JP3764599B2 - Manufacturing method of optical semiconductor element storage package - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical semiconductor element accommodation package for accommodating an optical semiconductor element.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an optical semiconductor element housing package for accommodating an optical semiconductor element is generally made of a ceramic material such as an aluminum oxide sintered body, and has a base having a recess for accommodating the optical semiconductor element on the upper surface, and the base. And an iron-nickel alloy (iron: 50% by weight, nickel: having a space in which a light signal is transmitted to the inside through a through hole formed in the side portion of the substrate and brazed to the outer surface around the through hole of the base. A cylindrical fixing member made of a metal material such as 50 wt%, a translucent member for closing the inside of the cylindrical fixing member attached to the inside of the cylindrical fixing member via glass, A plurality of wiring conductors made of tungsten, molybdenum, manganese, etc., deposited and led from the inside to the outer surface of the recess, and to which the electrodes of the optical semiconductor element are connected through electrical connection means such as bonding wires And a lid that is attached to the upper surface of the base and closes the recess, and the optical semiconductor element is bonded and fixed in the recess of the base via an adhesive such as glass, resin, or brazing material. At the same time, each electrode of the optical semiconductor element is electrically connected to the wiring conductor layer through an electrical connection means such as a bonding wire, and then the lid is formed of glass, resin, brazing material or the like on the upper surface of the base. The product is formed by bonding through a sealing material, and the optical semiconductor element is hermetically accommodated inside a container composed of a base and a lid, and an optical fiber member is welded and connected to a cylindrical fixing member using a laser beam such as YAG. As an optical semiconductor device.
[0003]
Such an optical semiconductor device causes a predetermined optical excitation to occur in an optical semiconductor element based on a drive signal supplied from an external electric circuit, and transmits and receives the excited light to an optical fiber member through a translucent member. It is used for high-speed communication etc. by transmitting the inside.
[0004]
Further, in the above-described optical semiconductor element housing package, the cylindrical fixing member is attached to the base by brazing by the following method. That is,
(1) First, a nickel plating layer and a gold plating layer are sequentially deposited on the surface of the cylindrical fixing member in order to ensure and securely braze the substrate.
[0005]
The nickel plating layer is a base member for strengthening the adhesion of the gold plating layer to the cylindrical fixing member. By adopting an electrolytic plating method or an electroless plating method, the nickel plating layer is formed on the outer surface of the cylindrical fixing member. Deposited to a thickness of 0.5-5 μm.
[0006]
The gold plating layer has an effect of improving the wettability of the brazing material with respect to the cylindrical fixing member. By adopting an electrolytic plating method or an electroless plating method, the gold plating layer has a thickness of about 1 to 3 μm on the nickel plating layer. Worn.
[0007]
(2) Next, a translucent member is attached to the inside of the cylindrical fixing member via glass to close the inside of the cylindrical fixing member.
[0008]
The translucent member is attached to the cylindrical fixing member. The translucent member has a melting point lower than that of the translucent member, for example, a low melting point solder glass is applied and the applied low melting point solder is applied. The translucent member is placed on the glass and then heated to a temperature of about 450 ° C. in the atmosphere to melt the low melting point glass.
[0009]
(3) Finally, a cylindrical fixing member is brazed and attached to the outer surface around the through hole of the substrate via a low melting point brazing material made of gold-tin alloy or the like, thereby accommodating an optical semiconductor element as a product. The package for is completed.
[0010]
The cylindrical fixing member is brazed to the base body with a cylindrical fixing member on the outer surface around the through hole of the base body and a gold-tin alloy (gold: 80% by weight, tin: 20% by weight) or the like. The melting point brazing material is placed, and then heated to a temperature of about 300 ° C. to melt the low melting point brazing material.
[0011]
[Problems to be solved by the invention]
However, in this conventional method for manufacturing a package for housing an optical semiconductor element, when the translucent member is attached to the inside of the cylindrical fixing member through glass, the cylindrical fixing member is heated by the heat and atmosphere of the glass. A part of the nickel plating layer deposited on the outer surface diffuses in the gold plating layer and is exposed to the gold plating layer surface, which is oxidized and a large amount of nickel oxide is formed on the gold plating layer surface. As a result, since the nickel oxide has poor wettability with the brazing material, the bonding strength of the brazing material to the cylindrical fixing member is greatly reduced, and the cylindrical fixing member cannot be firmly brazed to the base. Had the disadvantages.
[0012]
Therefore, in order to eliminate the above disadvantages, a light-transmitting 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 applied to the surface of the cylindrical fixing member. Conceivable.
[0013]
However, the glass for attaching the translucent member to the inside of the cylindrical fixing member is a low melting point solder glass, and the low melting point solder glass is inferior in chemical resistance. After attaching the member through the glass, if the nickel plating layer and the gold plating layer are deposited 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 cylindrical. The disadvantage of coming off the fixing member is induced.
[0014]
The present invention has been devised in view of the above-described drawbacks, and its object is to manufacture a package for housing an optical semiconductor element in which a cylindrical fixing member is firmly brazed and attached to a base, and the reliability is extremely high. Is to provide.
[0015]
[Means for Solving the Problems]
The present invention includes a base having a recess for accommodating an optical semiconductor element on an upper surface, a through hole formed in a side portion of the base, an outer surface around the through hole of the base, and an optical fiber at one end A cylindrical metal fixing member to which the member is connected, a translucent member attached to the inside of the cylindrical metal fixing member and closing the inside of the metal fixing member, and attached to the upper surface of the base And an optical semiconductor element housing package comprising a lid for closing the recess, wherein the cylindrical metal fixing member is formed on the outer surface around the through-hole of the base body by the following steps (a) to (d). It is characterized by being brazed.
[0016]
(A) a step of sequentially depositing a nickel plating layer and a gold plating layer on the surface of the metal fixing member; (b) applying a glass having a melting point lower than that of the translucent member to the inside of the metal fixing member; (C) the step of attaching the translucent member to the inside of the metal fixing member through the glass by placing the translucent member on the heat treatment, and (c) the metal fixing member in a reducing atmosphere. (D) The other end of the metal fixing member is inserted into the through hole of the base, and the flange of the metal fixing member is brazed to the outer surface around the through hole of the base via a brazing material. Process.
[0017]
According to the method for manufacturing a package for housing an optical semiconductor element of the present invention, after attaching a translucent member to a metal fixing member via glass, gold plating is performed to heat-treat the metal fixing member in a reducing atmosphere. Even if a large amount of nickel oxide having poor wettability and brazing material is formed on the surface of the layer by diffusion and oxidation of the underlying nickel plating layer, the nickel oxide is completely removed by reduction. As a result, the bonding strength of the brazing material to the metallic fixing member in the form of a metal is greatly improved, and the cylindrical metallic fixing member can be brazed and attached to the base very firmly.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in detail with reference to the accompanying drawings.
1 to 4 show an embodiment of a package for housing an optical semiconductor element manufactured by the manufacturing method of the present invention, where 1 is a base and 2 is a lid. The base body 1 and the lid body 2 constitute a container for housing the optical semiconductor element 3 therein.
[0019]
The base 1 is provided with a recess 1a that forms a space for accommodating the optical semiconductor element 3 on the upper surface thereof, and the optical semiconductor element 3 is mounted and fixed on the bottom surface of the recess 1a.
[0020]
The substrate 1 is made of ceramics such as an aluminum oxide sintered body, for example, and an appropriate organic binder, solvent, etc. are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, etc. The slurry is made into a ceramic green sheet (ceramic green sheet) by adopting a doctor blade method or a calender roll method, and then, the ceramic green sheet is appropriately punched and laminated. And is fired at a temperature of about 1500 ° C.
[0021]
The substrate 1 has a plurality of wiring layers 4 deposited from the inner surface of the recess 1 a to the outer surface of the substrate 1, and each region of the optical semiconductor element 3 is exposed in the recess 1 a of the wiring layer 4. Electrodes are electrically connected via bonding wires 5, and external lead terminals 6 connected to external electric circuits are brazed via a brazing material such as silver brazing in a region formed on the outer surface of the substrate 1. It is attached.
[0022]
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 refractory metal powder such as tungsten, molybdenum, or manganese.
[0023]
For example, the wiring layer 4 is made of a conventionally known screen in advance on a ceramic green sheet serving as the substrate 1 by adding and mixing a suitable organic binder, solvent, etc. to a refractory metal powder such as tungsten, molybdenum or manganese. By printing and applying a predetermined pattern by a printing method, the substrate 1 is deposited from the inside of the recess 1a to the outer surface of the substrate 1.
[0024]
The wiring layer 4 is formed by depositing 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 plating. 4 can be effectively prevented, and the brazing of the external lead terminal 6 to the wiring layer 4 can be strengthened. Therefore, the wiring layer 4 is preferably coated with a metal having a thickness of 1 μm to 20 μm, which has excellent corrosion resistance, such as nickel and gold, and excellent wettability with the brazing material, on the exposed surface.
[0025]
Furthermore, external lead terminals 6 are brazed and attached to the wiring layer 4 via a brazing material such as silver solder, and the external lead terminals 6 connect the electrodes of the optical semiconductor element 3 accommodated in the container to external electrical terminals. The optical semiconductor element 3 which is electrically connected to the circuit and is accommodated in the container by connecting the external lead terminal 6 to the external electric circuit is connected to the external electric circuit via the wiring layer 4 and the external lead terminal 6. Will be connected.
[0026]
The external lead terminal 6 is made of a metal material such as iron-nickel-cobalt alloy or iron-nickel alloy. For example, an ingot made of a metal material such as iron-nickel-cobalt alloy is rolled or punched. Then, it is formed into a predetermined shape by applying a conventionally known metal processing method.
[0027]
Further, the external lead terminal 6 is formed by depositing a metal having excellent corrosion resistance such as nickel and gold on the exposed surface and excellent wettability with a brazing material to a thickness of 1 μm to 20 μm by plating. The oxidation corrosion of the lead terminal 6 can be effectively prevented, and when the external lead terminal 6 is connected to the external electric circuit, the connection can be surely and strengthened. Therefore, it is preferable that a metal having excellent corrosion resistance such as nickel and gold and excellent wettability with the brazing material is deposited on the exposed surface of the external lead terminal 6 to a thickness of 1 μm to 20 μm.
[0028]
The base body 1 to which the external lead terminal 6 is attached is also formed with a through hole 1b on its side, and a cylindrical metal fixing member 8 is inserted and fixed in the through hole 1b. A translucent member 9 is attached to a part of the inside of 8.
[0029]
The through hole 1b formed in the side portion of the base body 1 is formed, for example, by forming a hole in a ceramic green sheet to be the base body 1 in advance by a punching method or in the side portion of the base body 1. By processing, it is formed in a predetermined shape on the side portion of the substrate 1.
[0030]
A cylindrical metal fixing member 8 is attached to the periphery of the through-hole 1b on the outer surface of the base 1, and the metal fixing member 8 is a base for fixing the optical fiber member 11 to the base 1. It functions as a fixing member 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 iron-nickel-cobalt alloy or iron-nickel alloy.
[0031]
The metal fixing member 8 is formed, for example, by forming an ingot (lumb) such as an iron-nickel-cobalt alloy into a cylindrical shape by pressing.
[0032]
Further, the metal fixing member 8 is attached to the outer surface of the base 1 by previously attaching a metal layer made of tungsten, molybdenum, or the like around the through hole 1b on the outer surface of the base 1, and then attaching the metal layer to the metal layer. This is performed by brazing a flange provided on the cylindrical metal fixing member 8.
[0033]
Further, the cylindrical metal fixing member 8 has a translucent member 9 attached to a part of the inside thereof, and the translucent member 9 closes the inner side of the metal fixing member 8 and An optical fiber member 11 that holds the hermetic seal of the container formed of the lid 2 and is connected to the metallic fixing member 8 as it is by the excited light of the optical semiconductor element 3 that transmits the internal space of the metallic fixing member 8. It acts to transmit to.
[0034]
The translucent member 9 is made of, for example, lead-based silicon oxide, lead oxide containing lead oxide as a main component and boric acid-based amorphous glass containing siliceous sand as a main component. Since glass has no crystal axis, when the light excited by the optical semiconductor element 3 passes through the light transmissive member 9 and is transferred to the optical fiber member 11, the light excited by the optical semiconductor element 3 is transmitted by the light transmissive member 9. Birefringence does not occur and the light is transmitted to the optical fiber member 11 as it is. As a result, transmission / reception of the light excited by the optical semiconductor element 3 to the optical fiber member 11 becomes highly efficient and the transmission efficiency of the optical signal is high. Can be
[0035]
The cylindrical metal fixing member 8 has a flange attached to an optical fiber member 11 at one end on the outer side thereof and is welded using a laser beam such as YAG, thereby transmitting an optical signal to the optical semiconductor element 3. Therefore, the optical fiber member 11 is fixed to the base 1.
[0036]
Further, a lid body 2 made of a metal material such as iron-nickel-cobalt alloy or iron-nickel alloy is joined to the upper surface of the base body 1, whereby the inside of the container composed of the base body 1 and the lid body 2 is joined. The optical semiconductor element 3 is hermetically sealed.
[0037]
The lid 2 is formed in a predetermined shape by applying a conventionally known metal processing method such as a rolling method or a punching method to an ingot (lumb) such as an iron-nickel-cobalt alloy.
[0038]
Thus, according to the optical semiconductor element housing package of the present invention, the optical semiconductor element 3 is placed and fixed in the recess 1a of the base 1, and each electrode of the optical semiconductor element 3 is electrically connected to the wiring layer 4 via the bonding wires 5. Next, the lid body 2 is joined to the upper surface of the base body 1, the optical semiconductor element 3 is accommodated inside the container composed of the base body 1 and the lid body 2, and finally attached to the base body 1. By attaching and connecting the optical fiber member 11 to the metal fixing member 8, an optical semiconductor device as a final product is obtained.
[0039]
Such an optical semiconductor device causes a predetermined optical excitation of the optical semiconductor element 3 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 via the translucent member 9. It is used for high-speed communication or the like by transmitting the inside of the optical fiber of the member 11.
[0040]
Next, attachment of the metal fixing member to the base in the optical semiconductor element housing package will be described with reference to FIGS.
First, as shown in FIG. 5 (a), a nickel plating layer 12 and a gold plating layer 13 are sequentially coated on the surface of a cylindrical metal fixing member 8 in order to ensure and secure brazing to the base 1. Put on.
[0041]
The nickel plating layer 12 is a base member for strengthening the adherence of the gold plating layer 13 to the metal fixing member 8. By adopting an electrolytic plating method or an electroless plating method, the nickel plating layer 12 It is applied to the surface to a thickness of about 0.5-5 μm.
[0042]
When the nickel plating layer 12 is formed by adopting an electrolytic plating method, the metal fixing member 8 is made of, for example, nickel sulfate, nickel chloride, boric acid (NiSO ₄ .6H ₂ O + NiCl ₂ + 6H ₂ O + H ₃ BO). ₃ ) and is applied by applying a plating power having a current density of about 0.1 to ^{2 A} / dm ² to the metal fixing member 8 while being immersed in the nickel plating bath.
[0043]
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 has a thickness of about 1 to 3 μm on the nickel plating layer by employing an electrolytic plating method or an electroless plating method. To be attached.
[0044]
When the gold plating layer 13 is formed by adopting an electrolytic plating method, a metal fixing member 8 having a nickel plating layer 12 deposited on the surface thereof, for example, gold gold consisting of potassium gold cyanide and potassium phosphate is used. It is performed by immersing in a 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.
[0045]
Next, as shown in FIG. 5B, the translucent member 9 is attached to the inside of the metal fixing member 8 through the glass 14 to close the inside of the metal fixing member 8.
[0046]
The translucent member 9 is attached to the metal fixing member 8 by applying a low melting point solder glass 14 having a melting point lower than the melting point of the translucent member 9 to the inside of the metal fixing member 8. The translucent member 9 is placed on the applied low melting point solder glass 14 and then heated to a temperature of about 450 ° C. in the atmosphere to melt the low melting point solder glass 14. In this case, a part of the nickel plating layer 12 deposited on the surface of the metal fixing member 8 by the heat and atmosphere of glass is diffused in the gold plating layer 13 and exposed to the surface of the gold plating layer 13. The nickel exposed on the surface of the gold plating layer 13 is oxidized and becomes nickel oxide, and a large amount is formed on the surface of the gold plating layer 13.
[0047]
Next, the metal fixing member 8 is heat-treated in a reducing atmosphere to reduce and remove nickel oxide formed in a large amount on the surface of the gold plating layer 13.
[0048]
The reducing atmosphere is preferably a hydrogen atmosphere, a nitrogen atmosphere, or a mixed atmosphere of hydrogen and nitrogen, and the temperature of the heat treatment is higher than the melting point of the glass 14 that attaches the translucent member 9 to the metal fixing member 8. A low temperature, for example, a range of 200 to 420 ° C is preferable.
[0049]
Since the metal fixing member 8 has nickel oxide having poor wettability with respect to the brazing material formed on the surface of the gold plating layer 13 removed by heat treatment in a reducing atmosphere, The wettability is extremely good.
[0050]
Finally, the metal fixing member 8 is brazed and attached to a metal layer in which the metal fixing member 8 is preliminarily attached to the periphery of the through hole 1b of the base 1 via a brazing material 15 as shown in FIG. The brazing attachment of the metal fixing member 8 to the end is completed.
[0051]
The metal fixing member 8 is brazed and attached to the base body 1 by placing a gold-tin alloy (gold: 80% by weight, tin: 20% by weight) on the metal layer deposited around the through hole 1b of the base body 1. %) And the like, and then, the low melting point brazing material 15 is heated to a temperature of about 300 ° C. to melt the low melting point brazing material 15. In this case, since the metallic fixing member 8 has nickel oxide having poor wettability with respect to the brazing material formed on the surface of the gold plating layer 13 removed by heat treatment in a reducing atmosphere, The brazing material 15 is joined very firmly, whereby the metal fixing member 8 is brazed and attached to the base 1 very firmly.
[0052]
It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiments, the optical semiconductor element 3 is optical. However, this is also applicable to the case where the light transmitted through the optical fiber member 11 is converted into an electrical signal by the optical semiconductor element 3 and the converted electrical signal is extracted to the outside. It is.
[0053]
In the above-described embodiment, the substrate 1 is formed of a ceramic such as an aluminum oxide sintered body, but it may be formed of a metal material such as an iron-nickel-cobalt alloy.
[0054]
【The invention's effect】
According to the method for manufacturing a package for housing an optical semiconductor element of the present invention, after attaching a translucent member to a metal fixing member via glass, gold plating is performed to heat-treat the metal fixing member in a reducing atmosphere. Even if a large amount of nickel oxide with poor wettability is formed on the surface of the layer by diffusion and oxidation of the underlying nickel plating layer, the nickel oxide must be completely removed by heat treatment in a reducing atmosphere. As a result, the bonding strength of the brazing material to the cylindrical metal fixing member is greatly improved, and the cylindrical metal fixing member can be brazed and attached to the base very firmly.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an optical semiconductor element housing package of the present invention.
2 is a fragmentary cross-sectional view of the optical semiconductor element housing package shown in FIG. 1;
3 is a side view of the optical semiconductor element housing package shown in FIG. 1. FIG.
4 is a plan view of the optical semiconductor element housing package shown in FIG. 1 with a cover removed. FIG.
5 (a) to 5 (c) are cross-sectional views of the main part of each process when the metal fixing member of the optical semiconductor element housing package shown in FIG. 1 is brazed to the base.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base | substrate 1a .. Recessed part 1b .. Through-hole 2 ... Cover body 3 ... Optical semiconductor element 4 ... Wiring layer 8 ... Cylindrical metal fixing member 9 ... Translucent Member 11 ... optical fiber member 12 ... nickel plating layer 13 ... gold plating layer 14 ... glass 15 ... brazing material

Claims (2)

A substrate have a recess for accommodating the optical semiconductor element, the through-hole on the side is formed on the upper surface,
With flange provided is brazed to the outer surface of the through hole near the base at one end and the other end is inserted into the through hole of the base body, a cylindrical metal fiber member is connected A fixing member made of,
Is attached inside the metal securing member, and the translucent member for closing the interior of said metal securing member,
A method of manufacturing a package for housing an optical semiconductor element comprising a lid attached to an upper surface of the base and closing the recess,
Said flange of said metal securing member, following by sequentially performing the (a) step (d), the optical semiconductor element characterized in that it is brazed to the outer surface of the through hole near the base A method for manufacturing a storage package.
(A) inside the metal securing nickel plated layer on the surface of the member and the step of gold plating layer are sequentially deposited (b) the metal securing member is coated with a glass having a melting point lower than that of the light transmitting member, by placing the translucent member to the glass, heat treatment by melting the glass subjected to the step of attaching the inside the translucent member through the glass of the metal securing member ( c) inserting the other end of the heat treatment, step; (d) metal securing member said metal securing member in a reducing atmosphere in the through hole of the base, the flange of the metal fixing member of the base body a step of brazing attached via a brazing material to the outer surface of the periphery of the above through hole. 2. The method for manufacturing an optical semiconductor element housing package according to claim 1, wherein the heat treatment in the step (c) is performed at a temperature lower than the melting point of the glass.

Images