JP2004288713A - Method of manufacturing optical element mounting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which an optical element mounting device that is less in light transmission loss and high in performance can be manufactured certainly. <P>SOLUTION: The optical element mounting device 31 is provided with an optical element 51, a micro-lens array 41, a positioning reference 55, etc. The optical element 51 has a main surface 53 on which a light emitting section 54 is disposed. The micro-lens array 41 has a plurality of micro-lenses 43 disposed correspondingly to a plurality of optical paths. At the time of manufacturing the mounting device 31, the positioning reference 55 is first formed on the main surface 53 of the optical element 51. Then the micro-lens array 41 is provided on the main surface 53 side of the optical element 51 while the array 41 is positioned by using the positioning reference 55 as a reference. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of manufacturing an optical element mounting device including an optical element and a microlens array, and more particularly to a manufacturing method characterized by a method of aligning an optical element and a microlens array.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the development of information communication technology represented by the Internet and the dramatic improvement in the processing speed of information processing apparatuses, the need for transmitting and receiving large amounts of data such as images has been increasing. In order to freely exchange such large-volume data through information communication equipment, an information transmission speed of 10 Gbps or more is desirable, and optical communication technology is expected to be a technology that can realize such a high-speed communication environment. On the other hand, signals can be transmitted at high speed even on signal transmission paths over relatively short distances, such as connections between wiring boards in equipment, connections between semiconductor chips in wiring boards, and connections in semiconductor chips. Recently, it has been desired. For this reason, it is considered ideal to shift from a conventionally general metal cable or metal wiring to an optical transmission using an optical waveguide or the like.
[0003]
Conventionally, for example, a transmitting side optical package having a light emitting element (eg, VCSEL) mounted thereon and a receiving side optical package having a light receiving element (eg, PD) mounted thereon, and these packages are optically connected by an optical waveguide. Accordingly, there has been proposed an optical printed wiring board in which high-speed signal lines are lightened (for example, see Patent Document 1). A specific example is shown in FIG.
[0004]
A cavity 113 is formed in the first main surface 112 of the substrate 111, and a VCSEL 114 is mounted on the bottom surface of the cavity 113. The VCSEL 114 has a light emitting surface 115 on which a plurality of light emitting units 116 are arranged in an array. On the other hand, a driver IC 118 for operating the VCSEL 114 is mounted on the second main surface 117 of the substrate 111. The VCSEL 114 and the driver IC 118 are electrically connected via a conductor circuit (not shown) of the substrate 111. The cavity 113 is filled with a sealing resin layer 119 made of a transparent resin, and a plurality of microlenses 120 are formed on the surface of the sealing resin layer 119. Since these microlenses 120 are located at positions corresponding to the respective light emitting units 116, when the light emitting units 116 emit light, those lights are condensed when passing through the microlenses 120 and are converted into collimated light (parallel light). Is converted. The collimated light propagates through the gap between the optical printed wiring board 121 and the optical package 122 by air, and then reaches one end (optical path conversion unit) of the optical waveguide 123 on the optical printed wiring board 121. Then, the light propagates through the optical waveguide 123 and reaches the other end (optical path conversion unit), and then enters the light receiving unit of the PD along the reverse path.
[0005]
A procedure for manufacturing such an optical package 122 will be described. First, the VCSEL 114 is mounted on the bottom surface of the cavity 113 on the first main surface 112 side of the substrate 111. Next, after filling and sealing the cavity 113 with a transparent resin, the driver IC 118 is mounted on the second main surface 117 side. Next, a minute amount of a liquid photosensitive resin is dropped on the surface of the sealing resin layer 119 using a dispenser. Since the dropped photosensitive resin becomes hemispherical due to the effect of surface tension, the microlens 120 can be formed by photo-curing the photosensitive resin.
[0006]
[Patent Document 1]
Journal of Japan Institute of Electronics Packaging Vol. 5 No. 5 (2002), "Optical I / O Package Technology Using Microlenses" (pp. 478-481)
[0007]
[Problems to be solved by the invention]
However, in the conventional method of manufacturing the optical package 122, since the dispensing method is employed, it is basically difficult to form the microlenses 120 at positions corresponding to the light emitting units 116 (or light receiving units). For this reason, there is a problem that the microlens 120 is easily deviated from the optical path (that is, the optical axis is easily shifted), and the transmission loss of light is increased.
[0008]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a manufacturing method capable of reliably obtaining a high-performance optical element mounting device with small light transmission loss.
[0009]
Means for Solving the Problems, Functions and Effects
As means for solving the above-mentioned problems, an optical element having a main surface on which at least one of a light receiving unit and a light emitting unit is arranged, and a plurality of microlenses arranged corresponding to a plurality of optical paths are provided. A method of manufacturing an optical element mounting device including a microlens array, wherein a step of forming an alignment reference portion on the main surface of the optical element, and performing the alignment with reference to the alignment reference portion, Providing the microlens array on the main surface side of an element.
[0010]
Therefore, according to this manufacturing method, the microlens array is provided while performing alignment with reference to the alignment reference portion on the main surface of the optical element. It becomes easy to arrange the microlens at the set position. Accordingly, the optical axis of the microlens is aligned with high accuracy, and the transmission loss of light is reduced, so that a high-performance optical element mounting device can be reliably obtained.
[0011]
As the optical elements constituting the optical element mounting device, there are an optical element having a light emitting section arranged on a main surface (ie, a light emitting element) and an optical element having a light receiving section arranged on a main surface (ie, a light receiving element). As the light emitting element, for example, a light emitting diode (Light Emitting Diode; LED), a semiconductor laser diode (Laser Diode; LD), a surface emitting laser (Vertical Cavity Surface Emitting Laser; VCSEL), or the like can be given. These light-emitting elements have a function of converting an input electric signal into an optical signal and emitting the optical signal from a light-emitting portion toward a predetermined portion of the optical waveguide. On the other hand, examples of the light receiving element include a pin photodiode (pin PD) and an avalanche photodiode (APD). These light receiving elements have a function of causing an optical signal emitted from a predetermined portion of the optical waveguide to enter the light receiving section, converting the incident optical signal into an electrical signal, and outputting the electrical signal. Therefore, the light-emitting part of the light-emitting element and the light-receiving part of the light-receiving element are optically connected to the optical waveguide (that is, connected with the optical waveguide aligned with each other's optical axis). The optical element may have both a light emitting unit and a light receiving unit. Suitable materials used for the optical element include, for example, Si, Ge, InGaAs, GaAsP, and GaAlAs.
[0012]
In the optical element, the number of light emitting portions existing on the main surface or the number of light receiving portions existing on the main surface may be one or two or more. In the case of adopting the configuration of the present invention, it is preferable that the number is two or more, and it is particularly preferable that n × m lattices are arranged.
[0013]
The microlens array constituting the optical element mounting device has a plurality of microlenses arranged corresponding to a plurality of optical paths, and is provided on a main surface side of the optical element. The microlens array is formed using an inorganic or organic light transmitting material. The plurality of microlenses have a diameter of 100 μm or less, and are formed on or inside a microlens array. The plurality of microlenses are arranged in the same number and at the same position as the light emitting unit and the light receiving unit. For example, when a VCSEL having n × m light emitting units arranged in a lattice is used as an optical element, a microlens array in which the same number of micro lenses as the light emitting units are arranged in a n × m lattice is used.
[0014]
The optical element mounting device may further include an electronic component for operating the optical element, in addition to the optical element. Specific examples of such electronic components include a semiconductor integrated circuit having a function of an operation circuit of a light emitting element (a so-called driver IC) and a semiconductor integrated circuit connected to a light receiving element (a so-called receiver IC). In addition, the electronic component may be various chip components (for example, a chip transistor, a chip diode, a chip resistor, a chip capacitor, a chip coil, and the like).
[0015]
The optical element mounting device may further include an optical element support on which the optical element is supported and fixed. The formation and material of such an optical element support are not particularly limited, but are preferably, for example, plate-like, and are preferably formed mainly using an insulating material such as resin or ceramic.
[0016]
It is preferable that the optical element support has an accommodation recess capable of accommodating one or two or more optical elements, and the optical element is supported and fixed to a bottom surface of the accommodation recess. With this configuration, the optical element can be entirely covered (that is, packaged) by providing the microlens array so as to cover the opening of the accommodation recess. Therefore, the optical element can be protected without separately providing a sealing member or the like. In addition, with this configuration, since it is relatively easy to airtightly block the optical element, it becomes easy to realize an optical element mounting device that is resistant to moisture and the like and has excellent reliability.
[0017]
Here, the optical element support is preferably a wiring structure having a conductor circuit to which the optical element is electrically connected. When there is an electronic component other than the optical element, it is preferable that the electronic component is also electrically connected to the conductor circuit. Note that the optical element and the electronic component may be provided on the same surface of the wiring structure, or may be provided on different surfaces. As a preferred example of the wiring structure, a multilayer wiring board having a plurality of conductive circuits can be given.
[0018]
Further, in the method of manufacturing the optical element mounting device having the above configuration, for example, a step of forming an alignment reference portion on the main surface of the optical element and a substrate-like microlens array on which a plurality of microlenses are formed are prepared. And a step of mounting and fixing the substrate-shaped microlens array on the main surface side of the optical element while performing positioning with reference to the positioning reference portion.
[0019]
In this manufacturing method, the microlens array installed and fixed on the main surface side of the optical element has a substrate shape, and a plurality of microlenses are formed in advance on the substrate-like microlens array. Therefore, unlike the conventional dispensing method, it is possible to align a plurality of microlenses collectively with respect to a plurality of light emitting units or light receiving units with high accuracy. Therefore, it is possible to easily and efficiently obtain a high-performance optical element mounting device with small light transmission loss.
[0020]
Further, in the method of manufacturing an optical element mounting device having the above configuration, for example, a step of forming a first alignment reference portion on a main surface of the optical element, and a substrate-like microlens array on which a plurality of microlenses are formed And forming a second alignment reference portion on the substrate-shaped microlens array, and aligning the second alignment reference portion with the first alignment reference portion as a reference to perform alignment. And mounting and fixing the substrate-like microlens array on the main surface side of the optical element.
[0021]
Also in the case of this manufacturing method, similarly, the microlens array installed and fixed on the main surface side of the optical element has a substrate shape, and a plurality of microlenses are formed in advance on the substrate-like microlens array. . Therefore, unlike the conventional dispensing method, it is possible to align a plurality of microlenses collectively with respect to a plurality of light emitting units or light receiving units with high accuracy. Therefore, it is possible to easily and efficiently obtain a high-performance optical element mounting device with little light transmission loss.
[0022]
In addition, since the alignment reference part is provided not only on the optical element side but also on the microlens array side and alignment is performed by matching them, compared to the alignment method using only the alignment reference part on the optical element side As a result, the ease and certainty of the alignment are improved.
[0023]
The first alignment reference portion and the second alignment reference portion only need to be capable of aligning the optical element and the microlens array by aligning each other. Not limited. For example, the first alignment reference portion and the second alignment reference portion may be planar ones that do not have a fitting relationship with each other, or may be three-dimensional ones that have a fitting relationship with each other. Good. In the case of a planar one, the state where "the second alignment reference portion is aligned with the first alignment reference portion" is referred to, for example, when the optical element is viewed from the main surface side via a microlens array. Sometimes, it refers to a state in which the second alignment reference portion appears to overlap the first alignment reference portion, which is the reference. In the case of a three-dimensional object, the state in which “the second alignment reference portion is aligned with the first alignment reference portion as a reference” means that the second alignment reference portion is fitted to the first alignment reference portion as a reference. Refers to the state in which
[0024]
Examples of the planar first alignment reference portion and the second alignment reference portion that do not have a fitting relationship with each other include an alignment mark made of a thin film of metal, ink, or the like. In this case, the mark may be different from the color of the surrounding member so that the mark can be distinguished from the surrounding member. Specifically, the first alignment reference portion is a first alignment mark formed of a metal thin film on a main surface of the optical element, and the second alignment reference portion is formed of the substrate-shaped micro-element. It is preferably a second alignment mark formed on the lens array. Note that the second alignment mark may be formed on the surface of the microlens array or may be formed inside. It is preferable that one or more first alignment reference portions are provided on the main surface of the optical element, avoiding a position where the light emitting portion or the light receiving portion is located. Further, the metal thin film serving as the alignment mark is formed by a known method such as sputtering, CVD, plating, and printing.
[0025]
In addition, as an example of the three-dimensional first alignment reference portion and the second alignment reference portion that are in a fitting relationship with each other, the first alignment reference portion has a concave shape and the second alignment reference portion has a convex shape. There are a configuration and a configuration in which the second alignment reference portion is concave and the first alignment reference portion is convex. In addition, if there is such a fitting relationship between the concavities and convexities, the optical element and the microlens array substrate are securely fixed to each other in a state where the displacement is not possible in the plane direction. The convex alignment portion can be formed by a well-known method (for example, paste printing, plating, etching, grinding, molding, and the like). The concave alignment portion can also be formed by a well-known method (for example, drilling, punching, dicing, laser processing, etching, molding, and the like).
[0026]
Here, in the case of using an optical element support such as a wiring structure, a step of supporting and fixing the optical element on its surface (or the bottom surface when there is a housing recess) should be performed. Is good. Specifically, for example, the optical element is fixed by soldering the optical element on a conductor circuit included in the wiring structure. The same applies to electronic components that operate optical elements. Note that the formation of the first alignment reference portion may be performed before or after the step of supporting and fixing the optical element.
[0027]
The plurality of microlenses in the microlens array may be formed before the formation of the second alignment reference portion, may be formed after the formation of the second alignment reference portion, or may be formed after the formation of the second alignment reference portion. May be formed at the same time as the formation. The method for forming the microlens is not particularly limited, and a known method can be employed, but a method using a molding die is preferably employed. According to a method using a molding die, a microlens having a desired shape can be formed with higher precision than a method of dispensing a minute amount of resin with a dispenser (dispensing method). Therefore, a microlens with high light-collecting performance can be easily obtained.
[0028]
Subsequently, a step of fixing the optical element and the microlens array to each other while performing alignment by aligning the second alignment reference portion with the first alignment reference portion as a reference is performed. At this time, the optical element and the microlens array may be directly fixed to each other, or may be indirectly fixed via another member (for example, an optical element support such as a wiring structure). . The fixing method is not particularly limited, and examples thereof include a method using an adhesive or a brazing material.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
[0030]
Hereinafter, a wiring board with an optical element mounting device according to a first embodiment of the present invention will be described in detail with reference to FIGS.
[0031]
As shown in FIG. 1, a main wiring board 11 (wiring board) constituting a wiring board 10 with an optical element mounting device of the present embodiment has a substantially rectangular shape having a first main surface 12 and a second main surface 13. It is a plate member. The main wiring board 11 is a so-called ceramic multilayer wiring board, and has a second main surface 13 and a conductor circuit 16 formed of a metal wiring layer in an inner layer. The main wiring board 11 also includes a via-hole conductor (not shown), and the conductor circuits 16 having different layers are connected to each other via the via-hole conductor. A plurality of pads 14 are provided on the second main surface 13 of the main wiring board 11. Active components such as the transmission-side optical package 31, the reception-side optical package 32, and the IC package 15, and various passive components (not shown) are surface-mounted on the pads 14. A current (electric signal) flows to these components via the conductor circuit 16 of the main wiring board 11 and the like.
[0032]
As shown in FIGS. 1 to 3, a substantially rectangular polymer optical waveguide film 21 is bonded to the second main surface 13 of the main wiring board 11 via an adhesive layer (not shown). The film 21 has a core 23 and a clad 24 surrounding the core 23 from above and below. The core 23 is substantially an optical path through which an optical signal propagates. In the case of the present embodiment, the core 23 and the clad 24 are formed of a transparent polymer material having a different refractive index or the like, specifically, PMMA (polymethyl methacrylate) having a different refractive index or the like. The material forming the core 23 is set so that the refractive index is several percent higher than the material forming the cladding 24. The thickness of each of the core 23 and the clad 24 is set to about several tens of μm. The left end of the film 21 is located in the gap between the receiving optical package 32 and the main wiring board 11, while the right end of the film 21 is located in the gap between the transmitting optical package 31 and the main wiring board 11. At both ends of the film 21, 45 ° inclined surfaces are provided, and on these inclined surfaces, an optical path changing part 22 made of a glossy metal thin film is formed.
[0033]
As shown in FIGS. 1 and 2, the multilayer wiring board 33 (optical element support) constituting the transmission-side optical package 31 (optical element mounting device) has conductor circuits 34 in a plurality of layers. These conductor circuits 34 are interlayer-connected via via-hole conductors 35. On the main surface 36 side of the multilayer wiring board 33, there is provided a cavity 37 which is a housing recess, and a terminal forming pad 38 is formed around the cavity 37. On these terminal forming pads 38, solder balls 39 as external connection terminals are provided. A part connection pad 40 is formed on a part of the conductor circuit 34 arranged on the bottom surface of the cavity 37. On these component connection pads 40, a VCSEL 51 (optical element) and a driver IC 52 as a drive circuit thereof are soldered.
[0034]
Note that, as shown in FIGS. 1 and 3, the receiving optical package 32 (optical device mounting device) also has basically the same structure as the transmitting optical package 31 (optical device mounting device). . However, a photodiode 61 and a receiver IC 62 are accommodated in the cavity 37 instead of the VCSEL 51 (optical element) and the driver IC 52.
[0035]
As shown in FIG. 7 and the like, the VCSEL 51 has a substantially rectangular shape, and one surface is a light emitting surface 53 (main surface). At approximately the center of the light emitting surface 53 (main surface), 3 × 4 light emitting portions 54 are arranged in a lattice. Therefore, these light emitting portions 54 emit laser light of a predetermined wavelength in a direction orthogonal to the second main surface 13 of the main wiring board 11 (that is, in the upward direction in FIGS. 1 and 2). I have. At the four corners of the light emitting surface 53 (main surface), dents 55 are formed as three-dimensional first alignment reference portions. That is, the VCSEL 51 has four depressions 55. These depressions 55 are etching holes having a substantially quadrangular pyramid shape.
[0036]
As shown in FIG. 2 and the like, a microlens array substrate 41 is arranged on the main surface 36 side of the multilayer wiring substrate 33 so as to close the opening of the cavity 37. The outer peripheral portion of the microlens array substrate 41 is joined around the opening of the cavity 37 using an adhesive. As a result, the VCSEL 51 and the driver IC 52 are hermetically sealed. On the outer surface 42 (side surface of the main wiring substrate) of the microlens array substrate 41, 3 × 4 hemispherical microlenses 43 are arranged in a lattice. The plurality of microlenses 43 are located at positions corresponding to the plurality of light emitting units 54. On the other hand, hemispherical projections 45, which are second alignment reference portions, are formed at four positions on the inner surface 44 (side surface of the optical element) of the microlens array substrate 41. These projections 45 are in a fitting relationship with the depressions 55 of the VCSEL 51. Therefore, the VCSEL 51 and the microlens array substrate 41 are fixed in a state where the optical axes of the light emitting portions 54 and the microlenses 43 are aligned with each other so as not to be displaced. Note that the inner surface 44 (side surface of the optical element) of the microlens array substrate 41 and the light emitting surface 53 (main surface) of the VCSEL 51 are not directly joined, and a gap of about 20 μm is left between them.
[0037]
The photodiode 61 shown in FIG. 3 and the like has a substantially rectangular shape, and one surface is a light receiving surface 63 (main surface). At approximately the center of the light receiving surface 63 (main surface), 3 × 4 light receiving portions 64 are arranged in a lattice. Therefore, these light receiving portions 64 are easily adapted to receive laser light emitted in a direction orthogonal to the second main surface 13 of the main wiring board 11 (that is, a downward direction in FIGS. 1 and 3). . At the four corners of the light receiving surface 63 (principal surface), generally quadrangular pyramid-shaped depressions 55 as first alignment reference portions are formed. Each of the projections 45 of the microlens array substrate 41 is fitted into these recesses 55. As a result, the photodiode 61 and the microlens array substrate 41 are fixed so as not to be displaced in a state where the optical axes of the respective light receiving portions 64 and the respective microlenses 43 are aligned.
[0038]
The general operation of the wiring board 10 with the optical element mounting device configured as described above will be briefly described.
[0039]
The VCSEL 51, the driver IC 52, the photodiode 61, and the receiver IC 62 become operable by power supply via the conductor circuit 16, the solder ball 39, the via hole conductor 35, the conductor circuit 34, and the like of the main wiring board 11. The driver IC 52 processes the electric signal sent from the main wiring board 11 and outputs the processed signal to the VCSEL 51. After converting the input electric signal into an optical signal (laser light), the VCSEL 51 emits the laser light from the light emitting unit 54 toward the optical path changing unit 22 of the polymer optical waveguide film 21. Here, each micro lens 43 included in the micro lens array substrate 41 is located at a position corresponding to each light emitting unit 54. Therefore, the emitted laser light is condensed when passing through the micro lens 43 on the outer surface 42 side, and is converted into collimated light. Then, the laser light propagates through the air gap between the transmission-side optical package 31 and the main wiring board 11, and then reaches the optical path conversion section 22 at one end of the polymer optical waveguide film 21 on the main wiring board 11, where the laser light is transmitted. Change the direction of travel by 90 °. Then, after the laser light propagates inside the core 23 along the longitudinal direction, the traveling direction is changed again by 90 ° in the optical path changing portion 22 at the other end of the polymer optical waveguide film 21. The laser light propagates through the gap between the optical package 32 on the receiving side and the main wiring substrate 11, reaches the microlenses 43 on the outer surface 42 of the microlens array substrate 41, and is condensed when passing therethrough. You. When the laser light enters the light receiving portion 64 of the photodiode 61, the photodiode 61 converts the received optical signal into an electric signal and outputs the electric signal to the receiver IC 62. The receiver IC 62 returns the signal to the original state of the electric signal and outputs the signal to the main wiring board 11 side.
[0040]
Next, a method for manufacturing the transmission-side optical package 31 (optical element mounting device) having the above configuration will be described with reference to FIGS. The method of manufacturing the optical package 32 on the receiving side is basically the same as the method of manufacturing the optical package 31 on the transmitting side.
[0041]
First, the microlens array substrate 41 is manufactured in the following procedure. That is, a pair of molding dies 71 and 72 as shown in FIG. 4 are prepared. A plurality of substantially hemispherical concave portions are provided on the molding surface of the molding die 71 and the molding surface of the molding die 72, respectively. Then, a resin plate 46 (for example, an acrylic plate) made of a light transmitting material is prepared, and the resin plate 46 is disposed between the pair of molding dies 71 and 72. By applying a pressing pressure in the thickness direction of the resin plate 46 while heating in this state, a plurality of microlenses 43 are formed on one surface, and a plurality of protrusions 45 are formed on the other surface. That is, in the process of forming the projections 45 on the microlens array substrate 41, a plurality of microlenses 43 are simultaneously formed by performing embossing using the common molding dies 71 and 72 (see FIG. 5). According to the method using the molds 71 and 72, the microlenses 43 having a desired shape can be formed with high accuracy. In addition, since the positional accuracy of the projection 45 with respect to the microlens 43 is extremely high, it is possible to improve the optical axis alignment accuracy of the microlens 43 and to improve the productivity by reducing the number of steps.
[0042]
Also, a multilayer wiring board 33 as an optical element support is manufactured in accordance with a known method (see FIG. 8). For example, a green sheet mainly composed of a ceramic material is formed, a predetermined portion of the green sheet is subjected to hole processing, and then a metal paste for forming a via-hole conductor is filled therein. Further, by printing a metal paste on the surface of the green sheet, a printed layer that will later become the conductor circuit 34 and the pads 38 and 40 is formed. Then, the plurality of green sheets are laminated and pressed to be integrated to form a green sheet laminate. The green sheet laminate is dried, degreased, and fired according to a well-known method to form a multilayer wiring board 33. The cavity 37 is preferably formed at a stage before firing. Then, after the VCSEL 51 and the driver IC 52 are mounted on the component connection pads 40 on the bottom surface of the cavity 37, reflow is performed and they are soldered (see FIG. 9). It is to be noted that a recess 55 is formed in the light emitting surface 53 in advance by performing wet etching before mounting the VCSEL 51. Since the VCSEL 51 of the present embodiment is made of a semiconductor material such as Si or the like, the recess 55 having a suitable shape can be formed relatively easily by etching.
[0043]
Subsequently, after applying an adhesive in advance around the opening of the cavity 37, the microlens array substrate 41 is disposed above the main surface 36 of the multilayer wiring substrate 33. At this time, the surface of the microlens array substrate 41 on which the protrusions 45 are provided is directed toward the multilayer wiring substrate 33 (see FIG. 10). Then, the microlens array substrate 41 is moved closer to the multilayer wiring substrate 33, and each projection 45 and each recess 55 are fitted (see FIG. 11). As a result, the VCSEL 51 and the microlens array substrate 41 are fixed so as not to be displaced from each other while ensuring that the optical axes of the light emitting portions 54 and the microlenses 43 are aligned. At this time, the microlens array substrate 41 is adhered to the main surface 36 and the opening of the cavity 37 is completely closed, so that the VCSEL 51 and the driver IC 52 are hermetically sealed.
[0044]
Thereafter, if a solder ball 39 is provided on the terminal forming pad 38, a desired transmission-side optical package 31 is completed. Furthermore, if the transmission-side optical package 31 and the reception-side optical package 32 manufactured as described above are surface-mounted on the second main surface 13 of the main wiring board 11 including the polymer optical waveguide film 21, a desired optical element can be obtained. The wiring board 10 with a mounting device can be obtained.
[0045]
Therefore, according to the manufacturing method of the present embodiment, the following effects can be obtained.
[0046]
(1) In the present embodiment, the VCSEL 51 and the microlens array substrate 41 are aligned with each other while performing alignment by fitting the recess 55 as the first alignment reference portion and the projection 45 as the second alignment reference portion. The transmitting side optical package 31 is manufactured through a process of fixing the optical package 31 to each other. Similarly, the receiving side optical package 32 is manufactured through a process of fixing the photodiode 61 and the microlens array substrate 41 to each other while performing positioning by fitting the recess 55 and the projection 45 together. Therefore, according to this manufacturing method, it becomes easier to dispose the microlens 43 at a position corresponding to the light emitting unit 54 or the light receiving unit 64 as compared with the conventional method of forming the microlens 43 by the dispensing method. Moreover, in the case of this manufacturing method, unlike the conventional dispensing method, it is possible to align the plurality of microlenses 43 collectively with the plurality of light emitting units 54 or the light receiving units 64 with high accuracy. In addition, since the alignment reference portions are provided not only on the optical element side but also on the microlens array substrate 41 side and alignment is performed by fitting them, the ease and reliability of the alignment are improved.
[0047]
As described above, according to the manufacturing method of the present embodiment, it is possible to obtain a high-performance transmission-side optical package 31 and a high-performance reception-side optical package 32 with little light transmission loss, in a very simple and efficient manner.
[0048]
(2) In the manufacturing method according to the present embodiment, the positioning is performed by the three-dimensional positioning reference portions (that is, the depression 55 and the projection 45) that are in a fitting relationship with each other. Therefore, there is an advantage that a positional shift in the surface direction hardly occurs after the alignment between the optical element and the microlens array substrate 41. Another advantage is that high-accuracy alignment can be performed without performing image recognition using a CCD camera or the like.
[Second embodiment]
[0049]
Next, a manufacturing method according to the second embodiment will be described with reference to FIGS. Here, the differences from the first embodiment will be described, but the same points as those in the first embodiment will only be assigned the same member numbers.
[0050]
In the first embodiment, the recess 55 and the projection 45, which are three-dimensional positioning reference portions, are formed, and these are fitted to each other to perform positioning between the optical element and the microlens array substrate 41. . On the other hand, in the present embodiment, a planar alignment reference portion is formed, and the optical element and the microlens array substrate 41 are aligned using them.
[0051]
As shown in FIGS. 13 and 14, on the main surface 53 of the VCSEL 51 (optical element), a first alignment mark 86 made of a metal thin film is formed in advance. Specifically, a predetermined mask is formed on the main surface 53 of the VCSEL 51 (optical element), and gold is sputtered in this state to form circular first alignment marks 86 at a plurality of positions. On the other hand, as shown in FIGS. 12 and 14, a second alignment mark 87 made of a metal thin film is formed in advance on the microlens array substrate 41 having a plurality of microlenses 43. Specifically, a predetermined mask is formed on the surface of the microlens array substrate 41, and gold is sputtered in this state, thereby forming a hollow second alignment mark 87 at a plurality of locations. . Note that each second alignment mark 87 is arranged corresponding to the position of each first alignment mark 86. The hollow portion of the second alignment mark 87 is larger than the first alignment mark 86. Therefore, when the VCSEL 51 and the microlens array substrate 41 are aligned, it looks as if the first alignment mark 86 is located exactly in the hollow portion of the second alignment mark 87.
[0052]
Then, after the VCSEL 51 and the driver IC 52 are soldered to the bottom surface of the cavity 37 of the multilayer wiring board 33, the VCSEL 51 and the microlens array substrate 41 are fixed as follows. That is, as shown in FIG. 14, after applying an adhesive in advance around the opening of the cavity 37, the microlens array substrate 41 is arranged above the main surface 36 side of the multilayer wiring board 33.
[0053]
Above the microlens array substrate 41, imaging means such as a CCD camera (not shown) is arranged. Since the microlens array substrate 41 is made of a light transmitting material, the CCD camera can catch not only the second alignment mark 87 but also the first alignment mark 86 via the microlens array substrate 41. Data captured by the CCD camera is taken into a computer (not shown). The computer performs a predetermined image recognition process and, based on the processing result, grasps the relative position of the second alignment mark 87 with reference to the first alignment mark 86. The computer is connected to an XY table (not shown) via an XY table driving means (not shown), and outputs a predetermined driving signal to the XY table driving means. Therefore, when the second alignment mark 87 is misaligned with respect to the first alignment mark 86, the computer outputs a signal for driving the XY table in a direction to correct the misalignment. When such a correction operation is completed, the first alignment mark 86 is located at the center of the hollow portion of the second alignment mark 87. In other words, the second alignment mark 87 is aligned with the first alignment mark 86 as a reference. Next, the microlens array substrate 41 is brought close to the multilayer wiring substrate 33, and the microlens array substrate 41 and the multilayer wiring substrate 33 are bonded (see FIG. 15). As described above, the VCSEL 51 and the microlens array substrate 41 are fixed while securely aligning the optical axes of the light emitting units 54 and the microlenses 43.
[0054]
Therefore, even with the manufacturing method according to the present embodiment, it is possible to easily and efficiently obtain the high-performance transmission-side optical package 31 and high-performance reception-side optical package 32 with little light transmission loss.
[0055]
Note that the embodiment of the present invention may be modified as follows.
[0056]
For example, while a projection (first alignment reference portion) is provided on the main surface of the optical element, a through-hole (second alignment reference portion) which is fitted with the projection is provided on the microlens array substrate 41, Alignment may be achieved with these fitting relationships.
[0057]
In the second embodiment, the metal thin film formed by sputtering is used as the first alignment mark 86. However, the present invention is not limited to this. For example, an existing structure on the main surface of the optical element may be used as the first alignment mark 86. It may be used as the alignment mark 86. As a specific example, for example, when there is a connection pad on the outer peripheral portion of the main surface of the optical element, the pad may be used as the first alignment mark 86.
[0058]
The multilayer wiring board 33 serving as the optical element support is not limited to the ceramic multilayer wiring board as in the above embodiment, but may be a resin multilayer wiring board or the like. Further, not only a multilayer board having three or more layers of conductor circuits 34 but also a double-sided board or a single-sided board can be used as the optical element support. Further, since the optical element support is not an essential component, it can be omitted. In this case, for example, the optical element may be supported and fixed to the microlens array substrate 41.
[0059]
Next, in addition to the technical ideas described in the claims, technical ideas grasped by the above-described embodiments will be listed below.
[0060]
(1) an optical element support, an optical element supported and fixed on the optical element support, and having a main surface on which at least one of a light receiving section and a light emitting section is arranged; In a method for manufacturing an optical element mounting device including an electronic component supported and fixed and operating the optical element, and a microlens array having a plurality of microlenses arranged corresponding to a plurality of optical paths, Forming a positioning reference portion on the main surface, supporting and fixing the optical element on which the positioning reference portion is formed on the optical element support, and performing positioning with reference to the positioning reference portion. Providing the microlens array on the main surface side of the optical element while performing the method.
[0061]
(2) A wiring structure having a conductor circuit and a housing recess, and supported and fixed on the bottom surface of the housing recess, and electrically connected to the conductor circuit, among the plurality of light receiving units and the plurality of light emitting units. An optical element having a main surface at least one of which is disposed; an electronic component that is supported and fixed on the bottom surface of the housing recess, is electrically connected to the conductor circuit, and operates the optical element; A method for manufacturing an optical element mounting device including a microlens array having a plurality of microlenses arranged corresponding to an optical path, wherein a step of forming an alignment reference portion on a main surface of the optical element; A step of supporting and fixing the optical element on which the alignment reference portion is formed on the bottom surface, and performing alignment with reference to the alignment reference portion while the main surface of the optical element. The method of manufacturing an optical element mounting device for a step of providing a microlens array, comprising the in.
[Brief description of the drawings]
FIG. 1 is an overall schematic cross-sectional view showing a wiring board with an optical element mounting device according to a first embodiment of the invention.
FIG. 2 is a cross-sectional view illustrating a transmission-side optical package (optical element mounting device) according to the first embodiment.
FIG. 3 is a cross-sectional view illustrating a receiving-side optical package (optical element mounting device) according to the first embodiment.
FIG. 4 is a schematic sectional view showing a resin plate and a molding die in the manufacturing process of the first embodiment.
FIG. 5 is a schematic cross-sectional view showing a state in which a microlens array substrate is being manufactured using a mold in the manufacturing process.
FIG. 6 is a schematic plan view showing a microlens array substrate on which protrusions (second alignment reference portions) are formed in the same manufacturing process.
FIG. 7 is a schematic plan view showing a VCSEL (optical element) in which a recess (first alignment reference portion) is formed in the manufacturing process.
FIG. 8 is a schematic sectional view showing a multilayer wiring board provided with a cavity in the same manufacturing process.
FIG. 9 is a schematic cross-sectional view showing a state in which a VCSEL (optical element) and a driver IC are mounted on a multilayer wiring board in the same manufacturing process.
FIG. 10 is a schematic cross-sectional view showing a state immediately before bonding while aligning the microlens array substrate and the VCSEL (optical element) in the same manufacturing process.
FIG. 11 is a schematic cross-sectional view showing a state where the microlens array substrate and the VCSEL (optical element) are joined together while being aligned in the same manufacturing process.
FIG. 12 is a schematic plan view showing a microlens array substrate on which a second alignment mark (a second alignment reference portion) is formed in the manufacturing process of the second embodiment.
FIG. 13 is a schematic plan view showing a VCSEL (optical element) on which a first alignment mark (first alignment reference portion) is formed in the manufacturing process.
FIG. 14 is a schematic cross-sectional view showing a state immediately before bonding while aligning the microlens array substrate and the VCSEL (optical element) in the manufacturing process.
FIG. 15 is a cross-sectional view illustrating a transmission-side optical package (optical element mounting device) according to a second embodiment.
FIG. 16 is a cross-sectional view showing a conventional transmission-side optical package (optical element mounting device).
[Explanation of symbols]
Reference numeral 31 denotes a transmitting side optical package as an optical element mounting device 32... A receiving side optical package 41 as an optical element mounting device... A micro lens array substrate 43 as a micro lens array... Micro lenses 45. Projection 51 of the optical element VCSEL
53 a main surface (of the VCSEL which is an optical element) 54 a light emitting portion 55 a dent 61 which is a second alignment reference portion a photodiode 63 which is an optical element and a main surface 64 of a photodiode which is an optical element Light receiving portion 86: first alignment mark 87 as (first) alignment reference portion second alignment mark as second alignment reference portion

Claims (4)

An optical element having a main surface on which at least one of the light receiving unit and the light emitting unit is arranged,
A method of manufacturing an optical element mounting device comprising: a microlens array having a plurality of microlenses arranged corresponding to a plurality of optical paths;
Forming a positioning reference portion on the main surface of the optical element,
Providing the microlens array on the main surface side of the optical element while performing alignment with reference to the alignment reference section. An optical element having a main surface on which at least one of the light receiving unit and the light emitting unit is arranged,
A method of manufacturing an optical element mounting device comprising: a microlens array having a plurality of microlenses arranged corresponding to a plurality of optical paths;
Forming a positioning reference portion on the main surface of the optical element,
A step of preparing a substrate-like microlens array on which a plurality of microlenses are formed,
Mounting and fixing the substrate-shaped microlens array on the main surface side of the optical element while performing alignment with reference to the alignment reference portion. . An optical element having a main surface on which at least one of the light receiving unit and the light emitting unit is arranged,
A method of manufacturing an optical element mounting device comprising: a microlens array having a plurality of microlenses arranged corresponding to a plurality of optical paths;
Forming a first alignment reference portion on the main surface of the optical element;
Preparing a substrate-shaped microlens array on which a plurality of microlenses are formed, and forming a second alignment reference portion on the substrate-shaped microlens array;
Mounting and fixing the substrate-shaped microlens array on the main surface side of the optical element while performing alignment by aligning the second alignment reference portion with the first alignment reference portion as a reference. The manufacturing method of the optical element mounting apparatus characterized by including these. The first alignment reference portion is a first alignment mark formed of a metal thin film on a main surface of the optical element, and the second alignment reference portion is formed on the substrate-shaped microlens array. 4. The method according to claim 3, wherein the second alignment mark is a second alignment mark.

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