JP6574881B2 - Bonding structure - Google Patents

Description

  The present invention relates to a light-absorbing member and a light-transmitting member that are overlapped with each other and bonded to each other via a welded portion formed at or near the boundary surface, and a manufacturing method thereof.

  Conventionally, as a method of joining a plurality of members, there is a joining method by laser light irradiation, and among them, recently, it is local heating and there is little thermal damage to the product, and the influence of the welded part on the appearance is also affected. Less laser transmission welding has attracted attention. This joining method uses a member (light transmissive member) that is transparent to laser light on one side of the joining member, and a member (light absorbing member) that is absorbent to laser light on the other side. By irradiating laser light from the light transmitting member side in a state where these are superposed on each other and pressed, the energy of the irradiated laser light is absorbed near the boundary surface of the light absorbing member and generates heat. This is a method in which heat is transmitted to the light transmissive member, both members are melted, and finally, the melted portion is cooled and solidified to join both members.

  There are several important points in this laser transmission welding method, but what is particularly important is to pressurize the members to be joined together to ensure close contact. If there is a gap between the members to be joined, heat generated in the light-absorbing member due to laser irradiation will not be transferred well to the light-transmitting member on the other side, and welding such as bulging, expansion, and explosion will occur due to local temperature rise This is because it becomes defective.

  This pressurization is generally realized by a method in which a glass plate that is transparent to laser light is placed on a light-transmitting member and a pressing pressure is applied to both members via the glass plate ( See Patent Document 1 below). However, in the case of this method, the glass plate is soiled by the soot generated during the heating and melting of the joining member and the vaporized component of the flame retardant, the absorption rate of the glass plate with respect to the laser light is increased, and the glass plate itself is heated to crack. There is a problem. In addition, the dirty glass plate blocks the laser beam, and as a result, sufficient light does not reach the light-absorbing member, resulting in a decrease in welding strength.

  On the other hand, Patent Document 2 below proposes a method in which members to be joined are brought into close contact with each other without using a glass plate. Specifically, in the method described in Patent Document 2, a groove is formed on one of the members to be joined, and the two members are brought into close contact with each other by decompressing the space of the groove. However, when welding is performed by laser irradiation, thermal deformation occurs in the light-transmitting member and a gap is generated between the light-absorbing member and air leaks through the gap, resulting in a decrease in suction adhesion.

JP-A-62-142092 International Publication No. 2010/035696 Pamphlet

  Therefore, an object of the present invention is to provide a joining structure suitable for uniformly and reliably bringing members to be joined together without using a glass plate, and without using a glass plate. An object of the present invention is to provide a method for manufacturing a joined structure capable of uniformly and reliably bringing members to be joined together.

The bonded structure of the present invention for solving the above-described problem includes a light-absorbing member having at least one opening, a light-transmitting member disposed on the light-absorbing member so as to cover the opening, An annular welded portion is formed that surrounds the opening and joins the light absorbing member and the light transmissive member. The annular welded portion is a light transmissive member as viewed in a vertical cross section with respect to the extending direction. The ratio of the area of the light absorbing member side to the area of the side part is in the range of 12 to 35.

  In this case, the ratio is preferably in the range of 19 to 26.

  In the bonded structure of the present invention, the light transmissive member is deformed when the inside of the opening is in a reduced pressure state before the annular welded portion is formed, and becomes a light absorbing member. It is preferably formed in a thin plate shape that is in close contact. In this case, the light transmissive member is deformed when the inside of the opening is decompressed to −80 kPa or more and −20 kPa or less by the gauge pressure before the annular welded portion is formed, and is in close contact with the light absorbing member. It is preferable that the thickness is formed.

  Alternatively, in the bonded structure according to the present invention, the light transmissive member is disposed outside the annular welded portion when the inside of the opening is in a reduced pressure state before the annular welded portion is formed. It is preferable to have a thin piece that deforms and adheres closely to the light absorbing member. In this case, the thin-walled piece is formed to a thickness that deforms and adheres closely to the light-absorbing member when the inside of the opening is decompressed to -80 kPa or more and -20 kPa or less as a gauge pressure before the annular welded portion is formed. It is preferable that

  In any of the above-described bonded structures, it is preferable that the bonded structure includes a dot-shaped weld portion that is positioned adjacent to the annular weld portion and joins the light absorbing member and the light transmissive member.

  In the manufacturing method of the bonded structure of the present invention for solving the above-described problem, the light-absorbing member having at least one opening is overlapped with the light-transmitting member so as to cover the opening, and the light-transmitting member is formed. A method for manufacturing a bonded structure in which a ring-shaped weld is formed so as to surround an opening by irradiating a laser beam from the side, and a light-absorbing member and a light-transmitting member are bonded. An annular groove is formed at a site where the annular welded portion is to be formed, and when forming the annular welded portion, the annular groove is irradiated with laser light from the light transmitting member side. .

  In this case, the groove width of the annular groove is preferably 0.1 mm or more and 3 mm or less.

  The depth of the annular groove is preferably L / 20 (mm) or more and L (mm) or less, where the width of the annular groove is L (mm).

Furthermore, it is preferable that a communication groove for communicating the annular groove and the opening is formed in the light absorbing member.

  Further, in the method for manufacturing a bonded structure according to the present invention, the light transmissive member is deformed when the inside of the opening is in a reduced pressure state before the annular welded portion is formed, and absorbs light. The light-transmitting member is formed in a thin plate shape that is in close contact with the light-transmitting member, and in forming the annular welded portion, the light-transmitting member is deformed by reducing the pressure inside the opening and is in close contact with the light-absorbing member. It is preferable to irradiate laser light from the side. In this case, the light transmissive member is deformed when the inside of the opening is decompressed to -80 kPa or more and -20 kPa or less by the gauge pressure before the annular welded portion is formed, and is closely attached to the light absorbing member. It is preferable to form in thickness.

  Alternatively, in the method for manufacturing a bonded structure according to the present invention, the inside of the opening is depressurized before the annular welded portion is formed outside the annular welded portion of the light transmitting member. When forming the annular welded portion, the thin-walled piece was deformed by reducing the pressure in the opening, and the thin-walled piece was brought into close contact with the light-absorbing member. In this state, it is preferable to irradiate laser light from the light transmissive member side. In this case, the thin-walled piece is deformed when the inside of the opening is decompressed to -80 kPa or more and -20 kPa or less by the gauge pressure in a state before the annular welded portion is formed, and is formed to a thickness that adheres to the light absorbing member. It is preferable to keep it. The thin piece is preferably formed along the peripheral edge of the light absorbing member.

  Further, in the method for manufacturing a bonded structure according to the present invention, after the light transmitting member is superimposed on the light absorbing member and before the annular welded portion is formed, from the light transmitting member side. It is preferable to form a spot-like welded portion that joins the light-absorbing member and the light-transmitting member by irradiating the laser beam.

  Furthermore, in the method for manufacturing a bonded structure according to the present invention, it is preferable to form a suction opening in the light-absorbing member that leads to the opening and communicates with an external pressure reducing device.

  Furthermore, in the manufacturing method of the bonded structure of the present invention, after forming the annular welded portion, the suction aperture is melted by irradiating the laser beam from the light transmissive member side while maintaining the reduced pressure in the aperture. It is preferably occluded.

  Furthermore, in the method for manufacturing a bonded structure according to the present invention, it is preferable to perform pressure reduction in the opening while supplying a purge gas into the opening. In this case, the pressure reduction in the opening and the supply of the purge gas into the opening are preferably performed through a suction opening using a double pipe.

  Further, in the manufacturing method of the bonded structure of the present invention, after the annular welded portion is formed, the reduced pressure in the opening is continuously maintained, or the inside of the opening is pressurized, or the reduced pressure and the pressurized are alternately performed, It is preferable to perform an airtightness test on the annular welded portion by measuring a change in pressure per unit time.

  Furthermore, in the method for manufacturing a bonded structure according to the present invention, the pressure in the opening is constantly detected, and based on the change in pressure, adhesion between the light-absorbing member and the light-transmitting member, annular welding It is preferable to determine the formation start of the part and the completion of the formation of the annular welded part.

  According to the bonded structure of the present invention, the ratio of the area of the light-absorbing member side portion to the area of the light-transmitting member side portion is 12 to 35 when the annular welded portion is viewed in a cross section perpendicular to the extending direction. Therefore, while ensuring the bonding strength between the light transmitting member and the light absorbing member, the thermal effect on the light transmitting member due to the formation of the annular welded portion is reduced. In addition, since thermal distortion of the light transmissive member can be suppressed, excellent suction adhesion between the light absorptive member and the light transmissive member can be obtained. Moreover, according to the manufacturing method of the bonded structure of the present invention, an annular groove is formed at a site where the annular welded portion is to be formed, and the annular welded portion is formed by irradiating the annular groove with laser light. Therefore, in addition to being able to form a welded portion with sufficient width and depth to obtain high bonding strength, the thermal effect on the light transmissive member is reduced, and the light transmissive member in the welding process It is possible to suppress thermal deformation of the film, and it is possible to prevent a decrease in suction adhesion due to the thermal deformation.

  Therefore, according to the present invention, it is possible to provide a joining structure suitable for bringing the members to be joined together uniformly and reliably without using a glass plate, and without using a glass plate. In addition, it is possible to provide a method for manufacturing a joined structure that can uniformly and reliably bring members to be joined together.

FIG. 1: shows the joining structure of one Embodiment of this invention, (a) is a perspective view, (b) is sectional drawing which follows the AA line in (a). Figure 2 shows the bonding structure of another embodiment of the present invention, (a) is a perspective view, (b) is a sectional view taken along line B-B in (a). FIG. 3: shows the joining structure body of further another embodiment of this invention, (a) is a perspective view, (b) is sectional drawing which follows the CC line | wire in (a). 4 (a) and 4 (b) are cross-sectional views showing modifications of the thin-walled pieces in the joint structure shown in FIG. FIG. 5: shows the light absorptive member used for the manufacturing method of the joining structure of one Embodiment of this invention, (a) is a top view, (b) is sectional drawing which follows the DD line | wire in (a). It is. 6A and 6B show a method for manufacturing a bonded structure according to an embodiment of the present invention. FIG. 6A is a cross-sectional view showing an arrangement step and FIG. FIG. 7 is a schematic view showing a pressure adjusting device and a laser irradiation device used in the method for manufacturing a bonded structure according to an embodiment of the present invention. FIGS. 8A to 8D sequentially show a state in which an annular welded portion is formed by irradiating a laser to the annular groove of the light-absorbing member in the method for manufacturing a bonded structure according to an embodiment of the present invention. FIG. FIG. 9 is a cross-sectional view showing an example of another annular groove applicable to the method for manufacturing a bonded structure according to the present invention. FIG. 10 shows a connector of an example according to the embodiment of the present invention, in which (a) is a perspective view and (b) is a cross-sectional view. FIG. 11 shows an example sensor according to an embodiment of the present invention, in which (a) is a perspective view and (b) is a cross-sectional view.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same member or part is attached with a reference numeral obtained by adding either “100” or “200” to the reference numeral, and redundant description is omitted.

  FIG. 1: has shown the joining structure 100 of one Embodiment of this invention, (a) is a perspective view, (b) is sectional drawing which follows the AA line in (a). As shown in this figure, the bonded structure 100 of the present embodiment is overlapped with the light absorbing member 102 having the opening O and the light absorbing member 102 so as to cover the opening O. And a light-transmitting member 106 joined to the light-absorbing member 102 through an annular welded portion 104 that surrounds. Note that “annular” does not mean only a circular shape like a ring, but a continuously closed shape (endless shape). Therefore, “annular” includes not only a circle or an ellipse but also a rectangle, a polygon, and other closed shapes. The welded portion 104 is formed on the boundary surface F between the light transmitting member 106 and the light absorbing member 102, and will be described in detail later. Such a welded portion 104 is formed from the light transmitting member 106 side. The light-absorbing member 102 is irradiated with laser light, and the light-absorbing member 102 is first heated and melted, and the light-transmitting member 106 is melted by the heat, and then the melted portion is solidified. be able to.

The light absorptive member 102 is a member that has a higher absorptance with respect to laser light than that of the light transmissive member 106 and is mainly made of a thermoplastic resin or a thermoplastic elastomer and is formed by injection molding or the like. Can do. Specifically, those having an absorption rate of 10% or more with respect to laser light selected from laser light having a center of oscillation wavelength within a wavelength range of 193 to 10600 nm are preferable. As the laser, for example, a carbon dioxide laser (wavelength of about 10600 nm), a Nd: YAG laser (wavelength of about 1064 nm), a green laser (wavelength of about 532 nm) that is the second harmonic of the Nd: YVO ₄ laser, a diode laser (wavelength of about 532 nm). 800 nm, 840 nm, or 950 nm), excimer laser (wavelength of about 193 nm), and the like. In order to adjust the absorption rate of the light absorbing member 102, a black colorant such as carbon black, a pigment, a dye, or the like can be kneaded with the thermoplastic resin or the thermoplastic elastomer.

  Examples of the thermoplastic resin include polyamide resin, polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenyl ether resin, polystyrene resin, high impact polystyrene resin, hydrogenated polystyrene resin, polyacrylstyrene resin, ABS. Resins, AS resins, AES resins, ASA resins, SMA resins, polyalkyl methacrylate resins, polymethyl methacrylate resins, polycarbonate resins, polyester resins, polyphenylene sulfide, liquid crystal polymers and the like can be mentioned. Examples of the thermoplastic elastomer include styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, PVC-based thermoplastic elastomers, and the like. The thermoplastic resin may be kneaded with glass fiber or mineral as a reinforcing material.

In the illustrated example, the light-absorbing member 102 mainly includes a peripheral wall 108 that defines the opening O, and a bottom wall 110 that closes the lower end of the peripheral wall 108. The cross-sectional shape of the peripheral wall 108 is substantially rectangular, but is not limited thereto, and may be any shape such as a circle, an ellipse, a trapezoid, a polygon, a gourd shape, and the like. As will be described later, the peripheral wall 108 is formed with a suction opening 112 that is connected to the opening O and is suitable for reducing the pressure inside the opening O. The suction opening 112 may be formed in the bottom wall 110. Alternatively, opening the lower end of the peripheral wall 108 without providing the bottom wall 110, it may be used lower end opening as a suction opening 112.

  The light transmissive member 106 is a member that has a lower absorptance for laser light than that of the light absorptive member 102 for the laser light, and is mainly made of a thermoplastic resin or a thermoplastic elastomer, and may be formed by injection molding or the like. it can. Specifically, a laser beam having an absorptance lower than the absorptivity of the light-absorbing member 102 is preferable for a laser beam selected from laser beams having a center of oscillation wavelength within a wavelength range of 193 to 10600 nm.

  Examples of the thermoplastic resin constituting the light transmissive member 106 include polyamide resin, polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenyl ether resin, polystyrene resin, high impact polystyrene resin, hydrogenated polystyrene. Resins, polyacryl styrene resins, ABS resins, AS resins, AES resins, ASA resins, SMA resins, polyalkyl methacrylate resins, polymethyl methacrylate resins, polycarbonate resins, polyester resins, polyphenylene sulfide, liquid crystal polymers, and the like. Examples of the thermoplastic elastomer include styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, PVC-based thermoplastic elastomers, and the like. The thermoplastic resin may be kneaded with glass fiber, mineral, or the like as a reinforcing material. For example, a white pigment or a chromatic colorant such as yellow, green, and red may be kneaded in the thermoplastic resin or the thermoplastic elastomer as long as an absorption rate lower than that of the light absorbing member can be obtained.

  The light transmissive member 106 is deformed when the inside of the opening O is in a reduced pressure state before the annular welded portion 104 is formed, and the peripheral portion thereof is above the peripheral wall 108 of the light absorbing member 102. It is formed in a thin plate shape that is in close contact with the end face. Thereby, even when a gap is generated between the upper end surface of the peripheral wall 108 of the light absorbing member 102 and the light transmitting member 106 when the light transmitting member 106 is overlapped with the light absorbing member 102, Since the light transmissive member 106 can be brought into close contact with the upper end surface of the peripheral wall 108 of the light absorbing member 102 when the inside of the opening O is decompressed through the suction opening 112, vacuum leakage is prevented and the light transmissive member 106 and the light are prevented. Excellent suction adhesion between the absorbent members 102 can be obtained.

  In order to make this more reliable, the light transmissive member 106 deforms when the inside of the opening O is decompressed to −80 kPa or more and −20 kPa or less by gauge pressure before the annular welded portion 104 is formed. Therefore, it is preferable that the thickness be formed so as to exhibit easy deformability to be in close contact with the light absorbing member 102. Specifically, the thickness of the light transmissive member 106 is preferably 0.005 mm to 0.2 mm in order to ensure adhesion by sufficient deformation, and 0.01 mm to 0.1 mm in view of moldability. More preferably.

  The light transmissive member 106 is deformed when the inside of the opening O is decompressed to −80 kPa or more and −20 kPa or less by a gauge pressure before the annular welded portion 104 is formed, and becomes a light absorbing member 102. It is preferable to select or adjust a material having a tensile elastic modulus (Young's modulus) in the range of 0.01 to 18 GPa so as to adhere. When the tensile elastic modulus (Young's modulus) of the light-transmitting member 106 is larger than 18 GPa, it is necessary to form it very thin to facilitate deformation when the inside of the opening O is decompressed, and it is molded as designed. For example, when the light transmissive member 106 is formed by injection molding, the resin does not flow in a thin portion, which may cause molding defects. On the other hand, when the tensile elastic modulus (Young's modulus) of the light-transmitting member 106 is less than 0.01 GPa, the rigidity of the material itself becomes low, so that it becomes difficult to maintain its own shape, and the target shape is in the target position. It becomes difficult to position with. In order to balance the deformability, moldability, and positioning property of the light transmissive member 106 at a higher level, the material of the light transmissive member 106 has a tensile elastic modulus (Young's modulus) in the range of 6 to 10 GPa. It is more preferable to select or adjust. This tensile elastic modulus (Young's modulus) conforms to the provisions of JIS K7161, the test piece described in JIS K7162 is mounted on a tensile tester, and a stress-strain curve is drawn from the stress and strain (deformation amount). Can be obtained from In this case, if the stress-strain curve is not linear and it is difficult to determine the slope, a secant coefficient (slope of the straight line connecting the point on the stress-strain curve and the origin) should be used as an alternative coefficient for Young's modulus. Can do.

  Moreover, in the joining structure 100 of this embodiment, as shown to Fig.1 (a), the point shape which joins the light absorption member 102 and the light transmissive member 106 in the position adjacent to the cyclic | annular welding part 104. FIG. The welding part 114 is provided. As a result, the bonding strength between the light absorbing member 102 and the light transmitting member 106 is further increased.

  The spot-like welded portion 114 can be formed by irradiating laser light from the light transmitting member 106 side toward the light absorbing member 102, similarly to the annular welded portion 104. The spot-like welded portion 114 is preferably formed adjacent to the corner portion when the light transmissive member 106 is substantially rectangular. According to this, the spot-like welded portion 114 is formed into the annular welded portion 104. In combination with the adhesion effect due to the easy deformation of the thin plate-like light-transmitting member 106 at the time of decompression in the opening O, effectively suppressing the warp due to the heat-deformation of the light-transmitting member 106 when forming the film. Further, it is possible to obtain even more excellent suction adhesion between the light transmitting member 106 and the light absorbing member 102.

  And in the joining structure 100 of this embodiment, as shown in the enlarged view in FIG.1 (b), seeing in the cross section perpendicular | vertical with respect to the extension direction of the cyclic | annular welding part 104, the light transmissive member 106 of the welding part 104 is shown. The portion on the light-absorbing member 102 side (the boundary surface F in the drawing) with respect to the area S1 of the portion on the side (the portion above the boundary surface F in the drawing and hereinafter also referred to as “first portion”). The ratio of the area S2 of the lower portion, hereinafter also referred to as “second portion”) is in the range of 12 to 35. When the ratio is less than 12, peeling (interface peeling) or welding starting from the boundary of the annular welded portion 104 when a force is applied to peel the light transmissive member 106 from the light absorbing member 102. There is a possibility that peeling occurs when at least a part of the portion of the portion 104 on the light absorbing member 102 side is integrated with the light transmitting member 106. Also, this type of delamination is difficult to test non-destructively in industrial production. When the ratio of the area S2 to the area S1 is 12 or more, the welded portion 104 hardly peels off, and when a force is applied to peel off the light-transmitting member 106 from the light-absorbing member 102, the light-transmitting member 106 is applied. Alternatively, since the “light-absorbing member 102 itself” is destroyed, “member destruction” occurs, the strength of the members 102 and 106 may be controlled when designing (setting) the welding strength, and stable production can be achieved. On the other hand, if the ratio exceeds 35, it is necessary to increase the power or extend the irradiation time in order to allow the laser beam to reach deep into the light-absorbing member 102. There is a possibility that bulges, bubbles, melting on the surface, carbonization or discoloration associated with burning) and thermal effects on the light absorbing member 102 (carbonization associated with burning, generation of bubbles) may become apparent. In order to achieve avoidance of these thermal effects and suppression and prevention of peeling at the welded portion 104 in a higher dimension, the ratio of the area S2 to the area S1 is more preferably in the range of 19 to 26.

  In this way, by setting the ratio of the area S2 of the light absorbing member side portion to the area S1 of the light transmitting member side portion of the welded portion 104 within the above range, the annular welded portion 104 is secured while ensuring the bonding strength. The thermal effect on the light transmissive member 106 due to the formation of the film can be reduced and the thermal distortion of the light transmissive member 106 can be suppressed. Excellent suction adhesion between each other can be obtained.

  The welded portion 104 having the areas S1 and S2 under the above ratio can be formed by a method for manufacturing a bonded structure described later with reference to FIG. Further, when calculating the areas S1 and S2, the range (boundary) of the welded portion 104 is cut in a direction orthogonal to the extending direction of the welded portion 104 to create a test piece, and the cross section is optically This can be determined by observing with a microscope or an electron microscope, or by confirming a tomographic image using X-ray CT.

  By the way, when the light transmissive member 106 is manufactured by injection molding, the light transmissive member 106 protrudes to the lower surface side due to the position of the gate, the flow of the molten resin, non-uniform cooling after removal from the mold, and the like. Or warpage that is convex toward the upper surface side may occur. The warpage convex toward the lower surface side is between the peripheral edge of the light transmissive member 106 and the upper end surface of the peripheral wall 108 of the light absorbent member 102 when the light transmissive member 106 is superimposed on the light absorbent member 102. This is not preferable because a gap is generated. Therefore, in this embodiment, the concave portion 116 having a reduced thickness is formed on the lower surface of the light transmitting member 106 (the surface on the light absorbing member 102 side) over 50% or more of the inner region of the annular welded portion 104. Thus, the direction of warping is guided in a direction that is convex toward the upper surface side. When the formation region of the concave portion 116 is less than 50% of the inner region of the annular welded portion 104, it is sufficient to induce the warp of the entire light transmitting member 106 with respect to the shrinkage of the resin material that causes the warp. There is a possibility that power cannot be obtained. In order to prevent an excessive amount of warpage, the depth of the recess 116 is preferably 50% or less of the plate thickness. When the depth of the recess 116 exceeds 50% of the plate thickness, the rigidity of the light-transmitting member 106 is reduced and twisted with respect to the shrinkage of the resin material that causes warping. There may be a gap between the light-transmitting member 106 and the light-absorbing member 102, resulting in insufficient adhesion, and misalignment or welding failure (excessive temperature rise or unmelted due to heat not being transmitted) may occur. is there.

  With reference to FIG. 2, the joining structure 200 of other embodiment according to this invention is demonstrated. The bonding structure 200 of this embodiment is different from the bonding structure 100 of the previous embodiment in that a plurality of openings O are formed in the light absorbing member 202.

  Specifically, the light-absorbing member 202 has a top wall 218 connected to the upper end portion of the peripheral wall 208, and a plurality of slits 220 extending in the same direction are formed in the top wall 218 to open the opening O. Is partitioned. The top wall 218 regulates the deformation of the light transmissive member 206 when an external impact or load is applied to the upper surface of the light transmissive member 206, so that the light transmissive member 206 and the welded portions 204 and 214 are damaged. Can be prevented. Furthermore, since the top wall 218 acts like a beam, the peripheral wall 208 of the light absorbing member 202 can be reinforced.

  In addition, the concave portion 216 of the light transmissive member 206 has an effect of controlling the direction and amount of warpage of the light transmissive member 206 as described above, but in addition to this, the light transmissive member 206 and the top wall 218 have an effect. It is possible to prevent the light-receiving member 206 from contacting the top wall 218 and reducing the negative pressure receiving area when the opening O is decompressed while maintaining a gap therebetween. If the negative pressure receiving area is reduced, the light transmitting member 206 cannot be sufficiently deformed by the vacuum pressure, and the suction adhesion between the light transmitting member 206 and the light absorbing member 202 may be impaired. Also from the viewpoint of preventing this, it is preferable that the formation region of the concave portion 216 formed in the light transmissive member 206 is 50% or more of the inner region of the annular welded portion 104.

  Also in the joint structure 200 of the present embodiment, the annular welded portion 204 has an area of a portion on the light transmissive member 206 side, as viewed in a vertical cross section with respect to the extending direction, as in the joint structure 100 of the previous embodiment. The ratio of the area S2 of the portion on the light absorbing member 202 side to S1 is in the range of 12 to 35, and more preferably in the range of 19 to 26.

  With reference to FIG. 3, the joining structure 300 of other embodiment according to this invention is demonstrated. In the bonded structure 300 of this embodiment, the inside of the opening O is in a reduced pressure state before the annular welded portion 304 is formed at a position outside the annular welded portion 304 of the light transmitting member 306. The joint structure 100, 200 of the previous embodiment is different in that a thin piece 324 is provided that is deformed and closely contacts the upper end surface of the peripheral wall 308 of the light absorbing member 302. Thereby, when the light transmissive member 306 is superposed on the light absorptive member 302, even when there is a gap between the upper end surface of the peripheral wall 308 of the light absorptive member 302 and the light transmissive member 306, When the inside of the opening O is depressurized through the suction opening 312, the thin piece 324 of the light transmissive member 306 can be brought into close contact with the upper end surface of the peripheral wall 308 of the light absorbing member 302, thereby preventing vacuum breakage due to air leakage. Therefore, it is possible to obtain excellent suction adhesion between the light transmitting member 306 and the light absorbing member 302.

  In order to make this more reliable, the thin piece 324 is deformed when the inside of the opening O is reduced to −80 kPa or more and −20 kPa or less by gauge pressure in a state before the annular welded portion 304 is formed, It is preferable that it is formed in a thickness that exhibits easy deformability to be in close contact with the light absorbing member 302. Specifically, in order to ensure adhesion by sufficient deformation, the thickness of the thin piece is preferably 0.005 mm to 0.2 mm, and 0.01 mm to 0.1 mm in consideration of formability. Is more preferable.

  In the example shown in FIG. 3, the thin piece 324 is formed horizontally along the upper end surface of the peripheral wall 308 of the light absorbing member 302 from the lower end of the peripheral portion of the light transmitting member 306, but is not limited thereto. As shown in FIG. 4A, the light-transmitting member 306 may be hung from the lower end of the peripheral portion along the outer peripheral surface of the peripheral wall 308. Alternatively, as shown in FIG. An annular groove 326 may be formed on the upper end surface of the peripheral wall 308, and the thin piece 324 may be suspended from the lower surface of the light transmitting member 306 and inserted into the annular groove 326.

  Also in the joint structure 300 of the present embodiment, the annular welded portion 304 is a portion on the light transmitting member 306 side as seen in the vertical cross section with respect to the extending direction, as in the joint structures 100 and 200 of the previous embodiment. The ratio of the area S2 of the portion on the light absorbing member 302 side to the area S1 is in the range of 12 to 35, and more preferably in the range of 19 to 26.

  Next, with reference to FIGS. 5-9, the manufacturing method of the junction structure of one Embodiment according to this invention is demonstrated. Here, the method for manufacturing the joint structure 100 shown in FIG. 1 will be described as an example, but this manufacturing method is also applied to the case of manufacturing the joint structures 200 and 300 shown in FIGS. can do.

  First, the first step is a member preparation step. In this step, the light absorbing member 102 and the light transmissive member 106 are prepared. The material and basic structure of the light absorbing member 102 and the light transmissive member 106 are the same as those described with reference to FIG.

  5A and 5B show the light-absorbing member 102 before joining to the light-transmitting member 106, where FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along line DD in FIG. . As shown in this figure, an annular groove 130 is formed in advance on the upper end surface of the peripheral wall 108 of the light-absorbing member 102 (the surface that comes into contact with the light-transmitting member 106), where the annular welded portion 104 is to be formed. Keep it. The width of the annular groove 130 is preferably set to be larger than the diameter of the laser beam applied thereto, and is preferably set to 0.1 mm to 3 mm, for example. When the width of the annular groove 130 is less than 0.1 mm, the width of the annular welded portion 104 formed therein cannot be sufficiently secured, and the welding strength is reduced. There is a possibility that dust may permeate and the airtightness performance cannot be maintained. On the other hand, when the width of the annular groove 130 exceeds 3 mm, parts other than the annular welded portion 104 are deformed due to heat at the time of welding, or due to thermal contraction when the annular welded portion 104 is solidified. Excessive strain may remain on the parts and cause deformation. Further, the depth of the annular groove 130 (distance from the boundary surface F to the groove bottom) is preferably L / 20 (mm) or more and L (mm) or less, where the width of the annular groove 130 is L (mm). In this way, as will be described later with reference to FIG. 8, the molten pool generated at the bottom of the groove by the laser light irradiation to the annular groove 130 can be sufficiently expanded, and the heat can be sufficiently reduced. It can be transmitted to the light transmissive member 106, and a good welded portion 104 can be formed. Furthermore, the depth of the annular groove 130 is preferably L / 10 (mm) or more and L / 3 (mm) or less from the viewpoint of ensuring the strength and airtightness of the welded portion 104. For example, the annular groove 130 can have a groove width L of 0.3 mm and a groove depth of 0.05 (= L / 6) mm. If the depth of the welded portion 130 is less than L / 20 (mm) and is too shallow, the expanded molten pool comes into contact with the light transmissive member 106 and heats immediately after the laser beam is irradiated onto the groove bottom of the annular groove 130. And the molten pool cannot be sufficiently spread in the lateral direction, resulting in poor welding (part of the annular groove 130 may remain). If the depth of the welded portion 130 exceeds L (mm) and is too deep, the molten pool generated at the groove bottom of the annular groove 130 expands, but cannot reach the light-transmitting member 106, and carbonization accompanying burning on the spot Discoloration may occur, resulting in poor welding. In the illustrated example, the annular groove 130 has a rectangular cross-sectional shape, but may have a semicircular shape or a semielliptical shape. Further, at least one communication groove 132 (four corresponding to each side in the illustrated example) that communicates the annular groove 130 and the inside of the opening O is formed in advance on the upper end surface of the peripheral wall 108.

  The second process is an arrangement process in which the light transmissive member 106 is disposed on the light absorbing member 102 so as to cover the opening O as shown in FIG.

  The third step is a suction contact step in which the light absorbing member 102 and the light transmissive member 106 that are superposed on each other are sucked into close contact, and this suction close contact is performed by decompressing the inside of the opening O. As shown in the left diagram of FIG. 6B, the light transmitting member 106 is overlapped with the light absorbing member 102, and the light transmitting member 106 and the light absorbing member 102 are transmitted with light. There is a case where a gap is generated due to warpage at the time of molding of the transparent member 106 or thermal deformation at the time of welding by laser light to be described later. However, since the light transmissive member 106 is formed in a thin plate shape, FIG. As shown in the right diagram of FIG. 4, by reducing the pressure in the opening O, the peripheral edge of the light transmissive member 106 can be deformed so as to be drawn toward the upper end surface of the peripheral wall 108 and can be brought into close contact with the upper end surface.

  Specifically, the pressure reduction in the opening O can be performed through a suction opening 112 formed in advance in the light-absorbing member 102 using an external pressure adjusting device D as shown in FIG.

  The pressure adjusting device D mainly includes a pressure reducing device D1, a pressurizing device D2, a controller D3, and a double pipe P connected to the suction opening 112.

  The decompression device D1 has a vacuum pump for sucking and exhausting the air in the opening O and an electric leak valve (not shown). A pressure sensor PG1 is provided in the suction line L1 of the decompression device D1, thereby detecting the pressure in the opening O during decompression.

  The pressurizing device D2 has a pressurizing tank and a supply valve for supplying a purge gas made of air or an inert gas such as nitrogen or argon (not shown). A pressure sensor PG2 is provided in the supply line L2 of the pressurizing device D2, thereby detecting the pressure in the opening O during pressurization.

  The controller D3 is configured by a PLC (programmable logic controller), a personal computer, or the like, and adjusts the opening degree of the supply valve and the leak valve. The pressure sensors PG1 and PG2 can also be connected to the controller D3, and the supply valve and the leak valve can be controlled based on the detection signals of the pressure sensors PG1 and PG2.

  The double pipe P includes a suction pipe p1 disposed on the outside and a supply pipe p2 disposed on the inside. The suction pipe p1 communicates the inside of the opening O and the pressure reducing device D1, and sucks the air in the opening O. The supply pipe p2 communicates the inside of the opening O with the pressurizing device D2, and supplies the purge gas into the opening O. Although illustration is omitted, the outer pipe of the double pipe P can be used as the supply pipe, and the inner pipe can be used as the suction pipe. However, as shown in the illustrated example, it is preferable to arrange the suction pipe p1 outside. It is preferable in that gas generated at times can be efficiently removed.

  In the fourth step, as shown in FIG. 7, the peripheral wall of the light absorbing member 102 is irradiated with the laser light LB from the light transmitting member 106 side in a state where the light absorbing member 102 and the light transmitting member 106 are in close contact with each other. Irradiate toward the upper end surface of 108 to form an annular welded portion 104 and a dotted welded portion 114 (see FIG. 1) at or near the boundary surface F between the light absorbing member 102 and the light transmissive member 106. This is a joining step for joining the light absorbing member 102 and the light transmitting member 106 together.

  Even in this joining step, the decompressed state in the opening O is continuously maintained, but it is preferable to supply a purge gas into the opening O through the supply pipe p2 at least while the annular welded portion 104 is formed. If it does in this way, the flow of air can be generated in the opening part O, and the vaporization component v of the soot and flame retardant which arise at the time of welding can be efficiently discharged | emitted and removed to the exterior through the suction piping p1.

  And in forming the welding parts 104 and 114, the dotted | punctate welding part 114 is formed first, and the cyclic | annular welding part 104 is formed after that. This is because the light-transmitting member 106 is temporarily joined to the light-absorbing member 102 by the spot-like welded portion 114 that has a relatively small heat load on the light-transmitting member 106, and then the annular shape having a relatively large heat load. This is to suppress thermal deformation of the light transmissive member 106 when the welded portion 104 is formed, and to prevent vacuum breakage due to air leakage caused by the thermal deformation. As the welding of the annular welded portion 104 progresses, the pressure receiving area of the vacuum decreases. Therefore, it is preferable to provide three or more point-like welded portions 114 that can form a plane in terms of compensating for the negative pressure. In this example, the dotted welds 114 are formed at four locations adjacent to the corners of the light transmissive member 106.

  The spot-like welded portion 114 is formed by irradiating the upper end surface of the peripheral wall 108 of the light absorbing member 102 with the laser beam LB in a state where the optical head H (FIG. 7) is stopped above the light transmitting member 106. Is done. The diameter of the dotted welded portion 114 is preferably about 0.3 to 0.7 mm, and more preferably about 0.5 mm. The annular welded portion 104 is formed by irradiating the upper end surface of the peripheral wall 108 with the laser light LB while moving the optical head H along the peripheral wall 108 of the light absorbing member 102 above the light transmitting member 106. The width of the annular welded portion 104 is preferably about 0.3 to 0.7 mm, and more preferably about 0.5 mm. As a transmitter of the laser beam LB, for example, a fiber laser (wavelength: 1070 nm), a YAG laser (wavelength: 1064 nm), a semiconductor laser (wavelength: 808 nm, 840 nm or 940 nm), a CO2 laser (wavelength: 10600 nm), etc. Can be used.

  Here, referring to FIGS. 8A to 8D, the laser beam LB is irradiated to the annular groove 130 formed in advance on the upper end surface of the peripheral wall 108 of the light-absorbing member 102, whereby the first described in FIG. A process for forming the annular welded portion 104 in which the ratio of the area S2 of the second part to the area S1 of the part is 12 to 35 will be described.

  As shown in FIG. 8A, when the light absorbing member 102 and the light transmissive member 106 are attracted and adhered to each other, the laser light is irradiated from the light transmissive member 106 side to the groove bottom of the annular groove 130. As shown in FIG. 8B, the groove bottom of the annular groove 130 generates heat and melts, and foaming is started in the molten pool. When the laser beam is subsequently irradiated, the foam grows and the molten pool grows as shown in FIG. At this time, due to the presence of the annular groove 130, the molten pool of the light absorbing member 102 does not immediately contact the light transmissive member 106, and the molten pool can be grown to a sufficient width and depth. FIG. 8D shows a state where the irradiation of the laser beam is stopped after the molten pool reaches the light transmitting member 106 and the formation of the annular welded portion 104 is completed.

  In the present embodiment, the communication groove 132 that connects the annular groove 130 and the opening O is provided on the upper end surface of the peripheral wall 108 of the light-absorbing member 102. The vaporized component v of the flame retardant is sucked and discharged into the opening O through the annular groove 130 and the communication groove 132, and finally discharged to the outside through the suction pipe p1.

  In the fifth step, after the annular welded portion 104 is formed, the decompression in the opening O is continuously held, or the inside of the opening O is pressurized, or the decompression and the pressurization are alternately performed, and unit time at that time This is an airtightness inspection process for performing an airtightness test on the annular welded portion 104 by measuring a change in the contact pressure. The pressure in the opening O is measured by the pressure sensors PG1 and PG2 shown in FIG. 7, and the change in pressure per unit time is calculated by the control unit D3 and output or displayed to the outside as necessary. it can. Or the flow rate sensor which is not shown in figure is provided in the suction line L1 or the supply line L2, and the airtightness test of the cyclic | annular welding part 104 can also be performed by measuring the change of the flow rate per unit time.

  In a sixth step (not shown), after the annular welded portion 104 is formed, the laser light LB is irradiated to the inside of the suction opening 112 or the periphery thereof from the light transmitting member 106 side while maintaining the reduced pressure in the opening O. This is a suction opening closing process for closing the suction opening 112. Thereby, the inside of the opening O can be sealed while the vacuum in the opening O is maintained. Of course, the suction opening 112 may remain open.

  According to the manufacturing method of the bonded structure of the present embodiment, the light absorbing member 102 and the light transmissive member 106 are provided by providing the light absorbing member 102 with the opening O and reducing the pressure inside the opening O. Since it is configured to suck and adhere, a conventional glass plate for press-contacting both members 102 and 106 can be eliminated, and various problems caused by the glass plate as described above can be solved. .

  Further, since the annular groove 130 is formed on the upper end surface of the peripheral wall 108 of the light absorbing member 102 and the annular groove 130 is irradiated with the laser beam LB, the annular welded portion 104 is formed. In addition to forming a weld portion 104 having a depth and a high bonding strength, the thermal effect on the light transmissive member 106 can be reduced, and thermal deformation of the light transmissive member 106 during the welding process can be suppressed. It is possible to prevent a decrease in suction adhesion due to the thermal deformation.

  Further, since the communication groove 132 that connects the annular groove 130 and the opening O is provided on the upper end surface of the peripheral wall 108 of the light-absorbing member 102, soot and flame retardant generated in the process of forming the annular welded portion 104 are provided. The vaporized component v can be sucked into the opening O through the annular groove 130 and the communication groove 132, and finally discharged to the outside through the suction pipe p1.

  Further, since the light transmissive member 106 is configured to be easily deformable as the opening O is decompressed, a gap is generated between the light transmissive member 106 and the light absorptive member 102 when they are overlapped. However, by reducing the pressure inside the opening O, the gap can be closed by the light transmissive member 106, and excellent suction adhesion can be obtained.

  Further, prior to forming the annular welded portion 104, the point-shaped welded portion 114 is formed and temporarily joined, so that the light transmitting member 106 during the annular welded portion 104 formation is formed. Thermal deformation can be suppressed, and a decrease in suction adhesion due to the thermal deformation can be prevented.

  Further, the pressure in the opening O is reduced while supplying the purge gas into the opening O, so that an air flow is generated in the opening O, and the vaporized component v of the soot and the flame retardant is efficiently generated. Can be discharged and removed.

  Further, after the annular welded portion 104 is formed, the pressure inside the opening O is continuously maintained, or the inside of the opening O is pressurized, or pressure reduction and pressurization are alternately performed. In the case where the airtightness test of the annular welded portion 104 is performed by measuring the change in flow rate, in addition to simplifying the manufacturing equipment, the manufacturing time can be greatly shortened.

  Further, the pressure in the opening O is constantly detected by the pressure sensor PG1, and based on the change in the pressure, the light absorbing member 102 and the light transmitting member 106 are brought into close contact with each other, the formation of the annular welded portion 104 is started, and the annular When it is determined that the formation of the welded portion 104 has been completed, the processing time during normal production can be shortened, and an early response can be made when an abnormality occurs.

  Although the present invention has been described based on the illustrated examples, the present invention is not limited to the above-described embodiment, and various changes and additions can be made within the scope of the claims. For example, in the manufacturing method of the bonded structure according to the above-described embodiment, the annular groove 130 having a flat groove bottom is illustrated. However, the present invention is not limited to this, and as illustrated in FIG. A raised portion 134 may be provided. Further, the number of the annular grooves 130 is not limited to one, and two annular grooves 130 may be provided adjacent to each other as shown in FIG. 9B, and may be combined at the time of welding to form one wide welding portion 104. As shown in FIG. 9C, an annular groove 136 may be provided also on the light transmitting member 106 side.

(First embodiment)
An example in which the present invention is applied to a connector will be described. FIG. 10 shows a connector as an example of the joint structure 200 of the embodiment shown in FIG. 2, (a) is a perspective view, and (b) is a cross-sectional view along the fitting direction X. . In the figure, corresponding members or portions are indicated by adding “′” to the reference numerals, and redundant description is omitted.

  This connector 200 ′ is a receptacle connector that is fixed to a substrate in an electronic device such as a portable device or an information device, and is connected to a mating connector (not shown) that is inserted along the fitting direction X, and mainly absorbs light. Covers the housing 202 ′ as the elastic member 202, the plurality of contacts 203 extending in the fitting direction X and arranged in the direction orthogonal to the fitting direction X, and the opening O ′ of the housing 202 ′. And a thin plate-like cover 206 ′ as a light transmissive member 206 that is sealed together.

  The housing 202 ′ is formed of a light-absorbing and insulating thermoplastic resin, and has a peripheral wall 208 ′ having a fitting port 212 ′ into which a mating connector is inserted, a bottom wall 210 ′, and a top wall 218. 'And have.

  A plurality of slits 220 ′ formed along the fitting direction X are formed in the top wall 218 ′ of the housing 202 ′, and an opening O ′ is defined by the slits 220 ′. A contact 203 is disposed in each slit 220 '. The front end portion of each contact 203 protrudes downward from the inner surface of the top wall 218 'for connection with the mating connector, and the rear end portion thereof protrudes from the housing 202' for connection with the substrate of the electronic device or other wiring board. Exposed.

  The cover 206 ′ is overlapped with the housing 202 ′ so as to cover the opening O ′ of the housing 202 ′, and the peripheral wall 208 is interposed through an annular welded portion 204 ′ formed so as to surround all the slits 220 ′. It is joined to the upper end surface of 'over the entire circumference. As a result, the water, dust, and water immersion routes from the fitting port 212 ′ to the inside of the electronic device through the slit 220 ′ are blocked by the cover 206 ′ and the annular welded portion 204 ′. Further, on the outside of the annular welded portion 204 ′, four dotted welded portions 214 ′ are formed adjacent to the corner portion of the cover 206 ′.

  In the connector 200 ′, the annular welded portion 204 ′ has a ratio of the area S2 ′ of the portion on the housing 202 ′ side to the area S1 ′ of the portion on the cover 206 ′ side in the vertical cross section with respect to the extending direction of 12 to 35. More preferably, it is in the range of 19 to 26.

  Such a connector 200 ′ can be manufactured according to the manufacturing method of the embodiment described with reference to FIGS. 5 to 8 with the fitting port 212 ′ as the suction opening 212.

(Second embodiment)
An example in which the present invention is applied to a sensor will be described. 11A and 11B show a sensor as an example of the joint structure 300 according to the embodiment shown in FIG. 4A. FIG. 11A is a perspective view and FIG. 11B is a cross-sectional view.

  The sensor 300 ′ can be any type of sensor such as an acceleration sensor, a vibration sensor, an angular velocity sensor, a distance sensor, and a position sensor. The sensor 300 ′ mainly includes a housing 302 ′ as a light absorbing member 302 and a cover 306 ′ as a light transmissive member 306 that covers and seals the opening O ′ of the housing 302 ′. Yes, a detector main body (sensor chip) (not shown) is accommodated in the housing 302 ′.

  The casing 302 ′ is made of a light-absorbing thermoplastic resin, and includes a peripheral wall 308 ′ that partitions the opening O ′ and projects a suction cylinder 312 ′ toward the front, and a bottom wall 310 ′. Have.

  The cover 306 ′ is placed on the peripheral wall 308 ′ of the housing 302 ′ so as to cover the opening O ′ of the housing 302 ′, and is entirely surrounded by the dotted welded portion 314 ′ and the annular welded portion 304 ′. It is joined over. A thin piece 324 'is suspended from the peripheral edge of the cover 306' along the outer surface of the peripheral wall 308 '. The thin piece 324 'is formed so as to be attracted and brought into close contact with the peripheral wall 308' when the inside of the opening O 'is decompressed through the suction cylinder 312'.

  In the sensor 300 ′, the annular welded portion 304 ′ has a ratio of the area S2 ′ of the portion on the housing 302 ′ side to the area S1 ′ of the portion on the cover 306 ′ side as viewed in a vertical cross section with respect to the extending direction thereof. It is in the range of 35, more preferably in the range of 19 to 26.

  Such a sensor 300 ′ can be manufactured according to the manufacturing method of the embodiment described with reference to FIGS. 5 to 8 with the suction cylinder 312 ′ as the suction opening 312.

  Although the base end of the suction cylinder 312 ′ remains open, the reduced pressure in the opening O ′ is maintained after the formation of the annular weld 304 ′ in accordance with the sixth step of the manufacturing method described above. In this state, the opening of the proximal end portion of the suction tube 312 ′ may be closed by irradiating laser light from the cover 306 ′ side around the opening of the proximal end portion of the suction tube 312 ′. Thereby, the internal space of the sensor 300 ′ can be sealed while being kept in a vacuum.

  Thus, according to the present invention, it is possible to provide a joining structure suitable for uniformly and reliably bringing members to be joined together without using a glass plate, and joining them without using a glass plate. It is possible to provide a method for manufacturing a bonded structure that can uniformly and reliably bring the members to be bonded together.

100, 200, 300 Joined structure 102, 202, 302 Light absorbing member 104, 204, 304 Annular welded portion 106, 206, 306 Light transmitting member 108, 208, 308 Peripheral wall 112, 212, 312 Suction opening 114, 214, 314 Spot welded portion 130 Annular groove 132 Communication groove 324 Thin piece D Pressure adjusting device D1 Pressure reducing device D2 Pressure device D3 Controller F Interface H Optical head L1 Suction line L2 Supply line O Opening portion PG1, PG2 Pressure Sensor S1 Area of the first portion (light transmissive member side) of the annular welded portion S2 Area of the second portion (light absorbent member side) of the annular welded portion

Claims (3)

A light absorbing member having at least one opening;
A light transmissive member disposed on the light absorbing member so as to cover the opening,
An annular welded portion that extends so as to surround the opening and joins the light absorbing member and the light transmissive member is formed,
The annular welded portion has a ratio of the area of the light-absorbing member side portion to the area of the light-transmitting member side portion in a range of 12 to 35, as viewed in a vertical cross section with respect to the extending direction,
The light transmissive member is formed in a thin plate shape that is deformed when the inside of the opening is in a reduced pressure state before the annular welded portion is formed and is in close contact with the light absorbing member. ,
The light absorbing member has a peripheral wall and a top wall connected to the upper end of the peripheral wall, and the top wall has a plurality of slits extending in the same direction as the opening . A bonded structure characterized by the above.   The said structure exists in the range of 19-26, The joining structure of Claim 1 characterized by the above-mentioned. Located adjacent to the welded portion of the annular joint structure according to claim 1 or 2, characterized in that it comprises the light-absorbing member and the light transmitting member and the point-like welding portion joining the .

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