JP2021144962A - Cap for optical element and optical semiconductor device - Google Patents

Abstract

To obtain an optical semiconductor device with high reliability.SOLUTION: A cap for optical element 2 comprises: a cylinder part 21 having a space for passing a light beam ejected from a light semiconductor element; a lens holding part 24 provided to one end side of the cylinder part 21 and holding a lens 4 for focusing the light beam toward a target; a collar part 23 extended toward an external side of a radial direction over a whole periphery of the other end side of the cylinder part 21; and a projection for welding a ring projection 22 formed so as to be projected toward the outer side of an axial direction from the collar part 23. The projection 22 provides a joint material layer 222 formed with the joint member which is welded, fluidized, softened, or reacted under a temperature lower than a fusing point of a base metal 221 and coating a base metal 221.SELECTED DRAWING: Figure 1

Description

The present application relates to a cap for an optical element and an optical semiconductor device.

In optical semiconductor devices for high output such as optical communication and video output, ring projection welding, which is a type of resistance welding, is used when airtightly joining a cap for an optical element with a lens (cap with a lens) to a substrate. There is. In ring projection welding, a protrusion (projection) provided on the brim of a cap for an optical element is brought into contact with a substrate, and electricity is applied while applying forging pressure through an electrode to melt the heat generated by current concentration at the protrusion. It is possible to join over the entire circumference by forging (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 58-18945 (page 1 right column-2 page upper left column, FIG. 1-2, page 2 upper right column-2 page lower left column, FIGS. 4-7)

However, in order to ensure airtightness, it is necessary to continue pressurizing as much as several hundred kPa even during energization, which is not suitable for a substrate having weak strength. In addition, the stem (corresponding to the substrate) used in optical semiconductor devices uses a glass material to insulate between the stem and the lead for energization, but if the pressure is strong, this glass material will be damaged. It may occur and airtight destruction may occur.

Of course, if the members are joined using a solder material, it is possible to avoid damage to the members, but the strength of the joining material is insufficient, and the positional relationship between the optical axis of the optical semiconductor element mounted on the substrate and the lens is deviated. Will occur, and reliability will decrease.

The present application discloses a technique for solving the above-mentioned problems, and an object of the present application is to obtain a highly reliable optical semiconductor device.

The cap for an optical element disclosed in the present application is provided on a tubular portion having a space for passing a light ray emitted from an optical semiconductor element, on one end side of the tubular portion, and for condensing the light ray toward a target. A lens holding portion that holds the lens, a brim portion that extends outward in the radial direction over the entire circumference of the other end side of the tubular portion, and a brim portion that projects outward in the axial direction from the brim portion. In addition, a projection for ring projection welding is provided, and the projection is formed of a bonding material that melts, fluidizes, softens, or reacts at a temperature lower than the melting point of the metal, and coats the metal. It is characterized in that a layer is provided.

According to the cap for an optical element disclosed in the present application, a joint portion responsible for mechanical coupling with a substrate and a joint portion responsible for maintaining airtightness can be formed in a composite manner, so that a highly reliable optical semiconductor device can be obtained. be able to.

1A and 1B are a bottom view and a cross-sectional view for explaining the configuration of the optical element cap according to the first embodiment, respectively. 2A and 2B are partial cross-sectional views showing the shape of the projection in the cap for the optical element according to the first embodiment, in which the covering range of the bonding material layer is different from each other. In FIGS. 3A and 3B, in the step of joining the optical element cap according to the first embodiment to the substrate, the optical element cap and the substrate are attached to the electrodes, respectively, and both electrodes are brought close to each other for bonding. It is sectional drawing which shows each state. 4A, 4B, and 4C each have a cross-sectional view of a state in which the projection of the optical element cap is pressed against the substrate in the step of joining the optical element cap according to the first embodiment to the substrate, and further energize. It is a cross-sectional view which shows the state at the time, and is a schematic diagram which shows the temperature distribution at the time of energization. 5A and 5B are partial cross-sectional views showing a projection configuration in which the covering range of the bonding material layer is different in the optical element cap according to the second embodiment. 6A and 6B are a side view and a bottom view for explaining the configuration of the optical element cap according to the third embodiment, respectively. 7A and 7B are partial cross-sectional views for explaining the configuration of projections in which unit projections are arranged at different intervals in the optical element cap according to the third embodiment. 8A to 8H and 8J are partial perspective views showing the configuration of unit projections having different shapes in the optical element cap according to the third embodiment. 9A to 8F are partial perspective views showing the configuration of unit projections having different shapes in the optical element cap according to the third embodiment. 10A to 10D are partial cross-sectional views showing a projection configuration in which the covering range of the bonding material layer is different in the cap for the optical element according to the third embodiment. It is a bottom view which shows the structure of the optical element cap which concerns on Embodiment 4. FIG.

Embodiment 1.
1 to 4 are for explaining the optical element cap according to the first embodiment and the optical semiconductor device manufactured by using the optical element cap, and FIG. 1 shows the bottom surface of the side to be joined to the substrate. It is a bottom view (FIG. 1A) of the optical element cap and a cross-sectional view taken along the line BB of FIG. 1A (FIG. 1B). Further, FIGS. 2A and 2B are enlarged partial cross-sectional views of the projection portion corresponding to FIG. 1B showing the shape of the projection in which the covering range of the bonding material layer is different in the cap for the optical element.

Then, FIG. 3 shows a state in which the cap with a lens and the substrate are attached to an annular electrode for ring projection and an electrode on a flat plate, respectively, in a process of joining a cap for an optical element holding a lens (a cap with a lens) to a substrate. It is a cross-sectional view (FIG. 3A) corresponding to FIG. 1B shown, and further is a cross-sectional view showing a state in which both electrodes are brought close to each other for bonding. Further, FIG. 4 is an enlarged cross-sectional view (FIG. 4A) of the contact portion between the projection and the substrate corresponding to FIG. 3B showing a state in which the projection is pressed against the substrate, and a cross-sectional view (FIG. 4B) showing a state when the power is further applied. ), And a schematic diagram (FIG. 4C) showing the temperature distribution around the contact portion when energized.

The optical element cap 2 according to the first embodiment is, for example, an integrally molded product of SUS, and as shown in FIG. 1 (FIGS. 1A and 1B), one end of a cylindrical portion 21 (in the figure, positive in the Z direction). An annular lens holding portion 24 is formed on the side) side, and a brim portion 23 is formed on the outer edge portion on the other end side. A lens 4 for condensing light emitted from an optical semiconductor element (not shown), which will be described later, is held in the center of the lens holding portion 24 to form a cap 1 with a lens. The brim portion 23 is provided with a projection 22 having a protrusion amount of, for example, 70 μm along the circumferential direction toward the outside in the axial direction (same as the negative side in the Z direction).

As a result, by joining to a substrate 5 (see FIG. 3) on which an optical semiconductor element such as a laser semiconductor element (not shown) is mounted, the light emitted from the optical semiconductor element is collected on a desired object such as an optical fiber. It can be made to shine. Further, by mounting a photodiode, a control circuit, or the like for measuring the intensity of emitted light, it is possible to form an optical semiconductor device that performs optical communication, video output, and the like. However, the configuration of the optical element cap 2 or the lens cap 1 up to this point is the same as that of a general optical element cap or lens cap 1.

As shown in FIG. 2A, the characteristic portion of the optical element cap 2 according to each embodiment of the present application is that the projection 22 has a bonding material layer 222 formed on the surface of the bare metal 221. The bonding material layer 222 is formed of a bonding material that undergoes a reaction such as melting, fluidization, softening, or thermosetting at a temperature lower than the melting point of the material constituting the base metal 221 constituting the cap 2 for an optical element. There is. As the bonding material, for example, solid or paste-like solder, low melting point glass, adhesive or the like can be applied. In this example, Sn-Ag-Cu solder having a melting point of 200 ° C. is vapor-deposited, dip or the like, and 20 A bonding material layer 222 having a thickness of ~ 50 μm was formed.

The coverage of the surface of the bare metal 221 by the bonding material layer 222 is not limited to the coating on both sides in the radial direction (r direction) as shown in FIG. 2A, and is in the radial direction as shown in FIG. 2B. One side (outer diameter side in the figure) may be covered. Further, in the subsequent embodiments including the first embodiment, the projection 22 is arranged in a circular shape, but the present invention is not limited to this, and the projection 22 may be a polygon, an ellipse, or the like, and has an airtight structure. It suffices if it is arranged in a closed figure (ring shape) that can be formed.

Next, the step of joining the above-mentioned cap 2 for an optical element (cap 1 with a lens) to the substrate 5 will be described with reference to FIGS. 3 and 4. First, as shown in FIG. 3A, the optical element cap 2 and the substrate 5 to be joined are installed on the upper electrode 8 and the lower electrode 9, respectively. The upper electrode 8 has a cylindrical shape, and the optical element cap 2 is inserted from the lens holding portion 24 side until the upper surface of the brim portion 23 touches the end surface 8e. At this time, the lens holding portion 24 and the lens 4 have a gap between the lens holding portion 24 and the upper electrode 8, but the outer peripheral surface of the tubular portion 21 and the inner peripheral surface of the upper electrode 8 are slidably in contact with each other. Therefore, the optical element cap 2 inserted into the upper electrode 8 is held in the upper electrode 8 even when the brim portion 23 is directed downward. On the other hand, the substrate 5 is basically positioned and placed on the lower electrode 9.

In this state, as shown in FIG. 3B, the upper electrode 8 is lowered toward the lower electrode 9 until the projection 22 contacts the joint surface 5j of the substrate 5, and the brim portion 23 is removed from the end surface 8e of the upper electrode 8. Forging pressure Lj is applied to the projection 22 through the projection 22. At this time, since the solder material forming the bonding material layer 222 is softer than the materials constituting the base metal 221 and the substrate 5, as shown in FIG. 4A, the forging pressure is lighter than the forging pressure (several hundred kPa) of normal projection welding. Even so, the bare metal 221 portion of the projection 22 breaks through the joint material layer 222. That is, even with a light forging pressure (for example, 150 kPa corresponding to about 60% of the normal forging pressure), the bare metal 221 portion of the projection 22 can be brought into contact with the joint surface 5j of the substrate 5.

When the upper electrode 8 and the lower electrode 9 are energized in this state, the current Cw concentrates on the contact portion Pc between the projection 22 and the joint surface 5j as shown in FIG. 4B. As shown in FIG. 4C, the Joule heat of the current Cw concentrated portion causes the temperature distribution in which the contact portion Pc becomes the highest temperature (white) in the projection 22 and the substrate 5 and becomes low temperature (black) as the distance increases. In FIG. 4C, the bonding material layer 222 portion of the projection 22 is excluded from the expression of the temperature distribution and is drawn with uniform hatching.

The situation shown in FIG. 4C shows the state of the rz plane at a certain angle (θ) in the circumferential direction, but the state does not necessarily occur uniformly over the entire circumference. However, even in general ring projection welding, the part softened by heat generation is further crushed by forging pressure and becomes hot, and the resistance value rises, so the resistance is smaller and it is not yet melted, another part in the circumferential direction. The current concentration point moves to. By repeating this, a uniform joint body can be formed in the circumferential direction by welding, and airtightness can be ensured.

However, for that purpose, it is necessary to raise the temperature from 1400 to 1500 ° C., which exceeds the melting point of the bare metal, over the entire circumference, and by applying the above-mentioned high forging pressure, a load is applied to the substrate, and there is a concern that the yield may decrease.

However, if the optical element cap 2 (or the cap 1 with a lens) according to each embodiment of the present application is used, a high forging pressure is applied so that the contact portion Pc undergoes a temperature rise history of 1400 ° C. or higher over the entire circumference. No need to call. Specifically, in the state shown in FIG. 4C, the heat from the contact portion Pc is also transferred to the bonding material layer 222 of the adjacent portion in the circumferential direction via the metal 221. At that time, for example, when the temperature reaches about 200 to 500 ° C., the bonding material layer 222 portion melts, and even if there is a gap between the base metal 221 and the substrate 5, the gap can be filled and brazed. ..

Of course, even in light forging, the contact portion Pc exceeding 1400 ° C. exists even if it is intermittent in the circumferential direction. Therefore, a strong bond between the base metal 221 and the substrate 5 by welding is maintained, and the mechanical holding force is comparable to that of general ring projection welding by high forging pressure. Further, as described above, even if the welded portion is intermittent, the joint material layer 222 fills the gap portion, so that airtightness can be ensured. Further, the positional relationship between the optical element cap 2 and the substrate 5 is maintained by the electrodes (upper electrode 8 and lower electrode 9), and there is no deviation. That is, a highly reliable optical semiconductor device can be obtained by welding having excellent airtightness, mechanical strength, and dimensional accuracy without worrying about damage due to forging pressure Lj.

Embodiment 2.
In the first embodiment, the example in which the bare metal is covered with the bonding material layer up to the tip portion of the projection is shown, but the present invention is not limited to this. In the present embodiment, an example in which the bare metal is exposed at the tip portion will be described. 5A and 5B are partial cross-sectional views corresponding to FIG. 2 used in the description of the first embodiment showing the configuration of projections in which the covering range of the bonding material layer is different in the cap for the optical element according to the second embodiment. Is. The portion other than the covering range of the bonding material layer is the same as that of the first embodiment, and FIGS. 1, 3, and 4 used in the first embodiment are incorporated, and the description of the same portion will be omitted.

In the optical element cap 2 according to the second embodiment, as shown in FIGS. 5A and 5B, the bare metal 221 at the tip of the projection 22 (lower part in the drawing) is exposed from the bonding material layer 222. I did it. Note that, in FIG. 5A, the bonding material layers 222 are formed on both sides in the radial direction in the same manner as in FIG. 2A used for the explanation of the first embodiment, and in FIG. 5B, with FIG. 2B used for the explanation of the first embodiment. Similarly, an example in which the bonding material layer 222 is formed on one side (outside) in the radial direction is shown.

For example, when the entire surface of the projection 22 is covered with a bonding material layer 222 made of a hard substance, the bare metal 221 as described in FIG. 4A of the first embodiment breaks through the bonding material layer 222 and forms a contact portion Pc. There is a concern that joining may not be possible without reaching the situation of formation.

However, as in the second embodiment, the contact portion Pc between the bullion 221 and the substrate 5 can be easily formed by configuring the tip portion of the projection 22 to expose the bullion 221 in advance. can. Therefore, as described with reference to FIGS. 4B and 4C, the heat generated at the contact portion Pc between the bullion 221 and the substrate 5 melts the tip of the projection 22 and joins the substrate 5 at the same time through the bullion 221. It is transmitted to the bonding material layer 222. The heat causes the bonding material layer 222 to start melting, and the molten bonding material brazes the base metal 221 and the substrate 5. That is, since the tip of the bullion 221 of the projection 22 always forms a contact portion Pc with the substrate 5 to form a welded portion, a strong joint portion is surely formed, and the joint material of the joint material layer 222, or wax. It is possible to obtain higher bonding strength than when bonding with only materials.

Embodiment 3.
In the first and second embodiments, the tip of the projection is continuous in the circumferential direction, but the present invention is not limited to this. In the optical element cap according to the third embodiment, an example in which a plurality of unit projections in which at least the tip portions of the bare metal are separated are arranged in the circumferential direction to form the projection will be described.

6 to 10 are for explaining the configuration of the optical element cap according to the third embodiment, and FIG. 6 is a side view (FIG. 6A) and a bottom view (FIG. 6A) of the optical element cap (cap with lens). 6B), FIGS. 7A and 7B are partial cross-sectional views of the metal portion corresponding to the CC line of FIG. 6B for explaining the configuration of the projection in which the unit projections are arranged at different intervals. 8A to 8H, 8J, and 9A to 8F are partial perspective views in which only the unit projection portion with the tip end facing upward is drawn for explaining the configuration of the unit projection having different shapes. 10A to 10D are partial cross-sectional views corresponding to lines CC of FIG. 6B for explaining the configuration of projections in which the covering ranges of the bonding material layers are different from each other. The part other than the projection is the same as that of the first or second embodiment, and FIG. 2 to FIG. 4 used in the first embodiment or FIG. 5 used in the second embodiment is used to refer to the same part. The description will be omitted.

As shown in FIGS. 6A and 6B, the optical element cap 2 according to the third embodiment forms the projection 22 by arranging the unit projections 22i having separated tip portions in the circumferential direction. Each unit projection 22i has a quadrangular pyramid shape as shown in FIG. 8A, and is arranged so that the root portion is adjacent and the tip portion is separated as shown in FIG. 7A.

In this case, the contact portion Pc with the substrate 5 appears intermittently in the circumferential direction. However, as compared with the case where the tip portion is continuous in the circumferential direction, even if the flatness of the substrate 5 or the height of the tip portion of the projection 22 is uneven, the contact portion Pc appears regularly, so that it is mechanically Welded portions that form a strong joint can be formed evenly. Further, even if the contact portions Pc are scattered, the spacing (the length in the circumferential direction of the root portion) is regular, so that the bonding material layer 222 located between the contact portions Pc is evenly heated above the melting temperature. Can be done and airtightness can be ensured.

The unit projection 22i does not necessarily have to be adjacent to each other at the root portion. For example, as shown in FIG. 7B, the unit projection 22i may be arranged intermittently with an interval G22. Even in this case, since the interval (the circumferential length of the root portion + G22) is regular, the bonding material layer 222 located between the contact portions Pc can be evenly heated above the melting temperature, and the airtightness can be improved. You can be sure.

The shape of the unit projection 22i is not limited to the quadrangular pyramid shown in FIG. 8A. As shown in FIGS. 8A to 8H and 8J and 9A to 9F, the shape parallel to the brim 23 at the base is circular (8D to 8F) and polygonal. (FIGS. 8A-8C, 9A-9C, 9D-9C) A star-shaped polygon (FIGS. 8G-8H, 8J) may be used. Further, the pillar type (FIG. 8C, FIG. 8F, FIG. 8J, FIG. 9C, FIG. 9F) also has a cone shape (FIG. 8A, FIG. 8D, FIG. 8G, FIG. 9A, FIG. 9D) and a cone shape (FIG. 8B, FIG. 8E, 8H, 9B, 9E).

Further, the covering range of the bonding material layer 222 in the circumferential direction may be formed on the entire surface of the bare metal 221 with a uniform thickness as shown in FIG. 10A, which matches the drawing of FIG. 6, but is limited to this. There is no such thing. For example, as shown in FIG. 10B, the tip portion may be exposed. Alternatively, as shown in FIGS. 10C and 10D, the unit projection 22i may be covered so as to fill the gap, and at that time, the tip portion is covered as shown in FIG. 10C to obtain the appearance as shown in FIG. Alternatively, as shown in FIG. 10D, only the tip portion may be exposed. In either case, it is possible to evenly arrange the welded structure parts with high strength and ensure airtightness with the joining material.

Embodiment 4.
In the above-described first to third embodiments, an example in which the projection is formed for one round is shown. It is not limited to this. In the optical element cap according to the fourth embodiment, an example in which the projection is formed in a plurality of turns will be described.

FIG. 11 is for explaining the configuration of the optical element cap according to the fourth embodiment, and is a bottom view of the optical element cap (cap with lens). The parts other than the projection are the same as those in the first to third embodiments, and the drawings used in each embodiment are used for the parts other than the bottom view, and the description of the same parts will be omitted.

As shown in FIG. 11, the optical element cap 2 according to the fourth embodiment has a double ring projection 22 having an outer projection 22a and an inner projection 22b formed on the brim portion 23. This enables stronger bonding both mechanically and airtightly.

In the figure, a state in which the unit projection 22i is arranged in the circumferential direction is drawn, but it may be connected in a ring shape as in the first embodiment, and the covering range of the bonding material layer 222 is also described in each embodiment. It can be changed as appropriate as described in the form.

Although the present application describes an exemplary embodiment, the various features, aspects, and functions described in the embodiment are not limited to application to a specific embodiment, but are used alone. It can be applied to embodiments in or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted.

For example, for the bonding material layer 222, an example in which a solder material is used has been described, but other brazing materials, as well as solid or paste-like low melting point glass, adhesives, and the like may be used. In that case, the airtight structure is realized not only by brazing but also by adhesion or adhesion. Further, the base metal of the optical element cap 2 is not limited to SUS (for example, stainless steel such as 304, 316), and any other material may be used as long as it is a material to which projection welding can be applied.

As described above, according to the optical element cap 2 according to each embodiment, the tubular portion 21 having a space for passing the light beam emitted from the optical semiconductor element and the light beam are provided on one end side of the tubular portion 21. A lens holding portion 24 for holding a lens 4 for condensing light toward a target, a brim portion 23 extending outward in the radial direction (r direction) over the entire circumference of the other end side of the tubular portion 21, and a brim portion 23. A projection 22 for ring projection welding, which is formed so as to project outward from the brim 23 in the axial direction (z direction), is provided, and the projection 22 is melted at a temperature lower than the melting point of the base metal 221. It is formed of a bonding material that fluidizes, softens, or reacts, and is configured to be provided with a bonding material layer 222 that covers the base metal 221. Since the joint portion made of the bonding material responsible for holding can be formed in a composite manner, damage due to forging pressure can be suppressed, and an optical semiconductor device having high position accuracy and high reliability can be obtained.

If the base metal 221 is exposed at the tip of the projection 22, even if the hardness of the joint material layer 222 is high, the contact portion Pc between the base metal can be easily formed by light forging and reliably welded. A joint can be formed by.

If the bonding material layer 222 is configured to be continuously formed along the circumferential direction at the root portion of the projection 22, the bonding portion made of the bonding material constituting the bonding material layer 222 is formed on the entire circumference with the substrate 5. It is formed so as to fill the gap between the two, and an airtight structure can be formed more reliably.

If the projection 22 is formed by arranging a plurality of unit projections 22i in a ring shape, the contact portion Pc can be formed over the entire circumference at regular intervals, so that the welded structure portion can be formed evenly over the entire circumference and the contact portion 22 can be formed. Since the temperature can be uniformly raised between the parts Pc, an airtight structure made of a bonding material can be realized more reliably.

At that time, since the bonding material layer 222 is formed so as to fill the gaps between the plurality of unit projections 22i in the circumferential direction, the bonding portion made of the bonding material constituting the bonding material layer 222 is formed with the substrate 5 over the entire circumference. It is formed so as to fill the gap, and an airtight structure can be formed more reliably.

Since a plurality of projections (outer projection 22a and inner projection 22b) are formed concentrically as projections 22 on the brim portion 23, a hybrid structure of a joint portion by welding and a joint portion made of a joining material can be more reliably formed. It can be formed in multiple or triple layers.

Further, according to the optical semiconductor device according to each embodiment, the optical semiconductor device (not shown) is bonded to the substrate 5 on which the optical semiconductor element is mounted, and an airtight space for accommodating the optical semiconductor element is formed between the substrate 5 and the substrate 5. Since it is configured to include the above-mentioned cap 2 for an optical element, it is possible to form a composite of a joint portion by welding that is responsible for mechanical coupling with the substrate 5 and a joint portion that is made of a bonding material that is responsible for maintaining airtightness. It is possible to obtain an optical semiconductor device that suppresses damage to the substrate 5, has high positional accuracy for forming an optical path, and has high reliability.

1: Cap with lens, 2: Cap for optical element, 21: Cylindrical part, 22: Projection, 22i: Unit projection, 221: Bullion, 222: Bonding material layer, 23: Cylindrical part, 24: Lens holding part , 5: Substrate.

Claims (7)

A tubular portion having a space for passing light rays emitted from an optical semiconductor element,
A lens holding portion provided on one end side of the tubular portion and holding a lens for condensing the light beam toward a target.
A projection for ring projection welding, which is formed so as to extend outward in the radial direction over the entire circumference of the other end side of the tubular portion and to protrude outward in the axial direction from the brim portion. With
The projection is characterized by being provided with a bonding material layer that is formed of a bonding material that melts, fluidizes, softens, or reacts at a temperature lower than the melting point of the metal and that covers the metal. Element cap. The cap for an optical element according to claim 1, wherein the tip portion of the projection is exposed to the bare metal. The cap for an optical element according to claim 1 or 2, wherein the bonding material layer is continuously formed along the circumferential direction at the root portion of the projection. The optical element cap according to any one of claims 1 to 3, wherein the projection is formed by arranging a plurality of unit projections in a ring shape. The cap for an optical element according to claim 4, wherein the bonding material layer is formed so as to fill a gap between the plurality of unit projections in the circumferential direction. The cap for an optical element according to any one of claims 1 to 5, wherein a plurality of projections are concentrically formed on the brim portion as the projection. The optical element according to any one of claims 1 to 6, wherein a substrate on which the optical semiconductor element is mounted and an airtight space formed between the substrate and the substrate to accommodate the optical semiconductor element. cap,
An optical semiconductor device characterized by being equipped with.

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