Film removal method and film removal apparatus

Abstract

To obtain, for example, a new coating removal method and a coating removal device with less inconvenience.SOLUTION: The coating removal method is, for example, for removing an insulation coating of an electric wire by irradiating it with laser light. The wavelength of the laser light is preferably 533 nm or less. In addition, in the coating removal method, for example, it is more suitable if the wavelength of the laser light is 350 nm or more and 533 nm or less. In addition, in the coating removal method, for example, it is more suitable if the output energy density of the laser light is 1 [J / mm2] or more and 20 [J / mm2] or less.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to a method for removing a film and an apparatus for removing a film. [Background technology]

[0002] Conventionally, a method for removing the coating from an electric wire by irradiating it with laser light to expose the conductor covered by the coating is known. (Patent Document 1) [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2017-220634 [Overview of the project] [Problems that the invention aims to solve]

[0004] In this type of coating removal method, it would be beneficial to obtain a method that is less inconvenient, such as one that can remove the coating more reliably or one that requires less effort to remove the coating.

[0005] Therefore, one of the objectives of the present invention is, for example, to obtain a novel method and apparatus for removing coatings that have fewer drawbacks. [Means for solving the problem]

[0006] The present invention relates to a coating removal method, for example, a method for removing the insulating coating of an electric wire by irradiation with laser light, wherein the wavelength of the laser light is 533 nm or less.

[0007] Furthermore, in the aforementioned coating removal method, for example, the wavelength of the laser light is 350 nm or more and 533 nm or less.

[0008] In addition, in the film removal method, for example, the wavelength of the laser light is 400 [nm] or more and 500 [nm] or less.

[0009] In addition, in the film removal method, for example, the emission energy density of the laser light is 1 [J / mm or more and 20 [J / mm 2 or less.

[0010] In addition, in the film removal method, for example, the emission energy density of the laser light is 3 [J / mm 2 or more and 13 [J / mm 2 or less. [[ID=IS]]

[0011] In addition, in the film removal method, for example, the spot of the laser light is scanned and irradiated.

[0012] In addition, in the film removal method, for example, the spot diameter of the laser light is 200 [μm] or more. <000D070>

[0013] In addition, in the film removal method, for example, the laser light is a continuous wave.

Advantages of the Invention

[0014] According to the present invention, for example, a novel film removal method and a film removal device with fewer inconveniences can be obtained. [[ID=S7]]

Brief Description of the Drawings

[0015] [Figure 1] FIG. 1 is an exemplary and schematic perspective view of a wire from which a film is removed by the film removal method of the embodiment. [Figure 2] FIG. 2 is an exemplary schematic view of the film removal system of the embodiment. [Figure 3] [[ID=k9]]FIG. 3 is a flowchart showing the film removal method of the embodiment. [[ID=5I]] [Figure 4] [[ID=SZ]]FIG. 4 is a graph showing the light absorption rate of the synthetic resin material with respect to the wavelength of the laser light to be irradiated.

Best Mode for Carrying Out the Invention

[0016] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by such configurations, are examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

[0017] In this specification, ordinal numbers are given for convenience in distinguishing parts, sites, processes, etc., and do not indicate priorities or orders.

[0018] Also, in each figure, the X direction is represented by arrow X, the Y direction is represented by arrow Y, and the Z direction is represented by arrow Z. The X direction, Y direction, and Z direction intersect with each other and are orthogonal to each other. Note that the X direction may also be referred to as the longitudinal direction or the extending direction, the Y direction may also be referred to as the short-side direction or the width direction, and the Z direction may also be referred to as the thickness direction.

[0019] [Embodiment] FIG. 1 is a perspective view of a wire 10 from which a film 12 is removed by the film removal method of the present embodiment. As shown in FIG. 1, the wire 10 is, for example, a flat wire having a flat rectangular cross-section. The wire 10 has a strip-shaped and plate-shaped conductor 11 and a film 12 surrounding the periphery of the conductor 11.

[0020] The conductor 11 is made of, for example, a copper-based material such as oxygen-free copper or a copper alloy. Also, the film 12 is made of, for example, a synthetic resin material such as polyimide, polyamideimide, or polyetheretherketone.

[0021] As shown in FIG. 1, in order to electrically connect the conductor 11 to another conductor, the film 12 is removed over a predetermined section in the longitudinal direction from the end of the conductor 11. Note that the position where the film 12 is removed is not limited to the end of the wire 10.

[0022] The coating 12 is removed by irradiating it with laser light. When removing the coating 12, for example, the spot of the laser light is scanned on the coating 12 as shown by the dashed arrow in Figure 1. The scanning direction and number of scans are not limited to those shown in Figure 1. In addition, the coating 12 can be removed from surfaces other than those shown in Figure 1 in the same way. Furthermore, the electric wire 10 is not limited to a flat wire, and its cross-sectional shape is not limited to a rectangular shape.

[0023] [Covering system and coating removal method] Figure 2 is a schematic diagram of the coating removal system 100. As shown in Figure 2, the coating removal system 100 comprises a laser device 110, an optical head 120, and an optical fiber 130 connecting the laser device 110 and the optical head 120.

[0024] The laser device 110 is configured to output laser light with a power of, for example, several tens to several thousand watts. For example, the laser device 110 may be configured to include multiple semiconductor laser elements internally, and to output multimode laser light with a power of several tens to several thousand watts as the total output of these multiple semiconductor laser elements. The laser device 110 may also be equipped with various laser light sources such as fiber lasers, YAG lasers, and disk lasers.

[0025] The optical fiber 130 guides the laser light output from the laser device 110 to the optical head 120.

[0026] The optical head 120 is an optical device that emits laser light, which is input from the laser device 110 via the optical fiber 130, toward the electric wire 10. The optical head 120 may also be referred to as the emission unit.

[0027] The optical head 120 includes a collimating lens 121 and a focusing lens 122. The collimating lens 121 is an optical system for making the input laser light parallel. The focusing lens 122 is an optical system for focusing the parallelized laser light and irradiating the electric wire 10. The optical head 120 emits the laser light in the opposite direction to the Z direction. The laser light L emitted from the optical head 120 is irradiated onto the coating 12 of the electric wire 10.

[0028] The coating removal system 100 is configured to allow the relative position between the optical head 120 and the electric wire 10, i.e., the holding member (not shown) that holds the electric wire 10, to be changed. This moves the irradiation position of the laser beam on the surface of the coating 12 of the electric wire 10. As a result, the spot of the laser beam L, i.e., the irradiation area, is swept across the surface of the coating 12.

[0029] The relative movement between the optical head 120 and the electric wire 10 is achieved by a movement mechanism (not shown). The movement mechanism is configured to allow movement of the optical head 120 alone, the electric wire 10 (holding member) alone, or both the optical head 120 and the electric wire 10. In this embodiment, the optical head 120 and the electric wire 10 move relative to each other in the X and Y directions.

[0030] The swept laser beam L is preferably continuous light. However, it is not limited to this, and the laser beam L may also be pulsed light with a relatively high intermittent frequency.

[0031] Figure 3 is a flowchart illustrating the coating removal method of an embodiment. As shown in Figure 3, in this embodiment, first, the electric wire 10 to be processed is prepared (S1, first step), and then the coating 12 of the electric wire 10 is removed by irradiating the coating 12 with laser light L, exposing the conductor 11 covered by the coating 12 (S2, second step). If the electric wire 10 is a flat rectangular wire, in the first step S1, the irradiation surface (peeling surface) of the electric wire 10 is switched and set. In the first step S1, the electric wire 10 is set so that the surface (outer surface) of the coating 12 to be removed faces the Z direction.

[0032] [Wavelength and light absorption rate] Here, we will explain the light absorption rate of synthetic resin materials. Figure 4 is a graph showing the light absorption rate of synthetic resin materials as a function of the wavelength of the irradiated laser light L. In the graph in Figure 4, the horizontal axis is wavelength, and the vertical axis is absorption rate. As an example, Figure 4 shows the relationship between wavelength and absorption rate for polyimide as a synthetic resin material.

[0033] Although the properties differ slightly depending on the material, it can be understood that, for synthetic resin materials, using blue or green laser light L results in a higher energy absorption rate than using general infrared (IR) laser light L. When the absorption rate is high, for example, it becomes possible to remove the coating 12 more efficiently by irradiation with laser light L. From this perspective, the inventors conducted the following evaluations 1 and 2 to confirm the usefulness of removing the coating 12 by irradiation with laser light of 533 nm or less, which has a high absorption rate for synthetic resin materials.

[0034] [Evaluation Results] [Rating 1] The inventors evaluated the coating removal method using the coating removal system 100 for a total of 12 samples (1-1 to 1-12) in which the wavelength of the laser light emitted from the laser device 110, the output power of the laser light emitted from the laser device 110, the scanning speed of the laser light spot L on the coating 12, and the spot diameter (beam diameter) were varied. The evaluation results (experimental results) are shown in Table 1. [Table 1]

[0035] Evaluation 1 assessed three items: coating persistence, surface flatness, and mass loss. A comprehensive evaluation was then conducted based on these three items. The evaluation of the three items was divided into three ranks: "○" (good), "△" (acceptable), and "×" (unacceptable). The comprehensive evaluation was further divided into four ranks, with "◎" (excellent). In Table 1, "UM" means "unmeasurable."

[0036] Regarding the film residue, evaluation was performed based on the electrical resistance (contact resistance) between the film removal site (exposed site) and another conductor that was in close contact with the film removal site. This is in accordance with the phenomenon that the electrical resistance between the film removal site and another conductor decreases due to the remaining film at the film removal site.

[0037] The surface flatness was evaluated by the arithmetic mean roughness (Ra), which is the surface roughness defined in JIS B 0601 - 2001.

[0038] The mass loss was calculated as the ratio of the difference (decrease) in the mass of the electric wire 10 before and after the film peeling treatment to the mass of the original electric wire 10. s

[0039] In addition, the comprehensive evaluation was carried out based on the weighted evaluation of three items: film residue, surface flatness, and mass loss. s

[0040] (Wavelength) In Evaluation 1, for Samples 1 - 1 to 1 - 7 with a comprehensive evaluation of good or excellent, the wavelength was 450 [nm] or 532 [nm]. In contrast, for the case where the wavelength was 1070 [nm] (Samples 1 - 11, 1 - 12), good results were not obtained in the comprehensive evaluation. [[ID=二十二]]

[0041] (Energy density) In Evaluation 1, for Samples 1 - 1 to 1 - 7 with a comprehensive evaluation of good or excellent, the energy density was 3.33 [J / mm 2 or more and 20.0 [J / mm 2 or less. In contrast, for the case where the energy density was 0.75 [J / mm 2 (Sample 1 - 9), 33.3 [J / mm 2 (Sample 1 - 8), 5o.o [J / mm 2 (Sample 1 - 10), and 100.0 [J / mm 2 (Sample 1 - 12), good results were not obtained in the comprehensive evaluation.

[0042] (Spot diameter) In Evaluation 1, for samples 1-1 to 1-5, which received an overall excellent rating, the spot diameter ranged from 230 [μm] to 400 [μm].

[0043] [Rating 2] Next, the inventors evaluated the film removal method using the film removal system 100 for a total of six samples (2-1 to 2-6) in which the wavelength of the laser light emitted from the laser device 110, the output power of the laser light emitted from the laser device 110, the irradiation time of the laser light, and the spot diameter (beam diameter) were varied. The evaluation results (experimental results) are shown in Table 2. [Table 2]

[0044] In Evaluation 2, three items were evaluated: joint void ratio, required time, and joint strength. A comprehensive evaluation was then conducted based on these three items. In Evaluation 2, the three items were also categorized into three ranks: "○" (good), "△" (acceptable), and "×" (unacceptable). The comprehensive evaluation was further categorized into four ranks, with "◎" (excellent) added to the three.

[0045] The void ratio of the joint is the volumetric void ratio at the joint formed when the coating removal area and other conductors are joined together by a joining process under predetermined conditions. A higher void ratio at the joint indicates a larger joining area and therefore a higher quality joint.

[0046] The required time is the time taken to remove the coating from a predetermined area.

[0047] The joint strength is the tensile strength (peel strength) of the joint where the coating removal area and other conductors are joined by a bonding treatment under predetermined conditions.

[0048] Furthermore, the overall evaluation was conducted based on a weighted assessment of three items: joint void ratio, required time, and joint strength.

[0049] (wavelength) In Evaluation 2, samples 2-1 to 2-4, which received a good or excellent overall evaluation, had wavelengths of 450 nm or 532 nm. In contrast, samples with a wavelength of 1070 nm (samples 2-5 and 2-6) did not yield favorable results in the overall evaluation.

[0050] (Energy density) In Evaluation 2, for samples 2-1 to 2-4, which received an overall evaluation of Good or Excellent, the energy density was 4.44 [J / mm²]. 2 ] or 6.67[J / mm 2 ]. In contrast, the energy density was 20.0 [J / mm²]. 2 ] or 13.3[J / mm 2 In the case of [ ] (Samples 2-5, 2-6), a favorable result was not obtained in the overall evaluation. However, this is thought to be due to the effect of the wavelength being 1070 [nm].

[0051] (Spot diameter) In Evaluation 2, for samples 2-1 to 2-4, which received an overall evaluation of Good or Excellent, the spot diameter was 300 [μm].

[0052] As explained above, the inventors' research, including the results of evaluations 1 and 2, has revealed that the wavelength of the laser light emitted by the laser device 110 is preferably 533 nm or less, more preferably 350 nm or more and 533 nm or less, and even more preferably 400 nm or more and 500 nm or less.

[0053] Furthermore, based on the inventors' research, including the results of evaluations 1 and 2 above, the energy density of the laser light emitted by the laser device 110 is 1 [J / mm²]. 2 ] or more and 20[J / mm 2 Preferably, it is 3[J / mm²] or less. 2 ] or more and 13[J / mm 2It was found that it is even more preferable if the value is less than or equal to ]. The preferred range of energy density was determined within a preferred range of wavelength.

[0054] Furthermore, the inventors' research, including the results of evaluations 1 and 2 above, revealed that a spot diameter of 200 μm or more for the laser beam L on the coating 12 is preferable. The preferred range for the spot diameter was determined within a preferred range for the wavelength.

[0055] Although embodiments of the present invention have been illustrated above, these embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, each configuration, shape, and other specifications (structure, type, orientation, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate. [Explanation of Symbols]

[0056] 10...Electric wire 11...Conductor 12… Coating 100… Film removal system 110…Laser device 120…Optical head 121...Collimating lenses 122... Focusing lens 130… Fiber optic L... Laser light S1…first process S2…Second process X…direction Y... Direction Z…direction

Claims

1. A method for removing coatings made of synthetic resin material that covers a conductor made of copper-based material in an electric wire by irradiation with continuous laser light, The laser light is blue laser light, The irradiation energy density of the laser light is 3.33 [J / mm²]. ２ ] or more and 12.5 [J / mm ２ ] The following applies: The spot diameter of the laser beam is set to be 230 [μm] or more and 400 [μm] or less. The laser beam is scanned by the relative movement of the laser beam and the wire, By removing the coating with a laser beam scanning speed of 100 mm / s or more and 500 mm / s or less, The electrical resistance between the surface of the conductor from which the coating has been removed and another conductor in close contact with that surface becomes 0 [Ω]. The arithmetic mean roughness Ra, which is the surface roughness of the conductor surface after the coating has been removed, as defined in JIS B 0601-2001, is 1 or more and 3.1 or less, A method for removing a coating, wherein the mass loss of the conductor is 0.5% or more and 1.4% or less.

2. A coating removal device that removes a coating made of synthetic resin material covering a conductor made of copper-based material in an electric wire by irradiation with continuous laser light, A laser device that emits laser light, An optical head that emits the laser light output by the laser device toward the coating covering the conductor, Equipped with, The laser light is blue laser light, The irradiation energy density of the laser light is 3.33 [J / mm²]. ２ ] or more and 12.5 [J / mm ２ ] The following applies: The spot diameter of the laser beam is set to be 230 [μm] or more and 400 [μm] or less. The laser beam is scanned by the relative movement of the laser beam and the wire, By removing the coating with a laser beam scanning speed of 100 mm / s or more and 500 mm / s or less, The electrical resistance between the surface of the conductor from which the coating has been removed and another conductor in close contact with that surface becomes 0 [Ω]. The arithmetic mean roughness Ra, which is the surface roughness of the conductor surface after the coating has been removed, as defined in JIS B 0601-2001, is 1 or more and 3.1 or less, A coating removal device wherein the mass loss of the conductor is 0.5% or more and 1.4% or less.

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