Conductive Structure, Printing Flattening Method and Equipment for Low-Temperature Conductive Paste

Abstract

The present invention discloses a conductive structure, a method and equipment for printing and flattening a low-temperature conductive paste, and relates to the technical field of additive manufacturing of electronic circuits; the method for printing and flattening the low-temperature conductive paste includes: after forming a printed structure on the surface of a substrate to be printed by using the conductive paste, performing a primary curing treatment on the printed structure so that the volatile substances therein reach a volatile content of 10% to 80%, to obtain a prefabricated structure; performing a pressing treatment on the prefabricated structure so that it is continuously subjected to external pressure extrusion and shaping during the process, to obtain a flattened and optimized structure. After applying the conductive paste to form a printed structure, the present invention sequentially performs a primary curing treatment and a pressing treatment on the printed structure, and by means of the pressing treatment, the influence of the surface tension effect of the conductive paste on the surface flatness is reduced as much as possible, the flatness of the conductive structure is improved, and the gap with the traditional copper clad laminate is narrowed.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic circuit additive manufacturing, and in particular relates to a printing and leveling method and equipment for conductive structures and low-temperature conductive pastes. Background Art

[0002] Low-temperature curing conductive paste, also known as low-temperature conductive paste, is the basic material for the new generation of electronic circuit additive manufacturing technology. It is mainly composed of conductive particles, organic resins, solvents and related additives. Compared with high-temperature conductive pastes with glass powder as the binding phase in the material, it has obvious advantages such as low-temperature controllability and strong universality. It can be patterned by various processes such as direct writing printing, extrusion printing, electric field jetting, spraying, air jetting, screen printing, coating, pad printing, flexographic printing, etc. After molding, only lower conditions are required to complete the curing treatment to obtain a stable conductive structure, which reduces the temperature resistance requirements for the substrate. It can be applied to most circuit substrates and can replace PCB hard boards and FPC soft boards produced by traditional copper cladding etching process.

[0003] Although low-temperature conductive paste has the above advantages, it also has some inherent defects that are difficult to overcome. For example, it is difficult for the printing flatness to achieve the overall high flatness of the copper clad laminate. This is mainly because the conductive paste is still in a flowable paste form when applied, so it is inevitably affected by the surface tension of the fluid. Through high-power microscope observation, it can be found that the surface of the printed circuit will present an arc shape with a high middle and low sides. The poor flatness makes it difficult for the conductive structure produced using conductive paste to meet the needs of high-frequency signals, high-precision patches, chip packaging and other high-precision products and processes. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a printing and flattening method for low-temperature conductive paste to improve the problem of poor surface flatness of printed circuits caused by the surface tension of the conductive paste in the prior art.

[0005] In some illustrative embodiments, the printing and planarization method of the low-temperature conductive paste is applied to a conductive paste with an organic resin as a binder phase, comprising:

[0006] After forming a printed structure on the surface of a printing substrate using a conductive paste, the printed structure is subjected to a curing treatment to volatilize volatile substances therein to a level of 10% to 80%, thereby obtaining a prefabricated structure;

[0007] The prefabricated structure is subjected to a pressing process so that it is continuously subjected to external pressure to compress the bundle shape during the process, thereby obtaining a flat and optimized structure.

[0008] In some optional embodiments, the flattened and optimized structure is subjected to a secondary curing treatment so that the organic resin therein undergoes a cross-linking reaction to obtain a flattened and optimized conductive structure.

[0009] In some optional embodiments, when the volatilization amount of the volatile substance in the printed structure reaches 10% to 60%, the prefabricated structure is subjected to cold pressing to obtain the flattened optimized structure.

[0010] In some optional embodiments, when the volatilization amount of the volatile substance in the printed structure reaches 40% to 80%, the prefabricated structure is subjected to a heat pressing process to obtain the flattened optimized structure.

[0011] In some optional embodiments, the volatile substance includes at least a solvent in the conductive paste.

[0012] In some optional embodiments, the secondary curing treatment of the flattened optimized structure to cause the organic resin therein to undergo a cross-linking reaction includes:

[0013] The flattened optimized structure is provided with conditions that promote the cross-linking reaction of the organic resin therein.

[0014] In some optional embodiments, the organic resin is a photocurable resin, a thermoplastic resin or a thermosetting resin.

[0015] In some optional embodiments, the primary curing process satisfies the volatilization conditions of the volatile substance but does not satisfy the sufficient cross-linking reaction conditions of the organic resin.

[0016] Another object of the present invention is to provide a printing and flattening device for low-temperature conductive paste, so as to improve the problem of poor surface flatness of printed circuits caused by the surface tension of the conductive paste in the prior art.

[0017] In some illustrative embodiments, the printing and planarization equipment of the low-temperature conductive paste is applied to a conductive paste with an organic resin as a binder phase, comprising:

[0018] A primary curing device is used to perform a primary curing treatment on the printed structure after the printed structure is formed on the surface of the printing substrate by using the conductive paste, so that the volatile matter in the printed structure reaches a volatilization amount of 10% to 80%, thereby obtaining a prefabricated structure;

[0019] A pressing device is used to press the prefabricated structure so that it is continuously pressed by external pressure during the process to obtain a flat and optimized structure;

[0020] The secondary curing device is used to perform secondary curing treatment on the flattened and optimized structure so as to cause the organic resin therein to undergo a cross-linking reaction to obtain a flattened and optimized conductive structure.

[0021] Another object of the present invention is to provide a conductive structure that can be obtained by any one of the printing and leveling methods for low-temperature conductive paste or the printing and leveling equipment for low-temperature conductive paste.

[0022] The conductive structure comprises: a printing substrate; and a flat and optimized conductive structure attached to the surface of the printing substrate.

[0023] In some optional embodiments, the conductive structure further includes: one or more metal plating layers attached to the surface of the flattened and optimized conductive structure.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] After applying the conductive paste to form the printed structure, the present invention sequentially performs a curing treatment and a pressing treatment on the printed structure, and reduces the influence of the surface tension of the conductive paste on the surface flatness as much as possible through the pressing treatment, improves the flatness of the conductive structure, and narrows the gap with the traditional copper clad laminate; in addition, the present application controls the volatilization amount of the volatile substance in the printed structure to be between 10% and 80% in the primary curing treatment, thereby reducing the problems of adhesion with the pressing parts, extrusion overflow deformation, and extrusion breakage caused by too small or too large volatilization amount of the volatile substance in the subsequent pressing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a process example 1 of the printing and leveling method of the low-temperature conductive paste in the embodiment of the present invention;

[0027] Figure 2 is a process schematic diagram of a printing and leveling method of a low-temperature conductive paste in an embodiment of the present invention;

[0028] Figure 3 This is a second process example of a printing and leveling method of a low-temperature conductive paste in an embodiment of the present invention;

[0029] Figure 4 It is a structural example of a printing and leveling device for low-temperature conductive paste in an embodiment of the present invention;

[0030] Figure 5 is a structural example 1 of the conductive structure in the embodiment of the present invention;

[0031] Figure 6 is a second structural example of the conductive structure in the embodiment of the present invention;

[0032] Figure 7 is a thermogravimetric curve of Tg of Example 1 in the embodiments of the present invention;

[0033] Figure 8is the Keyence laser confocal measurement result 1 of Example 1 in the embodiments of the present invention;

[0034] Fig. 9 This is the Keyence laser confocal measurement result 2 of Example 1 in the embodiments of the present invention;

[0035] Fig.10 is a thermogravimetric curve of Tg of Example 2 in the embodiments of the present invention;

[0036] Fig.11 is the Keyence laser confocal measurement result 1 of Example 2 in the embodiments of the present invention;

[0037] Fig.12 This is the Keyence laser confocal measurement result 2 of Example 2 in the embodiment of the present invention;

[0038] Fig.13 is a thermogravimetric curve of Tg of Example 3 in the embodiments of the present invention;

[0039] Fig.14 This is the Keyence laser confocal measurement result of Example 3 in the embodiments of the present invention. DETAILED DESCRIPTION

[0040] The following description and the accompanying drawings fully illustrate specific embodiments of the present invention so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The examples represent possible variations only. Unless explicitly required, separate components and functions are optional, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of the present invention includes the entire scope of the claims, and all available equivalents of the claims. In this article, these embodiments of the present invention may be represented individually or collectively by the term "invention", which is merely for convenience, and if more than one invention is disclosed in fact, it is not intended to automatically limit the scope of the application to any single invention or inventive concept.

[0041] Prior to this application, the industry generally adopted the method of polishing and grinding after printing to improve the flatness of the surface of the conductive paste. However, this method is currently only applicable to conductive pastes with high-temperature conductive resins using glass powder as the bonding phase. This is mainly because such conductive pastes have excellent adhesion and structural strength after high-temperature sintering, and can be subjected to high-intensity mechanical grinding. However, the adhesion and structural strength of low-temperature conductive pastes with organic resins as the bonding phase after curing are far inferior to those of high-temperature conductive pastes. During the polishing process, the printed circuits are easily broken and fall off. Therefore, the applicant proposed the idea and verification of achieving flattening of the conductive paste after printing through conventional pressing, and proposed this application.

[0042] It should be noted that the various technical features in the embodiments of the present invention can be combined with each other without conflict.

[0043] The present invention discloses a printing and leveling method for low-temperature conductive paste. Specifically, Figure 1-2 As shown, Figure 1 This is a process example 1 of the printing and leveling method of the low-temperature conductive paste in the embodiment of the present invention; Figure 2 : is a process schematic diagram of a printing and leveling method of a low-temperature conductive paste in an embodiment of the present invention; the printing and leveling method of a low-temperature conductive paste is applied to a conductive paste with an organic resin as a bonding phase, comprising:

[0044] Step a, after forming the printed structure 2 on the surface of the printing substrate 1 by using the conductive paste, the printed structure 1 is subjected to a curing treatment so that the volatile matter therein reaches a volatilization amount of 10% to 80%, thereby obtaining a prefabricated structure 2a;

[0045] Step b: performing a pressing process on the prefabricated structure 2a so that it is continuously pressed into a bundle shape by external pressure during the process, thereby obtaining a flat and optimized structure 2b.

[0046] The conductive paste in the embodiment of the present invention mainly includes three main components: conductive particles, organic resin and solvent, and may also include one or more additives in other optional embodiments; the volatile substance in the embodiment of the present invention mainly refers to the volatile component in the printed body (conductive paste), generally including at least the solvent in the conductive paste, and may also include one or more volatile additives in other optional embodiments.

[0047] After applying the conductive paste to form the printed structure, the present invention sequentially performs a curing treatment and a pressing treatment on the printed structure, and reduces the influence of the surface tension of the conductive paste on the surface flatness as much as possible through the pressing treatment, improves the flatness of the conductive structure, and narrows the gap with the traditional copper clad laminate; in addition, the present application controls the volatilization amount of the volatile substance in the printed structure to be between 10% and 80% in the primary curing treatment, thereby reducing the problems of severe extrusion deformation, unclear extrusion shaping effect, and even extrusion breakage caused by too small or too large volatilization amount of the volatile substance in the subsequent pressing treatment.

[0048] In the embodiment of the present invention, when the volatilization amount of the volatile substance in the printed structure is controlled to be above 10%, the rheological properties of the prefabricated structure can be limited to a certain extent, avoiding serious extrusion deformation problems. When the volatilization amount of the volatile substance in the printed structure is controlled to be below 80%, the printed structure will not be too strong, avoiding the problem of unclear extrusion shaping, or even extrusion fracture and breakage during the pressing process.

[0049] Specifically, the pressing process in step b of the embodiment of the present invention can be cold pressing process or hot pressing process;

[0050] The cold pressing treatment in the embodiment of the present invention refers to controlling the cold pressing temperature below 60°C while providing external pressure; specifically, the cold pressing temperature can be controlled below 50°C, below 40°C, below 30°C, below 20°C, below 10°C, and below 0°C. At this cold pressing temperature, the flow deformation capacity of the prefabricated structure is effectively limited, and severe extrusion deformation is not likely to occur when pressure is applied.

[0051] Preferably, the cold pressing temperature used in the cold pressing treatment in the embodiment of the present invention can be in the range of 20°C to 30°C, within which the flow deformation capacity of the prefabricated structure can be well restricted. At the same time, this temperature range basically belongs to the room temperature range, thereby reducing the temperature control requirements and energy consumption of the press.

[0052] In the case of cold pressing in step b of the embodiment of the present invention, during the one-time curing process in step a, the volatilization amount of the volatile substance in the printed structure needs to be controlled within the range of 10% to 60%, which can effectively reduce the decrease in fluidity of the prefabricated structure at a lower temperature, increase in structural strength and hardening, resulting in the probability of the prefabricated structure being not obvious in shaping effect and being crushed by extrusion. Preferably, during the one-time curing process, the volatilization amount of the volatile substance in the printed structure can be controlled within the range of 20% to 40%, at which time the cold pressing effect of the prefabricated structure is the best.

[0053] The hot pressing treatment in the embodiment of the present invention refers to providing external pressure while controlling the hot pressing temperature between 100°C and 150°C; specifically, the hot pressing temperature can be controlled between 100°C and 110°C, 110°C and 120°C, 120°C and 130°C, 130°C and 140°C, and 140°C and 150°C. Preferably, the hot pressing temperature used in the hot pressing treatment in the embodiment of the present invention can be within the range of 120°C to 140°C, which can effectively improve the flow deformation ability of the prefabricated structure and reduce the solvent volatilization efficiency in the prefabricated structure, thereby avoiding the problem of premature hardening of the prefabricated structure, and the problem of the prefabricated structure having an unclear shaping effect and being crushed by extrusion.

[0054] In the embodiment of the present invention, when step b is subjected to hot pressing, during the one-time curing process in step a, the volatilization amount of the volatile substance in the printed structure needs to be controlled within the range of 40% to 80%, which can effectively control the fluidity of the prefabricated structure under high temperature and avoid the problem of severe deformation under pressure during the hot pressing process. Preferably, during the one-time curing process, the volatilization amount of the volatile substance in the printed structure can be controlled within the range of 60% to 70%, at which time the hot pressing effect of the prefabricated structure is the best.

[0055] After a long period of experimental verification, the applicant found that the fluidity of the conductive paste mainly depends on its solvent content. As the solvent gradually evaporates, the fluidity of the conductive paste will gradually decrease, and the deformation ability will become worse. When the volatile substances such as the solvent reach 60% of the volatilization amount, the remaining solvent and the organic resin can be in a relatively stable state. The organic resin can have a good binding force on the solvent. Under hot pressing treatment, the solvent can be prevented from being squeezed to drive the organic resin and conductive filler to migrate and overflow on a large scale, which greatly reduces the deformation effect of pressing on the conductive structure in the direction perpendicular to the extrusion force.

[0056] The pressing process in the embodiment of the present invention can provide a shaping pressure of 100N to 300N for the prefabricated structure to be shaped (prefabricated structure and printing substrate) as a whole; in some embodiments, the shaping pressure of the prefabricated structure to be shaped can be 8000Pa to 25000Pa.

[0057] The one-time curing treatment in step a of the embodiment of the present invention satisfies the volatilization conditions of the volatile substance, but does not satisfy the sufficient cross-linking reaction conditions of the organic resin. Specifically, the volatilization conditions of the volatile substance can be achieved by applying temperature and adjusting time, so that the volatilization amount of the volatile substance in the prefabricated structure is between 10% and 80%. The sufficient cross-linking reaction conditions of the organic resin refer to the sufficient cross-linking and curing of the organic resin after providing appropriate temperature or appropriate irradiation for a period of time, which can be obtained according to the instructions of the commercially available slurry or self-verification.

[0058] The organic resin in the conductive paste in the embodiment of the present invention can be a photocurable resin, a thermoplastic resin or a thermosetting resin. The photocurable resin requires an external curing light source such as ultraviolet light irradiation to make it undergo a cross-linking reaction; the thermosetting resin and the thermoplastic resin require an external corresponding temperature to make them undergo a cross-linking reaction.

[0059] In the case where the organic resin is a thermosetting resin, the temperature of the primary curing treatment should be higher than the boiling point of the volatile substance and lower than the cross-linking reaction temperature of the organic resin. In this embodiment, for the thermosetting resin, it is necessary to control the temperature of the primary curing treatment to be lower than the cross-linking reaction temperature of the thermosetting resin to avoid premature curing affecting the pressing effect. In other embodiments, for the photocurable resin, it is necessary to pay attention to the temperature meeting the temperature resistance temperature of each material.

[0060] The printing and leveling method of the low-temperature conductive paste in the embodiment of the present invention may further include:

[0061] Step c: performing a secondary curing treatment on the flattened and optimized structure 2b to cause the organic resin therein to undergo a cross-linking reaction, thereby obtaining a flattened and optimized conductive structure 2c.

[0062] The secondary curing treatment in step c of the embodiment of the present invention mainly refers to providing conditions for the flattened optimized structure (conductive paste) to promote the cross-linking reaction of the organic resin therein. The conditions are mainly selected and parameterized according to the curing type of the organic resin, including but not limited to one or more of temperature, time, and light source.

[0063] The present invention also discloses a printing and leveling method for low-temperature conductive paste. Specifically, Figure 3 As shown, Figure 3 This is a second process example of a printing and leveling method for a low-temperature conductive paste in an embodiment of the present invention; the printing and leveling method for a low-temperature conductive paste is applied to a conductive paste using an organic resin as a bonding phase, and includes:

[0064] Step S11, providing a printing substrate;

[0065] Step S12, forming a printed structure on the printing substrate using a conductive paste;

[0066] Step S13, performing a curing treatment on the printed body to control the volatilization amount of the volatile substances in the printed body to be 10% to 80%, thereby obtaining a prefabricated structure;

[0067] Step S14, pressing the prefabricated structure so that it is continuously pressed by external pressure to obtain a flat and optimized structure;

[0068] Step S15, performing secondary curing treatment on the flattened and optimized structure to cause the organic resin therein to undergo a cross-linking reaction until the curing is completed, thereby obtaining a flattened and optimized conductive structure.

[0069] The present invention discloses a printing and leveling device for low-temperature conductive paste, specifically, Figure 4 As shown, Figure 4 This is a structural example of a printing and leveling device for low-temperature conductive paste in an embodiment of the present invention; the printing and leveling device for low-temperature conductive paste is applied to a conductive paste with an organic resin as a bonding phase, and includes:

[0070] The primary curing device 10 is used to perform a primary curing treatment on the printed body, so that the volatilization amount of the volatile substances in the printed body is controlled to be 10% to 80%, thereby obtaining a prefabricated structure;

[0071] The pressing device 20 is used to press the prefabricated structure so that it is continuously pressed into a bundle shape by external pressure during the process to obtain a flat and optimized structure.

[0072] In some embodiments, the printing and leveling equipment of the low-temperature conductive paste in the embodiments of the present invention may further include:

[0073] The secondary curing device 30 is used to perform secondary curing treatment on the flattened and optimized structure to cause the organic resin therein to undergo a cross-linking reaction to obtain a flattened and optimized conductive structure.

[0074] Furthermore, the primary curing device 10 in the printing flattening equipment can adopt a thermal drying device (such as a hot oven, a constant temperature box, a hot oven, a constant temperature oven), and the pressing device 20 can adopt a pressing machine, a cold press or a hot press, including an upper pressing plate and a lower pressing plate; the secondary curing device 30 can adopt a thermal drying device (such as a hot oven, a constant temperature box, a hot oven, a constant temperature oven) or a light curing device (such as an ultraviolet light curing device).

[0075] In some embodiments, the printing and planarization equipment may further include: a printing device for forming a printed structure on a printing substrate using a conductive paste.

[0076] Furthermore, a conveyor belt 40 is provided between the primary curing device 10, the pressing device 20, and the secondary curing device 30 in the printing and leveling equipment, so that a production line is formed between the devices; in other embodiments, a printing device can also be added to the production line.

[0077] The embodiment of the present invention discloses a conductive structure, such as Figure 5-6 As shown, the conductive structure can be obtained by any one of the printing and leveling methods for low-temperature conductive paste or the printing and leveling equipment for low-temperature conductive paste.

[0078] Furthermore, the conductive structure may also include: one or more metal plating layers 3 (e.g., a three-layer gold-plated structure of copper 31, nickel 32, and gold 33) attached to the surface of the flattened and optimized conductive structure 2c. The metal plating layer may be one or more of copper, nickel, gold, silver, zinc, and tin. Compared with directly performing gold plating on an untreated conductive structure (with poor flatness), the flatness of the metal plating layer can be improved, thereby meeting the requirements of the prior art.

[0079] The printing substrate in the embodiment of the present invention can be a soft or hard substrate, preferably a sheet or film material, etc.; wherein, the hard substrate can be selected from traditional PCB boards, such as glass fiber boards, semi-glass fiber boards, such as FR-4, CEM-1, 22F, CEM-3, etc. In addition to traditional PCB boards, wood, glass, plastic, PMMA (Acrylic) and the like can also be used; and the soft substrate can include flexible stretchable substrates and flexible non-stretchable substrates, such as PET, PVC, PU, ​​PC, PP, PA, PI, CPI (transparent PI), TPE, etc. In addition to the above substrates, PDMS, silica gel, fabrics (such as non-woven fabrics, nylon, washed cotton, polyester, spandex and woven fabrics blended with various materials, etc.), adhesive films (not limited to TPU, TPV), etc. can also be selected. Those skilled in the art should understand that in addition to the above substrates, the substrate in the embodiment of the present invention can also be selected from other substrates in the prior art that can meet the requirements of forming a conductive structure thereon.

[0080] The application process of the printed body in the embodiment of the present invention can be formed by printing, printing and other methods, including but not limited to spraying, extrusion, spin coating, silk screen printing, pad printing, gravure printing, electric field spraying, coating, air flow spraying and other processes; the metal plating in the embodiment of the present invention can be formed by electroplating or chemical plating and other methods.

[0081] Example 1

[0082] In this embodiment, a thermoplastic low-temperature conductive paste composed of silver powder, organic resin, solvent and additive is selected; wherein the mass percentage of the solvent in the conductive paste is 18%;

[0083] Figure 7 The Tg thermogravimetric curve of the thermosetting low-temperature conductive paste after 130°C, 5 minutes of heat treatment; primary curing treatment parameters: temperature 130°C, 5 minutes, the overall mass is reduced by 1% after treatment, so the mass volatilization ratio is 1 / 18 = 5.6%; pressing treatment parameters (hot pressing): 140°C, 2 minutes, 150N (printing substrate 0.012 square meters), Figure 8 The effect diagram after horizontal pressing is shown, and it can be seen that the degree of deformation after pressing is large and the edges are obviously crushed. Fig. 9 The topography after vertical pressing is shown. The shaping effect can be found in the peak topography, and the average height difference reaches 4.397um.

[0084] Example 2

[0085] The same conductive paste as in Example 1 was used. Fig.10 The Tg thermogravimetric curve of the thermosetting low-temperature conductive paste after 130°C, 45 minutes of heat treatment; the primary curing treatment parameters: temperature 130°C, 45 minutes, the overall mass is reduced by 15% after treatment, so the mass volatilization ratio is 15 / 18=83.3%; the pressing treatment parameters (hot pressing): 140°C, 2 minutes, 150N (printing substrate 0.012 square meters), Fig.11 The effect diagram after horizontal pressing is shown, and it can be seen that the degree of deformation after pressing is small. Fig.12 The figure shows the morphology after vertical pressing. The average height difference reaches 7.766um, the peak morphology is almost unchanged, and the pressing and shaping has almost no effect.

[0086] Example 3

[0087] The same conductive paste as in Example 1 was used. Fig.13 The Tg thermogravimetric curve of the thermosetting low-temperature conductive paste after 130°C, 20 minutes of heat treatment; primary curing treatment parameters: temperature 130°C, 20 minutes, the overall mass is reduced by 8% after treatment, so the mass volatilization ratio is 8 / 18=44.4%; pressing treatment parameters (hot pressing): 140°C, 2 minutes, 150N (printing substrate 0.012 square meters), Fig.14 The effect diagram after horizontal pressing is shown, and the degree of deformation after pressing is small. Fig.12 The morphology diagram after vertical pressing is shown. The peak morphology has been significantly improved, and the average height difference reaches 5.893um. Compared with Example 1 and Example 2, the overall shaping effect in the horizontal and vertical directions is the best.

[0088] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

Claims

1. A method for printing and flattening a low-temperature conductive paste, characterized in that, it is applied to a conductive paste with an organic resin as the binder phase, and the conductive paste contains conductive particles, including: After forming a printed structure on the surface of the substrate to be printed with the conductive paste, performing a primary curing treatment on the printed structure to make the volatile substances in it reach a volatile amount of 10% - 80%, obtaining a prefabricated structure; wherein, the primary curing treatment meets the volatilization conditions of the volatile substances and does not meet the sufficient cross-linking reaction conditions of the organic resin; Performing a pressing treatment on the prefabricated structure with a shaping pressure of 100 - 300 N or 8000 - 25000 Pa, so that it is continuously subjected to external pressure extrusion and shaping during the process, obtaining a flattened and optimized structure.

2. The method for printing and flattening a low-temperature conductive paste according to claim 1, characterized in that, When the volatile substances in the printed structure reach a volatile amount of 10% - 60%, performing a cold pressing treatment on the prefabricated structure to obtain the flattened and optimized structure.

3. The method for printing and flattening a low-temperature conductive paste according to claim 1, characterized in that, When the volatile substances in the printed structure reach a volatile amount of 40% - 80%, performing a hot pressing treatment on the prefabricated structure to obtain the flattened and optimized structure.

4. The method for printing and flattening a low-temperature conductive paste according to claim 1, characterized in that, The volatile substances at least include the solvent in the conductive paste.

5. The method for printing and flattening a low-temperature conductive paste according to claim 1, characterized in that, It further includes: Performing a secondary curing treatment on the flattened and optimized structure to make the organic resin in it undergo a cross-linking reaction, obtaining a flattened and optimized conductive structure.

6. The method for printing and flattening a low-temperature conductive paste according to claim 1, characterized in that, The organic resin is a photo-curable resin, a thermoplastic resin or a thermosetting resin.

7. A printing and flattening device for a low-temperature conductive paste, characterized in that, it is applied to a conductive paste with an organic resin as the binder phase, including: A primary curing device for performing a primary curing treatment on the printed structure after forming a printed structure on the surface of the substrate to be printed with the conductive paste, so that the volatile substances in it reach a volatile amount of 10% - 80%, obtaining a prefabricated structure; wherein, the primary curing treatment meets the volatilization conditions of the volatile substances and does not meet the sufficient cross-linking reaction conditions of the organic resin; A pressing device for performing a pressing treatment on the prefabricated structure, so that it is continuously subjected to external pressure extrusion and shaping during the process, obtaining a flattened and optimized structure.

8. The printing and flattening device for a low-temperature conductive paste according to claim 7, characterized in that, It further includes: A secondary curing device for performing a secondary curing treatment on the flattened and optimized structure to make the organic resin in it undergo a cross-linking reaction, obtaining a flattened and optimized conductive structure.

9. A conductive structure, characterized in that, It is obtained by the method for printing and flattening a low-temperature conductive paste according to any one of claims 1 - 6 or the printing and flattening device for a low-temperature conductive paste according to any one of claims 7 - 8.

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