JP2012079791A - Method for manufacturing optical semiconductor element module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical semiconductor element module capable of suppressing a displacement between optical axes of the optical semiconductor element and a lens caused by a heat shrinkage of a welded part on the laser irradiation in an aligning and fixing the optical axis of the optical semiconductor element module.SOLUTION: Optical axes of an optical semiconductor element 1 and a lens 3 are aligned and fixed, then two YAG welded parts 5 asymmetric relative to a center of the lens 3 are simultaneously irradiated with the laser. In a laser welding step for welding and fixing a lens holder 4 and a carrier 2, the laser irradiation is performed in the condition that the lens holder 4 is held by a lens holder fixture 61, and the movement of the lens holder 4 is limited. An abutment face 7 of the lens holder fixture 61 and a peripheral surface of the cylindrical lens holder 4 are in contact with each other at two lens holder contact parts 8 asymmetric relative to the center of the lens 3. This can suppress the displacement between optical axes of the optical semiconductor element 1 and the lens 3 caused by a heat shrinkage of a YAG welded part 5 on the laser irradiation, and the optical semiconductor element module can be accurately assembled.

Description

  The present invention relates to a method of manufacturing an optical semiconductor element module for optical communication, and more particularly to suppression of optical axis misalignment due to laser welding in optical axis alignment fixing of an optical semiconductor element and a lens.

  Conventionally, in the optical axis alignment fixing of the optical semiconductor element and the lens, the lens holder for holding the lens is supported by a jig, the optical semiconductor element mounted on the carrier and the optical axis of the lens are aligned, and then the YAG laser The carrier and the lens holder were fixed by welding. In this method, the optical axis shift between the optical semiconductor element and the lens accompanying a long-term temperature change is prevented by using the carrier and the lens holder as members having a small linear expansion coefficient.

  For example, in Patent Document 1, a laser diode module including a lens holder fixed by a fixing member arranged on a substrate, a laser diode arranged on the substrate, and a first lens held by the lens holder. In FIG. 3, the substrate and the fixing member, and the fixing member and the lens holder are joined by YAG laser welding. In this example, a material having a linear expansion coefficient equal to or less than a certain value is used as the material for the fixing member, so that the optical axis is not shifted and the occurrence of tracking errors is suppressed.

Japanese Patent Laid-Open No. 11-354892

  As described above, in the laser welding process in the optical axis alignment fixing of the conventional optical semiconductor element module, after aligning the optical axis of the optical semiconductor element and the lens, the carrier (substrate) and the lens on which the optical semiconductor element is mounted The lens holder that holds was fixed by welding by YAG laser welding.

  However, with the recent miniaturization of optical semiconductor element modules, individual optical components have become smaller, and the location (welded part) where the laser is irradiated is limited to an asymmetric position with respect to the center of the lens. I came. For this reason, there is a problem in that a non-uniform force is generated in the lens holder due to thermal contraction of the welded portion during laser irradiation, the lens is displaced from the optical axis alignment position, and the optical axis is shifted between the optical semiconductor element and the lens. .

  The present invention has been made to solve the above-described problems, and in the optical axis alignment fixing of the optical semiconductor element module, the optical axis of the optical semiconductor element and the lens due to the thermal contraction of the weld during laser irradiation. An object of the present invention is to provide a method of manufacturing an optical semiconductor element module capable of suppressing misalignment and enabling highly accurate assembly.

An optical semiconductor element module manufacturing method according to the present invention includes an optical semiconductor element mounted on a carrier, a lens arranged at a predetermined distance from the optical semiconductor element, and a lens that holds the lens and is fixed to the carrier by welding. A method for producing an optical semiconductor element module having a holder,
After aligning the optical axis of the optical semiconductor element and the lens while holding the lens holder with the lens holder fixing jig and restricting the movement of the lens holder, it is simultaneously applied to two laser welding parts that are asymmetric with respect to the center of the lens. A laser welding process is performed in which a laser is irradiated and the lens holder and the carrier are welded and fixed. The lens holder fixing jig is in contact with two lens holders that are asymmetric with respect to the center of the lens on a plane perpendicular to the center axis of the lens. The angle θ2 (which connects the two lens holder contact portions and the center of the lens) with respect to the angle θ1 (θ1 <180 °) between the laser welding portion and the center of the lens. θ2 <180 °) is larger, and θ1 is in a region where θ2 spreads.

  According to the method for manufacturing an optical semiconductor element module according to the present invention, after aligning the optical axis of the optical semiconductor element and the lens, simultaneously irradiate the laser welding portion at two points asymmetric with respect to the center of the lens, In the laser welding process of welding and fixing the lens holder and the carrier, the lens holder is held by the lens holder fixing jig and the laser irradiation is performed with the movement of the lens holder being restricted. An optical axis shift between the optical semiconductor element and the lens due to heat shrinkage can be suppressed, and the optical semiconductor element module can be assembled with high accuracy.

It is the schematic which shows the structure of the optical semiconductor element module which concerns on Embodiment 1 of this invention. It is a figure explaining the manufacturing method of the optical semiconductor element module which concerns on Embodiment 1 of this invention. It is a figure explaining the fixing method of the lens holder and a lens holder fixing jig in the manufacturing method of the optical semiconductor element module which concerns on Embodiment 1 of this invention. It is a figure explaining the shape of the lens holder fixing jig used in the manufacturing method of the optical semiconductor element module which concerns on Embodiment 1 of this invention. It is a figure explaining the manufacturing method of the optical semiconductor element module which concerns on Embodiment 2 of this invention. It is a figure explaining the manufacturing method of the optical semiconductor element module which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
Below, the manufacturing method of the optical semiconductor element module which concerns on Embodiment 1 of this invention is demonstrated based on drawing. 1A and 1B are schematic views showing the configuration of the optical semiconductor element module according to the first embodiment, where FIG. 1A is a front view, FIG. 1B is a top view, and FIG. 1C is a side view. In FIGS. 1A and 1C, the lens holder 4 shows a cross section.

  The optical semiconductor element 1 of the optical semiconductor element module is a light emitting semiconductor element that outputs near infrared light from the light emitting point A, and is mounted on the carrier 2. The lens 3 is disposed at a predetermined distance from the optical semiconductor element 1 and condenses near-infrared light output from the light emitting point A of the optical semiconductor element 1. A lens holder 4 that holds the lens 3 is fixed to the carrier 2 by welding. The lens 3 is press-fitted into the lens holder 4, and the positional relationship between them does not change. Further, the shape of the light emitting point A of the optical semiconductor element 1 is not particularly limited.

  The YAG laser welded portion 5 (hereinafter abbreviated as YAG welded portion 5) is a portion irradiated with a YAG laser in the optical axis alignment fixing of the optical semiconductor element module, and the bottom surface 4a of the lens holder 4 is in contact therewith. On the lens mounting surface 2 a of the carrier 2. As shown in FIG. 1 (b), the two YAG welded portions 5 are biased on one arc when the outer periphery of the bottom surface 4 a of the lens holder 4 is bisected, And asymmetrical position. In FIGS. 1A and 1C, the light emitting point A of the optical semiconductor element 1 and the center axis B of the lens 3 are shifted from each other. Then, the lens holder 4 and the carrier 2 are welded and fixed at the YAG welded part 5.

As the material of the carrier 2, Kovar (an alloy in which Fe and Ni are mixed), CuW, or the like having a linear expansion coefficient close to that of the optical semiconductor element 1 (for example, InP or InGaAs) is used. As the material of the lens holder 4, SUS, SF20T, or the like having a good absorption rate with respect to the wavelength of 1.06 μm of the YAG laser, that is, good weldability is used. Generally, a CO ₂ laser and a YAG laser are used for laser welding of metal materials. Other types of lasers include a second harmonic YAG laser (wavelength of 532 nm) and a semiconductor laser, but a low-power YAG laser is suitable for optical parts that require micron-order assembly.

  Next, a method for manufacturing the optical semiconductor element module according to the first embodiment will be described with reference to FIG. 2A and 2B are views for explaining an optical axis alignment fixing method of the optical semiconductor element module according to the first embodiment, where FIG. 2A is a top view and FIG. 2B is a side view. In addition, in FIG.2 (b), the lens holder 4 has shown the cross section. In FIG. 2, the same reference numerals are assigned to the same or corresponding parts as in FIG.

  In FIG. 2, the carrier 2 and the lens holder 4 are held by separate fixing members (not shown). These fixing members may also serve as positioning means. First, in the state where the lens holder 4 is held by the lens holder fixing jig 6 and the movement of the lens holder 4 is restricted, the optical semiconductor so that the light emitting point A of the optical semiconductor element 1 and the central axis B of the lens 3 coincide with each other. The positions of the element 1 and the lens 3 are adjusted. Adjustment of the positions of both the optical semiconductor element 1 and the lens 3 may be performed by moving the lens 3 with respect to the optical semiconductor element 1 or by moving the optical semiconductor element 1 with reference to the lens 3.

  After the optical axes of the optical semiconductor element 1 and the lens 3 are aligned, the laser beam is simultaneously applied to the two YAG welded portions 5 that are asymmetric with respect to the center of the lens 3 to fix the lens holder 4 and the carrier 2 by welding ( Laser welding process). If the two YAG welds 5 are asymmetric with respect to the center of the lens 3, the lens holder 4 is caused to have a non-uniform force due to thermal contraction of the YAG weld 5 during laser irradiation, so that the lens 3 is aligned with the optical axis alignment position. The optical axis of the optical semiconductor element 1 and the lens 3 may be displaced. In order to suppress such an optical axis shift, the lens holder 4 is held by the lens holder fixing jig 6 and laser irradiation is performed in a state where the movement of the lens holder 4 is restricted.

  The lens holder fixing jig 6 is provided with a contact surface 7 for restricting the movement of the lens holder 4. The contact surface 7 and the peripheral surface of the cylindrical lens holder 4 are in contact with two lens holder contact portions 8 that are asymmetric with respect to the center of the lens 3. When viewed on a plane perpendicular to the central axis of the lens 3, as shown in FIG. 2A, the lens holder 4 comes into contact with the lens holder contact portion 8 at two points asymmetric with respect to the center of the lens 3. I can say that. Furthermore, with respect to an angle θ1 (θ1 <180 °) connecting the two YAG welded portions 5 and the center of the lens 3, an angle θ2 (θ2 <θ) connecting the two lens holder contact portions 8 and the center of the lens 3 is used. 180 [deg.] Is larger, and [theta] 1 is in the area of [theta] 2. Thereby, even when the YAG welded portion 5 is thermally contracted at the time of laser irradiation, the lens holder 4 is held by the lens holder contact portion 8, so that the lens 3 can be prevented from being displaced from the optical axis alignment position.

  2B, the YAG welded portion 5 is on the lens mounting surface 2a of the carrier 2 in contact with the bottom surface 4a of the lens holder 4, and the lens holder fixing jig 6 is a lens holder. 4 is held above the peripheral surface. Thereby, the lens holder fixing jig 6 does not hinder laser irradiation during YAG laser welding. The shape and dimensions of the lens holder fixing jig 6 will be described later with reference to FIG.

  Next, a method of fixing the lens holder 4 with the lens holder fixing jig 6 will be described with reference to FIG. FIG. 3A shows a case where the lens holder 4 is made of a metal material and the lens holder fixing jig 6 is made of a nonmagnetic material. The lens holder fixing jig 6 has a support bar 9 magnetized by a magnet 10, and a part of the peripheral surface of the lens holder 4 is attracted and fixed by the magnetic force of the support bar 9, and the lens on the contact surface 7 is fixed. The lens holder 4 is held in the holder contact portion 8.

  FIG. 3B shows a case where the lens holder 4 is made of a metal material and the lens holder fixing jig 6 is made of a magnetic material. The lens holder fixing jig 6 is magnetized by the magnet 10 and adsorbs and fixes a part of the peripheral surface of the lens holder 4 by the magnetic force, and holds the lens holder 4 at the lens holder contact portion 8 of the contact surface 7. Yes. However, the method of fixing the lens holder 4 with the lens holder fixing jig 6 is not limited to this, and other methods may be used.

  Next, the shape and dimensions of the lens holder fixing jig 6 will be described with reference to FIG. FIG. 4A is a diagram showing a positional relationship among the optical semiconductor element, the carrier, the lens, and the YAG welded portion, and the lens holder fixing jig is not shown. Moreover, FIG.4 (b) is the front view which looked at the cross section in the CD line from the arrow direction in Fig.4 (a). In FIG. 4, the same reference numerals are assigned to the same or corresponding parts as in FIG.

  As shown in FIG. 4A, the distance from the light emitting point A of the optical semiconductor element 1 to the optical semiconductor element mounting surface 2b of the carrier 2 is L1, and the distance from the optical semiconductor element mounting surface 2b of the carrier 2 to the YAG weld 5 When the distance is L2 and the diameter of the lens holder 4 is d1, the angle θ1 when the two YAG welds 5 and the center of the lens 3 are connected can be obtained from the following formula 1 (in formulas 1 and 3, θ represents θ1). The angle of the contact surface 7 of the lens holder fixing jig 6 is set to an angle larger than θ1.

  Further, as shown in FIG. 4B, when the height of the contact surface 7 of the lens holder fixing jig 6 is h1, h1 is obtained from the following formula 2. In Equation 2, h2 is the height of the lens holder 4, d2 is the beam diameter of the YAG laser, Ψ is the YAG laser irradiation angle, and L3 is the distance from the side surface 6a of the lens holder fixing jig 6 to the YAG welded portion 5. In addition, L3 is calculated | required from following Numerical formula 3. In Formula 3, L4 is the width of the lens holder fixing jig 6. For example, if L1 is 0.4 mm, L2 is 0.4 mm, d1 is 2 mm, h2 is 1.2 mm, L4 is 2 mm, and Ψ is 45 °, h1 is 0.52 mm or less from the following Equation 2 and Equation 3. .

  As described above, according to the method for manufacturing the optical semiconductor element module according to the first embodiment, after the optical axes of the optical semiconductor element 1 and the lens 3 are aligned, two points asymmetric with respect to the center of the lens 3 are obtained. In the laser welding process of simultaneously irradiating the YAG welded portion 5 of the laser with the laser and welding and fixing the lens holder 4 and the carrier 2, the lens holder 4 is held by the lens holder fixing jig 6 and the movement of the lens holder 4 is restricted. Since the laser irradiation is performed by the laser beam, the optical axis shift between the optical semiconductor element 1 and the lens 3 due to the thermal contraction of the YAG welded part 5 at the time of laser irradiation can be suppressed, and the optical semiconductor element module can be assembled with high accuracy. Is possible.

Embodiment 2. FIG.
5A and 5B are diagrams for explaining an optical axis alignment fixing method for an optical semiconductor element module according to Embodiment 2 of the present invention, where FIG. 5A is a top view and FIG. 5B is a side view. In the top view of FIG. 5A, the dotted line indicates a portion that is not actually seen. Moreover, in FIG.5 (b), the lens holder 4 has shown the cross section. Further, in FIG. 5, the same reference numerals are assigned to the same and corresponding parts as in FIG.

  Also in the second embodiment, as in the first embodiment, after the optical axes of the optical semiconductor element 1 and the lens 3 are aligned, the two YAG welds 5 that are asymmetric with respect to the center of the lens 3 are formed. At the same time, the laser is irradiated to fix the lens holder 4 and the carrier 2 by welding. In order to suppress the optical axis shift due to the thermal contraction of the YAG welded portion 5 at the time of laser irradiation, the lens holder 4 is held by the lens holder fixing jig 61, and laser irradiation is performed with the movement of the lens holder 4 restricted. .

  A method of fixing the lens holder 4 using the lens holder fixing jig 61 according to the second embodiment will be described with reference to FIG. As shown in FIG. 5A, the lens holder fixing jig 61 is provided with a contact surface 7 for restricting the movement of the lens holder 4. The contact surface 7 and the peripheral surface of the cylindrical lens holder 4 are in contact with two lens holder contact portions 8 that are asymmetric with respect to the center of the lens 3. Since the positional relationship between the YAG welded portion 5 and the lens holder contact portion 8 is the same as that in the first embodiment, description thereof is omitted.

  In the first embodiment, the lens holder fixing jig 6 attracts and fixes the lens holder 4 by the magnetic force of the magnet 10 (see FIG. 3). In the second embodiment, FIG. As shown, the lens holder fixing jig 61 has a suction surface 11 for vacuum-sucking the lens holder 4, and a part of the lens holder 4 (upper surface in FIG. 5) is sucked and fixed by the suction surface 11. The lens holder 4 is held in the lens holder contact portion 8.

  6 shows another configuration example of the lens holder fixing jig used in the second embodiment, where (a) is a top view and (b) is a side view. In the top view of FIG. 6A, the dotted line indicates a portion that is not actually seen. Moreover, in FIG.6 (b), the lens holder 4 has shown the cross section. Further, in FIG. 6, the same reference numerals are assigned to the same and corresponding parts as in FIG.

  As shown in FIG. 6A, the lens holder fixing jig 62 is provided with a contact pin 12 for restricting the movement of the lens holder 4. The shape of the contact pin 12 is cylindrical in FIG. 6, but is not particularly limited. The contact pins 12 and the peripheral surface of the cylindrical lens holder 4 are in contact with two lens holder contact portions 8 that are asymmetric with respect to the center of the lens 3. The positional relationship between the YAG welded part 5 and the lens holder contact part 8 is the same as in the first embodiment.

  As shown in FIG. 6B, the lens holder fixing jig 62 has a suction surface 11 for vacuum-sucking the lens holder 4, and the suction surface 11 sucks and fixes the upper surface of the lens holder 4. At the same time, the lens holder 4 is held in the lens holder contact portion 8.

  According to the method for manufacturing an optical semiconductor element module according to the second embodiment, in addition to the same effects as those of the first embodiment, the upper surface of the lens holder 4 is provided on the suction surface provided on the lens holder fixing jigs 61 and 62. 11, the inclination of the lens holder 4 with respect to the carrier 2 can be suppressed, and assembly with higher accuracy is possible.

  In the first embodiment and the second embodiment, the example in which the light emitting semiconductor element is used as the optical semiconductor element 1 has been described. However, the optical semiconductor element module according to the present invention uses a light receiving semiconductor element. May be. In this case, a lens that collects near-infrared light from the outside and makes it incident on the light receiving point of the light receiving semiconductor element is used.

  INDUSTRIAL APPLICABILITY The present invention can be used as a method for manufacturing an optical semiconductor element module for optical communication, particularly as an optical axis alignment fixing method for optical semiconductor elements and lenses.

1 optical semiconductor element, 2 carrier, 2a lens mounting surface,
2b Optical semiconductor element mounting surface, 3 lens, 4 lens holder, 4a bottom surface,
5 YAG laser weld, 6, 61, 62 Lens holder fixing jig,
7 contact surface, 8 lens holder contact portion, 9 support bar, 10 magnet,
11 adsorption surface, 12 contact pin.

Claims (7)

An optical semiconductor element module manufacturing method comprising: an optical semiconductor element mounted on a carrier; a lens disposed at a predetermined distance from the optical semiconductor element; and a lens holder that holds the lens and is fixed to the carrier by welding. Because
After aligning the optical axis of the optical semiconductor element and the lens in a state where the lens holder is held by a lens holder fixing jig and the movement of the lens holder is restricted, two points asymmetric with respect to the center of the lens A laser welding process of simultaneously irradiating a laser welding portion with a laser and welding and fixing the lens holder and the carrier;
The lens holder fixing jig is in contact with the lens holder at two lens holder contact portions that are asymmetric with respect to the center of the lens on a plane perpendicular to the center axis of the lens, and the two laser welding portions And the angle θ2 (θ2 <180 °) connecting the two lens holder contact portions and the center of the lens is larger than the angle θ1 (θ1 <180 °) connecting the center of the lens and the center of the lens, and A method of manufacturing an optical semiconductor element module, wherein θ1 is in a region where θ2 spreads.   2. The method of manufacturing an optical semiconductor element module according to claim 1, wherein the lens holder is made of a metal material, the lens holder fixing jig is made of a nonmagnetic material, and the lens holder fixing jig is magnetized by a magnet. A method for manufacturing an optical semiconductor element module, comprising: a support rod; and a part of the lens holder is attracted and fixed by the magnetic force of the support rod, and the lens holder is held at the lens holder contact portion. .   2. The method of manufacturing an optical semiconductor element module according to claim 1, wherein the lens holder is made of a metal material, the lens holder fixing jig is made of a magnetic material, and the lens holder fixing jig is magnetized by a magnet, A part of the lens holder is attracted and fixed by magnetic force, and the lens holder is held in the lens holder contact portion.   The method of manufacturing an optical semiconductor element module according to claim 1, wherein the lens holder fixing jig has a suction surface for vacuum-sucking the lens holder, and a part of the lens holder is sucked by the suction surface. And fixing the lens holder, and holding the lens holder at the lens holder contact portion.   2. The method of manufacturing an optical semiconductor element module according to claim 1, wherein the optical semiconductor element is a light emitting semiconductor element that outputs near-infrared light from a light emitting point thereof, and the lens is output from the light emitting semiconductor element. For manufacturing an optical semiconductor element module, characterized in that a lens for condensing near infrared light is used.   2. The method of manufacturing an optical semiconductor element module according to claim 1, wherein a light receiving semiconductor element that receives near-infrared light from outside is used as the optical semiconductor element, and near-infrared light from outside is used as the lens. A method of manufacturing an optical semiconductor element module, wherein a lens that collects light and enters the light receiving point of the light receiving semiconductor element is used.   2. The method of manufacturing an optical semiconductor element module according to claim 1, wherein a YAG laser is used in the laser welding process.

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