JP2000277758A - Manufacture of package for housing optical semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a manufacturing method for a package to house an optical semiconductor element, in which a cylindrical fixing member is brazed and attached firmly to a base body and whose reliability is made extremely high. SOLUTION: A cylindrical metal fixing member 8, to which an optical fiber member is connected, is brazed and attached to a base body 1 in which an optical semiconductor element 3 is housed. At this time, the metal fixing member 8 is removed, in which a nickel-plated layer 12 and a gold-plated layer 13 are applied sequentially to the surface and to which a trunsmissive member 9 is attached at the inside via a glass 14 is heated and treated in a reduced atmosphere, and nickel oxide which is formed on the surface of the gold-plated layer 13.

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 is generally made of a ceramic material such as an aluminum oxide sintered body and has a concave portion for housing the optical semiconductor element on an upper surface. An iron-nickel alloy (iron: 50) which has a base, a through hole formed in a side portion of the base, and a space which is brazed and attached to an outer surface around the through hole of the base and has a space for transmitting an optical signal therein. (Weight%, nickel: 50% by weight) or the like, and a translucent member for closing the inside of the cylindrical fixing member attached to the inside of the cylindrical fixing member via glass. And tungsten, molybdenum, manganese, etc., which are attached and led from the inside of the concave portion to the outer surface of the base, and the electrodes of the optical semiconductor element are connected via electrical connection means such as bonding wires. Pieces of the wiring conductor layer, is attached to the upper surface of the substrate, are composed of a lid for closing said recess, glass optical semiconductor elements in a recess of the base body resin,
Each electrode of the optical semiconductor element is electrically connected to a wiring conductor layer via an electrical connection means such as a bonding wire while being fixedly adhered through an adhesive such as a brazing material, and thereafter,
A lid is bonded to the upper surface of the base via a sealing material made of glass, resin, brazing material, or the like, and the optical semiconductor element is hermetically accommodated inside a container formed of the base and the lid, and is attached to the cylindrical fixing member. An optical semiconductor device as a product is obtained by welding and connecting the optical fiber member using a laser beam such as YAG.

In such an optical semiconductor device, a predetermined optical excitation is caused in an optical semiconductor element based on a drive signal supplied from an external electric circuit, and the excited light is transmitted to and received from an optical fiber member through a light transmitting member. It is used for high-speed communication and the like by transmitting the light through the optical fiber of the member.

In the above-mentioned package for housing an optical semiconductor element, the cylindrical fixing member is brazed to the base by the following method. That is, (1) First, a nickel plating layer and a gold plating layer are sequentially applied on the surface of the cylindrical fixing member in order to securely and firmly attach to the base by brazing.

The nickel plating layer is a base member for firmly attaching the gold plating layer to the cylindrical fixing member,
By adopting the electrolytic plating method or the electroless plating method, it is attached to the outer surface of the cylindrical fixing member to a thickness of about 0.5 to 5 μm.

The gold plating layer has an effect of improving the wettability of the brazing material to the cylindrical fixing member, and is formed on the nickel plating layer by an electrolytic plating method or an electroless plating method. Deposited in thickness.

(2) Next, a translucent member is attached to the inside of the cylindrical fixing member via glass, and the inside of the cylindrical fixing member is closed.

The light-transmitting member is attached to the cylindrical fixing member by applying a low-melting point solder glass having a melting point lower than the melting point of the light-transmitting member, for example, to the inside of the cylindrical fixing member. This is performed by placing a light-transmissive member on low-melting-point solder glass and then heating it to a temperature of about 450 ° C. in air to melt the low-melting-point glass.

(3) Finally, a cylindrical fixing member is brazed and attached to the outer surface of the substrate around the through hole through a low melting point brazing material made of a gold-tin alloy or the like. The package for housing the semiconductor element is completed.

[0010] The cylindrical fixing member is brazed to the base by mounting the cylindrical fixing member on the outer surface around the through-hole of the base, with a gold-tin alloy (gold: 80% by weight, tin: 20% by weight) or the like. Is placed with a low melting point brazing material consisting of
It is performed by heating to a temperature of ° C. to melt the low melting point brazing material.

[0011]

However, in this conventional method of manufacturing a package for housing an optical semiconductor element, when a light-transmitting member is attached to the inside of a cylindrical fixing member via glass, the glass is attached. Due to heat and atmosphere, part of the nickel plating layer adhered to the outer surface of the cylindrical fixing member diffuses in the gold plating layer and is exposed on the gold plating layer surface, and is oxidized and oxidized on the gold plating layer surface. A large amount of nickel may be formed. As a result, since the nickel oxide has poor wettability with the brazing material, the joining strength of the brazing material to the cylindrical fixing member is significantly reduced, and the cylindrical fixing member is firmly attached to the base. Has the disadvantage that it cannot be brazed and attached.

In order to solve the above-mentioned drawback, a translucent member is attached to the inside of the cylindrical fixing member via glass, and then a nickel plating layer and a gold plating layer are sequentially deposited on the surface of the cylindrical fixing member. It is possible to make it.

However, the glass for attaching the translucent member inside the cylindrical fixing member is a low melting point solder glass, and since the low melting point solder glass is inferior in chemical resistance, the glass is fixed inside the cylindrical fixing member. After attaching the translucent member via the glass, and then applying a nickel plating layer and a gold plating layer on the surface of the cylindrical fixing member, the glass is melted by the chemical of the plating solution, and as a result, the translucent member Is detached from the cylindrical fixing member.

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to provide a highly reliable optical semiconductor device housing package in which a cylindrical fixing member is firmly brazed and attached to a base. It is to provide a manufacturing method of.

[0015]

According to the present invention, there is provided a base having a concave portion for accommodating an optical semiconductor element on an upper surface, a through hole formed in a side portion of the base, and an outer portion around the through hole of the base. A cylindrical metal fixing member brazed to the surface and having one end connected to an optical fiber member; and a translucent member attached to the inside of the cylindrical metal fixing member and closing the inside of the metal fixing member. And a lid attached to the upper surface of the base and closing the recess, wherein the cylindrical metal fixing member is formed of the following (a) to (d).
Is brazed to the outer surface around the through-hole of the substrate by the step of.

(A) a step of sequentially depositing a nickel plating layer and a gold plating layer on the surface of a cylindrical metal fixing member;
(B) attaching a translucent member to the inside of the metal fixing member via glass; (c) heating the metal fixing member in a reducing atmosphere; and (d) metal fixing member. And brazing the outer surface around the through-hole of the base through a brazing material.

According to the method of manufacturing a package for housing an optical semiconductor element of the present invention, after a translucent member is attached to a metal fixing member via glass, the metal fixing member is heated in a reducing atmosphere. Therefore, even if a large amount of nickel oxide having poor wettability with the brazing material is formed on the surface of the gold plating layer by diffusion and oxidation of the underlying nickel plating layer, the nickel oxide is completely removed by reduction,
As a result, the joining strength of the brazing material to the cylindrical metal fixing member is greatly improved, and the cylindrical metal fixing member can be extremely firmly brazed and attached to the base.

[0018]

Next, the present invention will be described in detail with reference to the accompanying drawings. 1 to 4 show an embodiment of an optical semiconductor element housing package manufactured by the manufacturing method of the present invention, wherein 1 is a base, and 2 is a lid. The base 1 and the lid 2 constitute a container for housing the optical semiconductor element 3 therein.

The base 1 is provided on its upper surface with a concave portion 1a forming a space for accommodating the optical semiconductor element 3,
The optical semiconductor element 3 is mounted and fixed on the bottom surface of the concave portion 1a.

The base 1 is made of, for example, ceramics such as an aluminum oxide sintered body, and is mixed with a raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide by adding an appropriate organic binder, a solvent, and the like. The slurry is made into a ceramic green sheet (ceramic green sheet) by employing a doctor blade method or a calender roll method, and then the ceramic green sheet is subjected to an appropriate punching process, and then the slurry is formed. Laminate multiple sheets, about 1500
It is manufactured by firing at a temperature of ° C.

A plurality of wiring layers 4 are formed on the substrate 1 from the inner surface of the concave portion 1a to the outer surface of the substrate 1, and a region of the wiring layer 4 exposed in the concave portion 1a has an optical semiconductor element. 3 are electrically connected to each other through bonding wires 5, and external lead terminals 6 connected to an external electric circuit are made of a brazing material such as silver brazing in a region formed on the outer surface of the base 1. It is attached via brazing.

The wiring layer 4 functions as a conductive path for connecting each electrode of the optical semiconductor element 3 to an external electric circuit, and is formed of a high melting point metal powder such as tungsten, molybdenum, and manganese.

The wiring layer 4 is formed by adding a metal paste obtained by adding a suitable organic binder, a solvent, and the like to a high melting point metal powder such as tungsten, molybdenum, manganese, or the like to a ceramic green sheet serving as the base 1 beforehand. By printing and applying a predetermined pattern by a well-known screen printing method, the coating is formed from the inside of the concave portion 1 a of the base 1 to the outer surface of the base 1.

The wiring layer 4 is preferably provided with a metal having excellent corrosion resistance such as nickel and gold and excellent wettability with a brazing material to a thickness of 1 μm to 20 μm by a plating method on the exposed surface. In addition, the oxidation corrosion of the wiring layer 4 can be effectively prevented, and the brazing of the external lead terminals 6 to the wiring layer 4 can be firmly performed. Therefore, it is preferable that a metal having excellent corrosion resistance, such as nickel and gold, and excellent in wettability with a brazing material is applied to the exposed surface of the wiring layer 4 to a thickness of 1 μm to 20 μm.

Further, an external lead terminal 6 is attached to the wiring layer 4 by brazing via a brazing material such as silver brazing, and the external lead terminal 6 is connected to the optical semiconductor element 3 contained in the container.
The optical semiconductor element 3 accommodated in the container by connecting the external lead terminals 6 to the external electric circuit is electrically connected to the external electric circuit.
And the external lead terminal 6 is connected to an external electric circuit.

The external lead terminal 6 is made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy.
For example, an ingot made of a metal material such as an iron-nickel-cobalt alloy is formed into a predetermined shape by applying a conventionally known metal working method such as a rolling method or a punching method.

The external lead terminal 6 is coated with a metal having excellent corrosion resistance and excellent wettability with a brazing material to a thickness of 1 μm to 20 μm by a plating method on the exposed surface thereof. In addition, when the external lead terminal 6 is connected to an external electric circuit, the connection can be reliably prevented.
It can be made strong. Therefore, the external lead terminal 6 is made of a metal having excellent corrosion resistance such as nickel and gold and excellent wettability with a brazing material of 1 μm to 2 μm on the exposed surface.
Preferably, it is applied to a thickness of 0 μm.

The base 1 on which the external lead terminals 6 are attached
Further, a through hole 1b is formed in a side portion thereof. A cylindrical metal fixing member 8 is inserted and fixed in the through hole 1b, and a translucent member is further provided in a part of the inside of the metal fixing member 8. 9 is attached.

The through-hole 1b formed in the side of the base 1 may be formed, for example, by forming a hole in a ceramic green sheet to be the base 1 in advance by a punching method, or Is formed into a predetermined shape on the side portion of the base 1 by performing a drilling process.

A cylindrical metal fixing member 8 is attached to the outer surface of the base 1 around the through hole 1b, and the metal fixing member 8 fixes the optical fiber member 11 to the base 1. It functions as a base fixing member at the time and transmits light excited by the optical semiconductor element 3 to the optical fiber member 11, and is made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy.

The metal fixing member 8 is, for example,
It is formed by forming an ingot (lump) such as an iron-nickel-cobalt alloy into a tubular shape by press working.

In attaching the metal fixing member 8 to the outer surface of the base 1, a metal layer made of tungsten, molybdenum, or the like is previously applied to the outer surface of the base 1 around the through hole 1b. This is performed by brazing a flange provided on the cylindrical metal fixing member 8 to the metal layer.

Further, a light-transmitting member 9 is attached to a part of the inside of the cylindrical metal fixing member 8, and the light-transmitting member 9 closes the inside of the metal fixing member 8. Light excited by the optical semiconductor element 3 that transmits the internal space of the metal fixing member 8 is attached and connected to the metal fixing member 8 as it is while maintaining the hermetic sealing of the container including the base 1 and the lid 2. It functions to transmit the light to the optical fiber member 11.

The light transmitting member 9 is made of, for example, silicon oxide,
It is made of lead-based and boric acid containing lead oxide as a main component, and borosilicate-based amorphous glass containing silica sand as a main component.
Since the amorphous glass has no crystal axis, the light excited by the optical semiconductor element 3 is transmitted and received by the optical fiber member 11 through the light transmitting member 9. The birefringence does not occur in the member 9 and is transmitted and received to the optical fiber member 11 as it is,
As a result, the transmission and reception of the light excited by the optical semiconductor element 3 to and from the optical fiber member 11 becomes high, and the transmission efficiency of the optical signal can be made high.

The flange fixed to the optical fiber member 11 is welded to the outer end of the cylindrical metal fixing member 8 using a laser beam such as YAG. The optical fiber member 11 for transmitting the light is fixed to the base 1.

Further, on the upper surface of the substrate 1, for example,
A lid 2 made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy is joined, and
The optical semiconductor element 3 is hermetically sealed inside a container formed of the cover 2 and the cover 2.

The lid 2 is formed in a predetermined shape by subjecting an ingot such as an iron-nickel-cobalt alloy to a conventionally known metal working method such as a rolling method or a punching method. .

Thus, according to the package for housing an optical semiconductor element of the present invention, the optical semiconductor element 3 is placed and fixed in the concave portion 1a of the base 1, and each electrode of the optical semiconductor element 3 is connected to the wiring layer 4 via the bonding wire 5. Then, the lid 2 was joined to the upper surface of the base 1, and the optical semiconductor element 3 was accommodated in a container composed of the base 1 and the lid 2, and finally attached to the base 1. By attaching and connecting the optical fiber member 11 to the tubular metal fixing member 8, an optical semiconductor device as a final product is obtained.

The optical semiconductor device causes the optical semiconductor element 3 to perform predetermined light excitation based on a drive signal supplied from an external electric circuit, and transmits and receives the excited light to and from the optical fiber member 11 through the translucent member 9. In addition, by transmitting the light through the optical fiber of the optical fiber member 11, it is used for high-speed communication and the like.

Next, the attachment of the metal fixing member to the base in the package for housing an optical semiconductor element will be described with reference to FIG.
A description will be given based on (a) to (c). First, as shown in FIG. 5A, the base 1 is attached to the surface of the cylindrical metal fixing member 8.
The nickel plating layer 12 and the gold plating layer 13 are successively applied in order to securely and firmly attach to the brazing layer.

The nickel plating layer 12 is a base member for firmly attaching the gold plating layer 13 to the metal fixing member 8. The nickel plating layer 12 is made of metal by adopting an electrolytic plating method or an electroless plating method. About 0.5 to 5μ on the surface of the member 8
m.

[0042] The nickel plating layer 12 if formed by employing the electrolytic plating method which, a metal securing member 8, for example, nickel sulfate, nickel chloride, boric acid _{(NiSO 4 · 6H 2 O +} NiCl 2 + 6H 2 O +
H ₃ BO ₃ ) and a current density of 0.1 to 2 A / dm on the metal fixing member 8.
It is performed by applying about ² electric power for plating.

The gold plating layer 13 has an effect of improving the wettability of the brazing material with respect to the metal fixing member 8, and is formed on the nickel plating layer by an electrolytic plating method or an electroless plating method. Deposited to a thickness of 3 μm.

When the gold plating layer 13 is formed by employing an electrolytic plating method, the metal fixing member 8 having the nickel plating layer 12 adhered to the surface thereof may be made of, for example, gold potassium cyanide and potassium phosphate. The plating is performed by immersing the metal fixing member 8 in a gold plating bath and applying a plating power having a current density of about 0.2 to 1.5 A / dm ² to the metal fixing member 8.

Next, as shown in FIG. 5B, a translucent member 9 is attached to the inside of the metal fixing member 8 via the glass 14 to close the inside of the metal fixing member 8.

Attachment of the light transmitting member 9 to the metal fixing member 8 has a melting point lower than the melting point of the light transmitting member 9 inside the metal fixing member 8, for example, a low melting point solder glass 14.
And the applied low melting point solder glass 14
The translucent member 9 is placed on the upper part, and thereafter, this is
This is performed by heating to a temperature of about 450 ° C. to melt the low melting point solder glass 14. In this case, the nickel plating layer 12 adhered to the surface of the metal fixing member 8 due to the heat and atmosphere of the glass is partially diffused in the gold plating layer 13 to be exposed on the surface of the gold plating layer 13. ,
The nickel exposed on the surface of the gold plating layer 13 is oxidized to nickel oxide and formed in a large amount on the surface of the gold plating layer 13.

Next, the metal fixing member 8 is heat-treated in a reducing atmosphere to reduce and remove a large amount of nickel oxide formed on the surface of the gold plating layer 13.

The reducing atmosphere is preferably a hydrogen atmosphere, a nitrogen atmosphere, or a mixed atmosphere of hydrogen and nitrogen.
The temperature of the heat treatment is preferably lower than the melting point of the glass 14 for attaching the translucent member 9 to the metal fixing member 8, for example, in the range of 200 to 420 ° C.

The metal fixing member 8 has a low wettability with respect to the brazing material formed on the surface of the gold plating layer 13, and is removed by heat treatment in a reducing atmosphere. The wettability to the brazing material is extremely good.

Finally, the metal fixing member 8 is brazed and attached to the metal layer previously attached to the periphery of the through hole 1b of the base 1 through the brazing material 15 as shown in FIG.
As shown in (c), the brazing attachment of the metal fixing member 8 to the base 1 is completed.

The metal fixing member 8 is attached to the base 1 by brazing. A gold-tin alloy (gold: 80% by weight, tin) is interposed between a metal layer provided around the through hole 1b of the base 1. : 20% by weight) and the like, and then placed on the low melting point brazing material 15 and then heated to a temperature of about 300 ° C. to melt the low melting point brazing material 15. In this case, the metal fixing member 8 has a low wettability with respect to the brazing material formed on the surface of the gold plating layer 13 and has been removed by heat treatment in a reducing atmosphere. Very firmly joined to the brazing material 15,
As a result, the metal fixing member 8 is very firmly brazed and attached to the base 1.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention.
Although the case where the optical semiconductor element 3 excites light has been described, the optical semiconductor element 3 converts the light transmitted through the optical fiber member 11 into an electric signal, and extracts the converted electric signal to the outside. It is also applicable to the case where it is done.

In the above-described embodiment, the base 1 is formed of ceramics such as an aluminum oxide sintered body, but may be formed of a metal material such as an iron-nickel-cobalt alloy.

[0054]

According to the method of manufacturing a package for housing an optical semiconductor element of the present invention, after a translucent member is attached to a metal fixing member via glass, the metal fixing member is heated in a reducing atmosphere. Even if a large amount of nickel oxide having poor wettability with the brazing material is formed on the surface of the gold plating layer by diffusion and oxidation of the underlying nickel plating layer due to the treatment, the nickel oxide can be completely treated by heat treatment in a reducing atmosphere. As a result, the joining strength of the brazing material to the cylindrical metal fixing member is greatly improved, and the cylindrical metal fixing member can be extremely firmly brazed and attached to the base. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a package for housing an optical semiconductor element of the present invention.

FIG. 2 is a sectional view of a main part of the package for housing an optical semiconductor element shown in FIG. 1;

FIG. 3 is a side view of the package for housing an optical semiconductor element shown in FIG. 1;

FIG. 4 is a plan view of the package for storing an optical semiconductor element shown in FIG. 1 in a state where a lid is removed.

5 (a) to 5 (c) are cross-sectional views of main parts in each step when a metal fixing member of the package for storing an optical semiconductor element shown in FIG. 1 is brazed and attached to a base.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 1a ... Depression 1b ... Through-hole 2 ... Lid 3 ... Optical semiconductor element 4 ... Wiring layer 8 ... Cylindrical metal fixing member 9 ... Light transmission Functional member 11: Optical fiber member 12: Nickel plating layer 13: Gold plating layer 14: Glass 15: Brazing material

Claims (1)

[Claims] 1. A base having a concave portion for accommodating an optical semiconductor element on an upper surface, a through hole formed in a side portion of the base,
A cylindrical metal fixing member brazed to the outer surface around the through hole of the base, and an optical fiber member connected to one end; and a metal fixing member attached to the inside of the cylindrical metal fixing member. And a lid attached to the upper surface of the base and closing the recess, wherein the cylindrical metal fixing member is formed of the following (a). And (d) brazing the outer surface around the through hole of the base body to the optical semiconductor element housing package. (A) a step of sequentially depositing a nickel plating layer and a gold plating layer on the surface of a cylindrical metal fixing member; and (b) attaching a translucent member to the inside of the metal fixing member via glass. (C) heating the metal fixing member in a reducing atmosphere, and (d) brazing the metal fixing member to the outer surface around the through hole of the base via a brazing material.