JP2009053258A - Manufacturing method of optical signal path changing device, and optical signal path changing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optical signal path changing device which is high in the reliability of an electric connection between an optical deflecting element and a wiring on a substrate, and to improve the manufacture yield of the optical signal path changing device. <P>SOLUTION: In the case of manufacturing the optical signal path changing device, which includes the optical deflecting element, an incident portion and a projection portion for light, and a substrate mounted with the wiring for applying a voltage to one surface of the optical deflecting element, a solvent-free conductive paste containing an addition type thermosetting compound and a conductive material is sandwiched between the electrode on the one surface of the optical deflecting element and the wiring, and half-cured into a half-cured body having a glass transition point not higher than 0°C, and an underfill agent is flowed into a space formed between the optical deflecting element and substrate as the optical deflecting element is mounted on the substrate; and then an optical waveguide is positioned, the underfill agent is cured, and the conductive paste is subjected to final curing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical signal path changing device manufacturing method and an optical signal path changing device in optical communication.

  In recent years, the transmission band of optical communication has been steadily increasing, and with the progress of wavelength division multiplexing (WDM) technology, the speed and capacity have been increased. In order to construct a hardware infrastructure of an optical fiber network in a backbone communication network, an optical signal path changing device that switches an optical signal transmission destination is necessary. The optical signal path changing device is also called an optical signal switching device in the sense of switching the optical signal path. Sometimes simply called an optical switch.

  2. Description of the Related Art Conventionally, as an optical signal path changing device, an optical cross-connect device that converts an optical signal into an electrical signal, switches a signal transmission destination with a crossbar switch, and then converts the signal again into an optical signal has been mainstream. However, when the data transfer rate exceeds 10 Gb / s, it becomes difficult to configure a switching device using an electrical switching element as in the prior art.

  If the optical propagation path is switched using an optical switching element instead of an electrical switching element, conversion between light and electricity becomes unnecessary, and the optical cross does not depend on the speed (frequency) of the optical signal. A connect device can be configured. At present, an optical switch module with 32 input ports and 32 output ports (32 × 32 channels) has been realized, and such an optical switch module is connected in multiple stages to provide a non-blocking switch network (optical signal path change). There is also an example of constructing a device.

  In a conventional optical switch module, generally, a movable micromirror is used as an optical switching element. That is, the direction in which the optical signal propagates is switched by controlling the direction of the micromirror with an electric signal. Micromirrors are formed using MEMS (microelectromechanical systems) technology. The optical switch module is configured by arranging a large number of micromirrors in two directions (X direction and Y direction).

  In addition, a switching element (light deflecting element) using an electro-optic effect has been developed (see, for example, Patent Document 1). FIG. 1A is a plan view showing an example of an optical deflection element, and FIG. 1B is a sectional view of the same. As shown in FIGS. 1A and 1B, in the optical deflection element, an optical waveguide 5 having an electrooptic effect is formed on a conductive or semiconductive single crystal substrate 7, and an upper electrode 6 is further formed thereon. Has been. The upper electrode 6 is formed in a wedge shape (right triangle shape) having a side (referred to as a base) perpendicular to the optical axis of incident light and a side (referred to as a hypotenuse) that crosses obliquely.

In the optical deflection element configured as described above, light enters the optical waveguide 5 from the bottom side of the upper electrode 6 and exits from the oblique side of the upper electrode 6 as shown in FIG. 1A. By applying a voltage between the substrate 7 as the lower electrode and the upper electrode 6, the refractive index of the portion of the optical waveguide 5 below the upper electrode 6 changes, and there is a difference in refractive index from the surroundings. Arise. The light passing through the optical waveguide 5 is refracted at the portion where the refractive index changes, and the traveling direction changes. That is, the light emission direction can be controlled by changing the voltage applied between the upper electrode 6 and the substrate 7.
JP 2002-318398 A (Claims)

  When manufacturing the above optical signal path changing device, alignment of the incident path (waveguide) of the incident light with the optical waveguide of the optical deflection element and the optical waveguide of the optical deflection element and the output path (waveguide) of the outgoing light To the micron order. Specifically, when installing a light deflection element between the light incident path and light emission path placed on the substrate, the dielectric constant is kept low when voltage is applied to the light deflection element, and the optical signal path is changed. In order to prevent breakdown of the device, a resin (underfill agent) is injected between the optical deflection element and the substrate, the optical deflection element is aligned with the conductive paste placed on the substrate, and the light Alignment is performed so that light incident through the incident path reaches the light exit path through the optical waveguide portion of the light deflection element, and then the conductive paste and the underfill agent are cured to place the light deflection element on the substrate. Fix it.

  At this time, the light deflection element and the wiring on the substrate are electrically connected with a cured product of the conductive paste, but this electrical connection often fails. As a result of investigation, electrical connection does not work well because of the surface tension when the underfill agent is injected between the light deflecting element and the substrate, or between the cured paste of the conductive paste and the substrate or the conductive paste. It was found that this is because an underfill agent entered between the cured product and the light deflection element.

  The present invention aims to provide a method for solving the above problems. Still other objects and advantages of the present invention will become apparent from the following description.

According to one aspect of the present invention, an optical deflection element that deflects light by a change in refractive index caused by voltage application, an incident portion for entering light into the optical deflection element, and light is emitted from the optical deflection element And a manufacturing method of an optical signal path changing device comprising a substrate on which wiring for applying a voltage to one surface of the light deflection element is placed,
The light deflection element is provided with electrodes for applying a voltage to both sides thereof,
Solvent-free comprising an addition-type thermosetting compound and a conductive material for electrically connecting the electrode to the wiring between the electrode on one surface of the light deflection element and the wiring Sandwich the conductive paste of
Before, during, or after the sandwiching, the conductive paste is semi-cured to form a semi-cured product having a glass transition point of 0 ° C. or less,
Thereafter, an underfill agent is poured into the space between the optical deflection element and the substrate, which is generated by the sandwiching,
Then, align the optical waveguide,
Thereafter, curing the underfill agent and final curing of the conductive paste,
A method of manufacturing an optical signal path changing device is provided.

  According to the aspect of the present invention, an optical signal path changing device with high reliability of electrical connection between the optical deflection element and the wiring on the substrate can be obtained, and the manufacturing yield of the optical signal path changing device can be improved.

The modulus at 50% elongation at room temperature of the semi-cured product of the conductive paste is between 5.0 and 50.0 N / cm ² , and between the semi-curing and the final curing of the conductive paste. The linear shrinkage rate is 0.5% or less, and the addition-type thermosetting compound is a liquid resin, liquefied silicone resin, liquid urethane rubber, styrene and butadiene containing acrylonitrile and butadiene as main components. Selected from the group consisting of a liquid resin containing as a main component, a liquid resin containing 1,2-polybutadiene as a main component, a liquid resin containing polychloroprene as a main component, and a mixture thereof. It is preferable.

  According to another aspect of the present invention, an optical signal path changing device manufactured by the above method is provided.

  According to the present invention, an optical signal path changing device with high reliability of electrical connection between an optical deflection element and a wiring on a substrate can be obtained, and the manufacturing yield of the optical signal path changing device can be improved.

  Embodiments of the present invention will be described below with reference to the drawings, examples and the like. In addition, these figures, Examples, etc. and description illustrate the present invention, and do not limit the scope of the present invention. It goes without saying that other embodiments may belong to the category of the present invention as long as they match the gist of the present invention. In the drawings, the same symbol represents the same element.

According to the present invention, an optical deflection element that deflects light by a change in refractive index due to voltage application, an incident part for entering light into the optical deflection element, and an emission for emitting light from the optical deflection element And an optical signal path changing device including a substrate on which wiring for applying a voltage is applied to one surface of the optical deflection element,
The light deflection element is provided with electrodes for applying a voltage to both sides thereof,
An additive thermosetting compound and a conductive material for electrically connecting the electrode to the wiring on the substrate are included between the electrode on one surface of the light deflection element and the wiring. Insert a solvent-free conductive paste
Before, during, or after the sandwiching, the conductive paste is semi-cured to form a semi-cured product having a glass transition point of 0 ° C. or less,
An underfill agent is poured into the space between the light deflection element and the substrate, which is generated by the sandwiching,
Then, align the optical waveguide,
Thereafter, the underfill agent is cured and the conductive paste is finally cured.

  From an incident part for making light incident on the optical deflection element, an emission part for emitting light from the optical deflection element, and a substrate on which a wiring for applying a voltage to one surface of the optical deflection element is placed The state of this part is illustrated in FIGS. 2 and 3, the wiring 2 is provided on the substrate 1. The incident portion 3 and the emission portion 4 are installed on the substrate 1 with the wiring 2 interposed therebetween. However, the condition that the incident portion 3 and the emission portion 4 are arranged on the substrate 1 with the wiring 2 interposed therebetween is not essential. The relationship between the incident portion 3 and the emission portion 4 and the wiring 2 is arbitrary, and may be any arrangement relationship. 2 to 7, the dotted line in the horizontal direction indicates the waveguide for the incident portion 3 and the emission portion 4.

  For example, an optical fiber can be connected to the incident portion 3 and the emission portion 4, but any component can be used as long as it can introduce light into the incidence portion 3 and extract light from the emission portion 4. Good.

  The light deflection element is placed on the substrate of the portion composed of the incident part, the emission part, and the substrate. The light deflection element is provided with electrodes for applying a voltage to both sides thereof, and the refractive index of the light deflection element is changed by applying a voltage between both electrodes, and the light is changed by the change of the refractive index. Can be deflected.

  The optical deflection element according to the present invention comprises an optical waveguide portion and electrodes on both sides thereof. An example is shown in FIGS. 1A and 1B. In FIG. 1B, electrodes 6 and 7 are drawn on both sides of the optical waveguide portion 5. The electrode 7 also serves as a substrate that supports the optical waveguide portion 5. In that sense, the electrode 7 can also be called an optical waveguide support substrate.

  The material of the optical waveguide portion is not particularly limited as long as the light transmittance is so high that there is no practical problem and exhibits the Pockels effect (electro-optic effect), and a PLZT optical element is mainly used. The shape of the optical waveguide portion is not particularly limited as long as it matches the purpose of the present invention, and the shape of the electrode is important because the region where the refractive index changes is determined by the shape of the electrode. Usually, the electrode on one surface (electrode 7) is a common electrode that covers the optical waveguide portion on one surface, and the region where the refractive index changes is determined by the shape of the electrode (electrode 6) on the other surface. The shape of the electrode 6 is often a right triangle as described above, but may be other shapes. The electrode 7 may be divided into a plurality of parts and may have the same shape as the electrode 6.

  The light passing through the optical waveguide portion is an optical deflection element surface orthogonal to this right triangle (hereinafter, the optical deflection element surface generally seen when viewed from the direction orthogonal to the surface with the electrodes is referred to as “surface”. The plane perpendicular to the surface is referred to as a “cross section”), but the passage position on the cross section is not particularly limited as long as it is the optical waveguide portion. However, since the thickness of the cross section of the optical waveguide portion is usually about several μm, strict adjustment is required for alignment of the optical waveguide of the incident portion and the optical waveguide of the output portion with the cross section of the optical waveguide portion. For example, by observing the light from the incident part from the emission part side and confirming that the light has arrived (or the intensity of the observed light is maximized), the optical waveguide of the incident part and the emission part It can be understood that the optical waveguide and the cross section of the optical waveguide portion of the optical deflection element are well aligned. Note that the optical waveguide at the entrance and the optical waveguide at the exit are aligned in advance. Since the alignment is performed in a state where no voltage is applied, this “optical waveguide of the emission part” is the optical waveguide of the emission part when the light is not deflected.

  In this manner, the optical waveguide at the entrance and the optical waveguide at the exit can be aligned with the cross section of the optical deflection element, and the conductive paste on the optical deflection element (or a semi-cured product or a final cured product thereof) If the positional connection with the wiring is taken, the alignment of the optical deflection element is completed.

  The light deflection element according to the present invention is provided with electrodes for applying a voltage to both surfaces thereof, and one of the electrodes (the side facing the substrate) is electrically connected to the wiring on the substrate. The other electrode is connected to other components for applying a voltage. In many cases, the other electrode itself serves as a substrate (optical waveguide support substrate) for supporting the optical waveguide portion. There is no restriction | limiting in particular as a material of the electrode which concerns on this invention, A well-known thing can be used. Gold, copper, ITO or the like is often used for the electrode 6 on the side facing the substrate of FIG. 1B, and Nb / STO or the like is often used for the electrode 7 on the opposite side in the case of a PLZT optical element. .

  Although there may be a plurality of light deflecting elements according to the present invention, it is easy to provide a plurality of regions having different refractive indexes by providing a plurality of electrodes, and thus it is not worth providing a plurality of light deflecting elements. In the case where there are a plurality of light deflection elements, another part may or may not intervene in the passage of light between the light deflection elements.

  The incident portion according to the present invention means a portion having a function of introducing light into the light deflection element, and may have any other function. In addition to a simple optical fiber, a waveguide in which a plurality of core portions are wrapped with a clad layer or a collimating lens as described later may be used. The same applies to the emission part according to the present invention.

  The light deflection element is placed on the substrate. At that time, an additive-type thermosetting compound and a conductive material for electrically connecting the electrode to the wiring on the substrate are included between the electrode on one surface of the optical deflection element and the wiring. A solvent-free conductive paste consisting of

  For this purpose, a conductive paste is often placed on the wiring in advance. Please refer to FIG. In FIG. 4, the conductive paste 8 is disposed on the wiring 2 of the substrate 1. For this arrangement, a known method such as screen printing or a dispenser method can be employed.

  Thereafter, the light deflection element is placed on the substrate so that the electrode of the light deflection element is in contact with the conductive paste. 4 shows a plan view (left side) and a cross-sectional view (right side) of the light deflection element. From the plan view of the optical deflection element, it can be seen that there are twelve regions in which the refractive index can be changed in this example. The electrode 6 is indicated by a circle, but this is for simplification and does not indicate the actual shape.

  FIG. 5 illustrates the state of placement. In FIG. 5, the electrode 6 of the light deflection element 9 is placed in contact with the conductive paste 8 on the wiring 2 of the substrate 1. Although a method of arranging the conductive paste on the light deflection element in advance may be adopted, the former is more advantageous from the viewpoint of easy positioning. Note that a terminal portion for contacting the conductive paste may be provided on the electrode. In the present invention, the term “electrode” may be considered including this “terminal portion”.

  Before, during or after the sandwiching, the conductive paste is semi-cured to obtain a semi-cured product having a glass transition point of 0 ° C. or less. “Semi-cured” means that curing has progressed to some extent. Semi-curing is performed to prevent the conductive paste from being dissolved or deformed by an underfill agent to be injected later. Further, even before the underfill agent is injected, the shape given to the conductive paste may be maintained to some extent.

  The degree of curing may be appropriately selected according to the actual situation. Whether semi-curing is performed before, during or after sandwiching may be appropriately determined according to the actual situation. It may be performed continuously through any of the stages before, during or after the sandwiching, or may be performed a plurality of times. Semi-curing is usually performed by heating, but the conditions are not particularly limited. In general, the glass transition point does not change so much after curing has progressed to some extent.

  In terms of time, if the fluidity of the conductive paste is large and the shape is liable to collapse, it may be better to perform it before sandwiching. However, if it is hardened too much, it will be difficult to deform when aligning the light deflection element, so care must be taken.

  Thereafter, the underfill agent is poured into the space between the light deflection element and the substrate, which is generated by placing the light deflection element on the substrate, and then the optical waveguide is aligned, and then the underfill agent is cured. And final curing of the conductive paste. FIG. 6 shows a state after the underfill agent 10 is poured into the space between the light deflection element and the substrate, and FIG. 7 shows a state after the alignment. The dotted line in the horizontal direction in FIG. 7 indicates that the optical waveguide portion of the light deflection element has been aligned with the incident portion and the emission portion, and the light emitted from the incidence portion has been observed with the CCD camera. In contrast, in FIG. 6, it is understood that the dotted lines are not single and alignment is not possible.

  There is no particular restriction on the method of pouring the underfill agent, but since the viscosity of the underfill agent is usually not so high, it is sufficient to inject the underfill agent into the space between the light deflection element and the substrate by some means. It is.

  Any method may be employed for alignment of the optical waveguide, but as described above, light from the incident part is observed or arrived from the exit part side while applying force from above. By confirming that the intensity of the obtained light is maximized, it can be understood that the optical waveguide of the incident part and the optical waveguide of the output part and the cross-section of the optical waveguide part of the optical deflection element are well aligned. In FIG. 7, the light from the incident part is observed from the exit part side with a CCD camera to confirm that the light has arrived.

  Subsequent curing of the underfill agent and final curing of the conductive paste are usually performed by heating, but other energy such as light may be used. The end point of the curing of the underfill agent and the final curing of the conductive paste may be arbitrarily determined according to the actual situation.

  The conductive paste according to the present invention can be appropriately selected from so-called conductive pastes containing a conductive material and a thermosetting compound. Examples of the conductive material include conductive particles such as silver, gold, copper, and carbon. The amount of the conductive particles can be appropriately selected depending on the required level of conductivity, but is usually between 40 and 90% by weight in the conductive paste.

  The conductive paste according to the present invention does not contain a solvent. In a conductive paste containing a solvent, the dimensions of the cured product change according to the escape of the solvent during curing, and the alignment of the optical waveguide of the incident part and the optical waveguide of the output part with the cross section of the optical waveguide part of the optical deflection element There is a risk of failure. Moreover, since it takes a long time to escape the solvent, it is not preferable in terms of production efficiency.

  The addition type thermosetting compound contained in the conductive paste according to the present invention may be a mixture of plural kinds. The “additional type” mentioned here means that the third component is not generated when the substances react with each other. The reaction between compounds having an unsaturated bond such as a double bond belongs to this. Those that generate urethane bonds as a result of the reaction and do not generate a third component also belong to this category. Since the reaction between an acid and an alcohol or the reaction between an ester and an alcohol produces water or an alcohol as a third component, it does not belong to this category. The reason why the “addition type” thermosetting compound is used is that there is a problem of dimensional change (shrinkage) of the cured product and a problem of production efficiency as in the case of the solvent.

  In the present invention, it is included in the requirement that a semi-cured product having a glass transition point of 0 ° C. or lower when the conductive paste is semi-cured. Although this condition depends on the degree of curing, it largely depends on the addition-type thermosetting compound according to the present invention. Therefore, it is important to select an appropriate addition-type thermosetting compound from this viewpoint. Whether the glass transition point of the semi-cured product is 0 ° C. or less can be confirmed by a model test.

  When the glass transition point of the semi-cured product is 0 ° C. or lower, when the underfill agent is injected between the light deflecting element and the substrate, the cured product of the conductive paste and the substrate are affected by the surface tension of the underfill agent. It is possible to prevent the underfill agent from entering between. This is because the cured product of the conductive paste has elasticity, and the distance between the cured product of the conductive paste and the substrate is caused by the surface tension when the underfill agent is injected between the light deflection element and the substrate. Even if it increases, it is surmised that it is because the hardened | cured material of an electrically conductive paste can remain firmly attached to a board | substrate or an optical deflection element. The elasticity of the cured product of the conductive paste may typically be referred to as “rubber elasticity”. On the other hand, conventional non-rubber resins such as epoxy resins and polyester resins peel off the cured paste of the conductive paste from the substrate and / or the light deflecting element and break the electrical connection. Let's go.

  A so-called rubber material can be used as the addition-type thermosetting compound according to the present invention. The addition-type thermosetting compound according to the present invention includes a liquid resin containing acrylonitrile and butadiene as main components, a liquid silicone resin, a liquid urethane rubber, a liquid resin containing styrene and butadiene as main components, Examples thereof include those selected from the group consisting of a liquid resin containing 2-polybutadiene as a main constituent, a liquid resin containing polychloroprene as a main constituent, and a mixture thereof.

  “Contained as a main constituent” means that 50% by weight or more of all components are components named as acrylonitrile and butadiene. 80% by weight or more of the named component is preferable, and 90% by weight or more of the named component is more preferable. The liquid silicone resin can be appropriately selected from so-called silicone liquids.

  These substances are appropriately selected from so-called liquid acrylonitrile-butadiene rubber, addition-type liquid silicone rubber, urethane rubber, liquid styrene-butadiene rubber, liquid 1,2-polybutadiene rubber, liquid polychloroprene rubber, and mixtures thereof. can do.

In addition, from the viewpoint of the physical properties of the semi-cured product of the conductive paste, the modulus at 50% elongation at room temperature is preferably between 5.0 and 50.0 N / cm ² . If it is smaller than this range, it may be too soft, and if it is larger than this range, it may be too hard, making it difficult to align the light deflection element.

  Further, from the viewpoint of shrinkage, it is preferable that the linear shrinkage rate from the semi-curing to the final curing of the conductive paste is 0.5% or less. If this range is exceeded, alignment of the optical deflection element can be difficult. The linear shrinkage rate between the semi-curing and final curing of the conductive paste can be adjusted by selecting the level of semi-curing as well as the material used for the conductive paste.

  In addition, since hardening is often performed by heating, it is necessary to consider the coefficient of thermal expansion, but by using an underfill with a small coefficient of thermal expansion, misalignment due to the thermal expansion of the conductive paste can be suppressed. .

  In the conductive paste according to the present invention, a third component other than the above may be present unless it is contrary to the spirit of the present invention. Unless it is contrary to the gist of the present invention, a thermosetting compound other than the addition-type thermosetting compound may be present, but it is generally not preferable. Even if a compound that is not a thermosetting compound is mixed, there is a case in which the conductive paste itself is cured or hardened in appearance as a result. For example, when a non-crosslinkable compound is used together with a crosslinkable compound. As a result, it may be one that does not contribute to curing. For example, it may contribute to increase the elasticity of the cured product of the conductive paste, and may be preferable. Moreover, it can also be useful to control the shape imparting property by changing the viscosity of the conductive paste according to the present invention. A thermoplastic polymer can be considered as such. Furthermore, the conductive paste according to the present invention may contain a catalyst or a reaction accelerator for initiating and / or promoting the reaction of contained substances.

  What is necessary is just to select suitably the viscosity of the electrically conductive paste which concerns on this invention according to the actual condition. As shown in FIG. 5, it is possible to contact the electrode of the light deflection element and the wiring on the substrate, and finally the alignment between the light incident path and the light emission path and the light deflection element can be performed, and it does not cause a short circuit due to excessive spread. Anything is acceptable.

  The underfill agent according to the present invention is sometimes referred to as dielectric breakdown prevention oil because it aims to lower the dielectric constant of the system and prevent dielectric breakdown of the optical signal path changing device.

  The underfill agent according to the present invention is required to have strong adhesiveness, and low curing shrinkage and low thermal expansion. If the linear shrinkage rate is large during curing, the alignment of the optical deflecting element will be misaligned. Further, since curing is often performed by heating, it is preferable that the coefficient of thermal expansion is small. As the underfill agent, an epoxy resin or an acrylic resin is generally used, and generally a linear shrinkage rate of 0.5% or less and a thermal expansion rate of 100 ppm / ° C. or less are preferable.

  The optical signal path changing device manufactured by the method according to the present invention has high reliability of electrical connection between the optical deflection element and the wiring on the substrate. Therefore, the manufacturing yield of the optical signal path changing device is also improved.

  Next, although the Example and comparative example of this invention are explained in full detail, this invention is not limited by these.

[Example 1]
Detailed examples of the optical signal path changing apparatus according to the present invention will be described below. FIG. 8 is a schematic diagram showing an optical switch module which is an example of the configuration of the optical signal path changing device according to the present invention. This optical switch module includes an incident side optical waveguide unit 101, a collimator unit 102, an incident side optical deflection element unit 103, a common optical waveguide 104, an output side optical deflection element unit 105, a condensing unit 106, and an output side optical waveguide unit 107. It is configured. These incident-side optical waveguide section 101, collimating section 102, incident-side optical deflection element section 103, common optical waveguide 104, exit-side optical deflection element section 105, condensing section 106, and exit-side optical waveguide section 107 are placed on the substrate. It is integrally formed.

  The incident-side optical waveguide unit 101 includes a plurality of optical waveguides (cores) 101a and a clad layer 101b that covers these optical waveguides 101a and confines light in the optical waveguide 101a due to a difference in refractive index. . Similarly, the output-side optical waveguide unit 107 includes a plurality of optical waveguides (cores) 107a, and a clad layer 107b that covers these optical waveguides 107a and confines light in the optical waveguide 107a due to a difference in refractive index. It is comprised by.

  In the present embodiment, it is assumed that the number of the optical waveguides 101a in the incident side optical waveguide unit 101 is the same as the number of the optical waveguides 107a in the output side optical waveguide unit 107. Hereinafter, the number of optical waveguides 101a (= the number of optical waveguides 107a) is n (n is an integer of 2 or more). However, the present invention is not limited to this, and the number of incident side optical waveguides may be different from the number of output side optical waveguides.

  The collimator 102 is composed of n collimator lenses 102a. Each collimating lens 102a is disposed at a position slightly away from the end of the optical waveguide 101a. The light emitted from the optical waveguide 101a spreads radially, but becomes parallel light by the collimating lens 102a.

  The incident-side light deflection element unit 103 is provided with n light deflection elements 103a. Each light deflection element 103a is disposed at a position slightly away from the collimating lens 102a in the optical axis direction. Although the detailed description of the optical deflection element 103a will be described later, the optical deflection element 103a changes the propagation direction of the optical signal using the Pockels effect (electro-optic effect).

  The common optical waveguide 104 is composed of a slab type waveguide. The common optical waveguide 104 transmits light that has passed through the incident-side light deflection element unit 103 to the emission-side light deflection element unit 105. A plurality of optical signals pass through the common optical waveguide 104 at the same time, but these optical signals travel straight through the common optical waveguide 104 in a predetermined direction, so that they are transmitted without interfering with other optical signals.

  The exit side optical deflection element unit 105 is provided with n optical deflection elements 105a. These light deflecting elements 105a deflect the light that has reached the light deflecting element 105a through the common optical waveguide 104 in a direction parallel to the optical waveguide 107a. The light deflection elements 103a and 105a have basically the same structure.

  The condensing part 106 is comprised by the n condensing lens 106a. These condensing lenses 106a have a function of condensing the light that has passed through the light deflection element 105a and guiding it to the optical waveguide 107a.

  With reference to FIGS. 9 and 10, details of the collimating unit 102, the incident side light deflection element unit 103, the emission side light deflection element unit 105, and the light collecting unit 106 will be described.

  As shown in FIGS. 9 and 10, the collimating lens 102 a configuring the collimating unit 102 is a two-dimensional lens including two portions 102 c and 102 d having different refractive indexes. The high refractive index portion (convex lens portion) 102c is formed of the same material as the optical waveguides (cores) 101a and 107a, and the low refractive index portion 102d can collimate light due to the difference in refractive index from the high refractive index portion 102c. It is made of a simple material.

  Similarly to the collimating lens 102a, the condensing lens 106a of the condensing unit 106 is also composed of a high refractive index portion (convex lens portion) 106c and a low refractive index portion 106d. However, in the condensing lens 106a, the direction of the lens is opposite to that of the collimating lens 102a.

  The light deflection element 103a constituting the incident side light deflector 103 is composed of one or a plurality of prism pairs 103p. As shown in FIG. 3, one prism pair 103p includes a slab waveguide 103b formed of a material having an electro-optic effect, and first and second slab waveguides 103b formed above the slab waveguide 103b. The upper electrodes 103c and 103d and the first and second lower electrodes 103e and 103f formed below the slab waveguide 103b are configured. The first and second upper electrodes 103c, 103d and the first and second lower electrodes 103e, 103f are both formed in a right triangle shape (wedge shape).

  The first upper electrode 103c and the first lower electrode 103e are opposed to each other with the slab waveguide 103b interposed therebetween. The first upper electrode 103c and the second upper electrode 103d are arranged close to each other with their hypotenuses facing each other, and the second upper electrode 103d and the second lower electrode 103e are slab-type waveguides 103b. It faces each other across the. The slab waveguide 103b is common to each prism pair 103p.

  Similarly to the incident side optical deflection element 103a, the optical deflection element 105a of the emission side optical deflection unit 105 is also composed of a slab waveguide formed of a material having an electro-optic effect and one or a plurality of prism pairs 105p. Yes. Each prism pair 105p includes a pair of first electrodes (a first upper electrode and a second lower electrode) and a pair of second electrodes (a second upper electrode and a second lower electrode). ing.

[Example 2]
An optical signal path changing device was manufactured according to FIGS. As the conductive paste, a silver paste (containing about 80% by weight of silver) using an addition-type liquid silicone rubber as a base material was used.

  A silver bump (conductive paste) having a diameter of about 100 μm and a height of 50 μm was formed on a predetermined wiring portion of the substrate on which wiring was formed, using a syringe.

  The light deflection element was sucked with a vacuum chuck, and was closely bonded to such an extent that the head portion of the silver bump was crushed, and the silver paste was semi-cured at 70 ° C. for 30 minutes while maintaining the gap.

  Next, an epoxy resin-based underfill agent is filled, an optical signal is incident from the incident side while the optical deflecting element is gradually pushed by the pressing device, and the optical waveguide is passed by the CCD camera on the outgoing side. The incoming light was verified and fixed at the optimal position. Thereafter, heating was performed at 150 ° C. for 1 hour, and final curing of the silver paste and curing of the underfill agent were performed.

  As a result, the alignment of the incident portion and the emitting portion with the light deflection element was completely performed, and all the 12 silver paste bumps were in electrical communication with the wiring of the substrate.

In addition, it was -55 degreeC when the glass transition point was measured separately about the semi-hardened material obtained by processing the said silver paste to the said semi-hardened state using a differential scanning calorimeter (DSC apparatus). . Further, the modulus at 50% elongation was measured using a tensile tester and found to be 9.0 N / cm ² . Furthermore, as a result of heat-treating this semi-cured product to a final cured product, the linear shrinkage rate was 0.1% or less.

[Comparative Example 1]
The same operation as in Example 2 was performed except that a silver paste having an unsaturated polyester resin as a base material was used as the conductive paste. In this case, in the close adhesion shown in FIG. 5, all the bumps were electrically connected, but after filling the underfill agent, all the electrical contacts were cut off.

  Separately, when the glass transition point of the semi-cured product obtained by treating the silver paste containing the unsaturated polyester resin as a base material to the semi-cured state was measured using the same apparatus as in Example 2, 110 was obtained. ° C. Further, since the fracture occurred before 50% elongation, the modulus at 50% elongation was not measurable. Furthermore, as a result of heat-treating this semi-cured product to a final cured product, the linear shrinkage rate was 0.1% or less.

  In addition, the invention shown to the following additional remarks can be derived from the content disclosed above.

(Supplementary Note 1) An optical deflecting element that deflects light by a change in refractive index due to voltage application, an incident part for making light incident on the optical deflecting element, and an emitting part for emitting light from the optical deflecting element; A method of manufacturing an optical signal path changing device including a substrate on which wiring for applying a voltage is applied to one surface of the optical deflection element,
The light deflection element is provided with electrodes for applying a voltage to both sides thereof,
Solvent-free comprising an addition-type thermosetting compound and a conductive material for electrically connecting the electrode to the wiring between the electrode on one surface of the light deflection element and the wiring Sandwich the conductive paste of
Before, during, or after the sandwiching, the conductive paste is semi-cured to form a semi-cured product having a glass transition point of 0 ° C. or less,
Thereafter, an underfill agent is poured into the space between the optical deflection element and the substrate, which is generated by the sandwiching,
Then, align the optical waveguide,
Thereafter, curing the underfill agent and final curing of the conductive paste,
Manufacturing method of optical signal path changing device.

(Additional remark ² ) The manufacturing method of the optical signal path changing apparatus of Additional remark 1 whose modulus at the time of 50% expansion | extension at room temperature of the semi-hardened | cured material of the said electrically conductive paste is between 5.0-50.0N / cm < ² >. .

  (Additional remark 3) The manufacturing method of the optical signal path changing apparatus of Additional remark 1 or 2 whose linear shrinkage rate between the said semi-hardening of the said electrically conductive paste and the said final hardening is 0.5% or less.

  (Appendix 4) The addition-type thermosetting compound is a liquid resin containing acrylonitrile and butadiene as main components, a liquid silicone resin, a liquid urethane rubber, a liquid resin containing styrene and butadiene as main components, 1, 2-polybutadiene as a main constituent, a liquid resin containing polychloroprene as a main constituent, and a group consisting of a mixture thereof, Manufacturing method of optical signal path changing device.

  (Additional remark 5) The optical signal path changing apparatus manufactured by the method in any one of Additional remarks 1-4.

FIG. 3 is a schematic plan view showing an optical deflection element. It is a typical cross-sectional view showing an optical deflection element. From an incident part for making light incident on the optical deflection element, an emission part for emitting light from the optical deflection element, and a substrate on which a wiring for applying a voltage to one surface of the optical deflection element is placed It is a typical top view which shows the mode of the part which becomes. From an incident part for making light incident on the optical deflection element, an emission part for emitting light from the optical deflection element, and a substrate on which a wiring for applying a voltage to one surface of the optical deflection element is placed It is a typical cross-sectional view which shows the mode of the part which becomes. It is a schematic diagram which shows a mode that the electrically conductive paste is arrange | positioned on the wiring of a board | substrate. It is a schematic diagram which shows a mode that the light deflection | deviation element was mounted on the board | substrate so that the electrode of a light deflection | deviation element may contact | connect an electrically conductive paste. It is a schematic diagram showing the state after pouring an underfill agent into the space between the light deflection element and the substrate. It is a schematic diagram showing the state after the alignment of an optical deflection element is completed. It is a schematic diagram which shows the optical switch module which is an example of a structure of the optical signal path changing apparatus which concerns on this invention. It is a schematic diagram which shows the optical switch module which is an example of a structure of the optical signal path changing apparatus which concerns on this invention. It is a schematic diagram which shows the relationship between the collimating part 102 and the incident side light deflection | deviation element part 103. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Wiring 3 Incident part 4 Outgoing part 5 Optical waveguide part 6 Electrode 7 Electrode 8 Conductive paste 9 Optical deflection element 10 Underfill agent 101 Incident side optical waveguide part 101a Optical waveguide (core)
101b Cladding layer 102 Collimating part 102a Collimating lens 102c High refractive index part (convex lens part)
102d Low refractive index portion 103 Incident side optical deflection element portion 103a Optical deflection element 103b Slab waveguide 103c, 103d
Upper electrode 103e, 103f
Lower electrode 103p Prism pair 104 Common optical waveguide 105 Emission side optical deflection element part 105a Optical deflection element 105p Prism pair 106 Condensing part 106a Condensing lens 106c High refractive index part (convex lens part)
106d Low refractive index portion 107 Output side optical waveguide portion 107a Optical waveguide (core)
107b cladding layer

Claims (5)

An optical deflection element that deflects light by a change in refractive index caused by voltage application, an incident part for making light incident on the optical deflection element, an emission part for emitting light from the optical deflection element, and the optical deflection A manufacturing method of an optical signal path changing device comprising a substrate on which wiring for applying a voltage to one surface of an element is placed,
The light deflection element is provided with electrodes for applying a voltage to both sides thereof,
Solvent-free comprising an addition-type thermosetting compound and a conductive material for electrically connecting the electrode to the wiring between the electrode on one surface of the light deflection element and the wiring Sandwich the conductive paste of
Before, during, or after the sandwiching, the conductive paste is semi-cured to form a semi-cured product having a glass transition point of 0 ° C. or less,
Thereafter, an underfill agent is poured into the space between the optical deflection element and the substrate, which is generated by the sandwiching,
Then, align the optical waveguide,
Thereafter, curing the underfill agent and final curing of the conductive paste,
Manufacturing method of optical signal path changing device. The method of manufacturing an optical signal path changing device according to claim 1, wherein the semi-cured product of the conductive paste has a modulus at 50% elongation at room temperature of 5.0 to 50.0 N / cm ² .   The method of manufacturing an optical signal path changing device according to claim 1 or 2, wherein a linear shrinkage ratio between the semi-curing and the final curing of the conductive paste is 0.5% or less.   The addition type thermosetting compound is a liquid resin containing acrylonitrile and butadiene as main constituents, a liquid silicone resin, a liquid urethane rubber, a liquid resin containing styrene and butadiene as main constituents, 1,2-polybutadiene. The optical signal path according to any one of claims 1 to 3, wherein the optical signal path is selected from the group consisting of a liquid resin containing as a main component, a liquid resin containing polychloroprene as a main component, and a mixture thereof. Manufacturing method of change device.   An optical signal path changing device manufactured by the method according to claim 1.

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