Release film, method for producing same, and packaging apparatus

Abstract

m and a method of manufacturing the same, and a packaging apparatus.SOLUTION: The release film includes a PET base layer and a release layer. The release layer is formed by applying a coating liquid to the PET substrate layer. The coating liquid includes a matrix material and inorganic particles dispersed in the matrix material. The glass transition temperature of the matrix material is -60°C to -30°C. The average particle diameter of the inorganic particles is 8 μm to 12 μm. The thickness of the release layer is 5 μm to 20 μm, and the surface roughness (Ra) of the release layer is 0.4 μm to 0.8 μm. The release layer of the release film can be used in contact with an epoxy resin, and a peel strength between the release layer and the epoxy resin is 50 gf / inch to 400 gf / inch.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a release film, a method for producing the same, and a packaging device, and more particularly to a release film having excellent releasability from epoxy resin, a method for producing the same, and a packaging device. [Background technology]

[0002] Conventional release films are composed of a base material layer and a release layer formed on the base material layer, but because the surface of the release layer is too flat, the sealing resin (epoxy resin, etc.) remains on the surface of the release layer, making it difficult for gas to escape. Also, because the adhesion when the release film and the carrier of the packaged element are pressure-sealed is insufficient, the sealing resin easily leaks out of the grooves in the mold, causing surface defects. Summary of the Invention [Problem to be solved by the invention]

[0003] The technical problem that the present invention aims to solve is to provide a release film, a method for producing the same, and a packaging device that can overcome the shortcomings of the prior art, namely, the problem of excessively high fluidity on the surface of the release layer of the sealing resin and the problem that the sealing resin is prone to leak out of the grooves of the mold, which are problems that exist in prior art release films. [Means for solving the problem]

[0004] To solve the above technical problems, one technical solution adopted by the present invention is a release film, which includes a PET substrate layer and a release layer formed by applying a coating liquid to the PET substrate layer, the coating liquid including a matrix material having a glass transition temperature of −60° C. to −30° C. and inorganic particles dispersed in the matrix material, the inorganic particles having an average particle size of 8 μm to 12 μm, the release layer having a thickness of 5 μm to 20 μm, and a surface roughness (Ra) of 0.4 μm to 0.8 μm, the release layer of the release film being capable of contacting an epoxy resin, and the peel strength between the release layer and the epoxy resin being 50 gf / inch to 400 gf / inch.

[0005] Preferably, the number average molecular weight of the matrix material is 900 to 1,100, and the weight average molecular weight of the matrix material is 90,000 to 110,000.

[0006] Preferably, the matrix material is at least one selected from the group consisting of butyl acrylate (BA), n-butyl methacrylate (BMA), and 2-hydroxyethyl acrylate (2HEA), and the inorganic particles are silicon dioxide particles.

[0007] Preferably, when the total weight of the coating liquid is 100 wt %, the content of the matrix material is 70 wt % to 95 wt %, and the content of the inorganic particles is 1 wt % to 12 wt %.

[0008] Preferably, the coating liquid further contains a crosslinking agent and a lubricant, and the content of the crosslinking agent is 8 wt% to 15 wt%, and the content of the lubricant is 0.1 wt% to 5 wt%, assuming the total weight of the coating liquid to be 100 wt%.

[0009] Preferably, the material of the PET base layer is LL216 PET resin manufactured by Nanya Plastics, and based on the measurement standard ASTM D1204, the thermal deformation rate of the release film in the longitudinal direction is 0.4% to 0.6%, and the thermal deformation rate of the release film in the transverse direction is 0.15% to 0.25%.

[0010] Another technical solution adopted by the present invention to solve the above technical problems is to provide a packaging device, which includes a packaging mold having a recessed receiving groove and a release film placed in the receiving groove, the release film including a PET substrate layer placed at the bottom of the receiving groove of the packaging mold and a release layer formed by applying a coating liquid to the PET substrate layer, the coating liquid including a matrix material having a glass transition temperature (Tg) of −60°C to −30°C and inorganic particles dispersed in the matrix material, the inorganic particles having an average particle size of 8 μm to 12 μm, the release layer having a thickness of 5 μm to 20 μm, and a surface roughness (Ra) of 0.4 μm to 0.8 μm, the release layer of the release film being usable so as to come into contact with an epoxy resin, and the peel strength between the release layer and the epoxy resin being 50 gf / inch to 400 gf / inch.

[0011] In order to solve the above technical problems, yet another technical means adopted by the present invention is to provide a method for producing a release film. The method for producing a release film includes a coating solution preparation step of adding inorganic particles having an average particle size of 8 μm to 12 μm to a solvent, stirring the mixture at a rotation speed of 1,000 rpm to 2,000 rpm for 2 to 8 minutes, further adding a matrix material having a glass transition temperature (Tg) of -60°C to 30°C, and stirring the mixture at a rotation speed of 1,000 rpm to 2,000 rpm for 12 to 18 minutes to form a coating solution, and a coating step of applying the coating solution to a PET substrate layer to form a release layer on the PET substrate layer to form a release film, wherein the release layer has a thickness of 5 μm to 20 μm and a surface roughness (Ra) of 0.4 μm to 0.8 μm, and the release layer of the release film can be used so as to come into contact with an epoxy resin, and the peel strength between the release layer and the epoxy resin is 50 gf / inch to 400 gf / inch.

[0012] Preferably, the number average molecular weight of the matrix material is 900 to 1,100, and the weight average molecular weight of the matrix material is 90,000 to 110,000.

[0013] Preferably, the matrix material is at least one selected from the group consisting of butyl acrylate (BA), n-butyl methacrylate (BMA), and 2-hydroxyethyl acrylate (2HEA), and the inorganic particles are silicon dioxide particles.

[0014] Preferably, when the total weight of the coating liquid is 100 wt %, the content of the matrix material is 70 wt % to 95 wt %, and the content of the inorganic particles is 1 wt % to 12 wt %.

[0015] Preferably, in the coating liquid preparation step, after adding the matrix material, a lubricant and a crosslinking agent are further added and stirred for 8 to 12 minutes at a rotation speed of 1,000 rpm to 2,000 rpm to prepare the coating liquid, and the content of the crosslinking agent is 8 wt% to 15 wt% and the content of the lubricant is 0.1 wt% to 5 wt% when the total weight of the coating liquid is 100 wt%.

[0016] Preferably, the material of the PET base layer is LL216 PET resin manufactured by Nanya Plastics, and based on the measurement standard ASTM D1204, the thermal deformation rate of the release film in the longitudinal direction is 0.4% to 0.6%, and the thermal deformation rate of the release film in the transverse direction is 0.15% to 0.25%. [Effects of the Invention]

[0017] One of the advantageous effects of the present invention is that the release film, its manufacturing method, and packaging device according to the present invention have the technical features that "the glass transition temperature (Tg) of the matrix material is -60°C to -30°C" and "the average particle size of the inorganic particles is 8 μm to 12 μm," thereby improving the problems of conventional release films, such as excessively high fluidity on the surface of the release layer of the sealing resin, and the tendency of the sealing resin to leak out of the grooves of the mold. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic view of a release film according to an embodiment of the present invention. [Figure 2A] 1 is a schematic diagram of a packaging device according to an embodiment of the present invention; [Figure 2B] 1 is a schematic diagram illustrating a packaging device according to an embodiment of the present invention packaging a chip; [Figure 3] 1 is a flowchart of a method for producing a release film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] To better understand the features and technical contents of the present invention, please refer to the following detailed description of the present invention and the accompanying drawings, which are provided for reference and explanation only and do not limit the scope of the present invention.

[0020] The following describes the implementation of the "release film, its manufacturing method, and packaging device" according to the present invention through certain specific embodiments, and those skilled in the art can understand the advantages and effects of the present invention based on the content disclosed herein. The present invention can be implemented or applied through other different specific embodiments, and various modifications and changes can be made to the details herein based on different perspectives and applications without departing from the concept of the present invention. It should be noted in advance that the accompanying drawings of the present invention are for simple schematic illustrations and are not drawn to actual size. The technical content of the present invention will be described in more detail based on the following embodiments, but the scope of protection of the present invention is not limited by the disclosed content.

[0021] It should be understood that although the present specification may use terms such as "first," "second," and "third" to describe various elements or signals, these elements or signals are not limited by these terms. These terms are primarily used to distinguish one element from another element or one signal from another signal. Furthermore, the term "or" used in this specification may include any one or more combinations of the associated listed items, depending on the actual situation.

[0022] [Release film] As shown in Figure 1, an embodiment of the present invention provides a release film 100. The release film 100 includes a PET substrate layer 1 and a release layer 2. The release film 100 can be applied to a packaging process, but the present invention is not limited thereto.

[0023] The thickness of the PET substrate layer 1 is 25 μm to 250 μm. Preferably, the thickness of the PET substrate layer 1 is 30 μm to 100 μm. More preferably, the thickness of the PET substrate layer 1 is approximately 38 μm. The material of the PET substrate layer 1 is LL216 PET resin manufactured by Nanya Plastics, but the present invention is not limited to this.

[0024] The release layer 2 is formed by applying a coating liquid to the PET substrate layer 1. The coating liquid contains a matrix material 21 and inorganic particles 22 dispersed in the matrix material 21. Dispersing the inorganic particles 22 in the matrix material 21 increases the surface roughness of the surface of the release layer 2 away from the PET substrate layer 1, thereby adjusting the flowability of the encapsulating resin (e.g., epoxy resin) on the release layer 2. In other words, if the inorganic particles 22 are not dispersed in the matrix material 21, the surface of the release layer 2 away from the PET substrate layer 1 will be too flat, causing the encapsulating resin to flow and fill gaps, making it difficult for gas remaining on the surface to escape. In addition, the inorganic particles 22 create slight irregularities on the surface of the release layer 2, which remain slight irregularities even after the surface of the encapsulating resin contacts the surface of the release film 100, thereby improving the contrast of fonts during laser engraving.

[0025] The glass transition temperature (Tg) of the matrix material 21 is −60° C. to −30° C. It is noteworthy that because the matrix material 21 has a relatively low glass transition temperature (for example, −60° C. to −30° C.), the release layer 2 is relatively flexible and can be attached to the package carrier more closely, making it difficult for the encapsulating resin to leak out of the mold groove.

[0026] In this embodiment, the number average molecular weight of the matrix material 21 may be 900 to 1,100, and the weight average molecular weight of the matrix material 21 may be 90,000 to 110,000, but the present invention is not limited thereto.

[0027] In this embodiment, the matrix material 21 may be at least one selected from the group consisting of butyl acrylate (BA), n-butyl methacrylate (BMA), and 2-hydroxyethyl acrylate (2HEA), but the present invention is not limited thereto.

[0028] The inorganic particles 22 have an average particle size of 8 μm to 12 μm. Preferably, the inorganic particles 22 may have an average particle size of about 9 μm, but the present invention is not limited thereto. If the average particle size of the inorganic particles 22 is too high or too low, the surface roughness of the release layer 2 will be too high or too low. The inorganic particles 22 may be, for example, silicon dioxide particles.

[0029] The thickness of the release layer 2 is 5 μm to 20 μm, and the surface roughness (Ra) of the release layer 2 is 0.4 μm to 0.8 μm. Preferably, the thickness of the release layer 2 is 8 μm to 15 μm, and the surface roughness (Ra) of the release layer 2 is 0.5 μm to 0.7 μm. More preferably, the thickness of the release layer 2 is approximately 12 μm.

[0030] When the total weight of the coating liquid is taken as 100 wt%, the content of the matrix material 21 may be 70 wt% to 95 wt%, and the content of the inorganic particles 22 may be 1 wt% to 12 wt%. Preferably, when the total weight of the coating liquid is taken as 100 wt%, the content of the matrix material 21 is 70 wt% to 85 wt%, and the content of the inorganic particles 22 is 5 wt% to 11.11 wt%. More preferably, when the total weight of the coating liquid is taken as 100 wt%, the content of the matrix material 21 is 75.00 wt% to 80.00 wt%, and the content of the inorganic particles 22 is 5.88 wt% to 11.11 wt%.

[0031] In one embodiment, the coating liquid may further contain a crosslinker and a lubricant. The crosslinker content is 8 wt% to 15 wt% and the lubricant content is 0.1 wt% to 5 wt% of the total weight of the coating liquid (100 wt%). Preferably, the crosslinker content is 9.2 wt% to 10.96 wt% and the lubricant content is 0.1 wt% to 0.35 wt% of the total weight of the coating liquid (100 wt%).

[0032] It is worth noting that the release film 100 has a relatively low thermal deformation rate in both the longitudinal and transverse directions depending on the materials and content ranges of the PET substrate layer 1 and the release layer 2. If the thermal deformation rate of the release film 100 in the longitudinal direction or the transverse direction is too high, the release film 100 is likely to come off the packaging mold 200 during the packaging process. Specifically, according to the ASTM D1204 measurement standard, the thermal deformation rate of the release film 100 in the longitudinal direction is 0.4% to 0.6%, and the thermal deformation rate of the release film 100 in the transverse direction is 0.15% to 0.25%.

[0033] The release layer 2 of the release film 100 is used so as to come into contact with the epoxy resin E, and the peel strength between the release layer 2 and the epoxy resin E is 50 gf / inch to 400 gf / inch.

[0034] [Packaging equipment] 2A and 2B, FIG. 2A is a schematic diagram of a packaging device according to an embodiment of the present invention, and FIG. 2B is a schematic diagram of the packaging device according to an embodiment of the present invention packaging a chip. An embodiment of the present invention further provides a packaging device 1000. The packaging device 1000 includes a release film 100 and a packaging mold 200. The packaging mold 200 has a recessed receiving groove 201, and the release film 100 is placed in the receiving groove 201.

[0035] The release film 100 includes a PET substrate layer 1 and a release layer 2. The PET substrate layer 1 is placed on the bottom surface of the receiving groove 201 of the packaging mold 200. The PET substrate layer 1 has a thickness of 38 μm to 250 μm. The release layer 2 is formed by applying a coating liquid to the PET substrate layer 1. The coating liquid includes a matrix material 21 and inorganic particles 22 dispersed in the matrix material 21. The matrix material 21 has a glass transition temperature (Tg) of -60°C to -30°C, the inorganic particles 22 have an average particle size of 8 μm to 12 μm, the release layer 2 has a thickness of 5 μm to 20 μm, and the release layer 2 has a surface roughness (Ra) of 0.4 μm to 0.8 μm. The release layer 2 of the release film 100 is used so as to come into contact with the epoxy resin E, and the peel strength between the release layer 2 and the epoxy resin E is 50 gf / inch to 400 gf / inch.

[0036] The packaging device 1000 is used to package at least one chip C. Of course, in another embodiment, the packaging device 1000 can package multiple chips C at the same time, and the packaged multiple chips C can be cut in a subsequent process. The chip C may be placed on one side of a package carrier S, and the package carrier S may be placed on a carrying mold M. During the process in which the packaging device 1000 and the carrying mold M package the chip C together, the release film 100 is tightly attached to the package mold 200 and the package carrier S, and the epoxy resin E does not leak between the package mold 200 and the package carrier S.

[0037] [Release film manufacturing method] As shown in FIG. 3, FIG. 3 is a flowchart of a method for producing a release film according to an embodiment of the present invention. An embodiment of the present invention further provides a method for producing a release film. The release film 100 can be obtained by carrying out the method for producing a release film, but the present invention is not limited thereto. The method for producing a release film includes a coating liquid preparation step S110 and a coating step S120.

[0038] In the coating solution preparation step S110, inorganic particles 22 are added to a solvent and stirred at a rotation speed of 1,000 rpm to 2,000 rpm for 2 to 8 minutes, and then matrix material 21 is added and stirred at a rotation speed of 1,000 rpm to 2,000 rpm for 12 to 18 minutes to form a coating solution. The solvent may be, for example, ethyl acetate, but the present invention is not limited thereto.

[0039] Preferably, in the coating liquid preparation step S110, the inorganic particles 22 are added to a solvent and stirred at a rotation speed of about 1,500 rpm for about 5 minutes, and then the matrix material 21 is added and stirred at a rotation speed of about 1,500 rpm for about 15 minutes to form the coating liquid.

[0040] In the coating solution preparation step S110 according to one embodiment, after adding the matrix material 21, a lubricant and a crosslinking agent are further added and stirred at a rotation speed of 1,000 rpm to 2,000 rpm for 8 to 12 minutes to form the coating solution. Preferably, after adding the lubricant and the crosslinking agent, the coating solution is formed by stirring at a rotation speed of about 1,500 rpm for about 10 minutes.

[0041] When the total weight of the coating liquid is 100 wt%, the content of the matrix material may be 70 wt% to 95 wt%, the content of the inorganic particles may be 1 wt% to 12 wt%, the content of the crosslinking agent may be 8 wt% to 15 wt%, and the content of the lubricant may be 0.1 wt% to 5 wt%.

[0042] In the coating step S120, the coating liquid was applied to the PET substrate layer 1, thereby forming the release layer 2 on the PET substrate layer 1, and thus the release film 100 was formed.

[0043] [Measurement of experimental data] Hereinafter, the present invention will be described in detail with reference to Examples 1 to 5 and Comparative Examples 1 to 3. However, these Examples are provided for the purpose of understanding the present invention, and the present invention is not limited to these Examples.

[0044] Example 1: In the release film, the thickness of the release layer was 12 μm, the thickness of the PET substrate layer was 38 μm, and when the total weight of the release layer was 100 wt%, the content of matrix material was 84.28 wt%, the content of inorganic particles was 5.88 wt%, the content of lubricant was 0.10 wt%, the content of crosslinker was 9.74 wt%, and the average particle diameter of the inorganic particles was 9.56 μm.

[0045] Example 2: In the release film, the thickness of the release layer was 12 μm, the thickness of the PET substrate layer was 38 μm, and when the total weight of the release layer was 100 wt%, the content of matrix material was 83.06 wt%, the content of inorganic particles was 7.24 wt%, the content of lubricant was 0.10 wt%, the content of crosslinker was 9.60 wt%, and the average particle diameter of the inorganic particles was 9.56 μm.

[0046] Example 3: In the release film, the thickness of the release layer was 12 μm, the thickness of the PET substrate layer was 38 μm, and when the total weight of the release layer was 100 wt%, the content of matrix material was 81.87 wt%, the content of inorganic particles was 8.57 wt%, the content of lubricant was 0.10 wt%, the content of crosslinker was 9.46 wt%, and the average particle diameter of the inorganic particles was 9.56 μm.

[0047] Example 4: In the release film, the thickness of the release layer was 12 μm, the thickness of the PET substrate layer was 38 μm, and when the total weight of the release layer was 100 wt%, the content of matrix material was 80.72 wt%, the content of inorganic particles was 9.86 wt%, the content of lubricant was 0.10 wt%, the content of crosslinking agent was 9.32 wt%, and the average particle diameter of the inorganic particles was 9.56 μm.

[0048] Example 5: In the release film, the thickness of the release layer was 12 μm, the thickness of the PET substrate layer was 38 μm, and when the total weight of the release layer was 100 wt%, the content of matrix material was 79.59 wt%, the content of inorganic particles was 11.11 wt%, the content of lubricant was 0.10 wt%, the content of crosslinker was 9.20 wt%, and the average particle diameter of the inorganic particles was 9.56 μm.

[0049] Comparative Example 1: In the release film, the thickness of the release layer was 12 μm, the thickness of the PET substrate layer was 38 μm, the release layer did not contain inorganic particles, and when the total weight of the release layer was 100 wt%, the content of the matrix material was 84.8 wt%, and the content of the crosslinking agent was 15.20 wt%.

[0050] Comparative Example 2: In the release film, the thickness of the release layer was 8 μm, the thickness of the PET substrate layer was 38 μm, and the release layer did not contain inorganic particles. When the total weight of the release layer was 100 wt%, the content of the matrix material was 84.1 wt%, the content of the lubricant was 0.9 wt%, and the content of the crosslinking agent was 15.00 wt%.

[0051] Comparative Example 3: In the release film, the thickness of the release layer was 20 μm, the thickness of the PET base layer was 38 μm, and when the total weight of the release layer was 100 wt%, the content of matrix material was 83.18 wt%, the content of inorganic particles was 4.83 wt%, the content of crosslinking agent was 11.99 wt%, and the average particle diameter of the inorganic particles was 9.56 μm.

[0052] The compounding ratio of each component of the release films of Examples 1 to 5 and Comparative Examples 1 to 3, the thickness of the release layer, the thickness of the PET substrate layer, the particle diameter of the inorganic particles, the peel strength between the release layer and the epoxy resin, the surface roughness (Ra) of the release layer, the thermal deformation rate in the longitudinal direction and the thermal deformation rate in the lateral direction of the release film, the crosshatch test and hardness measurement, and related measurement methods are as described below.

[0053] Peel strength measurement: Peel strength at an angle of 90° was measured according to the ASTM D3330 standard.

[0054] Measurement of thermal deformation rate: Measured at a temperature of 150°C for 10 minutes according to ASTM D1204 standard.

[0055] Crosshatch test: measured according to ASTM D3359 standard.

[0056] Hardness measurement: Measured according to ASTM D3363 standard.

[0057] [Table 1-1] [Table 1-2]

[0058] [Consideration of measurement results] In Comparative Example 1, it was found that when particles were not added to the film surface, the surface roughness of the release layer was approximately 0.01 μm. This indicates that when particles were not added, the film surface was very flat and without irregularities. In addition, the hardness of the film surface was relatively high at 1H, which could cause problems such as adhesive leakage and residual bubbles at the edges during package measurement.

[0059] Comparative Example 2 shows that adding 0.9% lubricant to the formulation can significantly reduce the peel strength, but the problems of adhesive leakage at the edges and residual bubbles still exist.

[0060] In Comparative Example 3, it was found that when the thickness of the coating layer was greater than the thickness of the particles, the surface roughness of the film decreased to 0.085 μm. This indicated that if the coating layer was too thick, the particles could not be lifted from the coating layer, resulting in a decrease in roughness. However, when the main resin was replaced with a selected material, the hardness of the film surface decreased, allowing the film surface to adhere more firmly to the package carrier under lamination conditions, thereby improving the problem of adhesive leakage.

[0061] According to the examples, when the particle addition amount was adjusted, the film surface roughness gradually increased with increasing particle addition amount, and the surface roughness increased as more particles emerged. When the film surface roughness was greater than 0.400 μm and less than 1.6 μm, the appearance of the package was perfect, and there were no problems with residual bubbles or adhesive leakage.

[0062] [Advantageous Effects of the Embodiments] One of the advantageous effects of the present invention is that the release film, its manufacturing method, and packaging device according to the present invention have the technical features that "the glass transition temperature (Tg) of the matrix material is -60°C to -30°C" and "the average particle size of the inorganic particles is 8 μm to 12 μm," thereby improving the problems of conventional release films, such as excessive fluidity on the surface of the release layer of the sealing resin and leakage of the sealing resin outside the grooves of the mold.

[0063] The above disclosure is merely a preferred embodiment of the present invention, and the scope of the claims of the present invention is not limited thereto. Therefore, any equivalent technical modifications made using the specification and drawings of the present invention are included in the scope of the claims of the present invention. [Explanation of symbols]

[0064] 100...Packaging equipment 100...Release film 1...PET base material layer 2...Release layer 21...Matrix material 22...Inorganic particles 200...Package mold 201... Storage groove C...Chip E...Epoxy resin M...Carrying mold S...Package carrier S110...Coating liquid preparation process S120...Coating process

Claims

1. a PET substrate layer; a release layer formed by applying a coating liquid to the PET substrate layer, The coating liquid is a matrix material having a glass transition temperature (Tg) of −60° C. to −30° C.; and inorganic particles dispersed in the matrix material, the inorganic particles having an average particle size of 8 μm to 12 μm; The thickness of the release layer is 5 μm to 20 μm, and the surface roughness (Ra) of the release layer is 0.4 μm to 0.8 μm. The release layer can be used so as to come into contact with an epoxy resin, and the peel strength between the release layer and the epoxy resin is 50 gf / inch to 400 gf / inch.

2. 2. The release film according to claim 1, wherein the number average molecular weight of the matrix material is 900 to 1,100, and the weight average molecular weight of the matrix material is 90,000 to 110,000.

3. 2. The release film according to claim 1, wherein the matrix material is at least one selected from the group consisting of butyl acrylate (BA), n-butyl methacrylate (BMA), and 2-hydroxyethyl acrylate (2HEA), and the inorganic particles are silicon dioxide particles.

4. 2. The release film according to claim 1, wherein the content of the matrix material is 70 wt % to 95 wt % and the content of the inorganic particles is 1 wt % to 12 wt %, with the total weight of the coating liquid being 100 wt %.

5. 2. The release film according to claim 1, wherein the coating liquid further contains a crosslinking agent and a lubricant, and when the total weight of the coating liquid is 100 wt%, the content of the crosslinking agent is 8 wt% to 15 wt%, and the content of the lubricant is 0.1 wt% to 5 wt%.

6. 2. The release film according to claim 1, wherein the material of the PET base layer is LL216 PET resin manufactured by Nanya Plastics, and the thermal deformation rate of the release film in the longitudinal direction is 0.4% to 0.6%, and the thermal deformation rate of the release film in the transverse direction is 0.15% to 0.25%, based on the measurement standard of ASTM D1204.

7. a package mold having a recessed receiving groove; A packaging device including a release film installed in the receiving groove, The release film is a PET substrate layer disposed at the bottom of the receiving groove of the packaging mold; a release layer formed by applying a coating liquid to the PET substrate layer, the coating liquid contains a matrix material having a glass transition temperature (Tg) of −60° C. to −30° C. and inorganic particles dispersed in the matrix material, the inorganic particles having an average particle diameter of 8 μm to 12 μm, the release layer having a thickness of 5 μm to 20 μm, and the surface roughness (Ra) of the release layer being 0.4 μm to 0.8 μm; The release layer of the release film can be used to contact an epoxy resin, and the peel strength between the release layer and the epoxy resin is 50 gf / inch to 400 gf / inch.

8. a coating liquid preparation step of adding inorganic particles having an average particle size of 8 μm to 12 μm to a solvent, stirring the mixture at a rotation speed of 1,000 rpm to 2,000 rpm for 2 to 8 minutes, further adding a matrix material having a glass transition temperature (Tg) of −60° C. to 30° C., and stirring the mixture at a rotation speed of 1,000 rpm to 2,000 rpm for 12 to 18 minutes to form a coating liquid; a coating step of coating the coating liquid onto a PET substrate layer to form a release layer on the PET substrate layer, thereby forming a release film, The thickness of the release layer is 5 μm to 20 μm, and the surface roughness (Ra) of the release layer is 0.4 μm to 0.8 μm, The method for producing a release film, wherein the release layer of the release film can be used so as to come into contact with an epoxy resin, and the peel strength between the release layer and the epoxy resin is 50 gf / inch to 400 gf / inch.

9. 9. The method for producing a release film according to claim 8, wherein the number average molecular weight of the matrix material is 900 to 1,100, and the weight average molecular weight of the matrix material is 90,000 to 110,000.

10. 9. The method for producing a release film according to claim 8, wherein the matrix material is at least one selected from the group consisting of butyl acrylate (BA), n-butyl methacrylate (BMA), and 2-hydroxyethyl acrylate (2HEA), and the inorganic particles are silicon dioxide particles.

11. 9. The method for producing a release film according to claim 8, wherein, when the total weight of the coating liquid is 100 wt%, the content of the matrix material is 70 wt% to 95 wt%, and the content of the inorganic particles is 1 wt% to 12 wt%.

12. 9. The method for producing a release film according to claim 8, wherein in the coating liquid preparation step, after adding the matrix material, a lubricant and a crosslinking agent are further added and stirred for 8 minutes to 12 minutes at a rotation speed of 1,000 rpm to 2,000 rpm to prepare the coating liquid, and when the total weight of the coating liquid is 100 wt %, the content of the crosslinking agent is 8 wt % to 15 wt %, and the content of the lubricant is 0.1 wt % to 5 wt %.

13. 9. The method for producing a release film according to claim 8, wherein the material of the PET base layer is LL216 PET resin manufactured by Nanya Plastics, and the thermal deformation rate of the release film in the longitudinal direction is 0.4% to 0.6%, and the thermal deformation rate of the release film in the transverse direction is 0.15% to 0.25%, based on the measurement standard of ASTM D1204.

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