A sacrifice layer coating liquid, a preparation method thereof, a sacrifice layer film and application

Abstract

This invention relates to the field of flexible electronics technology, and more particularly to a sacrificial layer coating solution, its preparation method, sacrificial layer film, and its applications. The raw materials for preparing the sacrificial layer coating solution, by weight percentage, include: 5-14% functional substrate, with the remainder being solvent; the functional substrate exhibits a volatile content ≥95% after being placed at 250°C for 3 minutes. This invention selects ethyl α-cyanoacrylate as the functional substrate and constructs a sacrificial layer coating solution system with excellent coating and curing properties using a mixed solvent of acetone and acetonitrile. This sacrificial layer material possesses the characteristic of rapid and complete vaporization under low laser energy triggering, enabling high-precision pattern transfer with straight edges and minimal burrs, and leaving no significant residue after transfer. This effectively improves transfer accuracy, transfer process efficiency, and the cleanliness of the donor substrate, meeting the requirements for high-precision transfer applications.

Description

Technical Field

[0001] This invention relates to the field of flexible electronics technology, and in particular to a sacrificial layer coating liquid, its preparation method, sacrificial layer film, and its application. Background Technology

[0002] In Laser-Induced Forward Transfer (LIFT) technology, the sacrificial layer is a functional intermediate layer material. It is typically coated on the surface of the donor substrate and subsequently bonded to the functional layer to be transferred (such as a conductive pattern layer). When the process is triggered (e.g., by laser irradiation), the sacrificial layer rapidly vaporizes / decomposes, using the thrust generated by its vaporization to transfer the functional layer to the receiving substrate, while completely consuming itself and leaving no residue on the substrate—essentially "sacrificing itself to complete the functional layer transfer," hence the name "sacrificial layer." As one of the core functional layers for achieving fine conductive pattern transfer, the sacrificial layer must meet the key performance requirements of "rapid and complete vaporization at low laser energy, no residue after transfer, and ensuring pattern edge accuracy," while also considering coating uniformity and substrate compatibility to support the efficiency of the transfer process and the quality of the finished product.

[0003] In existing technologies, commonly used sacrificial layer materials (such as conventional resins like PVP) have several drawbacks: First, their thermal evaporation performance is insufficient, requiring high laser energy for vaporization, which can easily lead to thermal damage to the substrate. Incomplete vaporization can also leave impurities, affecting the reusability of the donor substrate. Second, the matching evaporation rate and solubility of the matching solvent system are poorly matched, making it easy for problems such as dry edges and sagging to occur during the coating process, and making it difficult to control the uniformity of film thickness. The transfer patterns obtained by existing processes have many burrs on the edges and low precision. At the same time, the process consumes a lot of energy and lacks stability, making it difficult to meet the needs of the flexible electronics field for fine patterns and efficient fabrication.

[0004] Chinese invention patent application CN106414356A discloses a method for obtaining a substrate coated with a functional layer using a sacrificial layer. By depositing an absorptive sacrificial layer on the functional layer and then performing heat treatment using a laser or flash lamp, it solves the problem of low heat treatment efficiency caused by the functional layer's non-absorption of infrared radiation, achieving simple removal of the sacrificial layer and heat treatment. Chinese invention patent CN110931418B discloses a method for preparing a flexible display panel, a sacrificial layer material, and its preparation method. By using a sacrificial layer material and vacuum heat treatment technology in the fabrication of the flexible display panel, it solves the problems of ablation and warping of the flexible substrate caused by laser lift-off, improving yield and reducing costs. However, these existing technologies have not solved the technical problems of high sacrificial layer vaporization threshold, excessive residue after transfer, poor pattern accuracy, and difficulty in balancing process stability with the requirements of industrial applications in laser-induced thermal transfer processes.

[0005] Against this backdrop, there is an urgent need to provide a low-threshold, low-residue, and high-stability sacrificial layer material suitable for high-precision laser-induced thermal transfer, as well as its preparation method and application. Summary of the Invention

[0006] This invention aims to overcome the shortcomings of existing technologies and provide a sacrificial layer material suitable for LIFT processes, as well as a method for preparing and applying this material. This sacrificial layer material possesses the characteristic of rapid and complete vaporization under low laser energy triggering, enabling high-precision pattern transfer with straight edges and minimal burrs, and leaving no obvious residue after transfer. This effectively improves transfer accuracy, transfer process efficiency, and the cleanliness of the donor substrate, meeting the requirements for high-precision transfer applications.

[0007] The first aspect of the present invention provides a sacrificial layer coating liquid, wherein the raw materials for preparing the sacrificial layer coating liquid include, by weight percentage: 5-14% functional main body and the balance being solvent.

[0008] Optionally, the mass evaporation rate of the functional body after being placed at 250°C for 3 minutes is ≥95%.

[0009] In existing technologies, sacrificial layer materials used in laser-induced thermal transfer printing generally suffer from problems such as high thermal evaporation threshold, incomplete vaporization, and significant residue after transfer, resulting in low transfer sensitivity and poor pattern accuracy, making it difficult to meet the requirements of high-precision transfer processes. To address these issues, this invention selects a functional substrate material with a mass evaporation rate ≥95% after being placed at a constant temperature of 250°C for 3 minutes. This material is then compounded with a suitable solvent to prepare a coating solution. By improving the thermal evaporation performance of the functional substrate and the compatibility with the solvent, the film-forming properties and stability of the coating solution are optimized, effectively improving the vaporization performance of the sacrificial layer and thus optimizing the transfer effect.

[0010] Further optionally, the mass evaporation rate of the functional body after being placed at 250°C for 3 minutes is ≥99%.

[0011] Optionally, the raw materials for preparing the sacrificial layer coating liquid include: 8-12% functional bulk and the remainder for solvent replenishment.

[0012] Optionally, the raw materials for preparing the sacrificial layer coating liquid include: 10% functional bulk and the remainder solvent.

[0013] Optionally, the functional subject includes α-substituted acrylate compounds.

[0014] Further optionally, the α-substituted acrylate compound includes one or more combinations of α-cyanoacrylate, α-methacrylate, α-chloroacrylate, α-hydroxyacrylate, and α-phenylacrylate.

[0015] Most preferably, the α-substituted acrylate compound is ethyl α-cyanoacrylate, and the ethyl α-cyanoacrylate has a mass volatile rate of 99.15% after being placed at 250°C for 3 minutes.

[0016] Furthermore, this invention preferably uses ethyl α-cyanoacrylate as the functional component and combines it with a specific mixed solvent to construct the coating system. The ethyl α-cyanoacrylate film in this system achieves a mass evaporation rate of over 99.15% at 250°C for 3 minutes, far exceeding that of traditional resins such as PVP (polyvinylpyrrolidone) and conventional acrylates (which have an evaporation rate of only 20%-90% under the same conditions and require higher temperatures for complete decomposition). This unique combination not only achieves excellent coating performance and film smoothness of the coating solution but also endows the sacrificial layer with an extremely low thermal evaporation threshold and near-complete evaporation characteristics, allowing it to instantly and completely vaporize under the limited heat transferred from the absorption layer. This provides a core material basis for high-sensitivity and high-cleanliness transfer effects.

[0017] Optionally, the solvent includes one or more combinations of acetone, acetonitrile, ethanol, isopropanol, propylene glycol methyl ether, propylene glycol methyl ether acetate, ethyl acetate, methyl ethyl ketone, cyclohexanone, N,N-dimethylformamide, N-methylpyrrolidone, and tetrahydrofuran.

[0018] Further optionally, the solvent is acetone and acetonitrile, wherein the mass ratio of acetone to acetonitrile is 1:(0.5-2); more preferably, it is 1:1.

[0019] This invention also optimizes the solvent system, using a mixed solvent of acetone and acetonitrile at a mass ratio of 1:(0.5-2) (the optimal mass ratio is 1:1), combined with 10 wt% ethyl α-cyanoacrylate to construct the sacrificial layer coating solution. Experiments have shown that this ratio is the core key to achieving excellent coating rheology, film uniformity, and controllable evaporation rate. The mixing ratio of acetone and acetonitrile directly affects the overall volatility of the coating solution, its wetting properties on the substrate, and the solubility stability of ethyl α-cyanoacrylate. Only by dissolving and dispersing ethyl α-cyanoacrylate using a specific solvent mixture can the technical effects of good solubility and stability be achieved, providing a reliable solution basis for subsequent coating processes.

[0020] A second aspect of the present invention provides a method for preparing a sacrificial layer coating solution, wherein the preparation steps of the sacrificial layer coating solution include: The functional component is added to the solvent and stirred until it is dissolved evenly to obtain the sacrificial layer coating solution.

[0021] In some embodiments, the sacrificial layer coating solution is clear and transparent.

[0022] A third aspect of the present invention provides a sacrificial layer film, wherein the preparation steps of the sacrificial layer film include: S1. Provide a donor substrate, wherein the donor substrate is a polymer film with a laser absorption layer on its surface; S2. Apply the sacrificial layer coating liquid to the surface of the laser absorption layer; S3. Allow the solution to stand until the solvent in the sacrificial layer coating liquid has completely evaporated, forming a wet sacrificial layer film; S4. The wet sacrificial layer film is atomized to form a dry sacrificial layer film.

[0023] Optionally, the laser absorption layer is made of at least one of chromium (Cr), molybdenum (Mo), gold (Au), silver (Ag), titanium (Ti), aluminum (Al), and nickel (Ni).

[0024] Alternatively, the laser absorption layer may be made of chromium (Cr) or molybdenum (Mo).

[0025] In some embodiments, the polymer film may be exemplified as polyethylene terephthalate (PET) film.

[0026] Optionally, in step S2, the sacrificial layer coating liquid is applied to the surface of the laser absorption layer using a wire bar coating method; the depth of the wire bar is 5-7 μm, and 450-550g of counterweight is applied to both ends of the wire bar during the coating process, with a coating speed of 1.8-2.2 m / min.

[0027] The technical effects of this invention also require a precise and controllable coating process. By optimizing the depth of the squeegee on the wire rod to 5-7 μm, applying a counterweight of 450-550g to each end of the wire rod during the squeegee coating process, and setting the squeegee speed to 1.8-2.2 m / min, precise control of the sacrificial layer film thickness and excellent coating uniformity are achieved, providing a key process guarantee for batch consistency in subsequent laser transfer printing.

[0028] Further optionally, the coating tooth depth of the wire bar is 6μm, and a counterweight of 500g is applied to each end of the wire bar during the coating process, with a coating speed of 2m / min.

[0029] In some embodiments, the counterweights at both ends of the bar can be applied by means of weights or other methods. There are no particular restrictions on the method of application, as long as the purpose of counterweighting is achieved.

[0030] Optionally, the settling time is 3-7 seconds, and more preferably 5 seconds.

[0031] Optionally, the atomization treatment is water vapor atomization treatment, and the treatment time is 4-6 minutes; more preferably 5 minutes. During the treatment, the wet sacrificial film is rapidly solidified under the catalysis of water to form a stable dry sacrificial film.

[0032] This invention further optimizes the curing stage of the film by utilizing the rapid polymerization characteristic of ethyl α-cyanoacrylate in the presence of water and employing water vapor atomization treatment to promote the curing of the wet film into a stable dry film in a short time. More importantly, the film treated with this process exhibits excellent room temperature stability, with a natural evaporation rate of less than 10% after 20 hours at room temperature; while the coating without water vapor treatment shows an evaporation rate exceeding 25% after 2 hours at room temperature, failing to meet practical storage and usage requirements. This post-treatment step effectively overcomes the technical difficulties of easy volatility and poor stability after coating with ethyl α-cyanoacrylate, providing a feasible guarantee for the industrial application of this coating solution.

[0033] In some embodiments, S4 places the sacrificial wet film in a humidity-controlled environment for water vapor atomization treatment.

[0034] In some embodiments, a pure water atomizer is used to atomize the sacrificial layer wet film.

[0035] The fourth aspect of the present invention provides an application of the sacrificial layer coating liquid or sacrificial layer film as described above, applied to a laser-induced thermal transfer process.

[0036] The fifth aspect of the present invention provides a finely conductive patterned layer, which is prepared using a donor plate containing a sacrificial layer film as described above.

[0037] Beneficial effects: This invention provides a sacrificial layer coating solution, its preparation method, a sacrificial layer film, and its application, which have the following advantages: (1) In this invention, a functional host material with a mass evaporation rate of ≥95% after being placed at a constant temperature of 250℃ for 3 minutes is selected and mixed with a suitable solvent to prepare a coating liquid. By improving the thermal evaporation performance of the functional host and the compatibility of the solvent, the film-forming properties and stability of the coating liquid are optimized, and the vaporization performance of the sacrificial layer is effectively improved, thereby optimizing the transfer effect. After trying, it was found that the optimal effect can be achieved by selecting ethyl α-cyanoacrylate as the functional host and acetone and acetonitrile as the solvent in a mass ratio of 1:(0.5-2).

[0038] (2) Ultra-high volatility and cleanliness: The volatile rate of ethyl α-cyanoacrylate in this system can reach 99.15% after being placed at 250℃ for 3 minutes. It is almost completely volatilized, which can ensure that there is no obvious residue in the sacrificial layer after laser treatment. The donor substrate has high cleanliness and can be reused. At the same time, it avoids the residue from having an adverse effect on the electrical properties of the transfer pattern.

[0039] (3) High sensitivity and low energy consumption: The vaporization threshold of the sacrificial layer of the present invention is extremely low, and the required laser energy can be reduced by 30%–50% compared with traditional materials such as PVP. This not only saves energy, but also reduces the risk of thermal damage to the functional layer and substrate by laser, thus broadening the applicable process window of the thermal sensitive material.

[0040] (4) Excellent transfer pattern quality: This invention relies on the clean and directional gas thrust generated by the instantaneous and complete vaporization of the sacrificial layer. The edges of the metal electrode lines obtained by transfer are straight, and the burrs and sputtering phenomena are significantly reduced, effectively avoiding the pattern deformation problem caused by material melting, partial decomposition or uneven vaporization.

[0041] (5) Good processability and stability: By optimizing the coating parameters and water vapor curing process, this invention achieves high uniformity and high reproducibility in the preparation of the sacrificial layer film; the cured film has excellent room temperature storage stability, which can meet the requirements of industrial production for material processability and stability.

[0042] (6) Synergistic effect: The present invention forms a significant technical synergistic effect through the selection of specific materials, the optimization design of specific formulations, and the organic combination of specific coating processes and curing processes. This results in the final sacrificial layer having a comprehensive excellent performance in the LIFT process, including an extremely low transfer energy threshold, extremely high pattern transfer accuracy (straight edges, no burrs), and almost zero residue on the donor substrate after transfer.

[0043] (7) Significant cost-effectiveness: The use of commercial chemical product ethyl α-cyanoacrylate as the core material ensures controllable raw material costs; at the same time, the simplification of coating and curing processes helps to further reduce industrial production costs and meet the requirements of mass production. Attached Figure Description

[0044] Figure 1 A sample image of the transfer print from Example 1; Figure 2 Actual transfer image of Example 4; Figure 3 A copy of the transfer image from Comparative Example 1; Figure 4 A comparison image of the transfer print from Example 2; Figure 5 Microscopic images of the transfer effect in the control group (with excessive laser energy); Figure 6 Image of the transfer sample from the control group (where the laser energy was too high). Detailed Implementation

[0045] Unless otherwise specified, all raw materials, equipment and other consumables used in this invention are commercially available.

[0046] Example 1 This embodiment provides a sacrificial layer coating liquid, its preparation method, and a sacrificial layer film.

[0047] The raw materials for preparing the sacrificial layer coating liquid, by weight percentage, include: 10% functional bulk and the remainder solvent.

[0048] The functional component is ethyl α-cyanoacrylate (CAS No.: 7085-85-0), and the ethyl α-cyanoacrylate has a mass volatile rate of 99.15% after being placed at 250°C for 3 minutes.

[0049] The solvent is acetone and acetonitrile in a mass ratio of 1:1.

[0050] The preparation steps of the sacrificial layer coating solution include: Add 5g of the functional subject to 45g of solvent and stir magnetically for 10 minutes to dissolve evenly, resulting in a clear and transparent sacrificial layer coating solution.

[0051] The steps for preparing the sacrificial layer film include: S1. Provide a donor substrate, wherein the donor substrate is a PET film with a laser absorption layer (made of Cr) deposited on its surface; wherein the thickness of the PET film is 125 μm and the thickness of the laser absorption layer is 100 nm; S2. The sacrificial layer coating liquid is applied to the surface of the laser absorption layer using a wire bar coating method; the depth of the wire bar coating teeth is 6μm, and 500g weights are loaded at both ends of the wire bar during the coating process, with a coating speed of 2m / min. S3. After coating, let stand for 5 seconds to allow the solvent in the sacrificial layer coating solution to evaporate completely, forming a sacrificial layer wet film; S4. The donor substrate containing the sacrificial wet film is transferred to the atomization chamber, and pure water mist is sprayed out using an ultrasonic atomizer for water vapor atomization treatment for 5 minutes. During the treatment, the sacrificial wet film is rapidly solidified under the catalysis of water to form a sacrificial film (dry film).

[0052] Example 2 This embodiment provides a sacrificial layer coating liquid, its preparation method, and a sacrificial layer film. The specific implementation method is the same as in Embodiment 1; the difference is that the amount of solvent added is kept constant, and the solvent is set to acetone and acetonitrile in a mass ratio of 3:1.

[0053] Example 3 This embodiment provides a sacrificial layer coating liquid and its preparation method and a sacrificial layer film. The specific implementation method is the same as that in Embodiment 1; the difference is that the amount of the functional subject added is 15wt% and the solvent is 85wt%.

[0054] Example 4 This embodiment provides a sacrificial layer coating liquid, its preparation method, and a sacrificial layer film. The specific implementation method is the same as that in Embodiment 1; the difference is that the functional main body is polyvinylpyrrolidone (PVP K30, from Beijing Bailingwei Technology Co., Ltd.); and the solvent is isopropanol.

[0055] The steps for preparing the sacrificial layer film include: Steps S1 and S2 are the same as in Example 1; S3. After coating, dry at 60°C for 1 minute to form a sacrificial layer film.

[0056] Example 5 This embodiment provides a sacrificial layer coating liquid, its preparation method, and a sacrificial layer film. The specific implementation method is the same as in Embodiment 1; the difference is that step S4 is omitted.

[0057] Comparative Example 1 This comparative example provides a sacrificial layer coating solution, which, by weight percentage, comprises: 20 g / L acrylic resin and terpineol as solvent.

[0058] The acrylic resin has a thermal decomposition initiation temperature >200°C, is sourced from Mitsubishi Chemical, and is designated as BR115.

[0059] The sacrificial layer film is prepared using this sacrificial layer material, and the preparation steps include: Steps S1 and S2 are the same as in Example 1; S3. After coating, dry at 250℃ for 10 minutes to form a sacrificial layer film.

[0060] Comparative Example 2 Pure methyl α-cyanoacrylate was used as the coating solution (without adding solvent) to prepare a sacrificial layer film (preparation method is the same as in Example 1) and then tested.

[0061] Comparative Example 3 Methyl α-cyanoacrylate was dissolved in the following three solvents, with the concentration of methyl α-cyanoacrylate controlled at 10 wt% in each solvent; its dispersibility was then tested.

[0062] (1) Acetone; (2) Acetonitrile; (3) A mixture of acetone and acetonitrile in a mass ratio of 1:1.

[0063] Tests revealed that methyl α-cyanoacrylate has poor solubility in solvents (1) to (3). Even with prolonged stirring or ultrasonic treatment, it can only form a milky white unstable suspension or a turbid solution. After standing, the solution quickly separates into layers or precipitates, making it impossible to obtain a clear, uniform, and stable coating solution.

[0064] Because the solution prepared in Comparative Example 3 was unstable and could not be effectively coated, subsequent film formation tests were not conducted. This result demonstrates, on the one hand, the selectivity of ethyl α-cyanoacrylate, indicating that other structurally similar materials cannot achieve the same effect; on the other hand, it proves that this invention requires a specific solvent system to dissolve ethyl α-cyanoacrylate, as other solvents have poor compatibility with this system and fundamentally lack the possibility of a repeatable coating process.

[0065] Performance testing 1. Curing effect The surface morphology of the sacrificial layer film during and after curing in each embodiment and comparative example was observed using an optical profilometer and a white light interferometer to evaluate the curing effect.

[0066] 2. Thermal volatility Take the cured film samples from the examples and comparative examples, place them in an oven at 250°C for 3 minutes, cool and weigh them, and calculate their mass loss rate; the test results are shown in Table 1.

[0067] 3. Storage stability The cured film samples from the examples and comparative examples were placed at 25°C and 50%RH for 20 hours, and their mass loss rate was calculated; the test results are shown in Table 1.

[0068] 4. LIFT transfer test The sacrificial layer film prepared in the example was subjected to LIFT transfer printing test. The test steps are as follows: (1) Take the sacrificial layer film prepared in the examples and comparative examples, spin-coat a layer of nano silver conductive ink (from Guangdong Nanhai Qiming Guangda Technology Co., Ltd., the nano silver particles in the ink are distributed in the range of 5~20nm, the solvent is cyclohexane, and the concentration is 25wt%) and dry to form a functional layer. (2) A pulsed laser with a wavelength of 1064 nm was used to selectively irradiate the functional layer onto the PI (polyimide) acceptor membrane through a mask (the laser single pulse energy of each sample is shown in Table 2). (3) After the transfer, the laser absorption layer in the donor substrate was observed by optical microscope and detected by XPS (X-ray photoelectron spectroscopy); the test results are shown in Table 2.

[0069] A control group was also set up: the sacrificial layer film prepared in Example 1 was transferred using laser energy 20 times that of Example 1. The test results are shown in [Figure 1]. Figure 5 , Figure 6 .

[0070] Table 1

[0071] Table 2

[0072] The test results in Tables 1 and 2 show that not all materials with similar structures or properties (such as thermal volatility) can solve the technical problems of this invention. Extensive experimentation revealed that only by combining a specific functional substrate (ethyl α-cyanoacrylate) with a specific acetone / acetonitrile mixed solvent system can excellent solubility and stability be achieved. The resulting coating solution, combined with a wire rod coating process, can form a uniform wet film. After water vapor curing, a sacrificial dry film with excellent film smoothness is obtained, providing a good processing foundation for LIFT transfer and ultimately significantly improving the quality of the transferred pattern. This invention, with its high thermal volatility ethyl α-cyanoacrylate, combined with a specific solvent system and a specific coating process, constitutes a complete, feasible, and effective technical solution, ultimately improving the overall performance of the sacrificial film and meeting the requirements of high-precision transfer scenarios.

[0073] Analysis of the curing and LIFT transfer effects of the films in the examples and comparative examples reveals that the significant deterioration in the flatness of the cured film layer directly leads to uneven thickness distribution of the functional conductive layer (such as nano-silver ink) coated on its surface. In subsequent laser transfer processes, these defects are further amplified, ultimately causing problems such as inconsistent linewidths of the transferred conductive patterns, disordered resistance distribution, and even localized line breaks. This further confirms that optimizing the performance of the sacrificial layer film is a key prerequisite for achieving excellent transfer results.

[0074] The results of Comparative Example 3 further reveal the specificity of the material selection in this invention. Although methyl α-cyanoacrylate has similar thermal volatility to ethyl α-cyanoacrylate, its dispersibility in the specified solvent system is insufficient, and the film smoothness deteriorates significantly after water vapor curing. These two key process defects prevent it from meeting the stringent requirements of the LIFT process for sacrificial layer uniformity, stability, and interface quality. Therefore, this material is not suitable for the high-precision transfer scenarios involved in this invention. This further confirms that the combination of ethyl α-cyanoacrylate and a specific solvent system is the material basis for optimizing the performance of the sacrificial layer film and ensuring high-precision transfer results.

[0075] Figure 5 , Figure 6 Further demonstration of the transfer effect when laser energy is too high. Figure 5 When the laser energy is too high, the metal layer (Cr or Mo) of the substrate will burn through. Figure 5 The areas marked P1 and P3 are the metal layers that have been burned through. Moreover, the sacrificial layer will explode, eventually causing the conductive silver layer above the sacrificial layer to explode as well. The transferred silver layer will be discrete and unable to form a continuous metallic structure. Figure 6 ).

Claims

1. A sacrificial layer coating liquid, characterized in that, The raw materials for preparing the sacrificial layer coating liquid, by weight percentage, include: 5-14% functional bulk and the remainder for solvent replenishment; The mass evaporation rate of the functional component after being placed at 250°C for 3 minutes is ≥95%.

2. The sacrificial layer coating liquid according to claim 1, characterized in that, The functional group includes α-substituted acrylate compounds.

3. The sacrificial layer coating liquid according to claim 2, characterized in that, The α-substituted acrylate compound is ethyl α-cyanoacrylate, and the ethyl α-cyanoacrylate has a volatile content of 99.15% after being placed at 250°C for 3 minutes.

4. The sacrificial layer coating liquid according to claim 3, characterized in that, The solvent is acetone and acetonitrile, and the mass ratio of acetone to acetonitrile is 1:(0.5-2).

5. A method for preparing the sacrificial layer coating liquid according to any one of claims 1-4, characterized in that, The preparation steps of the sacrificial layer coating solution include: The functional component is added to the solvent and stirred until it is dissolved evenly to obtain the sacrificial layer coating solution.

6. A sacrificial layer film, characterized in that, The steps for preparing the sacrificial layer film include: S1. Provide a donor substrate, wherein the donor substrate is a polymer film with a laser absorption layer on its surface; S2. Apply the sacrificial layer coating liquid according to any one of claims 1-4 to the surface of the laser absorption layer; S3. Allow the solution to stand until the solvent in the sacrificial layer coating liquid has completely evaporated, forming a wet sacrificial layer film; S4. The sacrificial layer wet film is atomized to form a sacrificial layer thin film.

7. The sacrificial layer film according to claim 6, characterized in that, S2 uses a wire bar coating method to coat the sacrificial layer coating liquid onto the surface of the laser absorption layer; The depth of the coating teeth on the bar is 5-7 μm. During the coating process, 450-550g of counterweight is applied to both ends of the bar, and the coating speed is 1.8-2.2 m / min.

8. The sacrificial layer film according to claim 6, characterized in that, The atomization process is water vapor atomization, and the processing time is 4-6 minutes.

9. The application of a sacrificial layer coating liquid according to any one of claims 1-4 or a sacrificial layer film according to any one of claims 6-8, characterized in that, It is applied to laser-induced thermal transfer processes.

10. A finely conductive patterned layer, characterized in that, It is prepared using a donor plate containing the sacrificial layer film as described in any one of claims 6-8.

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