JP2009086539A - Optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module for reducing misalignment between an optical element and a substrate having an optical waveguide. <P>SOLUTION: This optical module is provided with a composite substrate including an optical waveguide part and a plurality of wiring parts, an optical element substrate having a plurality of optical element arrays having a plurality of light emitting parts or a plurality of photoreception parts and a plurality of connection terminals, interposed between a first line defined by connecting the centers of two of the plurality of connection terminals, and a second line parallel to the first line and defined by connecting the centers of the other two connection terminals different from the two terminals, and arranged symmetrically with respect to a symmetry axis having the same distance from the first line and the second line, and a conductive solder part for coupling optically the optical waveguide to the plurality of light emitting parts or the plurality of photoreception parts by connecting the plurality of wiring parts and the plurality of connection terminals. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical module.

  Conventionally, as a method of connecting a module in which a light receiving element, a light emitting element, and a signal processing IC are mounted on a supporting substrate to a predetermined substrate, a method using a self-alignment effect by solder reflow is known.

  As an optical element mounting structure formed by using such a self-alignment effect, solder electrodes are provided at least at the four corners around the optical element module and at other positions, and solder at the four corners around the optical element module. An optical element mounting structure in which the size of an electrode is larger than the size of a solder electrode at another position is known (see, for example, Patent Document 1).

According to the optical element mounting structure described in Patent Document 1, it is possible to accurately position the optical element at a predetermined position on the substrate by using the self-alignment effect due to the surface tension when the solder melts. it can.
JP 2003-243757 A

  An object of the present invention is to provide an optical module capable of reducing a positional shift between an optical element and a substrate having an optical waveguide.

  One embodiment of the present invention provides the following optical module to achieve the above object.

(1) It has a fusion substrate including an optical waveguide part and a plurality of wiring parts, a plurality of light emitting parts or a plurality of light receiving parts, and a plurality of connection terminals, and the center of two connection terminals among the plurality of connection terminals. Sandwiched between a first line defined by connecting and a second line defined by connecting the centers of two other connection terminals that are parallel to the first line and different from the two connection terminals; Connecting an optical element substrate having a plurality of optical element arrays arranged symmetrically with respect to a symmetry axis having the same distance from the first line and the second line, a plurality of wiring portions, and a plurality of connection terminals; Thus, an optical module comprising a conductive solder portion that optically couples the optical waveguide portion and the plurality of light emitting portions or the plurality of light receiving portions.

(2) The optical element substrate has the first optical element array and the second optical element array symmetrically with respect to the symmetry axis, and the light emitting unit or the light receiving unit located closest to the symmetry axis of the first optical element array. Between the plurality of light emitting units or the plurality of light receiving units of the first optical element array is a distance between the light emitting unit and the light receiving unit located closest to the symmetry axis of the second optical element array. The optical module according to (1), which is a distance defined by an integer multiple or an integer multiple of a pitch between a plurality of light receiving portions or a plurality of light emitting portions of the second optical element array.

(3) The optical module according to (2), wherein the plurality of optical element arrays include a surface emitting laser array and a photodiode array.

(4) The optical module according to any one of (1) to (3), wherein the solder portion includes a resin core portion having a resin and a conductive layer formed to cover the resin core portion.

  In another aspect of the present invention, the following optical module is provided to achieve the above object.

(5) An optical element substrate having an optical waveguide portion and a plurality of wiring portions, a plurality of connection terminals, and a plurality of optical element arrays including a plurality of light emitting portions or a plurality of light receiving portions, and a resin And a plurality of light emitting portions by connecting a plurality of wiring portions and a plurality of connection terminals. Or an optical module provided with the solder part which couple | bonds a some light-receiving part optically.

  According to the optical module of the first aspect, it is possible to reduce the positional deviation of the optical element array with respect to the optical waveguide portion caused by the difference between the linear expansion coefficient of the fusion substrate and the linear expansion coefficient of the optical element substrate.

  According to the optical module of the second aspect, when a plurality of optical element arrays are used, an optical module with high versatility can be provided.

  According to the optical module of the third aspect, it is possible to increase the surface density of the light emitting unit and to perform optical communication in the minimum region.

  According to the optical module of the fourth and fifth aspects, the positioning accuracy between the optical element substrate and the fusion substrate can be improved, and the linear expansion coefficient of the fusion substrate and the linear expansion of the optical element substrate can be improved. The stress caused by the difference from the coefficient can be relaxed.

[First Embodiment]
FIG. 1 shows an optical module according to a first embodiment of the present invention, and FIG. 1A is a cross-sectional view taken along the line AA of the figure showing the back surface of the optical element substrate shown in FIG.

(Configuration of optical module 1)
The optical module 1 according to the first embodiment includes a light emitting element array 100 as an optical element array that emits light of a predetermined wavelength, and a light receiving element array 105 as an optical element array that has light receiving sensitivity to light in a predetermined wavelength range. And an integrated substrate 20 on which the optical element substrate 10 is mounted via a plurality of solder balls 30 including a resin core portion 300 therein.

(Configuration of optical element substrate 10)
Specifically, the optical element substrate 10 includes a support substrate 140 on which an electronic component such as a large-scale integrated circuit (LSI) is mounted, and a plurality of optical element substrates 10 provided through the support substrate 140 at predetermined positions along the outer edge of the support substrate 140. Of the plurality of outer terminals 112 and a plurality of inner terminals as a plurality of connection terminals provided through the support substrate 140 at positions separated by a predetermined distance toward the opposite side of the outer edge of the support substrate 140 of the plurality of outer terminals 112. 110.

  Further, the inner terminal shaft 51a as a first line connecting the centers of at least two inner terminals 110 and at least two other inner terminals 110 different from the at least two inner terminals 110 forming the inner terminal shaft 51a. An inner terminal shaft 51b is defined as a second line formed by connecting the centers and parallel to the inner terminal shaft 51a. In this case, the optical element substrate 10 is symmetrically supported with respect to the axis of equal distance from each of the inner terminal shaft 51a and the inner terminal shaft 51b, that is, the line symmetry axis 50 as the symmetry axis in FIG. The light emitting element array 100 and the light receiving element array 105 are provided on the surface 140.

  Furthermore, the optical element substrate 10 has a plurality of terminals 115 formed on the surface opposite to the surface on which the light emitting element array 100 and the light receiving element array 105 are provided. The optical element substrate 10 is mounted with the signal processing IC 120 via the solder 117 mainly formed from an alloy material such as Au—Sn provided on each of the plurality of terminals 115. The signal processing IC 120 is sealed by a sealing portion 130 mainly formed from a resin material.

(Support substrate 140)
The support substrate 140 is formed in a substantially square shape when viewed from above. The support substrate 140 is mainly formed from an organic material or an inorganic material. For example, the support substrate 140 is formed of a composite material of glass fibers and an epoxy resin, that is, an insulating material such as a glass epoxy resin. For example, the support substrate 140 is made of Frame Regentant Type 4 (FR-4).

  The support substrate 140 has wiring portions formed of a metal material such as copper, gold, or aluminum on the surface on which the signal processing IC 120 is mounted and the surface on which the light emitting element array 100 and the light receiving element array 105 are mounted. Have. For example, a plurality of terminals 116 as wiring portions are formed on the surface of the support substrate 140 on which the light emitting element array 100 and the light receiving element array 105 are mounted.

  The plurality of terminals 116 and the light emitting element array 100 are electrically connected via wires 150. Similarly, the plurality of terminals 116 and the light receiving element array 105 are electrically connected through wires 150. The plurality of terminals 116 are electrically connected to terminals 115 provided on the surface on which the signal processing IC 120 is formed through through holes (not shown) formed in the support substrate 140. Further, the plurality of terminals 115 are electrically connected to a power supply wiring portion (not shown) formed in advance on the surface of the support substrate 140 on which the signal processing IC 120 is mounted.

  A ground is previously formed on the surface of the support substrate 140 on which the light emitting element array 100 is mounted, and the light emitting element array 100 and the light receiving element array 105 are electrically connected to the ground. For example, the light emitting element array 100 and the light receiving element array 105 are fixed at predetermined positions on the support substrate 140 using a conductive adhesive such as Ag paste.

The support substrate 140 is an inorganic material having a thermal conductivity of a predetermined value or more, specifically, AlN for the purpose of efficiently radiating heat generated from the light emitting element array 100 and / or the like and / or improving transmission characteristics. It can also be formed from a ceramic material such as SiC or a semiconductor material such as Si having an insulating film such as SiO _{2 on the} surface.

(Light Emitting Element Array 100)
The light emitting element array 100 is an array of light emitting elements (surface emitting optical elements) including a plurality of surface emitting light emitting diodes or a plurality of surface emitting semiconductor laser diodes. In the present embodiment, the light emitting element as the light emitting unit is a surface emitting semiconductor laser diode. That is, the light emitting element array 100 has a structure in which a plurality of light emitting elements are arranged along a predetermined direction. For example, as illustrated in FIG. 1B, the light emitting element array 100 includes a plurality of light emitting elements at a predetermined pitch. The light emitting element array 100 includes a light emitting region, for example, a light emitting region 101, for each of the plurality of light emitting elements. In addition, each pitch between the plurality of light emitting regions is 250 μm as an example. The light emitting element array 100 can also be formed by setting each pitch between the plurality of light emitting regions to an integral multiple of 250 μm, for example, 500 μm, 750 μm, or the like.

  Specifically, a vertical cavity surface emitting laser (VCSEL) is used as the plurality of light emitting elements constituting the light emitting element array 100 according to the present embodiment. A plurality of terminals 116 provided on the support substrate 140 and supplying power to the plurality of VCSELs constituting the light emitting element array 100 are formed on the through holes formed in the support substrate 140 and the surface of the support substrate 140, respectively. The terminal 115 is electrically connected through a circuit pattern. Thereby, the signal processing IC 120 having a function as a driver IC for driving the light emitting element array 100 and the terminal 116 are electrically connected.

  As an example, the VCSEL as the light-emitting element according to this embodiment has a threshold current of 1 mA, and emits light in a range of 840 nm to 860 nm, for example, 850 nm at a forward voltage of 1.6 V to 2.2 V. Has a wavelength. That is, the light emitting element has an emission wavelength in the near infrared region (wavelength: 700 nm to 1000 nm). In addition, the response speed of the light emitting element according to this embodiment is 2.5 Gbps.

  The VCSEL constituting the light emitting element array 100 according to the present embodiment has a III-V group compound semiconductor stacked structure. For example, a VCSEL has an n-type DBR (Distributed Bragg Reflector) layer as an n-type lower reflector layer, an active layer, a current confinement layer, and a p-type DBR layer as a p-type upper reflector layer on an n-type GaAs substrate. The p-type contact layer is formed in this order.

Here, for the n-type DBR layer, for example, n-type Al _x Ga _1-x As (0 <x <1) can be used. For the p-type DBR layer, for example, p-type Al _x Ga _1-x As (0 <x <1) can be used. The active layer can be composed of an i-GaAs bulk layer, a single quantum well layer, or a multiple quantum well layer. The current confinement layer can be formed, for example, by injecting protons into a predetermined region of the p-type DBR layer to form a high resistance region. Further, the p-type contact layer can be formed of, for example, GaAs doped with Zn as a p-type dopant having a predetermined concentration.

  An n-type electrode is formed on the opposite side of the surface of the n-type GaAs substrate where the n-type DBR layer is formed, and a p-type electrode is formed on the p-type contact layer. Here, the p-type electrode has a light emitting region as an opening immediately above the light emitting region of the active layer. The light emitting region is formed in a substantially circular shape when viewed from above, and has a diameter of 5 μm to 10 μm. Then, light in the near infrared region is emitted from the light emitting region. Note that a VCSEL having a response speed of 10 Gbps may be used as the light emitting element.

(Light receiving element array 105)
The light receiving element array 105 includes, for example, a plurality of planar photodiodes as light receiving elements. That is, the light receiving element array 105 is a photodiode array. In the present embodiment, GaAs photodiodes that are excellent in high-speed response are used as a plurality of light receiving elements as light receiving portions constituting the light receiving element array 105. That is, as shown in FIG. 1B, the light receiving element array 105 has a plurality of light receiving elements at a predetermined pitch. The light receiving element array 105 has a light receiving region that receives light for each of the plurality of light receiving elements, for example, a light receiving region 106.

  PIN photodiodes are used as the plurality of photodiodes constituting the light receiving element array 105 according to the present embodiment. A plurality of terminals 116 that are provided on the support substrate 140 and supply power to each of the plurality of PIN photodiodes constituting the light receiving element array 105 are electrically connected to the terminals 115 through through holes formed in the support substrate 140. Connect. As a result, the signal processing IC 120 having a function as a receiver IC for driving the light receiving element array 105 and the terminal 116 are electrically connected.

  The PIN photodiode constituting the light receiving element array 105 according to the present embodiment has a III-V group compound semiconductor structure. For example, in a PIN photodiode, a p-type semiconductor layer (p layer), an intrinsic semiconductor layer (i layer), and an n-type semiconductor layer (n layer) are formed on a GaAs substrate, and the i layer is a p layer. It has a PIN structure formed between n layers. The PIN photodiode further includes a p-side electrode connected to the p layer and an n-side electrode formed in the n layer, and the n-side electrode has a light receiving region as an opening in a predetermined region. The PIN photodiode receives light in the light receiving region. Here, as an example, the PIN photodiode has a sensitivity of 0.2 (A / W) at a wavelength of 850 nm, and the diameter of the light receiving region is, for example, about 1 mm.

  The III-V compound semiconductor stacked structure forming the light emitting element array 100 and the light receiving element array 105 according to the present embodiment is, for example, metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy. It is formed by the method (Molecular Beam Epitaxy: MBE), the halide vapor phase epitaxy (Halide Vapor Phase Epitaxy: HVPE), or the like.

(Signal processing IC 120)
The signal processing IC 120 has a function of a driver IC as a drive circuit that drives the light emitting element array 100. Further, the signal processing IC 120 has a function of a receiver IC as an amplifier circuit that amplifies an electric signal photoelectrically converted by the light receiving element based on light received by the light receiving element of the light receiving element array 105.

(Sealing part 130)
The sealing part 130 is formed from a thermosetting molding material such as an epoxy resin, and protects the signal processing IC 120 from an environment such as light, heat, and humidity. The sealing portion 130 may be formed by using an epoxy resin as a main component and adding a filler such as silica to the epoxy resin.

(Configuration of the fusion substrate 20)
The fusion substrate 20 is provided on one surface of the optical waveguide layer 200 including a plurality of cores 202 as an optical waveguide part that propagates light in a predetermined wavelength range, and on a part of the cores 202. A surface of the first substrate in contact with the optical waveguide layer 200, the first substrate 210 including the opening 240 formed in the first substrate 210, the second substrate 212 provided on the surface opposite to the surface on which the first substrate 210 is provided. And a plurality of terminals 220 (for example, a terminal 220a, a terminal 220b, a terminal 220c, and a terminal 220d) serving as a wiring portion formed on the opposite surface.

  The first substrate 210 and the second substrate 212 included in the fusion substrate 20 are formed of an insulating material such as glass epoxy resin, for example. The first substrate 210 has a plurality of terminals such as a terminal 220a, a terminal 220b, a terminal 220c, and a terminal 220d formed of a conductive material such as copper, gold, and aluminum on the surface on which the optical element substrate 10 is mounted. Have

  As shown in FIG. 1A, the first substrate 210 includes a plurality of light emitting elements included in the light emitting element array 100 and a plurality of cores 202 included in the fusion substrate 20 at a position where the light emitting element array 100 is provided. Each has an opening 240 for optical coupling. Note that if the light coupling between the core 202 and the light emitting element included in the light emitting element array 100 is possible, the opening 240 is transparent to the wavelength of light emitted from the light emitting element included in the light emitting element array 100. Material may be filled. Similarly, as shown in FIG. 1A, the first substrate 210 includes a plurality of light receiving elements included in the light receiving element array 105 and a plurality of cores 202 included in the fusion substrate 20 at a position where the light receiving element array 105 is provided. And an opening 240 for optically coupling the two.

  The optical waveguide layer 200 according to the present embodiment has a core 202 and a clad formed around the core 202 and covering the core 202. And as an example, the optical waveguide layer 200 is formed with a thickness including the core 202 and the clad in the range of 100 to 200 μm.

(Solder ball 30)
The solder ball 30 as a solder part is formed to have a resin core part 300 as a central core mainly formed from a resin and a solder layer 305 as a conductive layer covering the resin core part 300. Specifically, the resin core part 300 is mainly formed from a thermosetting resin having a predetermined elasticity at a predetermined temperature. And the resin core part 300 is formed in a substantially spherical shape. As an example, the resin core part 300 is formed with a diameter in the range of 200 μm to 800 μm.

  The solder layer 305 is formed of an alloy material such as a Sn—Ag metal material, a Sn—Zn metal material, or a Sn—In metal material. As an example, the solder layer 305 is formed with a thickness in the range of 1 μm to 30 μm. The solder ball 30 can also be formed by providing a conductive metal such as Cu having a predetermined thickness between the resin core portion 300 and the solder layer 305.

(Details of arrangement of optical element array)
The light emitting element array 100 as the first optical element array and the light receiving element array 105 as the second optical element array are center lines (inner terminal axes) formed from the centers of the plurality of inner terminals 110 of the support substrate 140. ) With respect to the line symmetry axis 50 defined on the basis of ()). For example, as shown in FIG. 1B, a line (inner terminal shaft 51a) connecting the center of the inner terminal 110a and the center of the inner terminal 110b is connected to the center of the inner terminal 110c and the center of the inner terminal 110d. An ellipse (inner terminal shaft 51b) is defined. In this case, straight lines that are equidistant from the inner terminal shaft 51a and the inner terminal shaft 51b and that are parallel to the inner terminal shaft 51a and the inner terminal shaft 51b are the line symmetry axes 50, respectively.

  In the present embodiment, the support substrate 140 is symmetrical with respect to the line symmetry axis 50 defined by the inner terminal shaft 51a and the inner terminal shaft 51b, in other words, the line symmetry axis 50 defined by the plurality of inner terminals 110. The light emitting element array 100 and the light receiving element array 105 are mounted on the upper position. Specifically, the interval between the light emitting region 101 provided at the position closest to the line symmetry axis 50 and the light receiving region 106 provided at the position closest to the line symmetry axis 50 is between a plurality of light emitting elements of the light emitting element array 100. The light emitting element array 100 and the light receiving element array 105 are mounted at a position that is an integral multiple of the pitch between the plurality of light receiving elements of the light receiving element array 105.

  In this case, the light emitting element array 100 and the light receiving element array 105 are each fixed on the support substrate 140 so as to be mounted in the vicinity of the line symmetry axis 50. For example, in this embodiment, the pitch between the plurality of light emitting elements and the pitch between the plurality of light receiving elements are each 250 μm, and therefore, the distance between the light emitting region 101 and the light receiving region 106 is an integral multiple of 250 μm, The range is set so that the element array 100 and the light receiving element array 105 do not contact each other. As a result, the light emitting region 101 and the light receiving region 106 are arranged at positions symmetrical with respect to the line symmetry axis 50.

  FIG. 2A shows a cross section of the optical module according to the first embodiment of the present invention at room temperature, and FIG. 2B shows the optical module according to the first embodiment of the present invention. The cross section at the time of temperature rising is shown.

  As shown in FIG. 2A, the light from the plurality of light emitting elements included in the light emitting element array 100 of the optical element substrate 10 and the plurality of light receiving elements included in the light receiving element array 105 and the plurality of cores 202 included in the fusion substrate 20. The optical element substrate 10 is mounted on the fusion substrate 20 via a plurality of solder balls 30 at room temperature so that the axes are substantially coincident with each other. Then, the optical module 1 is manufactured by fixing the optical element substrate 10 on the fusion substrate 20 via the solder balls 30 through a predetermined reflow process.

  Here, since the solder ball 30 having the resin core portion 300 is used in the present embodiment, the distance between the optical element substrate 10 and the fusion substrate 20, that is, the distance in the Z-axis direction is maintained at a substantially constant distance. Can do. That is, in the present embodiment, by using the solder balls 30, the distance between the fusion substrate 20 and the optical element substrate 10 is kept within a predetermined range, and the optical element substrate 10 has a surface relative to the surface of the fusion substrate 20. The position can be determined. Thus, the fusion substrate 20 and the optical element substrate 10 are positioned so that the distances from the surface of the optical waveguide layer 200 of the fusion substrate 20 to the surfaces of the light emitting element array 100 and the light receiving element array 105 are substantially constant. can do.

  Here, the inner terminal shaft 51a defined from the center of the plurality of inner terminals 110 and the inner terminal defined from the center of the plurality of inner terminals 110 located on the opposite side via the line symmetry axis 50 of the inner terminal shaft 51a. Consider axis 51b. Depending on the difference between the linear expansion coefficient of the material constituting the support substrate 140 and the linear expansion coefficient of the material constituting the first substrate 210 of the fusion substrate 20, heat during reflow or driving of the light emitting element array 100 and the signal processing IC 120 Due to the heat of time, as shown in FIG. 2B, the inner terminal shaft 51a extends to the opposite side of the line symmetry axis 50 and shifts to the position of the inner terminal shaft 51c. Similarly, the inner terminal shaft 51b extends to the opposite side of the line symmetry axis 50 and shifts to the position of the inner terminal shaft 51d.

  However, in the present embodiment, since the light emitting element array 100 and the light receiving element array 105 are arranged in line symmetry near the line symmetry axis 50, the influence of the optical coupling misalignment is affected by the line symmetry axis 50. It is smaller than the position away from. That is, even when the temperature is raised from room temperature to a predetermined temperature, the displacement of the support substrate 140 in the vicinity of the line symmetry axis 50 with respect to the fusion substrate 20 due to the expansion of the support substrate 140 is caused by the inner terminal 110 of the support substrate 140. Small compared to the neighborhood. That is, the positional displacement of the light emitting element array 100 and the light receiving element array 105 with respect to the core 202 due to the difference between the linear expansion coefficient of the support substrate 140 and the first substrate 210 is reduced in the vicinity of the line symmetry axis 50. The

  In addition, since the solder ball 30 includes the resin core portion 300 having a predetermined elasticity, the stress applied to the solder ball 30 at the time of temperature rise is reduced, and the misalignment of the light emitting element array 100 and the light receiving element array 105 with respect to the core 202 is shifted. Reduced.

[Second Embodiment]
FIG. 3 shows an optical module according to a second embodiment of the present invention, wherein (a) is a cross-sectional view taken along the line BB in the figure showing the back surface of the optical element substrate shown in (c). b) is a sectional view taken along the line CC of FIG.

  In the optical module according to the second embodiment, the optical element substrate has two light emitting element arrays and two light receiving element arrays, and the fusion substrate 20 has cores corresponding to the two light emitting element arrays and the two light receiving element arrays. Except for this point, the optical module has substantially the same configuration as that of the optical module according to the second embodiment. Therefore, a detailed description is omitted except for differences.

(Configuration of the fusion substrate 20)
As illustrated in FIG. 3B, the optical waveguide layer 200 includes a core 202 and a clad 201 that is formed around the core 202 and covers the core 202. The core 202 is placed at a position of an opening 240 provided at a position corresponding to the light incident side end of the first substrate 210 and a position of the opening 240 provided at a position corresponding to the light emitting side end. It has a mirror section 250 including a mirror 252 as an incident-side optical path conversion section and an exit-side optical path conversion section provided at an inclination of 45 degrees with respect to the propagation direction of the propagating light.

  The mirrors 252 of the mirror unit 250 are respectively provided on the optical paths between the light emitting elements of the light emitting element array 100, the core 202, and the light receiving elements of the light receiving element array 105. The periphery of the mirror 252 is filled with a light transmissive resin 254 having a refractive index equivalent to that of the clad 201.

(Disposition of solder balls 30)
And in 2nd Embodiment, as shown in FIG.3 (c), the solder ball 30 which connects the fusion | melting board | substrate 20 and the optical element board | substrate 10 as an example, the direction where the core 202 is extended, ie, light It is provided only in a direction substantially parallel to the propagation direction. That is, the plurality of inner terminals 110 included in the optical element substrate 10 are provided only along two opposing sides of the four sides of the support substrate 140.

(Arrangement of light emitting element array 100 and light receiving element array 105)
The light emitting element array 100 a and the light receiving element array 105 a are arranged at positions symmetrical with respect to the line symmetry axis 50. Similarly, the light emitting element array 100b and the light receiving element array 105b are disposed at positions symmetrical with respect to the line symmetry axis 50. The light emitting element arrays 100a and 100b and the light receiving element arrays 105a and 105b are respectively arranged at positions separated from the line symmetry axis 50 by a predetermined distance. That is, the distance between the light emitting element array 100a and the light receiving element array 105a is such that the interval between the light emitting area 101a and the light receiving area 106a is an integral multiple of the pitch between the plurality of light emitting areas included in the light emitting element array 100a. It is prescribed.

  FIG. 4 shows a state of optical coupling between the light emitting element of the light emitting element array and the light receiving element of the light receiving element array and the core according to the second embodiment of the present invention.

  As an example, a fusion substrate 20 having a 12-channel core 202 will be described. The pitch between the light emitting region 101a present at the position closest to the light receiving element array 105a and the light receiving region 106a present at the position closest to the light emitting element array 100a is the pitch between the plurality of light emitting elements included in the light emitting element array 100a. It is set to an integral multiple of (P) (for example, three times the pitch).

  When the interval between the light emitting area 101a and the light receiving area 106a is three times the pitch, the core 202a corresponding to each light emitting element and the core 202c corresponding to each light receiving element become the core 202 used for optical communication. The core 202b, the core 202d, and the core 202e excluding these cores are unused cores.

[Third Embodiment]
FIG. 5 shows the back surface of the optical element substrate according to the third embodiment of the present invention.

  In the optical module according to the third embodiment, the optical element substrate has four light emitting element arrays and four light receiving element arrays, and the fusion substrate 20 has cores corresponding to the four light emitting element arrays and the four light receiving element arrays. Except for this point, the optical module has substantially the same configuration as that of the optical module according to the first embodiment. Therefore, a detailed description is omitted except for differences.

(Arrangement of each light emitting element array and each light receiving element array)
In the third embodiment, the plurality of light emitting element arrays and the plurality of light receiving element arrays are respectively arranged at positions that are symmetric with respect to the line symmetry axis. Specifically, the light emitting element array 100a and the light receiving element array 105a are positions that are symmetric with respect to the line symmetry axis 50a, and are disposed at predetermined positions from the line symmetry axis 50a. Similarly, the light emitting element array 100b and the light receiving element array 105b are arranged at positions that are symmetric with respect to the line symmetry axis 50a.

  Further, the light emitting element array 100c and the light receiving element array 105d are positions that are symmetric with respect to the line symmetry axis 50b perpendicular to the line symmetry axis 50a, and are disposed at predetermined positions from the line symmetry axis 50b. Similarly, the light receiving element array 105c and the light emitting element array 100d are arranged at positions that are symmetric with respect to the line symmetry axis 50b.

  While the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all the combinations of features described in the embodiments are essential for the means for solving the problems of the invention.

It is a figure which shows the optical module which concerns on the 1st Embodiment of this invention, (a) is sectional drawing in the AA part of the figure which shows the back surface of the optical element board | substrate shown in (b). (A) is sectional drawing at the time of normal temperature of the optical module which concerns on the 1st Embodiment of this invention, (b) is at the time of temperature rising of the optical module which concerns on the 1st Embodiment of this invention. It is sectional drawing. It is a figure which shows the optical module which concerns on the 2nd Embodiment of this invention, (a) is sectional drawing in the BB part of the figure which shows the back surface of the optical element board | substrate shown in (c), (b ) Is a cross-sectional view taken along the line CC of FIG. It is a figure which shows the mode of the optical coupling of the light emitting element of the light emitting element array which concerns on the 2nd Embodiment of this invention, the light receiving element of a light receiving element array, and a core. It is a figure which shows the back surface of the optical element substrate which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical module 10 Optical element board | substrate 20 Fusion board | substrate 30 Solder ball 50, 50a, 50b Axis of symmetry 51a, 51b, 51c, 51d Inner terminal axis 100, 100a, 100b, 100c, 100d Light emitting element array 101, 101a, 101b, 101c , 101d Light emitting area 105, 105a, 105b, 105c, 105d Light receiving element array 106, 106a, 106b, 106c, 106d Light receiving area 110, 110a, 110b, 110c, 110d Inner terminal 112 Outer terminal 115 Terminal 116, 116a, 116b, 116c 116d terminal 117 solder 120 signal processing IC
130 Sealing portion 140 Support substrate 150 Wire 200 Optical waveguide layer 201 Clad 202, 202a, 202b, 202c, 202d, 202e Core 210 First substrate 212 Second substrate 220a, 220b, 220c, 220d Terminal 240 Opening portion 250 Mirror portion 252 Mirror 254 Light transmissive resin 300 Resin core 305 Solder layer

Claims (5)

A fusion substrate including an optical waveguide portion and a plurality of wiring portions;
A plurality of light emitting units or a plurality of light receiving units and a plurality of connection terminals; a first line defined by connecting centers of two connection terminals among the plurality of connection terminals; and the first line It is parallel and is sandwiched between second lines defined by connecting the centers of the other two connection terminals different from the two connection terminals, and the distance from the first line and the second line is An optical element substrate having a plurality of optical element arrays arranged symmetrically with respect to an equal axis of symmetry;
Light comprising a conductive solder part that optically couples the optical waveguide part and the plurality of light emitting parts or the plurality of light receiving parts by connecting the plurality of wiring parts and the plurality of connection terminals. module. The optical element substrate has a first optical element array and a second optical element array symmetrically with respect to the symmetry axis;
The light emitting part or the light receiving part at a position closest to the symmetry axis of the first optical element array, and the light emitting part or the light receiving part at a position closest to the symmetry axis of the second optical element array. The distance between the plurality of light emitting sections of the first optical element array or an integer multiple of the pitch between the plurality of light receiving sections, or between the plurality of light receiving sections of the second optical element array or the plurality of the plurality of light receiving sections. The optical module according to claim 1, wherein the distance is defined by an integral multiple of a pitch between the light emitting parts.   The optical module according to claim 2, wherein the plurality of optical element arrays include a surface emitting laser array and a photodiode array.   The optical module according to any one of claims 1 to 3, wherein the solder portion includes a resin core portion having a resin and a conductive layer formed to cover the resin core portion. A fusion substrate including an optical waveguide portion and a plurality of wiring portions;
An optical element substrate having a plurality of connection terminals and having a plurality of optical element arrays including a plurality of light emitting sections or a plurality of light receiving sections;
The optical waveguide portion is formed by having a resin core portion having a resin and a conductive layer formed to cover the resin core portion, and connecting the plurality of wiring portions and the plurality of connection terminals. And a solder part that optically couples the plurality of light emitting units or the plurality of light receiving units.

Images