Method for forming conductive layer, conductive structure and method for forming conductive layer

Abstract

The embodiment of the present invention provides a method for forming a conductive layer, a conductive structure and a method for forming the conductive layer, the method for forming the conductive layer includes: providing a first conductive film and a solution having a conductive material; coating the solution on the surface of the first conductive film, and before the coating, the temperature of the first conductive film is lower than the evaporation temperature or sublimation temperature of the solution; in the process step of coating or after the coating, heating the first conductive film so that the temperature of the first conductive film is higher than or equal to the evaporation temperature or sublimation temperature of the solution, forming a second conductive film covering the surface of the first conductive film, the second conductive film including the conductive material. The present invention is conducive to improving the structural stability and conductive performance of the conductive layer.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor device manufacturing, and in particular to a method for forming a conductive layer, a conductive structure and a method for forming the same. Background Art

[0002] In semiconductor devices, the conductive layer plays a role in signal transmission and power transmission. In the pre-process of semiconductor devices, other electrical components in the semiconductor device are often tested for electrical properties through the conductive layer to ensure that the tested electrical components have the preset electrical properties.

[0003] However, multiple electrical tests may cause damage to the conductive layer, thereby affecting the electrical properties of the conductive layer itself. Summary of the invention

[0004] The embodiments of the present invention provide a method for forming a conductive layer, a conductive structure and a method for forming the same, which are beneficial to make up for the performance defects of an initial conductive film and improve the conductive performance of the conductive layer.

[0005] To solve the above problems, an embodiment of the present invention provides a method for forming a conductive layer, comprising: providing a first conductive film and a solution having a conductive material; coating the solution on the surface of the first conductive film, and before the coating, the temperature of the first conductive film is lower than the evaporation temperature or sublimation temperature of the solution; in the coating process step or after the coating, heating the first conductive film so that the temperature of the first conductive film is greater than or equal to the evaporation temperature or sublimation temperature of the solution, to form a second conductive film covering the surface of the first conductive film, the second conductive film comprising the conductive material.

[0006] In addition, the first conductive film has a damaged surface; the solution is applied on the damaged surface; after the coating, the second conductive film covering the damaged surface is formed.

[0007] In addition, in the process step of heating the first conductive film, the temperature of the first conductive film is lower than the melting point of the first conductive film.

[0008] In addition, the material of the first conductive film includes aluminum; in the process step of heating the first conductive film, the temperature of the first conductive film is lower than or equal to 400°C.

[0009] In addition, the heating the first conductive film includes: heating the first conductive film so that the temperature of the first conductive film is higher than or equal to the melting point of the conductive material.

[0010] In addition, the solution can dissolve the material of the first conductive film; and the second conductive film includes the material of the first conductive film.

[0011] Additionally, the solution includes an amalgam.

[0012] In addition, heating the first conductive film includes: heating the first conductive film so that the temperature of the first conductive film is higher than or equal to 36° C.

[0013] Correspondingly, an embodiment of the present invention also provides a method for forming a conductive structure, comprising: providing a first conductive film and a solution having a conductive material; coating the solution on the surface of the first conductive film, and when the coating is performed, the temperature of the first conductive film is lower than the evaporation temperature or sublimation temperature of the solution; in the process step of performing the coating or after the coating, heating the first conductive film so that the temperature of the first conductive film is higher than the evaporation temperature or sublimation temperature of the solution, forming a conductive bump located on the first conductive film, and the top surface of the conductive bump is higher than the top surface of the first conductive film.

[0014] In addition, the solution is coated on the surface of the first conductive film multiple times, and between two adjacent coatings, the temperature of the first conductive film is higher than or equal to the evaporation temperature or sublimation temperature of the solution to form the conductive bump comprising multiple layers of conductive films stacked in sequence.

[0015] In addition, the solution is coated on the surface of the first conductive film multiple times, and between two adjacent coatings, the temperature of the first conductive film is lower than the evaporation temperature or sublimation temperature of the solution to form the conductive bump comprising a single-layer conductive film.

[0016] In addition, the solution is applied by dropper dropping or screen printing.

[0017] Correspondingly, an embodiment of the present invention further provides a conductive structure, including: a first conductive film and a conductive bump located on the first conductive film, wherein the sidewall morphology of the conductive bump includes a curved surface.

[0018] In addition, the conductive bump includes a plurality of conductive films stacked in sequence, and the sidewall morphology of the conductive bump includes a wave shape.

[0019] In addition, the conductive films in different layers have different conductive materials, or the proportions of the same conductive material in the conductive films in different layers are different.

[0020] Compared with the prior art, the technical solution provided by the embodiment of the present invention has the following advantages:

[0021] In the above technical scheme, a coating process is adopted to coat a solution on the surface of the first conductive film, and by controlling the temperature of the first conductive film during the coating process, the solution having the conductive material can be evenly distributed on the surface of the first conductive film and fully contact the surface of the first conductive film. The entire process can be carried out in a low temperature environment without the need to use a high temperature process. For example, a high temperature reflux process is used to melt the conductive material to form a melt, which is beneficial to avoid damage to the first conductive film and other adjacent components caused by the high temperature environment, thereby ensuring that the finally formed conductive layer and adjacent components have good performance.

[0022] In addition, the solution can dissolve the material of the first conductive film, so that an alloy can be formed at the junction of the first conductive film and the second conductive film, which is beneficial to increase the bonding strength between the first conductive film and the second conductive film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplifications do not constitute limitations on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute proportional limitations.

[0024] Figures 1 to 3 A schematic cross-sectional structure diagram corresponding to each step of a method for forming a conductive layer provided by an embodiment of the present invention;

[0025] Figures 4 to 8 A schematic cross-sectional structure diagram corresponding to each step of a method for forming a conductive structure provided by an embodiment of the present invention;

[0026] Figures 9 and 10 A schematic cross-sectional structure diagram corresponding to each step of a method for forming a conductive structure provided by another embodiment of the present invention;

[0027] Fig.11 A schematic cross-sectional view of a conductive structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the embodiments of the present invention, many technical details are provided to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can be implemented.

[0029] Figures 1 to 3 A schematic cross-sectional structure diagram corresponding to each step of a method for forming a conductive layer provided by an embodiment of the present invention.

[0030] refer to Figure 1, providing a first conductive film 11 and a solution 13 having a conductive material.

[0031] In this embodiment, the first conductive film 11 may be a metal pad (I / O Bonding Pad) formed in the substrate 10, such as a bonding pad, and the metal pad is one of the transmission paths for power transmission and control signal transmission. A protective layer 12 is formed on the substrate 10, and the protective layer 12 has an opening that exposes the surface of the first conductive film 11. The protective layer 12 is used to protect the substrate 10 and the components located on the surface of the substrate 10; in addition, the protective layer 12 also covers part of the surface of the first conductive film 11, and plays a role in fixing the first conductive film 11.

[0032] In this embodiment, the first conductive film 11 has a damaged surface 111, and the defects of the damaged surface 111 are mainly manifested as multiple grooves with different depth-to-width ratios. The grooves include needle marks formed when the probe improperly contacts the first conductive film 11 during electrical testing. Compared with grooves formed by other damages, such as friction damage, the needle mark grooves formed by the probe miscontacting have a higher depth-to-width ratio.

[0033] In this embodiment, the type of conductive material in the solution 13 is related to specific requirements. For example, when the finally formed conductive layer (including the first conductive film 11 and the second conductive film formed subsequently) is required to have good conductivity, the conductive material has a higher conductivity. Generally speaking, the conductive material is the same as the material of the first conductive film 11, or, for specific requirements, the conductive material is superior to the material of the first conductive film 11 in a certain specific property.

[0034] It should be noted that the conductive material of the solution 13 is not necessarily a single metal material, but may be a plurality of metal materials. When the solution 13 contains a plurality of conductive materials, the second conductive film finally formed is in an alloy state.

[0035] In this embodiment, the solution 13 can dissolve a variety of conductive materials including the material of the first conductive film 11. After the solution 13 is applied to the surface of the first conductive film 11, it will first dissolve part of the material of the first conductive film 11, so that the second conductive film formed by the subsequent precipitation of the conductive material includes the material of the first conductive film 11.

[0036] Since the solution 13 can dissolve the material of the first conductive film 11, the coating of the solution 13 is conducive to reducing the aspect ratio of the groove in the damaged surface 111, so that the solution 13 can more fully fill the groove. In this way, it is conducive to reducing the gap or void between the second conductive film and the first conductive film 11 formed subsequently, increasing the contact area between the first conductive film 11 and the second conductive film, thereby improving the bonding strength between the first conductive film 11 and the second conductive film, and reducing the resistance of the contact surface between the first conductive film 11 and the second conductive film, so that the conductive layer has higher structural stability and conductivity.

[0037] In addition, since the solution 13 can dissolve the material of the first conductive film 11, an alloy can be formed at the junction of the first conductive film 11 and the second conductive film formed subsequently, which is beneficial to enhance the bonding strength between the first conductive film 11 and the second conductive film and improve the structural stability of the conductive layer.

[0038] In this embodiment, the solution 13 includes amalgam. Mercury (i.e., mercury) can dissolve various metals to form amalgam, such as copper, silver, gold, and aluminum; at the same time, the various metals in the amalgam can be precipitated by heating the amalgam, and the precipitated metals can form a well-fitting alloy with the metal in contact with the amalgam.

[0039] It should be noted that the conductive material contained in the solution 13 will affect the temperature required for the solution 13 to start evaporation or sublimation. Therefore, when the first conductive film 11 is heated, the temperature of the first conductive film 11 needs to be adjusted according to the type of solution and the conductive material contained therein so that the conductive material contained therein can be completely precipitated. In this embodiment, the solution 13 is amalgam; the temperature of the first conductive film 11 after heating should be greater than or equal to 36°C.

[0040] In this embodiment, the solution 13 is applied by dripping with a dropper 14. During the application of the solution 13, it is only necessary to control the position of the dropper 14 relative to the first conductive film 11, and control the amount of the solution 13 applied each time by controlling the squeezing amount of the dropper 14, so that precise coating can be achieved to completely fill the grooves in the damaged surface 111.

[0041] Compared with the prior art which requires a high temperature process to form a metal melt, the process steps mentioned in this scheme can be carried out in a low temperature environment, which is beneficial to avoid damage to the first conductive film 11 and other adjacent components caused by the high temperature environment, and ensure that the finally formed conductive layer and adjacent components have good performance.

[0042] In addition, compared to forming a conductive layer by an electroplating process, forming a conductive layer by a coating process does not require forming additional side walls to limit the metal deposition position during the electroplating process, nor does it require setting up electroplating liquid, electroplating tank, anode and other materials or devices for electroplating, which is beneficial to reducing process complexity and reducing process costs.

[0043] refer to Figure 2 , the solution 13 is coated on the surface of the first conductive film 11 , and before the coating, the temperature of the first conductive film 11 is lower than the evaporation temperature or sublimation temperature of the solution 13 .

[0044] Because the temperature of the first conductive film 11 is lower than the evaporation temperature or sublimation temperature of the solution 13 before coating, the solution 13 can flow freely for a period of time after contacting the surface of the first conductive film 11, and then be evenly distributed on the surface of the first conductive film 11. This is conducive to improving the uniformity of the conductivity of different positions of the conductive layer formed subsequently, and ensuring that the conductive layer has high performance stability.

[0045] In this embodiment, the solution 13 is applied to the damaged surface 111 (refer to Figure 1 ). Since the solution 13 has a certain free flow time, the solution 13 can fill the grooves in the damaged surface 111 to a certain extent or even completely. In this way, it is helpful to reduce or even eliminate the gaps or holes between the second conductive film and the first conductive film 11 formed subsequently, increase the contact area between the first conductive film 11 and the second conductive film, reduce the resistance of the conductive layer composed of the first conductive film 11 and the second conductive film, and improve the bonding strength of the first conductive film 11 and the second conductive film, thereby improving the comprehensive performance of the conductive layer.

[0046] In addition, coating the damaged surface 111 with the solution 13 to eliminate the grooves on the damaged surface 111 is beneficial to ensure that the wire and the metal pad have a high degree of bonding during subsequent wire bonding, that is, the wire and the metal pad have a high bonding strength and the bonding surface has a low resistance.

[0047] It should be noted that the larger the aspect ratio of the groove is, the longer the free flow time required to fill the groove is. In this embodiment, the free flow time of the solution 13 can be controlled by controlling the time difference between the coating time of the solution 13 and the time when the first conductive film 11 is heated to the evaporation temperature or the sublimation temperature.

[0048] refer to Figure 3 In the coating process step or after the coating, the substrate 10 is heated so that the temperature of the first conductive film 11 is greater than or equal to the solution 13 (reference Figure 2 ) to form a second conductive film 15 covering the surface of the first conductive film 11, wherein the material of the second conductive film 15 includes the conductive material contained in the solution 13.

[0049] It should be noted that the time when the temperature of the first conductive film 11 reaches the evaporation temperature or the sublimation temperature is not equal to the time when the substrate 10 starts to be heated. The time when the substrate 10 starts to be heated may be during the coating process, or before or after the coating process.

[0050] In this embodiment, the substrate 10 is heated by a heating stage 16 disposed below the substrate 10. This helps ensure that the first conductive film 11 can be heated evenly, so that the solutions 13 at different positions can evaporate or sublime at the same time, and avoid the first precipitated conductive material blocking the flow of the remaining solution 13, thereby ensuring that the solution 13 can be evenly distributed on the surface of the first conductive film 11 and effectively fill the grooves on the damaged surface.

[0051] In this embodiment, in the process step of heating the first conductive film 11, the temperature of the first conductive film 11 is lower than the melting point of the first conductive film 11. This is conducive to preventing the solution 13 from mixing with the melted material of the first conductive film 11, ensuring that the solution 13 can evaporate or sublime normally, and further ensuring that the finally formed conductive layer has good performance.

[0052] In other embodiments, when the flow of the material of the first conductive film after melting does not affect the performance of the conductive layer, or the solution can evaporate or sublime well under mixing, or the solution material does not affect the performance of the conductive layer, in the process of heating the first conductive film, the temperature of the first conductive film can be higher than or equal to the melting point of the first conductive film.

[0053] In this embodiment, the material of the first conductive film 11 includes aluminum; in the process step of heating the first conductive film 11, the temperature of the first conductive film 11 is lower than or equal to 400° C. Since aluminum is easily deformed by external force in a temperature environment greater than 400° C., controlling the temperature of the first conductive film 11 below 400° C. is beneficial to avoid the coating process of the solution 13 affecting the shape and structure of the first conductive film 11, thereby ensuring that the finally formed conductive layer has good performance.

[0054] In this embodiment, the substrate 10 is heated so that the temperature of the first conductive film 11 is higher than or equal to the melting point of the conductive material in the solution 13. Compared with solid conductive materials, liquid conductive materials are more easily distributed on the surface of the first conductive film 11, and are more easily repaired on the damaged surface of the first conductive film 11, eliminating the gap or void between the second conductive film 15 and the first conductive film 11, and increasing the contact area between the second conductive film 15 and the first conductive film 11, thereby improving the bonding strength between the second conductive film 15 and the first conductive film 11 and reducing the resistance of the conductive layer, ensuring that the conductive layer has good conductive properties and structural stability.

[0055] It should be noted that in the process step of heating the first conductive film 11, the temperature setting of the first conductive film 11 not only needs to consider the impact of the physical states of different film layers and materials on the performance of the conductive layer finally formed, but also needs to consider the irreversible impact of temperature on the performance of different materials and different components. For example, as the temperature rises, the performance of some components or materials will irreversibly degrade, thereby ensuring that the conductive layer finally formed and the device containing the conductive layer have good performance.

[0056] In this embodiment, the top surface of the second conductive film 15 is higher than the top surface of the first conductive film 11, thereby ensuring that the grooves on the damaged surface are completely filled; in other embodiments, the top surface of the second conductive film is lower than or flush with the top surface of the first conductive film.

[0057] In this embodiment, a coating process is adopted to coat the solution 13 on the surface of the first conductive film 11, and by controlling the temperature of the first conductive film 11 during the coating process, the solution 13 can be evenly distributed on the surface of the first conductive film 11. The entire process can be carried out completely under low temperature conditions, and there is no need to adopt a high temperature process to dissolve the conductive material, which is beneficial to avoid damage to the conductive layer and other components around the conductive layer caused by the high temperature environment.

[0058] Accordingly, an embodiment of the present invention further provides a method for forming a conductive structure.

[0059] The following will be combined Figures 4 to 9 For detailed explanation, Figures 4 to 9 A schematic cross-sectional structure diagram corresponding to each step of a method for forming a conductive structure provided by an embodiment of the present invention.

[0060] refer to Figure 4 , providing a first conductive film 21 , and coating a primary solution 23 on the surface of the first conductive film 21 .

[0061] In this embodiment, the surface of the first conductive film 21 is not damaged, and when the conductive bump is directly formed on the surface of the first conductive film 21, the conductive bump and the first conductive film 21 can have a larger contact area. In this way, the conductive bump has a higher structural reliability, and the contact surface between the conductive bump and the first conductive film 21 has a lower resistance.

[0062] In other embodiments, the first conductive film has a damaged surface, and before forming the conductive bump, a solution needs to be pre-coated to form a second conductive film that completely fills the grooves on the damaged surface. This is beneficial to increase the contact area between the conductive bump and the conductive layer, thereby increasing the bonding strength between the conductive bump and the conductive layer, and reducing the resistance of the contact surface between the conductive bump and the conductive layer.

[0063] In this embodiment, reference Figure 5, a small amount of solution 23 is used for single coating, and the top surface of the conductive film formed by single coating is lower than the top surface of the protective layer 22, and multiple coatings are required to form a conductive bump with a top surface higher than the top surface of the protective layer 22. Using a small amount of solution 23 for single coating is conducive to preventing the protective layer 22 from blocking the dripping of a large amount of solution, thereby ensuring that the conductive bump is in good contact with the first conductive film 21.

[0064] In other embodiments, reference Figure 6 When the depth-width ratio of the opening of the protective layer 42 exposing the first conductive film 41 is relatively small, a large dose of the solution 43 may be directly used for single coating to form a conductive bump containing only a single conductive film on the surface of the first conductive film 41. This is beneficial to shorten the process cycle of the conductive bump.

[0065] In this embodiment, when the solution 23 is applied, the temperature of the first conductive film 21 is lower than the evaporation temperature or sublimation temperature of the solution 23. In this way, the solution 23 can flow freely for a period of time after contacting the first conductive film 21, and then fully contact the surface of the first conductive film 21, that is, the solution 23 can have a larger contact area with the surface of the first conductive film 21, so that the conductive bump formed by the conductive material precipitated from the solution 23 has a larger contact area with the first conductive film 21, so that the conductive bump and the first conductive film 21 have a higher bonding strength, and the contact surface between the conductive bump and the first conductive film 21 has a lower resistance.

[0066] It should be noted that, between the time when the solution 23 is coated on the surface of the first conductive film 21 and the time when the solution 23 begins to evaporate or sublimate, the solution 23 gradually spreads on the surface of the first conductive film 21, that is, the height difference between the top surface of the solution 23 and the top surface of the first conductive film 21 becomes smaller and smaller, and the contact surface between the solution 23 and the first conductive film 21 becomes larger and larger, and the larger the contact surface, the better the structural stability of the conductive bump. In actual application, it is necessary to balance the evaporation or sublimation time of the solution 23 and the structural stability of the conductive bump to select a suitable evaporation or sublimation time, which refers to the time between the time when the solution 23 is coated on the surface of the first conductive film 21 and the time when it begins to solidify.

[0067] refer to Figure 7 and Figure 8 , coating is performed multiple times and the first conductive film 21 is heated to form a conductive bump 24 , the top surface of the conductive bump 24 being higher than the top surface of the first conductive film 21 .

[0068] In this embodiment, since the height of the conductive film obtained by coating the solution 23 once on the top surface of the first conductive film 21 and heating it is lower than the preset height requirement and cannot be directly used as a conductive bump, multiple coating processes are required to obtain a conductive bump that meets the preset height requirement.

[0069] In this embodiment, between two adjacent coatings, the temperature of the first conductive film 21 is lower than the evaporation temperature and sublimation temperature of the solution 23. In this way, the solution 23 coated next time can be fused with the solution 23 coated last time, and after heating the first conductive film 21 to evaporate or sublimate the solution 23, an integrated conductive bump 24 containing only a single layer of conductive film can be formed.

[0070] Since the solutions 23 coated at different times can merge with each other, the finally formed integrated conductive bump 24 has fewer gaps, that is, the conductive bump 24 has better conductive performance.

[0071] In other embodiments, reference Fig. 9 and Fig.10 Between two adjacent coatings, the temperature of the first conductive film 51 is higher than or equal to the evaporation temperature or sublimation temperature of the solution 53, so that the conductive film formed after the conductive material in the solution 53 is precipitated can be quickly stacked to reach a preset height, thereby forming a conductive bump 54 including a multi-layer conductive film. This is conducive to shortening the process cycle of the conductive bump 54.

[0072] In this embodiment, compared with forming the conductive bumps by the electroplating process, the conductive bumps are formed by the coating process. There is no need to form additional side walls to limit the metal deposition position during the electroplating process, and there is no need to set up electroplating liquid, electroplating tank, anode and other materials or devices for electroplating. Only alignment, control of coating amount and timely heating are required, which is conducive to reducing process complexity and reducing process costs.

[0073] Correspondingly, an embodiment of the present invention further provides a conductive structure, which can be manufactured by using the above conductive structure forming method.

[0074] refer to Fig.11 The conductive structure includes a first conductive film 61 and a conductive bump 64 located on the first conductive film 61 , and a sidewall morphology of the conductive bump 64 includes a curved surface.

[0075] In this embodiment, the conductive bump 64 includes a plurality of conductive films stacked in sequence, and the sidewall morphology of the conductive bump 64 includes a wave shape. Since the multi-layer conductive films are often not perfectly fitted, there will always be a certain number of voids or gaps, and these voids and gaps allow technicians to remove this layer of conductive film separately. This makes it possible to remove only one or more layers of conductive film located at the top when the conductive bump 64 is damaged, without removing the entire conductive bump 64. Accordingly, since the undamaged conductive film can be retained, the repair time of the conductive bump 64 can be shortened, and the usable time of the conductive bump 64 can be extended.

[0076] In this embodiment, the conductive materials in different layers of conductive films are the same or different. For example, the conductive bump 64 includes a second conductive film 642 in contact with the first conductive film 61, a third conductive film 643 that is subsequently used as a pressure welding contact point, and a fourth conductive film 644 located in the middle area. The connection strength between the second conductive film 642 and the first conductive film 61 is greater than the connection strength between the third conductive film 643 and the first conductive film 61. The melting point of the fourth conductive film 644 is lower than the melting point of the third conductive film 643. The conductivity of the fourth conductive film 644 is higher than the conductivity of the second conductive film 642 and the third conductive film 643. In this way, it can ensure that the conductive bump 64 has a higher connection strength with the first conductive film 61, and it can also ensure that the conductive bump 64 has a lower resistance, and it can also ensure that the conductive bump 64 can be connected to a chip or other structure at a lower temperature.

[0077] It should be noted that since a single-layer conductive film may contain multiple conductive materials, when the proportion of one of the materials changes, the properties of the conductive film may also change accordingly. Therefore, by adjusting the proportion of the same conductive material in each layer of the conductive film, different conductive films can exhibit different properties when the conductive material composition type is the same.

[0078] In this embodiment, a new conductive structure is provided, and the sidewall morphology of the conductive bump can be a curved surface. When the performance of the conductive bump is damaged, it can be repaired or reformed by various low-cost process methods such as coating, which helps to reduce maintenance costs.

[0079] Those skilled in the art will appreciate that the above embodiments are specific examples of the present invention, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present invention. Any person skilled in the art may make changes and modifications without departing from the spirit and scope of the present invention, and therefore the scope of protection of the present invention shall be subject to the scope defined in the claims.

Claims

1. A method for forming a conductive layer, characterized in that: include: providing a first conductive film and a solution having a conductive material; The solution is coated on the surface of the first conductive film, and before the coating, the temperature of the first conductive film is lower than the evaporation temperature or sublimation temperature of the solution; During the coating process or after the coating, the first conductive film is heated so that the temperature of the first conductive film is higher than or equal to the evaporation temperature or sublimation temperature of the solution, thereby forming a second conductive film covering the surface of the first conductive film, wherein the second conductive film includes the conductive material.

2. The method for forming a conductive layer according to claim 1, wherein: The first conductive film has a damaged surface; the solution is coated on the damaged surface; after the coating, the second conductive film covering the damaged surface is formed.

3. The method for forming a conductive layer according to claim 1, wherein: In the process step of heating the first conductive film, the temperature of the first conductive film is lower than the melting point of the first conductive film.

4. The method for forming a conductive layer according to claim 3, characterized in that: The material of the first conductive film includes aluminum; in the process step of heating the first conductive film, the temperature of the first conductive film is lower than or equal to 400°C.

5. The method for forming a conductive layer according to claim 1 or 3, characterized in that: The heating of the first conductive film includes: heating the first conductive film so that the temperature of the first conductive film is higher than or equal to the melting point of the conductive material.

6. The method for forming a conductive layer according to claim 1, wherein: The solution can dissolve the material of the first conductive film; and the second conductive film includes the material of the first conductive film.

7. The method for forming a conductive layer according to claim 1, wherein: The solution includes an amalgam.

8. The method for forming a conductive layer according to claim 7, characterized in that: The heating the first conductive film includes: heating the first conductive film so that the temperature of the first conductive film is higher than or equal to 36° C.

9. A method for forming a conductive structure, characterized in that: include: providing a first conductive film and a solution having a conductive material; Coating the solution on the surface of the first conductive film, and during the coating, the temperature of the first conductive film is lower than the evaporation temperature or sublimation temperature of the solution; During the coating process or after the coating, the first conductive film is heated so that the temperature of the first conductive film is higher than the evaporation temperature or sublimation temperature of the solution, thereby forming a conductive bump on the first conductive film, wherein the top surface of the conductive bump is higher than the top surface of the first conductive film.

10. The method for forming a conductive structure according to claim 9, characterized in that: The solution is coated on the surface of the first conductive film multiple times, and between two adjacent coatings, the temperature of the first conductive film is higher than or equal to the evaporation temperature or sublimation temperature of the solution to form the conductive bump comprising multiple conductive films stacked in sequence.

11. The method for forming a conductive structure according to claim 9, characterized in that: The solution is coated on the surface of the first conductive film for multiple times, and between two adjacent coatings, the temperature of the first conductive film is lower than the evaporation temperature or sublimation temperature of the solution, so as to form the conductive bump comprising a single-layer conductive film.

12. The method for forming a conductive structure according to claim 9, characterized in that: The solution is applied by dripping with a dropper or by screen printing.

13. A conductive structure formed by the method according to claim 9, characterized in that: include: A first conductive film and a conductive bump located on the first conductive film, wherein a sidewall morphology of the conductive bump includes a curved surface.

14. The conductive structure according to claim 13, characterized in that: The conductive bump includes a plurality of conductive films stacked in sequence, and the sidewall morphology of the conductive bump includes a wave shape.

15. The conductive structure according to claim 14, characterized in that: The conductive films in different layers have different conductive materials, or the proportions of the same conductive material in the conductive films in different layers are different.

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