JPH0713240Y2 - Package for semiconductor optical active devices - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an improvement of a package for a semiconductor optical active element in which a semiconductor light emitting / receiving element is mounted.

[Conventional technology]

The semiconductor optical active device package has a function to house semiconductor light emitting / receiving devices, etc. (hereinafter referred to as optical active device), and also improves the coupling efficiency between the optical active device for optical fiber communication and the optical fiber and assembling work. From the viewpoint of improving the property, a function capable of easily positioning the optical active element with respect to the coupling optical system (not shown) is required.

FIG. 3 (a) shows a conventional semiconductor optical active element package. In this semiconductor optical active element package, a package body 1 is provided with a positioning mark 6 for mounting an optical active element (not shown). In addition, the cap 7 shown in FIG. 3 (c) covering the optically active element is capped and welded.

The package body 1 is formed of a single metal into a substantially cylindrical shape, and a flange portion 2 that projects in the horizontal direction is provided around the entire lower portion of the peripheral surface thereof, and a through hole 3 is provided. It is drilled vertically.

Further, a lead wire 4 for grounding is hung and inserted, and a lead wire 4A for supplying a current to the optically active element is vertically inserted in the through hole 3 through a Kovar glass 5 which is an insulating material. ing.

The alignment mark 6 is formed in a convex shape by rotary cutting out of a metal rod or the like, is positioned at the center of the upper surface of the package body 1 with high accuracy, and has a function of indicating a fixed position of the optical active element. ing.

Further, the cap 7 is formed into a substantially cylindrical shape whose lower surface is opened from iron, Kovar, etc., which are excellent in workability, and an optical lens 8 is fitted in a flat hole in the center of the upper surface.
The lower part of the peripheral surface is curved and formed in the collar part 9 which overlaps with the flange part 2.

According to the above configuration, the optical active element is accurately positioned at the center of the outer diameter of the package body (the center of the inner diameter of the cap 7) only by mounting the optical active element on the alignment mark 6, so that a coupling not shown is provided. The optical active element can be easily positioned with respect to the optical axis of the optical system.

By the way, in consideration of the weldability with the cap 7, the package body 1 is preferably made of the same material as the cap 7 as much as possible.

However, iron or Kovar, which is the material of the cap 7, has a not so large thermal conductivity and the coefficient of thermal expansion, the dielectric constant, etc. are remarkably different from the coefficient of thermal expansion of the optically active element, so that the LED itself emits heat. When an optical active element composed of a laser diode or a laser diode is mounted on the package body 1, a large thermal stress acts on the optical active element, resulting in a significant decrease in reliability.

In addition, when high-speed response is required such as a high-speed light emitting diode or a composite element of a light receiving diode and an amplifier,
It is necessary to form the package body 1 from a material whose electric characteristics such as a dielectric constant have specific values.

Therefore, conventionally, as shown in FIGS. 3B and 3C, between the package body 1 and the optically active element, the thermal conductivity is large and the coefficient of thermal expansion is close to that of the optically active element. By interposing another component called heat sink 10,
The device is designed to reduce the thermal stress acting on the optically active element.

The heat sink 10 that performs this heat dissipation function is configured to have a diameter smaller than that of the package body 1, and an alignment mark 6 for mounting a semiconductor light emitting diode 11 that is an optically active element is provided at the center of the upper surface of the heat sink 10. The package body 1 is accurately positioned and placed on the center of the upper surface.

A bonding wire 12 is installed and connected between the bonding pad (not shown) of the semiconductor light emitting diode 11 and the top of the lead wire 4A.

The other parts are the same as those described with reference to FIG.

Therefore, in order to assemble the semiconductor optical active device package shown in FIGS.
The semiconductor light emitting diode 11 is accurately mounted on the package, then the cap 7 is inserted into the package body 1, and the optical lens 8
After matching the optical axis O ₂ of the optical axis O ₁ and the semiconductor light-emitting diode 11 (the coupling optics), the flange portion 2 of the package body 1, polymerized the flange portion 9 of the cap 7 may be welded .

According to the above configuration, since the heat sink 10 performs a heat dissipation action, the thermal stress acting on the semiconductor light emitting diode 11 can be reduced and the reliability can be maintained.

As described above, in the conventional semiconductor optical active device package shown in FIGS. 3B and 3C, the heat sink 10 is accurately placed on the central portion of the upper surface of the package body 1, and the light of the optical lens 8 is removed. The axis O ₁ is made to coincide with the optical axis O ₂ of the semiconductor light emitting diode 11.

[Problems to be solved by the device]

The conventional semiconductor optical active device package is configured as described above, and the heat sink 10 is accurately placed on the center of the upper surface of the package body 1 so that the optical axis O ₁ and the optical axis O ₂ are aligned with each other. However, even if the semiconductor light emitting diode can be accurately mounted on the alignment mark 6, it is very difficult to accurately mount the heat sink 10 on the center of the upper surface of the package body 1.

Accordingly, since the error upon mounting of the heat sink 10 is generated inexorably, it can not be matched exactly with the optical axis O ₂ of the optical axis O ₁ and the semiconductor light-emitting diode 11 of the optical lens 8,
It was extremely inconvenient for practical use.

The present invention has been made in view of the above, and an object of the present invention is to provide a package for a semiconductor optical active element in which the optical active element can be easily positioned with respect to the coupling optical system and the influence of thermal stress can be reduced. I am trying.

[Means for Solving the Problems]

The present invention provides a substantially cylindrical first member, and a substantially cylindrical second member that is configured to have a diameter larger than that of the first member and that is provided on the first member and that performs heat dissipation. An alignment mark which is provided on the upper surface of the second member and indicates a fixing position of the semiconductor element, and a flange portion which is provided on the peripheral surface of the first member and has a diameter larger than that of the second member. It is characterized by being provided. Further, a cap having a substantially cylindrical shape whose inner peripheral surface overlaps with the peripheral surface of the second member, and a flange portion provided on the peripheral surface of the cap and overlapping with the flange portion may be provided.

[Action]

According to the present invention, since the inner peripheral surface of the cap is positioned and overlapped with the outer peripheral surface of the second member and the collar portion is positioned and overlapped with the upper surface of the flange portion when fitted, the optical axis is aligned with the optical axis. The cap can be positioned very easily relative to it.

That is, even if an error inevitably occurs when the second member is placed, it can be expected that the optical axis of the optical lens and the optical axis of the semiconductor element will be accurately aligned, which is extremely convenient in practice.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2.
The semiconductor optical active element package according to the present invention includes a package body (first member) 1, a heat sink (second member) 10A, and a cap 7 firmly and integrally.

The package body 1 is formed into a substantially cylindrical shape having a diameter of 3.6 mm and a height of 1 mm by pressing from Kovar or the like, and a flange portion 2 having a thickness of 0.2 mm and a diameter of 6 mm is formed over the entire circumference at the lower part of its peripheral surface. The flange 2 is a heat sink.
It is designed to project horizontally more than 10A.

Further, the package body 1 is provided with a through hole 3 extending vertically.

Further, a lead wire 4 for grounding is hung down and inserted in the package body 1, and a lead wire 4A for supplying a current to the optically active element is inserted into the through hole 3 by Kovar glass (sealing). It is vertically inserted through the agent 5.

On the other hand, the heat sink 10A, which performs heat dissipation, is formed of copper-tungsten alloy or copper into a substantially cylindrical shape having a diameter (3.95 mm) larger than that of the package body 1 by cutting. A positioning mark 6 with a diameter of 1 mm and a height of 0.1 mm for mounting (semiconductor element) 11 is projected with high precision by rotary cutting using a lathe, etc. It is supposed to be placed.

Further, the heat sink 10A is provided with through holes 3A which are penetrated by the lead wires 4A so as to extend longitudinally according to the number of the through holes 3.

In addition, a bonding wire 12 is installed between the bonding pad (not shown) of the semiconductor light emitting diode 11 and the top of the lead wire 4 and electrically connected thereto. still,
The semiconductor light emitting diode 11 is made of an InP-based semiconductor material.

Further, the alignment mark 6 exposed in a convex shape is projected at the same time as the outer shape processing of the heat sink 10A.

Further, the cap 7 is formed into a substantially cylindrical shape whose lower surface is opened by pressing or drawing from Kovar, which is excellent in workability, and has an optical lens 8 located directly above the semiconductor light emitting diode 11 in a flat hole in the center of the upper surface. Has been fitted,
Further, the lower portion of the peripheral surface is curvedly formed in the flange portion 9 which overlaps with the upper surface of the flange portion 2.

As shown in FIG. 1, the diameter of the inner surface of the cap 7 is equal to or slightly larger than the outer diameter of the heat sink 10A (diameter 4 mm).

The optical lens 8 is fixed so that its optical axis passes through the center of the outer diameter of the cap 7 and is parallel to the outer surface of the cylindrical portion.

Furthermore, the contact surface of the flange portion 9 with respect to the upper surface of the flange portion 2 is formed to be curved so as to be perpendicular to the optical axis (not shown).

Therefore, when assembling the semiconductor optical active element package, first, the heat sink 10A is mounted on the package body 1 by silver brazing to position the through hole 3 and the through hole 3A.

At the time of this placement, the package body 1 excluding the flange portion 2
Be careful not to stick out from the outer shape of the heat sink 10A.

Next, the fixed package body 1 and heat sink 10A
The surface of the is finished by plating or the like, the lead wire 4A is inserted into the through hole 3 and the through hole 3A, the Kovar glass is sealed in the through hole 3 to fix the lead wire 4A, and then the lead wire 4 is attached to the package body 1. Is attached by soldering.

Next, the light emitting portion of the semiconductor light emitting diode 11 is die-bonded to the alignment mark 6 of the heat sink 10A,
The bonding pad of the semiconductor light emitting diode 11 and the top of the lead wire 4 are electrically connected by the bonding wire 12.

However, after that, by inserting the cap 7 into the fixed package body 1 and the heat sink 10A and fixing the flange portion 9 to the upper surface of the flange portion 2 by welding or the like, the package for the semiconductor optical active element can be assembled.

According to the above configuration, the heat sink 10A having the expanded diameter is inserted at the time of fitting.
Since the inner peripheral surface of the cap 7 is positioned and superposed on the outer peripheral surface of the cap, and the collar portion 9 is positioned and superposed on the upper surface of the flange portion 2 having the enlarged diameter, the cap 7 is extremely easy to position with respect to the optical axis. Can be positioned (centered).

That is, even if an error is inexorably occurs during placement of the heat sink 10A, can be expected to match exactly with the optical axis O ₂ of the optical axis O ₁ and the semiconductor light-emitting diode 11 of the optical lens 8,
It is extremely convenient for practical use.

Specifically, even if a positional deviation of 0.15 mm occurs when the package body 1 and the heat sink 10A are brazed with silver,
Since there is no positional deviation between the center of the heat sink 10A and the center of the cap 7, the semiconductor light emitting diode 11 is located at the center of the cap 7, in other words, on the optical axis of the optical lens 8.
Can be extremely easily positioned.

Further, since the heat sink 10A, the package body 1 and the cap 7 are respectively made of different materials, and the package body 1 and the cap 7 to be welded are respectively made of Kovar which is excellent in workability, a semiconductor light emitting diode is provided. It is possible to alleviate the thermal stress acting on 11, and it can be expected that the weldability of the cap 7 will be improved.

Then, by selecting the position of the flange portion 2 of the package body 1, the height of the heat sink 10A, or the height of the cap 7, the semiconductor light emitting diode 11 is placed at an appropriate position with respect to the optical lens 8, for example, the semiconductor light emitting diode. The laser light emitted from 11 can be condensed and fixed at a position where it becomes a parallel light flux.

In addition, in the above-mentioned embodiment, the package for the light emitting diode made of the semiconductor material has been described. However, an element that receives light such as a photo sensor and converts it into an electric signal, or a semiconductor that emits light in response to an applied electric signal The present invention can also be applied to so-called general optical active elements such as laser diodes.

Further, although the cylindrical heat sink 10A is shown in the above embodiment, it may be a polygonal heat sink 10A. In this case, the inner surface of the cap 7 needs to be polygonal as the heat sink 10A is polygonal. There is.

Further, the dimensions of the package body 1, the heat sink 10A, and the cap 7 are not limited to those in the above embodiment, and it is sufficient that the size relationship between the respective constituent members is satisfied.

Further, in the above-described embodiment, the state in which the cap 7 including the optical lens 8 is capped is explained, but the present invention can be applied even when such a cap 7 is not capped. In this case, the case where the outer shape of the heat sink 10A is directly inserted into a hole or the like positioned with respect to the coupling optical system and fixed is conceivable.

Further, although the cap 7 having the optical lens 8 has been described in the above embodiment, the same effect as the above embodiment can be expected even if the present invention is applied to the cap 7 having only the opening hole in which the optical lens 8 is omitted. .

Furthermore, although the heat sink 10A is made of a metal material in the above embodiment, it goes without saying that the heat sink 10A may be made of an insulating material.

[Effect of device]

As described above, according to the present invention, at the time of fitting, the inner peripheral surface of the cap is positioned and superposed on the outer peripheral surface of the second member, and the flange portion is positioned and superposed on the upper surface of the flange portion. The remarkable effect is that the cap can be extremely easily positioned with respect to the optical axis.

That is, even if an error inevitably occurs when the second member is mounted, it is only necessary to accurately provide the alignment mark at the center of the outer shape of the second member, and the optical axis of the optical lens and the optical element There is a remarkable effect that it can be expected that the axis and the axis are matched with each other very accurately, and that it is extremely convenient in practical use.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a semiconductor optical active device package according to the present invention, and FIG. 2 (a) is a sectional view showing a non-capped state of the semiconductor optical active device package according to the present invention. 2 and FIG. 2 (b) are sectional explanatory views showing a cap of a package for a semiconductor optical active element according to the present invention, and FIGS. 3 (a), (b) and (c) are conventional semiconductor optical active element packages. It is sectional explanatory drawing which shows. In the figure, 1 is a package body (first member), 2 is a flange portion, 3.3A is a through hole, 4A is a lead wire, 6 is a positioning mark, 7 is a cap, 8 is an optical lens, and 9 is a lens. Is a collar portion, 10 and 10A are heat sinks (second member), and 11 is a semiconductor light emitting diode (semiconductor element).

Claims (2)

[Scope of utility model registration request] 1. A substantially cylindrical first member, and a first member which is formed to have a diameter larger than that of the first member and is provided on the first member.
A substantially cylindrical second member that performs a heat dissipation action, an alignment mark that is provided on the upper surface of the second member and indicates a fixing position of the semiconductor element, and a second member that is provided on the peripheral surface of the first member.
A semiconductor optical active element package, comprising: a flange portion that is larger in diameter than the above member. 2. A substantially cylindrical first member, and a first member which is configured to have a diameter larger than that of the first member and is provided on the first member.
A substantially cylindrical second member that performs a heat dissipation action, an alignment mark that is provided on the upper surface of the second member and indicates a fixing position of the semiconductor element, and a second member that is provided on the peripheral surface of the first member.
Of the member of which the diameter is larger than that of the member, a cap of which the inner peripheral surface is substantially cylindrical and overlaps with the peripheral surface of the second member, and a cap which is provided on the peripheral surface of the cap and overlaps with the flange portion A package for a semiconductor optical active element, comprising: