Method and apparatus for laser bonding of optical component unit

The present invention relates to a laser joining method and an apparatus of an optical component unit for fixing an optical component housed along an inner wall of a housed component formed of resin to the inner wall.

As a conventional method of fixing an optical component to a thermoplastic resin accommodating component, a narrowing margin is provided in a mechanism for accommodating the optical component of the accommodating component, and the accommodating component is fixed to a jig and added with a so-called anvil. There is a fixing method using a thermal throttle that fixes the optical component to the accommodating component by deforming the throttle margin with heat and pressure. Alternatively, a fixing method is known in which an optical component is adhered to a housing component using an ultraviolet curable adhesive.

In general, when accuracy is not so required, a fixing method using heat strangulation is often adopted, and when accuracy is required, a fixing method using an ultraviolet curable adhesive is often adopted. By the way, conventionally, it has been considered that it is very difficult to join glass and resin by a laser welding method. However, for example, as described in Patent Document 1, it has recently become possible to bond glass and resin using a laser. In this method, the resin is locally hot-melted by a laser to create a viscous flow state, so that the resin can be pushed between the optical component and the resin housing component.<patcit num="1"><text>Japanese Patent Application 2003-130688</text></patcit>

<p> In the fixing method using heat strangulation described above, a dedicated anvil and receiving jig are required for each model for optical parts and accommodating parts, and the anvil and receiving jig are remade and the receiving jig is remade according to the model change. Position adjustment is required.</p><p> For this reason, with the conventional technology, it takes a long time to switch the model to be manufactured and start up, so it is necessary to have micron-order accuracy for fixing the optical component and the housing component, and there are many models for the optical component and the housing component. There is a problem that productivity is lowered when the model switching cycle is short in the manufacturing process.</p><p> On the other hand, in the above-mentioned fixing method using an ultraviolet curable adhesive, the position of the optical component is adjusted in a state where the adhesive is weakly irradiated with ultraviolet rays, and then the adhesive is irradiated with ultraviolet rays until the adhesive is cured. Since it takes about 10 seconds at the earliest to cure, the tact is lowered, and there is a problem that the productivity is lowered in the case of mass production from the initial stage of production start.</p><p> Further, when a plurality of lenses are fixed to an integral storage component such as a camera lens, an adhesive enters between the lens and the receiving surface in the optical axis direction, so that the lens is displaced in the optical axis direction. Depending on the situation, the distance between lenses may change, causing defects.</p><p> Further, in the case of an optical component unit that requires a certain level of pull-out resistance of the optical component, there is also a problem that sufficient pull-out resistance cannot be obtained if the adhesive can be applied only to the side surface of the optical component.</p><p> The reason why joining glass and resin in the conventional laser welding method has been considered to be very difficult is as follows. Laser welding is based on the premise that atomic bonds and chemical bonds are possible. When metal is bonded to each other, the bond between atoms affects the bonding strength, and when resin is bonded to each other. In many cases, the chemical bond affects the bond strength.</p><p> However, when glass and resin are bonded, they can only be bonded by physical bonds such as the anchor effect, so the bonding strength is about two orders of magnitude compared to the bonds between atoms and chemical bonds. It becomes smaller. Therefore, when joining glass and resin, it is necessary to increase the joining area. In order to increase the joint area, the resin must be filled as much as possible in the place where the resin and the glass can be joined. However, since the resin in the viscous flow state lacks the property of moving due to the capillary phenomenon, it is not possible to sufficiently fill the place where the resin and the glass can be a joint.</p><p> For this reason, in the conventional method of fixing the optical component to the resin housing component using a laser, the resin constituting the inner wall is locally hot-melted to form a viscous fluid state, and the gravitational force on the hot-melted resin is exerted. The action pushes the resin into the gap between the optical component and the inner wall.</p><p> However, especially in the case of an optical component unit whose height from the optical component of the inner wall is 1 mm or less, using a normal spot beam or a line beam with a beam width of about 600 μm not only melts the entire inner wall, but also makes it more than the upper surface of the inner wall. The melting marks swell and interfere with other parts.</p><p> In addition, the receiving surface of the housing component facing the lower surface of the optical component is irradiated with a laser, and the decomposition gas of the resin adheres to the surface of the lower surface of the optical component, or unevenness occurs when the surface of the receiving surface is melted and solidified. In addition, fluctuations in the distance between optical components may cause deterioration of characteristics.</p><p> An object of the present invention is an optical component unit capable of shortening the start-up time when switching models, preventing decomposition gas from adhering to the lower surface of the optical component, and preventing unevenness on the surface of the receiving surface of the accommodating component. To provide a laser bonding method and apparatus for the above.</p>

<p> The laser bonding method of the optical component unit according to the present invention is a laser bonding method of the optical component unit for fixing the optical component accommodated along the inner wall of the housing component formed of the resin to the inner wall, and is a laser bonding method of the optical component unit by the laser irradiation means. A laser line beam whose long side is in the direction along the inner wall is irradiated to the inner wall while moving in the long side direction, and the resin of the laser irradiation portion is brought into a viscous flow state by local thermal melting, and this viscous flow state is achieved. The resin is pressed between the optical component and the inner wall.</p><p> The laser joining device for the optical component unit according to the present invention is a laser joining device for optical components that fixes an optical component to be accommodated along an inner wall of an accommodation component formed of resin to the inner wall, and accommodates the optical component. The inner wall is irradiated while the holding member for holding the housing component and the laser line beam whose long side is in the direction along the inner wall are moved in the long side direction, and the resin of the laser irradiation part is locally heat-melted. It is characterized in that it is provided with a laser irradiation means that is in a viscous flow state and that pushes the resin in this viscous flow state between the optical component and the inner wall.</p><p> The optical component unit according to the present invention is an optical component unit including an accommodation component formed of a resin and an optical component accommodated along an inner wall of the accommodation component, and the top end of the inner wall from the optical component. The height is 1 mm or less, and the inner wall of the accommodating part has a melting mark, and the melting mark is formed by a resin obtained by locally heat-melting the inner wall into a viscous flow state between the optical component and the inner wall. When it is pushed in, the swelling from the inner wall is 0.1 mm or less, and the distance from the optical component to the top of the inner wall is 1 mm or less, the swelling is not seen under any conditions if the beam width is 300 μm or less. If it is 1 mm or more, it will not rise even if it is not a line beam.</p>

<p> As described above, according to the present invention, it is possible to deal with various products, the decomposition gas of the resin does not adhere to the surface of the optical component, and the distance between lenses due to the unevenness generated on the receiving surface of the optical component The defect of fluctuation can be prevented.</p>

The laser bonding method of the optical component unit according to the present embodiment is a laser bonding method of the optical component unit for fixing the optical component accommodated along the inner wall of the housing component formed of the resin to the inner wall, and laser irradiation. By means, a laser line beam whose long side is in the direction along the inner wall is irradiated to the inner wall while moving in the long side direction, and the resin of the laser irradiation part is brought into a viscous flow state by local thermal melting, and this viscosity is achieved. The flowing resin is pushed between the optical component and the inner wall.

At this time, since the short sides of the laser line beam face each other in the direction perpendicular to the moving direction of the laser line beam, the melting mark (width of the melting portion) becomes smaller, and the melting mark rises above the upper surface of the inner wall and interferes with other parts. There is nothing to do.

Further, the receiving surface of the accommodating component facing the lower surface of the optical component is not irradiated with the laser by the laser line beam, and the decomposition gas of the resin does not adhere to the surface of the lower surface of the optical component. Therefore, unlike the conventional case, when the surface of the receiving surface of the accommodating component is melted and solidified, unevenness is generated, and the distance between the optical components is not deteriorated due to the fluctuation of the distance between the optical components. It is possible to obtain high precision and high pull-out resistance in fixing parts.

In terms of tact, by moving the laser line beam in the long side direction, the time for hot-melting the resin over the required length of the inner wall can be shortened. In this method of irradiating the laser line beam, the optical component can be fixed along the inner wall of the housing component without using a special jig. As a result, the start-up time when switching models can be shortened.

The laser line beam irradiating the inner wall preferably has a beam width of 300 μm or less. This is effective when irradiating a housing component with a height of 0.5 mm from the optical component to the upper surface of the inner wall with a laser power that can obtain sufficient penetration resistance, and the beam width should be 300 μm or less. As a result, the melting mark (width of the melting part) becomes smaller, and the melting mark does not rise above the upper surface of the inner wall and interfere with other parts. Further, the receiving surface of the accommodating component facing the lower surface of the optical component is not irradiated with the laser, and the decomposition gas of the resin does not adhere to the surface of the lower surface of the optical component. Further, the distance between the optical components does not fluctuate due to the unevenness generated when the surface of the receiving surface of the accommodating component is melted and solidified, and the characteristics are not deteriorated.

The optical component is preferably a lens made of glass. The lens is preferably a convex lens. The housing component preferably has a cylindrical shape or a shape obtained by omitting a part of the cylindrical shape.

The laser bonding device for optical components according to the present embodiment is a laser bonding device for optical components that fixes an optical component to be accommodated along an inner wall of an accommodation component formed of resin to the inner wall, and the optical component is attached to the optical component. The holding member for holding the housed parts and the laser line beam whose long side is in the direction along the inner wall are moved in the long side direction to irradiate the inner wall and locally heat-melt the resin of the laser irradiation part. It is provided with a laser irradiation means for pushing the resin in the viscous flow state between the optical component and the inner wall.

With the above configuration, the direction perpendicular to the moving direction of the laser beam is on the short side side of the line beam, so that the melting mark (width of the melting part) becomes smaller, and the melting mark rises above the upper surface of the inner wall and becomes different from other parts. There is no interference. Further, the receiving surface of the accommodating component facing the lower surface of the optical component is not irradiated with the laser, and the decomposition gas of the resin does not adhere to the surface of the lower surface of the optical component.

Further, unlike the conventional case, when the surface of the receiving surface is melted and solidified, unevenness is generated and the characteristics are not deteriorated due to the fluctuation of the distance between the optical components, and the optical components requiring fixing accuracy are fixed. It is possible to obtain high precision and high pull-out resistance.

In terms of tact, by moving the laser line beam in the long side direction, the time for hot-melting the resin over the required length of the inner wall can be shortened. In this method of irradiating the laser line beam, the optical component can be fixed along the inner wall of the housing component without using a special jig. As a result, the start-up time when switching models can be shortened.

The laser irradiation means preferably has a laser light source provided for emitting the laser and a condensing optical system for condensing the laser emitted from the laser light source on the inner wall of the accommodating component.

The condensing optical system is preferably an aspherical lens. The condensing optical system preferably includes two convex lenses facing the mask. The laser bonding device for optical components of the present invention preferably includes an irradiation position moving device for moving the laser irradiation means in order to change the position of the inner wall for irradiating the laser.

In the irradiation position moving device, it is preferable that the laser irradiation means is rotationally moved along the circumferential direction of the inner wall of the accommodating component. The housing component preferably has a cylindrical shape or a shape obtained by omitting a part of the cylindrical shape.

The optical component unit according to the present embodiment is an optical component unit including an accommodation component formed of resin and an optical component accommodated along an inner wall of the accommodation component, and the optical component is described as described above. The height to the top of the inner wall is 1 mm or less, and the inner wall of the accommodating part has a melting mark, and the melting mark is a resin obtained by locally heat-melting the inner wall into a viscous flow state. It is pushed in between the two, the swelling from the inner wall is 0.1 mm or less, and there is no melting mark on the optical component receiving surface of the accommodating component.

With the above configuration, it has high accuracy and high pull-out resistance in fixing optical parts that require fixing accuracy. Since the optical component unit according to the present embodiment is manufactured by the optical component fixing device according to the present embodiment, the optical component can be fixed along the inner wall of the accommodating component without using a special jig. .. As a result, the start-up at the time of model switching can be shortened.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a schematic view showing a configuration of an optical component fixing device 100 according to the present embodiment. The optical component fixing device 100, which forms a laser bonding device for optical components, includes a holding member 9 that holds the accommodating component 5 in which the convex lens 8 forming the optical component is housed.

The housing part 5 has a cylindrical shape in which the inner wall 6 is formed, and is formed of a material in which carbon black is mixed with polycarbonate. The convex lens 8 is held along the inner wall 6 formed in the housing component 5.

The optical component fixing device 100 is provided with a laser irradiation device 1, and the laser irradiation device 1 has a condensing optical system 2 and a laser light source 3. The laser light source 3 irradiates the laser 11 having a wavelength of 810 nm, which can bring the resin constituting the inner wall 6 formed in the housing component 5 into a viscous flow state and a state in which decomposition occurs locally. The focusing optical system 2 uses the laser 11 emitted from the laser light source 3 as a laser line beam having a beam width of 300 μm or less on the inner wall 6 of the housing component 5, and is compact and lightweight because it is a single aspherical lens. Therefore, it is preferable. The condensing optical system 2 has no particular problem even if a combination of a plurality of convex lenses, concave lenses, or aspherical lenses is capable of condensing light to a beam width of 300 μm or less.

The optical component fixing device 100 includes a condensing optical system driving device 10, and the condensing optical system driving device 10 adjusts the position of the condensing optical system 2 and the position of the condensing optical system 2 by tilting the condensing optical system 2 with the xyz direction. It is provided to adjust the tilt.

Further, the optical component fixing device 100 is provided with an irradiation position moving device 4 for rotating and moving the laser irradiation device 1 around the axis of the convex lens 8 housed in the housing component 5, and the laser by the irradiation position moving device 4 is provided. By rotating the irradiation device 1, the position of the inner wall 6 where the laser line beam 11 irradiated from the laser irradiation light source 3 hits is moved so that the laser is irradiated to the entire circumference of the convex lens 8.

The operation of the optical component fixing device 100 will be described below. FIG. 2 is a cross-sectional view for explaining a method of fixing the convex lens 8 to the inner wall 6 of the accommodating component 5 by the optical component fixing device 100 according to the present embodiment.

First, the accommodating part 5 is fixed to the holding member 9. Then, the convex lens 8 is fitted along the inner wall 6 of the housing component 5. Next, the laser is emitted from the laser light source 3 of the laser irradiation device 1, and the laser line beam 11 transmitted through the condensing optical system 2 is directed toward the inner wall 6 so that the long side thereof is along the inner wall 6. Irradiate to. Then, the laser irradiation device 1 is rotationally moved by the irradiation position moving device 4, and the laser line beam 11 is moved in the long side direction.

The inner wall 6 of the housing component 5 irradiated with the laser line beam 11 is heated by the irradiated laser line beam 11 to soften and melt. At this time, softening / melting occurs due to heat conduction in a portion wider than the width irradiated with the laser line beam 11, and the softened / melted inner wall 6 starts to decompose locally.

Due to the reaction force 12 generated during this disassembly, a force directed in the direction of gravity acts is applied to the resin in a viscous flow state on the inner wall 6 of the accommodating component 5, and the resin acts between the convex lens 8 and the inner wall 6 of the accommodating component 5. It can be pushed into a gap of several tens of micrometers (μm). As a result, the convex lens 8 is fixed to the accommodating component 5, and the laser irradiation device 1 is rotationally moved by the irradiation position moving device 4, so that the convex lens 8 is fixed over the entire peripheral edge of the convex lens 8 in a few seconds.

At this time, since the short side (width) of the laser line beam 11 faces in the direction perpendicular to the moving direction of the laser line beam 11 and the laser line beam 11 having a beam width of 300 μm or less is irradiated, it is formed on the inner wall 6 of the housing component 5. The melting mark (width of the melting part) to be formed becomes smaller, and the melting mark does not rise above the upper surface of the inner wall 6 and interfere with other parts, and the receiving surface of the accommodating component 5 facing the lower surface of the convex lens 8 13 is not irradiated with a laser, and the decomposition gas of the resin does not adhere to the surface of the lower surface of the convex lens 8.

Furthermore, if the shapes of the housing component 5 and the convex lens 8 change due to a model change, the laser focal position and the laser irradiation position can be changed by moving the condensing optical system 2 with the condensing optical system driving device 10. To do.

As described above, according to the present embodiment, the resin constituting the inner wall 6 is locally thermally melted into a viscous flow state by irradiating the inner wall 6 with the laser line beam 11, and the reaction force generated at the time of the thermal melting is generated. Since the resin is pushed into the gap between the convex lens 8 and the inner wall 6 by the action of 12, the convex lens 8 can be fixed along the inner wall 6 of the housing component 5 without using a special jig.

Further, since there is no swelling of melting marks from the upper surface of the inner wall 6, interference with other parts does not occur, and various products can be supported. Since the receiving surface of the storage part is not irradiated with the laser, it is possible to prevent the defect that the decomposition gas of the receiving surface adheres to the back surface of the convex lens 8, and the distance between the lenses due to the occurrence of the unevenness of the melting mark on the receiving surface. It is possible to prevent the defect of fluctuation.

Further, by moving the laser line beam 11 in the long side direction, the time for thermally melting the resin over the required length of the inner wall 6 can be shortened. Further, by changing the laser focal position and the laser irradiation position by the condensing optical system driving device 10, the start-up time at the time of model switching can be shortened.

(Embodiment 2) FIG. 3 is a schematic view showing the configuration of the optical component fixing device 100 according to the present embodiment. The same components as those of the optical component fixing device 100 shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 3, the housing component 5 has a shape in which a part of the cylindrical shape forming the inner wall 6 is omitted. For example, when viewed from above, the inner wall 6 is distributed in 3 equal parts around the convex lens 8 to form the inner wall 6 and is distributed in 3 equal parts. A gap is formed between the inner wall 6 and the inner wall 6.

The optical component fixing device 100 is provided with a chuck mechanism (not shown), and the chuck mechanism has a gripping means such as a claw that operates in the gap between the inner wall 6 and the inner wall 6 which are distributed in 3 equal parts of the accommodation component 5, and is a convex lens. 8 is gripped and the position of the convex lens 8 with respect to the accommodating component 5 is adjusted with an accuracy of several μm or less. Any chuck mechanism can be applied as long as it has a mechanism for gripping the convex lens 8, and detailed description thereof will be omitted.

Three laser irradiation devices 1 each equipped with a laser light source 3 are arranged at an equal distribution of 120 °, and in the irradiation position moving device 4, the laser 11 irradiating from each laser irradiation device 1 is 1/3 of the circumference of the convex lens 8. That is, each laser irradiation device 1 is rotated and moved at the same time so that only the inner wall 6 distributed in 3 equal parts is irradiated.

The operation of the optical component fixing device 100 configured in this way will be described. First, the accommodating part 5 is fixed to the holding member 9. Then, the convex lens 8 is fitted along the inner wall 6 of the housing component 5. Next, the laser 11 is emitted from the laser light source 3 of the laser irradiation device 1, and the laser line beam 11 transmitted through the condensing optical system 2 is placed on the inner wall of the housing component 5 so that the long side thereof is in the direction along the inner wall 6. Irradiate to 6. Then, the irradiation position moving device 4 rotates and moves the plurality of laser irradiation devices 1 to move the laser line beam 11 in the long side direction.

The inner wall 6 of the housing component 5 irradiated with the laser line beam 11 is heated by the irradiated laser line beam 11 to soften and melt. At this time, softening / melting occurs due to heat conduction in a portion wider than the width irradiated with the laser line beam 11, and the softened / melted inner wall 6 starts to decompose locally.

Due to the reaction force 12 generated during this disassembly, a force directed in the direction of gravity acts is applied to the resin in a viscous flow state on the inner wall 6 of the accommodating component 5, and the resin acts between the convex lens 8 and the inner wall 6 of the accommodating component 5. It can be pushed into a gap of several tens of micrometers (μm). As a result, the convex lens 8 is fixed to the accommodating component 5, and the three laser irradiation devices 1 are simultaneously rotated by the irradiation position moving device 4, so that the fixing is performed in a few seconds.

At this time, since the short side (width) of the laser line beam 11 faces in the direction perpendicular to the moving direction of the laser line beam 11 and the laser line beam 11 having a beam width of 300 μm or less is irradiated, it is formed on the inner wall 6 of the housing component 5. The melting mark (width of the melting part) to be formed becomes smaller, and the melting mark does not rise above the upper surface of the inner wall 6 and interfere with other parts, and the receiving surface of the accommodating component 5 facing the lower surface of the convex lens 8 13 is not irradiated with a laser, and the decomposition gas of the resin does not adhere to the surface of the lower surface of the convex lens 8.

If the shapes of the housing component 5 and the convex lens 8 are changed due to a model change, the laser focal position and the laser irradiation position can be changed by moving the focusing optical system 2 by the focusing optical system driving device 10. To do.

As described above, in the present embodiment, since the laser irradiates three 120 ° equal distribution positions from the center of the convex lens 8 at the same time, it is possible to alleviate the misalignment and residual stress due to thermal deformation, and the accuracy is high. Lens fixation can be realized. Moreover, since the laser line beam 11 is irradiated at three points at the same time, the processing tact can be halved. Further, since there is no swelling of melting marks from the upper surface of the inner wall 6, interference with other parts does not occur, and various products can be supported. Further, since there is no melting mark on the receiving surface 13, it is possible to prevent the decomposition gas of the receiving surface 13 from adhering to the back surface of the convex lens 8. Further, it is possible to prevent the defect of the fluctuation of the distance between the lenses due to the occurrence of unevenness due to the laser irradiation of the receiving surface 13.

(Embodiment 3) As shown in FIG. 4, in the present embodiment, as shown in FIG. 4, the beam width of the laser emitted from the laser light source 3 is applied to the inner wall 6 of the housing component 5 by the condensing optical system 2 composed of two sets of convex lenses. It is the same as that of the second embodiment except that it is irradiated as a focused laser line beam 11 having a thickness of 300 μm or less.

When the beam width is made smaller, the mask 14 may be installed behind the condensing optical system 2. Also in this embodiment, since the laser irradiates three 120 ° equal distribution positions from the center of the convex lens 8 at the same time, it is possible to alleviate the positional deviation and residual stress due to thermal deformation, and realize highly accurate lens fixing. can do. Moreover, since the laser line beam 11 is irradiated at three points at the same time, the processing tact can be halved. Further, since there is no swelling of melting marks from the upper surface of the inner wall 6, interference with other parts does not occur, and various products can be supported. Further, since there is no melting mark on the receiving surface 13, it is possible to prevent the decomposition gas of the receiving surface 13 from adhering to the back surface of the convex lens 8. Further, it is possible to prevent the defect of the fluctuation of the distance between the lenses due to the occurrence of unevenness due to the laser irradiation of the receiving surface 13.

As described above, in the present invention, the melting mark does not rise from the upper surface of the inner wall, and there is no defect that it interferes with other parts, so that the cost is low, the productivity is improved, and the start-up time at the time of model switching is short. Since the productivity is improved, it can be used for a laser bonding method of an optical component unit, a laser bonding device of an optical component unit, and an optical component unit.

<figref num="1">Schematic diagram showing the configuration of the optical component fixing device according to the first embodiment of the present invention.</figref><figref num="2">Cross-sectional view for explaining a method of fixing an optical component to an inner wall of a housing component by the optical component fixing device.</figref><figref num="3">Schematic diagram showing the configuration of the optical component fixing device according to the second embodiment of the present invention.</figref><figref num="4">Schematic diagram showing the configuration of the optical component fixing device according to the third embodiment of the present invention.</figref>

Code description

1 Laser irradiation device 2 Condensing optical system 3 Laser light source 4 Irradiation position moving device 5 Containing parts 6 Inner wall 7 Resin 8 Convex lens 9 Holding member 10 Condensing optical system driving device 11 Laser 12 Reaction force 13 Receiving surface 14 Mask 100 Optical parts fixing apparatus