JP7421316B2 - optical module - Google Patents

Description

The present invention relates to an optical module that optically couples an optical fiber and a photoelectric conversion element.

A conventional optical module is shown in Patent Document 1. As shown in FIG. 16, this optical module 100 includes a substrate 110 on which a photoelectric conversion element 102 is mounted, and an optical housing 120 that is fixed to the substrate 110 and accommodates the photoelectric conversion element 102 in an internal space 121. .

The optical housing 120 is made of a light-transmissive resin member. The optical housing 120 includes a lens 122 disposed opposite to the photoelectric conversion element 102, a light guiding section 123 forming an optical path of an optical signal passing through the lens 122, and a sleeve 124 provided at the other end of the optical path of the light guiding section 123. and has. Since the optical housing 120 is a resin member, it is fixed to the substrate 110 with an adhesive.

Japanese Patent Application Publication No. 2004-354452 Japanese Patent Application Publication No. 2007-171427

However, in the optical module 100 of the conventional example, the optical housing 120 is fixed to the substrate 110 with an adhesive, so when used in environments such as high temperature and high humidity, the adhesive deteriorates and peels off, and when the temperature changes. There is a possibility that the optical housing 120 may be displaced with respect to the substrate 110 due to expansion and contraction. In other words, there was a problem in that the reliability of the connection between the optical housing 120 and the substrate 110 was poor.

The present invention has been made in view of the problems of the prior art. An object of the present invention is to provide an optical module in which the connection of an optical housing to a substrate is highly reliable.

An optical module according to an aspect of the present invention includes a substrate on which a photoelectric conversion element is mounted, and an optical housing that is fixed to the substrate and accommodates the photoelectric conversion element in an internal space, and the optical housing has a light transmissive property. A resin member and a conductive metal member are integrally provided, and the resin member has a lens disposed opposite to the photoelectric conversion element and a light guide portion forming an optical path of an optical signal passing through the lens. The metal member includes a shielding plate portion surrounding the internal space and a terminal portion fixed to the substrate, and the optical housing includes at least a portion of the metal member embedded in the resin member. There is.

Preferably, in the optical housing, a portion of the metal member surrounding the inner space is embedded in the resin member, and a surface on the inner space side is covered with the resin member.

The resin member includes one having a sleeve for fixing the end portion of the optical fiber.

The resin member includes one having a mirror that reflects an optical signal in the light guide portion.

Preferably, a plurality of photoelectric conversion elements are mounted on the substrate, and the metal member has a partition plate portion that partitions between the plurality of photoelectric conversion elements.

Preferably, the substrate is provided with a positioning hole, and the metal member is provided with a positioning pin that is inserted into the positioning hole.

According to the present invention, it is possible to provide an optical module in which the connection reliability of the optical housing to the substrate is high.

1 is a plan view of an optical module, showing the first embodiment; FIG. FIG. 2 is a sectional view taken along line II-II in FIG. 1, showing the first embodiment. A first embodiment is shown, in which (a) is a plan view of an optical housing, and (b) is a plan view of a metal member. 3(a) is a sectional view taken along the line IVa--IVa in FIG. 3(a), and FIG. 3(b) is a sectional view taken along the line IVb--IVb in FIG. 3(b). It is a sectional view of an optical module, showing a first modification of the first embodiment. FIG. 7 is a plan view of an optical module, showing a second modification of the first embodiment. 7 is a sectional view taken along the line VII-VII of FIG. 6, showing a second modification of the first embodiment. FIG. It is a sectional view of an optical module, showing a third modification of the first embodiment. FIG. 7 is a plan view of an optical module according to a second embodiment. A second embodiment is shown, in which (a) is a cross-sectional view taken along the line Xa--Xa in FIG. 9, and (b) is a cross-sectional view taken along the line Xb--Xb in FIG. 2nd Embodiment is shown, (a) is a top view of an optical housing, (b) is a top view of a metal member, and (c) is a D arrow direction view of (b). 11(a) is a sectional view taken along the line XIIa-XIIa in FIG. 11(a), and FIG. 11(b) is a sectional view taken along the line XIIb-XIIb in FIG. 11(b). FIG. 7 is a plan view of an optical module, showing a first modification of the second embodiment. 14 is a sectional view taken along the line XIV-XIV in FIG. 13, showing a first modification of the second embodiment. FIG. It is a sectional view of an optical module, showing a second modification of the second embodiment. FIG. 2 is a cross-sectional view of an optical module, showing a conventional example.

Hereinafter, optical modules according to embodiments will be described in detail using the drawings. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

(First embodiment)
As shown in FIGS. 1 to 4, the optical module 1 according to the first embodiment includes a substrate 10 on which a photoelectric conversion element 2 and a drive circuit section 3 are mounted, and is fixed to the substrate 10 and has a photoelectric conversion element 2 inside. The light housing 20 is housed in a space 21.

The photoelectric conversion element 2 is a light receiving element, a light emitting element, or a light receiving and emitting element. The drive circuit section 3 includes a drive IC, an amplifier, a TIA (Transimpedance Amplifier), etc. for driving the photoelectric conversion element 2 .

The substrate 10 includes a flat base material 11 and wiring patterns 12 and 13 made of a conductive material arranged on the upper surface of the base material 11. The wiring patterns 12 and 13 are a ground wiring pattern 12 and a signal wiring pattern 13.

The optical housing 20 is integrally provided with a light-transmitting resin member 22 and a conductive metal member 30. The surfaces of the resin member 22 and the metal member 30 that are in contact with each other are in close contact with each other. The optical housing 20 is molded by insert resin molding using the metal member 30 as an insert material.

The resin member 22 used has low optical loss and can maintain mechanical properties under the usage environment. The resin member 22 includes a lens 23 disposed opposite to the photoelectric conversion element 2, a light guide portion 24 forming an optical path C (shown in FIGS. 2 and 4(a)) of an optical signal passing through the lens 23, and a light guide portion. 24 and a sleeve 25 provided on the other end side of the optical path. The lens 23 is a convex lens, and is formed on the inner surface in which the internal space 21 is formed. The light guide portion 24 is formed of a resin portion between the lens 23 and the sleeve 25. The optical path C of the light guide section 24 (shown in FIGS. 2 and 4(a)) is a straight path along the optical axis of the lens 23.

The sleeve 25 has a cylindrical shape that projects upward. A cylindrical interior is formed as a ferrule fitting hole 26 . A ferrule (not shown) fixed to the end of an optical fiber (not shown) is fitted into the ferrule fitting hole 26 .

The metal member 30 is made of stainless steel (SUS), aluminum, copper, or the like. The metal member 30 includes a shielding plate portion 31 surrounding the internal space 21 and a terminal portion 35 fixed to the substrate 10. At least a portion of the metal member 30 is embedded within the resin member 22. In the first embodiment, all parts of the shielding plate part 31 except the terminal part 35 are embedded in the resin member 22, and the surface on the inner space 21 side is almost completely covered with the resin member 22.

The shielding plate portion 31 is placed in a position to cover the upper surface of the internal space 21 , and is placed in a position to cover the quadrangular top plate portion 32 and four side surfaces of the internal space 21 , and covers each side of the top plate portion 32 . It has four side plate portions 33 that are more hanging down.

A light transmission hole 32a is provided at the center of the upper plate portion 32. The resin member 22 is filled inside the light transmission hole 32a. Thereby, the optical path C in the light guide section 24 is secured.

Each terminal portion 35 extends horizontally outward from the lower ends of the four side plate portions 33, respectively. The terminal portions 35 are provided at five locations in total. Each terminal portion 35 is exposed from the resin member 22 as described above. Each terminal portion 35 is placed on the ground wiring pattern 12 of the board 10 and soldered. Thereby, the metal member 30 is grounded.

According to the above configuration, the optical signal emitted from the photoelectric conversion element 2 passes through the lens 23, proceeds through the light guide section 24, passes through the ferrule (not shown), and is transmitted to the optical fiber (not shown). . Further, light emitted from an optical fiber (not shown) through a ferrule (not shown) travels through the light guide section 24 and is converted into convergent light by the lens 23 and collected by the photoelectric conversion element 2. In this way, the optical housing 20 optically couples the optical fiber (not shown) and the photoelectric conversion element 2.

As described above, the optical housing 20 according to the first embodiment includes the substrate 10 on which the photoelectric conversion element 2 is mounted, and the optical housing 20 that is fixed to the substrate 10 and accommodates the photoelectric conversion element 2 in the internal space 21. It is equipped with The optical housing 20 is integrally provided with a light-transmitting resin member 22 and a conductive metal member 30, and the resin member 22 passes through a lens 23 disposed opposite to the photoelectric conversion element 2 and It has a light guide section 24 that forms an optical path C of an optical signal. Furthermore, the metal member 30 has a shielding plate portion 31 surrounding the internal space 21 and a terminal portion 35 fixed to the substrate 10 , and the optical housing 20 has at least a portion of the metal member 30 inside the resin member 22 . It is buried.

Therefore, since the optical housing 20 is fixed to the substrate 10 with the metal member 30, it can be fixed with a fixing means that is more reliable in the usage environment than adhesives, has high environmental resistance, and is resistant to vibration. , mechanical reliability is improved. In the optical housing 20, since at least a part of the metal member 30 is embedded in the resin member 22, the linear expansion difference between the metal member 30 and the resin member 22 is suppressed from all directions at the buried location, and the linear expansion difference is suppressed from all directions. It suppresses peeling, has high environmental resistance, is resistant to vibration, and improves mechanical reliability. As described above, it is possible to provide an optical module 1 in which the connection reliability of the optical housing 20 to the substrate 10 is high.

Furthermore, since the optical housing 20 is an integral structure of a resin member 22 and a metal member 30 whose mechanical strength is stronger than that of the resin member 22, the optical housing 20 has high environmental resistance and is resistant to vibration due to this structure. High mechanical reliability.

Since the photoelectric conversion element 2 is surrounded by a conductive metal member 30, the negative effects of electromagnetic noise on the photoelectric conversion element 2 from the outside through the optical housing 20 can be avoided, and the negative effects of electromagnetic noise can be transmitted from the photoelectric conversion element 2 through the optical housing 20 to the outside. The negative effects of electromagnetic noise can be reduced. Similarly, the negative effects of electromagnetic noise on the drive circuit section 3 can be reduced.

In the first embodiment, the optical housing 20 has a portion of the metal member 30 surrounding the inner space 21 embedded in the resin member 22, and the surface on the inner space 21 side is covered with the resin member 22.

Therefore, since the linear expansion difference between the shielding plate part 31, which is a part that covers the internal space 21 of the metal member 30, and the resin member 22 is suppressed from all directions, peeling due to the linear expansion difference is suppressed, and mechanical reliability is improved. further improves.

The resin member 22 includes a sleeve 25 that is integral with the light guide section 24 and fixes an end portion of an optical fiber (not shown). Therefore, optical fibers (not shown) can be connected by means of ferrules (not shown).

(First modification of the first embodiment)
An optical module 1 according to a first modification of the first embodiment is shown in FIG. As shown in FIG. 5, the substrate 10 is provided with a plurality of positioning holes 14. The metal member 30 is provided with a plurality of positioning pins 36 that are inserted into each positioning hole 14 .

The other configurations are the same as those in the first embodiment, so redundant explanation will be omitted. Identical parts in the drawings are given the same reference numerals for clarity.

In the optical module 1 according to the first modification of the first embodiment, since the optical housing 20 is positioned at an appropriate position on the substrate 10, the photoelectric conversion element 2 mounted on the substrate 10 and the lens 20 of the optical housing 20 positioning can be easily and accurately performed. In addition, since it can be implemented using passive alignment, costs can be reduced.

(Second modification of the first embodiment)
An optical module 1 according to a second modification of the first embodiment is shown in FIGS. 6 and 7. As shown in FIGS. 6 and 7, two photoelectric conversion elements 2 are mounted on the substrate 10. As shown in FIGS. The metal member 30 of the optical housing 20 has a partition plate portion 37 that partitions between the two photoelectric conversion elements 2 .

The other configurations are the same as those in the first embodiment, so redundant explanation will be omitted. Identical parts in the drawings are given the same reference numerals for clarity.

In the optical module 1 according to the second modification of the first embodiment, crosstalk between the two photoelectric conversion elements 2 can be reduced by the partition plate portion 37.

In the second modification of the first embodiment, there are two photoelectric conversion elements 2, but when three or more photoelectric conversion elements 2 are arranged, a partition plate portion 37 is provided to partition each photoelectric conversion element 2. Place.

(Third modification of the first embodiment)
An optical module 1 according to a third modification of the first embodiment is shown in FIG. As shown in FIG. 8, the top plate portion 32 of the metal member 30 is embedded in the resin member 22 as in the first embodiment, but the four side plate portions 33 are different from the first embodiment. It is not embedded within the resin member 22. The four side plates are exposed to the outside with only one side in contact with the outer surface of the resin member 22.

The other configurations are the same as those in the first embodiment, so redundant explanation will be omitted. Identical parts in the drawings are given the same reference numerals for clarity.

In the optical module 1 according to the third modification of the first embodiment, the top plate portion 32 of the metal member 30 is embedded in the resin member 22, so that the top plate portion 32 where the metal member 30 is buried is Since the linear expansion difference with the resin member 22 is suppressed from all directions, peeling due to the linear expansion difference is suppressed, and mechanical reliability is improved.

(Second embodiment)
The optical module 1 according to the second embodiment is shown in FIGS. 9 to 12. The optical module 1 according to the second embodiment is different from the first embodiment in the configuration of the optical housing 20.

Similar to the first embodiment, the optical housing 20 is integrally provided with a light-transmitting resin member 22 and a conductive metal member 30, but the resin member 22 has a higher height than that of the first embodiment. The thickness T in the direction is large.

A V-shaped groove 27 is formed in the resin member 22 and opens on the upper surface. A mirror 40 is formed by the inclined surface of this one groove 27. The mirror 40 is placed directly above the lens 23 and is inclined at 45 degrees with respect to the optical axis of the lens 23. That is, in this second embodiment, the light guide section 24 is provided with a mirror 40 that reflects the optical signal, and the optical path of the optical signal is changed by 90 degrees by the mirror 40. The light guide portion 24 is formed of a resin portion between the lens 23 and one side surface of the resin member 22. The optical path C of the light guide section 24 (shown in FIGS. 10A and 12A) is a path consisting of a straight path along the optical axis of the lens 23 and a right-angled path changed by 90 degrees by the mirror 40.

The metal member 30 has a top plate portion 32 and four side plate portions 33, as in the first embodiment. The upper plate portion 32 is not provided with a light transmission hole as in the first embodiment. Instead, a rectangular hole 32b for forming the V-shaped groove 27 of the resin member 22 is formed in the upper plate portion 32.

In the second embodiment, the upper part of the shielding plate part 31 is embedded in the resin member 22, and the surface of the upper part of the shielding plate part 31 on the inner space 21 side is covered with the resin member 22. As in the first embodiment, the entire shielding plate portion 31 may be buried with the resin member 22.

One side plate portion 33 is provided with a light transmission hole 33a. The resin member 22 is filled inside the light transmission hole 33a. Thereby, the optical path C in the light guide section 24 is secured. The metal member 30 has terminal portions 35 extending only from the two opposing side plate portions 33 . That is, in the second embodiment, the terminal portions 35 are provided at only two locations.

In this second embodiment, as shown in FIGS. 9 and 10, an MT ferrule 42 to which an end of an optical fiber 41 is connected is arranged on one side of the optical housing 20.

The other configurations are the same as those in the first embodiment, so redundant explanation will be omitted. Identical parts in the drawings are given the same reference numerals for clarity.

Also in this second embodiment, for the same reason as the first embodiment, it is possible to provide an optical module 1 with improved mechanical reliability and with high connection reliability of the optical housing 20 to the substrate 10.

In the optical module 1 according to the second embodiment, the resin member 22 includes a mirror 40 that reflects an optical signal onto the light guide section 24. Therefore, the connection position of the optical fiber 41 can be freely installed at a position other than the optical axis of the lens 23.

(First modification of the second embodiment)
An optical module 1 according to a first modification of the second embodiment is shown in FIGS. 13 and 14. As shown in FIGS. 13 and 14, two photoelectric conversion elements 2 are mounted on the substrate 10. The metal member 30 of the optical housing 20 has a partition plate portion 37 that partitions between the two photoelectric conversion elements 2 . The mirror 40 is formed in a size that allows optical signals sent to the two photoelectric conversion elements 2 to be changed independently.

The other configurations are the same as those of the second embodiment, so redundant explanation will be omitted. Identical parts in the drawings are given the same reference numerals for clarity.

In the optical module 1 according to the first modification of the second embodiment, crosstalk between the two photoelectric conversion elements 2 can be reduced.

In the first modification of the second embodiment, there are two photoelectric conversion elements 2, but when three or more photoelectric conversion elements 2 are arranged, a partition plate portion 37 is provided to partition each photoelectric conversion element 2. Place.

(Second modification of second embodiment)
An optical module 1 according to a second modification of the second embodiment is shown in FIG. 15. As shown in FIG. 15, the substrate 10 is provided with a plurality of positioning holes 14. The metal member 30 is provided with a plurality of positioning pins 36 that are inserted into each positioning hole 14 .

The other configurations are the same as those in the second embodiment, so redundant explanation will be omitted. Identical parts in the drawings are given the same reference numerals for clarity.

In the optical module 1 according to the second modification of the second embodiment, since the optical housing 20 is positioned at an appropriate position on the substrate 10, the photoelectric conversion element 2 mounted on the substrate 10 and the lens 20 of the optical housing 20 positioning can be easily and accurately performed. In addition, since it can be implemented using passive alignment, costs can be reduced.

(Modified example)
In each embodiment and its modification, the metal member 30 of the optical housing 20 is fixed to the substrate 10 with solder, but it may also be fixed by laser welding using a YAG laser or the like, laser cladding (build-up welding), or the like.

In each embodiment and its variations, it is necessary to provide at least the light transmission hole 32a in the metal member 30, but if it is possible to reduce electromagnetic noise, holes or gaps may be provided in the metal member 30 as appropriate. good. Further, the metal member 30 may be mesh-shaped depending on EMC characteristics (electromagnetic compatibility characteristics).

Although this embodiment has been described above, this embodiment is not limited to these, and various changes can be made within the scope of the gist of this embodiment.

1 Optical module 2 Photoelectric conversion element 10 Substrate 14 Positioning hole 20 Optical housing 21 Internal space 22 Resin member 23 Lens 24 Light guiding portion 25 Sleeve 30 Metal member 31 Shielding plate portion 35 Terminal portion 36 Positioning pin 37 Partition plate portion 40 Mirror

Claims (4)

A substrate on which a photoelectric conversion element is mounted,
an optical housing fixed to the substrate and accommodating the photoelectric conversion element in an internal space;
The optical housing is integrally provided with a light-transmitting resin member and a conductive metal member,
The resin member includes a lens disposed opposite to the photoelectric conversion element, and a light guide portion forming an optical path of an optical signal passing through the lens,
The metal member has a shielding plate portion surrounding the internal space and a terminal portion fixed to the substrate,
The shielding plate portion is
a top plate portion that secures the optical path and covers an upper surface of the internal space;
a side plate portion hanging down from the top plate portion toward the substrate and covering a side surface of the internal space;
The optical module, wherein the entire shielding plate portion is embedded within the resin member. The optical module according to claim 1, wherein the resin member includes a sleeve for fixing an end portion of the optical fiber. 3. The optical module according to claim 1, wherein the resin member includes a mirror that reflects an optical signal on the light guide section. The substrate is provided with a positioning hole,
The optical module according to any one of claims 1 to 3, wherein the metal member is provided with a positioning pin that is inserted into the positioning hole.

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