WO2006137451A1

WO2006137451A1 - Optical component

Info

Publication number: WO2006137451A1
Application number: PCT/JP2006/312438
Authority: WO
Inventors: Atsushi Aratake; Motohaya Ishii; Yasuyuki Inoue; Tomohiro Nakanishi; Satoru Konno; Shinichi Tsuda; Fumiaki Hanawa; Tomoyo Shibazaki
Original assignee: Nippon Telegraph And Telephone Corporation; Ntt Electronics Corporation
Priority date: 2005-06-21
Filing date: 2006-06-21
Publication date: 2006-12-28
Also published as: JP4663716B2; JPWO2006137451A1

Abstract

This invention provides an optical component that can prevent destructive separation of a part bonded with an adhesive and is more reliable. The optical component comprises an optical fiber held and fixed, with an adhesive, between a substrate and a lid. In this case, the adhesive strength of the adhesive is unevenly distributed to relax the internal stress in the curing. Thus, a site having low adhesive strength is intentionally provided, and, upon the occurrence of internal stress, this site is partially separated. According to this constitution, the stress is absorbed or relaxed, and destructive separation of the substrate and lid by external stress such as a temperature change or a humidity change can be prevented. The uneven adhesive strength can be realized by adding an additive to the adhesive, by chemically treating the bonded face between the substrate or the lid and the adhesive, or by physical processing.

Description

Specification

Optical parts

Technical field

The present invention relates to an optical component in which an optical fiber between a substrate and a lid is fixed with an adhesive.

Background art

[0002] Optical fiber-based optical communication technology supports the increase in communication traffic accompanying the explosive spread of the Internet. In particular, with the recent progress of broadband network, music and video transmission and real-time communication using FTTH access network has been realized.

[0003] Communication using such an optical fiber requires an interface for connecting the optical fiber and the optical device. Normally, optical fibers are handled in the form of tape fibers covered in parallel if there are multiple fibers, and the optical fibers are placed on a substrate with V-grooves and fixed with a lid to connect the fibers to the device. Optical components such as optical fiber arrays are used. This optical fiber array requires precise optical alignment with an optical device such as a planar optical circuit (PLC), and its connection must be strong enough to withstand use.

FIG. 36 shows an example of such an optical component. As shown in FIG. 36, the optical component 100 has a structure in which the optical fiber 2 or the optical fiber array 3 is connected to the PLC 1 using the V-groove substrate 20 and the lid 10. In this case, the optical fiber or the optical fiber array is sandwiched between the V-groove substrate and the lid and fixed with an adhesive. FIG. 37 is a side view showing another example of such an optical component. As shown in the figure, the optical component 200 may have a structure in which the optical fiber 2 is connected to the PLC 1 using a silicon bench 20 and a lid 10 in which V grooves are formed. In this case as well, the optical fiber is sandwiched between the silicon bench and the lid and fixed with an adhesive. A conventional structure of such an optical component is described in Patent Document 1, for example.

However, in the conventional structure, peeling may occur between the lid and the optical fiber, between the optical fiber and the substrate, and between the lid and the substrate due to external factors such as temperature change and humidity change. is there . This delamination caused positional shift and delamination at the connection between the optical fiber and the optical device, and in some cases caused an optical disconnection, which was a cause of damaging the optical characteristics. [0006] When an optical component such as this is actually subjected to a reliability test, particularly an accelerated test under high temperature and high humidity, a delamination phenomenon appears prominently, not only at the interface between the adherend and the adhesive, Cohesive failure and mixed failure that occur simultaneously occur.

[0007] In addition, there is a known method for strengthening the adhesive strength at the roughened adhesive surface by roughening the adhesive surface of the substrate, such that the lid does not peel off the substrate! (Patent Document 2). However, if the bonding surface of the substrate is further reduced due to a demand for downsizing of optical components, sufficient bonding strength may not be obtained between the substrate and the lid even if the bonding surface is roughened. . Further, in the highly integrated and high-density optical component, there has been a problem that the mechanical strength of the substrate and the lid is lowered due to scratches or lacks in dicing during manufacturing.

Patent Document 1: Japanese Patent Laid-Open No. 7-209547

Patent Document 2: Japanese Patent Laid-Open No. 11 142673

Disclosure of the invention

[0009] The present invention has been made in view of such problems, and an object of the present invention is to provide a more reliable optical component by preventing destructive peeling of an adhesive portion by an adhesive. There is.

In order to achieve the above object, according to an embodiment of the present invention, in an optical component in which an optical fiber is sandwiched between a substrate and a lid and fixed with an adhesive, the bonding is performed. The adhesive strength of the adhesive is unevenly distributed, thereby reducing the internal stress of the adhesive due to external stress.

[0011] Further, according to one embodiment of the present invention, in the above optical component, the adhesive force of the adhesive can be made non-uniform by adding an additive to the adhesive.

[0012] According to one embodiment of the present invention, in the above optical component, the adhesive force of the adhesive is made non-uniform by attaching an organic substance or an inorganic substance to at least one of the bonding surfaces of the substrate and the lid. be able to.

[0013] Further, according to one embodiment of the present invention, in the optical component described above, the adhesive force of the adhesive is not uniform by modifying the adhesion surface of at least one of the substrate and the lid by surface treatment. Can be.

[0014] Further, according to an embodiment of the present invention, in the above optical component, the adhesive strength of the adhesive is In addition, it is possible to make the surface uneven by providing irregularities on the bonding surface of at least one of the substrate and the lid.

[0015] Further, according to one embodiment of the present invention, in the above optical component, the adhesive force of the adhesive may be made uneven by roughening at least one of the adhesion surfaces of the substrate and the lid. it can.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a state in which an adhesive containing a normal amount of a silane coupling agent is filled between a V-groove substrate and a lid.

FIG. 2 is a cross-sectional view showing a state where an adhesive to which a silane coupling agent less than a normal amount is added is filled between the V-groove substrate and the lid.

[FIG. 3] FIG. 3 is a cross-sectional view showing a state in which an adhesive to which a larger amount of a silane coupling agent is added than a normal amount is filled between the V-groove substrate and the lid.

FIG. 4A is a perspective view showing a state in which a silane coupling agent is applied in a circular pattern to the adhesion surface of a V-groove substrate.

FIG. 4B is a perspective view showing a state in which a silane coupling agent is applied in a circular pattern on the adhesive surface of the lid.

FIG. 5 is a cross-sectional view showing a state where an optical fiber is fixed between the V-groove substrate of FIG. 4A and the lid of FIG. 4B and is filled with an adhesive.

[FIG. 6A] FIG. 6A is a diagram showing a step of applying a photosensitive resin when a photosensitive resin is produced with a desired pattern on an adhesive surface.

[FIG. 6B] FIG. 6B is a diagram showing a process of exposing with a mask when a photosensitive resin is formed on the adhesive surface in a desired pattern.

[FIG. 6C] FIG. 6C is a diagram showing a process of developing a pattern when a photosensitive resin is produced with a desired pattern on an adhesive surface.

[FIG. 7A] FIG. 7A is a diagram showing a process of applying a resist when performing plasma treatment on a bonding surface with a desired pattern.

[FIG. 7B] FIG. 7B is a diagram showing a step of exposing with a mask when performing plasma treatment on a bonding surface with a desired pattern. [FIG. 7C] FIG. 7C is a diagram showing a process of developing a pattern when the adhesive surface is subjected to plasma treatment with a desired pattern.

[FIG. 7D] FIG. 7D is a diagram showing a step of performing a plasma treatment when performing a plasma treatment on a bonding surface with a desired pattern.

[FIG. 7E] FIG. 7E is a diagram showing a step of removing the resist when the adhesive surface is subjected to plasma treatment with a desired pattern.

[FIG. 8A] FIG. 8A is a diagram showing a process of applying a resist when forming irregularities on a bonding surface with a desired pattern.

[FIG. 8B] FIG. 8B is a diagram showing a process of exposing with a mask when irregularities are formed in a desired pattern on an adhesive surface.

[8C] FIG. 8C is a diagram showing a process of developing the pattern when the unevenness is formed with a desired pattern on the bonding surface.

FIG. 8D is a diagram showing a process of performing ion milling when forming irregularities with a desired pattern on the bonding surface.

[FIG. 8E] FIG. 8E is a diagram showing a step of removing the resist when forming irregularities with a desired pattern on the bonding surface.

[FIG. 9A] FIG. 9A is a plan view showing irregularities of a grid pattern formed on the bonding surface of the lid.

[9B] FIG. 9B is a plan view showing the unevenness of the grid pattern formed on the adhesion surface of the V-groove substrate.

[FIG. 10A] FIG. 10A is a plan view showing irregularities of a lattice point pattern formed on the bonding surface of the lid.

[10B] FIG. 10B is a plan view showing the unevenness of the lattice point pattern formed on the bonding surface of the V-groove substrate.

[11] FIG. 11 is a graph showing the relationship between the bonding strength of the substrate and the lid after the high-temperature and high-humidity test with respect to the depth of the concave and convex portions formed on the bonding surface of the V-groove substrate and the lid.

[FIG. 12] FIG. 12 is a cross-sectional view showing a state where an optical fiber array is fixed and an adhesive is filled between a V-groove substrate having an uneven surface and a lid. [FIG. 13] FIG. 13 is a cross-sectional view showing a state in which an optical fiber array is fixed and an adhesive is filled between a V-groove substrate having a concave and convex portion other than the adhesive surface in contact with the optical fiber array and the lid. It is.

FIG. 14 is a cross-sectional view showing a process of forming fine grooves on the bonding surface of the V-groove substrate or the lid with a dicing saw.

FIG. 15A is a plan view showing a lid in which fine grooves are formed on the bonding surface with a dicing saw.

FIG. 15B is a plan view showing a V-groove substrate in which fine grooves are formed on the bonding surface with a dicing saw.

FIG. 16A is a plan view showing a lid in which grooves are formed in a plurality of directions on the bonding surface.

FIG. 16B is a plan view showing a V-groove substrate in which grooves are formed in a plurality of directions on the bonding surface.

[17A] FIG. 17A is a diagram showing a process of heating the substrate to soften it and pressing the mold when producing irregularities using the nanoimprint technology.

[17B] FIG. 17B is a diagram showing a process of forming a V-groove and unevenness on the substrate simultaneously by pressing the mold when forming the unevenness using the nanoimprint technology.

FIG. 18 is a cross-sectional view showing a state in which an optical fiber array is fixed and an adhesive is filled between a substrate having a roughened adhesive surface and a lid.

FIG. 19 is a view showing the relationship between the surface roughness Ra and the adhesion strength of the substrate and the lid after the high-temperature and high-humidity test.

[FIG. 20A] FIG. 20A is a plan view showing a lid in which a large number of random thin wires are produced on a bonding surface by a scriber, a diamond cutter or the like.

[FIG. 20B] FIG. 20B is a plan view showing a V-groove substrate in which a large number of random fine wires are produced on a bonding surface by a scriber, a diamond cutter or the like.

FIG. 21A is a plan view showing a lid in which fine wires are randomly formed in a plurality of directions on a bonding surface by a scriber, a diamond cutter, or the like.

FIG. 21B is a plan view showing a V-groove substrate in which fine wires are randomly formed in a plurality of directions on a bonding surface using a scriber, a diamond cutter, or the like. FIG. 22 is a perspective view of an optical component in which a fixing member is bonded to both side surfaces of a substrate and a lid.

FIG. 23 is a perspective view of an optical component in which a fixing member is bonded to one side surface of a substrate and a lid.

FIG. 24 is a perspective view of an optical component in which a fixing member is bonded to one side surface of the substrate and the lid, and the bonding area between the lid on the other side and the substrate is increased.

[FIG. 25] FIG. 25 is a perspective view of an optical component in which a plurality of fixing members are selectively bonded to locations where peeling between the substrate and the lid is likely to occur.

FIG. 26 is a perspective view of an optical component having a fixing member bonded over the entire side surface of the substrate.

FIG. 27 is a perspective view of an optical component in which a semi-cylindrical fixing member is bonded to the side surfaces of a substrate and a lid.

FIG. 28 is a perspective view of an optical component in which a trapezoidal fixing member is bonded to the side surfaces of a substrate and a lid.

FIG. 29 is a perspective view of an optical component in which a U-shaped fixing member is mounted on the side surfaces of the substrate and the lid and the bottom surface of the substrate.

FIG. 30 is a perspective view of an optical component in which a U-shaped fixing member is mounted on a side surface of a substrate and a lid, and an upper surface of the lid.

FIG. 31 is a perspective view of an optical component in which a U-shaped fixing member is attached to a side surface of a substrate, a lid, and an upper surface of the lid so as to cover the fiber core wire.

FIG. 32 is a perspective view of an optical component in which a U-shaped fixing member is attached to one side surface of the substrate and the lid, the bottom surface of the substrate, and the upper surface of the lid.

FIG. 33 is a cross-sectional view of an optical component in which a U-shaped fixing member is attached to one side surface of the substrate and the lid, a part of the bottom surface of the substrate, and a part of the lid.

[FIG. 34] FIG. 34 is a perspective view of an optical component equipped with a square-shaped fixing member so as to cover the substrate, the lid and all four sides.

[FIG. 35A] FIG. 35A is a plan view of an optical component for illustrating the width of a flat portion on the outside of the V-groove on the substrate. FIG. 35B is a cross-sectional view of the tape fiber taken along line XXXVB in FIG. 35A.

FIG. 35C is a cross-sectional view of the substrate and the lid taken along line XXXVC in FIG. 35A.

FIG. 36 is a perspective view showing an example of an optical component.

FIG. 37 is a perspective view showing another example of an optical component.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] In the structure of an optical component in which an optical fiber is sandwiched between a substrate and a lid and fixed with an adhesive, peeling or breakage may occur when a reliability test is performed as described above. However, such a peeling phenomenon does not occur when the flat plate of the substrate and the lid are bonded together with an adhesive. For this reason, the peeling phenomenon between optical component components (substrate, optical fiber, lid) is not simply caused by the weak adhesive force of their bonding surfaces, but the inherent stress generated when the adhesive cures and shrinks. It seems to be deeply related. That is, when the adhesive is cured, the distance between the substrate and the lid is almost the same as the distance between the substrate and the lid because the optical fiber becomes a spacer, even though the adhesive resin shrinks. It is considered that peeling occurs due to the concentration of the internal stress of the adhesive near the outer periphery of the adhesive surface. Due to this peeling, the fiber cannot be gripped or fixed between the substrate and the lid, the fiber is displaced, and the optical characteristics of the optical component are deteriorated.

[0018] In the present invention, a region where the adhesive strength with the adhesive is weak is intentionally formed on the surface where the substrate and the lid are in contact with the adhesive, and when the internal stress is generated, the region is partially peeled off. By doing so, the internal stress is absorbed or relaxed. As a result, the adhesive strength between the substrate and the lid is maintained, and destructive peeling is prevented. In the prior art, not only destructive delamination but also partial delamination has been devised. In contrast, the present invention actively induces partial delamination and prevents the occurrence of destructive delamination between the substrate, the lid and the optical fiber.

[0019] In order to change the adhesive strength of the adhesive, in the present invention, an additive may be added to the adhesive, or a chemical treatment or physical processing may be performed on the bonding surface of the substrate and the lid. it can. Since the purpose is to alleviate the internal stress in the adhesive grease, the adhesive force change pattern must be larger than the polymerized molecules of the adhesive. However, if the adhesive force change pattern is too large, the adhesion area will decrease and all of the substrate, lid and optical fiber will be reduced. Physical bond strength is reduced. For this reason, it is desirable that the actual interval between the change patterns is 0.1 to 100 m.

[0020] When the ratio of the adhesive with respect to the entire area where the adhesive strength is weak is small, the effect of maintaining the adhesive strength is small, and the relaxation effect of the internal stress is small. On the other hand, if the ratio is large, the effective bonding area between the adhesive and the adherend decreases. Therefore, the lowering of the adhesive strength by the adhesive is more problematic than the effect of maintaining the adhesive strength by stress relaxation. Become. For this reason, it is desirable that the actual proportion of the weakly adhesive portion is 5% to 50%.

[0021] This ratio can be confirmed visually with a microscope when the substrate or lid is made of a transparent material such as glass. Specifically, the site where the adhesive strength with the adhesive is weak can be observed as a bubble or a peeled state. However, since it may not appear as a bubble or exfoliation under normal conditions, in such a case, the bubble or exfoliation may become apparent by applying external stress for a short time, such as in an accelerated test at high temperature and high humidity. Can be observed.

[0022] In addition, since stress is concentrated along the optical fiber at the bonded portion of the substrate, the optical fiber, and the lid, it is important to intentionally cause bubbles or peeling at this portion. When the adhesive layer is several meters to several tens / zm, it is empirically desirable that bubbles or delamination be distributed along the fiber in a region within 5 mm of the fiber.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

Example 1

[0024] In the first embodiment of the present invention, by adding an additive in the adhesive, it is possible to create a region where the adhesive strength of the adhesive is not uniform on the contact surface between the substrate and the lid. Specifically, a silane coupling agent can be used as an additive. Silane coupling agents are usually used to improve adhesion. This is because the silane coupling agent is covalently bonded to an inorganic material by hydrogen bonding or dehydration reaction, and the silane coupling agent and the organic material are bonded by hydrogen bonding or intermolecular force, or are covalently bonded by chemical reaction. By doing so, you can obtain a strong bond. Usually, when a silane coupling agent is added to the adhesive, the amount is adjusted so that the silane coupling agent adheres uniformly to the bonding surface of the substrate and the lid. Figure 1 shows this situation. Figure 1 shows the adhesive 30 with the silane coupling agent 40 added to the substrate 20 It shows the state filled with the door 10. Ideally, as shown in FIG. 1, the amount is adjusted so that only one functional silane molecular layer uniformly adheres to the bonding surface of the substrate 20 and the lid 10.

[0025] However, in the present invention, a region where the silane coupling agent does not adhere is created by reducing the addition amount less than the addition amount in which only one molecular layer adheres uniformly. This is shown in Figure 2. FIG. 2 shows a state in which an adhesive 30 prepared by adjusting the silane coupling agent 40 less than usual is filled between the substrate 20 and the lid 10 according to an embodiment of the present invention. By adjusting in this way, the part of the adhesive surface to which the silane coupling agent 40 does not adhere is likely to cause partial peeling with respect to the internal stress where the adhesive force with the adhesive is weak. By making the addition amount 5% to 50% with respect to the ideal addition amount, a stress relaxation effect can be obtained as desired.

[0026] The same effect can be obtained by increasing the amount of the silane coupling agent beyond the ideal addition amount. This is shown in Figure 3. FIG. 3 shows a state where an adhesive 30 in which the amount of the silane coupling agent 40 is adjusted more than usual is filled between the substrate 20 and the lid 10 according to an embodiment of the present invention. . Thus, when the amount of the silane coupling agent is increased, the molecules of the silane coupling agent are bonded to each other. This bond is generally weaker than the bond between adhesive molecules. Therefore, the portion where the molecules of the silane coupling agent are bonded to each other easily causes partial peeling with respect to the internal stress.

[0027] In this example, the same results can be obtained by adding other suitable additives with the force described with the silane coupling agent as an example of the additive. Usually, the additive is used for the purpose of adjusting the viscosity of the adhesive, but in the present invention, it is used to make the adhesive strength of the adhesive non-uniform. Therefore, any additive can be used to achieve this purpose. For example, the ability to use silica, quartz, plastic, wood, metal, graphite, carbon nanotube, etc. Absent.

[0028] The total area of the partial peeling or weak adhesive strength caused by the additive is desirably 5% to 50% of the area of the bonding surface of the substrate or the lid. In addition, it is desirable that the part with weak peel or adhesion strength exists along the fiber at a part within 5mm from the fiber. Example 2

[0029] In the second embodiment of the present invention, a chemical surface treatment is applied to the bonding surface of the substrate and the lid, thereby creating a region where the adhesive strength of the adhesive is not uniform on the bonding surface of the substrate and the lid. be able to. Specifically, a silane coupling agent is applied to the bonding surface between the substrate and the lid by an ink jet method to form a circular pattern with a spacing of 3 / zm. This is shown in Figures 4A and B. 4A and 4B show a state in which the silane coupling agent 42 is applied in a circular pattern on the bonding surfaces of the substrate 20 and the lid 10, respectively. FIG. 5 shows a state in which the optical fiber 2 is mounted in the V-groove 21 between the substrate 20 coated with the silane coupling agent 42 in a circular pattern and the lid 10, and the adhesive 30 is filled. .

[0030] When a silane coupling agent is applied to the surface of a substrate or lid such as glass or silicon and dried, the wettability and compatibility with the adhesive is improved in the portion where the silane coupling agent is applied. Furthermore, the surface and the adhesive bond to each other by a covalent bond or hydrogen bond, thereby forming a strong adhesive surface. On the other hand, the part where the silane coupling agent is not applied is in a state where such a mechanism does not work and peeling is likely to occur. As a result, the part that has not been surface-treated absorbs or relaxes stress that is easily peeled off, and the part that has been surface-treated becomes difficult to peel, resulting in external stress such as high temperature and high humidity. On the other hand, destructive peeling can be prevented, and optical fiber position shift, pitch shift, and disconnection can be effectively prevented.

[0031] It should be noted that the application pattern on the adhesive surface may be an ellipse, a triangle, a polygon, or any indefinite shape, which need not be circular. The size of the pattern can also be selected to give the desired change in adhesive strength. In the above embodiment, the interval for applying the silane coupling agent is 3 μm, but the silane coupling agent is applied! Wow! /, The interval between the parts (the part where the adhesive strength of the adhesive is weakened) is in the range of 0.1 μπι to 100 / ζ m, as described above, and is 1 μm to 10 μm. It is preferable. When this distance is less than 1 μm, the pattern for applying the silane coupling agent becomes fine, which makes it difficult to manufacture. Also, if it exceeds 10 m, sufficient stress relaxation will not be performed in the adhesive layer.

[0032] Further, it is desirable that the total area of the portion to which the silane coupling agent is applied is 5% to 50% of the bonding surface of the lid or the substrate. This uncoated part is applied by subjecting this part to a high temperature and high humidity accelerated test (eg 130 ° C 90% RH) for 1 hour. Peeling occurs in the unexposed part, and the area of the part can be visually evaluated. In addition, it is desirable that the part where peeling or adhesion is weak should be along the fiber within 5mm from the fiber.

[0033] In the above embodiment, the case where a silane coupling agent is used as the coating agent has been described as an example. However, any silazane (for example, hexamethyldisilazane) that can change the adhesive force can be used. Forces that can achieve the same effect even if organic substances (epoxy, acrylic, polyimide, silicone, PMMA, PC, BCB, urethane, etc.) other than the adhesive used for bonding optical fibers are applied. is not. In addition, it is not necessary to improve the adhesive strength like silane coupling agents, but to use a material that lowers the adhesive strength, such as fluorine-containing resin, to make it easier to peel off the applied part. It may be. The material for changing the adhesive force may not be an organic material, but an inorganic material such as a metal, for example, may be deposited and lifted off to form the above pattern on the adhesive surface. For example, when Au is used, the Au surface becomes a weakly adhesive part where the wettability of the adhesive is poor.

[0034] In the above-described embodiment, the force of applying an organic material using an ink jet method generates mist by any method that can apply a desired material, such as spraying, ultrasonic waves, and publishing. A mist spraying method in which the adhesive surface is exposed to a gas in a mist atmosphere and a method in which a photosensitive resin is applied and pattern exposure is performed can be used, but the method is not limited thereto. Figures 6A to C show an example of a process in which a photosensitive resin is applied, patterned and developed. First, as shown in FIG. 6A, a photosensitive resin 50 is applied to the lid 10 (or the substrate 20). Next, as shown in FIG. 6B, the photosensitive resin 50 is exposed using a mask 60 having a desired pattern. Finally, as shown in FIG. 6C, the exposed photosensitive resin 50 is developed to obtain a desired pattern. As a result, the photosensitive resin 50 can be adhered to the lid or the bonding surface of the substrate in a desired pattern.

[0035] Furthermore, in one embodiment of the present invention, the wettability of the adhesive surface can be changed without applying a resin to the adhesive surface, so that, for example, the adhesive surface is plasma-treated with a desired pattern. You may do it. Figures 7A through E show an example of such a plasma treatment. First, as shown in FIG. 7A, a resist 52 is applied to the lid 10 (or the substrate 20). Next, as shown in FIG. 7B, the resist 52 is exposed using a mask 60 having a desired pattern. Next, as shown in Figure 7C As described above, the exposed resist 52 is developed to obtain a desired pattern. Next, as shown in FIG. 7D, the lid 10 having the resist pattern is exposed to plasma. Finally, as shown in FIG. 7E, the resist pattern is removed to obtain a lid 10 having a plasma-treated portion 54. As a result, the wettability of the adhesive 30 is different between the plasma-treated portion 54 and the non-plasma portion, so that the bonding surface can have a non-uniform adhesive force.

Example 3

[0036] In the third embodiment of the present invention, a physical treatment is applied to the bonding surface of the substrate and the lid to create a region where the adhesive strength of the adhesive is not uniform on the bonding surface of the V-groove substrate and the lid. be able to . Specifically, using a wafer-like glass or silicon as a substrate and lid, a resist can be applied, exposed to light, developed, and ion milled to form a physical pattern. Figures 8A through E show an example of such a process. First, as shown in FIG. 8A, a resist 52 is applied to the lid 10 (or the substrate 20). Next, as shown in FIG. 8B, the resist 52 is exposed using a mask 60 having a desired pattern. Next, as shown in FIG. 8C, the exposed resist 52 is developed to obtain a desired pattern. Next, as shown in FIG. 8D, the lid 10 having the resist pattern is etched by Ar ion milling. Finally, as shown in FIG. 8E, the resist pattern is removed, and a lid 10 with unevenness 12 formed by etching is obtained.

[0037] As shown in FIGS. 9A and B, the patterns of the irregularities 12 of the lid 10 and the V-groove substrate 20 are, for example, lattice patterns with an interval of L m, or as shown in FIGS. 1 OA and B, respectively. Or a lattice point pattern. Thereby, since the adhesive force of the adhesive is different between the concave portion and the convex portion, it is possible to give a non-uniform adhesive force to the bonding surface.

FIG. 11 shows the relationship between the lid and the substrate manufactured in this way and the adhesive strength of the substrate and the lid after the high-temperature and high-humidity test with respect to the depth of the recess. From this figure, it can be seen that there is no effect if the depth of the recess is less than 0 .: L m. In addition, if the depth of the recess exceeds 10 m, it becomes difficult to ensure the accuracy of the V-groove and the pitch accuracy of the fiber when the optical fiber is mounted. Therefore, the etching depth is 0.1 π! Desirably ~ 10 m. Further, the etching depth can be adjusted by the thickness of the adhesive layer and the curing shrinkage rate. For example, if the thickness of the adhesive layer is 20 μm, the appropriate etching depth is 0.5 μm to 5 μm. Further, it is desirable to be 1 to 2 / ζ πι.

FIG. 12 shows a cross-sectional view of an optical component in which a fiber array is fixed using the V-groove substrate 20 and the lid 10 having such irregularities. In a recess made by etching or the like, peeling with a high cure shrinkage rate of the adhesive tends to occur. In response to changes in temperature or humidity, this part peels off, reducing the internal stress. As a result, as in the case of the above embodiment, destructive peeling between the V-groove substrate and the lid can be prevented, and the optical fiber can be prevented from being displaced or disconnected. However, after etching, if residues are generated or the surface is roughened to increase the effective bonding area, or if an anchor strength improvement factor occurs due to the anchor effect, etc. This does not necessarily reduce the bond strength, but the shrinkage of cure and their effects may be traded off or reversed.

[0040] The total area of the recesses produced by etching is preferably 5% to 50% of the area of the bonding surface between the substrate and the lid. In the case of a material with poor wettability, these portions are in a state where bubbles remain inside the recess, and a stress relaxation effect is obtained at the time of curing. In addition, when the adhesive penetrates into the inside of the concave part with good wettability, the stress is relaxed by curing and shrinking the adhesive. Needless to say, even if no peeling occurs at the time of curing shrinkage, the same effect can be obtained if peeling occurs at the stage when external stress was strong.

[0041] When holding the optical fiber with the rugged lid 10, if the ridge irregularity 12 is large, proper fixing of the fiber 2 may be hindered. For this reason, as shown in FIG. 13, the bonding surface with which the fiber contacts may not be provided with unevenness.

In the present embodiment, an Ar ion milling method has been described as an etching method. However, the same effect can be obtained even if the etching is performed by wet etching using acid or alkali or reactive ion etching (RIE). In addition to etching, a fine groove may be formed with a dicing saw 70 as shown in FIG. As a result, as shown in FIG. 15A (or FIG. 15B), many thin grooves 13 can be formed on the bonding surface of the lid 10 (or the substrate 20), and the same effect as in the case of etching can be obtained. be able to. As shown in FIGS. 16A and 16B, the groove to be produced can obtain a higher stress relaxation effect by forming the groove 14 in a plurality of directions. In either case, it is desirable to form grooves or irregularities in the direction along the fiber within 5mm of the fiber. [0043] When the V-groove substrate and the lid are heat-processable materials, the unevenness can also be produced using nanoimprint technology. Figures 17A and B show the process of making irregularities using such a technique. As shown in FIG. 17A, the substrate 20 made of a material such as glass or plastic is heated and softened, and the mold 80 is pressed against the substrate. Thus, the desired irregularities 12 are obtained on the bonding surface of the substrate 20 as shown in FIG. 17B. Further, as shown in the figure, if the irregularities 12 are produced in the same process as the production of the V groove 21 of the substrate 20, the number of processes and the production time can be shortened.

[0044] As another embodiment of the present example, the adhesive surface of the substrate and the lid is physically roughened so that the adhesive strength of the adhesive is not uniform on the adhesive surface of the V-groove substrate and the lid. Can be made. Specifically, the adhesive surface of the V-groove substrate and the lid is roughly polished with # 200. FIG. 18 shows a state in which the optical fiber 2 is fixed between the substrate 20 and the lid 10 having a roughened adhesive surface in this manner, and the adhesive 30 is filled. Random depressions 15 as shown in FIG. 18 can change the adhesive force, cause partial peeling, and relax the internal stress due to external stress. In this embodiment, the adhesive surface can be characterized by the surface roughness Ra defined by JIS, not by the pattern interval and the etching amount described above. By performing rough polishing so that the surface roughness Ra is 1 to 5 m, an appropriate stress relaxation effect can be obtained, and further, rough polishing is performed so that the surface roughness is 1 to 2 m. Is desirable.

FIG. 19 shows the relationship between the surface roughness Ra and the adhesive strength between the substrate and the lid after the high temperature and high humidity test. As shown in FIG. 19, sufficient adhesion strength is maintained in the region where the surface roughness Ra exceeds: L m. However, if the surface roughness Ra exceeds 5 m, stable fixing of the optical fiber will be hindered, which may result in misalignment or pitch displacement. Therefore, the range of the surface roughness Ra is suitably 1 μm to 5 μm.

[0046] It should be noted here that it is important to create a recess that weakens the adhesive force between the V-groove substrate or the lid and the adhesive, and this recess portion causes stress relaxation of the adhesive, The overall adhesive strength is maintained against external stress. Therefore, the effect is not obtained on any surface as long as the surface roughness Ra is in the range of 1 μm to 5 μm. For example, on a surface where protrusions with a height of 10 μm are arranged at intervals of 10 μm and the other part is flat, the direction of adhesion strength is increased due to the anchor effect and increased adhesion area. Although the above can be obtained, it is difficult to generate a portion having a low adhesive strength, so that the relaxation effect of the internal stress of the adhesive is low enough to maintain the adhesive strength against a low external stress.

[0047] For this reason, instead of the depth of the recess used in FIG. 11, the adhesion surface may be characterized by a ten-point average roughness Rz defined by JIS. The ten-point average roughness Rz is preferably 0.25≤Rz / t≤2.5, where t is the thickness of the adhesive layer between the substrate and the lid. When t is 20 μm, the ten-point average roughness Rz is 5 μm to 50 μm. In this case, if the 10-point average roughness Rz is less than, the stress relaxation effect is difficult to prevent partial peeling at the recesses. In addition, if Rz exceeds 50 μm, positional deviation and pitch deviation are likely to occur when optical fibers are mounted. If the position or pitch of the optical fiber becomes a problem due to unevenness on the surface, do not perform rough polishing on the surface of the lid in contact with the optical fiber.

[0048] As a method for roughening the bonding surface, the substrate or the lid may be directly rough-polished, or may be mirror-polished and then roughened by blasting or the like. In addition, as shown in FIGS. 20A and 20B, the same effect can be obtained even if a large number of random thin wires 16 are formed on the adhesion surface of the V-groove substrate 20 and the lid 10 by a scriber or a diamond cutter that is not polished. It is In addition, as shown in FIGS. 21A and 21B, thin wires 17 may be randomly formed on the bonding surface in a plurality of directions.

[0049] Even in the case of misalignment, the total area of the substrate having a roughened adhesive surface and the weakly adhesive portion between the lid adhesive and the adhesive area between the substrate and the lid is 5% to 50%. Is desirable. The weak adhesive strength !, the part can be visually observed as partial peeling or bubbles when the adhesive is cured. If it does not appear as peeling or bubbles, it can be exposed to an external stress such as a high-temperature and high-humidity test for a short time to reveal the peeling or bubbles and visually check them. In addition, it is desirable that such weakly bonded parts exist along the fiber within a distance of 5 mm from the fino.

[0050] When the optical fiber array mounting component according to each of the above-described embodiments was manufactured and subjected to an accelerated test at high temperature and high humidity, the delamination of the bonded portion was less than that of the conventional optical fiber array mounting component. It was suppressed and it was confirmed that high adhesive strength can be maintained. Further, when an optical device using the optical fiber array mounting component of the present invention was subjected to a high temperature and high humidity acceleration test, Higher reliability was obtained than before, and the effectiveness of the present invention was confirmed.

Example 4

[0051] As miniaturization of optical components progresses, the area of the bonding surface of the substrate having the V-groove decreases, and the adhesive force with the lid decreases. Also, in the manufacture of small optical components, processing such as dicing causes scratches and chips on the substrate and lid of the optical component, and the mechanical strength of the optical component is reduced. Therefore, in the fourth embodiment of the present invention, by supporting the substrate and the lid with a fixing member, the adhesive strength between the substrate holding the optical fiber and the lid is enhanced, and the mechanical strength of the optical component is reinforced. can do.

FIG. 22 shows the structure of an optical component according to the fourth embodiment of the present invention. This optical component includes a substrate 20 having a V-groove, an optical fiber array 3 in which a core wire is arranged in the V-groove, a lid 10 mounted on the substrate so that the core wire is fixed to the V-groove, and the substrate and the lid. And fixing members 90 bonded to both side surfaces. By adhering the fixing member, the adhesive strength between the V-groove substrate and the lid can be increased. Further, the mechanical strength of the optical component can be reinforced by supporting the side surfaces of the substrate and the lid with fixing members. Here, the V-groove has been described as an example of the groove. However, the shape of the groove that can be a U-shaped groove or a U-shaped groove is not limited as long as the fiber can be accurately fixed.

In FIG. 22, the fixing member 90 is bonded to both sides of the substrate and the lid. However, when sufficient strength is obtained, the fixing member 90 is bonded only to one side as shown in FIG. May be. In this case, the optical component can be further downsized.

[0054] If there is a difference in adhesive strength between the right and left of the lid, as shown in FIG. 24, the fixing member is not bonded to the side to which the fixing member 90 is bonded, and the substrate and the lid on the side are not bonded. The area of the bonding surface of may be increased. By adjusting in this way, the right and left adhesive strength can be balanced.

[0055] Further, the peeling of the lid due to external stress is likely to occur at the end of the lid on the tape fiber side or the opposite end. Therefore, as shown in FIG. 25, a plurality of fixing members 91 may be selectively disposed at a place where peeling is likely to occur.

[0056] Further, it is common to apply a fiber protective agent to the core portion of the fiber. Therefore, as shown in Figure 26, it adheres to both the lid and the board, and further to the entire side of the board. By adhering the fixing member 92, the protective agent can be prevented from flowing out.

The above embodiment relates to a plate-like fixing member, but it can be formed in an arbitrary shape according to the shape of the optical component package. For example, when the optical component package is cylindrical, a semi-columnar fixing member 93 can be used as shown in FIG. Similarly, in the case where it is mounted obliquely in the knocker, a trapezoidal fixing member 94 can be used as shown in FIG. As described above, the shape of the fixing member can be arbitrarily changed depending on the form of the knock box and the mounting method.

Further, instead of using separate fixing members on both sides of the substrate and the lid, as shown in FIG. 29, for example, a U-shaped integral fixing member 95 can be used. This can reduce the number of components on the mounting. In this case, the fixing member 95 may be attached from the substrate side as shown in FIG. 29, or the fixing member 95 may be attached from the lid side as shown in FIG. In particular, when it is necessary to protect the fiber, it is preferable to use a fixing member 96 that is attached from the lid side and covers the fiber core as shown in FIG.

Furthermore, as shown in FIG. 32, a fixing member 97 shaped to cover three sides of the side surface of the optical component, the lower surface of the substrate, and the upper surface of the lid may be used. In this case, it is possible to mechanically reinforce the peeling of the lid. Here, as shown in FIG. 33, it is not necessary that the U-shaped fixing member is in direct contact with the lid and the V-groove substrate. For example, an adhesive 30 can be filled in this gap. Also, as shown in FIG. 33, the U-shaped fixing member covers the entire upper surface of the lid and the entire bottom surface of the board! Good.

[0060] The U-shaped fixing member as shown in FIG. 29 to FIG. 33 can be produced by, for example, cutting out a member such as glass or silicon, but using plastic or metal, etc. It is easier to produce by. In the above embodiment, the U-shaped fixing member has been described as an example. However, the shape is not limited to the U-shape as long as the fiber array component is fixed to the three-way force. .

Further, as shown in FIG. 34, a square shape 98 can be formed so as to cover all four surfaces of the substrate and the lid. As a result, the effects described with reference to FIGS. 29 to 33 can be obtained at once. be able to.

In the above embodiment, by reinforcing the substrate and the lid with the fixing member, it is possible to provide a smaller optical component while maintaining the adhesive strength between the substrate and the lid. However, when tape fiber is used for the optical component, the width of the optical component may be smaller than the width of the tape fiber. This is not a problem when assembling optical components one by one, but multiple tape fibers are mounted on a substrate on which multiple V-groove groups are fabricated, and multiple optical components are gathered together and threaded up. Then, when cutting by dicing or the like, there may be a problem in the dicing process.

FIG. 35A shows a top view of the fiber array optical component, FIG. 35B shows a cross-sectional view of the tape fiber along line XXXVB, and FIG. 35C shows a cross-sectional view of the substrate and lid portions along line XXXVC. As shown in the figure, the width x (Figure 35C) of the flat part outside the V-groove on the substrate must be larger than the tape fiber coating thickness d (Figure 35B), and more than 2d It is desirable that In addition, if x≤W with respect to the width W of the V-grooved part of the V-groove substrate (Fig. 35C), sufficient adhesive strength can be obtained without using a fixing member.

[0064] In the above embodiment, in order to provide the optical component including the fixing member with temperature resistance, the fixing member has the same thermal expansion coefficient as that of at least one of the substrate and the lid, or the same material. It is preferable that For example, if the V-groove substrate is silicon and Ridska s quartz glass, the fixing member is preferably made of silicon or quartz glass.

[0065] When fixing the fixing member to the optical component with an adhesive, it is preferable to use the same adhesive as that used for bonding the substrate and the lid from the viewpoint of reliability. When the same adhesive is used, there is an advantage that when the optical component is assembled, the fixing member can be bonded at the same time in the bonding process of the substrate and the lid.

[0066] Further, when at least one of the bonding surfaces of the fixing member and the substrate and the lid is roughened, the bonding area can be substantially increased, and a higher bonding effect can be obtained. Roughening is more effective when the surface roughness Ra is from 50 nm to 10 μm.

[0067] As the material of the fixing member, glass, silicon, plastic, metal, or the like can be used according to the optical component to be reinforced. In addition, at least one of the board, lid and fixing member When a material having V permeability is used, UV curing resin can be used at the time of assembly, and the assembly process time can be shortened.

[0068] Based on the above-described example, a fiber array optical component smaller than the conventional one was manufactured, and an acceleration test was performed at a high temperature and high humidity. As a result, the same reliability as the conventional one could be secured. By adopting the structure of the optical component according to the present embodiment, it is possible to reduce the size of the optical component while ensuring the reliability of the connection portion with the optical fiber.

[0069] Although several embodiments of the present invention have been specifically described above, in view of many possible embodiments to which the principles of the present invention can be applied, the embodiments described herein are merely examples. However, it is not intended to limit the scope of the present invention. Embodiments exemplified herein can be modified in configuration and details without departing from the spirit of the present invention. Further, the illustrative components and procedures may be changed, supplemented, or changed in order without departing from the spirit of the invention.

Claims

The scope of the claims

[1] In an optical component in which an optical fiber is sandwiched between a substrate and a lid and fixed with an adhesive,

An optical component characterized in that the adhesive force of the adhesive is unevenly distributed, whereby internal stress of the adhesive due to external stress is relieved.

[2] In the optical component according to claim 1,

The optical component according to claim 1, wherein the adhesive strength of the adhesive is unevenly distributed due to partial peeling or bubbles of the adhesive.

[3] The optical component according to claim 1,

An optical component characterized in that the adhesive force of the adhesive is unevenly distributed within 5 mm from the optical fiber.

[4] In the optical component according to claim 1,

The optical component according to claim 1, wherein the adhesive strength of the adhesive is unevenly distributed on or near the adhesion surface of at least one of the substrate and the lid.

[5] The optical component according to claim 4,

An optical component characterized in that the area of the weak adhesive strength of the adhesive is 5% to 50% of the total area of the adhesive surface.

[6] In the optical component according to claim 4,

The optical component is characterized in that the adhesive force of the adhesive is periodically and unevenly distributed.

[7] The optical component according to claim 6,

The optical component characterized in that the periodic change of the adhesive force of the adhesive is 0.1 μm to 100 m.

[8] The optical component according to claim 1,

An optical component characterized in that the adhesive force of the adhesive is made non-uniform by adding an additive to the adhesive.

[9] The optical component according to claim 1,

The optical part is characterized in that the adhesive force of the adhesive is made nonuniform by attaching an organic or inorganic substance to at least one of the adhesive surfaces of the substrate and the lid. Po

[10] The optical component according to claim 9,

The optical component is a silane coupling agent or a fluorine-containing resin.

[11] In the optical component according to claim 9,

The optical component, wherein the inorganic substance is a metal.

[12] The optical component according to claim 1,

The optical component according to claim 1, wherein the adhesive force of the adhesive is made non-uniform by modifying a bonding surface of at least one of the substrate and the lid by a surface treatment.

[13] In the optical component according to claim 1,

The optical component according to claim 1, wherein the adhesive force of the adhesive is made uneven by providing a concave / convex portion on at least one of the adhesive surfaces of the substrate and the lid.

[14] The optical component according to claim 13,

The depth of the unevenness is 0.1 m to 10 m.

[15] In the optical component according to claim 13,

The depth d of the unevenness and the thickness t of the adhesive layer are 0.01 ≦ d / t ≦ 0.2.

[16] The optical component according to claim 1,

The optical component according to claim 1, wherein the adhesive force of the adhesive is made non-uniform by roughening at least one adhesive surface of the substrate and the lid.

[17] In the optical component according to claim 16,

A surface roughness Ra of the roughened adhesive surface is 1 μm to 5 μm.

[18] In the optical component according to claim 16,

The optical component according to claim 10, wherein the ten-point average roughness Rz of the roughened adhesive surface and the thickness t of the adhesive layer are 0.25≤Rz / t≤2.5.

[19] In the optical component according to claim 1,

At least one of the substrate and the lid is made of glass, silicon or plastic An optical component characterized by

[20] In the optical component according to claim 1,

An optical component comprising: a fixing member bonded to at least one of the substrate and the side surface of the lid.

[21] The optical component according to claim 1,

An optical component, wherein a fixing member is mounted so as to cover three surfaces including at least one of the substrate and the side surface of the lid.

[22] The optical component according to claim 20,

The optical component, wherein the fixing member is a flat plate.

[23] In the optical component according to claim 20 or 21,

The width X of the bonding surface between the substrate and the lid is d≤x≤W where d is the coating thickness of the optical fiber and W is the width of the groove portion of the substrate. Optical parts.

[24] In the optical component according to claim 20 or 21,

The optical component according to claim 1, wherein a thermal expansion coefficient of the fixing member is the same as that of one of the substrate and the lid.

[25] The optical component according to claim 20 or 21,

The material of the fixing member is the same as that of either the substrate or the lid.

[26] In the optical component according to claim 20 or 21,

The optical component, wherein the fixing member, the substrate, and the lid are bonded with an adhesive, and the adhesive is the same as the adhesive between the substrate and the lid.

[27] In the optical component according to claim 20 or 21,

The optical component, wherein the fixing member, the substrate, and the lid are bonded with an adhesive, and at least one of the bonding surfaces is roughened.

[28] In the optical component according to claim 20 or 21,

The optical component, wherein the fixing member is glass, silicon, plastic, or metal.

[29] In the optical component according to claim 20 or 21, An optical component, wherein an ultraviolet curable adhesive is used for an adhesive surface between the fixing member, the substrate, and the lid, and at least one of the adhesive surfaces has ultraviolet transparency.