JP2008224938A - Optical control component and manufacturing method of optical control component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical control component having a high reliability of signal propagation, and a manufacturing method of the same. <P>SOLUTION: The optical control component includes an optical waveguide, an electro-optical element installed in the optical waveguide, and an adhesive connecting the optical waveguide and the electro-optical element together. The adhesive is obtained by hardening a material containing a curable resin material and an organic material which has practically the same main molecular as the curable resin material and suppresses hardening contraction of the curable resin material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light control component formed using an electro-optic element and a method for manufacturing the same.

  Along with the increase in the speed of semiconductor devices and electronic equipment, a signal propagation method using an optical waveguide has become widespread as a technique that replaces the conventional electric wiring. For example, the optical waveguide is composed of a so-called core material called a core material that transmits signal light, and a so-called clad material formed so as to cover the periphery of the core material. Since the clad material has a reflectivity different from that of the core material, the signal light directed from the core material to the clad material is substantially totally reflected by the clad material to the core material side.

For example, in signal propagation using the above light, a light control component typified by an optical switch is used. In the above optical switch, for example, signals are switched by an element having an electro-optic effect (electro-optic element). The electro-optic element and the optical waveguide are aligned on the substrate with submicron order accuracy. In addition, since a micron-order gap is formed between the electro-optic element and the optical waveguide (between the electro-optic element and the substrate), the gap is generally filled with an adhesive or the like. For example, a curable resin material that causes a curing reaction by the action of heat or ultraviolet rays is used as the adhesive.
WO 03/104868

  However, if the above-mentioned adhesive is cured after the alignment between the electro-optic element and the optical waveguide in the sub-micron order, the position of the electro-optic element with respect to the optical waveguide may be shifted due to curing shrinkage of the adhesive. there were. As a method for suppressing the curing shrinkage, a method of filling an inorganic powder such as silica or carbon powder in an adhesive may be used.

  However, in the case of an optical switch, light, which is a medium that propagates a signal, may pass through the adhesive due to its structure. For this reason, when an inorganic powder is added to the adhesive, there is a concern that the light amount may be attenuated due to light scattering or the optical path may be abnormally refracted to reduce the reliability of the optical switch. For this reason, it has been substantially difficult to use an adhesive to which an inorganic material is added in a light control component such as an optical switch.

  Therefore, in the present invention, it is a general object to provide a novel and useful light control component and a method for manufacturing the light control component that solve the above-described problems.

  A specific object of the present invention is to provide a light control component with good signal propagation reliability and a method for manufacturing the same.

  In the first aspect of the present invention, the above-described problem is solved by an optical control including an optical waveguide, an electro-optical element installed in the optical waveguide, and an adhesive that connects the optical waveguide and the electro-optical element. A component, wherein the adhesive includes a curable resin material, and an organic material that has substantially the same molecular structure as the resin material and suppresses the curing shrinkage of the resin material. The problem is solved by a light control component characterized by being cured.

  According to a second aspect of the present invention, the above-described problem is solved by installing an electro-optic element in an optical waveguide and filling a gap between the optical waveguide and the electro-optic element with a curable material; A step of curing the material, and the curable material has substantially the same molecular structure as the curable resin material and the resin material, and the organic material suppresses curing shrinkage of the resin material. It solves with the manufacturing method of the light control component characterized by including a material.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the optical control component with the reliable signal propagation, and its manufacturing method.

  FIG. 1A is a diagram schematically showing a cross section of the light control component (optical switch) 10, and FIG. 1B is a plan view thereof.

  Referring to FIGS. 1A and 1B, the light control component 10 has a structure in which an electro-optical element 12 is installed in a recess formed in the optical waveguide 11. In the optical waveguide 11, the illustration of the boundary between the core part and the clad part is omitted.

  In the above structure, the adhesive 13 made of a curable resin material is filled in the gap between the optical waveguide 11 and the electro-optical element 12, and the resin material is cured by heating or ultraviolet irradiation to fix the electro-optical element 12. Is done. However, the alignment of the optical waveguide 11 and the electro-optical element 12 requires accuracy on the order of submicrons, and thus there is a case where curing shrinkage becomes a problem in the conventional adhesive. For example, it is preferable that the electro-optical element 12 be accurately installed with respect to the optical axis 14 propagating through the optical waveguide 11.

  For example, in order to suppress the curing shrinkage of the adhesive (resin material) 13, a method of adding a powder (for example, silica) made of an inorganic material to the adhesive 13 is conceivable.

  FIG. 2A is a diagram schematically showing a structure formed by curing a curable resin, and FIG. 2B is an addition to the curable resin for suppressing curing shrinkage. It is the figure which showed typically the structure formed by adding and hardening | curing an agent. In the case of FIG. 2A, crosslinks are formed by functional groups of the base material in addition to the main chain of the curable resin (base material), and the crosslink density is increased. On the other hand, when an additive is added, the formation of crosslinks is inhibited by the additive and the crosslink density is reduced. For this reason, in the case of FIG. 2 (B), hardening shrinkage | contraction can be suppressed compared with the case of FIG. 2 (A).

  However, since the light that is a medium that propagates the signal passes through the adhesive 13, when powder made of an inorganic material is added, the amount of light is attenuated due to light scattering, or abnormal refraction of the optical path is caused. As a result, there is a concern that the reliability of the optical switch is lowered.

  Therefore, in the light control component according to the present invention, the adhesive 13 includes a curable resin material and an organic material that has substantially the same molecular structure as the resin material and suppresses curing shrinkage of the resin material. Is characterized in that it is configured to be cured.

  For example, the above organic material that is an additive material has substantially the same main molecular structure as a curable resin material that is a base material constituting an adhesive. For this reason, when light propagates through the adhesive, scattering / attenuation of light, abnormal refraction, and the like are suppressed.

  Further, by selecting a material that does not substantially contribute to the curing reaction of the curable resin material as an additive (the organic material described above), it is possible to suppress the curing shrinkage of the adhesive. For example, a material having a structure in which a functional group contributing to the curing reaction of the resin material is substituted with another functional group may be selected as the organic material. Alternatively, a material that does not have a functional group that contributes to the curing reaction of the curable resin material may be selected as the organic material.

  For example, in the case of a thermosetting resin or an ultraviolet curable resin, the initiator added to the base material (resin) is decomposed by heat or ultraviolet rays to generate ions, and a hardening reaction of the base material occurs. . For this reason, for example, by using a resin material having a molecular weight larger than that of the base material as an additive, components that do not contribute to the reaction after the curing reaction can remain, and curing shrinkage can be suppressed.

  Further, when the base material is a phthalic polyester adhesive, phthalic acid may be used as an additive. In the case of a bisphenol A-based thermosetting resin, bisphenol A may be used as an additive.

For example, as curable resin materials, there are resin materials such as thermosetting type, ultraviolet curable type, and condensation type. These resin materials are classified as “curable resin materials (base materials)” and “organic materials (additional). It may be combined as an agent). In the above combination, for example, the additive has a structure in which the functional group contributing to the curing reaction of the base material is replaced with another functional group. For example, when the base material is a thermosetting resin material As the additive, either an ultraviolet curable resin type or a condensation type resin material may be selected. When the base material is an ultraviolet curable resin material, a thermosetting or condensation type resin material may be selected as the additive. Similarly, when the base material is a condensation type resin material, a thermosetting or ultraviolet curable resin material may be selected as the additive.

  Since the adhesive has the above-described structure, curing shrinkage of the adhesive 13 is suppressed, and scattering / attenuation and anomalous refraction when light propagates through the adhesive 13 are suppressed. Becomes better.

  Moreover, as a base material (additive), resin materials, such as an epoxy resin type, a polyester type, a silicone rubber type, can be used, for example. The curable resin includes a one-pack type and a two-pack type, and any type may be used. In the case of a two-pack type, both the main agent and the curing agent may be used, or these may be used separately.

  3A to 3C are diagrams illustrating specific examples of the adhesive. FIG. 3A shows an example of the structure of a thermosetting epoxy resin.

  For example, in the structure shown in FIG. 3A, when the molecular weight represented by n is less than 1, the resin becomes liquid. Further, when the molecular weight represented by n is 1 or more, the resin is solid (for example, powder).

  For example, adding a powdery epoxy resin having a large molecular weight (n is 1 or more) to a liquid curable epoxy resin having a small molecular weight (n is less than 1) can slow the curing reaction. It is possible and the cure shrinkage of resin can be suppressed.

  FIG. 3B is a diagram showing a curing reaction of a two-component condensation type silicone resin. Referring to FIG. 3B, the two-pack type condensation type silicone resin is handled in two types, a main agent and a curing agent, and the main agent and the curing agent are mixed immediately before use (curing). . The curing reaction in this case is a condensation reaction of silanol and a hydrolyzable group-containing silicon compound, and alkoxysilane is mainly used as the crosslinking agent. In addition, water or other catalysts are used to promote the reaction.

  Further, as a curing reaction of the adhesive, a reaction as shown in FIG. 3C may be used. In the case shown in FIG. 3C, curing is caused by a mechanism of crosslinking siloxane chains by addition reaction of a polysiloxane containing a vinyl group and a polysiloxane having a Si—H bond.

  In this case, for example, a platinum compound is used as the catalyst. Moreover, since the curing rate is highly temperature dependent and cures in a shorter time as the temperature is raised, it can be used as a heat-curing adhesive by changing the amount and type of the catalyst.

  For example, by combining the resin shown in FIG. 3B and the resin shown in FIG. 3C, curing shrinkage of the adhesive can be suppressed.

  Next, the result of adding a curing agent to the base material to form a curable material, curing the material, and measuring the shrinkage rate and the light transmittance will be described.

  First, as Experiment A, a silicone resin as a main component of a two-component condensation type liquid silicone resin is added as an additive to a two-component heat-curable liquid silicone resin (main agent and curing agent) as a base material, and a curable material is obtained. Configured. The curable material was heated and cured under the conditions of a heating temperature of 100 ° C. and a heating time of 1 hour.

Further, as Experiment B, a solid type epoxy resin (having a molecular weight larger than that of the base material) was added as an additive to the one-component liquid ultraviolet curable epoxy resin that was a base material to constitute a curable material. At this time, in order to uniformly mix the solid resin with the liquid resin, a resin mixture in which the liquid resin and the solid resin were mixed at a predetermined ratio was dissolved in acetone to prepare a uniform mixed solution. Next, the mixed solution was decompressed at room temperature, and acetone as a solvent was removed by evaporation. In this way, a liquid epoxy resin and a solid epoxy resin were uniformly mixed to prepare an ultraviolet curable material. The curable material was cured by irradiating with an ultrahigh pressure mercury lamp at an output of 1 mW / cm ² for 15 minutes.

Further, as a comparative example, a curable material was configured by adding dry silica powder as an additive to a one-component ultraviolet curable epoxy resin as a base material. The curable material was cured by irradiating with an ultrahigh pressure mercury lamp at an output of 1 mW / cm ² for 15 minutes.

  FIG. 4 compares the shrinkage rate with respect to the additive addition rate (weight%, expressed as wt% in the figure) for the above-described Experiment A, Experiment B, and Comparative Example. FIG. 5 compares the light transmittance with respect to the additive addition rate (weight%, expressed as wt% in the figure) for the above-described Experiment A, Experiment B, and Comparative Example.

  Referring to FIG. 4, it can be seen that in each of Experiment A, Experiment B, and Comparative Example, the shrinkage ratio when cured is reduced as the additive addition ratio increases. Further, referring to FIG. 5, in the case of the comparative example, the transmittance decreases as the addition rate of the additive is increased, and in the case of the comparative example, the curing shrinkage rate is suppressed by the addition of the additive. It can be seen that the transmittance is lowered and it is difficult to apply to the light control element. On the other hand, in the case of Experiment A and Experiment B, it can be seen that the transmittance is hardly changed by the addition of the additive.

  From the above results, in Experiments A and B, it is possible to improve the light transmittance while suppressing the curing shrinkage of the curable material, and the signal propagation reliability is good. It was confirmed that it was possible to construct a light control component.

  Next, a method for manufacturing a light control component using the above adhesive and a configuration example of the light control component will be described.

  6A to 6H are diagrams illustrating a method of manufacturing a light control component (optical switch) according to the second embodiment, following a procedure. However, in the following drawings, the same reference numerals are given to the parts described above, and the description may be omitted.

6A to 6B, a slab optical waveguide 102 having a core part 102A and a cladding part 102B having different reflectivities is formed on a substrate 101 made of, for example, quartz. The optical waveguide 102 is composed of, for example, SiO ₂ as a main component, and the core portion 102A and the clad portion 102B are formed by changing the kind and ratio of the additive added to the SiO ₂ .

  In the above configuration, the core portion 102A having a high refractive index is sandwiched between the cladding portions 102B having a low refractive index, and light waves are propagated along the extending direction of the core portion 102A by total reflection of light. The

  Next, in the step shown in FIG. 6C, the optical waveguide 102 is etched by etching using a mask pattern (not shown) as a mask, and a part of the substrate 101 is etched as necessary to form the recess 103. . In this case, the substrate 101 is exposed from the bottom of the recess 103.

  Next, in the step shown in FIG. 6D, an electrode 104 made of Cu is formed on the substrate 101 exposed from the bottom of the recess 103, for example, by sputtering.

  6E to 6F, a conductive paste 104 such as Cu paste is applied on the electrode 104, and an electro-optic element 106 made of PLZT, for example, is placed on the conductive paste 104. The electro-optical element 106 is installed so as to be housed in the recess 103.

  Next, in the step shown in FIG. 6G, the curability is configured by adding a solid type epoxy resin (having a molecular weight larger than that of the base material) as an additive to the one-component liquid ultraviolet curable epoxy resin that is the base material. A material (adhesive) 107 is filled in a gap between the optical waveguide 102 and the electro-optic element 106 (a gap between the optical waveguide 102 and the substrate 101). Here, the optical waveguide 102 and the electro-optical element 106 are substantially connected, and a path for light propagation is secured by the curable material 107. The electrode 104 and the conductive paste 105 are embedded with a curable material (adhesive) 107.

Next, in the process shown in FIG. 6H, the curable material 107 was irradiated with an ultrahigh pressure mercury lamp at an output of 1 mW / cm ² for 15 minutes to be cured. In this way, the light control component (optical switch) 100 can be manufactured.

  FIG. 7 is a diagram schematically showing a plan view of the light control component 100 shown in FIG. 6H. In FIG. 7, illustration of the curable material (adhesive) 107 is omitted. Referring to FIGS. 6H and 7, the light control component 100 has a structure in which an electric field is generated in the electro-optical element 106 when a voltage is applied to the electrode 104, and light is switched.

  According to the manufacturing method described above, since the curing shrinkage of the curable material 107 is suppressed, the influence of the positional deviation of the optical optical element 106 with respect to the optical waveguide 102 is suppressed. Moreover, the light transmittance of the curable material 107 that transmits light is good. For this reason, according to said manufacturing method, it becomes possible to manufacture the light control component with the reliable signal propagation.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the specific embodiments described above, and various modifications and changes can be made within the scope described in the claims.
(Appendix 1)
An optical waveguide;
An electro-optic element installed in the optical waveguide;
An optical control component having an adhesive for connecting the optical waveguide and the electro-optic element,
The adhesive is
A light comprising: a curable resin material; and a material including a main molecular structure that is substantially the same as the resin material and an organic material that suppresses curing shrinkage of the resin material. Control part.
(Appendix 2)
The light control component according to appendix 1, wherein the organic material has a molecular weight larger than that of the resin material.
(Appendix 3)
The light control component according to appendix 1 or 2, wherein the resin material is liquid and the organic material is a solid resin material.
(Appendix 4)
The light control component according to any one of appendices 1 to 3, wherein the resin material is an epoxy resin material.
(Appendix 5)
The light control according to any one of appendices 1 to 4, wherein the organic material has a structure in which a functional group contributing to a curing reaction of the resin material is substituted with another functional group. parts.
(Appendix 6)
The light control component according to any one of appendices 1 to 5, wherein the resin material is a thermosetting resin material, and the second organic material is a condensation resin material.
(Appendix 7)
Installing an electro-optic element in the optical waveguide, and filling a gap between the optical waveguide and the electro-optic element with a curable material;
Curing the curable material,
The curable material includes a curable resin material, and an organic material that has substantially the same molecular structure as that of the resin material and suppresses curing shrinkage of the resin material. A manufacturing method for parts.
(Appendix 8)
Forming the optical waveguide on a substrate;
The method for manufacturing a light control component according to claim 7, further comprising: a step of etching the optical waveguide to form a recess for installing the electro-optic element.
(Appendix 9)
The method for manufacturing a light control component according to claim 8, further comprising a step of forming an electrode on the bottom of the recess.
(Appendix 10)
The method of manufacturing a light control component according to appendix 9, wherein the electro-optic element is connected to the electrode.
(Appendix 11)
11. The method for manufacturing a light control component according to claim 10, wherein the curable material is filled in a gap between the optical waveguide and the electro-optic element so as to embed the electrode.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the optical control component with the reliable signal propagation, and its manufacturing method.

(A) is sectional drawing of a light control component, (B) is the top view. (A) is the figure which showed typically the structure of resin when a crosslinking density is large, and (B) is a case where a crosslinking density is small. (A) to (C) are examples of curable resins. It is a figure which shows hardening shrinkage | contraction of resin. It is a figure which shows the light transmittance of resin. It is FIG. (1) which shows the manufacturing method of light control components. It is a figure (the 2) which shows the manufacturing method of light control components. It is FIG. (3) which shows the manufacturing method of light control components. It is FIG. (4) which shows the manufacturing method of light control components. It is FIG. (5) which shows the manufacturing method of light control components. It is FIG. (6) which shows the manufacturing method of light control components. It is FIG. (The 7) which shows the manufacturing method of light control components. It is FIG. (8) which shows the manufacturing method of light control components. It is a top view of a light control component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,100 Light control component 101 Board | substrate 11,102 Optical waveguide 102A Core part 102B Clad part 13,107 Adhesive 103 Recessed part 104 Electrode 105 Conductive paste 106 Electro-optical element

Claims (6)

An optical waveguide;
An electro-optic element installed in the optical waveguide;
An optical control component having an adhesive for connecting the optical waveguide and the electro-optic element,
The adhesive is
A light comprising: a curable resin material; and a material including a main molecular structure that is substantially the same as the resin material and an organic material that suppresses curing shrinkage of the resin material. Control part.   The light control component according to claim 1, wherein the organic material has a molecular weight larger than that of the resin material.   3. The light control component according to claim 1, wherein the resin material is liquid and the organic material is a solid resin material.   The light according to any one of claims 1 to 3, wherein the organic material has a structure in which a functional group contributing to a curing reaction of the resin material is substituted with another functional group. Control part. Installing an electro-optic element in the optical waveguide, and filling a gap between the optical waveguide and the electro-optic element with a curable material;
Curing the curable material,
The curable material includes a curable resin material, and an organic material having a molecular structure substantially the same as that of the resin material and suppressing cure shrinkage of the resin material. A manufacturing method for parts. Forming the optical waveguide on a substrate;
The method of manufacturing a light control component according to claim 5, further comprising: a step of etching the optical waveguide to form a recess for installing the electro-optic element.

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