Composite manufacturing method, composite manufacturing device, and composite

Abstract

To provide a complex manufacturing method that can suppress a joining defect, even if intensity of emitted laser beams on joined surfaces is uneven.SOLUTION: A complex manufacturing method according to an embodiment includes a surface processing step and a joining step. In the surface processing step, surface processing for varying laser beam absorptivity is performed to a first surface of a first member. In the joining step, the first surface is joined to a second surface, by emitting a laser beam toward the first surface from a surface at the opposite side of the second surface of a second member, while contacting the second surface of the second member with the first surface subjected to surface processing. The first surface has a first portion at which intensity of the laser beam emitted in the joining step is first intensity and a second portion at which intensity of the laser beam emitted in the joining step is second intensity smaller than the first intensity. In the surface processing step, surface processing is performed so that second absorptivity which is laser beam absorptivity in the second portion is larger than first absorptivity which is laser beam absorptivity in the first portion.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a composite manufacturing method, a composite manufacturing apparatus, and a composite. [Background technology]

[0002] There is a method for manufacturing a composite by joining metal and resin components by irradiating the joining surfaces with laser light. The intensity of the laser light tends to decrease as the distance from the center of the laser beam increases. Therefore, the degree of temperature rise differs between the center of the joining surface close to the beam center and the edge away from the beam center, which can cause defects in the joining. [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-179920 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a composite manufacturing method, a composite manufacturing apparatus, and a composite that can suppress bonding defects even when the intensity of the irradiated laser light is non-uniform on the bonding surface. [Means for solving the problem]

[0005] A composite manufacturing method according to an embodiment is a method for manufacturing a composite in which a first metal member and a second laser beam-transmitting resin member are joined together, and includes a surface treatment step and a joining step. In the surface treatment step, a first surface of the first member is subjected to a surface treatment process to change the absorptance of the laser beam. In the joining step, a second surface of the second member is brought into contact with the surface-treated first surface, and the laser beam is irradiated from a surface of the second member opposite the second surface toward the first surface without scanning, thereby joining the first surface and the second surface. The first surface has a first portion to which the laser beam is irradiated in the joining step with a first intensity, and a second portion to which the laser beam is irradiated in the joining step with a second intensity that is lower than the first intensity. In the surface treatment step, the surface treatment step is performed so that a second absorptance, which is the absorptance of the laser beam in the second portion, is greater than a first absorptance, which is the absorptance of the laser beam in the first portion. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is an explanatory diagram schematically illustrating a composite manufacturing apparatus according to an embodiment. [Figure 2] 1 is a flowchart illustrating an example of a composite manufacturing method according to an embodiment. [Figure 3] 10A and 10B are plan views schematically illustrating an example of the intensity distribution of laser light in a joining step of the composite manufacturing method according to the embodiment. [Figure 4] 4(a) and 4(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment process in the method for producing a composite according to the embodiment. [Figure 5] 5(a) and 5(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment step of the composite manufacturing method according to the embodiment. [Figure 6] 6(a) and 6(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment step of the composite manufacturing method according to the embodiment. [Figure 7]7(a) and 7(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment step of the composite manufacturing method according to the embodiment. [Figure 8] 8(a) to 8(c) are graphs showing the relationship between the absorptance of the laser light and the temperature of the second member during irradiation with the laser light. [Figure 9] FIG. 1 is a perspective view schematically illustrating a composite according to an embodiment. [Figure 10] 10(a) to 10(c) are cross-sectional views that schematically show the composite according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In this specification and in each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0008] FIG. 1 is an explanatory diagram that schematically shows a composite manufacturing apparatus according to an embodiment. The composite manufacturing apparatus 100 according to the embodiment is an apparatus for manufacturing a composite 30 in which a first member 10 and a second member 20 are joined together.

[0009] The first member 10 is made of metal. The first member 10 includes, for example, at least one of iron and copper. The second member 20 is made of resin. The second member 20 is made of, for example, a resin that is transmissive to laser light. The second member 20 is made of, for example, a resin that is transmissive to laser light with a wavelength of 800 nm or more and 2000 nm or less. The second member 20 includes, for example, at least one of epoxy resin and acrylic resin.

[0010] As shown in FIG. 1, the composite manufacturing apparatus 100 according to the embodiment includes a surface treatment section 110 and a bonding section 120.

[0011] The surface treatment section 110 performs surface treatment processing to change the absorptance of laser light on the first surface 11 of the first member 10. The surface treatment section 110 has, for example, a first laser irradiation section 111 and a first placement section 112. In the surface treatment section 110, for example, the first laser irradiation section 111 irradiates the first surface 11 of the first member 10 placed on the first placement section 112 with laser light, thereby performing surface treatment processing.

[0012] The first laser irradiation unit 111 uses, for example, a pulsed laser that oscillates a pulsed output at a constant repetition frequency (pulse width). When a pulsed laser is used in the first laser irradiation unit 111, the pulse width of the pulsed laser light is, for example, nanoseconds or less. When a pulsed laser is used in the first laser irradiation unit 111, the wavelength of the pulsed laser light is, for example, 300 nm or more and 1000 nm or less. The surface treatment process is not limited to irradiation with pulsed laser light. The surface treatment process will be described later.

[0013] The joining unit 120 joins the first surface 11 of the first member 10, which has been subjected to surface treatment, and the second surface 21 of the second member 20. The joining unit 120 has, for example, a second laser irradiation unit 121 and a second placement unit 122. In the joining unit 120, the first surface 11 of the first member 10 is placed on the second placement unit 122, and the second surface 21 of the second member 20 is brought into contact with the first surface 11, and the second laser irradiation unit 121 irradiates the first surface 11 of the first member 10 with laser light, thereby joining the first surface 11 and the second surface 21.

[0014] At this time, the second laser irradiation unit 121 irradiates the laser light toward the surface 22 of the second member 20 opposite to the second surface 21. The laser light irradiated onto the surface 22 of the second member 20 passes through the inside of the second member 20 and is irradiated onto the first surface 11 of the first member 10. When the laser light is irradiated onto the first surface 11, the first surface 11 is heated by the laser light, and the second surface 21 of the second member 20 in contact with the first surface 11 melts, bonding the first surface 11 and the second surface 21 together. The second laser irradiation unit 121 irradiates the laser light without scanning.

[0015] The second laser irradiation unit 121 may be, for example, a CW (Continuous Wave) laser that continuously oscillates at a constant output. A pulsed laser may be used for the second laser irradiation unit 121. The wavelength of the laser light irradiated from the second laser irradiation unit 121 is selected based on the absorption wavelength of the first member 10. When the first member 10 contains iron, the wavelength of the laser light irradiated from the second laser irradiation unit 121 is, for example, not less than 800 nm and not more than 2000 nm. When the first member 10 contains copper, the wavelength of the laser light irradiated from the second laser irradiation unit 121 is, for example, not less than 500 nm and not more than 2000 nm.

[0016] A composite manufacturing method using the composite manufacturing apparatus 100 according to the embodiment will be described below. FIG. 2 is a flowchart illustrating an example of a method for producing a composite according to the embodiment. As shown in FIG. 2, the method for manufacturing a composite according to the embodiment includes a surface treatment step and a bonding step.

[0017] In the composite manufacturing method according to the embodiment, first, a surface treatment step is performed in the surface treatment section 110 (step S101). In the surface treatment step, a surface treatment process is performed on the first surface 11 of the first member 10 to change the absorptance of laser light. The surface treatment step will be described later.

[0018] In the composite manufacturing method according to the embodiment, next, a joining step is performed in the above-mentioned joining section 120 (step S102). In the joining step, the first surface 11 of the first member 10, which has been subjected to surface treatment, and the second surface 21 of the second member 20 are joined together. In the joining step, with the second surface 21 in contact with the first surface 11, a laser beam is irradiated from a surface 22 of the second member 20 opposite the second surface 21 toward the first surface 11 of the first member 10 without scanning, thereby joining the first surface 11 and the second surface 21 together.

[0019] FIG. 3 is a plan view schematically illustrating an example of the intensity distribution of laser light in the joining step of the composite manufacturing method according to the embodiment. In FIG. 3, areas where the laser light intensity is high are indicated by dark colors, and areas where the laser light intensity is low are indicated by light colors. As described above, in the joining process, the laser beam is irradiated onto the entire area to be joined without scanning. The intensity of the laser beam tends to decrease with increasing distance from the beam center BC of the laser beam. Therefore, as shown in FIG. 3, a difference in the intensity of the laser beam irradiated onto the first surface 11 tends to occur between the first portion 11a (center portion) close to the beam center BC and the second portion 11b (edge ​​portion) away from the beam center BC.

[0020] The first surface 11 has a first portion 11a and a second portion 11b. When the intensity of the laser light irradiated onto the first portion 11a in the joining process is defined as a first intensity and the intensity of the laser light irradiated onto the second portion 11b in the joining process is defined as a second intensity, the second intensity is smaller than the first intensity.

[0021] In the second portion 11b, to which the intensity of the laser light irradiated in the joining step is low, the temperature of the first member 10 is less likely to rise than in the first portion 11a, to which the intensity of the laser light irradiated in the joining step is high. Therefore, in the portion of the second member 20 that contacts the second portion 11b, the resin is less likely to melt than in the portion that contacts the first portion 11a, and as a result, the joining strength is likely to be weaker.

[0022] Therefore, in the composite manufacturing method according to the embodiment, in the surface treatment step, surface treatment is performed so that the laser light absorption rate in the second portion 11b is greater than the laser light absorption rate in the first portion 11a. The "laser light" here refers to the laser light irradiated in the joining step. Hereinafter, the laser light absorption rate in the first portion 11a will be referred to as the "first absorption rate," and the laser light absorption rate in the second portion 11b will be referred to as the "second absorption rate."

[0023] In this way, by performing the surface treatment so that the second absorptance is greater than the first absorptance, it is possible to prevent a temperature difference from occurring between the second portion 11b and the first portion 11a, even if the intensity of the laser light irradiated onto the second portion 11b is lower than the intensity of the laser light irradiated onto the first portion 11a. This makes it possible to make the temperature within the first surface 11 more uniform during the bonding process, thereby preventing variations in the bonding strength within the first surface 11. Therefore, even if the intensity of the irradiated laser light is non-uniform on the bonding surface (first surface 11), it is possible to prevent bonding defects.

[0024] In the surface treatment step, for example, the second portion 11b is subjected to a surface treatment process to increase the absorptance of the laser beam, so that the second absorptance is greater than the first absorptance. Alternatively, in the surface treatment step, for example, both the first portion 11a and the second portion 11b are subjected to a surface treatment process to increase the absorptance of the laser beam, so that the degree of processing in the second portion 11b is greater than the degree of processing in the first portion 11a, so that the second absorptance is greater than the first absorptance.

[0025] One method for increasing the absorption rate of laser light is to increase the surface roughness of the target part. Specifically, one such method is to irradiate the target part with pulsed laser light. Other methods for increasing the absorption rate of laser light include physical methods such as rubbing the target part with sandpaper or chemical methods such as applying a chemical to the target part.

[0026] In addition, in the surface treatment step, for example, the first portion 11a may be subjected to a surface treatment process to reduce the absorptance of the laser beam, so that the second absorptance is greater than the first absorptance. Alternatively, in the surface treatment step, for example, both the first portion 11a and the second portion 11b may be subjected to a surface treatment process to reduce the absorptance of the laser beam, so that the degree of processing in the first portion 11a is greater than the degree of processing in the second portion 11b, so that the second absorptance is greater than the first absorptance.

[0027] A method for reducing the laser light absorption rate includes, for example, increasing the laser light reflectance of the target portion, such as irradiating the target portion with laser light to melt the surface.

[0028] The method of increasing the laser light absorptance can more easily make the second absorptance greater than the first absorptance, compared to, for example, a method of decreasing the laser light absorptance. Furthermore, the method of increasing the laser light absorptance by irradiating pulsed laser light makes it easier to perform surface treatment in a desired range with a desired processing degree, compared to other methods. Furthermore, the method of increasing the laser light absorptance by irradiating pulsed laser light makes it easier to perform surface treatment in which the laser light absorptance continuously increases from the first portion 11a to the second portion 11b, compared to other methods.

[0029] The difference between the first absorptance and the second absorptance is determined based on, for example, the intensity distribution of the laser light irradiated on the first surface 11 in the bonding process. For example, when there is a large difference between the intensity of the laser light at a position (first portion 11a) close to the beam center BC of the laser light and the intensity of the laser light at a position (second portion 11b) away from the beam center BC of the laser light, it is preferable to increase the difference between the first absorptance and the second absorptance. On the other hand, when there is a small difference between the intensity of the laser light at a position (first portion 11a) close to the beam center BC of the laser light and the intensity of the laser light at a position (second portion 11b) away from the beam center BC of the laser light, it is preferable to decrease the difference between the first absorptance and the second absorptance.

[0030] An example of the surface treatment will be described below. In the following, an example will be described in which the second portion 11b or both the first portion 11a and the second portion 11b are subjected to a surface treatment process to increase the absorptance of laser light.

[0031] 4(a) and 4(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment process in the method for producing a composite according to the embodiment. FIG. 4(b) is a cross-sectional view taken along line A1-A2 shown in FIG. 4(a). 4(a) and 4(b), in this example, both the first portion 11a and the second portion 11b are surface-treated, and the degree of processing in the second portion 11b is made higher than that in the first portion 11a, so that the second absorbency is greater than the first absorbency. The surface roughness of the second portion 11b is greater than that of the first portion 11a.

[0032] The surface roughness is expressed, for example, by the particle size and density of the particulate nanostructures formed by the surface treatment process. The particle size of the nanostructures in the second portion 11b is, for example, smaller than the particle size of the nanostructures in the first portion 11a. The density of the nanostructures in the second portion 11b is, for example, greater than the density of the nanostructures in the first portion 11a.

[0033] 5(a) and 5(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment step of the composite manufacturing method according to the embodiment. FIG. 5(b) is a cross-sectional view taken along line B1-B2 shown in FIG. 5(a). 5(a) and 5(b), in this example, the second portion 11b is subjected to a surface treatment process to increase the laser light absorption rate, while the first portion 11a is not subjected to a surface treatment process, so that the second absorption rate is greater than the first absorption rate. The surface roughness of the second portion 11b is greater than the surface roughness of the first portion 11a.

[0034] The processing conditions in the surface treatment step are determined based on, for example, at least one of the thermal conductivity of the first member 10, the laser light absorption rate of the first surface 11, and the melting temperature of the second member 20. The "processing conditions" here include, for example, whether or not to perform surface treatment on the first portion 11a, and the degree of surface treatment (processing degree) on the first portion 11a and the second portion 11b.

[0035] For example, if the thermal conductivity of the first member 10 is high, if the laser light absorption rate of the first surface 11 before the surface treatment is low, or if the melting temperature of the second member 20 is high, it is preferable to also perform surface treatment on the first portion 11a. In such cases, it is preferable to increase the degree of surface treatment on the first portion 11a and the second portion 11b.

[0036] On the other hand, for example, if the thermal conductivity of the first member 10 is low, if the laser light absorption rate of the first surface 11 before surface treatment is high, or if the melting temperature of the second member 20 is low, the first portion 11a does not need to be surface treated. In such cases, it is preferable to reduce the degree of surface treatment on the second portion 11b.

[0037] One possible method for making the degree of temperature rise at the joining surface uniform is to make uniform the intensity distribution of the laser light irradiated from the second laser irradiation unit 121. However, with such a method, it is difficult to select appropriate conditions depending on the types of the first member 10 and the second member 20, the type of laser used for surface treatment processing, the type of laser used for joining, and the like.

[0038] In contrast, in the method of varying the laser light absorption rate within the first surface 11 by surface treatment processing as in the embodiment, appropriate conditions can be selected depending on the types of the first member 10 and the second member 20, the type of laser used for surface treatment processing, the type of laser used for joining, etc. This makes it possible to more reliably suppress joining defects even if the intensity of the irradiated laser light is non-uniform on the joining surface (first surface 11).

[0039] 6(a) and 6(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment step of the composite manufacturing method according to the embodiment. FIG. 6(b) is a cross-sectional view taken along line C1-C2 shown in FIG. 6(a). 6(a) and 6(b), in this example, the surface treatment is performed so that the laser light absorptance increases continuously from the first portion 11a to the second portion 11b. In other words, the laser light absorptance gradually increases from the first portion 11a to the second portion 11b. The surface roughness of the first surface 11 increases continuously from the first portion 11a to the second portion 11b (i.e., from the center to the edge).

[0040] For example, by changing the intensity and irradiation time of the pulsed laser light while scanning from the center of the first portion 11a toward the end of the first surface 11, surface treatment can be performed so that the surface roughness increases continuously from the first portion 11a toward the second portion 11b.

[0041] 7(a) and 7(b) are a plan view and a cross-sectional view that schematically show an example of the first surface after the surface treatment step of the composite manufacturing method according to the embodiment. FIG. 7(b) is a cross-sectional view taken along line D1-D2 shown in FIG. 7(a). 7(a) and 7(b), in this example, surface treatment is not performed on a portion of the first portion 11a and the second portion 11b. In this way, surface treatment does not need to be performed on the portion of the first surface 11 that is not joined to the second member 20. The first portion 11a and the second portion 11b may include a plurality of portions with different laser light absorptances.

[0042] The laser light absorptance of the portion not subjected to surface treatment is, for example, smaller than the first absorptance. In this case, the laser light absorptance of the portion of the first portion 11a subjected to surface treatment is regarded as the first absorptance, and the laser light absorptance of the portion of the second portion 11b subjected to surface treatment is regarded as the second absorptance.

[0043] 8(a) to 8(c) are graphs showing the relationship between the absorptance of the laser light and the temperature of the second member during irradiation with the laser light. 8(a) to 8(c), the distribution of the laser light absorptance on the first surface 11 of the first member 10 is represented by a solid line, and the temperature distribution at the corresponding position on the second member 20 when irradiated with the laser light in the joining process is represented by a dashed line. In addition, the beam center of the laser light is represented by a dashed line.

[0044] 8(a), when the laser light absorptance (second absorptance) in the second portion 11b is the same as the laser light absorptance (first absorptance) in the first portion 11a, when the laser light is irradiated in the joining step, the temperature of the portion of the second member 20 that contacts the second portion 11b will be lower than the temperature of the portion of the second member 20 that contacts the first portion 11a. Furthermore, the temperature difference between the portion of the second member 20 that contacts the second portion 11b and the portion of the second member 20 that contacts the first portion 11a is likely to be large. In other words, when no surface treatment is performed on the first surface 11 or when surface treatment is performed uniformly over the entire surface of the first surface 11, the temperature of the second member 20 is likely to be non-uniform within the surface.

[0045] 8(b) and 8(c), when the surface treatment is performed so that the laser light absorptance (second absorptance) in the second portion 11b is greater than the laser light absorptance (first absorptance) in the first portion 11a, the difference in temperature between the portion of the second member 20 that contacts the second portion 11b and the portion of the second member 20 that contacts the first portion 11a is likely to be smaller than when the laser light absorptance (second absorptance) in the second portion 11b is the same as the laser light absorptance (first absorptance) in the first portion 11a. In other words, the temperature of the second member 20 is likely to be uniform within the plane.

[0046] Furthermore, as shown in FIG. 8(c), by performing surface treatment so that the surface roughness increases continuously from the first portion 11a to the second portion 11b, the temperature of the second member 20 tends to become more uniform within the surface.

[0047] In the above example, the first surface 11 includes the first portion 11a and the second portion 11b. However, the first surface 11 may further include a third portion located more radially outward than the second portion 11b. The third portion, for example, surrounds the outside of the second portion 11b. In this case, the laser light absorptance (third absorptance) in the third portion is greater than the laser light absorptance (second absorptance) in the second portion 11b. In this case, the surface roughness of the third portion is greater than the surface roughness of the second portion 11b. The surface roughness of the third portion is constant within the third portion. The laser light absorptance of the first surface 11 may continuously increase from the second portion 11b toward the third portion (i.e., from the center toward the edge). The surface roughness of the first surface 11 may continuously increase from the second portion 11b toward the third portion (i.e., from the center toward the edge). The third portion may also include multiple portions with different surface roughnesses. The first surface 11 may also have one or more portions located further outward than the third portion.

[0048] The composite manufacturing apparatus 100 according to the embodiment and the composite 30 manufactured by the composite manufacturing method according to the embodiment will be described below. FIG. 9 is a perspective view that schematically illustrates a composite according to an embodiment. 10(a) to 10(c) are cross-sectional views that schematically show the composite according to the embodiment. 10(a) to 10(c) are examples of cross-sectional views taken along line E1-E2 shown in FIG. 9 and 10(a) to 10(c), a composite 30 according to the embodiment includes a first member 10 and a second member 20. The first member 10 and the second member 20 are joined via a first surface 11 and a second surface 21.

[0049] The first surface 11 has a first region 11x and a second region 11y. The first region 11x corresponds to the first portion 11a after bonding. The second region 11y corresponds to the second portion 11b after bonding. The first region 11x includes, for example, the center CT of the first surface 11. The second region 11y is located, for example, closer to the outer periphery than the first region 11x. The second region 11y surrounds, for example, the outside of the first region 11x.

[0050] The surface roughness of at least a portion of the second region 11y is greater than the surface roughness of at least a portion of the first region 11x. The overall surface roughness of the second region 11y is greater than the overall surface roughness of the first region 11x, for example. The average value of the surface roughness of the second region 11y is greater than the average value of the surface roughness of the first region 11x, for example.

[0051] As shown in FIG. 10(a), the surface roughness of the first region 11x is, for example, constant within the first region 11x. The surface roughness of the second region 11y is, for example, constant within the second region 11y. That is, the first surface 11 has, for example, multiple regions with different surface roughnesses. For example, a composite 30 having a structure as shown in FIG. 10(a) can be manufactured by performing the surface treatment process shown in FIGS. 4(a) and 4(b) or the surface treatment process shown in FIGS. 5(a) and 5(b).

[0052] As shown in FIG. 10(b), the surface roughness of the first surface 11 may, for example, continuously increase from the first region 11x toward the second region 11y. In this case, the surface roughness of the first region 11x is, for example, not constant in the first region 11x. Also, in this case, the surface roughness of the second region 11y is, for example, not constant in the second region 11y. For example, by performing the surface treatment process shown in FIGS. 6(a) and 6(b), a composite 30 having a structure as shown in FIG. 10(b) can be manufactured.

[0053] As shown in FIG. 10(c), the surface roughness of the first region 11x may not be constant, for example, within the first region 11x. That is, the first region 11x may have multiple regions with different surface roughnesses. In addition, in this example, the surface roughness of the second region 11y is constant within the second region 11y, but the surface roughness of the second region 11y may not be constant within the second region 11y. That is, the second region 11y may have multiple regions with different surface roughnesses. For example, a composite 30 having a structure as shown in FIG. 10(c) can be manufactured by performing the surface treatment process shown in FIGS. 7(a) and 7(b).

[0054] The surface roughness of the first surface 11 is represented by, for example, the pitch (width), density, depth, etc. of the irregularities on the first surface 11 in the cross section of the composite 30. The pitch (width) of the irregularities in the second region 11y is smaller than the pitch (width) of the irregularities in the first region 11x, for example. The density of the irregularities in the second region 11y is greater than the density of the irregularities in the first region 11x, for example. The depth of the irregularities in the second region 11y is greater than the depth of the irregularities in the first region 11x, for example.

[0055] In this way, if the surface roughness of the second region 11y is greater than the surface roughness of the first region 11x, the composite 30 will have reduced defects in the bonding between the first member 10 and the second member 20.

[0056] In the above example, the first surface 11 includes the first region 11x and the second region 11y. However, the first surface 11 may further include a third region located on the outer periphery side of the second region 11y. The third region, for example, surrounds the outside of the second region 11y. The third region corresponds to a third portion after bonding. In this case, the surface roughness of the third region is, for example, greater than the surface roughness of the second region 11y. The surface roughness of the third region is, for example, constant within the third region. The surface roughness of the first surface 11 may continuously increase from the second region 11y toward the third region (i.e., from the center toward the edge). The third region may also include multiple regions with different surface roughnesses. The first surface 11 may also include one or more regions located further outer periphery than the third region.

[0057] Furthermore, in the above example, the case where the beam center BC of the laser light irradiated in the joining process coincides with the center CT of the first member 10 is described as an example, but the beam center BC and the center CT of the first member 10 do not have to coincide.

[0058] Embodiments may include the following features.

[0059] (Configuration 1) A method for manufacturing a composite in which a first member made of metal and a second member made of resin that is transmissive to laser light are joined, comprising the steps of: a surface treatment step of performing a surface treatment process on a first surface of the first member to change the absorptance of the laser light; a joining step of joining the first surface and the second surface by irradiating the laser light from a surface of the second member opposite to the second surface toward the first surface without scanning, while bringing the second surface of the second member into contact with the first surface that has been subjected to the surface treatment; Equipped with the first surface has a first portion to which the intensity of the laser light irradiated in the joining step is a first intensity, and a second portion to which the intensity of the laser light irradiated in the joining step is a second intensity that is lower than the first intensity, a surface treatment process is performed such that a second absorptance, which is the absorptance of the laser light in the second portion, is greater than a first absorptance, which is the absorptance of the laser light in the first portion.

[0060] (Configuration 2) 2. The method for producing a composite according to claim 1, wherein in the surface treatment step, the second portion is irradiated with pulsed laser light to increase the absorption rate of the laser light in the second portion.

[0061] (Configuration 3) 3. The method for producing a composite according to claim 1, wherein in the surface treatment step, the surface treatment is performed so that the absorptance of the laser light increases continuously from the first portion toward the second portion.

[0062] (Configuration 4) 4. The composite manufacturing method according to any one of configurations 1 to 3, wherein in the surface treatment step, a difference between the first absorptance and the second absorptance is determined based on an intensity distribution on the first surface of the laser light irradiated in the joining step.

[0063] (Configuration 5) 5. The method for producing a composite according to any one of aspects 1 to 4, wherein processing conditions in the surface treatment step are determined based on at least one of the thermal conductivity of the first member, the absorptivity of the laser light on the first surface, and the melting temperature of the second member.

[0064] (Configuration 6) An apparatus for manufacturing a composite in which a first member made of metal and a second member made of resin that is transmissive to laser light are joined, a surface treatment section that performs surface treatment on a first surface of the first member to change the absorptance of the laser light; a joining portion that joins the first surface and the second surface by irradiating the laser light from a surface of the second member opposite to the second surface toward the first surface without scanning, while bringing the second surface of the second member into contact with the first surface that has been subjected to the surface treatment; Equipped with the first surface has a first portion where the intensity of the laser light irradiated at the joint is a first intensity, and a second portion where the intensity of the laser light irradiated at the joint is a second intensity that is smaller than the first intensity, The surface treatment unit performs the surface treatment so that a second absorptance, which is the absorptance of the laser light in the second portion, is greater than a first absorptance, which is the absorptance of the laser light in the first portion.

[0065] (Configuration 7) 7. The composite manufacturing apparatus according to claim 6, wherein the surface treatment section irradiates the second portion with pulsed laser light to increase the absorption rate of the laser light in the second portion.

[0066] (Configuration 8) 8. The composite manufacturing apparatus according to claim 6 or 7, wherein the surface treatment section performs the surface treatment so that the absorptance of the laser light increases continuously from the first portion toward the second portion.

[0067] (Configuration 9) The composite manufacturing apparatus of any one of configurations 6 to 8, wherein the difference between the first absorptance and the second absorptance is determined based on the intensity distribution on the first surface of the laser light irradiated at the joint.

[0068] (Configuration 10) 10. The composite manufacturing apparatus according to any one of configurations 6 to 9, wherein processing conditions in the surface treatment section are determined based on at least one of the thermal conductivity of the first member, the absorptance of the laser light on the first surface, and the melting temperature of the second member.

[0069] (Configuration 11) a first member made of metal and having a first surface; a second member made of resin and having a second surface; Equipped with the first surface and the second surface are joined together; the first surface has a first region and a second region; A composite, wherein a surface roughness of at least a portion of the second region is greater than a surface roughness of at least a portion of the first region.

[0070] (Configuration 12) 12. The composite of claim 11, wherein the surface roughness of the first surface increases continuously from the first region toward the second region.

[0071] As described above, according to the embodiments, it is possible to provide a composite manufacturing method, a composite manufacturing apparatus, and a composite that can suppress joining defects even when the intensity of the irradiated laser light is uneven on the joining surface.

[0072] While the present invention has been described above by way of example, it is not intended to limit the scope of the present invention. This novel embodiment may be embodied in various other forms, and various omissions, substitutions, modifications, etc. may be made without departing from the spirit of the invention. This embodiment and its modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the claims and their equivalents. [Explanation of symbols]

[0073] 10 First member 11 Page 1 11a Part 1 11b Part 2 11x 1st area 11y 2nd area 20 Second member 21 Side 2 22 sides 30 Complex 100 Composite manufacturing equipment 110 Surface treatment section 111 First laser irradiation unit 112 First placement section 120 Joint 121 Second laser irradiation unit 122 Second placement section BC beam center CT center

Claims

1. A method for manufacturing a composite in which a first member made of metal and a second member made of resin that is transmissive to laser light are joined together, the method comprising: a surface treatment step of performing a surface treatment process on a first surface of the first member to change the absorptance of the laser light; a joining step of joining the first surface and the second surface by irradiating the laser light from a surface of the second member opposite to the second surface toward the first surface without scanning, while bringing the second surface of the second member into contact with the first surface that has been subjected to the surface treatment; Equipped with the first surface has a first portion to which the intensity of the laser light irradiated in the joining step is a first intensity, and a second portion to which the intensity of the laser light irradiated in the joining step is a second intensity that is smaller than the first intensity, a surface treatment process is performed such that a second absorptance, which is the absorptance of the laser light in the second portion, is greater than a first absorptance, which is the absorptance of the laser light in the first portion.

2. The method for producing a composite according to claim 1 , wherein the surface treatment step includes irradiating the second portion with pulsed laser light to increase the absorption rate of the laser light in the second portion.

3. 3. The method for producing a composite according to claim 1, wherein the surface treatment step is performed so that the absorptance of the laser light increases continuously from the first portion toward the second portion.

4. 3. The composite manufacturing method according to claim 1, wherein in the surface treatment step, a difference between the first absorptance and the second absorptance is determined based on an intensity distribution on the first surface of the laser light irradiated in the joining step.

5. 3. The composite manufacturing method according to claim 1, wherein processing conditions in the surface treatment step are determined based on at least one of the thermal conductivity of the first member, the absorptance of the laser light at the first surface, and the melting temperature of the second member.

6. An apparatus for manufacturing a composite in which a first member made of metal and a second member made of resin that is transmissive to laser light are joined, a surface treatment section that performs a surface treatment process on a first surface of the first member to change the absorptance of the laser light; a joining portion that joins the first surface and the second surface by irradiating the laser light from a surface of the second member opposite to the second surface toward the first surface without scanning, while bringing the second surface of the second member into contact with the first surface that has been subjected to the surface treatment; Equipped with the first surface has a first portion where the intensity of the laser light irradiated at the joint is a first intensity, and a second portion where the intensity of the laser light irradiated at the joint is a second intensity that is smaller than the first intensity, The surface treatment unit performs the surface treatment so that a second absorptance, which is the absorptance of the laser light in the second portion, is greater than a first absorptance, which is the absorptance of the laser light in the first portion.

7. The composite manufacturing apparatus according to claim 6 , wherein the surface treatment section irradiates the second portion with pulsed laser light to increase the absorption rate of the laser light in the second portion.

8. 8. The composite manufacturing apparatus according to claim 6, wherein the surface treatment section performs the surface treatment so that the absorptance of the laser light increases continuously from the first portion toward the second portion.

9. 8. The composite manufacturing apparatus according to claim 6, wherein a difference between the first absorptance and the second absorptance is determined based on an intensity distribution on the first surface of the laser light irradiated at the joint.

10. 8. The composite manufacturing apparatus according to claim 6, wherein processing conditions in the surface treatment section are determined based on at least one of a thermal conductivity of the first member, an absorptance of the laser light by the first surface, and a melting temperature of the second member.

11. a first member made of metal and having a first surface; a second member made of resin and having a second surface; Equipped with the first surface and the second surface are joined together; the first surface has a first region and a second region; a surface roughness of at least a portion of the second region is greater than a surface roughness of at least a portion of the first region; The composite, wherein the surface roughness of the first surface increases continuously from the first region toward the second region.

Images