JP2007219337A - Method of adhesion and fixing of optical component and laser light source apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of adhesion and fixing of an optical component by which the shift of an optical axis due to the contraction by hardening of an ultraviolet setting type adhesive is suppressed and an optical axis is adjusted while laser light is being emitted. <P>SOLUTION: The method of adhesion and fixing of the optical component is to bond and fix optical component (lens unit) 13 on a substrate 11 on which a laser light source (semiconductor laser) 12 is installed by using an ultraviolet-setting adhesive 19, and includes: a process in which the optical axis position of the optical component 13 is adjusted with respect to the laser light source 12; a process in which an ultraviolet-setting adhesive 19 is applied on the two different faces 14a and 14b of a transparent support body 14 which are bonded to the optical component 13 and the substrate 11, respectively, and the transparent body 14 is made to contact the optical component 13 and the substrate 11 and arranged; and a process in which the ultraviolet-setting adhesive 19 applied on the above two faces 14a and 14b is simultaneously hardened by irradiating the support body with an ultraviolet ray. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical component adhesive fixing method and a laser light source device, in which optical components such as lenses and mirrors in a laser optical system are bonded and fixed on a substrate using an ultraviolet curable adhesive.

  Conventionally, an ultraviolet curable adhesive, a thermosetting adhesive, solder, welding, or the like is used for bonding and fixing optical components to a substrate in a laser optical system. Above all, when fixing the lenses and mirrors that require optical axis adjustment, they are not cured until they are irradiated with ultraviolet rays, and after the optical axis adjustment, they are cured instantaneously by irradiating ultraviolet rays without moving from that state. UV curable adhesives that can be used are generally widely used (see, for example, Patent Document 1 below).

  FIG. 7 is a side cross-sectional view of a main part of a laser light source device for explaining a conventional adhesive fixing method using an ultraviolet curable adhesive. A semiconductor laser 1 as a laser light source is fixed to a fitting hole 2 a provided in a holding member 2. Since the light beam emitted from the semiconductor laser 1 is a divergent light beam, the coupling lens 3 as an optical component is arranged so that the light beam becomes a substantially parallel light beam with its focal point aligned with the emission point of the semiconductor laser 1. ing. The coupling lens 3 is bonded and fixed via an ultraviolet curable adhesive 4 on a protrusion 2b that protrudes from the holding member 2 and has a cylindrical bonding surface formed along the periphery of the lens.

The coupling and fixing of the coupling lens 3 to the holding member 2 is performed according to the following procedure.
First, the semiconductor laser 1 is fixed to the fitting hole 2a of the holding member 2, and the optical axis 5 is determined. Next, an ultraviolet curable adhesive 4 is applied on the protrusion 2 b of the holding member 2. Next, the coupling lens 3 is held by an alignment clamp device (not shown) and placed on the protrusion 2b. Then, with the semiconductor laser 1 turned on, the position of the coupling lens 3 is adjusted to match the optical axis 5 of the semiconductor laser 1. Finally, after the ultraviolet curable adhesive 4 is irradiated with ultraviolet rays and cured, the clamping force by the alignment clamp device is released. As described above, the coupling lens 3 is bonded and fixed onto the protrusion 2b.

JP 2002-31773 A

  In such a conventional adhesive fixing method, it is necessary to thicken the layer of the ultraviolet curable adhesive 4 applied on the protrusion 2b of the holding member 2 in consideration of the optical axis adjustment range of the coupling lens 3. . However, when the layer thickness of the adhesive 4 is increased, the curing shrinkage of the adhesive 4 also increases, so that there is a problem that the optical axis shift of the coupling lens 3 is likely to occur.

  Also, this type of laser light source device is a blue (wavelength 445 nm) semiconductor laser or green (wavelength 532 nm) SHG (second harmonic generation) solid state laser used for a display light source, or a blue-violet color used for a data storage light source. (Wavelength 405 nm) In some cases, the present invention is applied to a laser optical system such as a semiconductor laser. In this case, when the optical axis of the optical component is adjusted by turning on the laser beam, the photopolymerization initiator of the ultraviolet curable adhesive reacts and cures with the laser beam, and the optical axis cannot be adjusted smoothly. There was a problem.

  The present invention has been made in view of the above-mentioned problems, and can suppress optical axis shift due to curing shrinkage of an ultraviolet curable adhesive, and can perform optical axis adjustment while turning on laser light, and an optical component adhesive fixing method and laser light source It is an object to provide an apparatus.

In solving the above problems, the optical component adhesive fixing method of the present invention is an optical component adhesive fixing method in which an optical component is bonded onto a substrate on which a laser light source is installed using an ultraviolet curable adhesive. There,
Adjusting the optical axis position of the optical component with respect to the laser light source;
Placing a transparent support having a UV curable adhesive applied to two different surfaces respectively bonded to the optical component and the substrate, in contact with the optical component and the substrate, respectively;
And irradiating the support with ultraviolet rays to simultaneously cure the ultraviolet curable adhesive applied to the two surfaces.

  According to another aspect of the present invention, there is provided a laser light source device including: a laser light source; a substrate on which the laser light source is installed; and an optical component installed on the substrate with the laser light source and the optical axis aligned. A transparent support having a first adhesive surface bonded to the substrate and a second adhesive surface bonded to the substrate, and the optical component has an ultraviolet curable adhesive on the first and second adhesive surfaces with respect to the substrate. Is bonded and fixed through the above-mentioned support to which is applied.

  In the present invention, after adjusting the optical axis of the optical component with respect to the laser light source, an ultraviolet curable adhesive is applied to the first and second different bonding surfaces respectively bonded to the optical component and the substrate. A transparent support is placed on the substrate and irradiated with ultraviolet rays to simultaneously cure the ultraviolet curable adhesive on each side.

  At this time, the ultraviolet curable adhesive applied to each surface of the support causes the support to be guided and disposed at an appropriate bonding position with respect to the optical component and the substrate by a sticking phenomenon due to surface tension. Then, by simultaneously curing the UV curable adhesive applied to each surface of the support, the shrinkage of the adhesive on each surface is absorbed by the relative movement of the support with respect to the optical component and the substrate, and after the adhesive is cured The optical axis shift of the optical component is suppressed.

  Therefore, it is possible to adjust the optical axis position of the optical component without increasing the coating thickness of the ultraviolet curable adhesive, so that it is possible to effectively suppress the displacement of the optical component due to the curing shrinkage of the adhesive. Further, since the bonding is performed after the optical axis position of the optical component is adjusted, even when a short wavelength laser light source having a wavelength of 550 nm or less is used as the laser light source, the optical component and the substrate in a state where the laser light is turned on. Can be fixed.

  The support may be any material that is transparent to ultraviolet rays, such as glass or plastic. It is preferable that the surface (first and second adhesive surfaces) to which the ultraviolet curable adhesive is applied is mirror-finished to control the surface roughness. Thereby, the surface tension by the ultraviolet curable adhesive can be effectively expressed.

  The viscosity of the ultraviolet curable adhesive is preferably as low as possible, and preferably, the viscosity in an uncured state is less than 1600 mPa · s. This is because, when the viscosity exceeds 1600 mPa · s, the viscosity is too high and it is difficult to induce and displace (move) the support based on the surface tension of the adhesive.

  The two surfaces (first and second adhesive surfaces) of the support to which the ultraviolet adhesive is applied are not particularly limited, but are preferably two surfaces orthogonal to each other. With this configuration, the optical component is placed in the X-axis direction (optical axis direction), the Y-axis direction (horizontal direction orthogonal to the optical axis), and the Z-axis direction (height direction orthogonal to the optical axis) with respect to the optical axis of the laser light source. It is possible to adjust in each direction of the yaw axis direction (direction around the Z axis) and the pitch axis direction (direction around the Y axis).

  As described above, according to the present invention, in bonding and fixing of an optical component using an ultraviolet curable adhesive, the optical component is bonded and fixed on a substrate with high accuracy and easy position adjustment with respect to the laser light source. Can do.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 3 show a schematic configuration of a laser light source apparatus 10 according to an embodiment of the present invention. 1 is an overall perspective view of the laser light source device 10, FIG. 2 is a plan view thereof, and FIG. 3 is a side view thereof.

  The laser light source device 10 includes on a substrate 11 a semiconductor laser 12 as a laser light source, a lens unit 13 as an optical component, and a support 14 that holds the lens unit 13 by bonding. The laser light source device 10 constitutes a laser optical system in which the laser light emitted from the semiconductor laser 12 is collimated by the lens unit 13.

  Although the board | substrate 11 is comprised with metal substrates, such as aluminum, with high heat dissipation, for example, transparent substrates, such as not only this but glass, may be used.

  In the present embodiment, the semiconductor laser 12 is a laser element that oscillates blue laser light having a wavelength of 445 nm, and is fixed on the substrate 11 via a heat sink 15. The heat sink 15 is made of a metal block such as copper. The semiconductor laser 12 is bonded on the upper surface of the heat sink 15 with the optical axis 20 adjusted in the X direction in the drawing.

  The lens unit 13 has a function of converting a divergent light beam emitted from the semiconductor laser 12 into a parallel light beam and converting the optical axis 20 of the laser light emitted from the semiconductor laser 12 into a predetermined optical axis 21. The lens unit 13 includes a pair of collimator lenses 16 a and 16 b, a prism block 17 for converting the axial position, and a support plate 18 that supports the collimator lenses 16 a and 16 b and the prism block 17.

  The pair of collimator lenses 16a and 16b are arranged in parallel with each other so that the prism block 17 is sandwiched, and the axial positions are different from each other by a predetermined distance in the Y direction in the drawing. The optical axis of one collimator lens 16 a is aligned on the optical axis 20 of the semiconductor laser 12, and the other collimator lens 16 b emits the laser light whose axial position is converted by the prism block 17 along the optical axis 21. Let

  The support plate 18 is made of a rectangular plate having a rectangular cross section, and the collimator lenses 16a and 16b and the prism block 17 are bonded and fixed to one main surface thereof. The constituent material of the support plate 18 is not particularly limited, and can be composed of a metal substrate such as aluminum, or a transparent substrate such as glass or plastic.

  The support 14 is for bonding and fixing the lens unit 13 to the substrate 11 and is made of a transparent material such as glass or plastic that is transparent to ultraviolet rays. Particularly preferably, borosilicate crown glass (BK7) having good transmittance in the ultraviolet region is used. In the present embodiment, the support 14 has a hexagonal prism shape.

  The support 14 includes a first adhesive surface 14 a that is bonded to one side surface of a support plate 18 that is one component of the lens unit 13, and a second adhesive surface 14 b that is bonded to the substrate 11. The first and second bonding surfaces 14a and 14b are two surfaces orthogonal to each other, the first bonding surface 14a is formed on one side surface of the support 14 parallel to the XZ plane, and the second bonding surface 14b is parallel to the XY plane. The support 14 is formed on the bottom surface. The first adhesive surface 14a of the support 14 and the lens unit 13 and the second adhesive surface 14b of the support 14 and the substrate 11 are bonded and fixed by an ultraviolet curable adhesive 19, respectively. Yes.

  The first and second adhesive surfaces 14a and 14b of the support 14 are mirror-finished. Preferably, the surface roughness of the first and second bonding surfaces 14a and 14b is, for example, 3.2 S or less. Since the first and second adhesive surfaces 14a and 14b are mirror-finished, the application amount of the ultraviolet curable adhesive 19 can be reduced, and the thickness of the adhesive layer after curing can be reduced. In addition, it is preferable that each area | region of the support plate 18 side of the lens unit 13 adhere | attached with these adhesion surfaces 14a and 14b and the board | substrate 11 upper surface is also made into the same mirror finish.

  Further, by configuring the first and second bonding surfaces 14a and 14b with two surfaces (XY surface and XZ surface) orthogonal to each other, the position adjustment of the lens unit 13 can be adjusted in the X-axis direction, the Y-axis direction, the Z-axis direction, It is possible to carry out with respect to the five axis directions of the yaw axis direction (direction around the Z axis) and the pitch axis direction (direction around the Y axis).

  Next, a method for bonding and fixing the lens unit 13 in the laser light source device 10 configured as described above will be described. FIG. 4 is a process diagram illustrating a method for bonding and fixing the lens unit 13 to the substrate 11.

  First, as shown in FIG. 4A, a step of adjusting the optical axis position of the lens unit 13 with respect to the semiconductor laser 12 bonded to the substrate 11 via the heat sink 15 is performed.

  In this step, the position of the lens unit 13 is adjusted using the alignment clamp device 22. The alignment clamp device 22 has a mechanism for holding the lens unit 13 by vacuum-sucking a part of the upper surface periphery of the support plate 18. In addition, the alignment clamp apparatus 22 is not limited to said example, You may be comprised with the other clamp mechanism.

  The position of the lens unit 13 held by the alignment clamp device 22 is adjusted so that the optical axis of one collimator lens 16 a is aligned with the optical axis 20 of the semiconductor laser 12. The position adjustment of the lens unit 13 is performed via the alignment clamp device 22, and the lens unit 13 has a yaw axis direction around the Z axis and a pitch axis direction around the Y axis in addition to the X, X, and Z axis directions. After the position adjustment is performed in the total 5 axis directions (tilting direction), the state is maintained.

  Next, as shown in FIG. 4B, the support body 14 in which the ultraviolet curable adhesive 19 is applied to the first and second adhesive surfaces 14a and 14b is brought into contact with the side surface of the support plate 18 of the lens unit 13 and the upper surface of the substrate 11, respectively. Arrange.

  The adhesive surfaces 14 a and 14 b of the support 14 are in contact with the side surface of the support plate 18 of the lens unit 13 and the upper surface of the substrate 11 through the surface tension of the ultraviolet curable adhesive 19. The ultraviolet curable adhesive is a kind of a photocurable adhesive that is cured by being irradiated with ultraviolet rays, and exists in a liquid state having a certain degree of viscosity before the ultraviolet irradiation. Therefore, before the ultraviolet irradiation, the adhesive surfaces 14a and 14b of the support 14 are in a state of being adhered to the side surface of the support plate 18 and the upper surface of the substrate 11 with the surface tension of the ultraviolet curable adhesive. The support 14 moves on the substrate 11 due to the tension and is guided and arranged at an appropriate bonding position.

  In order to generate such a guiding arrangement phenomenon of the support 14, the ultraviolet curable adhesive 19 needs to have a low viscosity. Specifically, the viscosity of the ultraviolet curable adhesive 19 in an uncured state is preferably less than 1600 mPa · s. If this range is exceeded, the viscosity of the ultraviolet curable adhesive is too high, and it is difficult for the induced arrangement phenomenon of the support 14 utilizing the surface tension to occur.

  Further, in order to effectively generate the guiding arrangement phenomenon of the support 14, the surfaces of the bonding surfaces 14 a and 14 b of the support 14 are required to be smooth. In the present embodiment, as described above, these adhesive surfaces 14a and 14b, the side surface of the support plate 18 to which these surfaces are bonded, and the upper surface of the substrate 11 are mirror-finished. It is possible to efficiently perform the guide arrangement of the support body 14 using.

  Further, the UV curable adhesive 19 having a low viscosity is used, and the adhesive surfaces 14a and 14b of the support 14 are mirror-finished so that the application amount of the UV curable adhesive 19 can be reduced and bonded at the same time. The thickness of the layer can be reduced. Thereby, since the position shift of the lens unit 13 due to the curing shrinkage of the adhesive can be suppressed, it is possible to reduce the amount of change in the optical axis after the position-adjusted lens unit 13 is bonded and fixed.

  Subsequently, after placing the support 14 in contact, after confirming that there is no optical axis deviation in the lens unit 13, as shown in FIG. The ultraviolet curable adhesive 19 applied to the surfaces 14a and 14b is simultaneously cured. As a result, the lens unit 13 is bonded and fixed to the substrate 11 via the support 14. Note that after the lens unit 13 is bonded and fixed, the lens unit 13 is released from the bonding position holding action by the alignment clamp device 20.

  By simultaneously curing the ultraviolet curable adhesive 19 applied to the adhesive surfaces 14 a and 14 b of the support 14, curing shrinkage of the adhesive on each surface is caused by relative movement of the support 14 with respect to the lens unit 13 and the substrate 11. It is possible to absorb the optical axis shift of the lens unit 13 after the adhesive is cured.

  When the optical axis shift of the lens unit 13 is confirmed before the ultraviolet irradiation, the optical axis position of the lens unit 13 is readjusted via the alignment clamp device 22. In this case, since the lens unit 13 is supported on the substrate 11 via the two orthogonal surfaces 14a and 14b of the support 14, the position of the lens unit 13 can be adjusted in the five-axis direction described above.

  As described above, according to the present embodiment, after the optical axis of the lens unit 13 is adjusted with respect to the semiconductor laser 12, the support 14 in which the ultraviolet curable adhesive 19 is applied to the bonding surfaces 14a and 14b is used. Since the lens unit 13 is bonded and fixed on the substrate 11, the optical axis shift of the lens unit 13 due to curing shrinkage of the ultraviolet curable adhesive 19 can be effectively suppressed.

  In particular, by using a UV curable adhesive 19 having an uncured viscosity of less than 1600 mPa · s, it is possible to form a thin adhesive layer and minimize the effects of curing shrinkage. it can. Further, the surface tension of the ultraviolet adhesive 19 can be used to improve the sticking property between the support 14 and the lens unit 13 and the substrate 11, and at the same time, the support 14 can be guided and arranged at an appropriate bonding position. It becomes possible.

  Further, by sticking each bonding surface 14a, 14b of the support 14 to a mirror surface, the sticking property between the support 14, the lens unit 13 and the substrate 11 can be enhanced by utilizing the surface tension of the ultraviolet adhesive 19. At the same time, the support 14 can be guided and arranged to an appropriate bonding position. In addition, the adhesive layer can be formed thin, and the influence of curing shrinkage can be minimized.

  Furthermore, by performing the above-described lens unit bonding step with the semiconductor laser 12 turned on, monitoring of the change in the optical axis of the lens unit 13 from the adjustment of the optical axis of the lens unit 13 to the completion of bonding onto the substrate 11 is performed. can do. Thereby, it is possible to perform an adhesive fixing operation with very high accuracy.

  In this case, the optical axis position of the lens unit 13 is held by the alignment clamp device 22 even when the curing action of the ultraviolet curable adhesive 19 is started by the emitted light beam of the semiconductor laser 12, so that the optical axis change occurs. It can be avoided.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

The presence / absence of the induction arrangement phenomenon of the support 14 was examined using a plurality of types of ultraviolet curable adhesives having different viscosities in an uncured state. The experimental results are shown in FIG. Samples 1 to 4 used the following.
Sample 1: “UV15” manufactured by Master Bond
Viscosity 135mPa · s
Sample 2: “88075L5” manufactured by Kyoritsu Chemical Industry Co., Ltd.
Viscosity 350mPa · s
Sample 3: “TB3121” manufactured by ThreeBond
Viscosity 1100mPa · s
Sample 4: “UV-3000” manufactured by Daikin Industries, Ltd.
Viscosity 1600mPa · s

  As a result of the experiment, the induced arrangement phenomenon of the support 14 was observed in Samples 1 to 3, whereas the induction arrangement phenomenon of the support 14 was not observed in Sample 4. This is considered to be because when the viscosity of the sample 4 is 1600 mPa · s, the viscosity is too high and the induction arrangement phenomenon of the support 14 is difficult to occur. Accordingly, it is preferable to use an ultraviolet curable adhesive having an uncured viscosity of less than 1600 mPa · s, preferably 1100 mPa or less.

Moreover, it was confirmed that the adhesive layer which consists of the ultraviolet curable adhesive of Samples 1-3 can be formed thinner as a low viscosity adhesive. The amount of cure shrinkage of the adhesive is determined by the product of the cure shrinkage rate and the adhesive layer thickness. Therefore, when the maximum value of the change amount of the optical axis generated by the lens unit 13 being pulled toward the support 14 due to the curing shrinkage of the ultraviolet curable adhesive is estimated, 0.75 μm and 2. It becomes 88 micrometers and 3.36 micrometers (FIG. 5). However, in practice, since the support 14 is almost pulled toward the lens unit 13 side, the change in the optical axis of the lens unit 13 is less than half of the calculated value.
For reference, an example of an ultraviolet curable adhesive (sample 5) having an adhesive viscosity of 3000 mPa · s is shown in FIG. The maximum optical axis change amount in this case is 49 μm, and it can be seen that the samples 1 to 3 can bond and fix the lens unit 13 with much higher accuracy.

  As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to this, A various deformation | transformation is possible based on the technical idea of this invention.

  For example, in the above embodiment, the laser element that oscillates blue laser light having a wavelength of 445 nm has been described as an example of the semiconductor laser 12 that is a laser light source. However, the present invention is not limited to this, and the Nd-YAG laser source and the KTP or the like A wavelength that induces the start of curing of an ultraviolet curable adhesive, such as a SHG solid-state laser that generates green laser light having a wavelength of 532 nm and a laser element that oscillates blue-violet laser light having a wavelength of 405 nm. A laser light source of 550 nm or less may be used.

  In the above embodiment, the lens unit 13 having the above-described configuration is described as an example of the optical component. However, instead of this, a single lens element or an optical component other than the lens element, such as a mirror component, is used. The present invention is applicable to all optical components that require optical axis adjustment with respect to a laser light source, such as optical fibers and optical fibers.

  Furthermore, although the rectangular column-shaped transparent block body was used as the support body 14, the shape of the support body is not limited to this, and for example, a triangular prism-shaped support body 24 may be used as shown in FIG. Also in this case, it is preferable that the bonding surfaces 24a and 24b bonded to the lens unit 13 and the substrate 11 are constituted by two surfaces orthogonal to each other. Of course, these adhesion surfaces may not be two surfaces orthogonal to each other. For example, the inclined surface 24c of the support 24 may be an adhesion surface to the lens unit 13.

It is a perspective view which shows schematic structure of the laser light source apparatus by embodiment of this invention. It is a top view which shows schematic structure of the laser light source apparatus by embodiment of this invention. It is a side view which shows schematic structure of the laser light source apparatus by embodiment of this invention. It is a perspective view of each process explaining the adhesion fixing method of the optical component by embodiment of this invention. It is a figure which shows the experimental result explaining one Example of this invention. It is a perspective view which shows the modification of the structure of the laser light source apparatus by embodiment of this invention. It is principal part side sectional drawing which shows schematic structure of the conventional laser light source apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Laser light source device, 11 ... Board | substrate, 12 ... Semiconductor laser, 13 ... Lens unit, 14 ... Support body, 14a ... 1st adhesion surface, 14b ... 2nd adhesion surface, 15 ... Heat sink, 16a, 16b ... Collimator lens, DESCRIPTION OF SYMBOLS 17 ... Prism block, 18 ... Support plate, 19 ... Ultraviolet curable adhesive, 20, 21 ... Optical axis, 22 ... Alignment clamp apparatus

Claims (7)

In the method for bonding and fixing an optical component on the substrate on which the laser light source is installed, the optical component is bonded using an ultraviolet curable adhesive.
Adjusting the optical axis position of the optical component with respect to the laser light source;
A step of placing a transparent support in which an ultraviolet curable adhesive is applied to two different surfaces respectively bonded to the optical component and the substrate in contact with the optical component and the substrate;
And a step of irradiating the support with ultraviolet rays to simultaneously cure the ultraviolet curable adhesive applied to the two surfaces. The method for bonding and fixing an optical component according to claim 1, wherein the first and second bonding surfaces are two surfaces orthogonal to each other. The method for bonding and fixing an optical component according to claim 1, wherein the ultraviolet curable adhesive has an uncured viscosity of less than 1600 mPa · s. The method for bonding and fixing an optical component according to claim 1, wherein the steps are performed in a state where the laser light source is turned on. A laser light source;
A substrate on which the laser light source is installed;
In a laser light source device comprising the laser light source and an optical component installed on the substrate with the optical axis aligned,
A transparent support having a first adhesive surface bonded to the optical component and a second adhesive surface bonded to the substrate;
The optical component is bonded and fixed to the substrate via the support body in which an ultraviolet curable adhesive is applied to the first and second bonding surfaces. The laser light source device according to claim 5, wherein the first and second bonding surfaces are mirror-finished. The laser light source device according to claim 5, wherein a light source wavelength of the laser light source is 550 nm or less.

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