermal interface metal materials are thermal interface materials containing metal components. As the demand for high-performance microprocessors continues to increase, the number of transistors on the chip is also increasing. Therefore, effective thermal management is becoming more and more important.

[0050] In the chip packaging process, in order to ensure the heat dissipation performance of the chip, the chip, thermal interface metal material and heat dissipation structure can be welded together through a welding process to reduce the interface resistance and accelerate the heat dissipation. However, during the above process (such as high-temperature reflow soldering process), since the maximum temperature can reach above 220°C and the melting point of the metal or alloy material used in the thermal interface metal material is relatively low (for example, the melting point of indium is 156°C), metal sputtering may occur, and the sputtered metal may fall on the components around the chip (such as capacitors and / or resistors), thereby causing damage to the components (such as capacitor short circuit).

[0051] A packaging structure that can protect components can be a cover plate (such as a metal cover plate) mounted on top of the components, so that the thermal interface metal material is completely physically isolated from the components, thereby preventing the liquid metal formed by high-temperature melting from splashing onto the components, thereby protecting the components. In other words, the cover plate provides an isolation space for the components, so that at the location of the components, the cover plate is connected to the packaging substrate using an adhesive material, and the components are placed in the isolation space of the cover plate, so that the thermal interface metal material can be completely physically isolated from the components, preventing the liquid metal formed by high-temperature melting from splashing onto the components.

[0052] Although the above packaging structure can play a role in protecting components, the use of the metal cover plate requires a large space, which leads to an increase in the area of ​​the chip layout.

[0053] Furthermore, the above-mentioned packaging structure does not meet the low KOZ (Keep Out Zone) restriction requirements, where the circuit board layout cannot use the KOZ area due to restrictions such as thermal management and mounting. Specifically, a certain thickness needs to be reserved for bonding at the connection between the cover plate and the packaging substrate, and sufficient restricted areas need to be reserved between the bottom of the cover plate and the components and chips to ensure safe operation. This does not meet the low KOZ design requirements of the packaging structure when the metal cover plate occupies a large space.

[0054] Furthermore, for packaging structures with irregular distribution of components (such as capacitors and / or resistors), the cover plate needs to be designed with a corresponding complex structure or designed to a maximum size that can encompass all components to protect the components, which may affect the packaging yield. This is because the complex structural design increases the difficulty of production and is also likely to increase the defect rate.

[0055] In view of this, it is necessary to provide a packaging structure that can avoid damage to components caused by metal sputtering generated during the welding and melting process of thermal interface metal materials while reducing space occupancy, thereby protecting components, increasing the process window, and improving the packaging effect.

[0056] Figure 1 This is an example diagram of a packaging structure. Figure 1 , the packaging structure provided in the embodiment of the present application includes:

[0057] The packaging substrate 101 can be used as a carrier for semiconductor chip packaging and can provide electrical connection, support, protection, heat dissipation and other functions for the chip.

[0058] A chip 102 connected to the packaging substrate 101, and components 103 located around the chip;

[0059] In an optional implementation, the package substrate 101 may include an electrical interconnection structure (not shown in the figure), and the electrical interconnection structure may include a bump structure 104 on the top surface of the package substrate, and a ball grid array (BGA) 105 located on the bottom surface of the package substrate;

[0060] The packaging substrate 101 may be connected to the bottom surface of the chip 102 via the bump structure 104 .

[0061] In an embodiment of the present application, the bump structure 104 may be a C4 (Controlled Collapse Chip Connection) bump structure, or a C2 bump (Bump), wherein the C2 Bump may also be referred to as a micro bump structure, and the size of the C2 bump is smaller than that of the C4 bump, which may achieve a higher input / output (I / O) density, thereby providing more input / output ports in the packaging structure, achieving more sophisticated interconnections, and being suitable for higher performance packaging requirements; in the actual packaging process, the corresponding bump structure may be used for connecting the chip to the packaging substrate according to different packaging requirements and application scenarios.

[0062] The bottom surface of the packaging substrate 101 has solder balls in a ball grid array, such as solder balls, which can provide mechanical support for the packaging substrate and provide an electrical connection path between the packaging substrate and an external circuit.

[0063] Furthermore, in the packaging structure, the gap between the bottom surface of the chip and the top surface of the packaging substrate is filled with a chip bottom filling material 106. After the bottom surface of the chip is connected to the top surface of the packaging substrate through the bump structure, the chip bottom filling material 106 (such as bottom filling glue) can be filled in the gap between the chip and the packaging substrate to protect the bump structure and the chip from physical impact and wear, and reduce damage caused by mechanical stress such as vibration. For example, epoxy resin has good bonding properties and mechanical strength, can provide good mechanical connection, improve the stability and durability of the packaging structure, and can be used as the chip bottom filling material 106.

[0064] In an optional implementation, the chip bottom filling material can be dispensed on the periphery of the chip according to a predetermined pattern, and the chip bottom filling material can fully fill the gap between the bottom surface of the chip and the packaging substrate through capillary action, and then solidify to form a chip bottom filling layer.

[0065] The heat dissipation structure connecting the packaging substrate 101 and the chip 102, in the embodiment of the present application, the heat dissipation structure can be a heat dissipation cover, or a combination structure of a heat sink and a reinforcing rib. Figure 1 The heat dissipation structure in the package structure shown is described by taking the heat dissipation cover 107 as an example. The heat dissipation structure can use metal thermal conductive materials to improve the heat dissipation performance of the heat dissipation structure, thereby better meeting the heat dissipation requirements of the chip. In an optional implementation, the metal thermal conductive material of the heat dissipation structure can include one of copper, aluminum, iron, and stainless steel.

[0066] Furthermore, the heat dissipation structure and the chip 102 may be connected by a thermal interface material layer 108 formed by welding a thermal interface metal material; for example, the heat dissipation structure has a welding interface that matches the thermal interface metal material, and the welding interface of the heat dissipation structure may be welded to the thermal interface metal material on the top surface of the chip 102, thereby forming a thermal interface material layer 108 to connect to the top surface of the chip 102;

[0067] The thermal interface metal material may be a metal or alloy material with a relatively low melting point (eg, the melting point of indium is 156° C.), and the chip, the thermal interface metal material and the heat dissipation structure are welded together through a reflow process to form a thermal interface material layer 108 .

[0068] In an embodiment of the present application, the thermal interface metal material may include one or more of indium, gallium, and tin; indium, gallium, tin, and their alloys all have good thermal conductivity and a low melting point. Therefore, using the above materials as thermal interface metal materials and connecting the chip and the heat dissipation structure helps to improve the heat dissipation performance of the chip.

[0069] During the above process, the maximum temperature can reach above 220°C, which may cause the thermal interface metal material to melt at high temperature and generate metal sputtering, which may fall onto the components around the chip (such as capacitors and / or resistors), thereby causing damage to the components (such as capacitor short circuit) and affecting the product packaging yield. Based on this, the packaging structure provided in the embodiment of the present application includes: a protective coating 200 for protecting the surface of the component 103, and the protective coating 200 is at least used to prevent the metal sputtering generated by the melting of the thermal interface metal material during welding from damaging the components;

[0070] Furthermore, in the embodiment of the present application, during the process of welding to form the thermal interface material layer 108, the protective coating on the surface of the component 103 can protect the component. At the same time, since the protective coating occupies less space, the packaging structure provided by the present application can avoid the metal sputtering generated by the melting of the thermal interface metal material during welding from falling onto the component and causing damage to the component while reducing the space occupied.

[0071] In an optional implementation, the protective coating can fully wrap the surface of the component 103, and the protective coating 200 includes a top coating 109 and a bottom filling layer 110, the top coating 109 covers the top surface and side surfaces of the component 103, and the bottom filling layer 110 covers at least the bottom surface of the component.

[0072] Furthermore, the bottom filling layer 110 also wraps the bottom solder joints on the bottom surfaces of the components 103, and the bottom solder joints are used to connect the components to the packaging substrate 101; wherein, the material forming the bottom filling layer 110 (referred to as the bottom filling layer material) is fluid during the process of forming the bottom filling layer and before solidification, and the bottom filling layer material of the bottom filling layer 110 can fill the gaps between the components and the packaging substrate through capillary action from the common channel between the bottoms of the plurality of components 103 to wrap the bottom solder joints of the components.

[0073] In an embodiment of the present application, the material of the bottom solder joint for welding the bottom surface of the component and the packaging substrate can be a water-wash solder paste; compared with the use of traditional solder paste to form the solder joint between the component and the packaging substrate, the traditional solder paste needs to use flux removal, etc. to remove the solder paste residue on the bottom surface of the capacitor and the top surface of the packaging substrate, while the water-wash solder paste has high wettability and can quickly form solder joints; at the same time, it reduces the solder paste residue and keeps the bottom surface of the capacitor and the top surface of the packaging substrate clean, thereby reducing the flow resistance of the solder paste residue to the bottom filling layer material, which is beneficial to the subsequent full filling of the bottom filling layer 110 material, and avoiding the incomplete filling of the bottom filling layer material caused by the solder paste residue during the high-temperature reflow process, resulting in the material forming unnecessary electrical connections with other structures, causing a short circuit.

[0074] Optionally, the chip bottom filling material 106 filled at the bottom of the chip and the bottom filling layer material filled at the bottom surface of the component may be the same, for example, may be the same type of glue.

[0075] In the embodiment of the present application, the material of the top coating 109 and the material of the bottom filling layer 110 have good interface compatibility, so the top coating can completely cover the top and sides of the component and is compatible with the interface of the bottom filling layer, thereby forming a dense protective coating that fully wraps the surface of the component and protects the component from damage caused by metal sputtering.

[0076] In another optional implementation, the protective coating may partially wrap the surface of the component 103, and the partial surface of the component wrapped by the protective coating may include any of the following: the surface of a critical area of ​​the component (for example, an area in the component where there is a risk of short circuit), the surface of an area of ​​the component corresponding to metal sputtering (for example, the top of the component and the side close to the thermal interface metal material).

[0077] That is to say, the protective coating in the embodiment of the present application can completely wrap the surface of the component, or it can partially wrap the key area of ​​the component to achieve protection of the component and prevent metal from sputtering to the surface of the component and causing damage; in the specific implementation, the corresponding protective coating wrapping method can be adopted according to the spatial layout within the packaging structure and the metal sputtering area.

[0078] In an optional implementation, the material of the top coating 109 (referred to as the top coating material) may be an insulating resin of the polyimide type, epoxy resin, or fluorocarbon resin type.

[0079] Since the top coating is used to protect components from metal sputtering during high-temperature welding, the top coating material needs to be resistant to high temperatures and have high stability. Insulating resins such as polyimide or fluorocarbon resins have good high-temperature resistance (for example, the decomposition temperature of polyimide (PI) can reach about 500°C), and epoxy resin has excellent adhesion, mechanical properties and anti-corrosion properties, so it can be used as a top coating material.

[0080] Specifically, the thermal expansion coefficient CTE of the top coating material is less than 50ppm / ℃, the glass transition temperature Tg>150℃, and the resistivity Rc>10 11 ohm.cm.

[0081] The coefficient of thermal expansion CTE is a physical quantity that measures the dimensional change of a material when the temperature changes. A CTE less than 50ppm / ℃ can ensure that the material has good stability and reduce thermal expansion. The glass transition temperature Tg is the temperature at which the material changes from the glass state to the rubber state. Tg>150℃ can ensure that the material can maintain rigidity and stability at high temperatures. The resistivity Rc is a physical quantity that measures the conductivity of the material. Rc>10 11 Ohm.cm can ensure that the material has good insulation performance; therefore, the material that meets the above conditions is used as the top coating material to meet the insulation protection of components and thermal expansion process conditions.

[0082] During the process of forming the thermal interface material layer by the above-mentioned high-temperature welding, the high temperature may cause the protective coating to expand. If the protective coating expands, it may cause the protective coating to contact the heat dissipation structure. Under high temperature conditions, the flow of the protective coating material in contact with the heat dissipation structure may form an additional electrical connection, resulting in a short circuit, while affecting the heat dissipation effect and reducing the heat dissipation performance. Therefore, when designing the heat dissipation structure, the embodiment of the present application needs to consider the size of the expanded protective coating, reserve a certain amount of thermal expansion space for the protective coating, and prevent the protective coating from contacting the heat dissipation structure after thermal expansion. Specifically, the heat dissipation structure can be provided with a slotted structure 201, which is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0083] Figure 2 It is a schematic diagram of the slotted structure of the heat dissipation structure. Figure 3 is based on Figure 2 Schematic diagram of the cross section in the AA1 direction, combined with Figure 1 , Figure 2 and Figure 3In the embodiment of the present application, the heat dissipation structure includes: a slotted structure 201, which is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion. The heat dissipation structure also includes a support column 202 and an inner cavity plane structure 203. The support column 202 of the heat dissipation structure can be bonded to the packaging substrate 101 by an adhesive 111, and the inner cavity plane structure 203 is the area where the heat dissipation structure and the thermal interface material layer 108 are welded.

[0084] In the embodiment of the present application, a slotted structure 201 is provided in the heat dissipation structure to reserve thermal expansion space for the protective coating, expand the process window, and prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0085] In the embodiment of the present application, when setting the slotted structure of the heat dissipation structure, it is necessary to ensure that there is space reserved for thermal expansion of the protective coating so that the expanded protective coating does not contact the heat dissipation structure. Therefore, the size of the slotted structure needs to be reasonably set.

[0086] In an optional implementation, the slot size of the slotted structure may be designed to reserve thermal expansion space for the protective coating in an expansion direction of the protective coating corresponding to the slot size.

[0087] That is to say, when designing the size of the slotted structure, the corresponding size design can be performed according to the expansion direction of the protective coating, thereby ensuring that the thermal expansion space reserved for the protective coating (i.e., the size of the slotted structure) can fully accommodate the portion of the protective coating that is higher than the height of the inner cavity plane structure 203 after the expansion of the protective coating, thereby ensuring that this portion of the protective coating does not contact the heat dissipation structure at all.

[0088] Further, in an optional implementation, the slot size may include a slot width and a slot depth.

[0089] Since the top coating in the protective coating covers the top and side surfaces of the component, the protective coating on the top and sides of the component will expand, combined with Figures 1 to 3 ,It can be seen that the expansion direction of the protective coating on both sides corresponds to the width of the groove structure, and the expansion direction of the protective coating on the top surface corresponds to the depth of the groove structure.

[0090] Therefore, the groove width of the groove structure can be designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the groove width; the groove depth of the groove structure can be designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the groove depth.

[0091] Furthermore, the slotted structure may be a top slotted structure of a heat dissipation cover;

[0092] In an optional embodiment, the expansion direction of the protective coating on both sides is a horizontal expansion direction, and the expansion direction of the protective coating on the top surface is a vertical expansion direction.

[0093] Therefore, the groove width of the top groove structure can be designed to reserve thermal expansion space for the protective coating in the horizontal expansion direction of the protective coating; the groove depth of the top groove structure can be designed to reserve thermal expansion space for the protective coating in the vertical expansion direction of the protective coating.

[0094] In an optional implementation, the width of the top groove structure is not less than the width of the protective coating. For example, the depth of the top groove structure may range from 50 μm to 200 μm.

[0095] It can be understood that the width of the top groove structure is not less than the width of the protective coating to ensure that the width of the top groove structure can fully accommodate the width of the expanded protective coating, and prevent the protective coating from expanding and causing part of the protective coating to be unable to be accommodated by the top groove structure, causing the part of the protective coating to touch the heat dissipation structure and affect the heat dissipation effect.

[0096] When setting the depth of the top slotted structure, if the slotted depth is too low and cannot accommodate part of the expanded protective coating, this part of the protective coating may touch the heat dissipation structure, that is, the reserved thermal expansion space is too small and the expected accommodation effect cannot be achieved; if the slotted depth is too high, the expanded protective coating may not use the top slotted structure, resulting in a waste of space layout. At the same time, if the slotted depth is too high, the thickness of some areas of the heat dissipation structure may be low, affecting the heat dissipation effect of the heat dissipation structure. Therefore, it is necessary to reasonably set the height of the top slotted structure according to the expansion height of the protective coating material. That is to say, the height of the top slotted structure can be designed according to the expansion height of the protective coating material. For example, the height range of the top slotted structure can be set to 50μm to 200μm.

[0097] Further, Figure 4 is based on Figure 1 The internal top view of the package structure, combined with Figure 1 and Figure 4 The packaging structure further includes: a barrier layer 112 surrounding the periphery of the component 103, and the barrier layer 112 is used to prevent the bottom filling layer material of the bottom filling layer 110 on the bottom surface of the component from overflowing.

[0098] In the embodiment of the present application, since the bottom filling glue at the bottom of the component needs to completely wrap the solder joints between the component and the packaging substrate to achieve sufficient filling, a material with strong fluidity is selected as the bottom filling layer material of the bottom filling layer 110. However, the bottom filling layer material of the bottom filling layer 110 may overflow from the packaging substrate, which may have an adverse effect on subsequent mounting. Therefore, a barrier layer 112 may be set around the component 103 to prevent the bottom filling layer material of the bottom filling layer 110 from overflowing.

[0099] In the embodiment of the present application, the material of the barrier layer 112 may be a glue with a suitable viscosity, such as an adhesive used to connect a packaging substrate and a heat dissipation structure.

[0100] In order to ensure that the barrier layer can completely block the overflow of the bottom filling layer material, the height of the bottom filling layer 110 on the bottom surface of the component needs to be considered when setting the height of the barrier layer.

[0101] In an optional implementation, the height of the barrier layer 112 is higher than the height difference between the bottom surface of the component and the top surface of the packaging substrate, so that the barrier layer can completely block the material of the bottom filling layer 110 from overflowing.

[0102] Further, in the embodiment of the present application, the barrier layer 112 is located in the area between the bottom of the heat dissipation structure and the bottom of the component 103, so that the distance between the bottom of the component and the bottom of the heat dissipation structure can be less than 1.5 mm (i.e. Figure 4 Low KOZ requirement of d<1.5mm).

[0103] As an optional implementation, Figure 5 This is an example diagram of another packaging structure. Figure 5 and Figure 1 The same structure can refer to the corresponding description above, refer to Figure 5 The heat dissipation structure provided in the embodiment of the present application may also be a combination structure of a heat sink 113 and a reinforcing rib 114.

[0104] The heat sink 113 is a metal sheet used for heat dissipation, which transfers heat to the air by increasing the surface area to achieve the purpose of heat dissipation; the reinforcing rib 114 is a structure used to enhance the structural rigidity and strength, and can be used to support the heat sink; the cavity structure formed by the heat sink 113 and the reinforcing rib 114 can accommodate the chip and components around the chip. The heat sink 113 and the reinforcing rib 114 are used in combination to improve the heat dissipation efficiency and structural stability.

[0105] It can be seen that the packaging structure provided in the embodiment of the present application can protect the components by forming a protective coating on the surface of the components to protect the components; because in the welding process of using thermal interface metal materials to weld the heat dissipation structure and the chip together, high temperature may cause the thermal interface metal material to melt and produce metal sputtering, therefore, the protective coating on the surface of the components can effectively prevent the metal sputtering caused by the melting of the thermal interface metal material from damaging the components. At the same time, when designing the heat dissipation structure in the embodiment of the present application, a slotted structure is provided on the heat dissipation structure, which can reserve thermal expansion space for the protective coating, increase the process window, and prevent the protective coating from contacting the heat dissipation structure after thermal expansion, affecting the heat dissipation performance. It can be seen that the packaging structure provided in the embodiment of the present application can effectively avoid damage to the components caused by metal sputtering and protect the components while reducing space occupancy through the protective coating on the surface of the components and the setting of the slotted structure; at the same time, thermal expansion space is reserved for the protective coating, the process window is increased, and the chip packaging effect is improved.

[0106] The embodiment of the present application further provides a packaging method, and the packaging method described below can be referenced in correspondence with the contents of the packaging structure described above.

[0107] Figure 6 is a flow chart of a packaging method provided in an embodiment of the present application, referring to Figure 6 , the packaging method may include:

[0108] Step S601: providing a packaging substrate, mounting components and chips on the top surface of the packaging substrate, wherein the components are located around the chip.

[0109] In an optional implementation, the step of mounting components on the top surface of the packaging substrate may include: forming solder joints between the bottom surface of the component and the top surface of the packaging substrate, and soldering the component and the packaging substrate together through the solder joints; wherein the material of the solder joints may be water-wash solder paste, which can quickly form solder joints while keeping them clean, thereby facilitating sufficient filling of the subsequent bottom filling layer.

[0110] The step of mounting a chip on the top surface of the packaging substrate may include: forming a bump structure on the top surface of the packaging substrate, the chip being connected to the packaging substrate via the bump structure; and filling a chip bottom filling material in a gap between the bottom surface of the chip and the top surface of the packaging substrate.

[0111] In an optional implementation, the chip bottom filling material can be dispensed on the periphery of the chip according to a predetermined pattern, and through capillary action, the chip bottom filling material can fully fill the gap between the bottom surface of the chip and the packaging substrate, completely wrap the bump structure, and then solidify; wherein, the chip bottom filling material can be the same as the bottom filling layer material of the bottom surface of the component, for example, it can be the same type of glue.

[0112] In the embodiment of the present application, during the chip mounting process, the chip structure can be mounted face down on the top surface of the packaging substrate in a flip-chip manner to complete the chip mounting.

[0113] Step S602: forming a protective coating on the surface of the component, wherein the protective coating is at least used to prevent the component from being damaged by metal sputtering generated by the melting of the thermal interface metal material during welding.

[0114] In the embodiment of the present application, since thermal interface metal materials are required in the subsequent packaging process, the chip, thermal interface metal materials and heat dissipation structure are welded. During this welding process, the high temperature will cause the thermal interface metal material to melt and produce metal sputtering, which will fall to the surface of the component and cause damage. Therefore, it is necessary to form a protective coating on the surface of the component to prevent metal sputtering from damaging the component.

[0115] In an optional implementation, the protective coating can completely wrap the surface of the component; the step of forming the protective coating on the surface of the component may include: applying the bottom filling layer material on the bottom of the component through a dispensing process, and after the bottom filling layer material covers the bottom surface (called the bottom surface) of the component, solidifying to form a bottom filling layer; applying the top coating material on the top of the component through a dispensing process, and after the top coating material covers the top surface (called the top surface) and side surfaces of the component, solidifying to form a top coating.

[0116] Furthermore, the bottom filling layer also includes a bottom solder joint on the bottom surface of the component, and the bottom solder joint is used to connect the component with the packaging substrate; the dispensing process of the bottom filling layer material at the bottom of the component may include:

[0117] Applying a bottom filling layer material in a common channel region between the bottoms of the plurality of components by a dispensing process, so that the bottom filling layer material fills the gap between the components and the packaging substrate through a capillary action from the common channel region and wraps the bottom solder joints of the components;

[0118] The bottom filling layer material has fluidity during the process of forming the bottom filling layer and before solidification, and the glue spotting area at the bottom of the component is a common channel area between the bottoms of multiple components.

[0119] The dispensing of the top coating material on the top of the component by the dispensing process may include:

[0120] Reciprocatingly applying a top coating material on the top of the component by a dispensing process, wherein the dispensing area on the top of the component is the top of the component;

[0121] In an optional implementation, the area of ​​the glue dispensing region on the top of the component can be larger than the top area of ​​the component, thereby ensuring that the top coating material can fully cover the top surface and side surfaces of the component.

[0122] In an embodiment of the present application, the dispensing process for forming the top coating can adopt a reciprocating dispensing method, that is, during the dispensing process, the top coating material is fully dispensed on the top surface of the component through a continuous, back-and-forth motion; wherein the dispensing trajectory of the reciprocating dispensing can be a straight line, an arc, or other trajectory that adapts to the top surface shape of the component, so as to fully cover the top surface and side surfaces of the component to form a top coating.

[0123] As an optional implementation, the protective coating may partially wrap the surface of the component, and the partial surface of the component wrapped by the protective coating may include any of the following: the surface of a critical area of ​​the component (for example, an area in the component where there is a risk of short circuit), the surface of an area of ​​the component corresponding to metal sputtering (for example, the top of the component and the side close to the thermal interface metal material).

[0124] Accordingly, in another optional implementation, the surface of the key area of ​​the component or the surface of the corresponding metal sputtering area can be coated by a dispensing process and then cured to form a protective coating.

[0125] That is to say, the protective coating in the embodiment of the present application can completely wrap the surface of the component, or it can partially wrap the key area of ​​the component to achieve protection of the component and prevent metal from sputtering to the surface of the component and causing damage; in the specific implementation, the corresponding protective coating wrapping method can be adopted according to the spatial layout within the packaging structure and the metal sputtering area.

[0126] Furthermore, before forming a protective coating on the surface of the component, a barrier layer is formed around the periphery of the component, and the barrier layer is used to prevent the bottom filling layer material of the bottom surface of the component from overflowing; wherein the height of the barrier layer is higher than the height difference between the bottom surface of the component and the top surface of the packaging substrate.

[0127] Step S603: attaching a thermal interface metal material to the top surface of the chip.

[0128] In an optional implementation, the step of mounting the thermal interface metal material on the top surface of the chip may include: coating a three-layer stacked structure of flux, thermal interface metal material and flux on the surface of the chip, or using a gas flux-free reflow method such as formic acid to achieve sufficient welding of the thermal interface metal material with the chip and the heat dissipation structure.

[0129] Step S604: Provide a heat dissipation structure, mount the heat dissipation structure to the top surface of the packaging substrate, and form a thermal interface material layer between the heat dissipation structure and the chip by welding a thermal interface metal material; wherein the heat dissipation structure includes a groove structure for reserving thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0130] In the embodiment of the present application, during the high-temperature welding process, the high temperature may cause the protective coating to expand. If the protective coating expands, it may cause the protective coating to contact the heat dissipation structure. Under high temperature conditions, the flow of the protective coating material in contact with the heat dissipation structure may form an additional electrical connection, resulting in a short circuit, while affecting the heat dissipation effect and reducing the heat dissipation performance. Therefore, when designing the heat dissipation structure, it is necessary to consider the size of the protective coating after expansion, reserve a certain amount of thermal expansion space for the protective coating, and prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0131] In an optional implementation, the slotting size of the slotting structure can be designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slotting size of the protective coating; wherein the slotting size includes a slotting width and a slotting depth; the slotting width of the slotting structure can be designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slotting width; the slotting depth of the slotting structure can be designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slotting depth.

[0132] Furthermore, in an optional implementation, forming a thermal interface material layer between the heat dissipation structure and the chip by welding a thermal interface metal material includes: after mounting the heat dissipation structure to the top surface of the packaging substrate, welding and melting the thermal interface metal material to form a thermal interface material layer by a reflow soldering process; the method also includes: forming a ball grid array on the bottom surface of the packaging substrate by a ball planting process.

[0133] The present application also provides a method for processing a heat dissipation structure. Figure 7 is a flow chart of a heat dissipation structure processing method provided in an embodiment of the present application, referring to Figure 7 The heat dissipation structure processing method includes the following steps.

[0134] Step S701: Acquire processing parameters of the heat dissipation structure, wherein the processing parameters include at least layout parameters of a slotted structure of the heat dissipation structure, wherein the slotted structure is used to reserve thermal expansion space for a protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion; wherein the protective coating is located on the surface of components, and the protective coating is at least used to prevent damage to components caused by metal sputtering generated by welding and melting of thermal interface metal materials.

[0135] In an embodiment of the present application, in order to protect the components around the chip and avoid metal sputtering caused by the melting of the thermal interface metal material during welding, a protective coating can be formed on the surface of the component, wherein the protective coating is located on the surface of the component, and the protective coating is at least used to prevent the metal sputtering caused by the melting of the thermal interface metal material during welding from damaging the component. However, during high-temperature welding, the protective coating will expand and come into contact with the heat dissipation structure, thereby affecting the heat dissipation effect of the heat dissipation structure. Therefore, it is necessary to machine a slotted structure in the heat dissipation structure to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

[0136] In the actual processing process, the heat dissipation structure to be processed can be firstly obtained by one-piece stamping or machining and milling.

[0137] Furthermore, in order to process the slotted structure on the heat dissipation structure to be processed, it is necessary to first obtain processing parameters of the heat dissipation structure, wherein the processing parameters may include layout parameters of the slotted structure.

[0138] In an optional implementation, the layout parameters of the slotted structure include at least the slotted dimensions of the slotted structure, and the slotted dimensions of the slotted structure are designed to reserve thermal expansion space for the protective coating in the expansion direction of the protective coating corresponding to the slotted dimensions; wherein the slotted dimensions may include a slotted width and a slotted depth.

[0139] Since the top coating in the protective coating covers the top surface and side surfaces of the component, the protective coating on the top surface and both sides of the component will expand, wherein the expansion direction of the protective coating on both sides of the component corresponds to the width of the slot structure, and the expansion direction of the protective coating on the top surface of the component corresponds to the depth of the slot structure.

[0140] Therefore, the groove width of the groove structure can be designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the groove width; the groove depth of the groove structure can be designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the groove depth.

[0141] Step S702: processing the heat dissipation structure based on the processing parameters of the heat dissipation structure.

[0142] In the embodiment of the present application, the heat dissipation structure may be obtained by processing in the following manner: laser processing or CNC machine tool processing.

[0143] For example, based on the processing parameters of the heat dissipation structure determined above, a computer numerical control (CNC) system can control the corresponding packaging process device to process the heat dissipation structure, thereby obtaining a slotted structure of corresponding size, so that the packaging structure of the embodiment of the present application can reserve thermal expansion space for the protective coating while using the protective coating to protect components, thereby increasing the process window and preventing the protective coating from expanding and contacting the heat dissipation structure, causing a short circuit, affecting the heat dissipation performance, and further affecting the packaging effect.

[0144] An embodiment of the present application also provides an electronic device, such as a computer device, including but not limited to a terminal device or a server device; wherein the electronic device includes the packaging structure described in the above embodiment.

[0145] The above describes multiple implementation schemes provided by the embodiments of the present application. The various optional methods introduced in each implementation scheme can be combined and cross-referenced with each other without conflict, thereby extending a variety of possible implementation schemes, which can all be considered as implementation schemes disclosed and open in the embodiments of the present application.

[0146] Although the embodiments of the present application are disclosed above, the present application is not limited thereto. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be subject to the scope defined by the claims.

Claims

1. A packaging structure, characterized in that: include: Package substrate; A chip connected to the packaging substrate, and components located around the chip; A heat dissipation structure connecting the package substrate and the chip, wherein the heat dissipation structure and the chip are connected through a thermal interface material layer formed by welding a thermal interface metal material; A protective coating for protecting the surface of components, the protective coating is at least used to prevent the metal sputtering generated by the melting of the thermal interface metal material from damaging the components; Wherein, the heat dissipation structure includes a slotted structure, which is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

2. The packaging structure according to claim 1, characterized in that: The protective coating completely wraps the surface of the component, and the protective coating includes a top coating and a bottom filling layer, wherein the top coating covers the top surface and side surfaces of the component, and the bottom filling layer at least covers the bottom surface of the component.

3. The packaging structure according to claim 2, characterized in that: The bottom filling layer also wraps the bottom solder joints on the bottom surface of the components, and the bottom solder joints are used to connect the components to the packaging substrate; Among them, the bottom filling layer material forming the bottom filling layer is fluid during the process of forming the bottom filling layer and before solidification. The bottom filling layer material fills the gap between the components and the packaging substrate through capillary action from the common channel area between the bottoms of the multiple components to wrap the bottom solder joints of the components.

4. The packaging structure according to any one of claims 1 to 3, characterized in that: The slot size of the slot structure is designed to reserve thermal expansion space for the protective coating in the expansion direction of the protective coating corresponding to the slot size.

5. The packaging structure according to claim 4, characterized in that: The slotting dimensions include slotting width and slotting depth; The slot width of the slot structure is designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slot width of the protective coating; The groove depth of the groove structure is designed to reserve thermal expansion space for the protective coating in the expansion direction of the protective coating corresponding to the groove depth.

6. The packaging structure according to claim 5, characterized in that: The slotted structure is a top slotted structure of the heat dissipation structure, and the slotted width of the top slotted structure is designed to reserve thermal expansion space for the protective coating in the horizontal expansion direction of the protective coating; The groove depth of the top groove structure is designed to reserve thermal expansion space for the protective coating in the vertical expansion direction of the protective coating.

7. The packaging structure according to claim 6, characterized in that: The width of the top groove structure is not less than the width of the protective coating.

8. The packaging structure according to any one of claims 2 to 3, characterized in that: Also includes: A barrier layer surrounding the periphery of the component, the barrier layer being used to prevent the bottom filling layer material on the bottom surface of the component from overflowing; Wherein, the height of the barrier layer is higher than the height difference between the bottom surface of the component and the top surface of the packaging substrate.

9. The packaging structure according to any one of claims 2 to 3, characterized in that: The package substrate comprises an electrical interconnection structure, wherein the electrical interconnection structure comprises a bump structure located on a top surface of the package substrate and a ball grid array located on a bottom surface of the package substrate, and the package substrate is connected to a bottom surface of a chip through the bump structure; The gap between the bottom surface of the chip and the top surface of the packaging substrate is filled with a chip bottom filling material, and the chip bottom filling material is the same as the bottom filling layer material of the bottom surface of the component.

10. The packaging structure according to claim 1, characterized in that: The heat dissipation structure is a heat dissipation cover, or a combination of a heat sink and a reinforcing rib; the material of the heat dissipation structure is a metal heat conductive material, and the metal heat conductive material includes one of copper, aluminum, iron, and stainless steel; The thermal interface metal material includes one or more of indium, gallium, and tin.

11. A packaging method, characterized in that: include: Providing a packaging substrate; Mounting chips and components on the top surface of the packaging substrate, wherein the components are located around the chip; Forming a protective coating on the surface of the component, the protective coating is at least used to prevent the metal sputtering generated by the melting of the thermal interface metal material from damaging the component; attaching a thermal interface metal material to the top surface of the chip; Providing a heat dissipation structure, attaching the heat dissipation structure to the top surface of the packaging substrate, and forming a thermal interface material layer between the heat dissipation structure and the chip by welding a thermal interface metal material; Wherein, the heat dissipation structure includes a slotted structure, which is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion.

12. The packaging method according to claim 11, characterized in that: The protective coating fully wraps the surface of the component; The step of forming a protective coating on the surface of the component comprises: Applying a bottom filling layer material at the bottom of the component by a dispensing process, and curing to form a bottom filling layer at least after the bottom filling layer material covers the bottom surface of the component; The top coating material is dispensed on the top of the component by a dispensing process, and after the top coating material covers the top surface and the side surface of the component, it is cured to form a top coating.

13. The packaging method according to claim 12, characterized in that: The bottom filling layer also includes a bottom solder joint on the bottom surface of the component, and the bottom solder joint is used to connect the component to the packaging substrate; The step of applying the bottom filling layer material on the bottom of the component by a dispensing process comprises: Applying a bottom filling layer material in a common channel region between the bottoms of the plurality of components by a dispensing process, so that the bottom filling layer material fills the gap between the components and the packaging substrate through a capillary action from the common channel region and wraps the bottom solder joints of the components; The bottom filling layer material has fluidity during the process of forming the bottom filling layer and before solidification, and the common channel area between the bottoms of the plurality of components is the glue dispensing area at the bottom of the components.

14. The packaging method according to claim 12, characterized in that: The dispensing of the top coating material on the top of the component by the dispensing process comprises: The top coating material is reciprocatingly applied on the top of the component through a dispensing process so that the top coating material fully covers the top surface and side surfaces of the component; wherein the top of the component is the dispensing area on the top of the component.

15. The packaging method according to claim 12, characterized in that: The packaging method further comprises: Before forming a protective coating on the surface of the component, forming a barrier layer around the periphery of the component, the barrier layer is used to prevent the bottom filling layer material on the bottom surface of the component from overflowing; Wherein, the height of the barrier layer is higher than the height difference between the bottom surface of the component and the top surface of the packaging substrate.

16. The packaging method according to any one of claims 11 to 15, characterized in that: The slot size of the slot structure is designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slot size of the protective coating; Wherein, the slot size includes slot width and slot depth; The slot width of the slot structure is designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slot width of the protective coating; The groove depth of the groove structure is designed to reserve thermal expansion space for the protective coating in the expansion direction of the protective coating corresponding to the groove depth.

17. The packaging method according to any one of claims 12 to 15, characterized in that: The step of mounting a chip on the top surface of the packaging substrate comprises: forming a bump structure on the top surface of the packaging substrate, wherein the chip is connected to the packaging substrate through the bump structure; filling a chip bottom filling material in a gap between the bottom surface of the chip and the top surface of the packaging substrate, wherein the chip bottom filling material is the same as the bottom filling layer material of the bottom surface of the component; The step of forming a thermal interface material layer between the heat dissipation structure and the chip by welding a thermal interface metal material comprises: After the heat dissipation structure is mounted on the top surface of the package substrate, the thermal interface metal material is welded and melted by a reflow process to form a thermal interface material layer; The method further comprises: A ball grid array is formed on the bottom surface of the packaging substrate through a ball planting process.

18. A method for processing a heat dissipation structure, characterized in that: include: Acquire processing parameters of the heat dissipation structure, wherein the processing parameters at least include layout parameters of a slotted structure of the heat dissipation structure, wherein the slotted structure is used to reserve thermal expansion space for the protective coating to prevent the protective coating from contacting the heat dissipation structure after thermal expansion; wherein the protective coating is located on the surface of the component, and the protective coating is at least used to prevent metal sputtering generated by welding and melting of the thermal interface metal material from damaging the component; The heat dissipation structure is obtained by processing based on the processing parameters of the heat dissipation structure.

19. The heat dissipation structure processing method according to claim 18, characterized in that: The layout parameters of the slotted structure at least include the slotted size of the slotted structure, and the slotted size of the slotted structure is designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slotted size of the protective coating; Wherein, the slot size includes slot width and slot depth; The slot width of the slot structure is designed to reserve thermal expansion space for the protective coating in the expansion direction corresponding to the slot width of the protective coating; The groove depth of the groove structure is designed to reserve thermal expansion space for the protective coating in the expansion direction of the protective coating corresponding to the groove depth.

20. An electronic device, characterized in that: Comprising the packaging structure as described in any one of claims 1-10.

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