JP3745828B2 - Package for optical semiconductor devices - Google Patents

Description

【００１８】
なお、上記実施例は本発明を具体化した一例であって、本願発明の技術的範囲を限定するものではない。例えば、金属枠体および金属底板の材質は、それぞれコバールおよび銅−タングステン合金に限定されることはない。また、補強部の断面形状も上記実施例に限定されることはない。さらに、光ファイバを取り付ける窓枠には、種種の構造ものを適用できる。
【００１９】
【発明の効果】
以上説明したように本発明によれば、光半導体素子を搭載する金属底板と、前記金属底板と異なる材料からなる金属枠体とを有し、前記金属枠体が前記金属底板上に接合されて形成された光半導体素子用パッケージにおいて、金属底板は平板状をなし、金属枠体は、該金属枠体と一体に、かつ前記金属枠体の前記光半導体素子の光軸に平行な側壁の内側に突出して形成された補強部を有し、該補強部を含む金属枠体の下部において前記金属底板と接合されているため、金属底板に銅−タングステン合金のような難削材を用いても、金属底板の材料費を節減し、その加工費を低減することができるので、それにともない光半導体素子用パッケージのコストを低減することができるという優れた効果がある。
【図面の簡単な説明】
【図１】（ａ）〜（ｅ）はそれぞれ、本発明にかかる光半導体素子用パッケージの第１の実施例における金属枠体の平面図、正面断面図、正面図、側面断面図、側面図である。
【図２】（ａ）、（ｂ）はそれぞれ、上記第１の実施例における金属底板の側面図および平面図である。
【図３】（ａ）、（ｂ）はそれぞれ、上記光半導体素子用パッケージの第１の実施例の側面図および正面断面図である。
【図４】（ａ）〜（ｅ）はそれぞれ、本発明にかかる光半導体素子用パッケージの第２の実施例における金属枠体の平面図、正面断面図、正面図、側面断面図、側面図である。
【図５】（ａ）〜（ｃ）はそれぞれ、上記光半導体素子用パッケージの第２の実施例の側面図、正面断面図および側断面図である。
【図６】（ａ）、（ｂ）はそれぞれ、本発明にかかる光半導体素子用パッケージの第３の実施例の側面図および正面断面図である。
【図７】従来の光半導体素子用パッケージの斜視図である。
【図８】（ａ）〜（ｃ）はそれぞれ、従来の金属枠体と金属底板を接合した状態の側面図、正面断面図および側面断面図である。
【符号の説明】
１１、２１、３１ 光半導体素子用パッケージ
１２、２２、３２ 金属枠体
１２ａ、２２ａ、２２ｂ、３２ａ 補強部
１２ｂ、２２ｃ 窓枠
１３ 金属底板
１３ａ ネジ穴[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical semiconductor element package that accommodates an optical semiconductor element used in an optical communication device or the like.
[0002]
[Prior art]
FIG. 7 shows an example of a package for an optical semiconductor element that includes a semiconductor laser element, a photodiode, or the like inside and is used in an optical communication device or the like. In general, the optical semiconductor element package 1 includes, as main components, a metal frame 2, a ceramic terminal 3, a metal bottom plate 4, leads 5, a seal ring 6, and a window frame 7 to which an optical fiber is attached.
[0003]
The metal frame 2 forms the outer shape of the package 1 for optical semiconductor elements, and has a role as a base material for housing internal components and joining the ceramic terminals 3 and optical fibers. The metal frame 2 is usually made of an Fe—Ni—Co alloy (commonly known as Kovar).
[0004]
The metal bottom plate 4 forms a bottom portion of the optical semiconductor element package 1 and has a function of efficiently dissipating heat generated inside the optical semiconductor element package 1 to the outside. This function is extremely important because the characteristics of the optical semiconductor element to be mounted are temperature-dependent, and therefore it is necessary to keep the optical semiconductor element at a constant temperature.
The metal bottom plate 4 is usually made of a copper-tungsten alloy having good heat dissipation, and has a mounting portion 4a on which a cooling element for cooling the optical semiconductor element disposed at the center of the upper surface is mounted. Further, screw holes 8 for attaching the optical semiconductor element package 1 to an external member are provided at both ends of the metal bottom plate 4.
When the metal bottom plate 4 is brazed to the metal frame 2 and generally silver brazed to assemble the optical semiconductor element package 1, the bottom surface of the metal bottom plate 4 is warped due to the difference in thermal expansion coefficient. In this state, when the optical semiconductor element package 1 is fixed to the external member with screws using the screw holes 8, the warpage is corrected, and the optical fiber attached to the optical axis of the semiconductor laser element and the window frame 7, for example, The relative position with respect to (not shown) will shift | deviate and it will lead to the fall of the coupling efficiency of a laser beam.
Therefore, as shown in FIGS. 8A to 8C, the thickness of the metal bottom plate 4 near the screw holes 8 is made thinner than the joint portion with the metal frame 2, so that the metal bottom plate in the metal frame 2 is formed. 4 is prevented from being deformed. Furthermore, in order to meet the demand for thinning the outer shape, the thickness of the mounting portion 4a is made thinner than the other portions so as to keep the overall height of the optical semiconductor element package 1 low.
[0005]
The ceramic terminal 3 is usually made of a multilayer alumina ceramic or the like, and is joined to the metal frame 2 by a brazing material such as silver brazing.
[0006]
The assembly for the optical semiconductor element package 1 is performed as follows. That is, a cooling element is attached to the mounting portion 4a of the metal bottom plate 4, an optical semiconductor element or the like is attached to the upper part, the ceramic terminal 3 and each element are connected by a bonding wire, and a lid is attached to the seal ring 6 so as to be airtight. Seal.
[0007]
[Problems to be solved by the invention]
However, in order to form the metal bottom plate 4 described above, a thick plate material with small warpage is processed to thin the mounting portion 4a, and the screw hole 8 is processed with a small plate thickness. And it is necessary to perform various processing. However, the copper-tungsten alloy constituting the metal bottom plate 4 is an expensive material and is known as a difficult-to-cut material, and its processing cost is very high. Thus, since the material cost and the processing cost are very high, the metal bottom plate 4 made of a copper-tungsten alloy has a problem that it becomes a great barrier to the cost reduction of the package for optical semiconductor elements.
[0008]
[Means for Solving the Problems]
The present invention has been made to solve the above problems, and has a metal bottom plate on which an optical semiconductor element is mounted and a metal frame made of a material different from the metal bottom plate, and the metal frame is on the metal bottom plate. In the package for optical semiconductor elements formed by bonding to the metal frame, the metal bottom plate has a flat plate shape , and the metal frame is integrated with the metal frame and parallel to the optical axis of the optical semiconductor element of the metal frame. It has a reinforcing part that protrudes from the inside of the side wall, and is joined to the metal bottom plate at the lower part of the metal frame including the reinforcing part .
[0009]
As described above, when the reinforcing portion is provided inside the joint portion of the metal frame body with the metal bottom plate, the optical semiconductor element package is screwed to the external member at the metal bottom plate portion, and the metal bottom plate of the screw fastening portion is fixed. Even if the warp is corrected, the metal bottom plate in the metal frame body portion is not deformed, so that the metal bottom plate can be constituted by a thin flat plate.
Therefore, even if a difficult-to-cut material such as a copper-tungsten alloy is used as the material for the metal bottom plate, it does not require much time for cutting, so that the processing cost can be suppressed. On the other hand, the metal frame made of Kovar or the like is provided with a reinforcing portion, which increases the processing cost, but the degree is slight. For example, the metal frame can be manufactured at a relatively low cost if it is formed in a near net shape by a known metal injection molding.
In addition, when a reinforcement part is provided in a metal frame, there also exists an advantage that a deformation | transformation becomes small at the time of sintering after injection molding, and finishing processing becomes easy.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
(First embodiment)
1A to 1E are a plan view, a front cross-sectional view, a front view, a side cross-sectional view, and a side view, respectively, of a metal frame of a first embodiment of an optical semiconductor element package according to the present invention. . FIGS. 2A and 2B are a side view and a plan view of the metal bottom plate of the same embodiment, respectively. Furthermore, Fig.3 (a), (b) is the side view and front sectional drawing of the same embodiment, respectively.
In the present embodiment, the metal frame 12 is made of Kovar having a thickness of 1 mm, a near net shape is formed using a metal injection molding method, and is machined into the shape shown in FIG. A joint portion of the metal frame 12 and the metal bottom plate 13 has a substantially right-angled quadrilateral shape. In the figure, 12a is a reinforcing part having a substantially right-angled quadrilateral section, and is provided on the inner side and the lower end of the metal frame 12 in the longitudinal direction. Reference numeral 12b denotes a window frame for fixing an optical fiber (not shown). In FIG. 1, details of the window frame are omitted.
The metal bottom plate 13 is a flat plate obtained by machining a copper-tungsten alloy, provided with screw holes 13a for attachment to external members at both ends, and Ni plated on the surface.
[0011]
The optical semiconductor element package 11 is assembled by first joining the metal frame 12, the metal bottom plate 13, the ceramic terminal (not shown), the sealing (not shown), and the lead (not shown) to the joint portion with silver solder ( A BAg-8) foil was sandwiched using a carbon jig, fixed and held, heated to about 810 ° C. by a continuous belt furnace, and silver brazed to form an assembly member. Thereafter, Au / Ni plating was applied to the surface.
[0012]
(Second Embodiment)
4A to 4E are a plan view, a front cross-sectional view, a front view, a side cross-sectional view, and a side view, respectively, of the metal frame of the second embodiment of the package for optical semiconductor elements according to the present invention. . In the present embodiment, the metal bottom plate is the same as that of the first embodiment shown in FIG. 5A to 5C are a side view, a front sectional view, and a side sectional view, respectively, of the embodiment. In FIG. 4, details of the window frame are omitted.
In the optical semiconductor device package 21 of the present embodiment, the joint portion between the metal frame 22 and the metal bottom plate 13 has a substantially rectangular shape. The metal frame 22 is provided with reinforcing portions 22a at the inner side and the lower end in the longitudinal direction, and is provided with reinforcing portions 22b at the inner side and the lower end in the width direction. The reinforcing portions 22a and 22b have a substantially rectangular shape in cross section. Reference numeral 22c denotes a window frame for fixing an optical fiber (not shown). Others are the same as in the first embodiment.
[0013]
(Third embodiment)
FIGS. 6A and 6B are a side view and a front sectional view, respectively, of a third embodiment of the package 31 for optical semiconductor elements according to the present invention. In the present embodiment, the metal bottom plate is the same as that of the first embodiment shown in FIG.
In the present embodiment, the metal frame 32 is provided with reinforcing portions 32 a on the inner side and the lower end in the longitudinal direction of the metal frame 32. The reinforcing portion 32a has a substantially triangular cross section. Others are the same as in the first embodiment. In FIG. 6, details of the window frame are omitted.
[0014]
【Example】
In each of the embodiments described above, a sample of the package for an optical semiconductor element was manufactured by changing the size of the reinforcing portion. The metal frame was formed from Kovar having a thickness of 1 mm, and the metal bottom plate was formed from a copper tungsten alloy.
Example 1
This corresponds to the first embodiment.
As shown in FIG. 3, the reinforcement part 12a of the metal frame 12 is provided in the inner side of a longitudinal direction, and the lower end. The metal frame 12 has a length L of 20.83 mm and a width W of 12.7 mm. Samples 1a to 1c shown in Table 1 were manufactured by changing the thickness T and width X of the reinforcing portion 12a and the thickness t of the metal bottom plate 13 made of a copper-tungsten alloy.
On the surface plate of the above sample, the warpage of the bottom surface was measured with a thickness gauge, and it was confirmed that the warpage was 30 μm or less. An optical semiconductor element and an optical fiber were attached to these samples, and the sample was fixed to the external member by screwing. Then, the optical semiconductor element was driven to measure the optical output from the optical fiber, and the change in the optical output before and after screwing was examined. As a result, all of the above samples were good with a change in light output of 5% or less.
In the present embodiment, the size of the cross section of the reinforcing portion 12a is not limited to the above sample. For example, as shown in FIG. 3, the metal frame 12 has a substantially rectangular shape with a thickness f (f ≦ 1.5 mm) and a length in the longitudinal direction L (10 mm ≦ L ≦ 30 mm), and its reinforcing portion 12a. Is provided in the longitudinal direction, and may have a thickness T (T ≧ 2t or T ≧ 1.5 mm) and a width X (X ≧ 0.05 L).
[0015]
(Example 2)
This corresponds to the second embodiment.
As shown in FIG. 5, the reinforcement part 22a of the metal frame 22 is provided at the inner side and the lower end in the longitudinal direction, and the reinforcement part 22b is provided at the inner side and the lower end in the width direction. The length L and width W of the metal frame 12 are the same as those in the first embodiment. By changing the thickness T and width X of the reinforcing portion 22a, the thickness T and width Y of the reinforcing portion 22b, and the thickness t of the metal bottom plate 13 made of a copper-tungsten alloy, samples 2a to 2c shown in Table 1 were obtained. Produced. About these samples, the change of the optical output was investigated similarly to Example 1. FIG. As a result, all of the above samples were good with a change in light output of 5% or less.
In the present embodiment, the size of the cross section of the reinforcing portion 22a is not limited to the above sample. For example, as shown in FIG. 5, the metal frame 22 has a thickness f (f ≦ 1.5 mm), a length in the longitudinal direction L (10 mm ≦ L ≦ 30 mm), and a width W (5 mm ≦ W ≦ 15 mm). The reinforcing portion 22a is provided in the longitudinal direction and the width direction, and has a thickness T (T ≧ 2t or T ≧ 1.5 mm), a longitudinal width X (X ≧ 0.045L), and a width. The width Y in the direction (Y ≧ 0.07W) may be used.
[0016]
Example 3
This corresponds to the third embodiment.
As shown in FIG. 6, the reinforcing portion 32 a of the metal frame 32 has a triangular cross section and is provided on the inner side and the lower end in the longitudinal direction. The length L and width W of the metal frame 32 are the same as those in the first embodiment. Samples 3a to 3c shown in Table 1 were prepared by changing the thickness T of the reinforcing portion 32a, the cross-sectional area S, and the thickness t of the metal bottom plate 13 made of a copper-tungsten alloy. About these samples, the change of the optical output was investigated similarly to Example 1. FIG. As a result, all of the above samples were good with a change in light output of 5% or less.
In the present embodiment, the size of the cross section of the reinforcing portion 32a is not limited to the above sample. For example, the metal bottom plate 13 is made of a copper-tungsten alloy plate having a thickness t, and the metal frame has a substantially rectangular shape with a thickness f (f ≦ 1.5 mm) and a length in the longitudinal direction L (10 mm ≦ L ≦ 30 mm). The reinforcing part is provided in the longitudinal direction, and the cross-sectional area S may be S ≧ 0.095 · t · L.
[0017]
[Table 1]

[0018]
In addition, the said Example is an example which actualized this invention, Comprising: The technical scope of this invention is not limited. For example, the materials of the metal frame and the metal bottom plate are not limited to Kovar and copper-tungsten alloy, respectively. Further, the cross-sectional shape of the reinforcing portion is not limited to the above embodiment. Furthermore, various types of structures can be applied to the window frame to which the optical fiber is attached.
[0019]
【The invention's effect】
As described above, according to the present invention, the metal bottom plate on which the optical semiconductor element is mounted and the metal frame body made of a material different from the metal bottom plate , the metal frame body is bonded onto the metal bottom plate. In the formed package for optical semiconductor elements, the metal bottom plate has a flat plate shape , and the metal frame is integrated with the metal frame and inside the side wall parallel to the optical axis of the optical semiconductor element of the metal frame. Since the metal bottom plate is joined to the metal bottom plate at the lower part of the metal frame including the reinforcement portion, a difficult-to-cut material such as a copper-tungsten alloy may be used for the metal bottom plate. Since the material cost of the metal bottom plate can be reduced and the processing cost can be reduced, the cost of the optical semiconductor device package can be reduced accordingly.
[Brief description of the drawings]
FIGS. 1A to 1E are a plan view, a front cross-sectional view, a front view, a side cross-sectional view, and a side view, respectively, of a metal frame in a first embodiment of an optical semiconductor device package according to the present invention. It is.
FIGS. 2A and 2B are a side view and a plan view, respectively, of a metal bottom plate in the first embodiment.
FIGS. 3A and 3B are a side view and a front sectional view, respectively, of the first embodiment of the package for an optical semiconductor element.
FIGS. 4A to 4E are a plan view, a front cross-sectional view, a front view, a side cross-sectional view, and a side view, respectively, of a metal frame in a second embodiment of an optical semiconductor device package according to the present invention. It is.
FIGS. 5A to 5C are a side view, a front cross-sectional view, and a side cross-sectional view, respectively, of a second embodiment of the optical semiconductor element package.
FIGS. 6A and 6B are a side view and a front sectional view, respectively, of a third embodiment of the package for optical semiconductor elements according to the present invention.
FIG. 7 is a perspective view of a conventional package for optical semiconductor elements.
FIGS. 8A to 8C are a side view, a front cross-sectional view, and a side cross-sectional view, respectively, illustrating a state in which a conventional metal frame and a metal bottom plate are joined together.
[Explanation of symbols]
11, 21, 31 Optical semiconductor element package 12, 22, 32 Metal frame 12a, 22a, 22b, 32a Reinforcement portion 12b, 22c Window frame 13 Metal bottom plate 13a Screw hole

Claims (2)

An optical semiconductor device package comprising: a metal bottom plate on which an optical semiconductor element is mounted; and a metal frame made of a material different from the metal bottom plate , wherein the metal frame is joined to the metal bottom plate. The bottom plate has a flat plate shape , and the metal frame has a reinforcing portion formed integrally with the metal frame and protruding inside the side wall of the metal frame parallel to the optical axis of the optical semiconductor element. A package for an optical semiconductor element, wherein the package is joined to the metal bottom plate at a lower portion of a metal frame including the reinforcing portion . The metal frame further includes a reinforcing portion formed integrally with the metal frame and protruding inside a side wall perpendicular to the optical axis of the optical semiconductor element of the metal frame. 2. The metal bottom plate is joined at a lower portion of a reinforcing portion that protrudes inside a parallel side wall and a reinforcing portion that protrudes inside a side wall perpendicular to the optical axis. The package for optical semiconductor elements described.

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