Packaging structure, packaging method, heat dissipation cover processing method and computer equipment

Abstract

The embodiment of the invention provides a packaging structure, a packaging method, a heat dissipation cover processing method and computer equipment. The packaging structure comprises a packaging substrate; the chip is connected with the packaging substrate; the heat dissipation cover is connected with the packaging substrate and the chip, and the heat dissipation cover and the chip are connected through a metal heat conduction layer formed by welding metal materials; a welding interface, matched with a metal material, of the heat dissipation cover is designed to be of an embedded first cavity structure; the first cavity structure is used for containing the metal material in the process of forming the metal heat conduction layer through welding and containing the metal heat conduction layer formed through welding, and the side edge of the first cavity structure is designed to be in the range of preventing metal from being sputtered out of the first cavity structure in the process of forming the metal heat conduction layer through welding. According to the packaging structure provided by the embodiment of the invention, metal sputtering generated after the metal material is melted at a high temperature can be prevented, and the chip 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 cover processing method, and a computer device. Background Art

[0002] In the chip packaging process, in order to meet the heat dissipation requirements of the chip, the chip and the heat dissipation cover can be welded together through metal materials so that the heat dissipation cover can be used to conduct heat to the chip. However, during the welding process, high temperatures can cause the metal material to melt, resulting in metal sputtering, which affects the chip packaging effect. Summary of the invention

[0003] In view of this, an embodiment of the present application provides a packaging structure that can prevent metal sputtering caused by high-temperature melting of metal materials, thereby improving chip packaging effects.

[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;

[0008] A heat dissipation cover connecting the package substrate and the chip, wherein the heat dissipation cover and the chip are connected by a metal heat-conducting layer formed by welding a metal material;

[0009] The welding interface of the heat dissipation cover and the metal material is designed as an embedded first cavity structure; the first cavity structure is used to accommodate the metal material and the metal thermal conductive layer formed by welding during the process of welding to form the metal thermal conductive layer, and the side of the first cavity structure is designed to prevent metal from sputtering out of the range of the first cavity structure during the process of welding to form the metal thermal conductive layer.

[0010] Optionally, the first cavity structure includes: a side edge and a top surface embedded in the welding interface of the heat dissipation cover;

[0011] The side edge of the first cavity structure is used to control the flow of metal material within the first cavity structure during the process of welding to form the metal heat conductive layer, so as to prevent the metal from sputtering out of the range of the first cavity structure;

[0012] The top surface of the first cavity structure is used to support the structural shape of the first cavity structure.

[0013] Optionally, a height of a side of the first cavity structure is higher than a height of the metal material.

[0014] Optionally, the front surface of the chip is connected to the top surface of the packaging substrate via a bump structure; the packaging structure further includes: bottom filling glue;

[0015] The bottom filling glue is used to fill the gap between the front surface of the chip and the top surface of the packaging substrate, and to cover a first part of the area on the side of the chip, and a second part of the area on the side of the chip is not covered by the bottom filling glue;

[0016] The height of the side of the first cavity structure is lower than the sum of the heights of the metal material and the second portion of the side of the chip.

[0017] Optionally, the welding interface is located on a surface of the heat dissipation cover facing the chip, and an area of ​​the surface other than the welding interface is a plane area;

[0018] The height of the side of the first cavity structure is set to: the height difference between the back side of the chip and the plane area plus the height of the metal material.

[0019] Optionally, the planar area and the area surrounded by the support columns of the heat dissipation cover form a second cavity structure, and the second cavity structure is at least used to accommodate the chip and capacitors around the chip; the support columns of the heat dissipation cover are connected to the packaging substrate.

[0020] Optionally, the height of the second cavity structure is set to: the sum of the packaging height of the chip and the height of the metal material minus the height of the side of the first cavity structure;

[0021] The chip packaging height is the height between the back surface of the chip and the top surface of the packaging substrate.

[0022] Optionally, the side edges of the first cavity structure are vertical side edges, and the top surface is a plane or a curved surface.

[0023] Optionally, the side of the first cavity structure is an inclined side, and the top edge of the inclined side is inclined toward the interior of the first cavity structure; the inclination angle of the side of the first cavity structure is positively correlated with the thickness of the metal material, wherein the inclination angle is the angle between the inclined side and the horizontal plane.

[0024] Optionally, the side of the first cavity structure is an arc-shaped side, and the bottom edge of the arc-shaped side protrudes toward the inside of the first cavity structure.

[0025] Optionally, the first cavity structure is a cavity roughening structure, and the side edges of the first cavity structure are rough side edges, and / or the top surface is a rough top surface.

[0026] Optionally, a plurality of roughening units are provided on the side and / or top surface of the first cavity structure, and the roughening units are distributed uniformly on the side and / or top surface of the first cavity, or gradually distributed according to the flow or sputtering direction of the metal material.

[0027] Optionally, also include:

[0028] Solder fixing the capacitor on the surface of the packaging substrate;

[0029] Black glue used to fix the support column of the heat dissipation cover to the packaging substrate;

[0030] and solder balls located on the bottom surface of the packaging substrate.

[0031] In a second aspect, an embodiment of the present application provides a heat dissipation cover processing method, comprising: obtaining chip packaging design data, wherein the chip packaging design data at least includes chip parameters and metal material parameters;

[0032] Determine processing parameters of the heat dissipation cover according to the chip package design data, the processing parameters are used to process the welding interface of the heat dissipation cover and the metal material into an embedded first cavity structure, wherein the processing parameters at least include: design parameters of the first cavity structure; the design parameters are used to design the first cavity structure to accommodate the metal material and the metal heat conductive layer formed by welding during the process of forming the metal heat conductive layer by welding, and the side of the first cavity structure is designed to prevent the metal from sputtering out of the range of the first cavity structure during the process of forming the metal heat conductive layer by welding;

[0033] The heat dissipation cover is obtained by processing based on the processing parameters of the heat dissipation cover.

[0034] In a third aspect, an embodiment of the present application provides a packaging method, including:

[0035] Providing a packaging substrate, and connecting the chip to the packaging substrate;

[0036] attaching a metal material to the back side of the chip;

[0037] Providing a heat dissipation cover, wherein the heat dissipation cover cooperates with the welding interface of the metal material to be designed as an embedded first cavity structure;

[0038] Disposing the heat dissipation cover on the packaging substrate so that the metal material is accommodated in the first cavity structure of the heat dissipation cover;

[0039] A metal heat-conducting layer is formed between the back side of the chip and the heat dissipation cover by welding metal materials, and the metal heat-conducting layer is accommodated in the first cavity structure; wherein, during the process of welding to form the metal heat-conducting layer, the side of the first cavity structure blocks metal from sputtering out of the range of the first cavity structure.

[0040] In a fourth aspect, an embodiment of the present application provides a computer device, wherein the computer device includes the packaging structure described above.

[0041] The packaging structure provided in the embodiment of the present application includes: a packaging substrate; a chip connected to the packaging substrate; a heat dissipation cover connecting the packaging substrate and the chip, wherein the heat dissipation cover and the chip are connected to a metal thermal conductive layer formed by welding a metal material; the heat dissipation cover is designed to be an embedded first cavity structure in conjunction with the welding interface of the metal material; the first cavity structure is used to accommodate the metal material during the process of welding to form the metal thermal conductive layer, and to accommodate the metal thermal conductive layer formed by welding, and the side of the first cavity structure is designed to prevent metal from sputtering out of the range of the first cavity structure during the process of welding to form the metal thermal conductive layer.

[0042] It can be seen that in the packaging structure provided by the embodiment of the present application, the welding interface of the heat dissipation cover and the metal material is designed as an embedded first cavity structure, so that the first cavity structure of the heat dissipation cover can accommodate the metal material in the process of welding to form the metal heat conductive layer, and after welding to form the metal heat conductive layer, accommodate the metal heat conductive layer; because the side of the first cavity structure is designed to prevent the metal from sputtering out of the range of the first cavity structure in the process of welding to form the metal heat conductive layer, the metal flow and sputtering of the metal material can be controlled inside the first cavity structure in the process of welding to form the metal heat conductive layer, so as to avoid the metal from sputtering to the capacitors and other devices around the chip, and prevent the capacitors and other devices around the chip from short-circuiting. Since the first cavity structure is the welding interface of the heat dissipation cover and the metal material, and the metal flow and sputtering of the metal material are controlled inside the first cavity structure, the welding effect of the metal heat conductive layer formed by welding can be improved, that is, the void rate of the metal heat conductive layer is reduced, the contact area between the chip and the heat dissipation cover is increased, and the heat dissipation effect is improved. Therefore, in the process of welding to form a metal thermal conductive layer, the embodiment of the present application can prevent metal from sputtering out of the range of the first cavity structure, thereby protecting capacitors and other devices around the chip and improving the heat dissipation effect, thereby improving the packaging effect of the chip package. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] 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.

[0044] Figure 1 This is an example diagram of a packaging structure;

[0045] Figure 2 This is an example diagram of another packaging structure;

[0046] Figure 3 is based on Figure 2 A structural example diagram of a heat dissipation cover;

[0047] Figure 4 This is a partial enlarged view of the packaging structure before the metal heat-conducting layer is formed;

[0048] Figure 5 This is another example diagram of the structure of the heat dissipation cover;

[0049] Figure 6 is another optional structural example diagram of another heat dissipation cover;

[0050] Figure 7 This is another structural example diagram of a heat dissipation cover;

[0051] Figure 8 is a structural example diagram of another heat dissipation cover;

[0052] Fig. 9 is a structural example diagram of a heat sink provided in an embodiment of the present application;

[0053] Fig.10 This is another example diagram of a packaging structure;

[0054] Fig.11 is a flow chart of a heat dissipation cover processing method provided in an embodiment of the present application;

[0055] Fig.12 It is a flow chart of a packaging method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] 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.

[0057] In the chip packaging process, in order to better meet the heat dissipation requirements of the chip, the chip and the heat dissipation cover can be welded by metal materials, so as to form a metal heat conductive layer between the chip and the heat dissipation cover to conduct the heat of the chip to the heat dissipation cover. Specifically, taking the flip-chip packaging method as an example, during the welding process, the metal material arranged on the back of the chip can be welded with the heat dissipation cover by a high-temperature reflow process to form a metal heat conductive layer between the chip and the heat dissipation cover. However, during the above process, the high temperature generated by welding may cause the metal material to melt and produce sputtering. The sputtered metal may fall on the capacitors around the chip, thereby causing a short circuit of the capacitor.

[0058] A packaging structure capable of protecting the capacitor may be to mount a cover plate (such as a metal cover plate) on top of the capacitor, thereby preventing metal material from sputtering onto the capacitor during high-temperature welding of the metal material, thereby protecting the capacitor. Figure 1 This is an example diagram of a packaging structure. Figure 1 The packaging structure includes a substrate 101, a chip 102, a capacitor 103, a metal cover 104, a heat dissipation cover 105, and a metal heat conductive layer 106. Specifically, during the welding process, the chip 102, the metal material and the heat dissipation cover 105 need to be welded together through a welding process to form a metal heat conductive layer 106 between the chip 102 and the heat dissipation cover 105. During this process, the metal cover 104 above the capacitor 103 can prevent the metal material from being melted at high temperature and sputtering onto the capacitor, thereby protecting the capacitor.

[0059] Although the above-mentioned packaging structure can protect the capacitor, with the iteration of chip products, the size and position of the chip and capacitor will change, and the size of the metal cover needs to be redesigned. If the design of the metal cover is unreasonable, it may affect the heat dissipation performance of the chip. At the same time, the setting of the metal cover needs to occupy a certain space. As the distance between the chip and the capacitor becomes smaller and smaller, the metal cover may be unable to be mounted.

[0060] In addition, the sputtering of metal materials will also increase the void ratio of the metal thermal conductive layer formed by welding, thereby reducing the contact area between the chip and the heat dissipation cover, thereby reducing the heat dissipation effect. The design of the above-mentioned packaging structure can only prevent the melting of metal materials from sputtering onto the capacitor, but cannot prevent the sputtering of metal materials. Therefore, it cannot solve the problem of reduced heat dissipation effect caused by the increase in void ratio.

[0061] Another packaging structure for protecting capacitor chips can be: a circle of silicone strips is set around the metal material to block metal sputtering. Although this packaging structure can block metal sputtering, it requires an additional mounting structure (such as an adapter plate) to mount the silicone strip around the metal material; this process is complicated and costly.

[0062] In view of this, it is necessary to provide a packaging structure that can block the sputtering of metal materials after high-temperature melting, protect the capacitor and reduce the void ratio of the metal thermal conductive layer, thereby improving the heat dissipation effect on the basis of protecting the circuit, thereby achieving the purpose of improving the chip packaging effect.

[0063] Taking the chip flip packaging method as an example, Figure 2 This is an example diagram of another packaging structure. Figure 3 is based on Figure 2 The structure of the heat sink cover is shown in Figure 1. Figure 2 and Figure 3 , the packaging structure provided in the embodiment of the present application includes:

[0064] The packaging substrate 200 can be used as a carrier for semiconductor chip packaging, and can provide electrical connection, support, protection, heat dissipation, etc. for the chip;

[0065] A chip 201 connected to the packaging substrate;

[0066] A metal heat-conducting layer 202 connecting the chip 201 and the heat-dissipating cover 203, wherein the metal heat-conducting layer 202 is formed by welding a metal material;

[0067] The heat dissipation cover 203 and the chip 201 are connected by a metal heat conductive layer 202 formed by welding a metal material; for example, the heat dissipation cover has a welding interface with a matching metal material, and the welding interface of the heat dissipation cover can be welded to the metal material on the back of the chip 201 to form a metal heat conductive layer 202 to connect with the back of the chip 201, wherein, with reference to Figure 2 , the back surface of the chip is the top surface of the chip 201, and the front surface of the chip is the bottom surface of the chip 201;

[0068] The metal material may be a metal material with a low melting point, such as a metal material with a melting point of about 150 degrees (such as indium). The chip, the metal material and the heat dissipation cover are welded together through a reflow process to form a metal thermal conductive layer 202 .

[0069] During the above process, the maximum temperature can reach about 240 degrees, which may cause the metal material to melt and produce sputtering; based on this, the heat dissipation cover 203 provided in the embodiment of the present application is designed to cooperate with the welding interface of the metal material as an embedded first cavity structure 204, and the first cavity structure 204 is used to accommodate the metal material during the process of welding to form the metal thermal conductive layer 202, and, after welding to form the metal thermal conductive layer 202, to accommodate the metal thermal conductive layer 202.

[0070] In the process of welding to form a metal thermal conductive layer, the embodiment of the present application can control the sputtering of the melted metal in the metal material within the range of the first cavity structure, thereby avoiding the sputtering of the metal material onto the capacitors around the chip during high-temperature welding of the metal material, and reducing the void ratio of the metal thermal conductive layer formed by welding.

[0071] Specifically, the side of the first cavity structure 204 can be designed to prevent the metal melted by the metal material from sputtering out of the range of the first cavity structure during the process of welding to form the metal heat conductive layer. For example, the side of the first cavity structure 204 can control the flow direction and sputtering direction of the metal material, so that the metal material flows and sputters inside the first cavity structure.

[0072] It can be seen that in the packaging structure provided by the embodiment of the present application, the welding interface of the heat dissipation cover and the metal material is designed as an embedded first cavity structure, so that the first cavity structure of the heat dissipation cover can accommodate the metal material in the process of welding to form the metal heat conductive layer, and after welding to form the metal heat conductive layer, accommodate the metal heat conductive layer; because the side of the first cavity structure is designed to prevent the metal from sputtering out of the range of the first cavity structure in the process of welding to form the metal heat conductive layer, the metal flow and sputtering of the metal material can be controlled inside the first cavity structure in the process of welding to form the metal heat conductive layer, so as to avoid the metal from sputtering to the capacitors and other devices around the chip, and prevent the capacitors and other devices around the chip from short-circuiting. Since the first cavity structure is the welding interface of the heat dissipation cover and the metal material, and the metal flow and sputtering of the metal material are controlled inside the first cavity structure, the welding effect of the metal heat conductive layer formed by welding can be improved, that is, the void rate of the metal heat conductive layer is reduced, the contact area between the chip and the heat dissipation cover is increased, and the heat dissipation effect is improved. Therefore, in the process of welding to form a metal thermal conductive layer, the embodiment of the present application can prevent metal from sputtering out of the range of the first cavity structure, thereby protecting capacitors and other devices around the chip and improving the heat dissipation effect, thereby improving the packaging effect of the chip package.

[0073] In an optional implementation, the embodiment of the present application can design the height of the side of the first cavity structure so that the side of the first cavity structure can prevent the metal material from sputtering out of the range of the first cavity structure during the process of welding to form the metal heat-conducting layer. Specifically, since the height of the metal material will decrease after the metal heat-conducting layer is formed through the welding process, that is, the height of the metal material is higher than the height of the metal heat-conducting layer, in order to ensure that the metal sputtering generated by the melting of the metal material can be blocked within the range of the first cavity structure, the metal material used to form the metal heat-conducting layer should be completely embedded in the interior of the first cavity structure. Therefore, in an optional implementation, the embodiment of the present application can set the height of the side of the first cavity structure to take into account the height of the metal material.

[0074] In an optional implementation, the height of the side of the first cavity structure 204 may be higher than the height of the metal material.

[0075] In an alternative embodiment, Figure 4 This is a partial enlarged view of the packaging structure before the metal thermal conductive layer is formed. Figure 2 and Figure 4 The metal heat conducting layer 202 is formed by welding the metal material 202A. The height of the side of the first cavity structure is h, and the height of the metal material is a. The height h of the side of the first cavity structure 204 is greater than the height a of the metal material 202A, that is, h>a.

[0076] Furthermore, the packaging structure also includes a bump structure 205 located between the front surface of the chip 201 and the top surface of the packaging substrate 200, and the chip 201 is connected to the packaging substrate 200 through the bump structure 205; in the embodiment of the present application, the bump structure may at least include a solder bump or a copper pillar bump. In the actual packaging process, the corresponding bump structure may be selected to achieve connection with the packaging substrate according to the application and performance requirements of various chips.

[0077] Furthermore, the packaging structure also includes a bottom filling glue 206; the bottom filling glue 206 is used to fill the gap between the front surface of the chip 201 and the top surface of the packaging substrate, and to cover a partial area of ​​the chip side of the chip 201 (for ease of explanation, the partial area of ​​the chip side covered by the bottom filling glue is referred to as the first partial area); in an embodiment of the present application, the material of the bottom filling glue 206 can be epoxy resin.

[0078] After the front side of the chip 201 is connected to the top side of the package substrate 200 through the bump structure 205, the gap between the chip and the package substrate can be filled with bottom filling glue, and the first part of the chip side of the chip 201 can be covered, so as to protect the bump structure and the chip from physical impact and wear, and reduce damage caused by mechanical stress such as vibration. Among them, epoxy resin has good bonding performance and mechanical strength, can provide good mechanical connection, improve the stability and durability of the package structure, and can be used as the material of the bottom filling glue.

[0079] Since the bottom filling glue has good adhesion and mechanical strength, and covers the first part of the chip side area of ​​the chip 201, when setting the height of the first cavity structure, it should also be ensured that the heat dissipation cover 203 and the bottom filling glue 206 covering the part of the chip side area cannot contact each other, thereby reducing the interference of the bottom filling glue causing uneven mounting of the heat dissipation cover.

[0080] In an optional implementation, the partial area of ​​the chip side that is not covered by the bottom filling glue can be called the second partial area, so that the height of the side of the first cavity structure 204 is lower than the sum of the heights of the metal material 202A and the second partial area of ​​the chip side; that is, the sum of the heights obtained by adding the heights of the metal material 202A and the partial area of ​​the chip side that is not covered by the bottom filling glue 206 (the second partial area) is higher than the height of the side of the first cavity structure 204.

[0081] In an alternative embodiment, referring to Figure 4 , the height of the side of the first cavity structure is h, the height of the metal material is a, and the height of the second part of the chip side area not covered by the bottom filling glue is b. Then, the height h of the side of the first cavity structure 204 is lower than the sum of the heights of the metal material 202A and the second part of the chip side area not covered by the bottom filling glue 206, that is, h<(a+b).

[0082] In a further optional implementation, the welding interface of the heat dissipation cover is located on the surface of the heat dissipation cover facing the chip, and the area of ​​the surface except the welding interface is a plane area 207; thus, the height of the side of the first cavity structure 204 can be set to: the height difference between the back side of the chip 201 and the plane area 207 of the heat dissipation cover 203, plus the height of the metal material 202A.

[0083] Continue to refer to Figure 4 , the height difference between the back side of the chip 201 and the plane area of ​​the heat dissipation cover 203 can be c, then the height h of the side of the first cavity structure 204 can be set to: the height difference c between the back side of the chip 201 and the plane area of ​​the heat dissipation cover 203, plus the height a of the metal material 202A, that is, h = (a+c).

[0084] Further, continue to refer to Figure 2 and Figure 3 The heat dissipation cover 203 further includes: a support column 208 of the heat dissipation cover 203; an area surrounded by the support column 208 and the plane area 207 forms a second cavity structure 209, and the second cavity structure 209 is used to accommodate the chip 201 and the capacitor 210 around the chip.

[0085] In an optional implementation, the height of the second cavity structure 209 is set to: the sum of the packaging height of the chip and the height of the metal material minus the height of the side of the first cavity structure 204;

[0086] The chip packaging height is the height between the back surface of the chip 201 and the top surface of the packaging substrate 200 .

[0087] In the embodiments of the present application, Figure 2 and Figure 3 The packaging structure also includes: solder 211 for fixing the capacitor 210 on the surface of the packaging substrate; black glue 212 for fixing the support column 208 of the heat dissipation cover to the packaging substrate; and solder balls 213 located on the bottom surface of the packaging substrate.

[0088] Solder is a welding material. Using solder as a welding material for capacitors and package substrates can form a stable connection while ensuring the circuit connection between the capacitor and the package substrate.

[0089] Black glue has good sealing performance. Using black glue as the connecting material between the heat sink cover and the packaging substrate can protect the chip contained in the heat sink cover and the components around the chip from being impacted or damaged.

[0090] The solder balls on the bottom surface of the packaging substrate can provide mechanical support for the packaging substrate while providing an electrical connection path between the packaging substrate and the external circuit.

[0091] It can be seen that in the packaging structure provided by the embodiment of the present application, the welding interface of the heat dissipation cover and the metal material is designed as an embedded first cavity structure, so that the first cavity structure of the heat dissipation cover can accommodate the metal material in the process of welding to form the metal heat conductive layer, and after welding to form the metal heat conductive layer, accommodate the metal heat conductive layer; because the side of the first cavity structure is designed to prevent the metal material from welding the molten metal and sputtering out of the range of the first cavity structure in the process of welding to form the metal heat conductive layer, the metal flow and sputtering of the metal material can be controlled inside the first cavity structure in the process of welding to form the metal heat conductive layer, so as to avoid the metal from sputtering to the capacitors and other devices around the chip, and prevent the capacitors and other devices around the chip from short-circuiting. Since the first cavity structure is the welding interface of the heat dissipation cover and the metal material, the metal flow and sputtering of the metal material are controlled inside the first cavity structure, which can improve the welding effect of the metal heat conductive layer formed by welding, that is, reduce the void rate of the metal heat conductive layer, increase the contact area between the chip and the heat dissipation cover, and thus improve the heat dissipation effect. Therefore, in the process of welding to form a metal thermal conductive layer, the embodiment of the present application can prevent the molten metal from being welded by the metal material and sputtering out of the range of the first cavity structure, thereby protecting the capacitors and other devices around the chip, improving the heat dissipation effect, and improving the packaging effect of the chip package.

[0092] When the side of the first cavity structure is designed to prevent the metal material from sputtering out of the first cavity structure (for example, the height of the side of the first cavity structure is higher than the height of the metal material), the embodiments of the present application support a variety of shapes of the first cavity structure and a variety of morphological settings of the side of the first cavity structure.

[0093] Specifically, the first cavity structure may include: a side and a top surface embedded in the welding interface of the heat dissipation cover; wherein the top surface of the first cavity structure is used to support the structural shape of the first cavity structure; the function and height setting of the side of the first cavity structure can refer to the description of the corresponding part of the previous text, which will not be repeated here, and the following will be further explained mainly from the perspective of the side shape setting.

[0094] In an optional implementation, the embodiment of the present application supports the side of the first cavity structure to be a vertical side. For example, the first cavity structure can be a rectangular cavity structure, that is, the shape of the first cavity structure is a rectangle; thus, the side of the first cavity structure can be a vertical side, and accordingly, the top surface of the structural shape supporting the first cavity structure can be a plane.

[0095] In an optional implementation, the embodiment of the present application may also support the first cavity structure to be an arc-shaped cavity structure. For example, the side edges of the first cavity structure may be vertical side edges, and the top surface may be an arc-shaped plane. Figure 5 This is another example of the structure of the heat dissipation cover, in which: Figure 5 and Figure 3 The same structure can refer to the description of the corresponding part above.

[0096] Reference Figure 5 The side edges of the first cavity structure 504 are vertical side edges, and the top surface is an arc-shaped plane.

[0097] In other possible implementations, the embodiments of the present application may also support the side of the first cavity structure to be a non-vertical side, such as a curved side, or an inclined side.

[0098] In an optional implementation, the side of the first cavity structure may be an arc-shaped side. Figure 6 is another optional structural example diagram of another heat dissipation cover, wherein: Figure 6 and Figure 3 The same structure can refer to the description of the corresponding part above.

[0099] Reference Figure 6 The side of the first cavity structure 604 is an arc-shaped side, and the bottom edge of the arc-shaped side is convex toward the inside of the first cavity structure. Designing the first cavity structure as an arc-shaped cavity structure is beneficial to the stress distribution at the welding point between the metal material and the chip during high-temperature welding, reducing the risk of damage or chip warping, and can better reduce the overflow of metal material, which is beneficial to preventing metal sputtering caused by the melting of metal material welding, and further improving the packaging effect.

[0100] In an optional implementation, the side of the first cavity structure can be an inclined side, and the top edge of the inclined side is inclined toward the interior of the first cavity structure; the inclination angle of the side of the first cavity structure is positively correlated with the thickness of the metal material, wherein the inclination angle is the angle between the inclined side and the horizontal plane. Figure 7 is another structural example diagram of a heat dissipation cover, wherein: Figure 7 and Figure 3 The same structure can refer to the description of the corresponding part above.

[0101] Reference Figure 7 , the side of the first cavity structure 704 is an inclined side, and the top edge of the inclined side is inclined toward the inside of the first cavity structure; the inclination angle of the side of the first cavity structure is positively correlated with the thickness of the metal material. Designing the side of the first cavity structure to be inclined toward the inside of the first cavity structure can reduce stress concentration at the welding point between the metal material and the chip during high-temperature welding, while reducing the risk of chip warping, and further improving the packaging effect.

[0102] As an optional implementation, the first cavity structure in the packaging structure provided in the embodiment of the present application may also be a cavity roughening structure, and the side edges of the first cavity structure are rough side edges, and / or the top surface is a rough top surface. Figure 8 is another structural example diagram of a heat dissipation cover, wherein: Figure 8 and Figure 3 The same structure can refer to the description of the corresponding part above.

[0103] Cavity roughening refers to the process of increasing the surface roughness (side and / or top surface) of the first cavity structure of the heat dissipation cover through specific process steps. In this embodiment, a plurality of roughening units may be arranged on the side and / or top surface of the first cavity structure 804 to increase the roughness; the roughening units are, for example, protrusions and / or grooves. In the actual processing process, a large number of fine protrusions or grooves may be created on the surface of the first cavity structure through a specific process, thereby increasing the roughness of the surface of the first cavity structure.

[0104] Further, in an optional implementation, the distribution of the coarsening units may be: uniformly distributed on the side and / or top surface of the first cavity, or gradually distributed according to the flow or sputtering direction of the metal material.

[0105] Among them, the gradual distribution according to the flow or sputtering direction of the metal material refers to setting more coarsening units in the side or top area close to the flow direction / sputtering direction of the metal material. In other words, the coarsening units distributed in the side or top area close to the flow direction / sputtering direction of the metal material are denser and have higher roughness, which can help control the flow direction and flow rate of the metal material during welding and melting, reduce metal sputtering, and thus protect the capacitors and other devices around the chip. At the same time, roughening the first cavity structure can increase the contact surface area between the chip and the heat dissipation cover, so that the metal material can be more evenly distributed, reduce contact thermal resistance, improve heat conduction efficiency, and improve heat dissipation performance, thereby improving the packaging effect.

[0106] Furthermore, as an optional implementation, the heat dissipation structure provided in the embodiment of the present application may also be a heat sink. Fig. 9 is a structural example diagram of the heat sink provided in the embodiment of the present application, Fig.10 This is another example diagram of a packaging structure, in which: Fig.10 The heat dissipation structure used in the package structure shown is Fig. 9 The heat sink shown, Fig.10 and Figure 2 The same structure can refer to the description of the corresponding part above.

[0107] Reference Figures 9 and 10 The heat dissipation structure includes a heat sink 903, and accordingly, the heat sink 903 is designed to be an embedded first cavity structure 904 in conjunction with the welding interface of the metal material; the first cavity structure 904 is used to accommodate the metal material in the process of welding to form a metal thermal conductive layer, and to accommodate the metal thermal conductive layer formed by welding, and the side of the first cavity structure 904 is designed to prevent metal from sputtering out of the range of the first cavity structure in the process of welding to form a metal thermal conductive layer.

[0108] The embodiment of the present application also provides a heat dissipation cover processing method, which can be applied to a computer numerical control (CNC) system, and the heat dissipation cover in the packaging structure described above is obtained by controlling the processing by the CNC system. Fig.11 is a flow chart of a heat dissipation cover processing method provided in an embodiment of the present application, referring to Fig.11 The heat dissipation cover processing method includes the following steps.

[0109] Step S1101: Acquire chip packaging design data, where the chip packaging design data at least includes chip parameters and metal material parameters.

[0110] The heat dissipation cover processing method provided in the embodiment of the present application can obtain chip packaging design data, which may include chip parameters and metal material parameters, and then the heat dissipation cover can be processed according to the obtained chip packaging design data.

[0111] In the embodiment of the present application, the chip parameter may at least include the height of the chip, and the metal material parameter may at least include the height of the metal material.

[0112] Step S1102: Determine processing parameters of the heat dissipation cover according to the chip package design data, wherein the processing parameters are used to process the welding interface of the heat dissipation cover and the metal material into an embedded first cavity structure, wherein the processing parameters at least include: design parameters of the first cavity structure; the design parameters are used to design the first cavity structure to accommodate the metal material during the process of welding to form the metal thermal conductive layer, and to accommodate the metal thermal conductive layer formed by welding, and the side of the first cavity structure is designed to prevent the metal from sputtering out of the range of the first cavity structure during the process of welding to form the metal thermal conductive layer.

[0113] In the embodiment of the present application, the processing parameters of the heat dissipation cover can be determined according to the obtained chip package design data, and according to the processing parameters, the welding interface of the heat dissipation cover and the metal material can be processed into an embedded first cavity structure. The processing parameters of the heat dissipation cover can at least include the design parameters of the first cavity structure of the heat dissipation cover, so that according to the design parameters, the first cavity structure can be designed to accommodate the metal material in the process of welding to form the metal thermal conductive layer, and to accommodate the metal thermal conductive layer formed by welding, wherein the side of the first cavity structure can be designed to prevent the metal from sputtering out of the range of the first cavity structure in the process of welding to form the metal thermal conductive layer; thereby, the metal can be prevented from sputtering to the capacitors and other devices around the chip, and the capacitors and other devices around the chip can be prevented from short-circuiting, thereby playing a protective role.

[0114] In an optional implementation, the design parameters of the first cavity structure may include side design parameters of the side of the first cavity structure, and top surface design parameters of the top surface; the side design parameters are used to design the side of the first cavity structure as follows: in the process of welding to form a metal thermal conductive layer, the flow of metal material is controlled within the first cavity structure to prevent metal from sputtering out of the range of the first cavity structure; the top surface design parameters are used to design the top surface of the first cavity structure to support the structural shape of the first cavity structure.

[0115] Furthermore, the side design parameters may include: the height of the side of the first cavity structure.

[0116] Among them, since the height of the metal material will decrease after the metal material is welded to form the metal heat-conducting layer, that is, the height of the metal material is higher than the height of the metal heat-conducting layer, in order to ensure that the metal sputtering generated by the melting of the metal material can be completely blocked, the metal material used to form the metal heat-conducting layer should be completely embedded in the first cavity structure. Therefore, the height of the metal material should be considered when setting the height of the side of the first cavity structure.

[0117] In an optional implementation, the height of the side of the first cavity structure may be higher than the height of the metal material.

[0118] Furthermore, in an embodiment of the present application, taking the chip flip-chip packaging method as an example, the gap between the front side of the chip and the top surface of the packaging substrate is filled with bottom filling glue, and the bottom filling glue covers a partial area of ​​the side of the chip (for ease of explanation, the partial area of ​​the side of the chip covered by the bottom filling glue is called the first partial area), wherein the back side of the chip is the top surface of the chip, and the front side of the chip is the bottom surface of the chip.

[0119] Since the bottom filling glue has good adhesion and mechanical strength and covers the first part of the side area of ​​the chip, when setting the height of the side of the first cavity structure, it should also be ensured that the heat dissipation cover and the bottom filling glue covering the part of the side area of ​​the chip cannot contact each other, thereby reducing the interference of the bottom filling glue causing uneven mounting of the heat dissipation cover.

[0120] In an optional implementation, the partial area of ​​the chip side that is not covered by the bottom filling glue can be called the second partial area, so that the height of the side of the first cavity structure is lower than the sum of the heights of the metal material and the second partial area of ​​the chip side; that is, the sum of the heights obtained by adding the heights of the metal material and the partial area of ​​the chip side that is not covered by the bottom filling glue (the second partial area) is higher than the height of the side of the first cavity structure 204.

[0121] Therefore, in an embodiment of the present application, the height of the side of the first cavity structure can be set to: the height difference between the back side of the chip and the plane area of ​​the heat dissipation cover, plus the height of the metal material; wherein the plane area of ​​the heat dissipation cover is the area on the surface of the heat dissipation cover facing the chip excluding the first cavity structure.

[0122] Furthermore, the processing parameters may also include: design parameters of a second cavity structure, where the second cavity structure is at least used to accommodate the chip and capacitors around the chip.

[0123] In the embodiment of the present application, the second cavity structure is formed by the support column of the heat dissipation cover and the area surrounded by the plane area.

[0124] In an optional implementation, the height of the second cavity structure may be set to: the sum of the packaging height of the chip and the height of the metal material minus the height of the side of the first cavity structure;

[0125] The chip packaging height is the height between the back surface of the chip and the top surface of the packaging substrate.

[0126] Furthermore, as an optional implementation, the processing parameters of the heat dissipation cover may also include the shape type of the first cavity structure, and the shape type of the first cavity structure may include at least a rectangular cavity structure, an arc-shaped cavity structure, and a cavity roughening structure. Specifically, the processing may be performed by setting the side type and the top surface type of the first cavity structure, wherein the side type includes at least a vertical side, an arc-shaped side, and an inclined side; and the top surface type includes at least a plane and an arc surface. In the actual processing process, the corresponding shape type of the first cavity structure may be selected for processing according to the product processing requirements, thereby obtaining a heat dissipation cover that meets the heat dissipation requirements.

[0127] Step S1103: processing the heat dissipation cover based on the processing parameters of the heat dissipation cover.

[0128] In an embodiment of the present application, based on the processing parameters of the heat sink cover determined above, the CNC system can control the corresponding packaging process devices to process the heat sink cover, thereby obtaining a heat sink cover that can block the high-temperature melting and sputtering of metal materials during the formation of the metal thermal conductive layer, thereby improving the chip packaging effect.

[0129] In other embodiments, the heat dissipation cover of the packaging structure provided in the embodiment of the present application can also be obtained by die stamping.

[0130] 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.

[0131] Fig.12 is a flow chart of a packaging method provided in an embodiment of the present application, referring to Fig.12 , the packaging method may include:

[0132] Step S1201: provide a packaging substrate, and connect the chip to the packaging substrate.

[0133] Before connecting the chip to the packaging substrate, the packaging substrate can be pre-processed, such as substrate pre-baking. Substrate pre-baking refers to the process of pre-drying the packaging substrate at a certain time and temperature before chip packaging. The baking process can effectively remove the residual moisture in the packaging substrate and reduce the bubbles formed by the evaporation of moisture in the subsequent welding process, thereby improving the firmness of the welding point and the reliability of the subsequent electrical connection, so as to facilitate the subsequent surface mounting technology (Surface Mount Technology, SMT) on the surface of the packaging substrate.

[0134] In an optional implementation, before the package substrate and the chip are bonded, the capacitor can be mounted on the substrate surface first, and then the chip can be mounted, because the size of the capacitor is smaller than that of the chip. As a small component, the capacitor can be mounted before the chip to avoid the shadow effect. If the chip is mounted first, its larger size will cause a shadow under the welding point, which may affect the welding quality of small components such as capacitors.

[0135] In the process of bonding the package substrate to the chip, a bump structure may be used, and a high-temperature reflow process may be performed to mount the chip to the surface of the package substrate.

[0136] Furthermore, the packaging method further comprises:

[0137] The gap between the front surface of the chip and the packaging substrate, and the first partial area of ​​the side of the chip (for ease of explanation, the partial area of ​​the side of the chip covered by the bottom filling glue is called the first partial area) are filled with bottom filling glue.

[0138] After the front side of the chip is connected to the top surface of the packaging substrate through the bump structure, the bottom filling glue can be filled in the gap between the chip and the packaging substrate, and cover part of the side area of ​​the chip (the first part area), so as to protect the bump structure and the chip from physical impact and wear, reduce damage caused by mechanical stress such as vibration, and complete the connection between the chip and the packaging substrate.

[0139] Step S1202: attaching metal material to the back side of the chip.

[0140] Before forming the metal heat-conducting layer, a metal material (such as indium) may be mounted on the back side of the chip, and the metal material will be used as the material for subsequently forming the metal heat-conducting layer.

[0141] Step S1203: providing a heat dissipation cover, wherein the heat dissipation cover is designed to have an embedded first cavity structure in conjunction with a welding interface of a metal material.

[0142] Since the metal material will melt and produce metal sputtering during the subsequent process, causing capacitor short circuit, a first cavity structure can be set on the heat dissipation cover used to bond the chip to block the metal sputtering caused by the melting of the metal material and to accommodate the formed metal thermal conductive layer, thereby achieving bonding between the heat dissipation cover and the chip.

[0143] Step S1204: disposing the heat dissipation cover on the packaging substrate so that the metal material is accommodated in the first cavity structure of the heat dissipation cover.

[0144] In order to ensure that the metal material is completely embedded in the first cavity structure, and at the same time ensure that the heat dissipation cover and the bottom filling glue covering the side of the chip cannot contact each other, and reduce the interference of the bottom filling glue on the heat dissipation performance of the heat dissipation cover, the height of the metal material and the height of the bottom filling glue should be considered when setting the height of the side of the first cavity structure.

[0145] In an optional implementation, the second portion of the chip side is not covered by the bottom filling glue, so that the height of the side of the first cavity structure is higher than the height of the metal material and lower than the sum of the heights of the metal material and the second portion of the chip side.

[0146] Furthermore, the heat dissipation cover may also include a second cavity structure at least for accommodating the chip and capacitors around the chip.

[0147] In an embodiment of the present application, the second cavity structure is formed by the support column of the heat dissipation cover and the area surrounded by the planar area; wherein the planar area of ​​the heat dissipation cover is the area on the surface of the heat dissipation cover facing the chip excluding the first cavity structure.

[0148] In an optional implementation, the height of the second cavity structure may be set to: the sum of the packaging height of the chip and the height of the metal material minus the height of the side of the first cavity structure;

[0149] The chip packaging height is the height between the back surface of the chip and the top surface of the packaging substrate.

[0150] Step S1205: forming a metal thermal conductive layer between the back side of the chip and the heat dissipation cover by welding metal materials, and the metal thermal conductive layer is accommodated in the first cavity structure; wherein, in the process of welding to form the metal thermal conductive layer, the side of the first cavity structure blocks the metal from sputtering out of the range of the first cavity structure.

[0151] After the heat dissipation cover and the chip are bonded together, a high-temperature reflow soldering process is required to form a metal thermal conductive layer through the metal material between the heat dissipation cover and the chip, so as to achieve the connection between the chip and the heat dissipation cover, thereby meeting the heat dissipation requirements of the chip; during the above process, since the metal material is completely contained in the first cavity structure, the side of the first cavity structure can block the molten metal from the welding of the metal material and sputter out of the range of the first cavity structure, thereby protecting the capacitors and other devices around the chip and improving the packaging effect.

[0152] Furthermore, after the above packaging process is completed, BGA (Ball Grid Array) ball planting is required to place solder balls (such as tin balls) on the bottom surface of the packaging substrate so that the core and the external chip can be electrically connected.

[0153] An embodiment of the present application further provides a computer device, such as a terminal device or a server device, wherein the computer device includes the packaging structure described in the aforementioned embodiment.

[0154] 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.

[0155] 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; A heat dissipation cover connecting the package substrate and the chip, wherein the heat dissipation cover and the chip are connected by a metal heat-conducting layer formed by welding a metal material; The welding interface of the heat dissipation cover and the metal material is designed as an embedded first cavity structure; the first cavity structure is used to accommodate the metal material and the metal thermal conductive layer formed by welding during the process of welding to form the metal thermal conductive layer, and the side of the first cavity structure is designed to prevent metal from sputtering out of the range of the first cavity structure during the process of welding to form the metal thermal conductive layer.

2. The packaging structure according to claim 1, characterized in that: The first cavity structure includes: a side edge and a top surface embedded in the welding interface of the heat dissipation cover; The side edge of the first cavity structure is used to control the flow of metal material within the first cavity structure during the process of welding to form the metal heat conductive layer, so as to prevent the metal from sputtering out of the range of the first cavity structure; The top surface of the first cavity structure is used to support the structural shape of the first cavity structure.

3. The packaging structure according to claim 2, characterized in that: The height of the side of the first cavity structure is higher than the height of the metal material.

4. The packaging structure according to claim 3, characterized in that: The front surface of the chip is connected to the top surface of the packaging substrate through a bump structure; the packaging structure also includes: bottom filling glue; The bottom filling glue is used to fill the gap between the front surface of the chip and the top surface of the packaging substrate, and to cover a first part of the area on the side of the chip, and a second part of the area on the side of the chip is not covered by the bottom filling glue; The height of the side of the first cavity structure is lower than the sum of the heights of the metal material and the second portion of the side of the chip.

5. The packaging structure according to claim 4, characterized in that: The welding interface is located on the surface of the heat dissipation cover facing the chip, and the area of ​​the surface except the welding interface is a plane area; The height of the side of the first cavity structure is set to: the height difference between the back side of the chip and the plane area plus the height of the metal material.

6. The packaging structure according to claim 4, characterized in that: The plane area and the area surrounded by the support column of the heat dissipation cover form a second cavity structure, and the second cavity structure is at least used to accommodate the chip and the capacitor around the chip; the support column of the heat dissipation cover is connected to the packaging substrate.

7. The packaging structure according to claim 6, characterized in that: The height of the second cavity structure is set to: the sum of the packaging height of the chip and the height of the metal material minus the height of the side of the first cavity structure; The chip packaging height is the height between the back surface of the chip and the top surface of the packaging substrate.

8. The packaging structure according to any one of claims 3 to 7, characterized in that: The side edges of the first cavity structure are vertical side edges, and the top surface is a plane or a curved surface.

9. The packaging structure according to any one of claims 3 to 7, characterized in that: The side of the first cavity structure is an inclined side, and the top edge of the inclined side is inclined toward the inside of the first cavity structure; the inclination angle of the side of the first cavity structure is positively correlated with the thickness of the metal material, wherein the inclination angle is the angle between the inclined side and the horizontal plane.

10. The packaging structure according to any one of claims 3 to 7, characterized in that: The side of the first cavity structure is an arc-shaped side, and the bottom edge of the arc-shaped side protrudes toward the inside of the first cavity structure.

11. The packaging structure according to any one of claims 1 to 7, characterized in that: The first cavity structure is a cavity roughening structure, and the side edges of the first cavity structure are rough side edges, and / or the top surface is a rough top surface.

12. The packaging structure according to claim 11, characterized in that: The side and / or top surface of the first cavity structure are provided with a plurality of roughening units, and the roughening units are distributed uniformly on the side and / or top surface of the first cavity, or distributed gradually according to the flow or sputtering direction of the metal material.

13. The packaging structure according to claim 1, characterized in that: Also includes: Solder fixing the capacitor on the surface of the packaging substrate; Black glue used to fix the support column of the heat dissipation cover to the packaging substrate; and solder balls located on the bottom surface of the packaging substrate.

14. A method for processing a heat dissipation cover, characterized in that: include: Acquire chip packaging design data, wherein the chip packaging design data at least includes chip parameters and metal material parameters; Determine processing parameters of the heat dissipation cover according to the chip package design data, the processing parameters are used to process the welding interface of the heat dissipation cover and the metal material into an embedded first cavity structure, wherein the processing parameters at least include: design parameters of the first cavity structure; the design parameters are used to design the first cavity structure to accommodate the metal material and the metal heat conductive layer formed by welding during the process of forming the metal heat conductive layer by welding, and the side of the first cavity structure is designed to prevent the metal from sputtering out of the range of the first cavity structure during the process of forming the metal heat conductive layer by welding; The heat dissipation cover is obtained by processing based on the processing parameters of the heat dissipation cover.

15. The heat dissipation cover processing method according to claim 14, characterized in that: The chip parameters include the height of the chip, the metal material parameters include the height of the metal material, and the design parameters of the first cavity structure include side design parameters of the side of the first cavity structure and top surface design parameters of the top surface; The side design parameters are used to design the side of the first cavity structure so that, during the process of welding to form the metal heat conductive layer, the flow of the metal material is controlled within the first cavity structure to prevent the metal from sputtering out of the range of the first cavity structure; The top surface design parameters are used to design the top surface of the first cavity structure to support the structural shape of the first cavity structure.

16. The heat dissipation cover processing method according to claim 15, characterized in that: The side design parameters include the height of the side of the first cavity structure; the height of the side of the first cavity structure is higher than the height of the metal material, and lower than the sum of the heights of the metal material and the second part of the chip side area, and the second part of the chip side area is not covered by the bottom filling glue.

17. A packaging method, characterized in that: include: Providing a packaging substrate, and connecting the chip to the packaging substrate; attaching a metal material to the back side of the chip; Providing a heat dissipation cover, wherein the heat dissipation cover cooperates with the welding interface of the metal material to be designed as an embedded first cavity structure; Disposing the heat dissipation cover on the packaging substrate so that the metal material is accommodated in the first cavity structure of the heat dissipation cover; A metal heat-conducting layer is formed between the back side of the chip and the heat dissipation cover by welding metal materials, and the metal heat-conducting layer is accommodated in the first cavity structure; wherein, during the process of welding to form the metal heat-conducting layer, the side of the first cavity structure blocks metal from sputtering out of the range of the first cavity structure.

18. The packaging method according to claim 17, characterized in that: Also includes: Filling the gap between the front surface of the chip and the top surface of the packaging substrate, and the first part of the side of the chip with bottom filling glue; The second part of the chip side is not covered by the bottom filling glue, and the height of the side of the first cavity structure is higher than the height of the metal material and lower than the sum of the heights of the metal material and the second part of the chip side.

19. A computer device, characterized in that: Comprising a packaging structure as described in any one of claims 1-13.

Images