Packaging structure, electronic device and chip packaging method

Abstract

The present application provides a packaging structure, an electronic device, and a chip packaging method. The packaging structure includes: a substrate, a chip, a support portion, and a heat-conducting cover plate. The chip is mounted on the surface of the substrate, and the heat-conducting cover plate is disposed on the side of the chip facing away from the substrate. The surface of the heat-conducting cover plate facing the substrate has a filling area opposite to the chip, and the filling area has a receiving groove opening toward the substrate. A thermal interface material layer is filled between the chip and the bottom surface of the receiving groove. A first gap communicating with the receiving groove is provided between the opening edge of the receiving groove and the substrate. When preparing the packaging structure, the opening of the receiving groove is directed upward, and a pipe is used to pour the filling material into the receiving groove through the first gap. The filling material wraps the side of the thermal interface material layer to isolate the side of the thermal interface material layer from the air. The thermal interface material layer is not easily deteriorated by the reaction with components in the air, ensuring good thermal contact between the chip and the heat-conducting cover plate, which is conducive to stable heat dissipation of the chip.

Description

Technical Field

[0001] The present application relates to the field of chip packaging technology, and in particular to a packaging structure, an electronic device, and a chip packaging method. Background Art

[0002] Chips (such as the bare die in a central processing unit) generate heat during operation. In particular, as Moore's Law indicates, the number of transistors in a chip increases, and the amount of heat generated also increases. Therefore, a heat sink is needed to dissipate heat from the chip to prevent overheating and performance degradation. For example, a metal integrated heat spreader (IHS) contacts one surface of the chip and dissipates the heat.

[0003] When the heat sink and chip surfaces come into contact, a certain air gap forms between them due to the roughness of both surfaces. Air has poor thermal conductivity, resulting in a large interfacial thermal resistance between the heat sink and chip. To reduce this thermal resistance, a thermal interface material (TIM) with good thermal conductivity is typically placed between the two contacting surfaces to bridge this air gap.

[0004] The above thermal interface materials are easily deteriorated by reacting with components in the air, thereby reducing the thermal conductivity. For example, when metal indium is used as the thermal interface material, the metal indium is easily oxidized or sulfurized when exposed to air. Summary of the Invention

[0005] The present application provides a packaging structure, an electronic device, and a chip packaging method for preventing a thermal interface material layer between a chip and a heat-conducting cover plate from deteriorating due to interaction with components in the air, thereby ensuring good heat dissipation of the chip.

[0006] In a first aspect, a packaging structure is provided, which is applied to electronic devices such as servers, mobile phones or tablet computers. The packaging structure includes: a substrate, a heat-conducting cover plate and at least one chip, wherein each chip is mounted on the same surface of the substrate, and the heat-conducting cover plate is arranged on the side of the at least one chip facing away from the substrate; the surface of the heat-conducting cover plate facing the substrate has at least one filling area, each filling area corresponds to one or more chips of the at least one chip, each filling area has a receiving groove with an opening facing the substrate, a thermal interface material layer is filled between each chip and the bottom surface of the corresponding receiving groove, and a first gap connected to the receiving groove is formed between at least part of the opening edge of each receiving groove and the substrate. When preparing the packaging structure, the opening of each receiving groove is directed upward, and a pipe is used to pour filling material into the receiving groove through the first gap corresponding to each receiving groove. In each receiving groove, the filling material wraps the side of each thermal interface material layer. Thus, the filling material isolates the side of the thermal interface material layer from the air, and components such as oxygen and moisture in the air cannot contact the thermal interface material layer. The thermal interface material layer is not easily deteriorated by the reaction with components in the air, thereby ensuring good thermal contact between each chip and the heat-conducting cover plate, which is beneficial to stable heat dissipation of the chip.

[0007] There are many ways to form a receiving groove. In a specific embodiment, a surrounding wall connected to the heat-conducting cover plate is provided along the edge of each filling area, and each surrounding wall and the corresponding filling area form a receiving groove.

[0008] In a specific embodiment, a first gap is formed between each surrounding wall and the substrate, so that the pipeline can extend above the opening of the receiving groove and pour the filling material into it, which is conducive to releasing the stress of the substrate caused by temperature difference.

[0009] In order to take into account both the fillable depth of each receiving groove and the passage of the pipeline, in a specific embodiment, the width of each first gap is between 30 μm and 2 mm.

[0010] In addition to maintaining a first gap between the surrounding wall and the substrate, in a specific embodiment, the pipe for pouring the filling material can be extended to the opening of the receiving groove in the following manner: an extension wall is connected between the end of each surrounding wall away from the heat-conducting cover plate and the substrate, and the extension wall has a hollow extending from the surrounding wall to the substrate, and the hollow forms the above-mentioned first gap for the pipeline to pass through.

[0011] There are many ways to connect the surrounding wall and the heat-conducting cover plate. In one specific embodiment, each surrounding wall and the heat-conducting cover plate are split structures; in another specific embodiment, each surrounding wall and the heat-conducting cover plate are integrated structures.

[0012] In a specific embodiment, another form of forming the receiving groove is that each filling area is concave inwardly away from the substrate to form a receiving groove.

[0013] In one specific embodiment, the package structure further includes a support portion disposed between the substrate and the thermally conductive cover plate and connected to each of the substrate and the thermally conductive cover plate. The support portion surrounds the receiving slot corresponding to the at least one chip, wherein a second gap corresponding to each first gap is formed between a portion of the support portion and the substrate. When pouring filler material into the receiving slot, the pipe first passes through the second gap, then through the first gap corresponding to the receiving slot to be filled, and reaches the opening of the designated receiving slot. The filling material is then poured into the receiving slot.

[0014] In a specific embodiment, the support portion and the heat-conducting cover plate are separate structures. In addition, the support portion and the heat-conducting cover plate may also be an integrated structure.

[0015] In one specific embodiment, the melting point of the filling material in each receiving slot is higher than the melting point of each thermal interface material layer. When the package structure is mounted on a circuit board using a high-temperature method such as reflow soldering, the thermal interface material layer melts, but the filling material surrounding the thermal interface material layer remains solid, preventing the melted thermal interface material layer from flowing. After cooling, the thermal interface material layer cools again, maintaining good thermal contact between the chip and the thermally conductive cover plate.

[0016] In a specific embodiment, in each receiving groove, the filling material covers at least a portion of the side surface of each chip to prevent the formation of gaps between the chip and the thermal interface material layer due to different thermal expansion coefficients of the chip and the substrate, which is conducive to ensuring stable heat dissipation of the chip.

[0017] For example, in a specific embodiment, in each receiving groove, the material of each thermal interface material layer is indium, indium / silver, tin / silver / copper, or indium / tin / bismuth;

[0018] The filling material is made of one or more of silica gel, polyolefin resin, epoxy resin, modified epoxy resin, silicone resin and modified silicone resin.

[0019] In a second aspect, an electronic device is provided, which may be a server, mobile phone, tablet computer, or the like. The electronic device comprises a circuit board and a packaging structure according to any of the above technical solutions, wherein a substrate is mounted on and electrically connected to the circuit board. In this electronic device, because the thermal interface material layer is covered by a filler material, it is protected from deterioration by interaction with airborne components, ensuring thermal stability of the chip and improving the performance of the electronic device.

[0020] In a third aspect, a chip packaging method is provided, comprising at least the following steps:

[0021] mounting at least one chip on a surface of the substrate;

[0022] Mounting a heat-conducting cover plate on a side of the at least one chip facing away from the substrate, wherein the surface of the heat-conducting cover plate facing the substrate has at least one filling area, each filling area corresponds to one or more chips of the at least one chip, each filling area has a receiving groove opening toward the substrate, a thermal interface material layer is filled between each chip and the bottom surface of the corresponding receiving groove, and a first gap is defined between at least a portion of the opening edge of each receiving groove and the substrate, communicating with the receiving groove;

[0023] Filling material is injected into the receiving grooves through the first gap corresponding to each receiving groove and solidified. In each receiving groove, the filling material at least wraps the side surface of the thermal interface material layer.

[0024] In a specific embodiment, before mounting the heat conductive cover plate on the side of at least one chip facing away from the substrate, the method further includes:

[0025] An accommodating groove is formed at each filling area of the heat-conducting cover plate.

[0026] There are many ways to form the receiving groove. In one specific embodiment, the receiving groove is formed at each filling area of the heat conductive cover plate, specifically including:

[0027] A surrounding wall is formed along the edge of each filling area of the heat-conducting cover plate, and each surrounding wall and the corresponding filling area form a receiving groove.

[0028] In another specific embodiment, forming a receiving groove at each filling area of the heat conductive cover plate specifically includes:

[0029] A groove recessed toward the interior of the heat-conducting cover plate is formed in each filling region of the heat-conducting cover plate, and each groove constitutes an accommodating slot.

[0030] In a specific embodiment, the heat-conducting cover plate is mounted on a side of the at least one chip facing away from the substrate, specifically comprising:

[0031] Fixing at least one extension wall to the substrate, wherein each extension wall surrounds one or more chips, and a surrounding wall is provided along an end of each extension wall away from the substrate, and each extension wall has a hollow extending from the substrate to the corresponding surrounding wall to form a first gap;

[0032] A heat-conducting cover plate is placed on a side of at least one chip facing away from the substrate, and an end of each surrounding wall away from the corresponding extension wall is connected to the heat-conducting cover plate, wherein each surrounding wall extends along the edge of a corresponding filling area, and each surrounding wall and the corresponding filling area form a receiving groove.

[0033] In a specific embodiment, the heat conductive cover is mounted on a side of at least one chip facing away from the substrate, specifically comprising:

[0034] fixing the support portion to the substrate, wherein the support portion surrounds the at least one chip and a second gap is formed between a portion of the support portion and the substrate;

[0035] The heat-conducting cover plate is placed on a side of at least one chip facing away from the substrate, and one end of the support portion away from the substrate is connected to the heat-conducting cover plate, wherein the second gap corresponds to each first gap.

[0036] In a specific embodiment, before fixing the support portion to the substrate, the method further comprises:

[0037] A recess is formed on the supporting portion for cooperating with the substrate to form a second gap.

[0038] In a specific embodiment, a support portion is provided on the surface of the heat-conducting cover plate having the filling area, wherein the support portion surrounds at least one receiving groove corresponding to the filling area, and an end of the support portion facing away from the heat-conducting cover plate has a recess;

[0039] Mounting a heat-conducting cover plate on a side of at least one chip facing away from the substrate comprises:

[0040] The heat-conducting cover plate is placed on a side of at least one chip facing away from the substrate, and one end of the support portion away from the heat-conducting cover plate is connected to the substrate, wherein the recess cooperates with the substrate to form a second gap corresponding to each first gap.

[0041] In a specific embodiment, before placing the heat conductive cover plate on the side of at least one chip facing away from the substrate, the method further includes:

[0042] A recess is formed at one end of the support portion facing away from the heat-conducting cover plate.

[0043] In a specific embodiment, before mounting the heat conductive cover plate on the side of at least one chip facing away from the substrate, the method further includes:

[0044] A thermal interface material layer is formed on the surface of each chip facing away from the substrate.

[0045] Since the thermal interface material layer is covered by the filling material, it is prevented from reacting with components in the air and deteriorating, thereby ensuring the heat dissipation stability of the chip and improving the performance of the electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1a A schematic diagram of a packaging structure is shown;

[0047] Figure 1b Express Figure 1aThe schematic diagram of the package structure after cooling and deformation is shown;

[0048] Figure 2 A schematic diagram showing an application scenario of the packaging structure provided by an embodiment of the present application;

[0049] Figure 3a A schematic diagram showing a packaging structure provided by an embodiment of the present application;

[0050] Figure 3b Expressed Figure 3a Bottom view of the middle radiator;

[0051] Figure 3c Express Figure 3a A side view of the radiator in FIG.

[0052] Figure 3d Expressed Figure 3a The distribution of adhesive on the radiator;

[0053] Figure 4a A schematic diagram showing another packaging structure provided by an embodiment of the present application;

[0054] Figure 4b Expressed Figure 4a Bottom view of the middle radiator;

[0055] Figure 5a A schematic diagram showing another packaging structure provided by an embodiment of the present application is shown;

[0056] Figure 5b Expressed Figure 5a A bottom view of the heat sink in the package structure shown;

[0057] Figure 6 A schematic diagram showing the cooperation between the packaging structure and the circuit board in the electronic device provided by the embodiment of the present application;

[0058] Figure 7a A schematic diagram showing another packaging structure provided by an embodiment of the present application;

[0059] Figure 7b Express Figure 7a Bottom view of the middle radiator;

[0060] Figure 7c A schematic diagram showing another packaging structure provided by an embodiment of the present application;

[0061] Figure 7d Express Figure 7c Bottom view of the middle radiator;

[0062] Figure 8aFIG2 shows a schematic structural diagram after executing step S110 in the chip packaging method provided in an embodiment of the present application;

[0063] Figure 8b FIG2 shows a schematic diagram of the structure after executing step S120 in the chip packaging method provided in an embodiment of the present application;

[0064] Figure 8c FIG2 shows a schematic structural diagram after executing step S210 in the chip packaging method provided in an embodiment of the present application;

[0065] Figure 8d FIG2 shows a schematic diagram of the structure after executing step S220 in the chip packaging method provided in an embodiment of the present application;

[0066] Figure 8e FIG2 shows a schematic diagram of the structure after executing step S300 in the chip packaging method provided in an embodiment of the present application;

[0067] Figure 8f FIG4 shows a schematic structural diagram after executing step S410 in the chip packaging method provided in an embodiment of the present application;

[0068] Figure 8g FIG4 shows a schematic structural diagram after executing step S500 in the chip packaging method provided in an embodiment of the present application;

[0069] Figure 9a FIG2 shows a schematic diagram of the structure after executing step S221 in the chip packaging method provided in an embodiment of the present application;

[0070] Figure 9b FIG2 shows a schematic diagram of the structure after executing step S222 in the chip packaging method provided in an embodiment of the present application;

[0071] Figure 10a FIG2 shows a schematic diagram of the structure after executing step S230 in the chip packaging method provided in an embodiment of the present application;

[0072] Figure 10b FIG2 shows a schematic structural diagram after executing step S240 in the chip packaging method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0074] Figure 1a A schematic diagram of a packaging structure is shown. Figure 1b The schematic diagram shows the deformation of the package structure after cooling. Figure 1aChip 05 is electrically connected to the pads on substrate 02 via solder balls 06. Heat sink 01 includes a thermally conductive cover plate 011 and an annular support portion 012. Thermally conductive cover plate 011 covers the side of chip 05 facing away from substrate 02. Annular support portion 012 is located on the side of thermally conductive cover plate 011 facing substrate 02 and surrounds chip 05. Annular support portion 012 is connected to thermally conductive cover plate 011 and to substrate 02 via adhesive 03. A thermal interface material layer 04 is placed between chip 05 and thermally conductive cover plate 011. Thermal interface material layer 04 is typically made of metallic indium. When exposed to air, it is easily degraded by oxygen and moisture in the air, such as oxidation or sulfurization, which affects its thermal conductivity.

[0075] In addition, since the substrate 02 needs to be installed on the circuit board through high-temperature methods such as reflow soldering, the metal indium will melt due to the heat and flow out from between the chip 05 and the thermal cover 011, affecting the heat dissipation of the chip 05.

[0076] In addition, the thermal expansion coefficient of the substrate 02 is larger than that of the chip 05. Therefore, after the chip 05 is mounted on the substrate 02 through the solder balls 06 at a high temperature (usually around 150°C), please refer to Figure 1b When the package structure cools to room temperature (generally around 25°C), the substrate 02 shrinks significantly, and the edge of the chip 05 will be pulled toward the middle by the substrate 02, causing the middle of the chip 05 to bulge, the edge to sink, and a gap c1 to form between the chip 05 and the thermal interface material layer 04. Good contact cannot be maintained between the chip 05 and the thermal interface material layer 04, resulting in poor heat dissipation of the chip 05.

[0077] In order to solve the above technical problems, an embodiment of the present application provides a packaging structure.

[0078] To facilitate understanding of the packaging structure provided in the embodiments of the present application, the application scenario of the packaging structure provided in the embodiments of the present application is first explained. The packaging structure is applied to electronic devices such as servers, computers, tablet computers and mobile phones. Figure 2 The schematic diagram of the application scenario of the packaging structure provided by the embodiment of the present application is shown in FIG. Figure 2The package structure includes a substrate 10, a chip 20, a heat sink 30, and a thermal interface material layer 40. The chip 20 can be a bare chip (i.e., a die) and is mounted on one surface of the substrate 10 by means of solder balls or the like. The heat sink 30 covers the surface of the chip 20 facing away from the substrate 10. The thermal interface material layer 40 is filled between the heat sink 30 and the chip 20. The heat from the chip 20 is transferred to the heat sink 30 through the thermal interface material layer 40, and heat is dissipated through the heat sink 30. The surface of the substrate 10 facing away from the chip 20 is mounted on a circuit board 2 by means of solder balls (reference numeral 50), or the like. The circuit board 2 can be a printed circuit board (PCB) or other types of circuit boards.

[0079] The packaging structure provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0080] Figure 3a A schematic diagram showing a packaging structure provided by an embodiment of the present application is shown. First, refer to Figure 3a The packaging structure includes a substrate 10, a chip 20, a heat sink 30 and a thermal interface material layer 40; wherein the heat sink 30 includes a heat-conducting cover plate 301, a support portion 303 and a surrounding wall 302. The materials of the heat-conducting cover plate 301, the support portion 303 and the surrounding wall 302 can all be copper, aluminum or copper-aluminum alloy, but the heat-conducting cover plate 301 is not limited to the above materials, as long as it is a plate-shaped structure made of a material with good thermal conductivity; the chip 20 has a top surface a, a bottom surface b and a side surface c, the top surface a and the bottom surface b are arranged opposite to each other, and the side surface c connects the top surface a and the bottom surface b. Among the above surfaces of the chip 20, the "top surface" means the surface of the chip facing away from the substrate during packaging, the "bottom surface" means the surface of the chip facing the substrate during packaging, and the "side surface" means the surface connecting the above "top surface" and "bottom surface"; the "substrate" means a plate-shaped structure that can support the chip 20, which has a circuit that can connect from the surface facing the chip 20 to the surface facing away from the chip 20. It can be a circuit board or other plate material.

[0081] Continue to refer Figure 3a, the bottom surface b of the chip 20 is mounted on the surface of the substrate 10 facing the heat conducting cover plate 301 in the form of FCBGA (Flip Chip Ball Grid Array). Specifically, the chip 20 is electrically connected to the pads on the surface of the substrate 10 through a plurality of solder balls 50 distributed in an array. An underfill 60 is filled between the bottom surface b of the chip 20 and the substrate 10. The underfill 60 wraps the solder balls 50. The underfill 60 can be a material commonly used in the art such as epoxy resin. The underfill 60 can effectively improve the mechanical strength of the solder balls 50 and make the connection between the solder balls 50 and the chip 20 and the substrate 10 more solid. However, this is only exemplary. The chip 20 can also be mounted on the substrate 10 in other ways, for example, in the form of FCLGA (Flip Chip Land Grid Array).

[0082] Figure 3b Expressed Figure 3a Bottom view of the radiator 30 (along Figure 3a View from P1 in the figure). Figure 3b One surface of the heat-conducting cover plate 301 has a filling area S1, which is illustratively located in the middle of the surface of the heat-conducting cover plate 301 facing the substrate 10. A chip heat-conducting area S2 is also provided inside the filling area S1, wherein the area of the filling area S1 is larger than that of the chip heat-conducting area S2. The surrounding wall 302 extends along the edge of the filling area S1 and is connected to the heat-conducting cover plate 301. Any section of the surrounding wall 301 remains continuous, so that the surrounding wall 301 and the filling area S1 form a receiving groove K1. The so-called "receiving groove" refers to a groove-like structure that can accommodate liquid material and restrict its flow, and has a bottom surface and side surfaces arranged along the edge of the bottom surface. The shape of the bottom surface is not limited to Figure 3a The square in the figure can also be a closed shape such as a rectangle, a circle or an ellipse; the support portion 303 and the surrounding wall 301 are arranged on the same surface of the heat-conducting cover plate 301 and are connected to the heat-conducting cover plate 301, and the support portion 303 is located on the periphery of the surrounding wall 301 and is arranged around the surrounding wall 301.

[0083] Back to Figure 3aThe heat-conducting cover plate 301 is located on the side of the chip 20 away from the substrate 10, the opening of the receiving groove K1 faces the substrate 10, and a part of the chip 20 is also received in the receiving groove K1. The surface of the support portion 303 away from the heat-conducting cover plate 301 is bonded to the substrate 10 by adhesive 3031, etc. The adhesive 3031 can be selected from one or more of silicone elastomer adhesive, epoxy adhesive, modified epoxy resin and modified silicone adhesive. The top surface a of the chip 20 is arranged opposite to the chip heat conduction area S2 of the heat conductive cover 301. The so-called "relative arrangement" here means that the orthographic projection of the top surface a on the surface of the heat conductive cover 301 facing the substrate 10 coincides with the heat conductive area S2. The thermal interface material layer 40 is filled between the chip heat conductive area S2 and the top surface a of the chip 20. The thermal interface material layer 40 has a first surface and a second surface opposite to each other, wherein the first surface contacts the heat conductive cover 301 and the second surface contacts the chip 20. The material of the thermal interface material layer 40 is illustratively metallic indium. The thickness of the thermal interface material layer 40 is between 25 and 200 microns, for example, it can be 25 microns, 50 microns, 60 microns, 80 microns, 100 microns, 120 microns, 150 microns, 180 microns and 200 microns, etc. The above introduction to the thermal interface material layer 40 is merely exemplary. For example, in addition to metallic indium, its material can also be indium / silver, tin / silver / copper, or indium / tin / bismuth and other metal materials with high thermal conductivity, or non-metallic materials with high thermal conductivity. Moreover, in the receiving groove K1, a portion of the side surface c of the chip 20 is arranged opposite to the surrounding wall 301, that is, a portion of the chip 20 extends into the receiving groove K1, and a filling material 70 is filled between the side surface c of the chip 20 and the surrounding wall 301. The so-called "filling material" here refers to a viscous material with a certain hydrophobicity, and the so-called "viscous material" refers to a material that can combine two components together through its own adhesion. The filling material 70 covers a portion of the side surface c of the chip 20, wherein the filling material 70 can be one or more insulating materials such as silicone, polyolefin resin, epoxy resin, modified epoxy resin, silicone resin and modified silicone resin. Since the filling material 70 is an insulating material, it can prevent the pins of the chip 20 from short-circuiting. The filling material 70 completely covers the side of the thermal interface material layer 40. The "side" of the thermal interface material layer 40 refers to the surface connecting the first surface (the surface in contact with the heat-conducting cover plate 301) and the second surface (the surface in contact with the chip 20) of the thermal interface material layer 40. This prevents components in the air from damaging and deteriorating the thermal interface material layer 40. For example, when the thermal interface material layer 40 is metal indium, moisture and oxygen in the air are blocked by the filling material 70 and cannot contact the thermal interface material layer 40, and the thermal interface material layer 40 will not be oxidized or sulfurized. As mentioned above, one of the functions of the receiving groove K1 is to limit the filling material 70 when pouring it into the receiving groove K1, and prevent the filling material 70 from flowing before the filling material 70 solidifies.

[0084] Figure 3c Express Figure 3a The side view of the heat sink 30 in FIG. Figure 3b P2 direction view in, refer to Figure 3c , wherein the support portion 303 is provided with a recess U1, which is formed from the surface of the support portion 303 away from the heat-conducting cover plate 301 inwardly in the direction of the heat-conducting cover plate 301. The function of the recess U1 is that when the packaging structure is formed, the recess U1 cooperates with the substrate 10 to form a second gap c3 (reference Figure 3a ), with the opening of the receiving groove K1 facing upward, pour the filling material 70 into the receiving groove K1 through the second gap c3 through a pipe or the like (see Figure 3a ), without the need to drill holes in the heat-conducting cover plate 301 to pour the filling material 70; in addition, the above-mentioned recess U1 also has the function of regulating the air pressure in the limited space surrounded by the radiator 30 and the substrate 10 and the outside air pressure, so as to prevent the air in the above-mentioned limited space from expanding and contracting due to temperature changes, causing pressure changes and affecting chip performance; however, it should be understood that the form of the recess U1 is not limited to the form of the collapse of the above-mentioned support portion 303, and the support portion may also include a plurality of support legs arranged at intervals, and the gaps between the support legs are used as the recess of the above-mentioned support portion, as long as the pipeline for pouring the filling material 70 can pass through the support portion 303 to pour the filling material 70 into the accommodating groove K1.

[0085] Figure 3d Expressed Figure 3a For the distribution of adhesive 3031 on the heat sink 30, please refer to Figure 3d The adhesive 3031 does not completely cover the surface of the support portion 303 facing away from the heat-conducting cover plate 301. Instead, a gap G1 is left to better maintain the air in the limited space enclosed by the heat sink 30 and the substrate 10 in communication with the outside air. This prevents the air in the limited space from expanding and contracting due to temperature fluctuations, causing pressure changes that could affect the performance of the chip 20. However, since the recess U1 is reserved to regulate air pressure, the gap in the adhesive 3031 can be omitted.

[0086] Continue back Figure 3a , along the thickness direction of the heat-conducting cover plate 301 (parallel to the P1 direction), the height h1 of the support portion 303 is greater than the height h2 of the surrounding wall 302, so that a first gap c2 communicating with the receiving groove K1 is formed between the opening edge of the receiving groove K1 and the substrate 10. The so-called "opening edge" in the embodiment of the present application refers to an annular area with a certain width formed by the side of the receiving groove away from the annular side of the bottom surface extending toward the periphery of the receiving groove. For details, please refer to Figure 3aThe middle surrounding wall 302 faces the surface e of the substrate 10 (refer to the bold black line position indicated by e in the figure). Other forms of opening edges will be listed later, such as Figure 4a and Figure 5a surface e in the receiving groove K1; when the filling material 70 is poured into the receiving groove K1 by using a pipe, the first gap c2 can allow the pipe to pass through and extend to the opening or the interior of the receiving groove K1; in order to take into account the requirements of pouring the filling material 70 into the receiving groove K1 by the pipe, and the depth of the receiving groove K1 (to ensure the filling amount of the filling material 70), the width of the first gap c2 (the dimension in the P1 direction) ranges from 30μm to 2mm, for example, it can be 30μm, 70μm, 100μm, 200μm, 300μm, 400μm, 600μm, 750μm, 1mm, 1.5mm, 1.8mm or 2mm. At the same time, due to the presence of the first gap c2, the substrate 10 is not secured by the surrounding wall 302. The thermal expansion coefficients of the substrate 10 and the thermally conductive cover plate 301 differ. When the temperature changes, the thermally conductive cover plate 301 and the substrate 10 expand and contract at different rates. The stress generated in the substrate 10 due to the temperature difference can be released through expansion and contraction. If the substrate 10 were secured by the surrounding wall 302, this stress would not be fully released, reducing the lifespan of the substrate 10. Furthermore, maintaining the first gap c2 between the surrounding wall 302 and the substrate 10 helps prevent contact between the surrounding wall 302 and the substrate 10, which would result in the surrounding wall enclosing the chip 20 in a sealed space. The gas pressure in this sealed space would change with temperature fluctuations, affecting the performance of the chip 20.

[0087] Figure 4a A schematic diagram showing another packaging structure provided by an embodiment of the present application is shown. Figure 4b Expressed Figure 4a Bottom view of the middle radiator; Figure 4a and Figure 4b The heat conductive cover plate 30 shown is Figure 3bThe difference between the heat-conducting cover plate 30 shown in the figure is that an extension wall 304 is provided along the opening edge of the accommodating groove K1 (i.e., the end face e of the surrounding wall 302 away from the heat-conducting cover plate 301, which can be referred to as the bold black line position indicated by e in the figure). The end of the extension wall 304 away from the surrounding wall 302 is connected to the substrate 10, wherein the side wall 3041 of the extension wall 304 close to the recess U1 has a hollow U2, which extends from a part of the end face e of the surrounding wall 302 to the substrate 10. The hollow U2 is shaped A first gap c2 is formed between the opening edge of the receiving groove K1 and the substrate 10. The hollow U2 corresponds to the recess U1. "Corresponding" here means that the orthographic projection of the recess U1 on a reference plane (denoted as w) partially or completely overlaps with the orthographic projection of the hollow U2 on the reference plane w. The plane of the side wall 3041 of the extended wall 304 where the hollow U2 is located, facing the support portion 303, is used as the reference plane w. Thus, the second gap c3 can correspond to the first gap c2. When the filling material 70 is poured into the receiving groove K1 using a pipe, the first gap c2 allows the pipe to pass through and extend into the opening or interior of the receiving groove K1. At the same time, it also helps to maintain the balance of pressure between the confined space enclosed by the extended wall 304 and the surrounding wall 302 and the external air pressure, preventing the air pressure in the confined space from changing due to temperature fluctuations.

[0088] Return to the embodiment of this application Figure 3a Since the filling material 70 is a viscous material such as silicone and polyolefin resin, the filling material 70 can firmly fix the side c of the chip 20 to the surrounding wall 302 and the thermal conductive cover 301 respectively, thereby alleviating or even preventing the edge of the chip 20 from being caused by the gap between the thermal interface material layer 40 and the chip 20 due to the shrinkage of the substrate 10 (refer to Figure 1b The gap c1 in the chip 20 is eliminated, thereby ensuring good contact between the chip 20 and the thermal interface material layer 40, thereby achieving good heat dissipation for the chip 20. However, it should be understood that the material of the filler material 70 is not limited to the above materials; it only needs to ensure that the filler material 70 has sufficient viscosity and contacts at least a portion of the side surface c of the chip 20.

[0089] Furthermore, when selecting the material combination of the filler material 70 and the thermal interface material layer 40, the melting point of the filler material 70 can be higher than the melting point of the thermal interface material layer 40, and the melting point of the filler material 70 can also be higher than the temperature near the solder joint during reflow soldering. For example, the filler material 70 can be silicone and the thermal interface material layer 40 can be metallic indium. When the substrate 10 is mounted on the substrate 10 via FCBGA, a reflow soldering process is required, and the temperature of the metallic indium is heated to above 200°C. Due to its low melting point (generally approximately 156.61°C), the metallic indium melts, but the silicone has a high melting point and does not melt. Therefore, although the metallic indium melts, its flow range is still limited by the silicone, maintaining good thermal contact between the chip 20 and the thermally conductive cover plate 301. Similar effects can be achieved with other material combinations where the melting point of the filler material 70 can be higher than the melting point of the thermal interface material layer 40.

[0090] It should be noted that the filling material 70 can fill the entire receiving groove K1, or it can fill part of the space within the receiving groove K1. Even if the filling material 70 does not contact the side c of the chip 20, as long as it can cover the side of the thermal interface material layer 40, it can also achieve the effect of blocking the contact between air and the thermal interface material layer 40.

[0091] It should be noted that, while the heat-conducting cover plate 301, the support portion 303, and the surrounding wall 302 are all made of the same material and are integrally formed, this is merely exemplary. As long as the heat-conducting cover plate 301 has good thermal conductivity, copper, aluminum, copper-aluminum alloy, or other materials with high thermal conductivity can be used, and the support portion 303 and surrounding wall 302 can be made of a different material from the heat-conducting cover plate 301. Furthermore, regardless of whether the heat-conducting cover plate 301, the support portion 303, and the surrounding wall 302 are made of the same material, the support portion 303 and the surrounding wall 302 can each be a separate structure from the heat-conducting cover plate 301, i.e., the support portion 303 and the heat-conducting cover plate 301 are not integrally formed, and the surrounding wall 302 and the heat-conducting cover plate 301 are also not integrally formed; for example, the support portion 303 and the surrounding wall 302 can each be an independent annular structure. When the heat-conducting cover plate 301 and the supporting portion 303 are made of the same material, the two can be integrally formed; similarly, when the heat-conducting cover plate 301 and the surrounding wall 302 are made of the same material, the two can be integrally formed.

[0092] In addition, it should be understood that the method of forming the receiving groove K1 on the heat-conducting cover is not limited to Figure 3b The accommodating groove K1 is formed by the surrounding wall 302 , and other forms may be adopted as long as the opening of the accommodating groove faces the substrate 10 . Figure 5a Schematic diagram showing another packaging structure provided by an embodiment of the present application, Figure 5b Expressed Figure 5a The bottom view of the heat sink 30 in the package structure shown in FIG. Figure 5a and Figure 5b,and Figure 3a Compared with the corresponding embodiment of the package structure shown, Figure 5a The difference between the package structures shown is that the filling area S1 of the heat-conducting cover plate 301 is concave in the direction away from the substrate 10, forming a groove with an opening facing the substrate 10, and the groove serves as the receiving groove K1. There are many ways to form the groove, such as etching, stamping or cutting; the matching method of the chip 20, the thermal interface material layer 40, the filling material 70 and the receiving groove K1 can be referred to. Figure 3a It should be noted that a first gap c2 is formed between the opening edge e of the receiving groove K1 and the substrate 10 for a pipe to pass through for pouring the filling material 70 into the receiving groove K1. Figure 5a The surface of the middle heat-conducting cover plate 301 facing the substrate 10 is located in an annular area around the opening of the receiving groove K1. The specific location can be referred to the bold black line position indicated by e in the figure. In addition, it should be noted that Figure 5a and Figure 5b In the figure, the filling area S1 (ie, the bottom surface of the receiving groove K1 ) is still regarded as the surface of the heat-conducting cover plate 301 facing the substrate 10 .

[0093] In the packaging structures of the above embodiments, each heat-conducting cover plate is formed with only one receiving groove to package one chip, but the present invention is not limited to this form. Alternatively, the heat-conducting cover plate may have multiple filling areas, each of which forms a corresponding receiving groove, and multiple chips may be packaged on the substrate.

[0094] Figure 7a A schematic diagram showing another packaging structure provided by an embodiment of the present application is shown. Figure 7b Express Figure 7a For bottom view of the middle radiator 30 (view from P1 direction), please refer to Figure 7a and Figure 7b ,and Figures 3a to 4b The difference between the packaging structures shown is that the heat sink 30 includes a heat-conducting cover plate 301, a support portion 303 and a plurality of (four in the figure) surrounding walls 302. The surface of the heat-conducting cover plate 301 facing the substrate 10 has a plurality of filling areas S1. Each surrounding wall 302 is arranged along the corresponding filling area S1. Each surrounding wall 302 and the filling area S1 surrounded by it form a receiving groove K1. The various parts of each receiving groove K1 can be referred to in the following description. Figures 3a to 4bThe arrangement of the receiving groove K1 in the corresponding embodiment. A plurality of chips 20 corresponding to the plurality of receiving grooves K1 are provided on the substrate 10, that is, each chip 20 cooperates with a receiving groove K1, each receiving groove K1 corresponds to a chip 20, and a thermal interface material layer 40 is filled between each chip 20 and the chip heat conduction area S1 on the bottom surface of the corresponding receiving groove K1, and each receiving groove K1 is filled with a filling material 70. The arrangement and possible deformation of each group of chips 20, thermal interface material layer 40, filling material 70 and receiving groove K1 can be referred to. Figures 3a to 4b In the corresponding embodiment, the corresponding arrangement and related deformation of a group of chips 20, thermal interface material layer 40, filling material 70 and receiving groove K1. For example, the formation of each receiving groove K1 can also be Figure 5a and Figure 5b Each accommodating groove K1 has a concave depression U1 adjacent to it on the supporting portion 303. Thus, each heat sink 30 can maintain effective thermal contact with multiple chips 20 at the same time.

[0095] Each receiving slot K1 is not limited to cooperate with only one chip. Figure 7c A schematic diagram showing another packaging structure provided by an embodiment of the present application is shown. Figure 7d Express Figure 7c Bottom view of the middle radiator; combined Figure 7c and Figure 7d ,and Figures 3a to 4b The difference between the corresponding embodiments is that there are multiple (4 in the figure as an example) chip heat conduction areas S2 spaced apart within each filling area S1, wherein each chip heat conduction area S2 is coordinated with a chip 20, and a thermal interface material layer 40 is filled between each chip 20 and the corresponding chip heat conduction area S2, and the accommodating groove K1 is filled with a filling material 70. The filling depth of the filling material 70 can be adjusted as needed. For details, please refer to the description of the filling material 70 in the previous embodiments. It can cover part or all of the side c of each chip 20, or only cover the side of each thermal interface material layer 40.

[0096] In addition, a plurality of receiving grooves may be provided on the surface of the heat conducting cover plate of the heat sink facing the substrate, and each receiving groove covers one or more chips.

[0097] Based on the same inventive concept, an embodiment of the present application provides an electronic device, which can be a server, a computer, a tablet computer, a mobile phone, etc. The electronic device includes a circuit board 2 and a packaging structure provided in the above embodiment. The substrate in the packaging structure is fixed to the surface of the circuit board through FCBGA or FCLGA, etc., and is electrically connected to the solder pads on the surface of the circuit board. Figure 6Schematic diagram showing the cooperation between the packaging structure 1 and the circuit board 2 in the electronic device provided in the embodiment of the present application. Figure 6 The substrate 10 of the package structure 1 is fixed and electrically connected to the circuit board 2 by means of FCBGA. More specifically, the pins of the substrate 10 are electrically connected to the pads on the substrate 10 through the solder balls 80. Figure 3a The filling material 70 in the receiving groove K1 wraps around the sides of the thermal interface material layer 40, thereby preventing damage such as oxidation and sulfurization of the thermal interface material layer 40 by external air, ensuring good thermal contact between the chip 20 and the heat-conducting cover plate 301, and facilitating sufficient heat dissipation from the chip 20. The deformation and effects of the package structure 1 can refer to the package structure provided in the above embodiment.

[0098] Based on the same inventive concept, an embodiment of the present application also provides a chip packaging method for forming the packaging structure provided by the above embodiment.

[0099] For example, the thermal interface material layer is made of metallic indium and the filling material is made of liquid silicone or polyolefin resin. Figures 8a to 8g The figure shows a schematic diagram of the chip packaging method after each step.

[0100] The method includes:

[0101] S100: Mount the chip on the surface of the substrate.

[0102] Specifically, first, execute step S110, as shown in FIG. Figure 8a As shown, solder balls 50 are deposited on the pads on the bottom surface b of the chip 20, and the solder balls 50 are connected to the corresponding pads on the substrate 10 by reflow soldering;

[0103] Then, execute step S120, as shown in FIG. Figure 8b As shown, the gaps between the solder balls 50 are filled with bottom filler 60. Specifically, epoxy resin is applied to the edge of the chip 20 by capillary action, and the epoxy resin penetrates between the bottom surface b of the chip 20 and the substrate 10 and fills the gaps between the solder balls 50.

[0104] S200 , installing a heat-conducting cover plate on a side of the chip facing away from the substrate.

[0105] Specifically, first, execute step S210, refer to Figure 8c A metal indium sheet 40 is placed on the top surface a of the chip 20 , and adhesive 3031 is applied to the surface of the substrate 10 at a position corresponding to the support portion 303 of the heat sink 30 .

[0106] Next, execute step S220, refer to Figure 8d , install the radiator 30, the structure of the radiator 30 can refer to Figure 3a and Figure 3b The structure of the heat sink 30. The opening of the heat sink 30 is facing the substrate 10, the chip heat conduction area S1 is pressed onto the metal indium sheet 40, the support part 303 is pressed onto the adhesive 3031, and the chip 20 is partially placed in the receiving groove K1. A first gap c2 is formed between the surface e of the wall 302 facing the substrate 10 (i.e., the opening edge of the receiving groove K1) and the substrate 10, and the recess U1 cooperates with the substrate 10 to form a second gap c3; then, the metal indium sheet 40 and the adhesive 3031 are cured at high temperature. The high-temperature curing process can be as follows: first heat it to an appropriate temperature to cure the adhesive first. At this time, the temperature can be, for example, about 125°C, and then heat it to 160°C to 170°C to melt the metal indium sheet, and then reduce the temperature to about 150°C to solidify the melted metal indium to form a thermal interface material layer 40.

[0107] S300 , turning over the substrate so that the opening of the receiving groove faces upward.

[0108] Specifically, refer to Figure 8e The substrate 10, the heat sink 30 and the chip 20 are turned over 180 degrees as a whole so that the opening of the receiving groove K1 faces upward, so that when the filling material 70 is injected into the receiving groove K1 in the next step, the filling material 70 can be confined in the receiving groove K1.

[0109] S400 , injecting a filling material into the receiving groove through the second gap and solidifying the filling material.

[0110] Specifically, perform step S410, please refer to Figure 8f The pipe 90 passes through the second gap c3 and extends to above the opening of the receiving tank K1. The pipe 90 injects the liquid filling material 70 into the receiving tank K1.

[0111] Next, step 410 is performed to solidify the filling material 70 to form a Figure 3a The package structure shown.

[0112] S500, planting balls on a surface of the substrate facing away from the chip.

[0113] Specifically, refer to Figure 8g , multiple solder balls 80 are implanted on the pads on the surface of the substrate 10 facing away from the chip 20 .

[0114] It should be noted that in the above step S220, when the radiator 30 is installed, the support portion 303 and the heat-conducting cover plate 301 in the radiator 30 are an integral structure, or, although they are split structures, they are pre-bonded and fixed; wherein, "integrated structure" refers to a structure formed in one piece, and "split structure" refers to a structure in which different structures are first formed separately and then spliced together by welding or bonding. However, this is only exemplary. When the support portion 303 and the heat-conducting cover plate 301 are split structures, the support portion 303 can be an independent ring structure. In this case, the above step S220 can be decomposed into at least the following two steps:

[0115] S221, Reference Figure 9a First, the support portion 303 is pressed onto the adhesive 3031 to fix the support portion 303 to the substrate 10 . The recess U1 cooperates with the substrate 10 to form a second gap c3 , wherein the support portion 303 is arranged around the chip 20 .

[0116] S222, Reference Figure 9b The heat-conducting cover plate 303 with the receiving groove K1 is placed on the side of the chip 20 facing away from the substrate 10, and the heat-conducting cover plate 301 is fixedly connected to the end of the support portion 303 facing away from the substrate 10 using an adhesive or the like. The manner in which the chip 20 and the thermal interface material layer 40 respectively cooperate with the receiving groove K1, as well as the manner in which the first gap c2 and the second gap c3 cooperate, are all described in the aforementioned step S200.

[0117] Furthermore, the surrounding wall 302 may be integral with the heat-conducting cover plate 303 or may be a separate structure, and prior to executing step S222, the surrounding wall 302 is fixed to the surface of the heat-conducting cover plate 303. The support portion 303 with the recess U1 in step S221 may be directly cast, or, prior to step S221, the recess U1 may be formed on the surface of the annular support portion 303 for connection to the substrate 10 by etching or cutting.

[0118] The radiator 30 may be provided with a receiving groove K1 when purchased, or may further include step S150 between step S100 and step 200: setting a surrounding wall 302 along the edge of the filling area S1 of the heat-conducting cover plate 301. For example, the surrounding wall 302 may be fixed to the surface of the heat-conducting cover plate 301 by bonding or welding, and the surrounding wall 302 and the filling area S1 surrounded by it form a receiving groove K1.

[0119] Alternatively, when the receiving groove K1 is as follows Figure 5a In the case of a form of being recessed in the heat-conducting cover plate 301, step S150 is correspondingly changed to: forming a recessed groove in the substrate 301 at a position corresponding to the filling area S1 by etching, cutting or punching, and the recess constitutes an accommodating groove K1.

[0120] The step S150 may also be other ways to form the receiving groove K1.

[0121] Furthermore, the recess U1 on the support portion 303 may be processed when it is obtained, or may be formed by cutting or etching before step S200.

[0122] In addition, when forming Figure 4a When the package structure shown is used, step S200 can also be replaced by the following method:

[0123] First, execute step S230, refer to Figure 10a : The extension wall 304 is fixed to the substrate 10 by bonding or other means, and the extension wall 304 surrounds the chip 20. A surrounding wall 302 is provided at the end of the extension wall 304 facing away from the substrate 10. The surrounding wall 302 and the extension wall 304 can be an integrated structure or a spliced split structure. The extension wall 304 has a hollow U2, and the hollow U2 extends from the end of the extension wall 304 facing away from the surrounding wall 302 to the surrounding wall 302. When the extension wall 304 is fixed to the substrate 10, the extension wall 304 can be regarded as a ring with a notch (hollow U2), and the hollow U2 cooperates with the substrate 10 to form a first gap c2; accordingly, the support part 303 is also fixed to the substrate 10, wherein the support part 303 is arranged around the surrounding wall 302, and the recess U1 of the support part 303 cooperates with the substrate 10 to form a second gap c3, and the second gap c3 corresponds to the first gap c2.

[0124] Then, execute step S240 again, refer to Figure 10b : The heat-conducting cover plate 301 is placed on the side of the chip 20 facing away from the substrate 10, and the edge of the filling area S1 of the heat-conducting cover plate 301 is connected to the surrounding wall 302 by bonding or other means. The surrounding wall 302 and the filling area S1 form a receiving groove K1; accordingly, the support portion 303 and the heat-conducting cover plate 301 are fixed by bonding or other means.

[0125] It should be noted that in step S230 , the support portion S303 may not be fixed to the substrate 10 first, but may be fixed to the heat conductive cover 301 first, and then in step S240 , the support portion S303 is fixed to the substrate 10 .

[0126] For other beneficial effects of this method, please refer to the description of the relevant effects in the embodiment of the above packaging structure.

[0127] It should be noted that the above method is merely exemplary, and possible deformations of various parts in the packaging structure (including but not limited to materials, connection methods and structural forms) can refer to the introduction of the packaging structure in the aforementioned embodiments, and appropriate adjustments can be made to the chip packaging method.

[0128] For example, when the thermal cover is used to dissipate heat for multiple chips, you can refer to Figures 7a to 7d In the form of a packaging structure, in step S200, it is only necessary to match each receiving slot with a chip.

[0129] For another example, when each heat-conducting cover plate has multiple receiving slots, Figure 7a and Figure 7b In the form of the corresponding packaging structure, in step S400 , the filling material 70 may be poured into the corresponding receiving groove K1 through each second gap c3 , or the filling material 70 may be poured into the multiple receiving grooves K1 through only one second gap c3 .

[0130] When a slot covers multiple chips, refer to Figure 7c and Figure 7d In the form of the corresponding packaging structure, in step S400 , the filling material 70 is poured into only one receiving groove K1 , and the filling material 70 can respectively cover the side surfaces c of different chips 20 in the receiving groove K1 and the corresponding thermal interface material layer 40 .

[0131] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A packaging structure, characterized in that: include: A substrate, a heat-conducting cover plate and at least one chip, wherein the heat-conducting cover plate is arranged on a side of the at least one chip facing away from the substrate; The surface of the heat-conducting cover plate facing the substrate has at least one filling area, each of the filling areas corresponds to one or more chips, each of the filling areas has a receiving groove opening toward the substrate, a thermal interface material layer is filled between each chip and the bottom surface of the corresponding receiving groove, and each of the receiving grooves is filled with the filling material, wherein, in each of the receiving grooves, the filling material wraps around the side surface of the thermal interface material layer; a portion of the chip is received in the receiving groove; A first gap communicating with the accommodating groove is defined between at least a portion of an opening edge of each accommodating groove and the substrate.

2. The packaging structure according to claim 1, wherein: A surrounding wall connected to the heat-conducting cover plate is provided along the edge of each filling area, and each surrounding wall and the corresponding filling area form a receiving groove.

3. The packaging structure according to claim 2, wherein: A first gap is formed between each of the surrounding walls and the substrate.

4. The packaging structure according to claim 3, wherein: The width of each of the first gaps is between 30 μm and 2 mm.

5. The packaging structure according to claim 2, wherein: An extension wall is connected between one end of each surrounding wall away from the heat-conducting cover plate and the substrate. The extension wall has a hollow extending from the surrounding wall to the substrate, and the hollow forms the first gap.

6. The packaging structure according to any one of claims 2 to 5, characterized in that: Each of the surrounding walls and the heat-conducting cover plate is a split structure.

7. The packaging structure according to any one of claims 2 to 5, characterized in that: Each of the surrounding walls and the heat-conducting cover plate is an integrated structure.

8. The packaging structure according to claim 1, wherein: Each of the filling areas is concave inwardly in a direction away from the substrate to form an accommodating groove.

9. The packaging structure according to any one of claims 1 to 5 and 8, characterized in that: The packaging structure further includes a supporting portion, which is disposed between the substrate and the heat-conducting cover plate and is connected to the substrate and the heat-conducting cover plate respectively; The supporting portion surrounds the receiving groove corresponding to the at least one chip, wherein a second gap corresponding to each of the first gaps is formed between a portion of the supporting portion and the substrate.

10. The packaging structure according to claim 9, wherein: The support portion and the heat-conducting cover plate are split structures.

11. The packaging structure according to any one of claims 1 to 5 and 8, characterized in that: In each of the containing grooves, the melting point of the filling material is higher than the melting point of each of the thermal interface material layers.

12. The packaging structure according to claim 11, wherein: In each of the receiving slots, The material of each thermal interface material layer is indium, indium / silver, tin / silver / copper, or indium / tin / bismuth; The filling material is made of one or more of silica gel, polyolefin resin, epoxy resin, modified epoxy resin, silicone resin and modified silicone resin.

13. An electronic device, characterized in that: include: A circuit board and a packaging structure according to any one of claims 1 to 12, wherein the substrate is mounted on the circuit board and electrically connected to the circuit board.

14. A chip packaging method, characterized in that: At least the following steps are included: mounting at least one chip on a surface of the substrate; A heat-conducting cover plate is mounted on a side of the at least one chip facing away from the substrate, wherein the surface of the heat-conducting cover plate facing the substrate has at least one filling area, each of the filling areas corresponds to one or more chips, each of the filling areas has a receiving groove opening toward the substrate, a thermal interface material layer is filled between each chip and the bottom surface of the corresponding receiving groove, and a portion of the chip is received in the receiving groove; a first gap communicating with the receiving groove is defined between at least a portion of the opening edge of each receiving groove and the substrate; Filling material is injected into the receiving grooves through the first gap corresponding to each receiving groove and solidified, wherein, in each receiving groove, the filling material at least wraps the side surface of the thermal interface material layer.

15. The method according to claim 14, characterized in that Before the heat-conducting cover plate is mounted on the side of the at least one chip facing away from the substrate, the method further includes: An accommodating groove is formed at each of the filling regions of the heat-conducting cover plate.

16. The method according to claim 15, characterized in that The forming of a receiving groove at each of the filling areas of the heat-conducting cover plate specifically includes: A surrounding wall is formed along the edge of each filling area of the heat-conducting cover plate, and each surrounding wall and the corresponding filling area form an accommodating groove.

17. The method according to claim 15, characterized in that The forming of a receiving groove at each of the filling areas of the heat-conducting cover plate specifically includes: A groove recessed toward the interior of the heat-conducting cover plate is formed in each of the filling regions of the heat-conducting cover plate, and each of the grooves constitutes an accommodating slot.

18. The method according to claim 14, characterized in that The step of installing the heat-conducting cover plate on a side of the at least one chip facing away from the substrate specifically includes: Fixing at least one extension wall to the substrate, wherein each extension wall surrounds one or more chips, and a surrounding wall is provided along one end of each extension wall away from the substrate, and each extension wall has a hollow portion extending from the substrate to the corresponding surrounding wall to form the first gap; The heat-conducting cover plate is placed on a side of the at least one chip facing away from the substrate, and one end of each of the surrounding walls away from the corresponding extension wall is connected to the heat-conducting cover plate, wherein each of the surrounding walls extends along an edge of a corresponding filling area, and each of the surrounding walls and the corresponding filling area encloses a receiving groove.

19. The method according to any one of claims 14 to 18, characterized in that The step of installing the heat-conducting cover plate on a side of the at least one chip facing away from the substrate specifically includes: fixing a support portion to the substrate, wherein the support portion surrounds the at least one chip and a second gap is formed between a portion of the support portion and the substrate; The heat-conducting cover plate is placed on a side of the at least one chip facing away from the substrate, and one end of the support portion away from the substrate is connected to the heat-conducting cover plate, wherein the second gaps correspond to each of the first gaps.

20. The method according to claim 19, characterized in that Before fixing the support portion to the substrate, the method further comprises: A recess is formed in the support portion for cooperating with the substrate to form the second gap.

21. The method according to any one of claims 14 to 18, characterized in that The surface of the heat-conducting cover plate having the filling area is provided with a support portion, wherein the support portion surrounds the receiving groove corresponding to the at least one filling area, and an end of the support portion facing away from the heat-conducting cover plate has a recess; The step of installing the heat-conducting cover plate on a side of the at least one chip facing away from the substrate specifically includes: The heat-conducting cover plate is placed on a side of the at least one chip facing away from the substrate, and one end of the support portion away from the heat-conducting cover plate is connected to the substrate, wherein the recess cooperates with the substrate to form a second gap corresponding to each first gap.

22. The method according to claim 21, characterized in that Before placing the heat-conducting cover plate on a side of the at least one chip facing away from the substrate, the method further includes: The recess is formed at one end of the support portion facing away from the heat-conducting cover plate.

23. The method according to any one of claims 15 to 18, characterized in that Before the heat-conducting cover plate is mounted on the side of the at least one chip facing away from the substrate, the method further includes: The thermal interface material layer is formed on a surface of each chip facing away from the substrate.

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