JP2008122721A - Substrate for optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate for an optical element in which an optical fiber used for optical communication and the optical element to be mounted on a light reflecting surface can precisely and securely be positioned. <P>SOLUTION: Disclosed is the substrate 1 for the optical element which is made of a resin-made molding (s) having a top surface 2 (2a) where the optical element 24 is mounted and a reverse surface 3 and has a plurality of insertion grooves 10 for optical fibers 20 which are formed on the top surface 2 (2b) of the molding (s), vertical fiber stop surfaces 12 which are disposed at respective ends of the plurality of insertion grooves 10 and in contact with end surfaces of inserted optical fibers 20, and the light reflecting surface 8 which is adjacent to the fiber stop surfaces 12 of the insertion grooves 10 for the optical fibers and tilts as it spreads toward the top surface 2 (2a) side of the molding (s). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical element substrate capable of accurately aligning an optical fiber used for optical communication, a light reflecting surface, and an optical element to be mounted.

  Conventionally, in order to provide an optical transmission module that is excellent in productivity and inexpensive while ensuring alignment accuracy of an optical fiber used for optical communication, a light reflecting surface, and an optical element, the fixing groove and the optical path of the optical fiber are converted. In manufacturing an optical fiber holding member having an inclined reflecting surface, a semiconductor process and a method of performing anisotropic etching on a crystal substrate having a predetermined orientation have been proposed (for example, see Patent Document 1).

Japanese Patent No. 3677348 (pages 1 to 12, FIGS. 1 to 5)

As described in Patent Document 1, when a crystal substrate is anisotropically etched to form a light reflecting surface having a substantially V-shaped cross section, the crystal orientation of the substrate is used while high-precision processing is possible. Therefore, the shape to be formed is restricted. In addition, since anisotropic etching requires an etching mask made of silicon oxide or the like, there is a problem in that the productivity can be reduced.
Furthermore, the coupling ratio of the optical path between the optical fiber fixed in the fixing groove of the manufactured optical fiber holding member and the optical element mounted on the holding member with the light reflection surface interposed therebetween is determined from the end face of the optical fiber to the optical element. Since it greatly depends on the distance to the light emitting / receiving surface, there is a problem that if there is a positional deviation in the optical path direction, transmission loss of the optical signal is caused.

  The present invention solves the problems described in the background art and provides an optical element substrate capable of accurately and reliably aligning an optical fiber used for optical communication, a light reflecting surface, and an optical element to be mounted. Is an issue.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the present invention has an optical fiber insertion groove and a light reflecting surface for converting an optical path, and an optical element substrate on which an optical element is mounted. It was conceived to apply.
That is, the optical element substrate of the present invention comprises a resin molded body having a front surface and a back surface on which the optical element is mounted, and a plurality of optical fiber insertion grooves opened on the surface of the molded body. A vertical fiber stop surface located at each end of the insertion groove and contacting the end face of the optical fiber to be inserted; at least adjacent to the fiber stop surface of the insertion groove for the optical fiber; and And a light reflecting surface that is inclined so as to spread toward the surface side.

  Since the optical element substrate is a resin molded body that can be collectively manufactured by an injection mold, it is highly productive and inexpensive, and is equivalent to an optical fiber holding member obtained by anisotropically etching a conventional crystal substrate. Since the position and shape accuracy can be made high, and there is no limitation due to the crystal orientation, the degree of freedom regarding the shape and the overall arrangement becomes very high. Furthermore, since the fiber stop surface is located at one end of each insertion groove, the optical fiber can be mounted at a predetermined position simply by inserting the optical fiber into the insertion groove and abutting the end surface against the stop surface. Accurate and easy. For this reason, the transmission loss of an optical signal can be further reduced as compared with a conventional optical fiber holding member obtained by anisotropically etching a crystal substrate. Therefore, the optical fiber, the light reflection surface, and the optical element can be accurately and reliably aligned, and an optical element substrate having such performance can be provided at low cost.

In addition, a thermosetting resin or a thermoplastic resin is used for the resin of the molded body.
Examples of the thermosetting resin include epoxy resins (cresol novolac type, phenol novolac type, bisphenol type, biphenyl type, gincopentadiene type, naphthalene type, etc.) and phenolic resins.
On the other hand, the thermoplastic resin includes polystyrene, polyamide, polyacetal, polycarbonate, polybutylene / terephthalate, polyethylene / terephthalate, polyphenylene / ether, polyethersulfone / polysulfone, polyether / etherketone. , Polyphenylene sulfide, polymethylpentene, polytetrafluoroethylene, polycyclohexylenedimethyl terephthalate resin, liquid crystal polymer, and the like.
Furthermore, the addition of an inorganic filler such as silica that suppresses the thermal expansion coefficient to each resin material is also included.
Further, the light reflecting surface may be in the form of an inclination angle of 45 degrees, an inclination angle of 60 degrees or 30 degrees, and an inclination angle between these, for example, with respect to the surface.
Furthermore, the insertion groove for the fiber has a substantially V-shaped cross-section formed of a pair of symmetrical inclined surfaces (for example, the bottom angle is 60 degrees), a pair of symmetrical inclined surfaces, and a flat surface that is horizontal to these bottom portions. And a generally U-shaped configuration with

Further, the present invention includes an optical element substrate in which the light reflecting surface is a part of a reflecting groove formed on the surface at a right angle in a plan view with respect to the optical fiber insertion groove. .
According to this, the end surface of the some optical fiber inserted for every some insertion groove | channel, the some optical element which has a light receiving / emitting surface corresponding to these, or the single optical element which has a some light receiving / emitting surface, On the other hand, it is possible to reliably form a reflecting surface in which the optical path direction is not displaced. For this reason, transmission loss can be further reduced.
The reflection groove has a substantially V-shaped cross section (for example, an angle of the bottom portion of 90 degrees) composed of a light reflection surface having an inclination angle of 45 degrees with respect to the surface and an inclined surface symmetrical to the light reflection surface. This includes a substantially letter-shaped cross section composed of a light reflection surface and a vertical surface with an inclination angle of 45 to 60 degrees.

Further, according to the present invention, the bottom of the insertion groove for the optical fiber is located on the back surface side with respect to the bottom of the reflection groove, and the height difference between the minimum parts is at one end of the insertion groove. An optical element substrate on which the fiber stop surface of the corresponding height is located is also included.
According to this, the bottom of the optical fiber insertion groove is located on the back side of the bottom of the reflection groove, and a vertical fiber stop surface corresponding to the difference (height difference) is used for the fiber. Is formed at one end of each insertion groove. For this reason, the optical fiber is inserted into each insertion groove, and the end face thereof is merely abutted against the fiber stop surface, and the optical path direction is not displaced between the reflecting surface and the light receiving / emitting surface of the optical element. It becomes possible to arrange reliably. Therefore, transmission loss can be reduced more easily.

In addition, in the present invention, between the surface and the side surface of the molded body located on the opposite side to the insertion groove for the optical fiber with the light reflection surface or the reflection groove including the same interposed therebetween, and the side surface A chamfered inclined surface is formed on at least one of the surface and the back surface, and a plurality of side surface wirings are formed across the surface and side surfaces of the molded body including the inclined surface, or the front surface, side surface, and back surface. An optical element substrate is also included.
According to this, since the plurality of side surface wirings include a portion inclined between the surface and the side surface of the molded body, it is possible to suppress or reduce return loss in the electrical signal converted by the optical element, and Conduction can be established between the substrate and the like. Alternatively, it is possible to send an external electric signal to the optical element while suppressing or reducing the return loss. Therefore, the electrical signal converted by the optical element and the electrical signal from the outside can be accurately transmitted.

Note that an electronic component (for example, an IC) for controlling electrical characteristics or the like is formed on the surface of the molded body between the optical element mounted on the surface of the molded body and the plurality of side wirings above the light reflecting surface. Chip) and the like are mounted.
The plurality of side surface wirings and the surface wiring that conducts between the optical element and the electronic component mounted on the surface of the molded body are set in advance at predetermined positions on the inner surface of the mold when the molded body is injection molded. By doing so, the molded body having the insertion groove, the fiber stop surface, and the light reflecting surface can be molded, and at the same time, the molded body can be disposed on the side surface or the surface of the molded body.

In the following, the best mode for carrying out the present invention will be described.
FIG. 1 is a perspective view showing an optical element substrate 1 according to an embodiment of the present invention, and FIG. 2 is a side view thereof. The optical element substrate 1 is mainly composed of, for example, an integrally molded body s made of an epoxy resin, and as shown in FIGS. 1 and 2, the entire surface having a front surface 2 and a back surface 3 has a substantially plate shape. Yes. The surface 2 of the molded body s is rectangular in plan view, and is divided into two surfaces 2a and 2b with a reflection groove 6 perpendicular to the longitudinal direction of the surface 2 interposed therebetween.
In FIG. 1 and FIG. 2, four (a plurality of) optical fiber insertion grooves 10 having a substantially V-shaped cross section formed in an opening on the surface 2 b are formed in parallel on the surface 2 b on the right side. The insertion groove 10 includes a pair of inclined surfaces 11 inclined symmetrically by 60 degrees with respect to the surface 2b. In addition, a support portion 5 for a fiber whose upper surface is substantially the same height as the lowest portion of each insertion groove 10 extends on the outer side (right side) of the surface 2b including the four insertion grooves 10.

  As shown in FIGS. 1 and 2, an inverted triangular fiber stop surface 12 standing vertically from the lowest part of the pair of inclined surfaces 11 is located at one end (back end) of each of the four rows of insertion grooves 10. ing. The reflection groove 6 includes a light reflecting surface 8 and an inclined surface 7 that are symmetrically inclined so as to spread toward the surfaces 2a and 2b. The lowest part of the reflection groove 6 is higher than the lowest part of the four insertion grooves 10. Therefore, the fiber stop surface 12 having a height corresponding to the difference in height is formed between the lowest part of the reflection groove 6 and the lowest part of each insertion groove 10. Furthermore, the upper half of one end of each insertion groove 10 is opened on the inclined surface 7 of the reflection groove 6.

  1 and 2, a plurality of surface wirings 14 are formed along the light reflecting surface 8 of the reflecting groove 6 on the left surface 2a. An optical element 24 to be described later is mounted above the surface wiring 14 and above the light reflecting surface 8 of the reflecting groove 6. A chamfered inclined surface c is formed between the surface 2 a and the side surface (end surface in the longitudinal direction of the surface 2) 4 and between the side surface 4 and the back surface 3. A plurality of side surface wirings 15 are formed in parallel and vertically on the side surface 4 across these. The side wiring 15 includes wiring portions 16 to 19 along the inclined surfaces c and c, the side surface 4, and the back surface 3. Note that an IC chip (electronic component) that is electrically connected to the surface 2a of the molded body s located between the plurality of side surface wirings 15 and the plurality of surface wirings 14 is mounted.

The optical element substrate 1 made of the molded body s having the shape (structure) as described above and having the surface wiring 14 and the side wiring 15 is manufactured as follows.
A convex shape corresponding to the reflection groove 6, the fiber insertion groove 10, and the fiber stop surface 12, a flat surface corresponding to the surfaces 2a and 2b, a side surface corresponding to the side surface 4 and the inclined surface c, etc. A lower mold having an inner surface including the upper mold and an upper mold having an inner surface including a flat surface corresponding to the back surface 3 are manufactured by mold processing. A shallow concave portion that accommodates the side wiring 15 including the surface wiring 14 and the wiring portion 16 is formed in a portion corresponding to the surface 2 a on the flat surface of the lower mold. In addition, shallow recesses for accommodating the wiring portions 17 and 18 of the side wiring 15 are formed on the inner surfaces of the lower mold and the upper mold. Further, a shallow concave portion for accommodating the wiring portion 19 of the side wiring 15 is formed in a portion corresponding to the back surface 3 on the flat surface of the upper mold.
Next, after storing the surface wiring 14 and the side wiring 15 made of a copper alloy thin plate (copper foil) in each recess of the lower mold, the upper mold is set on the surface wiring 14 and the mold is closed. In this state, the epoxy resin melted from the gate between the upper and lower molds is injection-molded into the mold.
The surface wiring 1 and the side wiring 15 may be formed at predetermined positions by performing thin film processing including patterning and etching on the molded body s taken out from the mold.
As a result, it is possible to obtain the optical element substrate 1 made of the molded body s having the shape shown in FIGS. 1 and 2 and having the surface wiring 14 and the side wiring 15.

3 and 4 show a state in which the optical fiber 20 is inserted into the insertion groove 10 of the optical element substrate 1. The optical fiber 20 is a glass wire made of quartz glass, and includes a core 22 having a high refractive index along the central portion and a clad 21 having a low refractive index surrounding the periphery of the optical fiber 20. Transmit while reflecting along the inner axial direction.
As shown by the arrows in FIGS. 3 and 4, the optical fiber 20 is inserted along the axial direction from the support portion 5 side for each insertion groove 10 of the optical element substrate 1. The outer diameter of the optical fiber 20 is substantially equal to the width of the intermediate position between the pair of inclined surfaces 11 and 11 in the insertion groove 10 and is substantially the same as or slightly smaller in depth than the insertion groove 10.
As shown in FIG. 5, the tip surface of the optical fiber 20 cut in advance at an angle orthogonal to the axial direction is such that the lower portion of the clad 21 abuts against the fiber stop surface 12 positioned at one end (back end) of the insertion groove 10. And stop. At this time, the core 22 at the distal end surface is located immediately above the fiber stop surface 12 and reaches the position near the center of the reflection groove 6 from the inclined surface 7. In this state, an adhesive (not shown) is applied between the clad 21 of the optical fiber 20 and the inclined surface 11 of the insertion groove 10 to fix the position of the optical fiber 20.

As illustrated in FIG. 5, the four optical fibers 20 are positioned such that the lower end of the tip surface is in surface contact with the fiber stop surface 12 of each insertion groove 10, and the tip is located near the center of the reflection groove 6. The core 22 of the surface faces the light reflecting surface 8 while being closest.
Next, as shown in FIG. 6, the optical element 24 is mounted via a brazing material (not shown) across the plurality of pads 23 at a position near the reflection groove 6 on each surface wiring 14 of the surface 2 a. The light emitting / receiving section (not shown) exposed on the bottom surface of the optical element 24 is located immediately above the reflecting surface 8. For this reason, as shown by the arrows in FIG. 6, the optical signal transmitted through the core 22 of the optical fiber 20 is reflected at a right angle by the reflecting surface 8 and rises vertically. Enter 24. The direction of the optical path is less likely to be misaligned by the four optical fibers 20 and the reflecting surfaces 8 that are accurately positioned on the fiber stop surface 12 for each insertion groove 10.
The optical element 24 is a substantially rectangular parallelepiped having a rectangular shape in a plan view along the longitudinal direction of the reflection groove 6, and four (a plurality) of optical / electrical conversion elements are incorporated therein.

  As shown in FIG. 6, an IC chip (electronic component) 26 is mounted on the surface 2a between the surface wiring 14 and the side wiring 15 via a brazing material or an epoxy resin. The IC chip 26 is connected to the surface wiring 14 and the side wiring 15 via bonding wires w (or flip chip mounting). The IC chip 26 performs control such as increasing the electric signal converted by the optical element 24 to a predetermined voltage and outputs the electric signal to the outside through the side wiring 15 and converts the electric signal transmitted from the outside into an optical signal. The electric characteristics are easily controlled.

That is, the optical signals transmitted from the four optical fibers 20 are reflected by the light reflecting surface 8 at a right angle, converted into an electric signal by the optical element 24, and increased to a predetermined voltage in the IC chip 26 through the surface wiring 14. Is output to the outside through the side wiring 15. On the other hand, the electrical signal transmitted from the outside through the side wiring 15 is adjusted to the required electrical characteristics in the IC chip 26, sent to the optical element 24 through the surface wiring 14, and then vertically downward from the light emitting / receiving section. After being reflected in the horizontal direction perpendicular to the light reflecting surface 8, the light is transmitted through the core 22 of the optical fiber 20 that is closest.
As shown in FIG. 1, the surface wirings 14 and 15 correspond to the four optical fibers 20, respectively, so that the total number is eight.

FIG. 7 is a side view showing an optical element substrate 1a of a different form.
The optical element substrate 1a is different from the optical element substrate 1 in a reflection groove 6a. As shown in FIG. 7, the reflection groove 6a is located on the surfaces 2a and 2b of the molded body s, but has the light reflection surface 8 inclined at 45 degrees toward the surface 2a, whereas The vertical surface 9 is on the 2b side. That is, the reflection groove 6a has a substantially letter shape in a side view, and the upper portions of the four fiber insertion grooves 10 are opened on the vertical surface 9, and the same reverse as described above is provided directly below these openings. A vertical fiber stop surface 12 presenting a triangle is located.
As shown in FIG. 8, when the optical fibers 20 are inserted and fixed in the same manner as described above for each of the insertion grooves 10, and the front end surfaces of the optical fibers 20 abut against the fiber stop surface 12 and come into surface contact, the cores 22 of those front end surfaces The reflecting groove 6a is flush with the vertical surface 9 and is closest to the adjacent light reflecting surface 8.

As shown in FIG. 8, in the optical element substrate 1a, the optical element 24 is mounted above the surface wiring 14, and the IC chip 26 mounted on the surface 2a is bonded to the bonding wire w (or flip chip mounting) as described above. To the surface wiring 14 and the side wiring 15.
As a result, as indicated by an arrow in FIG. 8, the optical signal emitted from the tip surface of the optical fiber 20 is reflected at a right angle by the light reflecting surface 8, converted into an electrical signal by the optical element 24, and the surface wiring 14. Then, the voltage is raised to a predetermined voltage in the IC chip 26 and then output to the outside through the side wiring 15. On the other hand, the electrical signal transmitted from the outside through the side wiring 15 is adjusted in electrical characteristics by the IC chip 26, sent to the optical element 24 through the surface wiring 14, and then emitted vertically from the light emitting portion to reflect light. After being reflected by the surface 8, it is transmitted through the core 22 of the optical fiber 20 that is closest.

FIG. 9 is a perspective view showing an optical element substrate 1b of still another form.
The optical element substrate 1b is different from the optical element substrates 1 and 1a in an optical fiber insertion groove 10b. The insertion groove 10b has a substantially U-shaped cross section having the same inclined surfaces 11 and 11 as described above and a horizontal flat surface 11b between the bottoms thereof. For this reason, a substantially inverted trapezoidal vertical fiber stop surface 12 is positioned at the end of the insertion groove 10b on the reflection groove 6 side.
As shown in FIG. 9, the outer diameter of the optical fiber 20 is substantially the same as the width of the intermediate position between the inclined surfaces 11 and 11 of the insertion groove 10b, and is also substantially the same as the depth of the horizontal flat surface 11b. . In addition, the core 22 exposed to the front end surface of each optical fiber 20 is exposed to the inside of the reflection groove 6 (6a) from one end of the insertion groove 10b opened in the inclined surface 7 (vertical surface 9) of the reflection groove 6 (6a). And is closest to the light reflecting surface 8.
Also by the optical element substrate 1b as described above, the optical signal emitted from the tip surface of the optical fiber 20 is reflected by the light reflecting surface 8, converted into an electrical signal by the optical element 24, and transmitted from the outside in the same manner as described above. The electrical signal adjusted by the IC chip 26 is converted into an optical signal by the optical element 24, reflected by the light reflecting surface 8, and then transmitted into the adjacent optical fiber 20.

  According to the optical element substrates 1, 1 a and 1 b as described above, a plurality (four) of optical fiber insertion grooves 10 and 10 b are formed on the surface 2 b of the resin molded body s. A vertical fiber stop surface 12 is positioned at one end, and the one end is open to the reflection grooves 6 and 6a orthogonal to the insertion grooves 10 and 10b. For this reason, when the optical fiber 20 is inserted into the insertion grooves 10 and 10b from the support portion 5 side, the lower portion of the clad 21 at the distal end surface comes into surface contact with the fiber stop surface 12 and stops at this position. The core 22 exposed to the surface is exposed to the inside of the reflection grooves 6 and 6 a and is closest to the light reflection surface 8. Thus, the optical path is not easily displaced from the optical element 24 mounted above the light reflecting surface 8, and an accurate optical path can be formed, so that transmission loss can be reduced.

Further, since the side wiring 15 includes wiring portions 16 and 18 that follow the upper and lower inclined surfaces c and c of the side surface 4, it is possible to reduce return loss and improve electrical signal conduction. Moreover, the molded body s having the reflection grooves 6 and 6a, the insertion grooves 10 and 10b, the fiber stop surface 12, and the like has high shape and dimensional accuracy by injection molding with epoxy resin or the like, and is more efficient than the conventional crystal substrate. It can be manufactured well at low cost.
Therefore, according to the optical element substrates 1, 1 a, 1 b, the optical fiber 20, the light reflecting surface 8, and the optical element 24 to be mounted can be accurately and reliably aligned, the transmission loss can be reduced, and the cost can be reduced. It can also be produced and provided.

FIG. 10 is a perspective view showing an electrical connector 30 using the optical element substrate 1 (1a, 1b). The electrical connector 30 is made of resin or ceramic, and has an overall plate-like connector main body 31 having a front surface 32 and a rear surface 33, and a plurality of channels (channels) with the pitch between adjacent wires widened on the front surface 32. The number of the connection wirings 34 is one pair (eight) with respect to the number of optical fibers. In FIG. 10, the pitch between the connection wires 34 is narrow on the center side of the surface 32 of the connector main body 31, and this pitch is the same as the pitch between the side wires 15 in the optical element substrate 1 (1a, 1b). Is set to
In advance, the optical fiber 20 is inserted and fixed in each of the insertion grooves 10 and 10b of the optical element substrate 1 (1a and 1b), and the optical element 24 and the IC chip 26 are mounted on the surface 2a in the same manner as described above. 14, the IC chip 26 and the side wiring 15 are connected via a flip chip or the wire bonding w.

Next, the side wiring located on the back surface 3 side of the optical element substrate 1 (1a, 1b) is placed directly above each connection wiring 34 located on the center side of the front surface 32 of the connector body 31 via a brazing material (not shown). The wiring part 19 for every 15 is mounted, and it connects by heating (reflow). An underfill material (not shown) is filled and solidified in a gap between the front surface 32 of the connector main body 31 surrounding the brazing portion and the back surface 3 of the optical element substrate 1 (1a, 1b), thereby solidifying both. Glue. As a result, an electrical connector 30 as shown in FIG. 10 is obtained.
According to the electrical connector 30 as described above, the end surfaces on the side of the connection wires 34, 34 having a large pitch in the connector main body 31 are inserted into external terminals in an electronic / electric device (not shown), and the other connection electrode is connected to each connection wire 34. By making surface contact with the optical signal, the optical signal from the optical fiber 20 can be converted into an electric signal with a small transmission loss and transmitted to an electronic / electrical device. At the same time, an electrical signal output from such an electronic / electrical device can be converted into an optical signal with little transmission loss and transmitted to another electronic device or the like located away from the optical fiber 20.

The present invention is not limited to the embodiments described above.
The molded body constituting the optical element substrate may be made of a thermosetting resin other than the epoxy resin or a thermoplastic resin such as a polyamide resin.
Further, the optical fiber insertion groove may have a substantially concave cross section formed by a pair of vertical side walls and a bottom surface between these bottom sides. In this case, a substantially rectangular fiber stop surface is formed on the bottom side at one end of the insertion groove.
Furthermore, the light reflection surface (8) of the light reflection groove may have an arbitrary inclination within a range of 30 degrees to 60 degrees with respect to the surface (2a) of the optical element substrate.
In addition, the upper surface of the support portion (5) of the optical element substrate is positioned lower than the lowest portion of the optical fiber insertion groove (10, 10b) on the back surface (3) side. The lowest part of the protective cover covering the outer periphery of the clad (21) may be supported. Or it is also possible to set it as the board | substrate for optical elements provided with the molded object (s) which abbreviate | omitted the said support part (5).

The perspective view which shows the board | substrate for optical elements which is one form of this invention. The side view which shows the said board | substrate for optical elements. The side view which shows the state which inserts an optical fiber in the said board | substrate for optical elements. The perspective view which shows the outline of the state which inserts the said optical fiber. The side view which shows the said board | substrate for optical elements in which the optical fiber was inserted. Furthermore, the side view which shows the said board | substrate for optical elements in which the optical element etc. were mounted. The side view which shows the board | substrate for optical elements of a different form. The side view which shows the said board | substrate for optical elements in which the optical fiber was inserted. Furthermore, the perspective view which shows the board | substrate for optical elements of a different form. The perspective view which shows the electrical connector using the said board | substrate for optical elements.

Explanation of symbols

1, 1 a, 1 b ... optical element substrate 2, 2 a, 2 b ... front face 3 ............... back face 4 ............... side face 6, 6 a .... reflective groove 8 ......... …… Light reflecting surface 10, 10b …… Insertion groove 12 ……………… Fiber stop surface 15 ……………… Side wiring 20 ……………… Optical fiber s …………………… Molded body c ………………… Inclined surface

Claims (4)

It consists of a molded body made of resin having a front surface and a back surface on which the optical element is mounted,
Insert grooves for a plurality of optical fibers formed on the surface of the molded body,
A vertical fiber stop surface located at each end of the plurality of insertion grooves and in contact with the end face of the optical fiber to be inserted;
A light reflecting surface that is adjacent to at least the fiber stop surface of the insertion groove for the optical fiber and is inclined so as to spread toward the surface side of the molded body,
An optical element substrate characterized by the above. The light reflection surface is a part of a reflection groove formed on the surface at a right angle in a plan view with respect to the insertion groove for the optical fiber.
The optical element substrate according to claim 1. The bottom of the insertion groove for the optical fiber is located on the back side of the bottom of the reflection groove, and the fiber having a height corresponding to the height difference between the minimum portions at one end of the insertion groove The stop surface is located,
The optical element substrate according to claim 2. At least one of the surface and the side surface of the molded body located on the opposite side of the optical fiber insertion groove with the light reflection surface or the reflection groove including the light reflection surface interposed therebetween, and between the side surface and the back surface. A chamfered inclined surface is formed on the surface and side surfaces of the molded body including the inclined surface, or a plurality of side surface wirings extending over the front surface, side surface, and back surface are formed.
The optical element substrate according to claim 1, wherein the substrate is an optical element substrate.

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