JP3635651B2 - Window glass for optical semiconductor and optical semiconductor module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a window glass and an optical semiconductor module used in a package for storing an optical semiconductor .
[0002]
[Prior art]
Conventionally, in the optical semiconductor module, as shown in FIG. 2, a semiconductor laser 10 as an optical semiconductor is fixed to a bottom 3 d called a stem through a spacer 11 and a base 13 in an optical semiconductor package 3, and The structure is connected to the airtightly fixed leads 15 and 16. The window glass 1 for optical semiconductors used in this optical semiconductor module uses a circular plate-like body 1a having an optical film 12 for preventing reflection and wavelength filtering. Conventionally, this window glass is an optical semiconductor. Is fixed to the contact surface 3b of the window hole portion 3a provided at the top of the cylindrical cap 3c of the package 3 using an adhesive 14 made of low-melting glass. The light beam emitted from the semiconductor laser 10 passes through the light transmitting portion 1b of the window glass 1 for optical semiconductors and is emitted toward the outside.
[0003]
[Problems to be solved by the invention]
However, the material of the optical semiconductor package 3 includes a material that deteriorates when the low melting point glass of the adhesive 14 melts and adheres to a temperature of 400 ° C. or higher, and a material that has poor wettability with the low melting point glass. In recent years, optical semiconductor modules for optical communication have been required to have high quality for the light beam used. For this reason, an optical film 12 such as a high-performance filter has been formed on the surface of the window glass 1. There are problems with conventional low melting point glass bonding methods, such as those that deteriorate at high temperatures of 400 ° C. and lose desired optical properties. Therefore, there are cases where the window glass 1 is bonded using an organic adhesive, but the optical semiconductor is contaminated by the point of preventing accumulation of static electricity, the reliability of the hermetic part, and the volatile component from the adhesive. There is a problem in terms of deterioration.
[0004]
The present invention solves the problems of the conventional window glass for optical semiconductors as described above, and the window glass for optical semiconductors that can be reliably and hermetically fixed to the metal surface of the package for optical semiconductors using solder. And an optical semiconductor module .
[0005]
[Means for Solving the Problems]
An optical semiconductor window glass according to the present invention is an optical semiconductor window glass fixed to a window hole portion of an optical semiconductor package. A titanium film, a chromium film, or nickel chrome is formed on the surface of the window glass as a first layer. It is characterized by comprising a metal multilayer film for fixing composed of a film selected from the films, a palladium film as the second layer, and a gold film as the third layer.
[0006]
In addition, an optical semiconductor module according to the present invention includes the above-mentioned window glass for optical semiconductors.
[0007]
According to the window glass for optical semiconductors of the present invention, on the surface of the window glass, a film selected from a titanium film, a chromium film, or a nickel chromium film as the first layer, a palladium film as the second layer, and a third layer Since it has a metal multilayer film for fixing made of gold film, the titanium film, chromium film or nickel chromium film directly formed on the surface of the glass of the metal multilayer film has the property of strongly bonding to glass. In addition, the gold film of the third layer has good wettability with solder and can be hermetically fixed with sufficient adhesion strength to the metal contact surface of the window hole portion of the metal optical semiconductor package. In addition, since a palladium film is interposed as the second layer between the metal films, stress due to film deposition hardly occurs, and film peeling due to stress acting on the film does not occur. Furthermore, since the palladium film acts to prevent mutual diffusion between the solder component and the glass component, the film thickness of the gold film in contact with the solder can be reduced, and the optical semiconductor window glass can be stably fixed over a long period of time. It becomes possible.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The window glass for optical semiconductors of the present invention is a plate-shaped body made of glass that is transparent to light having a wavelength emitted or received by an optical semiconductor, and is made of a metal in a window hole portion of a package that houses the optical semiconductor The contact surface has a metal multilayer film having an annular three-layer structure for hermetically fixing using solder. This metal multilayer film has a first layer selected from a titanium film, a chromium film or a nickel chromium film having excellent adhesion to the glass surface of the plate-like body, and a solder component or plate thereon. A second layer made of a palladium film is interposed to prevent diffusion of the glass component of the green body, and the third layer has a gold film having excellent wettability and adhesion to solder. This window glass for optical semiconductors is hermetically fixed to the metal contact surface of the window hole provided in the optical semiconductor package of the optical semiconductor module using solder to close the window hole.
[0009]
The plate-like body is made of a material such as optical glass, borosilicate glass, quartz glass, or transparent glass ceramic that is transparent with respect to the wavelength of light emitted or received by the optical semiconductor. Even if it reaches, it is stable without thermal deformation, and materials that do not cause blowout of contained components such as alkali blowing are suitable during film deposition and for a long time thereafter, and workability such as cutting and polishing is also suitable Good material is preferred. As the shape of the plate-like body, there are a square shape, a round shape, a polygonal shape and the like depending on the shape of the window hole portion of the package, but a hexagonal shape is preferable from the manufacturing surface.
[0010]
The metal multilayer film having a three-layer structure has a chromium film, a titanium film or a nickel chromium film having a thickness of about 0.05 to 0.1 μm and excellent adhesion to glass as a first layer on the glass surface. As the second layer film laminated thereon, there is a palladium film that has a thickness of about 0.3 to 1.0 μm and stops the diffusion of the solder component or glass component, and the third layer film As described above, a gold film having a thickness of about 0.3 to 0.6 μm, good wettability with solder, and excellent adhesion is provided.
[0011]
In the optical semiconductor package, the surface material around the window hole is made of a metal material such as Kovar alloy having good wettability with solder.
[0012]
As a method of manufacturing the window glass for optical semiconductors of the present invention, a metal multilayer having a three-layer structure in which a plurality of light-transmitting portions and an unbroken ring surrounding the light-transmitting portions are formed on one surface of a plate glass having a large plane size. It is efficient to form a film and then cut it into each window glass of a predetermined size. As one of the methods for forming an annular metal multilayer film, a metal multilayer film is formed on almost the entire surface of one side of a plate glass by an existing film deposition method such as vacuum deposition or sputtering, and resists etching on the film. Use a resin photoresist solution to draw an annular masking pattern, and then remove the exposed portion of the metal multilayer film by etching to form a plurality of translucent parts arranged at predetermined intervals, then masking Can be removed by washing with a solvent or the like. As another method, a plurality of light-transmitting portions that are arranged in advance at predetermined intervals are masked to form a metal multilayer film, and then the mask is removed to attach the metal multilayer film to the light-transmitting portion. There are ways to eliminate it. The metal multilayer film is formed by depositing a first layer made of a titanium film, a chromium film or a nickel chromium film on the glass surface of the plate-like body, and forming a second layer made of a palladium film thereon. Then, a gold film is deposited as the third layer. When a plate-like body having a light-transmitting portion of plate glass and an annular metal multilayer film surrounding the light-transmitting portion is cut out as a unit, a plurality of window glasses for optical semiconductors can be manufactured. The planar shape of the window glass at the time of cutting is preferably a hexagonal shape that requires fewer processing steps than the round shape and can increase the yield.
[0013]
【Example】
FIG. 1 is an explanatory view of an optical semiconductor window glass 1 according to the present invention, in which FIG. A is a plan view and FIG. B is a cross-sectional view taken along line XX of FIG. In this figure, 1a shows a plate-like body, 2 shows a metal multilayer film having a three-layer structure, and the same parts as those shown in FIG.
[0014]
As shown in FIG. 1, an optical semiconductor window glass 1 of the present invention has a hexagonal plate-like body 1a made of borosilicate glass having a thickness of 0.3 mm and a side length of 1.5 mm. A circular translucent portion 1b having a diameter of 1.5 mm, and an annular three-layer metal multilayer film 2 is formed on a surface around the translucent portion 1b. 2 has an overall thickness of 1.1 μm, a 0.1 μm thick titanium film 2 a on the glass surface, a 0.7 μm thick palladium film 2 b interposed thereon, and a third layer thick. A gold film 2c having a thickness of 0.3 μm is provided.
[0015]
In the optical semiconductor module as shown in FIG. 2, when the optical semiconductor window glass 1 is fixed to the optical semiconductor package 3, first, instead of the adhesive 14 on the contact surface 3 b of the window hole portion 3 a of the optical semiconductor package 3. The solder 4 containing gold tin is applied in an annular shape, and the optical semiconductor window glass 1 is placed on the contact surface 3b, and the metal multilayer film 2 is placed in contact with the annular solder 4. Next, this is placed in a heating furnace (not shown) in an inert gas atmosphere, heated and heated to melt the solder 4, and the temperature is lowered to solidify the solder 4, whereby the window glass 1 is attached to the window hole 3 a of the package 3. Adheres to airtightness.
[0016]
【The invention's effect】
According to the window glass for optical semiconductors of the present invention, a highly reliable optical semiconductor module can be efficiently manufactured by airtightly fixing using solder to the metal contact surface of the window hole portion of the optical semiconductor package. This is an excellent effect.
[Brief description of the drawings]
FIG. 1 is a view showing a window glass for optical semiconductors according to the present invention, in which FIG. A is a plan view and FIG. B is a cross-sectional view taken along a line XX in FIG.
FIG. 2 is a cross-sectional view of an optical semiconductor module equipped with a conventional window glass.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical semiconductor window glass 1a Plate-shaped body 1b Translucent part 2 Metal multilayer film 2a Titanium film 2b Palladium film 2c Gold film 3 Optical semiconductor package 3a Window hole part 3b Contact surface 3d Bottom part 4 Solder 5 Plate glass

Claims (2)

In an optical semiconductor window glass fixed to a window hole portion of an optical semiconductor package, a film selected from a titanium film, a chromium film, or a nickel chromium film as a first layer on the surface of the window glass, as a second layer An optical semiconductor window glass comprising a metal multilayer film for fixation made of a palladium film and a gold film as a third layer. An optical semiconductor module comprising the window glass for an optical semiconductor according to claim 1.

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