JP5941563B2 - Laser bonding apparatus and laser bonding method - Google Patents

Description

  The present invention relates to an apparatus and a method for heat-bonding resin and metal by laser light.

Thermoplastic resins are widely used in general industrial applications such as automobiles, electrical equipment, medical and biotechnology equipment because of their excellent processability and large degree of freedom in shape. There is no field where thermoplastic resins are not used. It is so popular that it is a familiar material. Due to the recent trend of CO ₂ emission restrictions and cost reduction, as the functionality of thermoplastic resins increases, replacement of metals is gradually being made, and thermosetting resins containing carbon fibers have also become widespread for metal replacement. It's getting on. However, thermoplastic resins and thermosetting resins generally tend to have lower heat resistant temperatures and mechanical strength than metals. In addition, generally used thermoplastic resins and thermosetting resins have weaknesses such as higher thermal expansion coefficient, easier deformation and decomposition, easier to dissolve in organic solvents, and more likely to swell due to moisture. Because there are many, it is difficult to completely replace it.

  In particular, due to the complexity of product structures in recent years, designs that make use of the characteristics of thermoplastic resins, thermosetting resins, and metals have been made, and their secondary processing techniques have become important. Among them, with the widespread use of semiconductor lasers, a method of joining a resin and a metal using laser light has been increasingly studied.

  Patent Document 1 describes a method of joining a resin and a metal by heating, in which the joining interface between the resin and the metal is heated to a certain temperature range and joined while cooling the opposite surface. Yes. Thus, it is described that sufficient bonding strength can be obtained.

  In Patent Document 2, it is possible to firmly bond even if the molded body does not transmit laser light by irradiating laser from the metal side in a state where the molded body made of a thermoplastic resin and the metal are overlapped. It is shown. It is also described that the surface treatment of the metal on the bonding surface side is effective for improving the bonding strength.

Japanese Unexamined Patent Publication No. 2010-46831 Japanese Unexamined Patent Publication No. 2008-21356

  The technique disclosed in Patent Document 1 has a complicated configuration and a system in which resin and metal are simultaneously cooled from the opposite side so that the temperature of the joint surface does not rise excessively when the resin and metal are heated to a certain temperature range and joined. It is difficult to save energy. In particular, the present technology describes an alternative to a spot welder configuration or a heating body in a roller shape and a method for joining plate-like products, but is applied when the shape of the joint surface is complicated and small. There is a problem that it is difficult.

  Further, although there is a disclosure of a heating method using laser light, it is incident light from the transparent resin side, and is not applicable in the case of a thermoplastic resin that is not transparent. As described above, in these configurations, there is a problem that it is difficult to apply when the joint surface has a complicated shape.

  In the technique disclosed in Patent Document 2, it is shown that laser irradiation is performed from the metal side, and laser light is simultaneously irradiated onto the bonding surface for heating, and the thermoplastic resin and the metal are bonded. The pressurizing method on the surface is not described. Further, it is described that the bonding surface improves the bonding strength by causing the thermoplastic resin to reach the thermal decomposition temperature and generating a large amount of bubbles. However, bubbles on the joint surface can be a weak point for products that require long-term reliability. In particular, there is a problem that it is difficult to apply to products that prioritize ensuring airtightness.

In order to solve the above problems, the laser bonding apparatus of the present invention is a bonding apparatus that heat-bonds a resin casing and a metal material,
Positioning the resin casing and the metal material, a laser beam irradiation means for heating and joining the metal material with a laser beam from a surface opposite to the surface of the metal material opposite to the joint surface with the resin casing. A pressure fixing mold for pressurizing and heating means for heating the pressure fixing mold,
The pressure fixed mold includes a movable mold and a fixed mold. The resin casing and the metal material are sandwiched between the movable mold and the fixed mold at a predetermined position, and the movable mold is heated by the heating means. In addition, the metal material is pressed against the resin housing by the movable mold, and the resin housing and the metal material are joined by irradiating the laser light with the laser light irradiation means.

  Furthermore, the laser bonding apparatus of the present invention is characterized in that laser irradiation is directly performed on the metal material to be bonded by a laser beam irradiation means.

  Furthermore, in the laser bonding apparatus of the present invention, a pressurizing material made of a material different from a metal material is disposed between the laser beam irradiation means and the metal material so as to be in close contact with the metal material, and the pressurizing material The surface of the substrate is irradiated with laser to conduct heat to the metal material and to be joined to the resin casing.

  Furthermore, in the laser bonding apparatus of the present invention, a pressurizing material made of a material different from a metal material is disposed between the laser beam irradiation means and the metal material so as to be in close contact with the metal material, and the pressurizing material The surface of the substrate is irradiated with laser to conduct heat to the metal material and to be joined to the resin casing.

  Furthermore, in the laser bonding apparatus of the present invention, the pressurizing material made of a material different from the metal material is made of a material having a higher laser light absorption rate than the metal material.

  Furthermore, the laser bonding apparatus of the present invention is characterized in that the pressurizing material made of a material different from the metal material is made of a material having a lower thermal conductivity than the metal material.

  Furthermore, the laser bonding apparatus of the present invention is characterized in that the pressurizing material made of a material different from the metal material is made of a material having higher heat resistance than the metal material.

  Furthermore, the laser bonding apparatus of the present invention is characterized in that the fixed die is also provided with a heating element.

The laser bonding method of the present invention is a bonding method in which a resin casing and a metal material are heated and bonded,
The resin casing and the metal material are sandwiched and positioned at a predetermined position between the movable mold and the fixed mold of the pressure fixed mold,
While heating the pressure fixed mold by a heating means, pressurizing the metal material to the resin casing by the movable mold,
By joining the resin casing and the metal material by irradiating the metal material with a laser beam from a surface opposite to the joint surface of the metal material with the resin casing by the laser beam irradiation means for heat bonding. It is characterized by performing.

  Furthermore, the laser bonding method of the present invention is characterized in that the temperature of the metal material is set higher than the temperature of the resin casing by the heating means before heat bonding by laser irradiation.

  Further, in the laser bonding method of the present invention, a pressure material made of a different material from the metal material is disposed between the laser beam irradiation means and the metal material so as to be in close contact with the metal material. The surface of the substrate is irradiated with laser, and is thermally conducted to the metal material to be joined to the resin casing.

Furthermore, the laser joining method of the present invention is a joining method in which a resin casing and a metal material are joined by heating,
When the bonding surface of the metal material to the resin casing is bonded by the laser beam irradiation means for heat bonding, a convex portion is provided in the bonding portion of the resin casing,
The surface shape of the joint of the previous metal material
(1) The roughened surface is Ra: 0.4 μm to 2.5 μm,
(2) Or, the groove shape is a groove width: 0.05 mm to 0.2 mm, a groove depth: 0.05 mm to 0.2 mm,
(3) Or, the hole shape is any one of diameter: 0.05 mm to 0.2 mm, hole depth: 0.02 mm to 0.2 mm,
(4) or these (1) (2) (3) from the combination of two or more,
The resin case is bonded to the metal material by irradiating the metal material with laser light from a surface opposite to the bonding portion.

  According to the present invention, it is possible to perform laser bonding of a resin and a metal with high strength and high reliability with a short tact time without being greatly influenced by the light absorption rate of the metal surface. In addition, since the laser power required for bonding can be significantly reduced by heating the resin casing and the metal material to a predetermined temperature in advance, it contributes to a significant reduction in apparatus and product costs. In addition, material limitations can be greatly reduced.

FIG. 1 is an example of a perspective view showing an embodiment of a laser bonding apparatus for a resin casing and a metal material according to the present invention. 2 is a cross-sectional view taken along the line AA showing the detailed configuration of FIG. FIG. 3 is a plan view showing an example of the pattern of the joint surface. FIG. 4 is an example of a perspective view showing another embodiment of a laser bonding apparatus for a resin casing and a metal material. FIG. 5 is a cross-sectional view taken along the line AA showing the detailed configuration of FIG. FIG. 6 is a cross-sectional view showing another embodiment of a laser bonding apparatus for a resin casing and a metal material according to the present invention. FIG. 7 is a cross-sectional view showing another embodiment of a laser bonding apparatus for a resin casing and a metal material according to the present invention. FIG. 8 is a cross-sectional view showing another embodiment of the resin casing and metal material laser joining apparatus of the present invention. FIG. 9 is a cross-sectional view showing another embodiment of the resin casing and metal material laser joining apparatus of the present invention. FIG. 10 is a cross-sectional view showing another embodiment of a laser bonding apparatus for a resin casing and a metal material according to the present invention. FIG. 11 is a cross-sectional view showing another embodiment of a laser bonding apparatus for a resin casing and a metal material according to the present invention. FIG. 12 is a perspective view schematically showing a required portion of a laser joining apparatus for laser joining a resin casing and a metal material according to the present invention. FIG. 13 is a cross-sectional view of a required portion of a heating and pressing jig for producing a test piece bonded by the laser bonding apparatus of the present invention. FIG. 14 is a graph comparing the bonding strengths of test pieces laser-bonded at room temperature and 150 ° C. under the same laser irradiation conditions. FIG. 15 is a graph showing the relationship between the heating temperature and laser power during laser bonding. FIG. 16 is a graph showing the relationship between the heating temperature during laser bonding and the moving speed of the laser irradiation apparatus. FIG. 17A is a plan view showing a joint portion of a metal material subjected to grooving. FIG. 17B is a cross-sectional view taken along plane AA in FIG. 17A. FIG. 18A is a plan view showing a joint portion of a metal material subjected to hole machining. 18B is a cross-sectional view taken along plane AA in FIG. 18A. FIG. 19 is a graph showing the bonding strength when aluminum materials having different surface shapes are bonded at the same room temperature. FIG. 20 is a cross-sectional view showing a heating and pressing jig when a resin test piece having a shape different from that of the resin test piece shown in FIG. 13 is joined to an aluminum material. FIG. 21 is a graph showing the bonding strength when the resin test piece and the aluminum material shown in FIG. 20 are bonded at 150 ° C. and the laser power is 0.3.

  Embodiments of the laser bonding apparatus of the present invention will be described below. The thermoplastic resin used in the present invention is made of an amorphous or crystalline resin. Non-crystalline resins include polystyrene (PS), acrylonitrile styrene (AS), acrylonitrile butadiene styrene copolymer (ABS), polyetherimide (PEI), polycarbonate (PC), polyarylate (PAR), and polymethylmethacrylic. Examples include methyl acid (PMMA), cycloolefin polymer (COP), cycloolefin copolymer (COC), polysulfone (PSF), polyethersulfone (PES), polyvinyl chloride (PVC), and polyvinylidene chloride (PVDC). . As crystalline resins, polyethylene (PE), polypropylene (PP), polyoxymethylene (POM), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN) ), Polyphenylene sulfide (PPS), nylon 6 (PA6), nylon 66 (PA66), nylon 6T (PA6T), polyetheretherketone (PEEK), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), and the like. It is done. In addition, those alloy materials, inorganic materials such as glass fibers, and thermoplastic resins containing special additives are also targeted. In general, an amorphous resin is excellent in moldability and transparency, whereas a crystalline resin is excellent in heat resistance and chemical resistance. Further, not only a thermoplastic resin but also a thermosetting resin such as an epoxy resin may be used.

  In particular, in the case of the present invention, the metal material and the resin are heated and pressed with a jig, and the laser beam is irradiated from the metal material side, so that the colored state of the thermoplastic resin or the thermosetting resin can be any state. good. Further, it is possible to heat the metal material through a member having a high absorption rate of laser light.

  Examples of metals to be joined include iron, aluminum, copper, nickel, gold, titanium, alloys (stainless steel, brass, aluminum alloys, phosphor bronze, etc.), die casting, etc., and metal coatings (plating, vapor deposition films, etc.). This also applies to other materials. Further, not only metal but also ceramics can be joined.

  Materials that have a high absorption rate of laser light to efficiently heat the metal materials to be joined include iron, aluminum, copper, nickel, gold, titanium, alloys (stainless steel, brass, aluminum alloys, phosphor bronze, etc.), die casting The surface absorptance must be 70% or more with respect to the incident laser wavelength based on a material such as various ceramics.

  Lasers with wavelengths in the infrared region, including semiconductor lasers, YAG lasers, and fiber lasers, are effective in terms of cost for the light source used for laser bonding, but other wavelengths are used to support light absorption by the metal material to be heated. But it ’s okay. Further, the intensity distribution of the laser light source can be changed to various intensity distributions depending on attached lenses such as Gaussian, top hat and ring type.

  Laser bonding conditions take into account the heating temperature of the resin and metal, and take into account the light absorption rate, thermal conductivity, heat resistance, rigidity, etc. of the metal material at the laser irradiation wavelength, and then the laser spot size, power, and irradiation time. Determine the pressure.

  Hereinafter, examples will be described with reference to FIGS.

  FIG. 1 is an example of a perspective view showing an embodiment of a laser bonding apparatus for a resin casing and a metal material according to the present invention. In the present embodiment, the pressure fixing mold is configured to pressurize and heat a joined body (resin housing and metal material) between the upper mold 1 which is a frame-shaped movable mold and the lower mold 2 which is a stationary mold. It has become.

  2 is a cross-sectional view taken along the line AA showing the detailed configuration of FIG. Here, as an example, a case where the sensor component 6 is joined will be described with reference to schematic views. 2 shows a state in which a sensor component 6 and a resin casing 7 each having an electronic component 5 fixed on a metal material 3 with an adhesive 4 or the like are sandwiched between an upper mold 1 and a lower mold 2. The upper die 1 has a frame shape with a hole 1 a formed so that the laser beam condensing unit 11 can approach the metal material 3. The hole 1a of the upper mold 1 is formed in a taper shape with its inner periphery protruding from the top to the bottom. Thereby, the pressure by the upper mold 1 and the lower mold 2 can be effectively applied to the contact portion of the metal material 3 with respect to the resin casing 7, that is, the bonding surface 9. As a result, the joint surface 9 of the resin casing 7 and the metal material 3 can be brought into close contact with each other, airtightness is maintained, and there is no possibility that bubbles or the like are generated on the joint surface 9.

  The lower mold 2 is provided with a positioning recess 2a so that the sensor component 6 and the resin casing 7 are not displaced even if they are pressed by the upper mold 1. Even if the resin casing 7 is pressed by the upper mold 1, the recess 2 a can prevent the resin casing 7 from being deformed. In the state shown in FIG. 2, the metal material 3 is heated to a predetermined temperature by a heater 8 which is a heating body provided on the frame-shaped upper mold 1. By heating the metal material 3, softening at the joint portion of the resin casing 7 is promoted, and the degree of adhesion between the joint portions is increased. In the resin casing 7, the temperature of the resin casing 7 is set lower than that of the metal material 3 to be heated, thereby preventing deformation of the resin casing 7 itself due to heating. As for the heating method, it goes without saying that any method such as an IR lamp or LED may be used in addition to the heater heating. Moreover, in order to suppress the temperature change to the laser beam condensing unit 11, it is possible to have a heat insulating structure (not shown) in the upper part and the outer peripheral part so as to reduce heat radiation from the upper mold 1. Further, the joint surface 9 between the metal material 3 and the resin casing 7 is held and fixed in a state where a predetermined pressure is applied. In this state, the laser beam 10 is irradiated from the laser beam condensing unit 11 to the metal material 3, and the bonding surface 9 of the metal material 3 and the resin casing 7 is continuously bonded while scanning along a predetermined pattern. To do.

  FIG. 3 is a plan view showing an example of the pattern of the joint surface. As the joining order 20, for example, continuous irradiation is performed in the order of C 1 → C 2 → C 3 → C 4, and a continuous locus 21 is formed on the joining surface 9 to hermetically seal the metal material 3 and the resin casing 7.

  Normally, when the laser beam 10 is irradiated from the metal material 3, for a metal material having a small light absorption rate, for example, aluminum or copper for infrared light, the light absorption rate is increased on the laser irradiation surface of the metal material to be joined. Processing has to be performed, and the increase in cost has been an issue. In addition, depending on the product form, such treatment may not be performed, and there is a possibility that the bonding property is deteriorated. Furthermore, the joining method using the laser beam 10 may not be applied depending on the product form. Further, since laser irradiation is performed from the metal material 3 side, in order to avoid deterioration of the laser light source due to reflection of the metal material 3, for example, the laser beam is inclined by about 10 to 15 ° with respect to the metal material 3 to which the laser light source is bonded. 10 had to be irradiated. However, there has also been a problem that when the laser is tilted by about 10 to 15 °, the laser bonding surface is less likely to be uniform than when it is not tilted.

  On the other hand, in the case of a resin casing, it is usual for a thermoplastic resin to form a casing shape by injection molding or the like. At this time, in the resin molded product, there is a possibility that the outer shape of the molded product may be warped, distorted, twisted or sinked on the molded surface due to internal stress generated during molding. Due to these factors, there is a possibility that non-uniformity of the shape of the joint surface of the resin casing occurs. This non-uniformity of the joining surfaces may cause variations in the joining state when joining the metal material and the resin casing, and is an important issue in ensuring reliability.

  In contrast, the present invention, as shown in FIG. 1, heats the upper mold 1 and the metal material 3 to a predetermined temperature before joining them, and adds the joined product between the upper mold 1 and the lower mold 2. By pressing, the joint surface of the resin casing is softened, and there is an effect of correcting warpage, distortion, twist, surface sink, and the like that are likely to occur on the joint surface. Moreover, the effect which imitates the joining surface of a metal material arises by heating and pressurizing with the metal material to join. As a result, the degree of adhesion at the bonding interface is improved, so that heat can be efficiently transferred and high strength and uniform bonding can be achieved. Moreover, the metal material 3 and the resin casing 7 are pressed by the upper mold 1 and the lower mold 2 to improve the adhesion, thereby improving the efficiency of heat conduction and reducing the laser beam irradiation energy required for bonding. .

  In particular, a metal material having a low light absorption rate, such as aluminum or copper for infrared light, has an effect of greatly reducing the laser beam irradiation energy by heating. In addition, the target products include not only the housing of the product on which the electronic component 6 is mounted, but also products such as biochips, electronic control units (ECUs), connectors, power modules, and all products that can be laser-bonded. It is valid.

  FIG. 4 is an example of a perspective view showing another embodiment of a resin / metal laser bonding apparatus. Of the resin and laser bonding apparatus shown in FIGS. 1 and 2, the description of the parts having the same configurations and functions shown in FIG.

  In the present embodiment, an example in which the joining shape of the resin casing and the metal material is increased will be described. That is, a pressure piece 30 for uniformly pressing the metal material 3 at the center of the frame-shaped upper mold 1 and a transparent material 31 (for example, glass) for fixing the upper mold 1 and the pressure piece 30 are provided. It has a configuration with. The laser beam 10 passes through the transparent material 31.

  FIG. 5 is a cross-sectional view taken along the line AA showing the detailed configuration of FIG. A transparent material 31 for fixing the upper mold 1 and the pressure piece 30 is provided. By providing the pressurization piece 30, pressurizing the central portion of the metal material 3 in the case of increasing the size prevents the deformation of the metal material 3 and has an effect of maintaining the adhesion degree of the joint surface. Although not shown, depending on the joining shape, it is possible to provide a heating part in the pressurizing piece 30 for heating so that even a large shape can be heated uniformly.

  It goes without saying that various metal materials and various ceramics may be used as the material of the heating piece 30. Depending on the bonding shape, a heat insulating material may be used to prevent heat dissipation during heating of the metal material and stabilize the heating temperature.

  FIG. 6 is a cross-sectional view showing another embodiment of the resin and metal laser bonding method of the present invention. A different material 40 (metal material, ceramics, etc.) having a large light absorption rate to be bonded is installed on the upper surface portion of the metal material 3 to be bonded. As a result, it was found that heat conduction was caused in the metal material 3 to be bonded via the different material 40, and the resin casing 7 and the metal material 3 could be bonded with high strength and uniformity. For example, when joining aluminum or copper, high strength and uniform bonding can be achieved with less laser light irradiation energy by using a stainless steel material with a high absorption rate of laser light in the infrared region and a low thermal conductivity. effective. That is, by using another material 40 having a low thermal conductivity, the energy irradiated to the joint is heated without being widely diffused, and therefore, the temperature becomes high in a narrow range. For this reason, it becomes high temperature with little irradiation energy, and there exists an effect which can heat a metal material efficiently by heat conduction. In addition, as the different material 40, it is desirable to select and combine materials having higher rigidity, heat resistance, and melting point than the metal 3 to be joined.

  FIG. 7 is a cross-sectional view showing another embodiment of the resin and metal laser bonding method of the present invention. In the present embodiment, an example in which the joint shape between a resin and a metal is increased will be described. That is, another material 40 (metal material, ceramics, etc.) having a high light absorption rate to be bonded is installed on the upper surface portion of the metal material 3 to be bonded. As a result, it was found that heat conduction was caused in the metal material 3 to be bonded via the different material 40, and the resin casing 7 and the metal material 3 could be bonded with high strength and uniformity. It is desirable to select and combine materials having higher rigidity, heat resistance, and melting point than the metal 3 to be joined.

  For example, when aluminum or copper is desired to be joined, a stainless steel material having a high absorption rate of laser light in the infrared region can be used, which has the effect of being able to join with high intensity and uniformity with less laser light irradiation energy.

  FIG. 8 is a cross-sectional view showing another embodiment of the resin and metal laser bonding method of the present invention. In order to heat the resin casing 3, a heater 8 similar to the upper mold 1 is provided in the lower mold 2. This is an example in the case of using a highly heat conductive resin material or the like as a housing material. Providing the heater 8 in the lower mold 2 has the effect of heating and holding the joint surface at a predetermined temperature.

  FIG. 9 is a cross-sectional view showing another embodiment of the resin and metal laser bonding method of the present invention. An example will be described in which the joint shape of the resin and metal is increased in size and a highly heat conductive resin material or the like is used as the casing material. In order to heat the resin casing 3, a heating body 8 similar to the upper mold 1 is provided on the lower mold 2. Providing the heater 8 in the lower mold 2 has the effect of heating and holding the bonding surface at a predetermined temperature even when used as a housing material with a resin material having high thermal conductivity. Needless to say, the same effects can be obtained by providing the heater 8 in the lower mold 2 in the structures described in the third and fourth embodiments.

  FIG. 10 is a cross-sectional view showing another embodiment of the resin and metal laser bonding method of the present invention. This embodiment is characterized in that fine irregularities 45 are formed on the laser irradiation surface side above the joint surface 9 of the metal material 3 to improve the laser absorption rate. Thereby, the laser power required for bonding can be reduced, and high-efficiency laser bonding is possible. In addition, it is desirable that the metal portion 46 in contact with the upper mold 1 or the like is as small as possible in order to maintain high thermal conductivity.

  FIG. 11 is a cross-sectional view showing another embodiment of the resin and metal laser bonding method of the present invention. An example will be described in which the joint shape of the resin and metal is increased in size and a highly heat conductive resin material or the like is used as the casing material. The present embodiment is characterized in that fine irregularities 45 are formed on the laser irradiation surface side of the upper part of the different kind material 40 placed on the upper part of the metal material 3 to improve the laser absorption rate. Thereby, the laser power required for bonding can be reduced, and high-efficiency laser bonding is possible. In addition, it is desirable that the metal portion 46 with which the upper mold 1 and the pressurizing piece 30 are in contact is as small as possible in order to maintain high thermal conductivity. Needless to say, the same effects can be obtained by providing the fine unevenness 45 on the laser irradiation surface side in the structures described in the third and fourth embodiments.

  FIG. 12 is a perspective view schematically showing a required part of a laser bonding apparatus for laser bonding a resin and a metal according to the present invention. Here, the drive unit 54 in which the laser beam condensing unit 50 is fixed to the Z-axis of the three-axis drive unit in the X-axis direction 53, the Y-axis direction 52, and the Z-axis direction 51 is driven, and the heating / pressurizing jig An example in which 55 is fixed on the stage 56 will be described. That is, the drive unit draws a predetermined pattern according to a program inputted in advance. Further, the laser beam condensing unit 50 fixed in the Z-axis direction 51 has moved to a height focused on the joined body.

  On the other hand, a joined body made of a resin casing and a metal material is installed in a jig for heating and pressurizing. As the heating, there is a heating method directly in the jig or a method in which preliminary heating is performed in advance in a separate process and then placed in the jig. By this method, there is an effect that stable production is possible and a highly reliable product can be manufactured.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. It is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment. For example, the shape of the resin casing 7 is a box shape in order to explain the advantages of pressurization by the upper mold 1 and the lower mold 2, but the present invention is not limited to this, and the resin casing 7 is used to insert terminals and cords. A notch or a hole may be formed. In that case, it is not necessary to irradiate the laser beam to the part which does not contact the metal material 3 and does not form the joint surface. Also, the heater 8 can use various heating means such as resistance heating that generates heat when an electric current is passed through an element having high resistance, and infrared heating that uses far infrared rays.

  The effect of reducing laser output by heating and pressing in Examples 1 to 8 will be described with reference to the following drawings. As an example, the metal material performed in Example 1, Example 2, Example 5, Example 6, and Example 7 and the resin of the resin casing were used as test pieces. FIG. 13 shows a cross section of a heating and pressing jig for producing a test piece for measuring the bonding strength. Here, a structure in which the heater 8 is installed in the upper mold 1 was used. As the test piece 105, it created using the aluminum material 100 (A5052P) and the PBT resin, for example using the Duranex (trademark) PBT resin 7407 by Polyplastics Co., Ltd., for example. The dimensions of the test piece 105 were 20 mm × 70 mm × 1 mm, and the test speed was 1 mm / min. The surface of the aluminum material on the laser beam irradiation side is a polished surface (Ra: about 0.4 μm), the roughened surface is a # 80 sandblasted surface (Ra: about 2.5 μm), and the # 400 sandblasted surface (Ra: 1.3 μm). The joint surface is a polished surface. Hereinafter, although referred to as a polished surface and a roughened surface, when the degree of roughness of the treated surface is expressed by Ra, it may be expressed including the surface state of the polished surface and the surface state of the roughened surface.

FIG. 14 is a comparative example of the bonding strength at room temperature and 150 ° C. heating when the laser irradiation conditions (laser power: 350 W, laser irradiation apparatus moving speed: 3 mm / second) are the same. The bonding strength when heated at 150 ° C. with respect to room temperature was about twice as high as relative value = 1.9. However, when heated to 150 ° C., the resin breaks, and the actual bonding strength at the interface can be said to be higher. Therefore, it can be determined that the bonding strength is greatly improved by the heating and pressing effect.
FIG. 15 shows the relationship between the heating temperature by the heater 8 and the laser power. Here, when the moving speed of the laser irradiation device is constant, the surface of the aluminum material is a polished surface, and the bonding strength at room temperature (25 ° C.) is the reference value = 1, the value of the laser power equivalent to that value. Is shown. FIG. 14 shows that the laser power tends to decrease as the heating temperature increases. For example, when compared at a heating temperature of 150 ° C., the relative value is 0.3 as compared to the room temperature, indicating that a laser power of about 1/3 at room temperature is sufficient, and there is a significant reduction effect. It can also be seen that if a roughened surface with a high absorption rate of laser light is used, the reduction effect is further greatly reduced to about 1/10.

  As described above, when joining the same moving speed of the laser irradiation device in the two cases where the temperature of the metal material is the same as the room temperature and when the metal material is pre-heated, the same bonding strength is obtained. It has been found that the laser power can be greatly reduced in the case where the metal material is preheated. Accordingly, laser power can be suppressed by heating the metal material and then performing laser bonding, thereby reducing the manufacturing cost and saving energy.

  FIG. 16 shows the relationship between the heating temperature by the heater 8 and the moving speed of the laser irradiation apparatus. Here, when the laser power is constant, a polished surface is used on the surface of the aluminum material, and the bonding strength at room temperature (25 ° C.) is set to the reference value = 1, the moving speed of the laser irradiation apparatus is equivalent to that value. The value is shown. From the figure, the heating temperature increases and the transfer speed of the laser irradiation device tends to increase. For example, when compared at a heating temperature of 150 ° C., the relative value is 15 compared to that at room temperature, which indicates that the moving speed of the laser irradiation device is 15 times that at room temperature, and the manufacturing process can be greatly speeded up. It shows that there is. Further, it can be seen that if a roughened surface having a high absorption rate of laser light is used, the speed can be further increased to about 58 times.

  As described above, a rational manufacturing process such as a reduction in laser power and an increase in moving speed of the laser irradiation apparatus can be realized by appropriately configuring a joining apparatus depending on the length of the product joining distance or the difference in production amount. Needless to say, Example 3 and Example 5 have the same effect.

  Subsequently, an experiment performed on two cases of FIGS. 17 and 18 as an example of a roughened surface will be described. FIG. 17A and FIG. 17B show a joining portion of an aluminum material, which is a metal material that is grooved in the vertical and horizontal directions. FIG. 17A is a plan view, and FIG. 17B is a cross-sectional view taken along line AA. The groove width X is preferably about 0.05 mm to 0.2 mm, and the groove depth is preferably about 0.05 mm to 0.2 mm.

  FIG. 18 is a schematic view in which holes are drilled in the aluminum joint portion in place of vertical and horizontal grooves. 18A is a plan view, and FIG. 18B is a cross-sectional view taken along line AA. As for the shape of the hole, the diameter is preferably about 0.05 mm to 0.2 mm, and the depth of the hole is preferably about 0.02 mm to 0.2 mm. Needless to say, the resin penetrates into the concave portion on the surface where the hole is formed. Further, the shape of the protruding portion 115 is not limited to the groove shape, and may be a shape as shown in FIG. There is no problem even if the shape of the hole is not only a quadrangular prism but also a cylindrical shape. These shapes can be selected as appropriate in consideration of the effect of penetration into the recess by heating.

  Here, as an example, the joining portion of the grooved aluminum material 110 was processed in the vertical and horizontal directions with a groove width X of about 0.1 mm and a groove depth L of 0.1 mm. The processing method can be selected as appropriate, such as laser processing or machining. Further, the protruding portion 115 is a quadrangular prism here, and has a shape of about 0.1 mm × 0.1 mm × 0.1 mm. It goes without saying that the groove direction may be one direction.

As described above, in the bonding method of heat bonding the resin casing and the metal material as an embodiment of the present invention,
When the bonding surface of the metal material to the resin casing is bonded by the laser beam irradiation means for heat bonding, a convex portion is provided in the bonding portion of the resin casing,
The surface shape of the joint of the previous metal material
(1) The roughened surface is Ra: 0.4 μm to 2.5 μm,
(2) Or, the groove shape is a groove width: 0.05 mm to 0.2 mm, a groove depth: 0.05 mm to 0.2 mm,
(3) Or, the hole shape is any one of diameter: 0.05 mm to 0.2 mm, hole depth: 0.02 mm to 0.2 mm,
(4) or these (1) (2) (3) from the combination of two or more,
The resin casing and the metal material are joined by irradiating the metal material with a laser beam from a surface opposite to the joint portion.

  FIG. 19 shows the relationship of bonding strength when aluminum materials having different surface shapes on the polished surface and grooved surface are bonded under the same conditions at room temperature. The pressurization was performed using the heating and pressurizing jig shown in FIG. When the bonding strength of the polished surface is 1.0, the relative value of the groove processed surface is reduced to about 0.7. Further, by observing the fracture surface and the cross section, it was confirmed that the fracture occurred at the interface and the resin was not filled in the groove (recess). Therefore, it can be determined that the bonding strength is reduced because the resin does not enter the groove (concave portion) on the groove processing surface by the laser irradiation. Therefore, the resin test piece whose shape has been changed in consideration of heat, sink marks, twists, and warp deformation that are likely to occur in the molded product is shown below.

FIG. 20 shows a cross section of the heating and pressing jig when the shape of the resin test piece is changed and the resin test piece is joined to the aluminum material. The resin test piece 120 has a convex shape 125 only at the joint portion. Here, the shape of the protrusion was about 1 mm in height and 20 mm in width. The shape may be changed as appropriate. An aluminum test piece in which a groove is formed on the upper surface is placed and irradiated with laser light 10 from above.
In FIG. 21, the heating temperature is 150 ° C., and the laser power is as small as 0.3 compared to room temperature, that is, the bonding strength depending on the aluminum material surface shape when the laser irradiation conditions are the same as the heating temperature of 150 ° C. This shows the relationship. It can be seen that, in combination with the resin test piece having the protrusion, the relative value of the bonding strength is as high as 1.1 on the grooved surface compared to the polished surface. When the aluminum material was used as the polished surface, the strength was the same, whereas the strength improvement was confirmed on the grooved surface. This is presumably because the resin was infiltrated into the groove (concave portion) of the groove processing surface by laser irradiation and the bonding strength was improved.

  From these facts, it is necessary to apply protrusions to the joints in consideration of sink marks, twists, warp deformation, etc. of the molded product and to use heating and pressurization together on the surface having a large convex recess such as the above-mentioned grooved surface. Even if it exists, there exists an effect which welds fully and increases joint strength.

1 Upper mold (movable)
1a Hole 2 Lower mold (fixed mold)
2a Groove 3 Metal material 4 Bonding agent 5 Electronic component 6 Sensor component 7 Resin housing 8 Heater (heating body)
9 Bonding surface 10 Laser beam 11 Laser beam condensing unit (Laser beam irradiation means)
20 Joining sequence 21 Consecutive locus 30 Pressing piece 40 Different material with large light absorption rate 45 Fine irregularities on laser irradiation surface side 50 Laser beam condensing unit 55 Heating / pressurizing jig 100 Aluminum material 105 Resin test piece 110 Groove Attached aluminum material 115 Protruding part 120 Resin test piece 125 Convex part

Claims (10)

A joining device that heat-joins a resin casing and a metal material,
Positioning the resin casing and the metal material, a laser beam irradiation means for heating and joining the metal material with a laser beam from a surface opposite to the surface of the metal material opposite to the joint surface with the resin casing. A pressure fixing mold for pressurizing and heating means for heating the pressure fixing mold,
The pressure fixed mold includes a movable mold and a fixed mold. The resin casing and the metal material are sandwiched between the movable mold and the fixed mold at a predetermined position, and the movable mold is heated by the heating means. In addition, the metal member is pressed against the resin casing by the movable mold, and the laser casing is irradiated with the laser beam by the laser beam irradiating means to bond the resin casing and the metal member. apparatus.   2. The laser bonding apparatus according to claim 1, wherein the metal material to be bonded by the laser beam irradiation means is directly irradiated with a laser beam.   The laser bonding apparatus according to claim 1 or 2, wherein a pressurizing material made of a different material from the metal material is disposed between the laser light irradiation means and the metal material so as to be in close contact with the metal material, A laser joining apparatus, wherein the surface of the pressurizing material is irradiated with a laser and thermally conducted to the metal material to be joined to the resin casing.   4. The laser bonding apparatus according to claim 3, wherein the pressurizing material made of a material different from the metal material is made of a material having a higher laser light absorption rate than the metal material.   4. The laser bonding apparatus according to claim 3, wherein the pressurizing material made of a material different from the metal material is made of a material having a lower thermal conductivity than the metal material.   4. The laser bonding apparatus according to claim 3, wherein the pressurizing material made of a material different from the metal material is made of a material having higher heat resistance than the metal material.   2. The laser bonding apparatus according to claim 1, wherein the fixed die is also provided with a heating body. A joining method in which a resin casing and a metal material are joined by heating,
The resin casing and the metal material are sandwiched and positioned at a predetermined position between the movable mold and the fixed mold of the pressure fixed mold,
While heating the pressure fixed mold by a heating means, pressurizing the metal material to the resin casing by the movable mold,
By joining the resin casing and the metal material by irradiating the metal material with a laser beam from a surface opposite to the joint surface of the metal material with the resin casing by the laser beam irradiation means for heat bonding. A laser bonding method characterized in that:   9. The laser bonding method according to claim 8, wherein the temperature of the metal material is made higher than the temperature of the resin casing by the heating means before heat bonding by laser irradiation.   9. The laser bonding method according to claim 8, wherein a pressurizing material made of a different material from the metal material is disposed between the laser beam irradiation means and the metal material so as to be in close contact with the metal material. A laser joining method comprising: irradiating a surface of a pressure member with laser, conducting heat to the metal material, and joining to the resin casing.

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