Base preparation process, base and electronic device packaging tube shell

Abstract

The invention provides a base preparation process, a base and an electronic device packaging tube shell. The base preparation process comprises the following steps: forming a substrate of a diamond / copper composite material; carrying out primary metallization on the surface of the substrate to form a first metal layer; grinding and polishing the surface of the first metal layer; performing secondary metallization on the surface of the first metal layer to form a second metal layer; and grinding and polishing the surface of the second metal layer. According to the base preparation process, the base and the electronic device packaging tube shell, the base adopts the substrate made of the diamond / copper composite material, and the high heat conductivity, low expansion coefficient and low density of the diamond / copper composite material can solve the problems of heat dissipation, flatness and weight; the first metal layer and the second metal layer can improve the surface appearance of the diamond / copper composite material substrate, and the reliability of electronic device packaging can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of packaging technology, and in particular to a base preparation process, a base and an electronic device packaging tube shell. Background Art

[0002] As the market for high-power GaN discrete devices in the field of RF communications gradually increases, the power and size of the devices are also increasing. At present, the common high-power GaN devices on the market are sampled in ceramic packaging. However, as the power and size of the device increase, it also brings the following problems to the device packaging:

[0003] (1) The CuW or CuMo composite materials commonly used in ceramic packaging have a thermal conductivity between 175 and 300 W / (m·K). The poor thermal conductivity leads to poor heat dissipation of the device, which makes it difficult to meet the heat dissipation requirements of current high-power devices and easily leads to chip reliability problems.

[0004] (2) Conventional base materials have a large thermal expansion coefficient. To accommodate large-sized devices, the size of the tube shell becomes larger, which can easily lead to poor flatness under stress, affecting the bonding of the patch and easily causing patch mismatch, leading to product failure during use;

[0005] (3) In response to the aerospace industry’s demand for reducing the weight of chips, the weight of conventional base materials will increase as the size increases, causing inconvenience in use.

[0006] In other words, existing ceramic packages are restricted in their use due to issues with heat dissipation, flatness, and weight. Summary of the invention

[0007] The main purpose of the present application is to propose a base preparation process, a base and an electronic device packaging tube shell, aiming to solve the problems caused by the use of ceramic packaging in the prior art.

[0008] To achieve the above objectives, on the one hand, the present application provides a base preparation process, wherein the base is used to install an electronic device in an electronic device packaging tube shell, comprising the following steps:

[0009] forming a substrate of a diamond / copper composite material;

[0010] Performing a primary metallization on the surface of the substrate to form a first metal layer;

[0011] Grinding and polishing the surface of the first metal layer;

[0012] Performing secondary metallization on the surface of the first metal layer to form a second metal layer; and

[0013] The surface of the second metal layer is ground and polished.

[0014] In some embodiments, in the step of forming a substrate of the diamond / copper composite material, the substrate is prepared by a high temperature and high pressure method, a vacuum hot pressing sintering method, a spark plasma sintering method or a melt infiltration method.

[0015] In some embodiments, in the step of forming the substrate of the diamond / copper composite material, diamond powder and copper are melted and poured into a molding mold matching the shape of the desired base to obtain the substrate.

[0016] In some embodiments, the structure of the molding die forms a groove on the substrate, and the groove forms a mounting groove after the base is prepared. The mounting groove surrounds a middle area on the base for mounting electronic devices.

[0017] In some embodiments, the first metal layer is formed on the surface of the substrate by an electroplating process, and the first metal layer is formed of one of Ni metal, Ti metal, and TiW alloy.

[0018] In some embodiments, the thickness of the first metal layer is between 7 μm and 10 μm.

[0019] In some embodiments, the second metal layer is formed on the surface of the first metal layer by electroplating or sputtering, and the second metal layer is formed of one of Au metal, Ag metal, and TiAu alloy.

[0020] In some embodiments, the thickness of the second metal layer is greater than 3 μm.

[0021] On the other hand, the present application provides a base, which is prepared using the base preparation process as described above.

[0022] On the other hand, the present application provides an electronic device packaging tube shell, including the base, bottom frame, side frame and top cover as described above; a mounting groove is opened around the middle area of ​​the base for mounting the electronic device, and the lower end of the bottom frame is embedded and installed in the mounting groove; the side frame is installed on the bottom frame, and the top cover is covered on the bottom frame and the side frame.

[0023] The base preparation process, base and electronic device packaging tube shell of the present application have at least the following beneficial effects: in the base preparation process, base and electronic device packaging tube shell of the present application, the base adopts a diamond / copper composite material base, and the high thermal conductivity, low expansion coefficient and low density of the diamond / copper composite material can solve the problems of heat dissipation, flatness and weight; the first metal layer and the second metal layer can improve the surface morphology of the diamond / copper composite material base, which can effectively improve the reliability of electronic device packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the three-dimensional structure of an electronic device packaging tube shell according to an embodiment of the present application;

[0025] Figure 2 for Figure 1 A schematic diagram of the three-dimensional structure of the electronic device packaging tube shell after removing the top cover and the side frame;

[0026] Figure 3 for Figure 1 A schematic diagram of the three-dimensional structure of the side frame of the electronic device packaging tube shell from another angle;

[0027] Figure 4 for Figure 1 A schematic diagram of the three-dimensional structure of the electronic device packaging tube shell after removing the top cover;

[0028] Figure 5 for Figure 1 A schematic diagram of the three-dimensional structure of the top cover of the electronic device packaging tube shell from another angle;

[0029] Figure 6 A schematic diagram of the exploded structure of packaging an electronic device using an electronic device packaging tube shell according to an embodiment of the present application;

[0030] Figure 7 A schematic structural diagram of a cross section of a base after chip mounting is performed on an electronic device packaging tube shell according to an embodiment of the present application;

[0031] Figure 8 It is a schematic diagram of the cross-sectional structure after the base is prepared in the base preparation process implemented in the present application;

[0032] Fig. 9 It is a schematic diagram of the cross-sectional structure after the first metal layer is formed in the base preparation process implemented in the present application;

[0033] Fig.10 This is a schematic diagram of the cross-sectional structure of the first metal layer after grinding and polishing in the base preparation process implemented in the present application;

[0034] Fig.11 This is a schematic diagram of the cross-sectional structure of the second metal layer after grinding and polishing in the base preparation process implemented in the present application;

[0035] Fig.12 It is a schematic diagram of the cross-sectional structure of forming a mounting groove in a base preparation process implemented in the present application.

[0036] Package tube shell 100;

[0037] Base 10; substrate 11, first metal layer 12, second metal layer 13; middle area 14; mounting groove 15;

[0038] Bottom frame 20;

[0039] Side frame 30; frame strip 31, first notch 32;

[0040] Top cover 40; cover plate 41, side wall 42, groove 43, second notch 44;

[0041] A first lead-out terminal 50;

[0042] A second lead-out terminal 60;

[0043] Electronic device 200;

[0044] Bonding layer 300. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the scheme in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments in 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.

[0046] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0047] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0048] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0049] The present application provides a base preparation process, a base and an electronic device packaging shell. The base adopts a diamond / copper composite material as a base. The thermal conductivity of the diamond / copper composite material can be greater than 500W / (m·K). The high thermal conductivity improves the heat dissipation capacity. After a metal layer is formed on the surface of the diamond / copper composite material base, it is mechanically polished and cleaned to achieve the flatness of the base surface. When electronic devices such as chips are mounted, the contact quality between the chip metal and the base is better. Therefore, the electronic device packaging shell and the electronic device packaging method are used to package electronic devices such as GaN HEMT (gallium nitride high electron mobility transistor), which can achieve good heat dissipation performance and good mounting quality. In addition, the diamond / copper composite material also has the characteristic of low density. The density of pure copper is about 8.9g / cm 3 The density of diamond / copper composite materials can reach 5.2-5.5 g / cm 3 Therefore, in fields with high weight sensitivity such as aerospace, its advantages in use are more obvious.

[0050] See also Figures 1 to 4 The structure of an electronic device package tube shell of an embodiment of the present application is shown in the figure. The package tube shell 100 includes a base 10, a bottom frame 20, a side frame 30 and a top cover 40; the base 10 is arranged at the bottom, and the electronic device is mounted on the base 10; the bottom frame 20 is mounted on the base 10, and the side frame 30 is mounted on the bottom frame 20, and the bottom frame 20 and the side frame 30 surround the electronic device 200; the top cover 40 is covered on the bottom frame 20 and the side frame 30. The package tube shell 100 can encapsulate the electronic device 200 mounted on the base 10 by means such as patch.

[0051] like Figure 2 As shown in FIG, the base 10 is surrounded by a bottom frame 20 in the middle area 14, and the lower end of the bottom frame 20 is assembled in a mounting groove 15 formed by a depression near the edge of the base 10 (see FIG. Fig.12 the upper end of the bottom frame 20 protrudes upward from the upper surface of the base 10 and surrounds the middle area 14 on the base 10 for placing the electronic device 200.

[0052] The first lead-out terminal 50 and the second lead-out terminal 60 are bonded to the bottom frame 20. The first lead-out terminal 50 and the second lead-out terminal 60 can be an input lead-out terminal and an output lead-out terminal, respectively. The first lead-out terminal 50 and the second lead-out terminal 60 can be interconnected with the electrodes of the electronic device 200 (e.g., the surface of the patch chip) on the base 10 through wire bonding. The first lead-out terminal 50 and the second lead-out terminal 60 can be respectively arranged on two opposite sides of the bottom frame 20. In the illustrated embodiment, the first lead-out terminal 50 and the second lead-out terminal 60 use a flexible film circuit board, and the lead-out terminal on one side of the first lead-out terminal 50 and the second lead-out terminal 60 on both sides is cut into a shape, so that the first lead-out terminal 50 and the second lead-out terminal 60 have different shapes, so as to distinguish the first lead-out terminal 50 and the second lead-out terminal 60. The bottom frame 20 is made of ceramic and is used to isolate the first lead-out terminal 50 and the second lead-out terminal 60 from the base 10.

[0053] like Figure 3 and Figure 4 As shown in , the side frame 30 is mounted on the bottom frame 20 and presses the first lead-out terminal 50 and the second lead-out terminal 60. The outer circumferential dimension of the side frame 30 is smaller than the outer circumferential dimension of the bottom frame 20, and the inner circumferential dimension of the side frame 30 is larger than the inner circumferential dimension of the bottom frame 20, that is, the periphery of the side frame 30 is smaller than the periphery of the bottom frame 20, and the inner periphery of the side frame 30 is larger than the inner periphery of the bottom frame 20, and the bottom frame 20 and the side frame 30 form steps on both inner and outer sides around the electronic device 200 placed in the middle area 14.

[0054] In the illustrated embodiment, Figure 3 As shown in , the side frame 30 is rectangular and is surrounded by four frame bars 31 , wherein two opposite frame bars 31 are formed with first notches 32 on the surfaces in contact with the bottom frame 20 .

[0055] like Figure 5 As shown in , the circumferential dimension of the top cover 40 is the same as that of the bottom frame 20, that is, when the top cover 40 is covered on the bottom frame 20, the edge of the top cover 40 is aligned with the edge of the bottom frame 20 in the up-down direction. The top cover 40 includes a top cover plate 41 and a side enclosure 42 extending downward from the edge of the cover plate 41, and the side enclosure 42 is a double-walled side enclosure, and a groove 43 is formed between the double walls of the side enclosure 42. The height, thickness, shape and size of the groove 43 match those of the side frame 30, so that when the cover plate 40 is covered on the bottom frame 20, the side frame 30 is embedded in the groove 43, that is, the side enclosure 42 clamps the side frame 30 in the middle groove 43 from both inside and outside, so that the overall sealing can be improved.

[0056] In the illustrated embodiment, the side periphery 42 of the top cover 40 is in the form of a square frame, and at positions corresponding to the first notches 32, second notches 44 are formed on two opposite sides of the side periphery 42, so that when the bottom cover 40 is placed on the bottom frame 20 for sealing, the first notches 32 and the second notches 44 are aligned to form an exhaust port from the inside to the outside of the package tube shell 100. The exhaust port formed by the first notches 32 and the second notches 44 is used for internal exhaust during the sealing process, which can prevent the top cover 40, the side frame 30 and the bottom frame 20 from being unable to closely contact the bottom plate 10 due to the thermal expansion of the internal gas when heating the sealing, and also cause the top cover 40 to shift, thereby causing the poor airtightness of the package tube shell 100 and the problem of difficult automated operation.

[0057] The bottom frame 20 , the side frame 30 and the top cover 40 are all ceramic frames, which can be formed into a desired shape by ceramic sintering.

[0058] like Figure 6 As shown in FIG. 1 , when the electronic device 200 is packaged by the packaging tube shell 100, the electrodes on the surface of the electronic device 200 can be interconnected with the electrodes on the surface of the chip by wire bonding, and the electronic device 200 can be attached to the middle area 14 on the upper surface of the base 10 by glue, or soldered to the middle area 14 on the upper surface of the base 10 by solder, and a bonding layer 300 is formed between the middle area 14 and the metal material of the electronic device 200 (see FIG. 1 ). Figure 7 ).

[0059] The electronic device 200 takes a chip as an example to illustrate different combining methods.

[0060] If you want to improve thermal conductivity when mounting the chip, you can use nano silver glue for mounting. Before mounting, you need to use chemical agents to perform a secondary micro-roughening on the middle area 14 on the upper surface of the base 10 to ensure the adhesion of the nano silver glue and also ensure good thermal conductivity and heat dissipation performance.

[0061] If the bonding strength is required during chip patch packaging, a solder sheet can be used for eutectic patch soldering. There is no need to perform secondary micro-roughening on the base 10 before soldering, which can meet the requirements of heat dissipation and bonding strength at the same time.

[0062] Please refer to Figure 7 The base 10 adopts a base 11 of a diamond / copper composite material (Diamond / Copper composites, Dia / Cu), the surface of the base 11 has a first metal layer 12, and the surface of the first metal layer 12 is provided with a second metal layer 13. That is, the base 10 has a five-layer structure, including a middle diamond copper base 11 and the first metal layer 12 and the second metal layer 13 on both sides of the base 11.

[0063] The base 11 as the main body of the base 10 is made of diamond / copper composite material. Compared with the traditional flange material, the diamond / copper composite material has a higher thermal conductivity, greater than 500W / (m·K), and a low thermal expansion coefficient, about 5.5-6.5×10 -6 / K. For example, when the volume percentage of diamond is 35%, the thermal conductivity of the diamond / copper composite material is as high as 602W / (m·K), and the thermal conductivity is better than that of the traditional flange base, which can meet the thermal conductivity requirements of high-power electronic devices, such as gallium nitride devices, during operation. The base 10 using the diamond / copper composite material can be used as a heat sink for high-power chips, which can effectively reduce the chip junction temperature and improve the reliability and service life of the chip.

[0064] The substrate 11 of the diamond / copper composite material can be prepared by high-temperature high-pressure sintering (HTHP), vacuum hot-pressing sintering (VHPS), spark plasma sintering (SPS) and melt infiltration.

[0065] The first metal layer 12 covers the surface of the substrate 11, and can be formed on the surface of the substrate 11 by an electroplating process, and the metal with uneven outer surface is ground flat by a metal grinding process. The thickness of the first metal layer 12 is preferably between 7 μm and 10 μm, and the first metal layer 12 can be formed of metal materials such as nickel (Ni metal), titanium (Ti metal), titanium tungsten alloy (TiW alloy), etc.

[0066] The second metal layer 13 covers the surface of the first metal layer 12, and can be formed on the surface of the first metal layer 12 by electroplating or sputtering, and the flatness of the outer surface is ensured by grinding and cleaning. The thickness of the second metal layer 13 is preferably greater than 3 μm, and the second metal layer 13 can be formed of metal materials such as gold (Au metal), silver (Ag metal), titanium gold alloy (TiAu alloy), etc.

[0067] In the base 10 , the first metal layer 12 (eg Ni metal) and the second metal layer 13 (eg Au metal) can improve the surface morphology of the base 11 of the diamond / copper composite material, thereby effectively improving the reliability of the packaged electronic device 200 patch.

[0068] The present application also provides an electronic device packaging method using the above packaging tube shell 100. The electronic device packaging method of the present application includes the following steps:

[0069] S1, prepare the base 10, the bottom frame 20, the side frame 30 and the top cover 40 respectively;

[0070] S2, installing the bottom frame 20 onto the base 10;

[0071] S3, installing the electronic device 200 to the middle area 14 of the base 10, and connecting the electrodes of the electronic device 200 to the first lead-out terminal 50 and the second lead-out terminal 60;

[0072] S4, bonding the first lead-out terminal 50 and the second lead-out terminal 60 to the bottom frame 20 and leading them to the outside;

[0073] S5, installing the side frame 30 on the bottom frame 20 and pressing the first lead-out terminal 50 and the second lead-out terminal 60;

[0074] S6, installing the top cover 40 on the bottom frame 20 to seal the cover.

[0075] Please refer to Figures 8 to 11 The steps of preparing the base 10 of the electronic device packaging method will be described in more detail below with reference to the accompanying drawings.

[0076] In step S1, refer to Figures 8 to 12 The base preparation process of an embodiment of the present application includes the following steps:

[0077] S1.11, preparing a diamond / copper composite material substrate 11.

[0078] The substrate 11 is formed by melting diamond powder and copper and pouring the mixture into a molding die that matches the shape of the desired base. Figure 8 as shown in .

[0079] S1.12, performing a primary metallization on the surface of the substrate 11 to form a first metal layer 12.

[0080] In the process of preparing the substrate 11, due to the high hardness of diamond, its surface becomes uneven. Figure 8 A first metal layer 12 is formed on the surface by electroplating process, and the thickness of the first metal layer 12 is between 7 μm and 10 μm, ensuring that the thickness is greater than the depth of the surface pit of the substrate 11 and is higher by more than 5 μm, as shown in FIG. Figure 7 The metal forming the first metal layer 12 may be Ni, Ti, TiW or the like.

[0081] S1.13, grinding and polishing the surface of the first metal layer 12.

[0082] After the first metal layer 12 is formed, the metal surface is ground flat using a metal grinding process. During grinding, attention should be paid to the flatness of the surface to ensure that there is no uneven change in the middle area 14 (i.e., the patch area of ​​the electronic device 200) after grinding. After grinding, the surface needs to be cleaned to remove the metal powder generated during the grinding process. After grinding and cleaning, Fig.10 as shown in .

[0083] S1.14, secondary metallization is performed on the surface of the first metal layer 12 to form a second metal layer 13.

[0084] A second metal layer 13 is formed on the surface of the first metal layer 12. The second metal layer 13 may be formed by electroplating, sputtering, etc. Since the surface of the substrate 11 has been metallized by the first metal layer 12, the thickness of the second metal layer 13 does not need to be too large, and can be greater than 3 μm. The metal forming the second metal layer 13 may be Au, Ag, TiAu, etc.

[0085] S1.15, the surface of the second metal layer 13 is ground and polished.

[0086] After the second metal layer 13 is formed, the surface is subjected to secondary grinding and surface cleaning to ensure the surface flatness. Fig.11 as shown in .

[0087] The base 10 prepared through the above steps is ground twice to ensure that the height difference between the center and the edge of the middle area 14 of the base 10 is less than 5 μm.

[0088] In step S1 , the side frame 30 and the top cover 40 are manufactured by a ceramic sintering process to form a desired shape.

[0089] In step S3 , a bonding layer 300 is formed between the electronic device 200 and the second metal layer 13 on the surface of the base 10 and fixed to the middle region 14 .

[0090] More specifically, when performing chip packaging of the electronic device 200, nanosilver glue can be used for chip packaging. Before chip packaging, it is necessary to use chemical agents to perform additional secondary micro-roughening on the middle area 14 on the upper surface of the base 10 to ensure the adhesion effect of the nanosilver glue and also ensure good thermal conductivity and heat dissipation performance, which is suitable for occasions that pursue thermal conductivity. When performing chip chip packaging, solder sheets can also be used for eutectic soldering. Before welding, there is no need to perform secondary micro-roughening on the middle area 14 of the base 10, which can meet the requirements of heat dissipation and bonding firmness at the same time, and is suitable for occasions that pursue more bonding firmness.

[0091] In step S6, when sealing, the gas expanded by heat can be discharged to the outside through the exhaust port formed by the first notch 32 and the second notch 44 inside the packaging tube shell 100, thereby avoiding problems such as loose contact and displacement caused by thermal expansion of the gas, improving the poor airtightness of the packaging tube shell 100, and being suitable for packaging the electronic device 200 by automated operation.

[0092] See also Fig.12 As mentioned above, the bottom frame 20 is installed in the installation groove 15 formed around the middle area 14 on the base 10. Therefore, in the process of preparing the base 11 of the diamond / copper composite material in step S1, the structural design of the molding mold can form a groove on the base 11 of the diamond / copper composite material corresponding to the position where the bottom frame 20 is installed. After the subsequent preparation steps of forming the first metal layer 12 and the second metal layer 13, the groove forms the installation groove 15. In this way, the installation groove 15 can be directly formed without additional mechanical processing. Therefore, in the process of installing the ceramic bottom frame 20, the side of the bottom frame 20 can be embedded into the inside of the base 11 in a mosaic manner to improve the airtightness and stability of the package tube shell 100.

[0093] In summary, the base preparation process, base and electronic device packaging shell of the present application have at least the following advantages:

[0094] (1) In the base preparation process, base and electronic device packaging tube shell of the present application, the base adopts a diamond / copper composite material base. The high thermal conductivity, low expansion coefficient and low density of the diamond / copper composite material can solve the problems of heat dissipation, flatness and weight; the first metal layer and the second metal layer improve the surface morphology of the diamond / copper composite material base, which can effectively improve the reliability of electronic device packaging.

[0095] (2) The grinding and polishing of the first metal layer and the second metal layer can reduce the flatness problem of the base of the diamond / copper composite material during the preparation process, effectively improve the reliability of the electronic device attached to the base, and reduce the dependence on the thickness of the solder during welding.

[0096] (3) By providing a mounting groove in the base of the diamond / copper composite material, the bottom frame can be embedded with the base, thereby improving the airtightness and stability of the package shell.

[0097] The above description is only a partial or preferred embodiment of the present application. Neither the text nor the drawings can limit the scope of protection of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the overall concept of the present application, or direct / indirect application in other related technical fields are included in the scope of protection of the present application.

Claims

1. A base preparation process, wherein the base (10) is used to install an electronic device (200) in an electronic device packaging tube shell, characterized in that: The following steps are involved: forming a substrate (11) of a diamond / copper composite material; Performing a primary metallization on the surface of the substrate (11) to form a first metal layer (12); Grinding and polishing the surface of the first metal layer (12); Performing secondary metallization on the surface of the first metal layer (12) to form a second metal layer (13); and The surface of the second metal layer (13) is ground and polished.

2. The base preparation process according to claim 1, characterized in that: In the step of forming a substrate (11) of a diamond / copper composite material, the substrate (11) is prepared by a high temperature and high pressure method, a vacuum hot pressing sintering method, a spark plasma sintering method or a melt infiltration method.

3. The base preparation process according to claim 1, characterized in that: In the step of forming the diamond / copper composite material substrate (11), diamond powder and copper are melted and poured into a molding die matching the shape of the desired base to obtain the substrate (11).

4. The base preparation process according to claim 3, characterized in that: The structure of the molding die forms a groove on the base (11), and the groove forms a mounting groove (15) after the base (10) is prepared. The mounting groove (15) surrounds a middle area (14) on the base (10) for mounting an electronic device (200).

5. The base preparation process according to claim 1, characterized in that: The first metal layer (12) is formed on the surface of the substrate (11) by an electroplating process, and the first metal layer (12) is formed from one of Ni metal, Ti metal, and TiW alloy.

6. The base preparation process according to claim 5, characterized in that: The thickness of the first metal layer (12) is between 7 μm and 10 μm.

7. The base preparation process according to claim 1, characterized in that: The second metal layer (13) is formed on the surface of the first metal layer (12) by electroplating or sputtering, and the second metal layer (13) is formed of one of Au metal, Ag metal, and TiAu alloy.

8. The base preparation process according to claim 7, characterized in that: The thickness of the second metal layer (13) is greater than 3 μm.

9. A base, characterized in that: The base (10) is prepared by using the base preparation process according to any one of claims 1 to 8.

10. An electronic device packaging tube shell, characterized in that: The electronic device comprises a base (10), a bottom frame (20), a side frame (30) and a top cover (40) according to claim 9; a mounting groove (15) is provided around a middle area (14) of the base (10) for mounting an electronic device (200), and the lower end of the bottom frame (20) is embedded in the mounting groove (15); the side frame (30) is mounted on the bottom frame (20), and the top cover (40) is covered on the bottom frame (20) and the side frame (30).

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