A transfer substrate and a transfer method

Abstract

This invention discloses a transfer substrate and a transfer method. The transfer substrate has one or more grooves arranged in a pattern and configured to fill with printing paste. When irradiated by a laser beam, the printing paste is released from the grooves onto a receiving substrate. This invention achieves this by providing a release layer within the grooves of the transfer substrate. This release layer at least partially vaporizes upon laser beam irradiation, generating a localized pressure higher than standard atmospheric pressure in the space between the printing paste and the grooves; and / or by at least partially vaporizing the printing paste upon laser beam irradiation, generating a localized pressure higher than standard atmospheric pressure in the space between the printing paste and the grooves. This localized high pressure can constitute the driving force for activating the release and filling of the printing paste, contributing to obtaining printed grid lines with a higher aspect ratio.

Description

TECHNICAL FIELD

[0001] The present application relates to a transfer substrate, in particular a laser transfer substrate, and belongs to the technical field of transfer printing. BACKGROUND

[0002] In the prior art, the electrode printing of a solar cell is generally performed by screen printing. The printing paste on the screen is pressed by a squeegee to transfer the printing paste to the cell to complete the printing of the electrode grid lines. The shape and height-width ratio of the grid lines are determined by the squeegee pressure, squeegee speed and screen structure.

[0003] The laser transfer process is a non-contact printing scheme. It has a good development prospect because it can print high-height-width-ratio printing grid lines.

[0004] In the laser transfer process, the laser transfer substrate (also referred to as a source substrate) has a groove pattern on one side to fill the printing paste. During use, the printing paste in the groove pattern is separated from the groove and transferred to the receiving substrate arranged below by irradiating the opposite side of the groove pattern with a laser. There are two types of transfer substrates, one is a flexible substrate (such as a high polymer substrate), and the other is a hard substrate (such as a glass substrate).

[0005] The existing transfer substrate has the following problems: 1. The squeegee is used to scrape the printing paste into the groove pattern, and the laser is damaged by long-term laser transfer. The groove is prone to edge collapse, which affects the service life of the transfer substrate; 2. The shape of the groove is not reasonable. During laser transfer, the paste is difficult to be completely released from the groove and transferred to the receiving substrate. The residual paste adheres to the transfer substrate or even reacts with the transfer substrate, resulting in incomplete release during transfer, less paste filling later, and affecting the transfer effect.

[0006] Moreover, higher height-width-ratio and printing quality, and lower transfer energy are still the goals to be pursued. SUMMARY

[0007] The present application aims to at least partially solve one of the above technical problems.

[0008] In one aspect, the present application provides a transfer substrate, comprising a single or multiple grooves arranged on the transfer substrate, the grooves being arranged in a pattern and configured to be able to fill the printing paste, the printing paste being released from the grooves to a receiving substrate when irradiated by a laser beam, wherein a release layer is arranged in the groove, the release layer being at least partially gasified when irradiated by the laser beam, and a local space pressure higher than the standard atmospheric pressure is generated in the gap space between the printing paste and the groove.

[0009] and / or the printing paste at least partially vaporizes upon laser beam irradiation, creating a local spatial pressure higher than the standard atmospheric pressure in the gap space between the printing paste and the trench.

[0010] Further, a transfer substrate according to the present application, wherein the local spatial pressure is greater than 1.05 times the standard atmospheric pressure, or,

[0011] the local spatial pressure is greater than 1.1 times the standard atmospheric pressure, or,

[0012] the local spatial pressure is greater than 1.2 times the standard atmospheric pressure.

[0013] Further, a transfer substrate according to the present application, wherein the release layer contains a release component that at least partially vaporizes upon laser beam irradiation, and / or,

[0014] the printing paste contains a release component that at least partially vaporizes upon laser beam irradiation.

[0015] Further, a transfer substrate according to the present application, wherein the laser beam irradiation is near-infrared irradiation, the release component is a near-infrared absorbing dye, and the release component decomposes and vaporizes upon laser beam irradiation.

[0016] Further, a transfer substrate according to the present application, wherein the near-infrared absorbing dye comprises at least one of a diimmonium ion complex, a dithioene complex, a phthalocyanine, a derivative or a salt thereof, and / or a combination thereof.

[0017] Further, a transfer substrate according to the present application, wherein the release layer comprises at least a release component and a solvent.

[0018] Further, a transfer substrate according to the present application, wherein the transfer substrate is a rigid substrate, a flexible substrate, a substrate having a rigid layer and a flexible layer, or a substrate having a rigid layer and a flexible film.

[0019] Further, a transfer substrate according to the present application, wherein the trench has a roughness with Sa of 0.02 μm to 2 μm and Sz of less than 4 μm.

[0020] Further, a transfer substrate according to the present application, wherein the trench has a roughness with Sa of 0.2 μm to 0.8 μm and Sz of less than 1.6 μm.

[0021] Further, a transfer substrate according to the present application, further comprising an antireflection film coating disposed on a surface of the transfer substrate opposite the trench.

[0022] In another aspect, the present application provides a transfer method, wherein, filling a printing paste in a trench of a transfer substrate, releasing the printing paste from the trench to a receiving substrate by laser beam irradiation, wherein the printing paste at least partially gasifies at the laser beam irradiation, a local space pressure higher than a standard atmospheric pressure is generated in a gap space between the printing paste and the trench;

[0023] Or, coating a release layer inside the trench of the transfer substrate, filling a printing paste in the trench, releasing the printing paste from the trench to a receiving substrate by laser beam irradiation, wherein the release layer and / or the printing paste at least partially gasifies at the laser beam irradiation, a local space pressure higher than a standard atmospheric pressure is generated in a gap space between the printing paste and the trench.

[0024] Further, a transfer method of the present application, wherein the local space pressure is greater than 1.05 standard atmospheric pressures, or,

[0025] The local space pressure is greater than 1.1 standard atmospheric pressures, or,

[0026] The local space pressure is greater than 1.2 standard atmospheric pressures.

[0027] Further, a transfer method of the present application, wherein the release layer contains a release component, the release component at least partially gasifies at the laser beam irradiation, and / or,

[0028] The printing paste contains a release component, the release component at least partially gasifies at the laser beam irradiation.

[0029] Further, the present application, wherein the laser beam irradiation is near-infrared irradiation, the release component is a near-infrared absorbing dye, and the release component is decomposed and gasified at the laser beam irradiation.

[0030] Further, a transfer method of the present application, wherein the near-infrared absorbing dye includes at least one of the following: a diimmonium ion complex, a dithioene complex, a phthalocyanine, a derivative or a salt thereof, and / or a combination.

[0031] Further, a transfer method of the present application, wherein the release layer is coated inside the trench of the transfer substrate by scribing.

[0032] The beneficial effects of the embodiments of the present application are described as follows.

[0033] The transfer substrate or the transfer method of the present application can form a high-pressure air gap layer between the printing paste and the groove of the transfer substrate by setting a release layer inside the groove and / or adding a release component to the printing paste, which can form a driving force to activate the release of the printing paste filled in the groove and help to obtain a printing grid line with a higher aspect ratio.

[0034] The present application can achieve good adhesion and release of the printing paste or the release layer by designing the roughness of the groove. If the roughness is too large, the inner wall and the bottom of the groove have a strong adhesion to the release layer or the layer, which makes it difficult to release the printing paste from the groove during laser transfer. If the roughness is too small, the adhesion is small and the printing paste or the release layer is easily scraped and taken away, which can cause a large number of pattern material missing in the printing paste layer formed in the groove and result in a decline in the quality of the transfer printing.

[0035] The transfer substrate of the present application is provided with a laser antireflection film on the side opposite to the groove to increase the light transmittance of the laser. The light transmittance of the transfer substrate is increased and the light absorption is reduced, which can further enhance the release effect of the printing paste and prolong the service life of the transfer substrate.

[0036] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a schematic diagram of laser transfer of the present application;

[0038] Figure 2 is a schematic diagram of the structure of a transfer substrate according to an embodiment of the present application;

[0039] Figure 3 is a schematic diagram of the structure of a transfer substrate according to an embodiment of the present application.

[0040] The drawings include a transfer substrate 1, a release layer 2, a printing paste 3, a laser device 4, a receiving substrate 5, a stage 6, and a groove 11. DETAILED DESCRIPTION

[0041] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0042] The present application will be further described in detail below in combination with specific embodiments, which cannot be understood as limiting the scope of the claimed present application.

[0043] Reference Figure 1As shown in Fig. 1, a laser transfer printing method is provided. The laser transfer printing method comprises the following steps: providing a transfer substrate 1, the transfer substrate 1 comprising a plurality of grooves 11, each groove 11 having a groove bottom 12 and a groove wall 13, the groove wall 13 being substantially vertical, and the groove wall 13 having a roughness Ra, the roughness Ra being in the range of 0.1-10 microns; providing a printing paste 3; filling the grooves 11 of the transfer substrate 1 with the printing paste 3; placing the transfer substrate 1 upside down on a receiving substrate 5, the receiving substrate 5 being fixed on a stage 6, the stage 6 being spaced apart from the transfer substrate 1; and irradiating the grooves 11 of the transfer substrate 1 with a laser beam 4, the laser beam 4 being emitted from a laser device 4, the laser device 4 being located on the other side of the transfer substrate 1, the printing paste 3 being transferred from the grooves 11 to the receiving substrate 5, and the electrode printing of the receiving substrate 5 being completed.

[0044] The applicant has found in the research that the material, groove shape, roughness, etc. of the transfer substrate directly affect the laser transfer printing effect, and if a local high pressure can be generated between the groove and the printing paste during transfer, a pushing force can be provided to the printing paste, so that the printing paste is more easily transferred to the receiving substrate. The present application aims to provide a transfer substrate capable of realizing efficient laser transfer printing, a transfer substrate with high aspect ratio, and a transfer substrate with good transfer quality. The present application also provides a transfer method capable of realizing efficient laser transfer printing, generating high aspect ratio, and good transfer quality.

[0045] The transfer substrate and the transfer method of the present application are suitable for transfer printing technology, especially for contactless printing of electrode grid lines in the processing of solar cells using laser transfer printing technology.

[0046] Of course, the transfer substrate, the transfer paste and the transfer method of the present application are also suitable for electrode printing other than solar cell processing, such as generating conductive lines or pads or other features on laminates used for PCB or other printed circuit boards. Other applications can include generating conductive features in the manufacturing process of mobile phone antennas, decorative and functional automotive glass, semiconductor integrated circuits (IC), semiconductor IC package connections, printed circuit boards (PCB), PCB component assembly, optical biological, chemical and environmental sensors and detectors, radio frequency identification (RFID) antennas, organic light emitting diode (OLED) displays (passive or active matrix), OLED illumination sheets, printed batteries and other applications.

[0047] The transfer substrate 1 of the present application is a rigid substrate, a flexible substrate, or a transfer substrate comprising at least one rigid layer.

[0048] More specifically, the transfer substrate 1 can be a rigid substrate. The transfer substrate 1 can also be a double-layer substrate with a rigid layer and a flexible layer, or a substrate with a rigid layer and a flexible film. Of course, the transfer substrate 1 can also be a single-layer flexible substrate or a multi-layer flexible substrate.

[0049] As a non-limiting embodiment, the transfer substrate 1 is a rigid substrate made of a rigid material, which includes one or more grooves 11 disposed on the transfer substrate 1. The grooves 11 are arranged in a pattern and configured to be able to fill the printing paste 3 and to release the printing paste 3 from the grooves 11 onto the receiving substrate 5 when irradiated by a laser beam.

[0050] As a non-limiting embodiment, the transfer substrate 1 is a double-layer substrate having a rigid layer and a flexible layer. The rigid layer is made of a rigid material and provides support. The flexible layer is disposed on the rigid layer and is made of a flexible material. One or more grooves 11 are provided on the flexible layer. The grooves 11 are arranged in a pattern and configured to be able to fill the printing paste 3 and, when irradiated by a laser beam, release the printing paste 3 from the grooves 11 onto the receiving substrate 5.

[0051] As a non-limiting embodiment, the transfer substrate 1 is a substrate of a rigid material with a flexible film, which includes one or more grooves 11 disposed on the transfer substrate 1. The grooves 11 are arranged in a pattern and configured to be able to fill the printing paste 3 and release the printing paste 3 from the grooves 11 onto the receiving substrate 5 when irradiated by a laser beam. A flexible film is disposed on the side with the grooves 11, and the flexible film is made of a flexible material.

[0052] As a non-limiting embodiment, the transfer substrate 1 is a substrate of a single or double layer of flexible material, which includes one or more grooves 11 disposed on the transfer substrate 1. The grooves 11 are arranged in a pattern and configured to be able to fill the printing paste 3 and to release the printing paste 3 from the grooves 11 onto the receiving substrate 5 when irradiated by a laser beam.

[0053] The rigid material described in this application is a rigid material that is transparent to lasers. Options include glass-based transparent panels and polymer-based transparent panels, with a preference for high laser transmittance materials (transmitting wavelengths in the range of 532nm-1064nm). Specifically, preferred materials include quartz glass, ordinary glass, rigid plastic sheets, and high-polymerization polymer substrates, which provide rigidity and good support. As a non-limiting embodiment, with a laser wavelength of 1064nm, quartz glass is chosen as the rigid material. The flexible material described is also transparent to lasers, preferably an organic material with high laser transmittance, and more preferably, a partially crystalline or amorphous polymer layer.

[0054] In some embodiments, the organic material of the flexible layer can be a partially crystalline or amorphous polymer, specifically, one of polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, fully aromatic polyester, aliphatic-aromatic copolyester, copolyacrylate, polycarbonate, polyamide, polysulfone, polyethersulfone, polyetherketone, polyamide-imide, polyether-imide, aromatic polyimide, alicyclic polyimide, fluorinated polyimide, cellulose acetate, cellulose nitrate, aromatic polyamide, polyvinyl chloride, polyphenol, polyarylate, polyphenylene sulfide, polyphenylene ether, and polystyrene.

[0055] Flexible films and flexible layers are made of the same material and have similar functions. However, their manufacturing methods can differ. For example, a flexible layer is applied to a rigid layer using methods such as mounting or coating, and it is relatively thick. A flexible film, on the other hand, is applied to a rigid layer using methods such as scraping or coating, and it is relatively thin. It may only exist within the grooves, and not between the grooves. If either the flexible layer or the flexible film is damaged after long-term use, it can be removed and remade.

[0056] The transfer substrate 1 of this application preferably has a rigid substrate or rigid layer with a thickness of 1-10 mm to provide good support. The flexible substrate or flexible layer has a thickness of 50 μm-200 μm, and the flexible film has a thickness of 0.1 μm-5 μm. Excessive thickness of the flexible layer will severely reduce the absorption of laser energy. The flexible layer or flexible film can extend the service life of the transfer substrate. The trench 11 has a specific range in depth and width, preferably a depth of 10 μm-40 μm and a width of 10 μm-1000 μm. Different combinations of depth and width can enable the printing of the main and sub-gate electrodes of the solar cell.

[0057] As a non-limiting embodiment, the depth-to-width ratio (depth-to-width ratio) of the trench 11 is 1:1-1:04, which allows it to hold the paste at a greater depth, enabling the transfer of high aspect ratio printed grid lines during the transfer of sub-grids. Currently, the width of screen-printed sub-grid lines is 30-35 μm (after sintering), or even wider to 40-50 μm (after sintering), with a grid line height <15 μm (after sintering). While laser transfer involves a smaller distance between the solar cell and the transfer substrate, the paste still widens somewhat after transfer. Given the current optimal grid line aspect ratio design, the preferred trench 11 of the transfer substrate 1 has a depth of 15 μm-30 μm and a width of 10 μm-30 μm, suitable for sub-grid transfer. A trench depth of 10 μm-30 μm and a width of 60 μm-200 μm is suitable for main grid transfer.

[0058] In the transfer substrate 1 of this application, the cross-sectional shape of the groove 11 is a shape in which the width of the groove opening is greater than or equal to the width of the bottom, more preferably a rectangle, triangle, U-shape, or trapezoid. It should be noted that the aforementioned depth-to-width ratio is the ratio of the groove depth to the width of the groove opening.

[0059] The transfer substrate 1 of this application has a trapezoidal cross-sectional shape for the trench 1, with the angle of inclination of the hypotenuse being 60-90°, preferably 75-90°. The resulting grid lines after transfer have both a good aspect ratio and are less prone to surface collapse.

[0060] However, during the transfer process, the gas driving force generated after absorbing laser energy tends towards the receiving substrate. After transfer, the grid lines will experience a certain morphological collapse, with reduced height and increased width. This requires a printing paste with higher viscosity, and the desorption force during transfer also needs to be greater. Therefore, in this application, the desorption ability is enhanced by adding a release layer in the trench and / or adding organic release components to the printing paste. In particular, since the printing paste is filled in a U-shaped trench, after absorbing laser energy, the organic release components decompose / vaporize in the small space between the printing paste and the trench. Gas pressure is formed in the narrow spaces on the bottom and sides of the trench, squeezing the printing paste. The paste desorbs and is driven away from the trench by the gas to reach the receiving substrate. Under the action of high release gas pressure, the paste 3 needs to have good shape retention ability after reaching the receiving substrate. That is, the paste 3 needs to have sufficient adhesive force to maintain the contour shape during the transfer process to prevent / reduce the physical expansion tendency of the paste during the transfer process. In this application, the ability to maintain shape is achieved by increasing the composition of the metallic conductive component and the inorganic binder in the printing paste 3. The total weight of the metallic conductive component and the inorganic binder accounts for 88-95 wt% of the paste 3, wherein the metallic conductive component accounts for no less than 85 wt% of the total weight of the paste 3, and the total weight of the inorganic binder accounts for 3-10 wt%, preferably 5-8 wt%, thus balancing the bonding ability of the metallic conductive component and the sintering penetration ability of the dielectric layer.

[0061] Specifically, as a preferred embodiment, to further improve the transfer quality, the transfer substrate 1 of this application has a release layer 2 disposed inside its grooves. When irradiated by a laser beam, the release layer 2 at least partially vaporizes, generating a local pressure higher than standard atmospheric pressure in the local space between the printing paste 3 and the groove 11.

[0062] Specifically, due to the absorption of the laser beam, when the release layer 2 is at least partially vaporized, an air gap layer with a pressure of at least 1.05 times the standard atmospheric pressure is formed in the local space. This air gap layer maintains a pressure difference of at least 0.05 times the standard atmospheric pressure with the external atmospheric pressure of the transfer paste layer 3. In this way, the transfer process can be achieved without increasing the laser power. Moreover, experiments have shown that it is possible to transfer printing pastes with higher aspect ratios and achieve better transfer results.

[0063] As a non-limiting embodiment, the release layer 2 includes at least a release component. As a non-limiting embodiment, the laser beam is a near-infrared laser beam (e.g., 1064 nm), and the release component is a near-infrared (NIR) absorbing dye. The NIR absorbing dye decomposes at least partially under laser irradiation, and during decomposition, an air gap layer pressure of at least 1.05 times the standard atmospheric pressure is formed in the local space.

[0064] Furthermore, in one transfer substrate of this application, the NIR absorbing dye includes at least one of the following: diimide ion complex, dithioene complex, phthalocyanine, its derivatives or salts and / or combinations thereof.

[0065] Furthermore, the release layer 2 contains the aforementioned release components, as well as solvents and additives such as surfactants and / or binders. Adjusting the release components and the solvent and binder components in the release layer allows for the formation of a greater internal air gap pressure when the release layer decomposes at least partially. (Generally, increasing the release components can create a greater internal air gap pressure) without requiring increased laser power to vaporize the organic components in the transfer paste layer to increase the air gap pressure.

[0066] Specifically, in this application, the solvent can be acetone, ethylene glycol ether, or other solvents. The binder can be a polymer and / or a polymer precursor, such as polyvinyl butyral. It should be understood that the amount of gas produced after decomposition upon absorbing laser energy varies greatly depending on the specific materials in the NIR absorbing dye or solvent; generally speaking, the higher the carbon content in the material, the more gaseous components can be produced per unit weight of material decomposition / gasification; however, the specific gaseous components produced per unit weight of material decomposition / gasification are also limited by the oxygen content, which will not be further restricted or explained here.

[0067] Furthermore, by adjusting the content of the release component in the release layer 1 according to the resistance that the printing paste layer needs to overcome when it leaves the trench, a local spatial pressure higher than 1.1 standard atmospheres can be generated in the small space between the printing paste and the trench, thereby effectively releasing the printing paste from the trench onto the receiving substrate.

[0068] Furthermore, by adjusting the content of the release component in the release layer 1 according to the resistance that the printing paste layer needs to overcome when it leaves the trench, a local spatial pressure higher than 1.2 standard atmospheres can be generated in the small space between the printing paste and the trench, thereby effectively releasing the printing paste from the trench onto the receiving substrate.

[0069] Furthermore, the aforementioned releasing components can also be incorporated into the printing paste 3.

[0070] Specifically, the transfer substrate 1 of this application includes one or more grooves 11 disposed on the transfer substrate 1. The grooves 11 are arranged in a pattern and configured to be able to fill the printing paste 3 and to release the printing paste 3 from the grooves 11 onto the receiving substrate 5 when irradiated by a laser beam. The printing paste 3 is at least partially decomposed when irradiated by the laser beam, and a local spatial pressure higher than the standard atmospheric pressure is generated in the gap space between the printing paste 3 and the grooves 11.

[0071] Thanks to the aforementioned release components in the printing paste, when irradiated by the laser beam, the release components in the printing paste 3 are at least partially decomposed, which can generate a local spatial pressure higher than 1.05 standard atmospheres in the small space between the printing paste 3 and the groove 11. The local high pressure can constitute the driving force to activate the release filling of the printing paste 3.

[0072] Based on the resistance that the printing paste 3 needs to overcome when it leaves the groove 11, the printing paste 3 containing the release component can generate a local space pressure higher than 1.1 standard atmospheres in the small space between the printing paste and the groove, thereby effectively releasing the printing paste from the groove onto the receiving substrate.

[0073] Based on the resistance that the printing paste 3 needs to overcome when it leaves the groove 11, the printing paste 3 containing the release component can generate a local space pressure higher than 1.1 standard atmospheres in the small space between the printing paste and the groove, thereby effectively releasing the printing paste from the groove onto the receiving substrate.

[0074] Specifically, the printing paste contains organic components and solid phase components of metals such as silver, copper, tin, or bismuth that act as conductive media. By adjusting the content of the release components in the printing paste and / or the proportion of the solid phase components of the conductive metal media, based on the resistance the printing paste needs to overcome when detaching from the trench, a local spatial pressure higher than 1.1 atmospheres can be generated in the small space between the printing paste and the trench, effectively releasing the printing paste from the trench onto the receiving substrate. In particular, for printing paste layers with high viscosity and high damping properties when in contact with the inner wall of the trench, a high content of solid phase components or strong adhesive properties of organic components increases the resistance the printing paste layer needs to overcome when detaching from the trench, requiring a local spatial pressure higher than 1.2 atmospheres to be generated in the small space between the printing paste and the trench. (Generally, increasing the content of the release components in the printing paste helps to generate higher local pressure).

[0075] Furthermore, in the transfer substrate 1 of this application, more preferably, the roughness of the trench wall of its groove 11 is 2μm > Sa > 0.02μm, Sz < 4μm (Sa is the arithmetic mean height, Sz is the maximum height difference). More preferably, it is 1.5μm > Sa > 0.05μm, Sz < 3μm, and within the range of 0.8μm > Sa > 0.2μm, Sz < 1.6μm, it has better performance.

[0076] Furthermore, in this application, the transfer substrate 1 is more preferably provided with a laser antireflection coating on one side opposite to the trench 13 to increase the light transmittance of the laser. Preferably, the laser antireflection coating is a nanofilm, which reduces light absorption on the substrate, further enhancing the paste release effect and extending the service life of the transfer substrate.

[0077] More preferably, the antireflective coating is configured as a 1 / 4 wavelength stack, which is composed of two or more optical film layers with different refractive indices stacked together, and the optical path of the laser in the 1 / 4 wavelength stack is an integer multiple of 1 / 4 wavelength.

[0078] The antireflective coating can also be a nanoparticle coating, preferably a metal particle such as silver particles that can generate resonant oscillators with the laser, with a particle size between tens and hundreds of nanometers. The laser beam and the nanoparticles distributed on the surface of the nanoparticle coating form oscillators, reducing light reflection and increasing the proportion of transmitted light.

[0079] The transfer substrate of this application, through its roughness design, can achieve good adhesion and release of printing paste or release layer. When the roughness is too large, the inner wall and bottom of the groove have strong adhesion to the release layer, making it difficult to release from the groove during laser transfer. When the roughness is too small, the adhesion force is too weak, making adhesion difficult, and the printing paste or release layer is easily carried away when scraped into the groove. The paste layer formed in the groove will have more missing pattern material, resulting in a decline in transfer printing quality.

[0080] Furthermore, this application also provides a transfer method, comprising filling a groove in a transfer substrate with printing paste, and irradiating the printing paste with a laser beam to release the printing paste from the groove onto a receiving substrate, wherein the printing paste is at least partially vaporized when irradiated by the laser beam, and a local spatial pressure higher than standard atmospheric pressure is generated in the gap space between the printing paste and the groove.

[0081] Its printing paste contains the aforementioned release components. The printing paste is described above and will not be repeated here.

[0082] Furthermore, the local space pressure is higher than 1.05 standard atmospheres, higher than 1.1 standard atmospheres, or higher than 1.2 standard atmospheres.

[0083] Furthermore, this application also provides a transfer method, comprising coating a release layer inside one or more trenches of a transfer substrate, filling the trenches with printing paste, and releasing the printing paste from the trenches onto a receiving substrate by irradiation with a laser beam, wherein the release layer and / or the printing paste are at least partially vaporized when irradiated by the laser beam, and generating a local spatial pressure higher than standard atmospheric pressure in the gap space between the printing paste and the trenches.

[0084] The release layer is the same as the release layer mentioned above, and will not be repeated here.

[0085] Furthermore, the local space pressure is higher than 1.05 standard atmospheres, higher than 1.1 standard atmospheres, or higher than 1.2 standard atmospheres.

[0086] The release layer is applied to the trenches of the transfer substrate, which can be done by methods such as squeegee application or deposition.

[0087] It should be noted that both the transfer substrate of this application and the transfer method may contain release components in the release layer and the printing paste, and the effect can be enhanced when release components are present.

[0088] Through experiments, the applicant discovered that using a release layer and / or release printing paste can achieve higher aspect ratios in printed grid lines, and also improve grid line transfer quality. In some specific embodiments, the aspect ratio of the printed grid lines can be increased from around 0.5 to above 0.7, or even to 1 to 2. Simultaneously, the morphology of the printed grid lines is also improved.

[0089] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0090] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0091] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0092] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A transfer substrate, comprising: One or more grooves are disposed on a transfer substrate, the grooves are arranged in a pattern and configured to be filled with printing paste containing organic release components, the printing paste being at least partially vaporized when irradiated by a laser beam, and a local spatial pressure is generated in the gap space between the printing paste and the grooves, the local spatial pressure being greater than 1.05 standard atmospheres. The roughness of the groove is Sa = 0.02μm-2μm and Sz = less than 4μm.

2. The transfer substrate according to claim 1, characterized in that: The laser beam irradiation is near-infrared irradiation, and the organic release component is a near-infrared absorbing dye. The organic release component decomposes and vaporizes during laser beam irradiation.

3. A transfer substrate according to claim 2, characterized in that: The near-infrared absorbing dye includes at least one of the following: diimide ion complexes and their derivatives or salts, dithioene complexes and their derivatives or salts, and phthalocyanines and their derivatives or salts.

4. The transfer substrate according to any one of claims 1 to 3, characterized in that: The transfer substrate is a rigid substrate, a flexible substrate, a substrate with a rigid layer and a flexible layer, or a substrate with a rigid layer and a flexible film.

5. A transfer substrate according to claim 1, characterized in that: The local space pressure is greater than 1.1 standard atmospheres.

6. A transfer substrate according to claim 1, characterized in that: The local space pressure is greater than 1.2 standard atmospheres.

7. A transfer substrate according to claim 1, characterized in that: The roughness of the groove is Sa, which is 0.2μm-0.8μm, and Sz, which is less than 1.6μm.

8. A transfer substrate according to any one of claims 1 to 3, characterized in that: It also includes an antireflective coating, which is disposed on the surface of the transfer substrate opposite to the trench.

9. The transfer substrate according to claim 1, characterized in that: The total weight of the conductive metallic component and the inorganic binder in the printing paste accounts for 88-95 wt%.

10. A transfer method, characterized in that: The method includes filling a groove in a transfer substrate with a printing paste, releasing the printing paste from the groove onto a receiving substrate when irradiated by a laser beam, the printing paste containing organic release components, wherein the printing paste is at least partially vaporized when irradiated by the laser beam, and generating a local space pressure in the gap space between the printing paste and the groove, the local space pressure being greater than 1.05 standard atmospheres. The roughness of the groove is Sa = 0.02μm-2μm and Sz = less than 4μm.

11. A transfer method according to claim 10, characterized in that: The laser beam irradiation is near-infrared irradiation, and the organic release component is a near-infrared absorbing dye. The organic release component decomposes and vaporizes during laser beam irradiation.

12. The transfer method according to claim 11, characterized in that: The near-infrared absorbing dye includes at least one of the following: diimide ion complexes and their derivatives or salts, dithioene complexes and their derivatives or salts, and phthalocyanines and their derivatives or salts.

13. The transfer method according to claim 10, characterized in that: The total weight of the conductive metallic component and the inorganic binder in the printing paste accounts for 88-95 wt%.

14. The transfer method according to claim 10, characterized in that: The local space pressure is greater than 1.1 standard atmospheres.

15. The transfer method according to claim 10, characterized in that: The local space pressure is greater than 1.2 standard atmospheres.

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