JP2003172856A - Method and device for assembling optical product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for assembling an optical product. <P>SOLUTION: While the gap quantity between an LD element 50 mounted on a 1st mount 52 and a wavelength converting element 54 mounted and fixed on a 2nd mount 56 is denoted as d0 and the gap quantity between the 1st mount 52 and 2nd mount 56 is denoted D1, they are united by applying an adhesive 62 to the gap between the 1st mount 52 and 2nd mount 56. Here, although the coupling efficiency is higher and higher as the gap quantity d0 between the LD element 50 and wavelength converting element 54 is smaller and smaller, and desirable, the yield possibly decreases since the gap quantity d0 decreases owing to shrinkage due to adhesive hardening and the LD element 50 and wavelength converting element 54 possibly abut against each other to break. For the purpose, the optical product which is high in yield and has high coupling efficiency can be assembled by setting the gap quantity d0 for a target gap quantity d1 so that d0=d1+αD1, where α is the volume shrinkage rate of the adhesive 62. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a light emitting element, which is a light source for generating a fundamental wave, and an optical wavelength conversion element having an optical waveguide into which the fundamental wave from the light emitting element is incident, which are coupled with high efficiency. More specifically, the present invention relates to an optical product assembling method and device, and more particularly, to an optical product assembling method and device for highly efficiently obtaining a second harmonic by mounting these elements on a mount and fixing the mounts with an adhesive. Regarding

[0002]

2. Description of the Related Art Conventionally, a laser beam generated from a fundamental wave light source is made incident on an optical wavelength conversion element made of a non-linear optical material to convert the wavelength into a second harmonic (shorter wavelength).
The technology to do is known.

When a light emitting element (semiconductor laser element, hereinafter referred to as LD element) is used as a fundamental wave light source, for example, as disclosed in the specification of Japanese Patent Application No. 11-93845 by the present applicant, It is widely practiced to bring the light emitting surface of the LD element and the light incident surface of the light wavelength conversion element into close proximity to each other to directly optically couple the two elements and to modularize the LD element and the light wavelength conversion element.

When the LD element and the light wavelength conversion element are directly coupled to each other to form an optical module as described above, a method of fixing both elements with an adhesive is often employed. The light emitting surface of the LD element and the light incident surface of the light wavelength conversion element may be directly fixed, or, as disclosed in the above specification, the LD element and the light wavelength conversion element may be provided in the first and second portions, respectively. It may be mounted on a mount and the mounts may be fixed to each other with an adhesive.

In the optical module in which the LD element and the light wavelength conversion element are bonded and fixed in this way, the positional relationship between the LD element and the light wavelength conversion element in the optical axis direction is the so-called submicron order, that is, 0.1 μm. There is a problem that the optical coupling efficiency is reduced even if the deviation is about 1 μm.

Therefore, when the two elements are combined, the both are aligned so that the laser beam as the fundamental wave emitted from the LD element is accurately incident on the end face (incident surface) of the optical waveguide of the optical wavelength conversion element. In addition to the step of fixing and fixing the both in that state, it is required to take measures so as not to cause the positional displacement of both elements due to subsequent transportation, storage environment, use environment, and temporal change.

In particular, since both elements are likely to be displaced due to thermal expansion of module constituent members due to changes in operating environment temperature, in the case of a type in which the mounts are joined to each other, the thermal expansion coefficient (linear expansion coefficient) of the mutual mounts is used. It is desirable to form the same material. However, when each mount is constructed by using materials having different linear expansion coefficients from other circumstances, stress acts between the thermally expanded mounts to move the bonding portion, and the LD element and the optical wavelength conversion element are moved. There will be a displacement between them.

Further, there is a possibility that the adhesive layer may be separated from the end face of the mount due to the stress concentration on the adhesive between the mounted mounts. The thinner the adhesive layer is, the greater the stress concentration due to the relative position variation of the mount becomes, and the adhesive layer is easily peeled off. To prevent this problem, it is preferable to form a thick adhesive layer,
If the adhesive layer is made too thick, thermal displacement or contraction of the adhesive layer due to temperature change may cause misalignment between mounts, that is, between the LD element and the light wavelength conversion element.

Due to the above circumstances, it is necessary to set the thickness of the adhesive layer to an appropriate value in consideration of the mount material, the storage temperature and the operating temperature of the optical module. The above-mentioned Japanese Patent Application No. 11-98845 discloses a simple method of adhering and fixing the mounts while maintaining a predetermined positional relationship. In this method, the gap between the LD element and the light wavelength conversion element and the adhesive layer The gaps between the mounts, which determine the thickness, are set equal. Therefore, if the gap between the LD element and the light wavelength conversion element is made small in order to secure high optical coupling efficiency between the LD element and the light wavelength conversion element, the gap between the mounts becomes small and the adhesive layer becomes thin, which may cause peeling. Occurs. That is, it was not possible to satisfy both the prevention of the positional deviation and the prevention of the peeling of the adhesive.

In view of this point, Japanese Patent Application No. 200 by the present applicant
According to the specification of 0-7317, a concave portion having a predetermined depth is provided on the end surface (bonding surface) of the mount to set the adhesive layer to a desired thickness regardless of the gap amount between the LD element and the light wavelength conversion element. A possible method is proposed.

According to this method, even if the distance between the LD element and the light wavelength conversion element is reduced to a state where there is almost no distance,
It is said that the thickness of the adhesive layer can be ensured by the depth of the above-mentioned recessed portion, and it is possible to satisfy both prevention of positional deviation and prevention of peeling of the adhesive.

[0012]

However, the above-described method of forming the recessed portion on the end surface of the mount requires extremely high-precision machining of the mount to be used. That is, a submicron-order polished surface is required in order to process the joint surface with a predetermined accuracy, and the component becomes expensive. If the squareness of the parts is not correct, L
The gap between the D element and the light wavelength conversion element is brought close to a state where there is almost no gap. As a result, the shrinkage of the adhesive may cause the elements to collide with each other and be damaged.
Further, in order to position the element with respect to the mount with sub-micron accuracy, very expensive and large-scale equipment is required, which poses a problem in terms of practicality.

On the other hand, a mount for fixing the LD element and the gap between the LD element and the light wavelength conversion element and a mount (hereinafter, referred to as a first mount) is formed by using an inexpensive member instead of using such an expensive polishing member having a groove. A method of independently setting the gap between the mount for fixing the light wavelength conversion element (hereinafter, referred to as the second mount) is also considered. Less than,
A specific example will be described.

The first method is as described in (1) to (3) below.

The LD element is pre-mounted on the first mount.

After the origin position is detected by moving the first mount and the second mount relative to each other by the moving mechanism to bring them into contact with each other, the distance (gap amount) between the joint surfaces of the first mount and the second mount is adjusted. Set to L1.

The light wavelength conversion element is placed on the second mount, and is pressed against the second mount with a constant load. As a result, the optical wavelength conversion element is restricted from moving in the vertical direction and is movable in the optical axis direction. In this state, after adjusting the attitude of the free light wavelength conversion element to make the end faces of the LD element and the light wavelength conversion element parallel,
The first mount and the second mount are brought close to each other by a distance L1-A + B. At this time, the LD element and the light wavelength conversion element are brought into contact with each other, and the light wavelength conversion element movable with respect to the second mount slides on the second mount. As a result, the gap amount between the LD element and the light wavelength conversion element is zero, and the gap amount between the first mount and the second mount is L1- (L1-A + B) =
It is set to AB.

Subsequently, the gap amount between the LD element and the light wavelength conversion element is set to B by moving the second mount away from the first mount by a distance B, and the gap amount between the first mount and the second mount is ( AB- + B = A is set. In this way, gaps (gap amounts B and A) are individually set between the LD element and the light wavelength conversion element and between the first mount and the second mount.

As another method (second method), the following methods (1) to (4) have been proposed.

The LD element is mounted on the first mount in advance. The light wavelength conversion element and the second mount are not adhered to each other, and the light wavelength conversion element is independently held on the second mount and is in a movable state.

After the origin position is detected by moving the first mount and the second mount relative to each other by the moving mechanism to bring them into contact with each other, the gap amount between the joint surfaces of the first mount and the second mount is set to A. To do.

After adjusting the attitude of the free light wavelength conversion element to make the end faces of the LD element and the light wavelength conversion element parallel,
The light wavelength conversion element is moved to set the gap amount to the LD element to B.

By placing the light wavelength conversion element on the second mount by the light wavelength conversion element holding means, a gap (gap amount B, A between the LD element and the light wavelength conversion element and between the first mount and the second mount). ) Is set individually.

When the first method is adopted, there are the following inconveniences. That is, an automatic stage driven by a stepping motor is usually used as a mechanism for relatively moving the first mount and the second mount. However, this motorized stage usually has a certain range of backlash, and during reciprocating movement, it is not possible to guarantee that it will move by a set amount due to this effect. Therefore, in the step of setting the gap by moving the light wavelength conversion element in the opposite direction after abutting the light wavelength conversion element on the LD element, the gap setting amount varies due to the influence of the backlash.

Further, the sliding friction of the optical wavelength conversion element with respect to the second mount changes depending on the magnitude of the load pressing the optical wavelength conversion element mounted on the second mount against the second mount. Therefore, if the load is too large, when the optical wavelength conversion element is abutted against the LD element, the optical wavelength conversion element does not immediately slide on the second mount due to the action of static friction force, and the LD element is bent. As a result, the contact position between the LD element and the light wavelength conversion element changes. As a result, when the second mount (light wavelength conversion element) is returned in the opposite direction for setting the gap, the amount of gap between the LD element and the light wavelength conversion element is reduced until the abutting stress is released and the bending amount returns. There was a risk that the value would remain zero and the gap amount would be set smaller than the target value (the gap amount would vary).

On the other hand, if the load is not increased to some extent, there is a disadvantage that the thickness of the adhesive cannot be made constant when the optical wavelength conversion element and the second mount are bonded.

The second method also has the following disadvantages. That is, the light wavelength conversion element is usually held by a clamp or vacuum suction. At this time, the light wavelength conversion element is held so that the reference surface of the device and the mount contact surface of the light wavelength conversion element are always parallel. However, the optical wavelength conversion element mounting surface of the second mount is mounted on the device,
Due to variations in parallelism and variations in surface roughness, it cannot always be parallel to the mount contact surface of the optical wavelength conversion element. If the parallelism between the mount contact surface of the light wavelength conversion element and the light wavelength conversion element mounting surface of the second mount is not ensured, the light wavelength conversion element (mount contact surface) is replaced with the second mount (light wavelength conversion element). In the step of mounting on the (mounting surface), there is a problem that the set gap and angle are displaced, and as a result, the gap amount varies.

In order to ensure the parallelism between the mount contact surface of the light wavelength conversion element and the light wavelength conversion element mounting surface of the second mount, a holding mechanism for the light wavelength conversion element may be provided with a surface matching mechanism. Though conceivable, there are drawbacks that the device is large and expensive, and the cycle time is long.

By the way, the gap amount between the LD element and the light wavelength conversion element is a very important parameter in the coupling efficiency of the optical coupling, and the smaller the gap, the more the coupling efficiency can be improved. However, if the LD element and the light wavelength conversion element come into contact with each other, it may cause a positional shift, which may lead to a large decrease in coupling efficiency.

Therefore, it is desired to assemble the optical module in a state in which the variation in the gap amount between the LD element and the light wavelength conversion element is small and the distances are as close as possible. However, due to the various factors described above, the finished gap amount of the LD element and the optical wavelength conversion element varies greatly. Therefore, in order to prevent the LD element and the optical wavelength conversion element from coming into contact with each other, the initial setting value should be increased in consideration of the yield. There was no choice but to enter a vicious circle in which the coupling efficiency did not increase.

That is, the variation in the gap amount between the LD element and the light wavelength conversion element at the time of setting hinders the reduction of the final gap amount between the LD element and the light wavelength conversion element without bringing the LD element and the light wavelength conversion element into contact with each other. It was.

On the other hand, the final gap amount when the gap is set by the above two methods also has the following problems.

That is, the LD due to the shrinkage accompanying the curing of the adhesive
The final (finished) gap amount is smaller than the set gap amount B between the element and the light wavelength conversion element. Therefore,
Depending on the amount of shrinkage, the LD element and the light wavelength conversion element may collide with each other during assembly, resulting in a large reduction in yield. That is, even if the gap amount can be set well, the above problem will occur unless the variation of the gap amount as the finished dimension falls within the predetermined range.

In consideration of the above facts, an object of the present invention is to provide an optical product assembling method and an assembling apparatus for producing an optical product optically coupled with high efficiency at a high yield.

[0035]

The invention according to claim 1 is
By joining the first holding member to which the first optical element is fixed and the second holding member to which the second optical element on which the emitted light of the first optical element is incident are fixed, the first optical element and the second optical element In the method of assembling an optical product that optically couples optical elements,
The distance between the end surface of the first holding member to which the first optical element is fixed and the end surface of the second holding member that is arranged parallel to the end surface of the first holding member and to which the second optical element is fixed is D1. At the same time, a first step in which the distance between the end surface of the first optical element and the end surface of the second optical element which are parallel to each other is set to d0,
A second step of joining the first holding member and the second holding member by applying an adhesive between the end surface of the first holding member and the end surface of the second holding member; When the contraction rate is α, the interval d0 is set so as to satisfy the relationship of d0> αD1.

The operation of the invention according to claim 1 will be described.

When assembling the optical product, first, the end surface of the first holding member and the second end surface parallel to the end surface of the first holding member.
The distance between the end surface of the holding member is D1 and the distance between the end surface of the first optical element on the first holding member and the end surface of the second optical element on the second holding member is d0.

Next, an adhesive is applied between the end faces of the first holding member and the second holding member to join the first holding member and the second holding member to assemble the optical product. here,
Assuming that the shrinkage rate of the adhesive applied between the first holding member and the second holding member is α, by setting d0 larger than αD1, the adhesive shrinks after the assembly, and the first optical element and the second optical element. There is an increased possibility that it is possible to prevent the optical coupling efficiency from being deteriorated due to damage of the optical element or change in the relative positional relationship between the end faces of the element.

When the final target distance between the end surface of the first optical element and the end surface of the second optical element is d1, the distance d0 may satisfy the relationship of d0 = d1 + αD. Is preferably set.

In this case, the end face of the first optical element and the second optical element
The distance d0 set between the end faces of the optical element is d0 = d1 +
The final target value d1 of the distance between the end faces of the first optical element and the second optical element is set because the setting is made to satisfy the relationship of αD1, that is, the setting is made in consideration of the shrinkage amount due to the curing of the adhesive. Can be suppressed to a minimum.

According to a second aspect of the invention, the first holding member to which the first optical element is fixed and the second holding member to which the second optical element on which the light emitted from the first optical element is incident are fixed are joined. In the method for assembling an optical product in which the first optical element and the second optical element are optically coupled to each other, the end surface of the first holding member to which the first optical element is fixed is parallel to the end surface of the first holding member. And the distance between the end surface of the second holding member to which the two optical elements are fixed is D1, and the distance between the end surfaces of the first optical element and the second optical element, which are parallel to each other, is d0. And a second step of joining the first holding member and the second holding member by applying an adhesive between the end surface of the first holding member and the end surface of the second holding member. 5 μm <D1 <30 μm It is characterized by setting D1.

The operation of the invention according to claim 2 will be described.

If the distance D1 between the end faces of the first holding member and the second holding member is set to 30 μm or more, the fluctuation of the distance due to the contraction of the adhesive becomes too large, and the first optical element and the second optical element after the contraction of the adhesive are too large. The variation in the distance between the end faces of the element becomes large. On the other hand, if the distance D1 is set to 5 μm or less, the adhesive layer becomes too thin, and the first temperature may fluctuate due to a change in environmental temperature due to a difference in linear expansion coefficient between the first holding member and the second holding member.
The adhesive layer may peel off due to the stress acting between the holding member and the second holding member. Therefore, the distance D1 between the end faces of the first holding member and the second holding member is set to 5 μm <D1 <3.
By setting the thickness to 0 μm, it is possible to suppress variations in the final spacing d1 between the end faces of the first optical element and the second optical element, and to prevent the adhesive layer used for joining the first holding member and the second holding member from each other. Peeling can be suppressed.

According to a third aspect of the present invention, there is provided a first holding member to which the first optical element is fixed and a second holding member to which the second optical element on which the light emitted from the first optical element is incident are fixed. In the method of assembling an optical product in which a first optical element and a second optical element are optically coupled by joining, an end surface of the first holding member to which the first optical element is fixed is parallel to an end surface of the first holding member. After setting the distance from the end surface of the second holding member to D0, the second optical element is placed on the second holding member and the end surface of the second optical element is set to the end surface of the first optical element. A first step of parallelizing, a second step of interposing an adhesive between the second optical element mounted on the second holding member and the second holding member, and the second holding member being the first The second optical element is moved to the holding member side by a distance D0−D1 + d0, and the second optical element is moved to the first member. A third step of bringing the second optical element into contact with the first optical element after stopping the movement of the second holding member, and curing the adhesive in the state where the second optical element is brought into contact with the first optical element. Between the fourth step of joining the two holding members, the fifth step of moving the second holding member by the distance d0 in the direction of separating from the first holding member, and between the end surfaces of the first holding member and the second holding member. And a sixth step of applying an adhesive to the first holding member and joining the second holding member.

The operation of the invention according to claim 3 will be described.

First, after the distance between the second holding member and the first holding member is set to D0, the second holding member is moved to the distance D0-D1 + d.
The second optical element is brought into contact with the first optical element by approaching the first holding member by 0, and after the contact, the second optical element is slid on the second holding member. Further, the second holding member is separated from the first holding member by the distance d0. In this way, the first
It is possible to accurately form a gap having a distance d0 between the optical element and the second optical element and a distance D1 between the first holding member and the second holding member. By applying an adhesive to the gap between the first holding member and the second holding member, the first holding member and the second holding member are joined to assemble the optical product with high accuracy.

Here, the second holding member placed on the second holding member.
Before the optical element is brought into contact with the first optical element, an adhesive is applied between the second optical element and the second holding member to reduce the sliding resistance. When it comes into contact with the element, it immediately slides on the second holding member.
Therefore, when the second optical element comes into contact with the first optical element, the first optical element is prevented from being bent, and the gap is accurately adjusted to the predetermined distance d0 by the step of separating from the first optical element. Can be formed.

According to a fourth aspect of the present invention, there is provided a first holding member to which the first optical element is fixed and a second holding member to which the second optical element on which the light emitted from the first optical element is incident are fixed. In an optical product assembling apparatus for optically coupling a first optical element and a second optical element by joining, a first fixing means for fixing a first holding member to which the first optical element is fixed, and the second optical element. Second fixing means for fixing the second holding member to which is fixed, and the second fixing means fixed to the second fixing means.
Adjusting means for positioning and adjusting the holding member with respect to the first holding member, and the second holding member for the first holding member by the adjusting means.
By bringing the second optical element mounted on the second holding member into contact with the first optical element by bringing the holding member closer to the predetermined distance, the second optical element relatively moves on the second holding member. A pressing unit that movably presses the second optical element against the second holding member, and a bending prevention unit that prevents the first optical element from bending when abutting the second optical element. To do.

The operation of the invention according to claim 4 will be described.

By using such a device, the first optical element and the second optical element are positioned at a predetermined interval (hereinafter sometimes referred to as a gap), and the gap between the first holding member and the second holding member is set. In order to form it with high accuracy, the procedure is as follows.

First, the first holding member to which the first optical element is fixed is fixed to the fixing means. Next, by fixing the second holding member to the adjusting means and performing positioning adjustment by the adjusting means, a gap can be accurately formed between the second holding member and the first holding member. For example, the second holding member is brought into contact with the first holding member to detect the origin position, and the second holding member is separated from the first holding member by a predetermined distance based on the origin position. The gap can be accurately formed between the holding member and the second holding member.

Next, the second optical element is placed on the second holding member and pressed by the pressing means against the second holding member. In this state, in order to detect the origin position of the second optical element with respect to the first optical element, the adjusting means is driven to bring the second holding member close to the first holding member. As a result, the second optical element mounted on the second holding member comes into contact with the first optical element fixed on the first holding member. After the contact, even if the second holding member further approaches the first holding member, the second member is pressed by the second member.
Since the second optical element pressed against the holding member slides on the second holding member, there is no possibility that an excessive force acts between the optical elements to damage the optical element. Further, even if the second optical element comes into contact with the first optical element, the first optical element is prevented from being bent by the bending prevention means.

Furthermore, since the second optical element is bonded to the second holding member by applying the adhesive while the second optical element is pressed against the second holding member by the pressing means, it is necessary to solidify the adhesive. The shrinkage prevents the posture of the second optical element on the second holding member from changing.

After that, by separating the second holding member from the first holding member, the first holding member and the second holding member, the first optical element and the second optical element can be accurately arranged, A predetermined gap can be formed.

Since the second optical element is pressed against the second holding member by the pressing means, there is no possibility that the posture (optical axis direction, etc.) will change even if it comes into contact with the first optical element.

In this state, the adhesive is applied to the accurately formed gap between the first holding member and the second holding member, so that the first holding member and the second holding member are exposed to light as the adhesive hardens. The displacement in the direction perpendicular to the axis is prevented. As a result, the first optical element and the second optical element can be positioned and fixed while being separated by a predetermined distance and can be optically coupled with high efficiency.

It is preferable that the deflection preventing means is, for example, a supporting means that supports the back surface of the end surface of the first optical element that is in contact with the second optical element.

In this case, the supporting means supports the back surface of the first optical element to reliably suppress the bending of the first optical element when the second optical element abuts against the first optical element. You can Therefore, the gap can be accurately formed between the first optical element and the second optical element.

[0059]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical product assembling apparatus according to an embodiment of the present invention will be described with reference to FIGS.

First, the optical product assembling apparatus will be described.
The assembling method will be described in detail.

As shown in FIG. 1, the optical product assembling apparatus 10 includes a first mount 5 to which an LD element 50 described later is fixed.
2, the fixed stage 12 on which the 2 is mounted, the adjustment stage 14 on which the second mount 56 to which the wavelength conversion element 54 described later is fixed is mounted, the output detection unit 16 used in the alignment process described below, and the below described Basically, the pressing member 18, the ultraviolet irradiation member 20 that irradiates ultraviolet rays at the time of joining, and the CCD camera 22 for confirming the positioning state.

The fixed stage 12 has a first side surface on the upper side surface.
The holding member 24 is provided to fix the fixed stage 52 on the stage by holding the side surface of the mount 52. In the vicinity of the fixed stage 12, a power supply device (not shown) that energizes the LD element 50 in the aligning step described later is provided. Further, on the fixed stage 12, a support member 25 that supports the back surface of the LD element 50 and prevents the LD element 50 from bending when the wavelength conversion element 54 abuts is disposed.

The adjusting stage 28 is mounted on the base 26 so that the adjusting table 28 can be precisely displaced, and the adjusting table 28 is sandwiched by the side surface of the second mount 56 to which the wavelength conversion element 54 is fixed. The holding member 30 fixed on the top is provided.

The adjusting table 28 is constructed so that it can be adjusted on three axes by a mechanism (not shown) on the base table 26. That is,
In FIG. 1, an X axis perpendicular to the paper surface, a Y axis that is a vertical direction in FIG. 1, a Z axis that is a direction toward and away from the fixed stage 12, and around the X axis (θx) and around the Y axis (θy). It is equipped with a mechanism that can be adjusted accurately.

The output detector 16 also detects the output of the collimator lens 34, which collimates the light emitted from the wavelength conversion element 54 onto the stage 32, and the output of the collimated light emitted from the collimator lens 34. Meter 3
6 is provided. The output of the power meter 36 is input to a control unit (not shown), and the adjustment stage 14 is drive-controlled so that the output value becomes maximum.

The pressing member 18 is provided on the adjusting table 28, and is configured so that the tip portion 18A can be moved in the Y-axis direction and the Z-axis direction, and the wavelength conversion element 54 is set in the gap adjustment described later. It is pressed against the second mount 56. A rotatable ball 40 is arranged at the tip portion 18A of the pressing member 18, and elastically presses the wavelength conversion element 54 by the elastic force of the coil spring 42.

Next, the first mount 52 mounted on the fixed stage 12 and the adjustment stage 14 (adjustment table 28).
The LD element 50, the second mount 56, and the wavelength conversion element 54 will be described with reference to FIG.

The first mount 52 has a convex shape, and the LD element 50 is mounted (fixed) on the top surface of the convex portion. On the other hand, the second mount 56 has a substantially rectangular shape and mounts and fixes the wavelength conversion element 54 on the upper surface thereof.
The convex portion 56 for joining is formed on the side surface joined to the first mount 52.
A is formed. The wavelength conversion element 54 also has a substantially rectangular shape, and a planar waveguide is formed along the longitudinal direction thereof.

The optical product assembling apparatus 1 thus configured
LD element 5 fixed on the first mount 52 using 0
0 and the wavelength conversion element 54 fixed on the second mount 56.
The manufacturing process for accurately positioning is described in detail. For convenience of description, the description of the stage is omitted.

First, the first mount 52 to which the LD element 50 is fixed is pressed against a stepped portion (not shown) on the fixed stage 12, and is sandwiched by the sandwiching member 24 to be positioned at a predetermined position on the fixed stage 12 (see FIG. 3 (A)). The LD element 50 is fixed to the projection of the first mount 52 at a position farthest from the adjustment stage 14 in the Z-axis direction, and the light emitting surface thereof is located at the adjustment stage 14.
Looking to the side.

Next, the second mount 52 is attached to the adjustment stage 1
4 is pressed against a stepped portion (not shown) on the upper surface of FIG.
(See (A)). In addition, a protrusion 56A for bonding, which will be described later, is arranged at the tip end of the second mount 56 on the Z-axis direction fixed stage side.

Subsequently, the adjustment stage 14 is driven to drive the second stage.
By rotating the mount 56 in the θx direction and the θy direction, the end surface of the first mount 52 and the convex portion 56A of the second mount 56 are rotated.
After making the front end surfaces of the first mount 52 parallel to each other (hereinafter, sometimes referred to as surface matching), the end surface of the first mount 52 and the front end surface of the convex portion 56A of the second mount 56 are brought into contact with each other so that the second mount with respect to the first mount 52 The origin position of 56 is detected (see FIG. 3B).

Specifically, while the operator observes the image from the CCD camera 22 on a monitor (not shown), the adjustment stage 14 is driven to drive the convex portion 56 of the second mount 56.
Adjustment base 28 until A contacts the end surface of the first mount 52.
Is moved to the fixed stage side (hereinafter, referred to as Z1 direction) in the Z-axis direction. When the convex portions 56A of the first mount 52 and the second mount 56 contact each other, the adjustment stage 2
The drive of No. 8 is stopped, and the Z-axis direction position of the adjusting table 28 is stored in the control unit (not shown) as the origin position of the second mount 56 with respect to the first mount 52. By moving the second mount 56 with this origin position as a reference,
The gap (gap) between the first mount 54 and the second mount 56 is accurately formed.

Subsequently, the adjustment stage 14 is driven to move the adjustment table 28 (second mount 56) by 50 μm in the direction (hereinafter, referred to as Z2 direction) away from the fixed stage 12 in the Z-axis direction, and the first mount 52 is moved. A gap of 50 μm is accurately formed between the second mount 56 and the second mount 56. In this embodiment, the gap amount is set to 50 μm, but it may be set to any value in consideration of operability.

In this state, the wavelength conversion element 54 is placed on the second mount 56 (see FIG. 3D1).

Next, the tip of the pressing member 18 is lowered onto the wavelength conversion element 54, and the ball 40 at the tip is pressed against the wavelength conversion element 54 by the elastic force of the coil spring 42 (see FIG. 4E). As a result, the wavelength conversion element 54 causes the second mount 56 to move due to the elastic force of the coil spring 42.
Can be pressed against. In this state, an external force is applied to the wavelength conversion element 54 based on the image of the CCD camera 22 (for example, the operator presses with a pin) to generate a second image.
Move the wavelength conversion element 54 in the X direction on the mount to move to L
The optical axes of the D element 50 and the wavelength conversion element 54 are matched. Further, the wavelength conversion element 54 is rotated in the θy direction so as to be face-aligned with the LD element 50. That is, the light emitting surface (emission surface) of the LD element 50 and the end surface (incident surface) of the wavelength conversion element 54 are made parallel. At this time, since the pressing member 18 is in contact with the wavelength conversion element 54 via the rotatable ball 40, the wavelength conversion element 54 can rotate in the θy direction.

At this time, the wavelength conversion element 54 will be described later in 34.
It is closer to the LD element 50 than μm.

Further, an ultraviolet curable adhesive 60 is dropped on the side surface of the wavelength conversion element 54 on the second mount 56 (see FIGS. 4F and 7F). As a result, the adhesive 60 penetrates between the wavelength conversion element 54 and the second mount 56.

After that, the adjustment stage 14 is driven to move the second mount 56 (wavelength conversion element 54) in the Z1 direction.
It is moved by .mu.m until the gap between the end surface of the first mount 52 and the tip surface of the convex portion 56A of the second mount 56 becomes 16 .mu.m (see FIGS. 5 (H) and 7 (H)). At this time, the wavelength conversion element 54 comes into contact with the LD element 50 before the second mount 56 and the first mount 52 have a predetermined space (16 μm) (see FIGS. 4G and 7G). After that, the wavelength conversion element 54 relatively slides on the second mount 56 as the second mount 56 moves in the Z1 direction. At this time, since the wavelength conversion element 54 is pressed against the second mount 56 via the ball 40 by the elastic force of the coil spring 42 provided at the tip of the pressing member 18, the wavelength conversion element 54 remains in a fixed posture. The end surface of the wavelength conversion element 54 and the light emitting surface of the LD element 50 remain parallel to each other and slide on the second mount 56.

In particular, the wavelength conversion element 54 and the second mount 5
Since the adhesive 60 permeates between 6 and the sliding resistance of the wavelength conversion element 54 is reduced, the wavelength conversion element 54 smoothly slides on the second mount 56 immediately after contacting the LD element 50. Thus, it is possible to reliably prevent the LD element 50 from being bent by being applied with an excessive pressing force and from being damaged.

Further, since the supporting member 25 that abuts and supports the back surface of the LD element 50 is provided on the fixed stage 12, the LD element 50 is further prevented from being bent by the abutting of the wavelength conversion element 54. It can be prevented satisfactorily.

Then, the ultraviolet irradiation member 20 is lowered,
Ultraviolet rays are radiated to the adhesive application portion (see FIG. 5 (I)). At this time, the posture of the wavelength conversion element 54 on the second mount may change due to contraction accompanying the curing of the adhesive agent 60.
Since it is pressed against the mount 56, the posture change can be prevented. Further, since the wavelength conversion element 54 is brought into contact with the LD element 50, the wavelength conversion element 54 may be displaced when the adhesive 60 is cured only in the direction away from the LD element 50. The possibility that the distance between the conversion element 54 and the LD element 50 varies will be reduced.

However, if the adhesive curing step is completed in this state, the ultraviolet rays will not be irradiated to the lower part of the pressing member 18 (ball 40), so the pressing member 1 will start halfway.
By separating 8 from the wavelength converting element 54 and retracting in the Z2 direction (FIG. 5 (I), two-dot chain line position → solid line position), ultraviolet rays are evenly applied to the adhesive application position.

If the ball 40 is formed smaller than the width of the wavelength conversion element 54, the adhesive 60 can be efficiently cured by irradiating ultraviolet rays from the vertical direction.

Subsequently, the adjusting stage 14 is driven to move the adjusting table 28 (second mount 56) by 4 μm in the Z2 direction (see FIGS. 5 (J) and 8 (J)). The adjustment stage 14 is provided with a linear sensor that can accurately detect the amount of movement of the second mount 56 in the Z direction, and by controlling the drive of the adjustment stage 14 based on the detected value, the adjustment stage 14 can be moved accurately. . This is to prevent an error from occurring due to backlash when moving in the opposite direction when a stepping motor or the like is used. As a method of avoiding the influence of backlash in the adjustment stage 14, once the second mount 56 is set to 4 μm or more in the Z2 direction, for example, 10 μm.
It is also possible to consider a method in which, after the movement, the movement is made again 6 μm in the Z1 direction.

In this way, the second mount 56 can be moved accurately
By moving μm in the Z2 direction, the LD element 50
The gap between the light-emitting surface of the and the end surface of the wavelength conversion element 54 is 4 μm
Therefore, the gap between the end surface of the first mount 52 and the tip surface of the convex portion 56A of the second mount 56 is 20 μm.

Here, the LD element 50 and the wavelength conversion element 54
The final target value of the gap between and is 2 μm, but the actual target value is 4 μm. The difference between the final target value and the set value of the gap is due to the contraction of the adhesive 62. That is, as shown in FIGS. 10A and 10B, even when the distance between the LD element 50 and the wavelength conversion element 54 is set to d0, the first mount 52 and the second mount 5
This is because it is considered that the interval d0 set by the contraction of the adhesive 62 applied to the gap of 6 changes to d1.
Here, when the volume shrinkage rate of the adhesive 62 is α, the maximum shrinkage amount of the adhesive 62 in the Z direction is considered to be αD1. Therefore, when the volume contraction rate (α) of the adhesive 62 is 10%, the gap (D1) set between the first mount 52 and the second mount 56 is 20 μm, and therefore 2 μm.
(20 μm × 0.1) is considered to be the maximum shrinkage amount of the gap (D1). Therefore, 4 μm (2 μm (d0) +2 μm
This is because if (d1) is secured, a gap can be accurately formed in the vicinity of 2 μm even if the adhesive 62 contracts.

In this state, L
The D element light emitting element 50 is caused to emit light, and the adjustment stage 14 is driven to move the second mount 56 (wavelength conversion element 54) in the X axis direction and the Y axis direction. At this time, the wavelength conversion element 54
Light emitted from the laser beam enters the power meter 36 through the collimator lens 34, and the output value thereof is detected. This output value is input to a control unit (not shown), and the adjustment stage 14
Is feedback-controlled, so that the second mount 56 (wavelength conversion element 54) is positioned at a position where the output value is maximized (see FIGS. 6K and 8K).

Next, an anaerobic ultraviolet curing adhesive 62 is applied between the end surface of the first mount 52 and the tip surface of the convex portion 56A of the second mount 56 (FIG. 6 (L), FIG. 8
(See (L)). Further, the pair of ultraviolet irradiation members 20 are brought close to each other from above and below, and ultraviolet rays are irradiated to the adhesive application portion, whereby the adhesive can be rapidly cured (FIG. 6).
(See (M)). Therefore, the LD element light emitting element 50 and the wavelength conversion element 54 can be arranged at a predetermined distance (4 μm) from the wavelength conversion element 54 so as to have a high output. By using the anaerobic adhesive 62, it is possible to completely cure even if the ultraviolet ray irradiation amount is insufficient.
It is possible to prevent the relative positional relationship between the mount 52 and the second mount 56 from changing.

By joining the first mount 52 and the second mount 56 in this way, an integrated optical module including the LD element 50 and the wavelength conversion element 54 is formed.
The adhesives 60 and 62 can be completely cured by leaving them in an aging oven at 0 ° C. for 12 hours. Although the aging condition is 90 ° C. for 12 hours here, the aging condition can be appropriately changed based on the curing performance of the adhesive and the temperature resistance of the element. It is also conceivable to pass the optical module through a UV oven as a method for promoting the curing of the adhesive.

The optical module is assembled as described above.

By the way, in the assembly process, the final target gap amount between the LD element 50 and the wavelength conversion element 54 is set to 2
The reason why μm is set is that when the optical module is assembled by this assembling method and the final gap amount between the LD element 50 and the wavelength conversion element 54 is measured, a probability distribution as shown in FIG. 11 is obtained, and almost all the optical modules are assembled. This is because it has been confirmed that it is possible to prevent the LD element 50 and the wavelength conversion element 54 from coming into contact with each other due to the subsequent contraction of the adhesive 62 and exerting stress. In addition, 4μ which is the maximum within the range of 3σ
This is because it was confirmed that the coupling efficiency in the optical module was 70% or more even with a gap amount of m, and that an optical module having a sufficiently high coupling efficiency could be manufactured with a high yield.

Also, the first mount 52 and the second mount 5
20 μm of the set interval D1 of 6 is 5 μ <D1 <3
Other values may be used as long as they are in the range of 0 μm. This is because, if the distance D1 is set to 30 μm or more, the fluctuation of the distance D1 due to the contraction of the adhesive 62 becomes too large, and the dispersion of the distance between the LD element 50 and the wavelength conversion element 54 after the contraction of the adhesive becomes large. . On the other hand, if the distance D1 is 5 μm or less, the layer of the adhesive 62 becomes too thin, and the first mount 5
This is because the adhesive layer may be peeled off by the stress acting between the first mount 52 and the second mount 56 due to the change in the environmental temperature based on the difference in the linear expansion coefficient between the second mount 56 and the second mount 56. That is, the first mount 52
And the distance D1 between the second mount 56 and 5 μm <D1 <30
By setting the thickness to μm, it is possible to suppress the variation in the final distance between the LD element 50 and the wavelength conversion element 54, and to suppress the peeling of the adhesive 62.

As described above, in the optical module assembling method using the optical product assembling apparatus 10 according to this embodiment,
The mount 52 and the second mount 56 are the LD element 50.
The wavelength conversion element 54 and the wavelength conversion element 54 can contact each other independently, and the origin position can be detected. Therefore, it is possible to accurately form the gap between the mounts and between the elements.

Further, since the wavelength conversion element 54 is pressed against the second mount 56 by the pressing member 18, the adjustment table 28
There is no possibility that the attitude (optical axis direction, etc.) of the wavelength conversion element 54 will change due to movement of the (second mount 54).

Moreover, the wavelength conversion element 54 is mounted on the second mount 56 and is pressed by the pressing member 18 (coil spring 42).
The second mount 56 through the ball 40 by the elastic force of
Since it is simply pressed by the external force, the wavelength conversion element 54 can slide on the second mount 56 only by an external force.

Further, the LD element 50 and the wavelength conversion element 54
The final gap amount (d1) between the LD element 50 and the wavelength conversion element 54 is set by setting the set gap amount (d0) between the LD element 50 and the wavelength conversion element 54 to a value (4 μm) in consideration of the shrinkage amount accompanying the curing of the adhesive 62. Can be brought close to the target value (2 μm). That is, it is possible to suppress variations in the final gap amount.

In particular, the second mount 56 and the wavelength conversion element 5
After the adhesive 60 is interposed between the wavelength conversion element 5 and
4 is brought into contact with the LD element 50, the wavelength conversion element 54
The sliding resistance with respect to the second mount 56 is reduced, and the amount of bending of the LD element 50 due to contact is suppressed. Further, since the back surface of the LD element 50 is supported by the supporting member 25, the bending of the LD element 50 due to the contact of the wavelength conversion element 54 is further reduced, and the LD element 50 and the wavelength conversion element 54
The setting gap amount of can be set with higher accuracy.

Since the target value of the final gap amount is set to 2 μm, as shown in the graph of FIG. 11, even if the gap setting amount, the product accuracy, and the variation in the adhesive shrinkage affect the LD element 50 after assembly. Can be reliably prevented from hitting the wavelength conversion element 54 and being damaged. In addition, since the gap amount within the range of 3σ is 4 μm at the maximum, the coupling efficiency between the LD element 50 and the wavelength conversion element 54 is 70% or more (see FIG. 12), and a highly efficient optical module can be manufactured with a high yield. become. The target value of the gap amount between the LD element 50 and the wavelength conversion element 54 is not limited to 2 μm, but the LD element 50 and the wavelength conversion element 54 are not limited thereto.
If they are assembled in a state where they are in contact with each other and a stress is applied, a positional shift occurs, which leads to a decrease in coupling efficiency and a reduction in yield, and therefore it is preferable to avoid.

Further, even when the wavelength conversion element 54 is bonded to the second mount 56, the pressing member 18 presses it. Therefore, it is possible that the posture of the wavelength conversion element 54 changes due to contraction due to curing of the adhesive. Optical products that can be prevented and have high coupling efficiency can be formed.

The first mount 52 and the second mount 56 are the fixed stage 12 and the adjustment stage 1 respectively.
Since it is fixed to the No. 4 (adjustment table 28), it is possible to accurately form a gap by detecting the origin after the surface alignment, and it is possible to precisely integrate the gap by applying the adhesive 62 to the gap. .

In this embodiment, the first mount 52
However, the shape is not limited to this. For example, as shown in FIG. 9 (A), it may be a substantially columnar mount 52 having a flat side surface, or as shown in FIG. 9 (C), a rectangular mount 52.
May be

In addition, the optical product assembling apparatus 10 is used to
If you can press and slide on the mount 56,
It is not limited to the waveguide member. For example, the optical fiber 72 (see FIGS. 9A and 9B) and the SELFOC lens 74 (see FIG. 9C) may be arranged on the second mount. Furthermore, as shown in FIG. 9C, a spherical optical fiber 76 or an aspherical lens 78 may be used. In addition, as shown in FIG. 9D, the first mount 52
The LD element array 80 may be placed on the second mount 54 and the optical fiber array 82 may be placed on the second mount 54.

Further, the wavelength conversion element 54 is replaced with the LD element 50.
However, the means for exerting an external force on the wavelength conversion element 54 at the time of face-to-face matching is not limited to the pin as in the present embodiment, but may be another work jig.

Further, the pressing force (elastic force) of the pressing member 18
Is provided by the coil spring 42 provided on the Y axis on the wavelength conversion element 54, but may be offset from the Y axis or may be provided by other means such as an air cylinder. The pressing member 18 may set the wavelength conversion element 54 so that it can be pressed either automatically or manually.

Further, when the adhesive 62 is unlikely to penetrate into the gap between the first mount 52 and the second mount 56, the gap should be set with the adhesive 62 applied to the corresponding surface in advance. Is also good.

The volume contraction rate of the adhesive 62 is not particularly limited, but is preferably smaller from the viewpoint of suppressing the gap variation. Although the adhesive 62 is made of a photocurable resin, the adhesive is not limited to this. That is, the anaerobic property, thermosetting property, application of a primer, and a composite adhesive of these are not particularly limited.

[0108]

According to the present invention, when assembling an optical product by positioning and fixing optical elements with high accuracy, it is possible to accurately form a gap between holding members for holding both optical elements and optical elements. You can As a result, optical products that are optically coupled with high efficiency can be assembled with a high yield.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an optical product assembling apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration perspective view of an optical product according to an embodiment of the present invention.

3A to 3D are side views showing an assembly process of an optical product according to an embodiment of the present invention.

4 (E) to (G) are side views showing an assembly process of an optical product according to an embodiment of the present invention.

5 (H) to (J) are side views showing an assembling process of the optical product according to the embodiment of the present invention.

6 (K) to (M) are side views showing an assembly process of an optical product according to an embodiment of the present invention.

7 (F) to (H) are plan views showing an assembling process of the optical product according to the embodiment of the present invention.

8 (J) to (L) are plan views showing an assembly process of the optical product according to the embodiment of the present invention.

9 (A) to 9 (D) show another embodiment of the present invention.

FIG. 10A is an explanatory diagram of a gap state at the time of setting, and FIG. 10B is an explanatory diagram of a gap state after the adhesive is cured.

FIG. 11 is a graph showing a distribution state of the final gap amount between the LD element and the wavelength conversion element according to the embodiment of the present invention.

FIG. 12 is a graph showing the relationship between the final gap amount and the coupling efficiency between the LD element and the wavelength conversion element according to the embodiment of the present invention.

[Explanation of symbols]

10 ... Optical product assembly device 12 ... Fixed stage (first fixing means) 14 ... Adjustment stage (second fixing means, adjusting means) 25 ... Support member (bending prevention means, support means) 50 ... LD element element (first optical element) 52 ... First mount (first holding member) 54 ... Wavelength conversion element (second optical element) 56 ... Second mount (second holding member)

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Claims (4)

[Claims] 1. A first holding member, to which a first optical element is fixed, and a second holding member, to which a second optical element on which the light emitted from the first optical element is incident, are fixed, are bonded together. In the method for assembling an optical product in which an optical element and a second optical element are optically coupled, the end surface of the first holding member to which the first optical element is fixed and the end surface of the first holding member are arranged in parallel to each other. A first step in which the distance between the end surfaces of the second holding member to which the optical element is fixed is D1, and the distance between the end surfaces of the first optical element and the second optical element, which are parallel to each other, is d0; A second step of joining the first holding member and the second holding member by applying an adhesive between the end surface of the first holding member and the end surface of the second holding member, Satisfying the relationship of d0> αD1 when the volume contraction rate is α The method of assembling an optical product, wherein the distance d0 is set as described above. 2. A first holding member, to which a first optical element is fixed, and a second holding member, to which a second optical element, to which the light emitted from the first optical element is incident, are fixed, are bonded together.
In the method for assembling an optical product in which an optical element and a second optical element are optically coupled, the end surface of the first holding member to which the first optical element is fixed and the end surface of the first holding member are arranged in parallel to each other. The distance from the end surface of the second holding member to which the optical element is fixed is D1.
And a first step in which the distance between the end surfaces of the first optical element and the end surface of the second optical element, which are parallel to each other, is set to d0, and the end surface of the first holding member and the end surface of the second holding member A second step of joining the first holding member and the second holding member by applying an adhesive therebetween, wherein the distance D1 is set so as to satisfy the relationship of 5 μm <D1 <30 μm. Optical product assembly method. 3. A first holding member, to which a first optical element is fixed, and a second holding member, to which a second optical element, on which the light emitted from the first optical element is incident, are fixed, are bonded together. In an optical product assembling method in which an optical element and a second optical element are optically coupled, an end surface of the first holding member to which the first optical element is fixed and a second holding member that is parallel to the end surface of the first holding member. After setting the distance from the end face of the member to D0, the second step of mounting the second optical element on the second holding member to make the end face of the second optical element parallel to the end face of the first optical element A second step of interposing an adhesive between the second optical element placed on the second holding member and the second holding member, and the second holding member is moved toward the first holding member by a distance D0. -D
A third step of moving the second optical element by 1 + d0 and bringing the second optical element into contact with the first optical element; A fourth optical element and a second holding member are bonded by curing the adhesive.
A fifth step of moving the second holding member away from the first holding member by a distance d0, and applying an adhesive agent between the end faces of the first holding member and the second holding member. A sixth step of joining the first holding member and the second holding member together, and a method of assembling an optical product. 4. A first holding member, to which a first optical element is fixed, and a second holding member, to which a second optical element on which the emitted light of the first optical element is incident, are fixed, are bonded together. In an optical product assembling apparatus that optically couples an optical element and a second optical element, a first fixing means that fixes a first holding member to which the first optical element is fixed, and a second fixing element that fixes the second optical element. Second fixing means for fixing the holding member, adjusting means for positioning and adjusting the second holding member fixed to the second fixing means with respect to the first holding member, and the second holding member by the adjusting means. The second optical element is placed on the second holding member after the second optical element placed on the second holding member comes into contact with the first optical element by approaching the first holding member to a predetermined distance. The second optical element so that A pressing means for pressing the second holding member, optical product assembly apparatus wherein comprising a deflection preventing means for preventing the first optical element deflects the second optical element upon contact.