JP2587013B2 - Light transmission cap - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-transmitting cap that covers the outer periphery of a glass terminal on which a semiconductor chip or the like that emits laser light is mounted.

[Prior Art] A semiconductor chip for emitting a laser beam used for a CD player or the like is mounted on an upper surface of a glass terminal. A metal cap is placed over the upper periphery of the glass terminal. Then, the semiconductor chip is hermetically sealed inside an envelope formed of a glass terminal and a cap.

On the ceiling surface of the cap, a transparent window covered with a light transmitting glass made of hard glass or the like is provided. The laser light emitted from the semiconductor chip mounted on the upper surface of the glass terminal can be transmitted to the outside of the cap through a window covered with light transmitting glass.

The light transmitting glass is hermetically bonded to the ceiling surface of the cap by using a low-melting glass mainly composed of PbO and B ₂ O ₃ which is previously applied to the cap via an oxide film.

By the way, in order to transmit light such as laser light through the light transmitting glass without deteriorating its light characteristics, it is required that the surface of the light transmitting glass has extremely high cleanliness.

Therefore, when manufacturing the above cap, the cap is immersed in a cleaning bath such as pure water, and the surface of the light transmitting glass covering the window on the ceiling surface of the cap is sufficiently washed so that no foreign matter is attached. There is a need.

[Problems to be Solved by the Invention] In the above-described cap, a part of the surface of the low-melting glass in which the light transmitting glass is hermetically bonded to the ceiling surface of the cap was exposed to the outer surface of the cap.

Therefore, when the above-mentioned cap is washed by immersing it in a washing bath of pure water or the like, Pb or the like which is easily dissolved in water or the like, which is a component of the low-melting glass joining the light transmitting glass to the ceiling surface of the cap, is used. Dissolved in the washing bath. Then, Pb and the like dissolved in the cleaning bath solution adhered to the surface of the light-transmitting glass while crawling on the surface of the light-transmitting glass. Further, water droplets attached to the light transmitting glass surface of the washed cap taken out of the cleaning bath are dried on the light transmitting glass surface, and the Pb and the like contained in the water droplets remain and adhere to the light transmitting glass surface. did. Then, the degree of cleaning of the surface of the light transmitting glass was significantly reduced.

As a method for preventing Pb or the like from adhering to the light transmitting glass surface of the cap, a method of manufacturing the above cap with great care to prevent foreign matter from adhering to the light transmitting glass surface. Conceivable. And
In manufacturing the above-mentioned cap, a method of eliminating the round washing operation of the cap can be considered.

However, the above-described method of paying great attention not to attach foreign matter to the surface of the light-transmitting glass when manufacturing the cap makes the manufacturing of the cap troublesome and troublesome.

In addition, it is extremely difficult to manufacture the above-mentioned cap while preventing foreign matter such as dust from adhering to the surface of the above-mentioned light-transmitting glass at all. The operation of cleaning the surface of the transmission glass is indispensable.

Therefore, when manufacturing the above-mentioned cap, it is necessary to wash the cap entirely, and therefore, only a light-transmitting cap having a low degree of cleaning with foreign matter such as Pb adhered to the surface of the light-transmitting glass could be manufactured.

Then, the present inventors, after intensive research, in order to solve such problems, when the above cap is immersed and washed in a washing bath such as pure water, using some means, The present inventors have conceived that it is sufficient to prevent the components such as Pb from being eluted into the cleaning bath solution from the low melting point glass in which the light transmitting glass is bonded to the ceiling surface of the cap.

Then, by doing so, the cap is immersed in a washing bath of pure water or the like and washed in a round manner, thereby completely removing foreign substances such as dust adhering to the surface of the light transmitting glass during the manufacture of the cap. Thus, the present inventors have conceived that it is possible to manufacture a light transmitting cap having an extremely high degree of cleaning of the light transmitting glass surface.

That is, in the present invention, when the cap is immersed in the washing bath and washed, Pb and the like of the constituents thereof elute from the low-melting glass joining the light transmitting glass to the ceiling surface of the cap into the washing bath liquid. An object of the present invention is to provide a light-transmitting cap (hereinafter, referred to as a cap) that can be washed without fear.

[Means for Solving the Problems] In order to achieve the above object, a cap according to the present invention is a light transmitting cap in which light transmitting glass is bonded to a cap body using low melting point glass. The exposed surface portion of the low-melting glass is covered with a protective film made of an organic substance that prevents components of the low-melting glass from being eluted.

In the cap of the present invention, it is preferable that the protective film is a lacquer.

[Operation] In the cap of the present invention, when the cap is immersed and washed in a washing bath of pure water or the like, a protective film made of an organic material covering a surface portion of the low-melting glass exposed on the outer surface of the cap, A cleaning bath such as pure water can be prevented from contacting the surface of the low melting point glass exposed on the outer surface of the cap.

Then, from the surface portion of the low-melting glass exposed on the outer surface of the cap, the low-melting glass is easily dissolved in water or the like as a component of the low-melting glass.
Pb and the like can be prevented from being eluted in a cleaning bath such as pure water and adhered to the surface of the light transmitting glass.

At the same time, from the surface of the low-melting glass exposed on the outer surface of the cap, Pb or the like, which is a component of the low-melting glass, which is easily dissolved in water, etc., elutes into a cleaning bath such as pure water, and the low-melting glass erodes. And can be prevented from being altered. Then, it is possible to prevent the bonding strength of the low-melting glass connecting the light transmitting glass to the cap from lowering, and to prevent the airtightness of the joint between the light transmitting glass and the cap from being impaired.

Example Next, an example of the present invention will be described with reference to the drawings.

1 and 2 show a preferred embodiment of a cap according to the present invention. FIG. 1 is a sectional view of the cap, and FIG. 2 is an enlarged sectional view of a low melting point glass portion of FIG. Hereinafter, this cap will be described.

In the figure, reference numeral 1 denotes a hat-shaped metal cap.

On the ceiling surface 5 of the cap, a large-diameter circular window 6 is opened. The window 6 is covered from the inside with a light transmitting glass 2 made of a hard glass or the like that transmits light such as a disk-shaped laser beam. The periphery of the light transmitting glass 2 is hermetically bonded to the ceiling surface 5 of the cap using low-melting glass 3 containing PbO, B ₂ O ₃ as a main component.

The above configuration is the same as that of the conventional cap, but in the cap shown in the figure, as shown in FIG. 2, the surface portion 3a of the low melting point glass exposed on the outer surface of the cap, that is, the light transmitting glass inside the cap 1 The surface portion 3a of the low-melting glass exposed around 2 and the surface portion 3a of the low-melting glass exposed inside the window 6 on the ceiling surface of the cap 1 are covered with a protective film 4 made of an organic substance. For the protective film 4, for example, a lacquer 4a or the like is used.

The cap shown in FIGS. 1 and 2 is configured as described above. In this cap, when the cap is immersed in a washing bath and washed, the low-melting glass exposed on the outer surface of the cap. A protective film 4 made of an organic material covering the surface portion 3a prevents the pure water of the cleaning bath solution from contacting the surface portion 3a of the low melting point glass exposed on the outer surface of the cap.

Then, the protective film 4 covering the surface portion 3a of the low melting point glass.
However, Pb or the like, which is a component of the low-melting glass 3 and is easily dissolved in water or the like, elutes into the cleaning bath solution and covers the window 6 on the ceiling surface of the cap immersed in the same cleaning bath solution. Prevent sticking.

At the same time, Pb or the like, which is a component of the low-melting glass 3 and easily soluble in water, etc., elutes from the surface portion 3a of the low-melting glass exposed on the outer surface of the cap into a cleaning bath such as pure water, and the low-melting glass 3 The protective film 4 that covers the surface portion 3a of the low-melting glass prevents the erosion and the deterioration of the material 3.

[Effects of the Invention] As described above, according to the cap of the present invention, when the cap is immersed in a cleaning bath such as pure water for cleaning, the cap is exposed to the surface of the low-melting glass exposed on the outer surface of the cap. The contact of the cleaning bath with a protective film made of organic material.
It can be reliably prevented.

And it is easy to dissolve in water, etc., a constituent of low melting glass
Pb and the like can be reliably prevented from being eluted into the cleaning bath solution and attached to the surface of the light transmitting glass covering the window on the ceiling surface of the cap immersed in the same cleaning solution.

At the same time, from the surface of the low-melting glass exposed on the outer surface of the cap, Pb or the like, which is a component of the low-melting glass, which is easily dissolved in water, etc., elutes into a cleaning bath such as pure water, and the low-melting glass erodes. And can be prevented from being altered. Then, it is possible to prevent the bonding strength of the low-melting glass connecting the light transmitting glass to the cap from lowering, and to prevent the airtightness of the joint between the light transmitting glass and the cap from being impaired.

As a result, according to the cap of the present invention, the cap can be immersed and washed in a cleaning bath of pure water or the like with ease and ease. Then, the surface of the light transmitting glass covering the window on the ceiling surface of the cap can be sufficiently and accurately cleaned so that foreign matter such as dust does not adhere. Then, a light transmitting cap with an extremely high degree of cleaning of the light transmitting glass surface can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view of the cap of the present invention, and FIG. 2 is an enlarged sectional view of the low melting point glass portion of FIG. 1 ... Cap, 2 ... Light transmitting glass, 3 ... Low melting point glass,
3a: Surface part of low melting glass exposed on the outer surface of the cap,
4 ... Protective film made of organic substance, 4a ... Lacquer.

Claims (2)

(57) [Claims] 1. A light transmitting cap in which a light transmitting glass is joined to a cap body using a low melting point glass, and a surface portion of the low melting point glass exposed on an outer surface of the cap is used to dissolve components of the low melting point glass. A light-transmitting cap, which is covered with a protective film made of an organic substance that prevents the light. 2. The light transmitting cap according to claim 1, wherein the protective film is a lacquer.