JP2014027096A - Optical module and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the deviation between an optical axis of a package including a semiconductor optical element and a lens and an optical axis of a sleeve.SOLUTION: An optical module 1A comprises a package 10 and a sleeve 20. A package insertion hole 24 of the sleeve 20 includes a first portion 24a and a second portion 24b facing a surface of the package 10. An inner diameter D2 of the second portion 24b is smaller than an inner diameter D1 of the first portion 24a. The sleeve 20 includes a plurality of slits 26 formed side by side in a circumferential direction of the package insertion hole 24. An ultraviolet curing resin 31 is arranged in a gap between the second portion 24b and the package 10. A thermosetting resin 32 is arranged in a gap between a peripheral part of the plurality of slits 26 and the package 10. A thixotropy value of the thermosetting resin 32 is not less than 1.6 and not more than 3.0.

Description

  The present invention relates to an optical module and an optical module manufacturing method.

  Patent Document 1 describes a resin-sealed optical module. This resin-encapsulated optical module includes an optical semiconductor element, a lens, and an optical fiber. The optical semiconductor element and the optical fiber are optically coupled to each other by a lens. The space between the optical semiconductor element and the lens is filled with a transparent resin.

  Patent Document 2 describes a method of manufacturing an optical module for reliably and strengthening the adhesion between the optical device and the sleeve. This manufacturing method includes a first bonding step in which the optical device and the sleeve are temporarily fixed using an ultraviolet curable resin, and a second bonding in which the optical device and the sleeve are permanently fixed using a thermosetting resin. Process.

  Patent Document 3 describes a method for manufacturing an optical module in which a light emitting element and a lens are fixed by a resin mold. In this manufacturing method, a lead frame on which a light emitting element is mounted and a glass lens member are disposed in a cavity of a molding die, and a resin mold is formed by injecting molten resin into the cavity.

JP 2004-133117 A JP 2011-044595 A JP 2012-033858 A

  An optical module used for optically coupling a semiconductor optical device and an optical fiber has a structure in which a package including the semiconductor optical device and a lens is bonded and fixed to one end of a sleeve, and the optical fiber is inserted from the other end of the sleeve. There is. When manufacturing such an optical module, it is desired that the optical axis of the package and the optical axis of the sleeve be accurately aligned. However, depending on the application state of the adhesive for fixing the package to the sleeve, the optical axis of the package There is a problem that the shaft and the optical axis of the sleeve shift. Such deviation of the optical axis is caused not only by an excessive amount of adhesive applied but also by flow of the adhesive before or during curing of the adhesive.

  The present invention has been made in view of such problems, and an optical module and an optical module that can reduce the deviation between the optical axis of the package including the semiconductor optical element and the lens and the optical axis of the sleeve. It aims to provide a method.

  In order to solve the above-described problems, an optical module according to the present invention is an optical module that optically couples a semiconductor optical element and an optical fiber, and includes a semiconductor optical element and a lens optically coupled to the semiconductor optical element, A package having a columnar portion, a cylindrical shape extending in a predetermined direction, an optical fiber insertion hole for receiving an end of the optical fiber is formed on one end side in the predetermined direction, and the end of the optical fiber, the semiconductor optical element, And a sleeve having a package insertion hole formed on the other end side in a predetermined direction for receiving the cylindrical portion of the package so that the cylindrical insertion portions are optically coupled to each other through the lens, and the package insertion hole faces the cylindrical portion. A first portion having a first inner diameter, and a second inner diameter located on the other end side in a predetermined direction with respect to the first portion and facing the cylindrical portion and being smaller than the first inner diameter. The sleeve has a plurality of slits formed side by side in the circumferential direction of the package insertion hole, and is disposed in a gap between the second portion and the cylindrical portion. The thermosetting resin further includes an ultraviolet curable resin that adheres the sleeve and the package to each other, and a thermosetting resin that is disposed in a gap between the peripheral portion of the plurality of slits and the cylindrical portion and adheres the sleeve and the package to each other. The thixo value of the mold resin is 1.6 or more and 3.0 or less.

  An optical module manufacturing method according to the present invention is an optical module manufacturing method for optically coupling a semiconductor optical device and an optical fiber, and includes a semiconductor optical device and a lens optically coupled to the semiconductor optical device. The cylindrical portion of the package having a cylindrical portion has a cylindrical shape extending in a predetermined direction, and an optical fiber insertion hole for receiving an end portion of the optical fiber is formed on one end side in the predetermined direction. A package insertion hole for receiving a cylindrical portion of the package is inserted into a package insertion hole formed on the other end side in a predetermined direction so that the semiconductor optical element is optically coupled to each other via a lens, and the package and the sleeve The package insertion hole is opposed to the columnar portion and has a first inner diameter and a predetermined direction with respect to the first portion. And a second portion having a second inner diameter that is smaller than the first inner diameter and is opposed to the cylindrical portion, and the sleeves are arranged in the circumferential direction of the package insertion hole. A first step of adhering the sleeve and the package to each other by disposing an ultraviolet curable resin in the gap between the second portion and the columnar portion; After the first step, there is a second step in which the thermosetting resin is disposed in the gaps between the peripheral edge portions of the plurality of slits and the cylindrical portion, and the sleeve and the package are bonded to each other. The thixo value is 1.6 or more and 3.0 or less.

  When manufacturing an optical module, first, an ultraviolet curable resin is placed between the package and the sleeve and cured (temporary fixing), and then a thermosetting resin is placed in the slit and cured (main fixing). Thus, the package and the sleeve are firmly fixed. However, in the conventional optical module, since these resins are sucked up by the capillary phenomenon in the gap between the package and the sleeve, these resins may overflow other than the desired bonding location. When such a phenomenon occurs, the arrangement of the resin becomes non-uniform and the optical axis between the package and the sleeve shifts.

  On the other hand, in the optical module and the method for manufacturing the optical module, the package insertion hole is formed on the first portion and the other end side in the predetermined direction with respect to the first portion (the side where the package insertion port is provided). A second portion located. The first and second portions oppose the cylindrical portion of the package and have first and second inner diameters, respectively. The second inner diameter is smaller than the first inner diameter. In the package insertion hole having such a shape, the suction due to the capillary action described above stops at the second portion, and hardly reaches the other portion of the package insertion hole. Therefore, the arrangement of the ultraviolet curable resin and the thermosetting resin can be made uniform, and the shift of the optical axis between the package and the sleeve can be effectively reduced.

  Further, in the conventional optical module, the placement of the adhesive may be biased before the thermosetting resin is cured during the main fixing. Such an uneven arrangement of the thermosetting resin also causes a deviation of the optical axis between the package and the sleeve. In contrast, in the optical module and the optical module manufacturing method described above, the thixo value of the thermosetting resin is 1.6 or more and 3.0 or less. The inventor of the present invention can reduce the deviation of the arrangement of the thermosetting resin when the thixo value of the thermosetting resin is within such a range, and the semiconductor optical element caused by the optical axis deviation between the package and the sleeve And found that the optical loss between the optical fiber and the optical fiber is reduced. That is, according to the optical module and the method for manufacturing the optical module, the deviation between the optical axis of the package and the optical axis of the sleeve can be further effectively reduced.

  The optical module may be characterized in that the package is formed by molding using a light-transmitting resin. Similarly, in the method for manufacturing an optical module, the preparation step may include a step of forming a package by molding using a translucent resin.

  According to the optical module and the optical module manufacturing method of the present invention, it is possible to reduce the deviation between the optical axis of the package including the semiconductor optical element and the lens and the optical axis of the sleeve.

FIG. 1 is a perspective view showing an appearance of an optical module according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II of the optical module shown in FIG. 1, and shows a side cross section along the optical axis direction. FIG. 3 is a cross-sectional view of the optical module shown in FIG. 1 taken along line III-III, showing a cross section perpendicular to the optical axis direction. FIG. 4 is a perspective view illustrating an appearance of a sleeve according to an embodiment. FIG. 5 is a cutaway perspective view of the sleeve cut out along the central axis direction. FIG. 6 is a flowchart showing details of the manufacturing method of the optical module. FIG. 7 is a diagram illustrating a structure of a molding die used when manufacturing a package according to an embodiment. FIG. 7A shows a cross section of the molding die along the direction of the optical axis of the semiconductor optical device. FIG. 7B shows a cross section of the molding die perpendicular to the optical axis (cross section VII-VII in FIG. 7A). FIG. 8 is a perspective view showing an appearance of a sleeve according to a modification.

  Embodiments of an optical module and an optical module manufacturing method according to the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a perspective view showing an external appearance of an optical module 1A according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II of the optical module 1A shown in FIG. 1, and shows a side cross section along the optical axis direction. FIG. 3 is a cross-sectional view taken along line III-III of the optical module 1A shown in FIG. 1 and shows a cross section perpendicular to the optical axis direction.

  The optical module 1 </ b> A of the present embodiment is a component for optically coupling the semiconductor optical device 40 and the optical fiber 50. The semiconductor optical element 40 is a light emitting element such as a laser diode or a light emitting diode when the optical module 1A is an optical transmission module, and a light receiving element such as a photodiode when the optical module 1A is an optical receiving module. . The optical fiber 50 is, for example, a single mode optical fiber for optical communication. When the optical module 1A is an optical transmission / reception module, the semiconductor optical element 40 includes two elements such as a light emitting element and a light receiving element. A substantially cylindrical ferrule 51 is mounted coaxially with the optical fiber 50 at the end of the optical fiber 50.

  As shown in FIGS. 1 to 3, the optical module 1 </ b> A has a substantially cylindrical appearance with the optical axis of the optical fiber 50 as a central axis, and includes a package 10 and a sleeve 20.

  The package 10 is a member including a semiconductor optical device 40, a lead frame 11 on which the semiconductor optical device 40 is mounted, and a ball lens 12 that is optically coupled to the semiconductor optical device 40. The package 10 has an appearance including a cylindrical portion having a central axis common to the central axis of the optical module 1A. In the present embodiment, most of the portion is formed in a substantially cylindrical shape. The outer diameter of the cylindrical portion of the package 10 is, for example, 4.3 mm, and the length in the central axis direction is, for example, 6.0 mm.

  As will be described later, the package 10 is preferably formed by molding using a translucent resin. As the translucent resin, for example, NT series manufactured by Nitto Denko (main components: modified epoxy and acid anhydride) is suitable. In addition, a resin lens 13 is preferably formed on the optical axis of the package 10. The refractive index of the resin lens 13 is 1.51, for example. The semiconductor optical device 40 is mounted on a submount 41 provided on the lead frame 11, for example.

  The lead frame 11 is made of a copper alloy such as KFC (registered trademark). The ball lens 12 is a spherical lens made of glass such as TAF3, and has a refractive index higher than that of the translucent resin. When the ball lens 12 is made of TAF3, its refractive index is about 1.78. The diameter of the ball lens 12 is 0.8 mm, for example. Further, the distance between the semiconductor optical element 40 and the ball lens 12 is, for example, 0.325 mm, the distance between the ball lens 12 and the resin lens 13 is, for example, 0.545 mm, and the resin lens 13 and the optical fiber 50. The distance between is, for example, 2.38 mm.

  The sleeve 20 is a cylindrical member extending in a predetermined direction A along the optical axis of the optical fiber 50. The sleeve 20 may be made of a metal such as SUS, or may be made of a resin such as polyetherimide or LCP (Liquid Crystal Polymer).

  Here, FIG. 4 is a perspective view showing an appearance of the sleeve 20 of the present embodiment, and FIG. 5 is a cutaway perspective view in which the sleeve 20 is cut out along the central axis direction. As shown in FIGS. 4 and 5, in the sleeve 20, an optical fiber fixing portion 21 that fixes the optical fiber 50 and a package fixing portion 22 that fixes the package 10 are integrated side by side in the predetermined direction A. It has a configuration. The length of the optical fiber fixing portion 21 in the predetermined direction A is, for example, 4.0 mm, the length of the package fixing portion 22 in the same direction is, for example, 5.4 mm, and the outer diameter of the package fixing portion 22 is, for example, 6.8 mm. It is. As shown in FIG. 2, an optical fiber insertion hole 23 is formed in the optical fiber fixing portion 21 of the sleeve 20, and a package insertion hole 24 is formed in the package fixing portion 22 of the sleeve 20.

  The optical fiber insertion hole 23 is formed on one end side in the predetermined direction A in the sleeve 20 and receives one end portion of the optical fiber 50 together with the ferrule 51 (see FIG. 2). The optical fiber insertion hole 23 is a bottomed hole having a circular cross section with the optical axis of the optical fiber 50 as the central axis.

  The package insertion hole 24 is formed on the other end side in the predetermined direction A in the sleeve 20 and receives the cylindrical portion of the package 10 (see FIG. 2). The package insertion hole 24 is a bottomed hole having a circular cross section with the optical axis of the package 10 as the central axis. In the present embodiment, the optical axis of the package 10 and the optical axis of the optical fiber 50 coincide with each other. As shown in FIG. 2, the package insertion hole 24 receives the package 10 such that the end of the optical fiber 50 and the semiconductor optical device 40 are optically coupled to each other via the ball lens 12. The package insertion hole 24 and the optical fiber insertion hole 23 communicate with each other through a through hole 25 for allowing light to pass therethrough.

  In the present embodiment, the package insertion hole 24 has a first portion 24a and a second portion 24b. The first portion 24a faces the columnar portion of the package 10 and has an inner diameter D1. The second portion 24b faces the cylindrical portion of the package 10 and has an inner diameter D2. The second portion 24b is located on the other end side in the predetermined direction A with respect to the first portion 24a. In other words, the first portion 24 a is located between the second portion 24 b and the optical fiber insertion hole 23.

  The inner diameter D2 of the second portion 24b is smaller than the inner diameter D1 of the first portion 24a. Therefore, when the first portion 24a and the second portion 24b are continuous as in the present embodiment, a step is generated at the boundary portion between the first portion 24a and the second portion 24b. The width of the gap between the cylindrical portion of the package 10 and the package insertion hole 24 changes with this step as a boundary.

  Further, the sleeve 20 of the present embodiment has a plurality of (three in the figure) slits 26. The plurality of slits 26 are formed at equal intervals in the circumferential direction of the package insertion hole 24 (that is, the direction around the optical axis of the package 10). Specifically, the slit 26 is formed as a notch having a finite length in the predetermined direction A from the other end surface of the package fixing portion 22 in the predetermined direction A, that is, in the central axis direction of the package insertion hole 24, and its planar shape Is, for example, U-shaped. The planar shape of the slit 26 is not limited to a U shape, and may be a V shape, a rectangle, an ellipse, or the like. The optical fiber fixing part 21 and the package fixing part 22 may be constituted by different members.

  Refer to FIGS. 2 and 3 again. As shown in these drawings, the optical module 1A further includes an ultraviolet curable resin 31 for temporary fixing and a thermosetting resin (reinforcing resin) 32 for main fixing. The ultraviolet curable resin 31 and the thermosetting resin 32 are adhesives arranged in the gap between the package 10 and the sleeve 20 in order to bond and fix the package 10 and the sleeve 20 to each other. The ultraviolet curable resin 31 is disposed in the gap between the second portion 24 b of the sleeve 20 and the cylindrical portion of the package 10. Further, the thermosetting resin 32 is disposed in a gap between the peripheral edge portions of the plurality of slits 26 in the sleeve 20 and the cylindrical portion of the package 10. As will be described later, the thixo values before curing of the ultraviolet curable resin 31 and the thermosetting resin 32 are preferably 1.6 or more and 3.0 or less. Such a thixo value is suitably adjusted by increasing or decreasing the amount of silica filler added to the ultraviolet curable resin 31 and the thermosetting resin 32, for example. The viscosity of the ultraviolet curable resin 31 before curing is, for example, 10,000 cps to 30000 cps, and the viscosity of the thermosetting resin 32 before curing is, for example, 10,000 cps or more. An example of the ultraviolet curable resin 31 is a photo / thermosetting epoxy resin (for example, optical adhesive 3400 series manufactured by EMI, etc.) in which a cationic polymerization initiator is blended.

  A method of manufacturing the optical module 1A having the above configuration will be described. FIG. 6 is a flowchart showing details of the manufacturing method of the optical module 1A.

  First, the package 10 and the sleeve 20 having the above-described configuration are prepared (S11 in FIG. 6). Here, the package 10 is suitably manufactured by the following method, for example. FIG. 7 is a view showing a structure of a molding die 60 used when manufacturing the package 10 of the present embodiment, and FIG. 7A is a molding along the direction of the optical axis of the semiconductor optical device 40. FIG. FIG. 7B shows a cross section of the molding die 60 perpendicular to the optical axis (VII-VII cross section in FIG. 7A). In FIG. 7, the lead frame 11, the ball lens 12, the semiconductor optical device 40, and the submount 41 are shown together.

  The package 10 of the present embodiment is preferably formed by using a translucent resin, for example, by transfer molding. An example of the transfer mold molding machine used is a transfer mold molding machine (MY-20) manufactured by Sumitomo Heavy Industries.

  As shown in FIG. 7, the molding die 60 has a lower die 62 and an upper die 63. The lower mold 62 is formed with a recess 62a, a lead frame holding part 62b, and a positioning pin 64. The concave portion 62 a has a shape for forming the resin lens 13 of the package 10. The lead frame holding part 62 b has a shape for holding the lead frame 11. The positioning pin 64 positions the ball lens 12 from the lower side in the cavity 66, has a substantially truncated cone shape as a whole, and is formed so as to protrude from the bottom of the lower mold 62. The tip portion of the positioning pin 64 has a spherical concave shape that matches the shape of the ball lens 12. Thereby, the positioning pin 64 can place the ball lens 12 on the tip thereof.

  The upper mold 63 is formed with a recess 63a and a positioning pin 65. The recess 63 a has a shape for forming the resin lens 13 of the package 10. The positioning pin 65 is for positioning the ball lens 12 at a predetermined position of the cavity 66 from the upper side, has the same shape as the positioning pin 64, and is formed to project at a corresponding position.

  When manufacturing the package 10, first, the lead frame 11 is placed on the lead frame holding portion 62 b of the lower mold 62, and the ball lens 12 is placed on the tip of the positioning pin 64 protruding from the lower mold 62. . Then, by closing the upper mold 63, the ball lens 12 is positioned and held from above by the positioning pins 65 of the upper mold 63.

  Then, a molding die 60 is mounted inside a transfer mold press machine (not shown), and transparent resin press molding is performed. In press molding, the cavity 66 is evacuated to suppress the generation of holes, and the molten resin that has been heated and fluidized is pressurized and injected into the cavity 66. Then, the molded package 10 is taken out after predetermined curing conditions are completed. Thereafter, if necessary, heat curing (post cure) is performed at 150 to 165 ° C. for 2 to 3 hours in order to make the cured state of the light transmitting resin of the package 10 more complete. Through the above steps, the package 10 of the present embodiment is suitably manufactured.

  After the package 10 is manufactured in this way, the package 10 and the sleeve 20 are aligned (alignment process, S12). Specifically, the optical fiber 50 is inserted into the optical fiber insertion hole 23 simultaneously with the insertion of the package 10 into the package insertion hole 24 of the sleeve 20. Next, when the semiconductor optical device 40 is a light emitting device, the intensity of light emitted from the other end of the optical fiber 50 is measured while outputting light from the semiconductor optical device 40. When the semiconductor optical element 40 is a light receiving element, the intensity of light incident on the semiconductor optical element 40 is measured in the semiconductor optical element 40 while inputting light from the other end of the optical fiber 50. Then, the relative position between the package 10 and the sleeve 20 when the light intensity becomes maximum is found, and the relative position is recorded.

  Subsequently, the cylindrical portion of the package 10 is inserted into the package insertion hole 24 of the sleeve 20, and the package 10 and the sleeve 20 are separated by the ultraviolet curable resin 31 and the thermosetting resin 32 shown in FIGS. 2 and 3. Are bonded (bonding step, S13 in FIG. 6).

  Here, the bonding step S13 includes a first step S131 and a second step S132. In the first step S131, the ultraviolet curable resin 31 is disposed and cured in the gap between the second portion 24b of the package insertion hole 24 and the cylindrical portion of the package 10, thereby temporarily fixing the package 10 and the sleeve 20. This is a process of fixing. In the second step S132, the thermosetting resin 32 is disposed in the gap between the peripheral edge of the slit 26 of the package insertion hole 24 and the cylindrical portion of the package 10 and cured, so that the package 10 and the sleeve 20 This is the step of performing the actual fixing.

  Hereinafter, the details of the bonding step S13 will be described. When the sleeve 20 and the package 10 are aligned and bonded, first, the ultraviolet curing resin 31 is used to temporarily fix the sleeve 20 and the package 10 (first step, S131). Here, the ultraviolet curable resin 31 is applied to the side surface of the package 10 facing the second portion 24 b of the package insertion hole 24, and the package 10 is inserted into the package insertion hole 24. At this time, the ultraviolet curable resin 31 is not applied to the entire side surface of the package 10, but may be applied in a spot manner at a plurality of locations (for example, 3 locations). The application amount of the ultraviolet curable resin 31 may be, for example, about 1.0 mg to 4.0 mg per place.

  Next, the relative position between the package 10 and the sleeve 20 is matched with the relative position recorded in the alignment step S12 described above. Then, the ultraviolet curable resin 31 is cured by irradiating the package 10 and the sleeve 20 with ultraviolet rays. At this time, ultraviolet rays can be irradiated from the side surface and the back surface of the sleeve 20 through the slit 26. The intensity of ultraviolet rays is, for example, 5000 mJ to 60000 mJ.

  After performing the first step S <b> 131 with the ultraviolet curable resin 31, the thermosetting resin 32 is applied to the gap between the package 10 and the package insertion hole 24 at the periphery of the slit 26. Thereafter, the sleeve 20 and the package 10 are accommodated in a constant temperature bath under predetermined conditions, and the thermosetting resin 32 is cured by performing heat curing. In this way, the sleeve 20 and the package 10 are permanently fixed (second step, S132). In the second step S132, since the curing reaction further proceeds in the ultraviolet curable resin 31, the adhesive strength of the ultraviolet curable resin 31 can be further increased. The heating conditions in the second step S132 are, for example, 60 to 155 ° C. and 15 to 120 minutes. From the viewpoint of adjusting the resin composition of the adhesive and desired mechanical properties, the curing temperature and the curing time are appropriately set. An example of the heating condition is 15 minutes at 155 ° C.

  In the bonding step S13 described above, the optical coupling efficiency between the semiconductor optical device 40 and the optical fiber 50 may be monitored by the same method as in the alignment step S12. The optical coupling efficiency is preferably within ± 0.5 dB after the bonding step S13 as compared to the optical coupling loss before the bonding step.

  The effects obtained by the optical module 1A according to the present embodiment described above and the manufacturing method thereof will be described. As described above, when the adhesive sucks up the gap between the package and the sleeve by capillary action, the adhesive overflows in areas other than the desired bonding location. When such a phenomenon occurs, the arrangement of the adhesive becomes non-uniform and the optical axis between the package and the sleeve is displaced.

  With respect to such conventional problems, in the optical module 1A and the manufacturing method thereof according to the present embodiment, the package insertion hole 24 has the first portion 24a and the other end in the predetermined direction A with respect to the first portion 24a. And a second portion 24b located on the side. The first and second portions 24a and 24b face the cylindrical portion of the package 10, and the inner diameter D2 of the second portion 24b is smaller than the inner diameter D1 of the first portion 24a. In the package insertion hole 24 having such a shape, suction due to capillary action mainly occurs in the second portion 24b where the gap between the package 10 and the package insertion hole 24 is relatively narrow, but the first portion where the gap widens. Less likely to occur after 24a. For this reason, the suction due to the capillary action stops at the second portion 24 b and hardly reaches the other portion of the package insertion hole 24. Accordingly, since the arrangement of the ultraviolet curable resin 31 and the thermosetting resin 32 is made uniform in the gap between the package 10 and the package insertion hole 24, the optical axis shift between the package 10 and the sleeve 20 as described above is effective. Can be reduced.

  Moreover, in the conventional optical module, the placement of the adhesive may be biased before the thermosetting resin 32 is cured during the main fixing. Such a deviation in the arrangement of the thermosetting resin 32 also causes a shift in the optical axis between the package 10 and the sleeve 20. On the other hand, in the optical module 1A of the present embodiment and the manufacturing method thereof, the thixo value of the thermosetting resin 32 is 1.6 or more and 3.0 or less. As will be described in detail below, the inventor can reduce the uneven placement of the thermosetting resin 32 when the thixo value of the thermosetting resin 32 is within such a range, and the package 10 and the sleeve 20 can be reduced. It has been found that the optical loss between the semiconductor optical device 40 and the optical fiber 50 due to the deviation of the optical axis from the optical fiber is reduced. That is, according to the optical module 1A of the present embodiment and the manufacturing method thereof, the deviation between the optical axis of the package 10 and the optical axis of the sleeve 20 can be further effectively reduced.

なお、チクソ値は、回転粘度計により測定された粘度から求めた。具体的には、２５℃・２．５回転における粘度を、２５℃・２０回転における粘度で除算した値である。 Table 1 below shows the thixo value of the thermosetting resin 32, the ease of application (the shorter the time for the resin to reach the gap between the package 10 and the package insertion hole 24, the better), the first and the first in the package insertion hole 24. 2 is a table showing the results of examining the presence / absence of two portions 24a and 24b and the optical loss between the semiconductor optical device 40 and the optical fiber 50;

The thixo value was determined from the viscosity measured with a rotational viscometer. Specifically, it is a value obtained by dividing the viscosity at 25 ° C./2.5 revolutions by the viscosity at 25 ° C./20 revolutions.

  As apparent from Table 1, when the thixo value of the thermosetting resin 32 is less than 1.6 (Comparative Example 1), the shape stability after application of the thermosetting resin 32 is impaired. Due to the surface tension (capillary phenomenon) of the resin 32, the resin 32 excessively penetrates into the package insertion hole 24. On the other hand, a complicated recess or the like may be formed inside the package insertion hole 24, and such an internal shape is not always axially symmetric. Therefore, when the thermosetting resin 32 excessively penetrates deep into the package insertion hole 24, the arrangement of the thermosetting resin 32 is biased, and as a result, the optical coupling efficiency between the semiconductor optical device 40 and the optical fiber 50 is increased. descend. On the other hand, if the thixo value of the thermosetting resin 32 is 1.6 or more (Examples 1 to 3), excessive intrusion into the package insertion hole 24 is suppressed, and such an uneven arrangement is reduced. The Therefore, the optical loss between the semiconductor optical device 40 and the optical fiber 50 can be effectively suppressed.

  Further, when the thixo value of the thermosetting resin 32 is larger than 3.0 (Comparative Example 2), the fluidity of the thermosetting resin 32 is low, so that it is difficult to reach the gap between the package 10 and the package insertion hole 24. Ease is reduced. On the other hand, if the thixo value of the thermosetting resin 32 is 3.0 or less (Examples 1 to 3), the thermosetting resin 32 efficiently spreads in the gap between the package 10 and the package insertion hole 24 and is applied. The ease can be increased.

  Referring to Table 1, when the first and second portions 24a and 24b are not formed in the package insertion hole 24 (Comparative Example 3), that is, when there is no step inside the package insertion hole 24, Even if the thixo value of the thermosetting resin 32 is 3.0, the optical loss between the semiconductor optical device 40 and the optical fiber 50 is relatively high. On the other hand, even if the thixo value is the same, when the first and second portions 24a and 24b are formed in the package insertion hole 24 (Example 2), the semiconductor optical device 40 and the optical fiber 50 The optical loss during is reduced. From this, it can be seen that the effects of the first and second portions 24a and 24b described above are also obtained in this embodiment.

(Modification)
FIG. 8 is a perspective view showing an appearance of a sleeve 27 according to a modification of the embodiment. The difference between the above embodiment and this modification is the presence or absence of a window in the sleeve. As shown in FIG. 8, the sleeve 27 of this embodiment has a plurality of window portions 28 on the side surface of the package fixing portion 22. The plurality of window portions 28 are openings formed in the side wall of the package insertion hole 24, and the planar shape thereof is, for example, a quadrangle. The plurality of window portions 28 are formed at equal intervals in the circumferential direction of the package insertion hole 24 (that is, the direction around the optical axis of the package 10). The other shape of the sleeve 27 is the same as that of the sleeve 20 of the above embodiment.

  These window portions 28 are used when the ultraviolet curable resin 31 is cured by irradiating ultraviolet rays. That is, when the ultraviolet curable resin 31 is cured, the ultraviolet light also enters from the window portion 28, and the ultraviolet curable resin 31 applied to the inside of the package insertion hole 24 can be cured more efficiently. The optical module 1 </ b> A according to the above embodiment may include the sleeve 27 having such a shape instead of the sleeve 20.

  The preferred embodiments of the optical module and the method for manufacturing the optical module according to the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1A ... Optical module, 10 ... Package, 11 ... Lead frame, 12 ... Ball lens, 13 ... Resin lens, 20 ... Sleeve, 21 ... Optical fiber fixing part, 22 ... Package fixing part, 23 ... Optical fiber insertion hole, 24 ... Package insertion hole, 24a ... 1st part, 24b ... 2nd part, 25 ... Through-hole, 26 ... Slit, 27 ... Sleeve, 28 ... Window part, 31 ... UV curable resin, 32 ... Thermosetting resin, DESCRIPTION OF SYMBOLS 40 ... Semiconductor optical element, 41 ... Submount, 50 ... Optical fiber, 51 ... Ferrule, 60 ... Molding die, 62 ... Lower die, 63 ... Upper die, A ... Predetermined direction.

Claims (4)

An optical module for optically coupling a semiconductor optical device and an optical fiber,
A package including a columnar portion including the semiconductor optical element and a lens optically coupled to the semiconductor optical element;
It has a cylindrical shape extending in a predetermined direction, an optical fiber insertion hole for receiving the end of the optical fiber is formed on one end side in the predetermined direction, and the end of the optical fiber and the semiconductor optical element are the lens A package insertion hole for receiving the cylindrical portion of the package so as to be optically coupled to each other via a sleeve formed on the other end side in the predetermined direction,
The package insertion hole is located on the other end side in the predetermined direction with respect to the first portion, a first portion facing the columnar portion and having a first inner diameter, and the columnar portion And a second portion having a second inner diameter that is smaller than the first inner diameter,
The sleeve has a plurality of slits formed side by side in the circumferential direction of the package insertion hole,
An ultraviolet curable resin disposed in a gap between the second portion and the columnar portion to bond the sleeve and the package to each other, and a gap between the peripheral edge portions of the plurality of slits and the columnar portion. A thermosetting resin that adheres the sleeve and the package to each other;
An optical module, wherein the thermosetting resin has a thixo value of 1.6 or more and 3.0 or less.   The optical module according to claim 1, wherein the package is formed by molding using a translucent resin. An optical module manufacturing method for optically coupling a semiconductor optical device and an optical fiber,
The columnar portion of the package including the semiconductor optical element and a lens optically coupled to the semiconductor optical element and having a columnar portion has a cylindrical shape extending in a predetermined direction, and an end of the optical fiber The cylindrical portion of the package is formed so that an optical fiber insertion hole is formed on one end side in the predetermined direction, and the end portion of the optical fiber and the semiconductor optical element are optically coupled to each other through the lens. A package insertion hole for receiving the tape is inserted into the package insertion hole of the sleeve formed on the other end side in the predetermined direction, and the bonding step of bonding the package and the sleeve,
The package insertion hole is located on the other end side in the predetermined direction with respect to the first portion, a first portion facing the columnar portion and having a first inner diameter, and the columnar portion And a second portion having a second inner diameter that is smaller than the first inner diameter,
The sleeve has a plurality of slits formed side by side in the circumferential direction of the package insertion hole,
The bonding step includes a first step in which an ultraviolet curable resin is disposed in a gap between the second portion and the columnar portion to bond the sleeve and the package to each other, and a heat treatment after the first step. A second step of disposing a curable resin in a gap between a peripheral portion of the plurality of slits and the cylindrical portion and bonding the sleeve and the package to each other;
The method for producing an optical module, wherein the thermosetting resin has a thixo value of 1.6 or more and 3.0 or less.   The method for manufacturing an optical module according to claim 3, wherein the preparing step includes a step of forming the package by molding using a light-transmitting resin.

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