Patent ID: 12248181

DESCRIPTION OF EMBODIMENTS

Hereinafter, optical modules according to some embodiments of the present invention will be described in detail with reference to the drawings.

First Embodiment

FIG.2is a schematic diagram illustrating a basic structure of an optical module600A according to a first embodiment of the present invention.FIG.2(a)is a top view of the optical module600A.FIG.2(b)is a side view of the optical module600A.FIG.2(c)is an end view of the optical module600A taken along line IIc-IIc inFIG.2(a).

Referring toFIGS.2(a) to2(c), the optical module600A also has a structure in which an optical device100with an optical fiber300is attached to and mounted on a fiber holding carrier400having a tabular base. The optical device100incorporates an optical IC chip200, and the optical fiber300is optically coupled to the optical IC chip200so as to be connected and held. In addition, a pair of wall portions410is erected on the upper surface side of the fiber holding carrier400so as to face each other in the vicinity of long side edges thereof, and the optical device100is attached and fixed to the lower surface side of the fiber holding carrier400. Furthermore, a columnar protrusion420in which a dedicated pickup area EP1is secured is provided over the entire pickup area EP, which is for automatic suction by a mounting device and is a circular area substantially at the center of the upper surface of the fiber holding carrier400. The protrusion420has the same height in a direction perpendicular to the pickup area EP as the height of the pair of wall portions410, and has a top surface420ahaving a flat face on top of the height, and the top surface420aserves as the dedicated pickup area EP1.

That is, in the optical module600A, as illustrated inFIG.2(c), the top surface420aof the protrusion420is used as the pickup area EP1substituted for the existing pickup area EP. The pickup area EP1is positioned directly above and has the same area as the pickup area EP on the upper surface of the fiber holding carrier400. The top surface420aof the protrusion420therefore has a structure flat to a degree sufficient for pickup. That is, the pickup area EP1is also used for automatic suction and carrying of the optical module600A by the mounting device for surface mounting.

For attachment of the optical device100to the fiber holding carrier400, it is desirable to adopt an adhesive structure from viewpoints of ease of detachment and simplicity in configuration. Instead of the adhesive structure, a carrier, an optical device different from the optical device100, a mechanical clamp structure provided on another member, or the like may be applied.

Also in the optical module600A, the fiber holding carrier400is provided with the pair of facing wall portions410on a surface opposite to the surface to which the optical device100is attached. Thus, in a state after the optical device100has been attached to the fiber holding carrier400, an extra length of the optical fiber300extending from the optical device100is routed and held between the pair of wall portions410. At this time, the extra length including a tip portion of the optical fiber300is held in a storage area of the fiber holding carrier400by the restoring force caused by being pressed against the pair of wall portions410. In this holding state, the tip portion of the extra length of the optical fiber300can be disposed along the outer periphery of the protrusion420. As a result, the extra length including the tip portion of the optical fiber300is compactly held and fixed between the pair of wall portions410and the protrusion420.

In the optical module600A, due to the wall structures of the wall portions410and the protrusion420, even in a case where the optical fiber300is long, the extra length can be compactly held on the surface (upper surface) side of the fiber holding carrier400opposite to the surface to which the optical device100is attached. Thus, the top surface420aof the protrusion420at a central portion on the upper surface side of the fiber holding carrier400can be used as the pickup area EP1for automatic suction and carrying by the mounting device. Note that the pickup area EP1here is also sucked by a pickup tool or the like of the mounting device.

According to the optical module600A of the first embodiment, the columnar protrusion420is provided over the entire existing pickup area EP on the upper surface of the fiber holding carrier400, and the top surface420aof the protrusion420is used as the dedicated pickup area EP1. Thus, even in a case where the position where the optical fiber300is held is slightly shifted by a shock from outside, it is possible to effectively prevent the tip portion of the extra length of the optical fiber300from entering the dedicated pickup area EP1by an outer peripheral wall of the protrusion420. As a result, it is possible to sufficiently prevent the tip portion of the extra length of the optical fiber300from entering the dedicated pickup area EP1for automatic suction by the mounting device.

The optical module600A shows a case where the wall structure of the protrusion420has a columnar shape, but even in a case where the wall structure has another pillar shape such as a polygonal columnar shape, for example, it is possible to similarly prevent the extra length of the optical fiber300from entering the dedicated pickup area EP1. However, in order to avoid the optical fiber300from being bent with a curvature radius smaller than a minimum bending radius of the optical fiber300when the tip portion of the extra length of the optical fiber300is disposed along the outer periphery of the protrusion420, it is desirable that the protrusion420has a columnar shape.

Second Embodiment

FIG.3is a schematic diagram illustrating a basic structure of an optical module600B according to a second embodiment of the present invention.FIG.3(a)is a top view of the optical module600B.FIG.3(b)is a side view of the optical module600B.FIG.3(c)is an end view of the optical module600B taken along line IIIc-IIIc inFIG.3(a).

Referring toFIGS.3(a) to3(c), in the optical module600B, instead of the columnar protrusion420of the optical module600A, a hollow cylindrical protrusion430is provided in a peripheral portion of a pickup area EP. As illustrated inFIGS.3(a) and3(c), a dedicated pickup area EP2is secured inside the cylindrical protrusion430on the upper surface of a fiber holding carrier400. Since the dedicated pickup area EP2has a narrower area than the pickup area EP due to the presence of the hollow cylindrical protrusion430, the dedicated pickup area EP2needs to be sufficiently flattened so as to receive a suction force necessary for vacuum suction. That is, the dedicated pickup area EP2can be regarded as the pickup area EP corresponding to a hollow portion in the cylindrical protrusion430having a wall structure. The height of the hollow cylindrical protrusion430in a direction perpendicular to the pickup area EP is the same as the height of a pair of wall portions410. Other components of the optical module600B are similar to those of the optical module600A.

The hollow cylindrical protrusion430is effective when the fiber holding carrier400is manufactured by resin molding. The reason for this is that in a case where a wall structure constituted by the columnar protrusion420is formed by resin molding as in the case of the first embodiment, there is a possibility that a depression is formed on the top surface420aof the columnar protrusion420due to a difference in thickness between the wall structure of the protrusion420and the wall structure of the wall portions410. Then, in a case where a depression is formed on the top surface420aof the protrusion420, flatness is hindered, and a problem such as a suction failure or falling off during carrying may occur. On the other hand, the dedicated pickup area EP2is defined and formed by the presence of the hollow cylindrical protrusion430, and is hardly affected by formation of the protrusion430because of basically having an area obtained by reducing the existing pickup area EP.

Also in the case of the optical module600B, due to the wall structures of the wall portions410and the protrusion430, even in a case of a long optical fiber300, an extra length can be compactly held on the surface (upper surface) side of the fiber holding carrier400opposite to the surface to which an optical device100is attached. At this time, as for a tip portion of the extra length of the optical fiber300, the tip portion of the extra length of the optical fiber300is disposed along the outer periphery of the protrusion430. Thus, the hollow portion inside the protrusion430at a central portion on the upper surface side of the fiber holding carrier400can be used as the pickup area EP2for automatic suction and carrying by a mounting device. Note that the pickup area EP2here is also sucked by a pickup tool or the like of the mounting device.

According to the optical module600B of the second embodiment, the hollow cylindrical protrusion430is provided in the peripheral portion of the existing pickup area EP on the upper surface of the fiber holding carrier400, and the inside of the protrusion430is used as the dedicated pickup area EP2. Thus, even in a case where the position where the optical fiber300is held is slightly shifted by a shock from outside, it is possible to effectively prevent the tip portion of the extra length of the optical fiber300from entering the dedicated pickup area EP2by an outer peripheral wall of the protrusion430. As a result, it is possible to sufficiently prevent the tip portion of the extra length of the optical fiber300from entering the dedicated pickup area EP2for automatic suction by the mounting device.

Third Embodiment

FIG.4is a schematic diagram illustrating a basic structure of an optical module100C according to a third embodiment of the present invention.FIG.4(a)is a top view of the optical module100C.FIG.4(b)is a side view of the optical module100C.

Referring toFIGS.4(a) to4(c), in an optical module600C, instead of the protrusion430of the optical module600B, four protrusions440having a locally cylindrical shape separated by four cuts450are provided in a peripheral portion of a pickup area EP. As illustrated inFIG.4(a), a dedicated pickup area EP2is secured inside the protrusions440having a locally cylindrical shape on the upper surface of a fiber holding carrier400. Since the dedicated pickup area EP2also has a narrower area than the pickup area EP due to the presence of the protrusions440having a locally cylindrical shape, the dedicated pickup area EP2needs to be sufficiently flattened so as to receive a suction force necessary for vacuum suction. The height of the protrusions440having a locally cylindrical shape in a direction perpendicular to the pickup area EP is the same as the height of a pair of wall portions410. Other components of the optical module600C are similar to those of the optical module600A.

The protrusions440having a locally cylindrical shape are effective in a case where an optical device100is adhesively fixed to the fiber holding carrier400. The reason for this is that after surface mounting of the optical module600C, when the fiber holding carrier400is removed, it is possible to engage a protrusion of another jig with the cuts450and rotate the jig to remove the fiber holding carrier400. This allows for removal without manual work of a worker, and improves convenience. Note that the optical module100C having a configuration in which the four cuts450are provided in a cross shape and the four protrusions440having a locally cylindrical shape are provided has been described, but another number may be applied as long as the number allows for removal by rotation.

Also in the case of the optical module600C, due to the wall structures of the wall portions410and the protrusions440, even in a case of a long optical fiber300, an extra length can be compactly held on the surface (upper surface) side of the fiber holding carrier400opposite to the surface to which the optical device100is attached. At this time, as for a tip portion of the extra length of the optical fiber300, the tip portion of the extra length of the optical fiber300is disposed along the outer periphery of the protrusions440. Thus, a hollow portion inside the protrusions440at a central portion on the upper surface side of the fiber holding carrier400can be used as the pickup area EP2for automatic suction and carrying by a mounting device. Note that the pickup area EP2here is also sucked by a pickup tool or the like of the mounting device.

According to the optical module600C of the third embodiment, the protrusions440having a locally cylindrical shape are provided in the peripheral portion of the existing pickup area EP on the upper surface of the fiber holding carrier400, and the inside of the protrusions440is used as the dedicated pickup area EP2. Thus, even in a case where the position where the optical fiber300is held is slightly shifted by a shock from outside, it is possible to effectively prevent the tip portion of the extra length of the optical fiber300from entering the dedicated pickup area EP2by outer peripheral walls of the protrusions440. As a result, it is possible to sufficiently prevent the tip portion of the extra length of the optical fiber300from entering the dedicated pickup area EP2for component mounting.

Note that each embodiment shows a wall structure in which the extra length of the optical fiber300is pressed against the pair of wall portions410and compactly held, but instead of this, for example, a configuration may be adopted in which the extra length of the optical fiber300is held between groove structures. Moreover, in each embodiment, a claw structure may be provided to prevent the extra length including the tip portion of the optical fiber300from protruding outward beyond the top of the heights of the protrusions420and430, the protrusions440, and the pair of wall portions410. In this case, the claw structure is provided in a direction perpendicular to the height direction of the wall portions410. Furthermore, each embodiment exemplifies a configuration in which one long optical fiber300is connected to the optical IC chip200. Alternatively, a configuration may be adopted in which a plurality of the optical fibers300is connected to the optical IC chip200, and the extra length of each optical fiber300is held in an area for storing the extra length of each optical fiber300on the upper surface of the fiber holding carrier400. Note that examples of usage of the plurality of the optical fibers300in this case includes usages for input light, for transmission light, for reception light, and for input light of another wavelength for wavelength multiplexing.

In addition, in the first embodiment, a configuration in which the protrusion420is provided over the entire pickup area EP disposed at the central portion of the upper surface of the fiber holding carrier400has been described. In the second embodiment and the third embodiment, configurations in which the protrusion430and the protrusions440are provided on the peripheries of the similar pickup areas EP have been described. However, alternative structures can also be applied. For example, the pickup area EP may not be at the central portion depending on the design of the position where the optical device100is disposed on the fiber holding carrier400or the position of the center of gravity due to the structure of the fiber holding carrier400. A plurality of the pickup areas EP may be disposed depending on the shape of the pickup tool or process design. In such a case, it is possible to apply a configuration in which the protrusion420is provided over the pickup area EP that is not at the central portion or the entire pickup areas EP, or the protrusion430and the protrusions440are provided on the periphery of the pickup area EP or each pickup area EP.

Furthermore, in the embodiments, cases have been described in which the heights of the protrusions420and430and the protrusions440in the direction perpendicular to the pickup area EP are the same as the height of the wall portions410, but the heights may be greater than the height of the wall portions410. In addition, the height of the area in which the extra length of the optical fiber300is held on the upper surface of the fiber holding carrier400may be designed to be lower than the height of the wall portions410due to a claw structure or the like provided on the wall portions410. In such a case, it is sufficient if the heights of the protrusions420and430and the protrusions440in the direction perpendicular to the pickup area EP are designed to be greater than the height of the area in which the extra length of the optical fiber300is held.