JPH10275873A - Package for optical semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a ceramic frame against cracks due to brazing stresses by a structure, wherein the brazing stress is scattered to a large number of corners, when an optical fiber fixing member is jointed through a brazing material to the metallization layer of a ceramic frame. SOLUTION: This package for optical semiconductor element has a base 1 having a part 1a for mounting an optical semiconductor element S, a ceramic frame 2 fixed to the base 1 and having a through-hole 2a in the sidewall with a metalization layer 5 being applied to the periphery thereof, an optical fiber fixing member 4 having a tubular part 4b provided with a flange 4a, a transparent window member 6 fixed to the end part on the mounting part 1a side of the optical fiber-fixing member 4, and a cover 7. A plurality of protrusions touching the tubular part 4b of the optical fiber fixing member 4 are formed in the axial direction on the inner wall of the through hole 2a which is covered with the metallization layer 5. According to the structure, brazing stress is scattered and cracks are prevented and since a large number of brazing material sumps are foamed, the optical fiber fixing member 4 can be jointed accurately and rigidly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor element housing package for housing an optical semiconductor element.

[0002]

2. Description of the Related Art Conventionally, an optical semiconductor element housing package for housing an optical semiconductor element such as a laser diode for converting an electric signal used for communication into an optical signal and a photodiode for converting an optical signal into an electric signal is known. As shown in the cross-sectional view of FIG. 3, the optical semiconductor device S is made of an electrical insulating material such as an aluminum oxide sintered body or a metal such as a copper-tungsten alloy, and is provided at a substantially central portion of the upper surface thereof. Placement section
A base 21 having a base 21a, a metallized wiring layer 23 attached to the upper surface of the base 21 so as to surround the mounting portion 21a and extending from the inside to the outside, and a through hole 22a penetrating the inside and outside of the side wall, and a through hole 22a. A ceramic frame 22 having a metallized metal layer 24 attached to the side surface around the through hole 22a, and a flange 25a inserted into the through hole 22a of the ceramic frame 22 and provided at one end thereof are provided with the ceramic frame 22. A substantially cylindrical optical fiber fixing member 25 joined to the metallized metal layer 24 via a brazing material such as silver brazing, and a light transmitting window member attached to the other end of the optical fiber fixing member 25 26, and a lid 27. The optical semiconductor element S is bonded and fixed to the mounting portion 21a of the base 21, and each electrode of the optical semiconductor element S is connected to the metallized wiring layer 23 via a bonding wire W.
And then a lid 27 is joined to the upper surface of the ceramic frame 22 to form the base 21, the ceramic frame 22 and the lid.
An optical semiconductor device as a product is obtained by housing the optical semiconductor element S in an airtight manner inside the container including the optical fiber 27 and inserting the optical fiber F inside the optical fiber fixing member 25.

In such a package for housing an optical semiconductor element, the ceramic frame 22 is usually manufactured by a ceramic green sheet laminating method. Specifically, for example, as shown in an exploded perspective view in FIG. By subjecting the ceramic green sheet of (3) to a conventionally known punching method, three frame-shaped ceramic green sheets 31, 32, and 33 serving as a lower layer, an intermediate layer, and an upper layer are obtained. A notch 32a protruding from the inner periphery to the outer periphery is provided on one end side, and then the metallized wiring layer 23 extends from the inside to the outside surface of the ceramic frame 22 on the upper surface of the frame-shaped ceramic green sheet 32 serving as the intermediate layer. The metal paste to be the part is printed and applied in a predetermined pattern by using a conventionally known screen printing method, and the ceramic grid is coated. Nshito 31, 32, 33 laminated to ceramic green sheet laminate and the pear, then cut one end side of the ceramic green sheet laminate notch 32a
, So that through holes are exposed on the side surfaces of the ceramic green sheet laminate, and the metallized wiring layers 23 are formed on the side surfaces of the ceramic green sheet laminate.
Side of the ceramic frame 22 and metallized metal layer
The metal paste to be 24 is printed and applied in a predetermined pattern using a conventionally known screen printing method, and finally, the ceramic green sheet laminate is fired at a high temperature, as shown in an external perspective view in FIG. It is manufactured to have a metallized wiring layer 23 extending from the inside to the outside surface, a through hole 22a penetrating the inside and outside of the side wall, and a metallized metal layer 24 attached to the side surface around the through hole 22a.

[0004]

However, according to the conventional package for housing an optical semiconductor element, the through-hole 22a formed in the side wall of the ceramic frame 22 has one of the ceramic green sheets serving as the ceramic frame 22. Since the sheet is formed by punching out a notch of a predetermined width by punching, the shape becomes a substantially rectangular rectangular hole, and therefore, the optical fiber is fixed to the metallized metal layer 24 of the ceramic frame 22. When the brazing member 25 is joined via the brazing material, the brazing stress concentrates on the four corners of the through hole 22a, which is a substantially rectangular rectangular hole, and the stress causes the ceramic frame 22 to crack from the four corners. However, there is a drawback that the airtight reliability of the container is low because of the tendency to generate air bubbles.

It is conceivable to form a circular through hole in the side wall of the ceramic frame or the side wall of the green sheet laminate to be the ceramic frame by drilling or the like. Is difficult to drill because the hardness of the ceramic frame is extremely high, and when drilling the ceramic green sheet laminate to be the ceramic frame, the ceramic laminate is soft because the ceramic laminate is soft. The body is easily deformed, and a large amount of shavings generated at the time of drilling adhere to the ceramic green sheet laminate, and it is difficult to obtain a ceramic frame having an accurate shape and no deposits.

Further, when the through hole formed in the side wall of the ceramic frame is circular, if the optical fiber fixing member is to be accurately inserted and fixed in the through hole, the diameter of the through hole is inserted through the hole. It is necessary to make the gap between the inner wall of the through hole and the outer periphery of the optical fiber fixing member extremely small, and in this case, the metallized metal layer and the optical fiber fixing Since only a very small amount of brazing material is formed between the member and the member, the optical fiber fixing member cannot be firmly joined to the ceramic frame.

[0007]

According to a first aspect of the present invention, there is provided a package for storing an optical semiconductor device, wherein the substrate has a mounting portion for an optical semiconductor element in the center of the upper surface, and the mounting portion is surrounded by the outer peripheral portion of the upper surface of the substrate. A ceramic frame having a through hole formed in the side wall and a metallized metal layer attached to a side wall around the through hole, and a substantially cylindrical tube inserted through the through hole. An optical fiber fixing member having a flange attached to the metallized metal layer via a brazing material, and an optical fiber fixing member attached to an end of the optical fiber fixing member on the mounting section side. An optical semiconductor element housing package comprising a light-transmitting window member and a lid attached to an upper surface of the ceramic frame, wherein the through-hole has a cylindrical portion of the optical fiber fixing member on an inner wall. A plurality of contacting protrusions are formed in the axial direction It is and and the metallized metal layer is characterized in that it is deposited over the inner wall of the through hole from the side wall near the through hole.

According to the optical semiconductor element housing package of the present invention, the through hole formed in the ceramic frame has a plurality of projections formed in the inner wall thereof in contact with the cylindrical portion of the optical fiber fixing member in the axial direction. Since the metallized metal layer is applied from the side wall around the through-hole to the inner wall of the through-hole, the number of corners at the opening where the flange of the optical fiber fixing member is brazed is reduced. Many things,
As a result, the brazing stress at the time of joining the optical fiber fixing member to the metallized metal layer of the ceramic frame via the brazing material is dispersed at the many corners and becomes small.

Further, according to the package for housing an optical semiconductor element of the present invention, the through hole formed in the ceramic frame has a plurality of projections on its inner wall which are in contact with the cylindrical portion of the optical fiber fixing member in the axial direction. Since the through hole is formed, the size of the through hole is set to a size in contact with the outer periphery of the optical fiber fixing member inserted therethrough. Even if the positioning can be performed well, a large gap is formed between the optical fiber fixing member and the inner wall of the through hole between the projections in the axial direction from the opening of the through hole to the inner wall. Since many brazing material pools are formed between the metallized metal layer applied from the side wall of the through hole to the inner wall of the through hole and the optical fiber fixing member, the optical fiber fixing member is formed of a ceramic frame. It can be accurately and firmly bonded.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view showing an example of an embodiment of an optical semiconductor element housing package according to the present invention.
Is a base, 2 is a ceramic frame, and 7 is a lid. Mainly, the base 1, the ceramic frame 2, and the lid 7 constitute a container for housing the optical semiconductor element S inside.

The base 1 functions as a support member for supporting the optical semiconductor element S, and has a mounting portion 1a for mounting the optical semiconductor element S at substantially the center of the upper surface thereof. The optical semiconductor element S is bonded and fixed to the mounting portion 1a.

The base 1 is made of, for example, a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, a glass ceramic sintered body, or a copper / copper-based sintered body. An organic binder suitable for a raw material powder such as an aluminum oxide powder, a silicon oxide powder, a magnesium oxide powder, and a calcium oxide powder when made of a metal such as a tungsten alloy, an iron-nickel-cobalt alloy, and, for example, a sintered body of aluminum oxide. A solvent is added and mixed to form a slurry, and this is formed into a sheet by employing a conventionally known doctor blade method to obtain a ceramic green sheet, which is cut into an appropriate size and fired at a high temperature. Produced by

On the outer peripheral portion of the upper surface of the base 1, a mounting portion 1a is provided.
Is surrounded by a ceramic frame 2, and a space for accommodating the optical semiconductor element S is formed inside the ceramic frame 2.

The ceramic frame 2 is made of a ceramic such as a sintered body of aluminum oxide, a sintered body of aluminum nitride, a sintered body of mullite, a sintered body of silicon carbide, and a sintered body of glass ceramic. In the case of an aluminum sintered body, a raw material powder such as an aluminum oxide powder, a silicon oxide powder, a magnesium oxide powder, and a calcium oxide powder is mixed with a suitable organic binder and a solvent to form a slurry, which is conventionally known. A plurality of ceramic green sheets are obtained by forming into a sheet shape by employing a doctor blade method, and then each of the plurality of ceramic green sheets is formed into a frame shape and laminated by employing a conventionally known punching method. To form a green sheet laminate, which is manufactured by firing at a high temperature.

If the ceramic frame 2 is made of the same ceramic material as the substrate 1, a ceramic green sheet to be the ceramic frame 2 is laminated on the ceramic green sheet to be the substrate 1. This is fired together with the ceramic green sheet to be the base 1, and is attached to the base 1 so as to surround the mounting portion 1 a on the outer periphery of the upper surface of the base 1.

A plurality of metallized wiring layers 3 are formed on the ceramic frame 2 so as to extend from the inner side to the outer side of the ceramic frame 2. The electrodes of the optical semiconductor element S are electrically connected via bonding wires W, and external lead terminals (not shown) are provided on the outer surface of the ceramic frame 2 of the metallized wiring layer 3 via a brazing material such as silver brazing. Attached.

The metallized wiring layer 3 is made of a sintered metal powder such as tungsten, molybdenum, copper, silver or the like. A metal paste obtained by adding an appropriate organic binder and solvent to a metal powder such as tungsten is mixed with a ceramic frame. The ceramic green sheet and the green sheet laminate to be the body 2 are printed and applied in a predetermined pattern by using a conventionally known screen printing method, and are fired together with the green sheet laminate to form the inside of the ceramic frame 2. From the outer surface to the outer surface.

The ceramic frame 2 has a through hole 2a formed in the side wall thereof so as to penetrate the ceramic frame 2 in and out. The through hole 2a has a substantially cylindrical tubular portion 4b and a flange 4a. The optical fiber fixing member 4 for fixing the optical fiber, which is provided with the optical fiber, is inserted therethrough.

A through hole 2a formed in the ceramic frame 2
Has a polygonal shape in which square holes having different widths are stacked so that the opening shape becomes narrower in a stepwise manner from the center of the opening toward the upper and lower ends, thereby forming the inner wall of the through hole 2a. A plurality of projections which are in contact with the cylindrical portion 4b of the optical fiber fixing member 4 are formed in the axial direction.

As shown in an exploded perspective view in FIG. 2, for example, as shown in an exploded perspective view of FIG. 2, seven ceramic green sheets 11 to 17 which are punched into a frame and become a ceramic frame 2 are formed.
And notches 12a to 16a serving as through holes 2a are formed at one end sides of the ceramic green sheets 12 to 16 to be intermediate layers by punching with different widths.
17 are laminated to form a green sheet laminate, and one end of the green sheet laminate is cut to expose a through hole on the side surface, thereby forming a cylindrical portion 4b of the optical fiber fixing member 4 on the inner wall thereof. Are formed in the axial direction. In this case, since the through-hole 2a of the ceramic frame 2 is formed by punching out a cutout in a part of the frame-shaped ceramic green sheet to be the ceramic frame 2, it is relatively easily formed. .

A through hole 2a formed in the ceramic frame 2
The opening shape is a polygonal shape in which square holes with different widths are stacked so that the width decreases stepwise from the center of the opening toward the upper and lower ends. Since it is formed in the axial direction, the number of corners in the opening is larger than that of a simple square through-hole, so that the side of the ceramic frame 2 around the through-hole 2a and the When joining the optical fiber fixing member 4 to the metallized metal layer 5 attached to the inner wall of the through hole 2a near the side face via a brazing material, the brazing stress is dispersed to these many corners and small. As a result, it is possible to effectively prevent a crack from being generated around the through hole 2a of the ceramic frame 2 due to the brazing stress.

Further, the through-holes 2a formed in the ceramic frame 2 are square holes of different widths so that the opening shape is stepwise narrower from the center of the opening toward the upper and lower ends. Are stacked, and a plurality of protrusions that are in contact with the cylindrical portion 4b of the optical fiber fixing member 4 are formed on the inner wall in the axial direction, so that the through hole 2a is formed.
The size of the optical fiber fixing member 4 inserted therethrough
Even if the optical fiber fixing member 4 can be accurately positioned in the through hole 2a so as to be in contact with the outer circumference of the through hole 2a, the optical fiber fixing member 4 is inserted into the through hole 2a and the periphery of the through hole 2a as described later. Ceramic frame 2
When the optical fiber fixing member 4 is joined to the metallized metal layer 5 applied from the side surface to the inner wall of the through hole 2a via a brazing material, the corners of the through hole 2a penetrate the optical fiber fixing member 4 with the optical fiber fixing member 4. A large gap is formed between the inner wall of the hole 2a and a large pool of brazing material between the metallized metal layer 5 and the optical fiber fixing member 4 attached to a number of corners on the inner wall of the through hole 2a. As a result, the optical fiber fixing member 4 can be accurately and firmly joined in the through hole 2a of the ceramic frame 2.

The metallized metal layer 5 formed from the side surface around the through hole 2a of the ceramic frame 2 to the inner wall of the through hole 2a is used to braze an optical fiber fixing member 4 to be described later to the ceramic frame 2. Acting as a base metal for the optical fiber fixing member 4 on the metallized metal layer 5.
The optical fiber fixing member 4 is joined to the ceramic frame 2 by brazing through a brazing material such as silver brazing.

The metallized metal layer 5 is made of a sintered body of a metal powder such as tungsten, molybdenum, copper, silver or the like. A metal paste obtained by adding a suitable organic binder and solvent to a metal powder such as tungsten is mixed with a ceramic frame. A predetermined pattern printing is applied to the side surface of the ceramic green sheet laminate to be the body 2 by using a conventionally well-known screen printing method, and at the same time, a part of the metal paste is dripped into the inner wall of the through hole 2a. By firing together with the laminated body, the ceramic frame 2 is formed so as to adhere from the side surface around the through hole 2a to the inner wall of the through hole 2a.

The metallized metal layer 5 applied to the inner wall of the through hole 2a has a width of 0.1 mm from the side of the ceramic frame 2.
If it is less than mm, it tends to be difficult to form a large amount of brazing material pool between the metallized metal layer 5 and the optical fiber fixing member 4. Therefore, it is preferable that the metallized metal layer 5 applied to the inner wall of the through hole 2a of the ceramic frame 2 has a width from the side surface of the ceramic frame 2 less than the thickness of the ceramic frame 2 and 0.1 mm or more.

In the through hole 2a of the ceramic frame 2, an optical fiber fixing member having a flange 4a attached to one end of a substantially cylindrical tubular portion 4b on the side located outside the ceramic frame 2 is provided. The optical fiber fixing member 4 is joined to the metallized metal layer 5 of the ceramic frame 2 via a brazing material such as silver brazing.

The optical fiber fixing member 4 is an optical fiber F
, And an optical fiber F is inserted and fixed therein.

The flange 4a attached to the optical fiber fixing member 4 acts as a joining member for joining the optical fiber fixing member 4 to the ceramic frame 2, and the ceramic frame of the optical fiber fixing member 4 For joining to the body 2, a method of brazing the metallized metal layer 5 adhered to the ceramic frame 2 and the flange 4a via a brazing material such as silver brazing is adopted.

At this time, since the brazing stress is dispersed to many corners of the through hole 2a of the ceramic frame 2, cracks and cracks are generated in the ceramic frame 2 due to the brazing stress. There is no.

At this time, the metallized metal layer 5 adhered to a number of corners on the inner wall of the through hole 2a of the ceramic frame 2 is formed.
Many brazing material pools are formed between the
As a result, the optical fiber fixing member 4 is connected to the ceramic frame 2.
Can be bonded very firmly to

Further, a translucent window member 6 made of sapphire, glass, or the like is attached to the inner end side of the optical fiber fixing member 4, that is, the end on the mounting portion 1 a side of the base 1.

The translucent window member 6 closes an inner space of the cylindrical portion 4b of the optical fiber fixing member 4, and hermetically seals a container constituted by the base 1, the ceramic frame 2 and the lid 7. While transmitting and receiving light between the optical semiconductor element S and the optical fiber F housed in the container through the translucent window member 6.

The translucent window member 6 is attached to the optical fiber fixing member 4 by being glassed or brazed to the inner end side of the optical fiber fixing member 4.

Thus, according to the package for housing an optical semiconductor device of the present invention, the optical semiconductor device S
And the electrodes of the optical semiconductor element S are electrically connected to the metallized wiring layer 3 of the ceramic frame 2 via bonding wires W, and then the lid 7 is joined to the upper surface of the ceramic frame 2. Then, the optical semiconductor element S is accommodated in a container including the base 1, the ceramic frame 2, and the lid 7,
Finally, the optical fiber F is inserted into and fixed to the optical fiber fixing member 4 attached to the ceramic frame 2 to form an optical semiconductor device as a final product, and the optical semiconductor device S and the optical fiber F pass through. By transmitting and receiving an optical signal through the optical window member 6, it is used for high-speed optical communication or the like.

[0036]

According to the package for housing an optical semiconductor element of the present invention, the through hole formed in the ceramic frame has a plurality of projections on the inner wall thereof in contact with the cylindrical portion of the optical fiber fixing member in the axial direction. And the metallized metal layer is applied from the side wall around the through hole to the inner wall of the through hole, so that the corner of the corner portion is formed at the opening where the flange of the optical fiber fixing member is brazed. As a result, the brazing stress at the time of joining the optical fiber fixing member to the metallized metal layer of the ceramic frame via the brazing material is dispersed to a large number of the corners, and the brazing stress becomes small. It is possible to effectively prevent the occurrence of cracks in the ceramic frame due to the stress applied.

Further, according to the package for housing an optical semiconductor element of the present invention, the through hole formed in the ceramic frame has a plurality of projections on its inner wall which are in contact with the cylindrical portion of the optical fiber fixing member in the axial direction. Since the through hole is formed, the size of the through hole is set to a size in contact with the outer periphery of the optical fiber fixing member inserted therethrough. Even if the positioning can be performed well, a large gap is formed between the optical fiber fixing member and the inner wall of the through hole between the projections in the axial direction from the opening of the through hole to the inner wall. Since many brazing material pools are formed between the metallized metal layer applied from the side wall of the through hole to the inner wall of the through hole and the optical fiber fixing member, the optical fiber fixing member is formed of a ceramic frame. It can be accurately and firmly bonded.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of an embodiment of an optical semiconductor element housing package of the present invention.

FIG. 2 is an exploded perspective view for explaining a method of forming a through hole of a ceramic frame of the package for housing an optical semiconductor element shown in FIG.

FIG. 3 is a sectional view of a conventional package for housing an optical semiconductor element.

FIG. 4 is an exploded perspective view for explaining a method of manufacturing a ceramic frame of a conventional package for storing an optical semiconductor element.

FIG. 5 is an external perspective view showing a ceramic frame of a conventional package for housing an optical semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 1a ... Placement part 2 ... Ceramic frame 2a ... Through-hole 3 ... Metallized wiring layer 4 ... Optical fiber fixing member 4a ... Flange 4b ··· cylindrical part 5 ··· metallized metal layer 6 ··· translucent window member 7 ··· lid S · · · optical semiconductor element F · · · optical fiber

Claims (1)

[Claims] 1. A base having a mounting portion for an optical semiconductor element in a central portion of an upper surface, and a base having a through hole formed in an outer peripheral portion of the upper surface of the base so as to surround the mounting portion. And a substantially cylindrical tubular portion inserted into the through-hole and a ceramic frame having a metallized metal layer attached to a side wall around the through-hole and joined to the metallized metal layer via a brazing material. An optical fiber fixing member provided with a flange to be attached, a translucent window member attached to an end of the optical fiber fixing member on the placement section side, and an upper surface of the ceramic frame. An optical semiconductor element housing package comprising a cover to be attached, wherein the through-hole has a plurality of projections formed in an inner wall thereof in contact with a cylindrical portion of the optical fiber fixing member in an axial direction, and The metallized metal layer penetrates from the side wall around the through hole. An optical semiconductor element storage package, which is attached to an inner wall of a hole.