JP4671480B2 - Optical mounting substrate manufacturing method and optical module manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, an optical waveguide such as an optical fiber and an optical waveguide, and an optical semiconductor element such as a light emitting element and a light receiving element can be arranged on a substrate, and these optical components can be optically coupled with high accuracy. The present invention also relates to an optical mounting substrate for optical devices and an optical module using the same, which are used in the field of measurement and the like.
[0002]
[Prior art]
In recent years, optical fiber communication has been put into practical use in the fields of CATV and public communication. Light using technology that positions and mounts optical semiconductor elements and fibers with high accuracy only on an optical mounting substrate using a silicon substrate (also called a submount or Si platform mounted in a package). Modules are actively developed.
[0003]
When an optical semiconductor element such as a laser diode or a photodiode is coupled to an optical fiber, the center (core) of the optical semiconductor element and the optical fiber must be aligned in a straight line with an accuracy of ± 1.0 μm in the horizontal and vertical directions. The light generated from the optical semiconductor element cannot be transmitted to the optical fiber without loss.
[0004]
In order to precisely align the optical semiconductor element and the optical fiber, an optical mounting substrate on which a V-groove for mounting the optical fiber and a solder bump (solder bump) for mounting the optical semiconductor element is used.
[0005]
The method of self-aligning an optical fiber and an optical semiconductor element using an optical mounting substrate is to mount an optical fiber on a silicon substrate having a V-groove capable of precise dimension control, and to solder bump the light emitting portion of the optical semiconductor element. To match the center of the optical fiber. In this method, since the optical semiconductor element and the optical fiber are aligned with a small error of about ± 1 μm in the vertical and horizontal directions, good optical coupling efficiency can be obtained.
[0006]
As shown in FIGS. 7 and 8, the conventional optical mounting substrate SS that self-aligns the optical fiber 38 and the optical semiconductor element 37 is vacuum-deposited and deposited on a predetermined portion on the silicon substrate 31 having an insulating film 32 formed on the surface. A metal pad 33 is formed by a photoetching method, and a V-shaped groove 36 having a V-shaped cross section is formed by an anisotropic etching method.
[0007]
In this detailed manufacturing method, as shown in FIG. 8, a first insulating film 32 is formed on the surface of a silicon substrate 31, and a pair of metal pads 33 are formed on the first insulating film 32 at a predetermined interval. A step of forming, a step of forming a second insulating film 34 on the first insulating film 32 and the pair of metal pads 33, and a pair of metal pads 33 on the second insulating film 34, respectively. Along the direction parallel to the surface of the silicon substrate 31 and perpendicular to the direction connecting the second openings in the middle between the pair of second openings and the pair of second openings, Forming a photosensitive film (not shown) having a first opening in which one end is not overlapped with both second openings and the other end is extended to the side end surface of the silicon substrate 31; (Not shown) as a mask, the first insulating film 32 and the second exposed through the first and second openings. The step of removing the edge film 34 to expose the surfaces of the silicon substrate 31 and the metal pad 33, and the removal of the photosensitive film (not shown) and using the first insulating film 32 and the second insulating film 34 as an etching mask. A step of forming a V-groove 36 in the exposed portion of the silicon substrate 31, and a step of forming a solder bump 35 on the metal pad 33.
[0008]
At this time, the second opening has an opening area smaller than the surface area of the corresponding metal pad 33, and the center thereof is formed at a position coincident with the center position on the surface of the corresponding metal pad 33.
[0009]
[Problems to be solved by the invention]
However, as shown in FIGS. 7 and 8, in the conventional manufacturing method, as described above, the insulating film structure on the substrate has a two-layer structure, and in addition, in order to prevent the solder bump 35 from protruding, a metal pad as a conductor is used. It was necessary to form the second insulating film 34 on 33.
[0010]
Therefore, the second insulating film 34 formed on the upper part of the metal pad 33 has a problem in adhesion to the surface of the metal pad 33 or the first insulating film 32, and has a problem that peeling occurs from the film interface. When the insulating film is peeled off, the solder bump 35 protrudes from the metal pad 33, contacts with other metal parts to cause a short circuit, or the mounting position of the optical semiconductor element 37 is shifted. The optical coupling efficiency between the optical fiber 38 and the optical fiber 38 is reduced.
[0011]
  Accordingly, an object of the present invention is to provide a self-aligned optical mounting substrate that does not cause separation of the insulating film, prevents the occurrence of solder bump protrusion, and improves the optical coupling efficiency between the optical semiconductor element and the optical fiber.PlankProduction methodandOptical moduleManufacturing methodIs to provide.
[0012]
[Means for Solving the Problems]
  To solve the above problem,Optical mounting substrate of the present inventionManufacturing methodHas a mounting groove for disposing an optical waveguide and an optical semiconductor element optically connected to the optical waveguide on the substrate.A conductor layer and a solder layer are sequentially laminated in a recess of a single layer insulating film.Mounting conductorWhenFormingThe mask for forming the mounting groove is the same as the mask for forming the recess, and the recess is aligned with the mounting groove.Optical mounting boardManufacturing methodBecauseForming the insulating film on the upper surface of the substrate, and forming a photosensitive film having an opening of a first mounting groove pattern and an opening of a mounting marker and optical semiconductor element mounting conductor pattern on the insulating film; Using the photosensitive film as a mask, the surface of the substrate is not exposed in the region exposed by the opening of the first mounting groove pattern and the opening of the mounting marker and optical semiconductor element mounting conductor pattern. After removing the photosensitive film in the removing step and the previous process, a photosensitive film having an opening for forming the mounting conductor is formed in a processed portion of the mounting marker and optical semiconductor element mounting conductor pattern. A step, an etching step for making at least one side surface of the processed portion of the conductor pattern for mounting marker and optical semiconductor element mounting into a slope, and the mounting marker function A step of forming the conductor layer in the processed portion of the semiconductor element mounting conductor pattern; and after removing the photosensitive film in the previous step, an opening of the second mounting groove pattern in the processed portion of the first mounting groove pattern And a step of removing the insulating film in the region exposed by the opening of the second mounting groove pattern so that the substrate surface is exposed using the photosensitive film as a mask. And a step of forming the mounting groove in a region where the substrate surface is exposed after removing the photosensitive film in the previous step, and an opening for forming a solder bump as the solder layer on the conductor layer Forming a photosensitive film; using the photosensitive film as a mask; forming the solder bump on the conductor layer; and removing all the photosensitive film on the substrate surface; form Having a comprising the steps of:It is characterized by.
[0013]
  Also, the optical module of the present inventionManufacturing methodOf the above optical mounting boardThe optical mounting substrate obtained by the manufacturing methodIn the mounting grooveSaidOptical waveguideA step of arranging, andOptical connection to the optical waveguide on the mounting conductorSaidArranged optical semiconductor elementAnd a step of performing.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings schematically shown.
[0017]
As shown in FIGS. 1 and 2, an optical mounting substrate S according to the present invention is a mounting groove 11 for disposing an optical waveguide on the substrate 1 and an optical semiconductor element optically connected to the optical waveguide. A mounting conductor for disposing a light emitting element 16 such as a semiconductor laser and a light receiving element 15 such as a photodiode for monitoring the emitted light of the light emitting element 16 is formed. The conductor layer 8 and the solder layer 12 are sequentially laminated in the recess 2a of the insulating film 2 made of a single layer that is precisely aligned with the groove 11.
[0018]
Here, as shown in FIG. 2, an inclined surface 2b is formed in the recess 2a, and the conductor layer 8 is insulated via a conductor pattern 21 formed on the inclined surface 2b formed on one side of the recess 2a. The film 2 is connected to a wiring pattern 14a formed on a surface higher than the bottom surface of the recess 2a. The same applies to the wiring pattern 14b shown in FIG. Further, since the surface of the conductor layer 8 is lower than the surface of the insulating film 2 on which the wiring pattern is formed, when the solder is filled in the recess 2a, the solder layer 12 disposed on the conductor layer 8 is placed outside the recess 2a. I try not to let it stick out.
[0019]
Further, the optical module of the present invention has a light emitting element 16 and a light receiving element 17 for optically connecting, for example, an optical fiber 18 that is an optical waveguide in the mounting groove of the optical mounting substrate S to the optical fiber 18 on the mounting conductor. Is provided.
[0020]
The above configuration will be described in more detail. The optical mounting substrate S is an oxide film or nitridation formed by chemical vapor deposition or thermal oxidation on a substrate 1 having a predetermined orientation as a main surface and capable of anisotropic etching such as silicon single crystal. A single-layer insulating film 2 made of a film or the like, a mounting groove 11 formed by etching to dispose an optical fiber 18 as an optical waveguide, and a mounting groove positioned with respect to the mounting groove 11 A lower conductor layer 8 for disposing the optical semiconductor elements 16 and 17 also serving as markers, and an upper conductor disposed on a part of the wires 14a, 14b, 15a and 15b and the lower conductor layer 8 A solder bump (solder layer) 12 is formed to form a mounting conductor. In the figure, reference numeral 14 denotes a wiring connected to the back-side electrode of the optical semiconductor element via the solder layer 12, and reference numeral 15 denotes a wiring connected to the front-side electrode of the optical semiconductor element via a bonding wire or the like.
[0021]
The lower conductor layer 8 for disposing the optical semiconductor elements 16 and 17 that also serve as mounting markers positioned with respect to the mounting groove 11 is located above the substrate surface and is a main part of the insulating film 2. Solder bumps 12 for mounting the optical semiconductor elements 16 and 17 are formed on the lower conductor layer 8 while being formed on the regions 7a and 7b processed so as to be a certain depth deeper than the surface.
[0022]
One main surface of the single-layer insulating film on which the wirings 14a, 14b, 15a and 15b for driving the optical semiconductor elements 16 and 17 are formed is the formation of the lower conductor layer 8 for disposing the optical semiconductor elements 16 and 17 The thickness of the lower conductor layer 8 is at least higher than the region to be formed.
[0023]
As shown in FIG. 2, regions 7a and 7b located above the substrate surface and where the lower conductor layer 8 for arranging the optical semiconductor elements 16 and 17 is formed are located above the substrate surface and are insulated. The film 2 is processed so as to be deeper than at least the thickness of the lower conductor layer 8 from one main surface of the film 2. The regions 7a and 7b processed so as to be deeper than at least the thickness of the lower conductor layer 8 from one main surface of the insulating film 2 are formed to a depth of 0.8 μm or more. The reason why the regions 7a and 7b are processed to be deeper than the thickness of the lower conductor layer 8 is that the depth of the processed regions 7a and 7b is smaller than the thickness of the lower conductor layer 8 (when the depth is 0.8 μm or less). This is because when the optical semiconductor elements 16 and 17 are mounted after the solder bump 12 is formed, the solder bump 12 protrudes from the lower conductor layer 8 and the solder bump 12 comes into contact with other wiring. In general, since the thickness of the lower conductor layer 8 is 0.3 to 0.8 μm and the thickness of the solder bump 12 is 0.2 to 5.0 μm, the depth of the processed regions 7a and 7b is preferably 0.00. The thickness is 6 to 6.0 μm, and more preferably 1.0 to 3.0 μm.
[0024]
Next, a method for manufacturing the optical mounting substrate S will be described.
[0025]
As shown in FIGS. 3A to 3I, first, a single-layer insulating film 2 is formed on the upper surface of the substrate 1 by using a plasma CVD method, a sputtering method, or the like. Next, in order to form the opening 4 of the first mounting groove pattern and the openings 5a and 5b of the optical semiconductor element mounting conductor pattern on the single-layer insulating film 2, the photosensitive film 3 is applied and subjected to a photolithography process. Each opening 4, 5a, 5b is formed.
[0026]
At this time, the mask for forming the opening 4 of the first mounting groove pattern and the mask for forming the openings 5a and 5b of the optical semiconductor element mounting conductor pattern, which also serve as mounting markers for the optical semiconductor element, are the same. By using this photomask, the insulating film 2 in these regions is removed, and the mounting marker and optical semiconductor element mounting conductor aligned with the mounting groove pattern processing portion 6 with high accuracy Patterned portions 7a and 7b can be formed.
[0027]
Next, the photosensitive film 3 is applied to the conductor pattern processing portions 7a and 7b for mounting marker and optical semiconductor element mounting on the single-layer insulating film 2 in order to form the optical semiconductor element mounting conductor. Openings 9a and 9b are formed. At this time, in order to form the wirings 14a and 14b connected to the mounting marker and optical semiconductor element lower conductor layer 8, at least one side surface part of the optical semiconductor element mounting conductor pattern processing portions 7a and 7b is inclined. Wet etching is performed.
[0028]
Then, the surface of the single-layer insulating film 2 of the conductive pattern processing portion 6 for mounting an optical semiconductor element is exposed, and the insulating film surface is exposed to a mounting marker and optical semiconductor element lower conductor using an electron beam evaporation method, a sputtering method, or the like. Layer 8 and wirings 14a, 14b, 15a and 15b are formed. Further, the photosensitive film 3 is applied to form the opening 10 of the second mounting groove pattern in the mounting groove pattern processing portion 6, and the opening 10 is formed by a photolithography process.
[0029]
Then, an opening 10 is formed to expose the substrate surface, and anisotropic etching is performed with an alkaline solution such as potassium hydroxide (KOH), sodium hydroxide (NaOH), tetramethylammonium hydroxide (TMAH), and the like. The wave body mounting groove 11 is formed with high accuracy.
[0030]
Further, the photosensitive film 3 is applied on the substrate 1 on which the mounting marker and optical semiconductor element lower conductor layer 8 formed on the optical semiconductor element mounting conductor pattern processing portion 6 and the optical waveguide mounting groove 11 are formed, Thereafter, solder bump forming openings 12a and 12b are formed on the mounting marker and optical semiconductor element lower conductor layer 8 by a photolithography process. Then, the solder bumps 12 are formed using an electron beam vapor deposition method, a sputtering method, or the like. Finally, after all the photosensitive film 3 on the substrate surface is removed, the optical waveguide stopper rectangular groove 13 is formed.
[0031]
Next, the optical module of the present invention will be described. In the optical module, an optical fiber 18 that is an optical waveguide is mounted in a mounting groove 11 of an optical mounting substrate S obtained by the above-described manufacturing method, and a mounting conductor that is a mounting conductor formed on a single-layer insulating film 2. A light emitting element 16 and a light receiving element 17 are arranged via solder bumps 12 on the marker / optical semiconductor element lower conductor layer 8, and further, these optical semiconductor elements 16 and 17 are formed on the substrate surface by bonding wires. 2 is connected to the wirings 15 a and 15 b on the optical line 2 to enable optical coupling between the optical semiconductor element 16 and the end of the optical fiber 18.
[0032]
Thus, in the optical mounting substrate for optically coupling the optical waveguide and the optical semiconductor element, a single layer insulating film is formed on the substrate surface, and the optical semiconductor element mounting conductor and the formation area of the solder bump are By making the height higher than the substrate surface and lower than the surface of the mounting conductor formed on the single-layer insulating film, the solder bumps melted by the step formed by the single-layer insulating film without causing the insulating film to peel off. Protruding to other areas can be prevented.
[0033]
  Also, mounting grooves for mounting optical waveguides and mounting markers and conductors for mounting optical semiconductor elementsWhenA mask for forming an opening for a mounting groove pattern and a mask for forming a conductor pattern for mounting an optical semiconductor element that also serves as a mounting marker for the optical semiconductor elementWhenAre the same, that is, each pattern is on the same mask, mounted with an optical waveguide formed using thisGrooveAnd mounting marker and conductor for mounting optical semiconductor elementsWhenHas no relative displacement, optical semiconductor element and optical waveguideWhenCan be mounted with high accuracy. As a result, an optical module having an excellent optical coupling efficiency and an optical module comprising the optical waveguide in the mounting groove of the optical mounting substrate and the optical semiconductor element optically connected to the optical waveguide on the mounting conductor, and the configuration thereof An optical mounting substrate can be provided.
[0034]
【Example】
Examples in which the optical mounting substrate according to the present invention is more concretely described below.
<Example 1>
First, as shown in FIG. 3A, a silicon oxide film 2 serving as an insulating film is formed on a substrate made of silicon single crystal by a sputtering method to a thickness of 3.5 μm, and then a silicon oxide film 2 is formed. The photosensitive film 3 is applied thereon, and is performed by photolithography using a mask on which the first mounting groove pattern and the optical semiconductor element mounting conductor pattern that also serves as the mounting marker for the optical semiconductor element are drawn. Openings 4, 5a and 5b were formed.
[0035]
Then, as shown in FIG. 3B, the silicon oxide film 2 exposed through the openings 4, 5a, and 5b is removed by wet etching using buffered hydrofluoric acid, and each of them has a depth of 3.0 μm. 1 Mounting groove pattern processing portion 6 and mounting marker and optical semiconductor element mounting conductor pattern processing portions 7a and 7b aligned with high precision were formed.
[0036]
Next, as shown in FIG. 3 (c), a photosensitive film 3 is applied on the silicon oxide film 2 having a plurality of processed portions, and an optical semiconductor element mounting conductor pattern that also serves as an optical semiconductor element mounting marker, Then, photolithography is performed using a mask on which a driving conductor pattern is drawn, and openings 9a and 9b are formed to expose the surface of the insulating film 2 of the conductor pattern processing portion 6 for mounting an optical semiconductor element. Using the electron beam evaporation method on the surface, the mounting marker and optical semiconductor element lower conductor layer 8 and the wirings 14a, 14b, 15a and 15b are Ti / Pt / Au 0.1 μm / 0.2 μm in the order of lower layer / upper layer. The film was formed at /0.5 μm.
[0037]
Further, as shown in FIGS. 3D and 3E, a photosensitive layer is exposed on the silicon oxide film 2 having a plurality of processed portions, a mounting marker and optical semiconductor element lower conductor layer 8, and wirings 14a, 14b, 15a, and 15b. The film 3 is applied, and photolithography is performed using a mask on which the second mounting groove pattern is drawn, the opening 10 is formed, the silicon substrate surface is exposed, and all the photosensitive film 3 on the substrate is removed. After that, as shown in FIG. 3F, the pattern on the silicon substrate is subjected to anisotropic etching using KOH (concentration: 43 wt%, temperature: 63.5 ° C.), and the waveguide is mounted on the silicon substrate. A groove 11 was formed.
[0038]
Next, as shown in FIG. 3G, the photosensitive film 3 is applied on the substrate 1 on which the mounting marker / optical semiconductor element lower conductor layer 8 and the waveguide mounting groove 11 are formed, and the optical semiconductor element mounting is performed. Photolithography is performed using a mask on which a solder bump pattern formed on the conductor for drawing is formed, openings 12a and 12b are formed to expose the surface of the optical semiconductor element mounting conductor, and an electron beam is formed on the conductor surface. Solder bumps 12 (weight ratio Au: Sn = 70: 30, thickness 2 μm) are formed using a vapor deposition method.
[0039]
Finally, as shown in FIGS. 3H and 3I, after all the photosensitive film 3 on the substrate surface is removed, the optical waveguide stopper rectangular groove 13 is formed by machining by dicing or the like, and then cut. It was.
[0040]
As a result, a single-layer insulating film is formed on the substrate surface in the mounting portion of the optical waveguide and the optical semiconductor element, and the formation region of the optical semiconductor element mounting conductor and the solder bump is higher than the substrate surface and is a single-layer insulating film. By making it lower than the surface of the mounting conductor formed on the film, it is possible to prevent peeling of the insulating film and to prevent the melted solder bumps from protruding into other areas due to the step formed by the single-layer insulating film. It was.
[0041]
In addition, for the mounting groove for mounting the optical waveguide and the mounting marker and optical semiconductor element mounting conductor, the respective patterns are on the same mask, and the mounting groove for mounting the optical waveguide formed using this The mounting marker and optical semiconductor element mounting conductor has no relative displacement, and the optical semiconductor element and the optical waveguide can be mounted with high accuracy, thereby providing an optical mounting substrate for constructing an optical module with excellent optical coupling efficiency. did it.
<Example 2>
Hereinafter, another embodiment of the optical semiconductor mounting substrate according to the present invention will be described.
[0042]
First, as shown in FIG. 6A, a silicon nitride film 2 serving as an insulating film was formed with a thickness of 5 μm on a substrate made of silicon single crystal by plasma CVD. Next, a photosensitive film 3 is applied on the silicon nitride film 2, and a photo using a mask on which a first mounting groove pattern and an optical semiconductor element mounting conductor pattern that also serves as an optical semiconductor element mounting marker are drawn. Respective openings 4, 5a and 5b were formed by lithography.
[0043]
Then, as shown in FIG. 6B, the silicon nitride film 2 exposed through the openings 4, 5a and 5b is removed by wet etching using buffer nitriding, and the first having a depth of 3.1 μm. The mounting marker and optical semiconductor element mounting conductor pattern processing portions 7a and 7b aligned with the mounting groove pattern processing portion 6 with high accuracy were formed.
[0044]
Next, as shown in FIG. 6C, a photosensitive film 3 is applied on the silicon nitride film 2 having a plurality of processed portions, and an optical semiconductor element mounting conductor pattern that also serves as an optical semiconductor element mounting marker; Then, photolithography is performed using a mask on which a driving conductor pattern is drawn, and openings 9a and 9b are formed to expose the surface of the insulating film 2 of the conductor pattern processing portion 6 for mounting an optical semiconductor element. Using resistance heating vapor deposition on the surface, the mounting marker and optical semiconductor element lower conductor layer 8 and the wirings 14a, 14b, 15a and 15b are formed in the order of lower layer / upper layer and Cr / Au is formed at 0.1 μm / 0.5 μm. Filmed.
[0045]
Further, as shown in FIGS. 6D and 6E, a photosensitive layer is exposed on the silicon nitride film 2 having a plurality of processed portions, a mounting marker and optical semiconductor element lower conductor layer 8, and wirings 14a, 14b, 15a, and 15b. The film 3 is applied, and photolithography is performed using a mask on which the second mounting groove pattern is drawn, the opening 10 is formed, the silicon substrate surface is exposed, and all the photosensitive film 3 on the substrate is removed. Then, as shown in FIG. 5 (f), the pattern on the silicon substrate is anisotropically etched using tetramethylammonium hydroxide (TMAH) to form the waveguide mounting groove 11 on the silicon substrate. did.
[0046]
Next, as shown in FIG. 6G, the photosensitive film 3 is applied on the substrate 1 on which the mounting marker and optical semiconductor element lower conductor layer 8 and the waveguide mounting groove 11 are formed, and the optical semiconductor element mounting is performed. Photolithography is performed using a mask on which a solder bump pattern formed on the conductive conductor is drawn, and openings 12a and 12b are formed to expose the surface of the optical semiconductor element mounting conductor. Solder bumps 12 (weight ratio Au: Sn = 80: 20, thickness 2.5 μm) were formed using a beam evaporation method.
[0047]
Finally, as shown in FIGS. 6H and 6I, after all the photosensitive film 3 on the substrate surface is removed, the optical waveguide stopper rectangular groove 13 is formed by machining by dicing or the like, and then cut. It was. As a result, an optical mounting substrate for constructing an optical module having excellent optical coupling efficiency was obtained.
<Example 3>
Examples of the optical module M using the optical mounting substrate according to the present invention will be described below. As shown in FIGS. 4 and 5, the optical fiber 18 is mounted in the V groove 11 formed by etching to dispose the optical fiber 18 on the optical mounting substrate S, and the mounting is formed on the insulating film. A light emitting element 16 that is an optical semiconductor element and a light receiving element 17 for monitoring are aligned using a mounting marker and optical semiconductor mounting conductor (not shown) through solder bumps 12 formed on the conductor, respectively, Further, these optical semiconductor elements 16 and 17 are connected to the driving conductors 15a and 15b by bonding wires (not shown) so that the light coupling element 16 and the optical fiber 18 can be optically coupled. In the figure, reference numeral 20 denotes a lead which can be connected to an external electric circuit.
[0048]
In this way, so-called passive alignment is realized in which optical coupling can be performed with high accuracy simply by mounting the optical semiconductor elements 16 and 17 such as semiconductor laser elements on the solder bumps 12 on the mounting marker and optical semiconductor mounting conductor on the substrate 1. The completed optical module M is completed. The optical module M may be configured such that the whole is resin-molded by covering a lid (not shown), or the whole is resin-molded without covering the lid. Further, the optical semiconductor elements 16 and 17 may be provided with light emitting elements and / or light receiving elements such as LED elements and PD elements instead of the semiconductor laser elements.
[0049]
【The invention's effect】
As described above in detail, according to the present invention, in the optical mounting substrate on which the optical waveguide and the optical semiconductor element are mounted, the insulating film is not peeled off and from the recess formed by the single-layer insulating film. It is possible to prevent the molten solder from protruding to other areas. This eliminates the problem that the solder layer is short-circuited with other metal portions.
[0050]
  Also, mounting grooves for mounting optical waveguides and mounting markers and conductors for mounting optical semiconductor elementsWhenA mask for forming an opening for a mounting groove pattern and a mask for forming a conductor pattern for mounting an optical semiconductor element that also serves as a mounting marker for the optical semiconductor elementWhenAre the sameAndIn other words, each pattern is on the same mask, mounted on the optical waveguide formed using thisGrooveAnd mounting marker and conductor for mounting optical semiconductor elementsWhenHas no relative displacement, optical semiconductor element and optical waveguideWhenCan be mounted with high accuracy. Thereby, it is possible to provide an optical module having excellent optical coupling efficiency and an optical mounting substrate for constituting the optical module.
[Brief description of the drawings]
FIG. 1 shows the present invention.OkeIt is a top view which shows typically one Embodiment of the optical mounting board | substrate which is.
FIG. 2 is a partial end view taken along line BB in FIG.
FIGS. 3A to 3I are views for explaining an example of a manufacturing process of an optical mounting substrate according to the present invention, and are partial end views along line AA in FIG.
FIG. 4 shows the present invention.OkeIt is a top view which shows typically one Embodiment of the optical module using the optical mounting board | substrate.
FIG. 5 shows the present invention.InIt is a side view which shows typically one Embodiment of the optical module using an optical mounting board | substrate.
6A to 6I are diagrams for explaining another example of the manufacturing process of the optical mounting substrate according to the present invention, and are partial end views taken along line AA in FIG.
FIG. 7 is a top view schematically showing one embodiment of a conventional optical mounting substrate..
FIG. 8 is a cross-sectional view schematically showing one embodiment of a conventional optical mounting substrate..
[Explanation of symbols]
1, 31: Substrate
2: Insulating film
3: Photosensitive film
4: Opening portion of first mounting groove pattern
5a, 5b: Openings of conductor pattern for mounting optical semiconductor element
6: First mounting groove pattern processing section
7a, 7b: Conductive pattern processing portion for mounting an optical semiconductor element
8, 35: Lower conductor layer (conductor layer) for mounting marker and optical semiconductor element
9a, 9b: Openings of conductor pattern for mounting optical semiconductor element
10: Opening portion of second mounting groove pattern
11, 36: Optical waveguide mountedGroove
12, 35: Solder bumps (solder layer) for mounting optical semiconductor elements
12a, 12b: Openings of solder bump patterns for mounting optical semiconductor elements
13: Optical waveguide stopper rectangular groove
14a, 14b, 15a, 15b: wiring
16, 17, 37: Optical semiconductor element
18, 38: Optical waveguide (optical fiber)
19: Optical package
20: Lead
32: First insulating film
33: Metal pad
34: Second insulating film
S: Optical mounting board
SS: Optical mounting board
M: Optical module

Claims (2)

A conductor layer and a solder layer are disposed in a recess of a single-layer insulating film on which a mounting groove for disposing an optical waveguide and an optical semiconductor element optically connected to the optical waveguide are disposed on a substrate. An optical mounting substrate in which a mounting conductor is formed by being sequentially laminated, and the mask for forming the mounting groove and the mask for forming the recess are the same, and the recess is aligned with the mounting groove. A manufacturing method of
Forming the insulating film on the upper surface of the substrate, and forming a photosensitive film having an opening of a first mounting groove pattern and an opening of a mounting marker and optical semiconductor element mounting conductor pattern on the insulating film;
Using the photosensitive film as a mask, the surface of the substrate is not exposed in the region exposed by the opening of the first mounting groove pattern and the opening of the mounting marker and conductor pattern for mounting an optical semiconductor element. Removing the step,
After removing the photosensitive film in the previous step, forming a photosensitive film having an opening for forming the mounting conductor in the processed portion of the mounting marker and optical semiconductor element mounting conductor pattern; and the mounting An etching step for making at least one side surface of the processed portion of the conductor pattern for mounting the marker and optical semiconductor element for an inclined surface,
Forming the conductor layer in the processed portion of the conductor pattern for mounting marker and optical semiconductor element mounting;
After removing the photosensitive film in the previous step, forming a photosensitive film having an opening of the second mounting groove pattern in the processed portion of the first mounting groove pattern;
Using the photosensitive film as a mask, removing the insulating film in the region exposed by the opening of the second mounting groove pattern so that the substrate surface is exposed;
Forming the mounting groove in a region where the substrate surface is exposed after removing the photosensitive film in the previous step;
Forming a photosensitive film having an opening for forming a solder bump as the solder layer on the conductor layer;
Forming the solder bump on the conductor layer using the photosensitive film as a mask;
A step of forming an optical waveguide stopper rectangular groove after removing all of the photosensitive film on the substrate surface;
The method of manufacturing an optical mount substrate, wherein Rukoto to have a. A step of disposing the light waveguide to the mounting groove of the optical mount substrate obtained by the manufacturing method of an optical mount substrate according to claim 1,
A step of disposing the optical semiconductor element to be optically connected to the optical waveguide on the mounting conductor
A method for manufacturing an optical module , comprising:

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