JPH0355742A - Manufacture of electron tube - Google Patents

Abstract

PURPOSE:To eliminate the possibility of sealing a gas into an electron tube with a simple device and process by vacuuming a glass enclosure and a space between a vacuum vessel and the glass enclosure in the vacuum vessel having a size sufficient to enclose the glass outside, and heating a semiconductor crystal from the outside. CONSTITUTION:A glass enclosure 10 of electron tube is enclosed with a bell jar 12 and a table 14, a vacuuming glass tube 16 is disposed through the table 14, and the enclosure 10 is fused and connected to the top end of the glass tube 16 in the communicated state, and the enclosure 10 is vacuumed through the tube 16 by a vacuum pump. The space around the enclosure 10 formed by the bell jar 12 and the table 14 is vacuumed from an exhaust hole 18 formed on the table 14. Under this state, a semiconductor crystal 20 mounted on the top end inner surface of the glass enclosure 10 is heated from the outside of the bell jar 12 by an infrared lamp 22.

Description

[Detailed description of the invention] [Industrial application field]

This invention relates to a method for manufacturing an electron tube having a semiconductor crystal photoelectric structure bonded to the inner open surface of a glass envelope.

[Conventional technology]

There is an electron tube in which a semiconductor crystal bonded to glass is placed inside a glass envelope, and this serves as a semiconductor crystal photocathode. Generally, in the surface activation process for forming a photocathode, a semi-rod crystal must be placed in a vacuum and heated to approximately 600 to 640"C to clean the surface, but this process does not allow the semiconductor crystal to adhere. Glass is, for example, GaAs/G
a AJ! In the case of As semiconductor crystals, a glass having a coefficient of thermal expansion similar to these, such as Corning 7056 (trade name), is used. This glass softens under the above-mentioned temperature conditions of about 600 to 640°C, which are necessary for cleaning the semiconductor crystal surface. Therefore, for example, if the inside of an electron tube is set to a vacuum and the outside is set to normal pressure, the glass of the electron tube will be deformed due to the pressure difference between the inside and outside. For this reason, when forming a photocathode on an electron tube, it must be done in a vacuum. Conventionally, in the manufacturing method of such an electron tube, a semiconductor crystal is bonded to a glass face plate, and this is placed as a component of the electron tube in the same large vacuum device at the same time as other components. After heating the crystal and cleaning its surface, use Cs and 02 to make the electron affinity of the surface low, zero, or negative, thereby making it a photocathode. The parts are integrated with a sealing material such as indium at required points to maintain a vacuum.

[Problem to be solved by the invention]

Conventional electron tube like above! ! ! This method involves bringing multiple parts, including the photocathode, into a large vacuum device and assembling them with a magic hand, which is a complex and costly process and equipment.Furthermore, in the final process, each It is necessary to maintain a vacuum between the parts by interposing a sealing material between them, but if the gas released from the sealing material such as indium is not sufficiently removed during sealing,
There is a problem in that gas remains inside the electron tube and deteriorates the characteristics of the electron tube. The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method for manufacturing an electron tube using simple equipment and processes, at low cost, and without the risk of trapping gas within the electron tube. Suppose that (Meaning for Solving the Problems V1) The present invention provides a method for manufacturing an electron tube in which a semiconductor crystal photocathode is formed from a semiconductor crystal adhered to the inner surface of a glass envelope, in which an external measurement of the glass envelope is performed. It is surrounded by a removable vacuum container, and a glass tube for drawing a vacuum from the glass envelope is placed through the vacuum container, and a vacuum is drawn from this glass tube and the vacuum container. The above object is achieved by heating the semiconductor crystal from the outside of the container.Also, the vacuum container has a diameter larger than the outer diameter of the glass envelope, and the glass tube is in a sealed state. The above object is achieved by having a simple bottomed shape with an opening at one end of the table to be penetrated and a size for enclosing a glass envelope, and the end surface on the opening side is removably attached to the table in a sealed state. Furthermore, the above object is achieved by forming an exhaust hole in the table to evacuate the inside of the vacuum container.Furthermore, the semiconductor crystal is removed from the outside of the vacuum container. The above object is achieved by heating with infrared light.Furthermore, a developing body is placed in the opening of the vacuum container at a position relative to the semiconductor crystal, thereby ripening the semiconductor crystal. In this way, the above object is achieved. Also, the glass envelope is melted in communication with the tip of the glass tube passing through the table, the semiconductor crystal is cleaned by heating, and the CS, adsorbs 02, CS, O2
After forming the layer, the glass envelope is separated from the glass tube by melting the tip of the glass tube and sealing it in a vacuum, thereby achieving the above object. [Function] In this invention, in a vacuum container large enough to surround the outer circumference of the glass envelope, both the glass envelope and between the vacuum container and the glass envelope are evacuated, and the outer circumference of the glass envelope is evacuated. By heating a semiconductor crystal from a semiconductor crystal, it is possible to easily form a photocathode and manufacture an electron tube in a small vacuum container without using large-scale equipment, and there is no need for a sealing material such as indium. Therefore, the process is simplified, and it is possible to prevent gas from being trapped in the electron tube and the resulting significant deterioration of characteristics.

【Example】

The method for manufacturing an electron tube according to the present invention will be explained in detail below with reference to the drawings showing an apparatus for carrying out the method. In this embodiment, the outside of the glass envelope 10 of the electron tube is surrounded by a bell jar 12 and a table 14, and a glass tube 16 for evacuation is placed through the table 14. The glass envelope 10 is melt-connected to the tip in a communicating state, the inside of the glass envelope 10 is evacuated with a vacuum pump from the glass tube 16, and the glass envelope 10 formed by the bell jar 12 and the table 14 is further connected to the glass envelope 10. The space around the glass envelope 10 is evacuated through an exhaust hole 18 formed in the table 14, and in this state, the glass envelope 1
The semiconductor crystal 20 attached to the opening inside the tip of the bell jar 12 is heated from the outside of the bell jar 12 by an infrared lamp 22. The reference numeral 24 in the figure indicates an O-ring for sealing between the glass tube 16 and the table 14, and the reference numeral 26 indicates an O-ring for sealing between the table 14 and the open end surface of the bell jar 12. The table 14 includes a glass envelope 1
0 is not attached, insert it into the glass tube 16 and fix it. The glass envelope 10 is fused and connected to the tip of a glass tube 16 protruding from the table 14 in a communicating state. In this state,
With the bell jar 12 surrounding the glass envelope 10, as shown in FIG.
The open end of the bell jar 12 is brought into close contact with the bell jar 1.
Set 2. In this state, the inside of the glass envelope 10 is evacuated through the glass tube 16, and the open space inside the bell jar 12 around the glass envelope 10 is evacuated through the exhaust hole 18. When a predetermined vacuum pressure is reached, the semiconductor crystal 20 is heated from the outside of the glass envelope 10 and bell jar 12 by the infrared lamp 22 to clean the surface of the semiconductor crystal 20. The step of adsorbing CS and 02 onto the surface of the semiconductor crystal 20 is carried out in the usual manner from a glass tube 16. FIG. 2 shows the semiconductor crystal photocathode 21 in a perfect state adhered to glass. In FIG. 2, the glass IOA is a part of the glass envelope 10, and for example, the aforementioned Corning 7056 is used. The semiconductor crystal 20 includes a Si02 layer 2OA,
It is composed of a GaAJ2As layer 20B and a GaAs layer 20C, and after cleaning by heating, Cs and O2 are adsorbed thereto to form a Cs,02 layer 21A, thereby completing a semiconductor crystal photocathode 21. In addition, in the above embodiment, the bell jar 12 and the table 14
As a result, the glass envelope 1 is opened with the glass tube 16 passing through it.
0, the glass tube 16 passes through it, and the glass envelope 10 surrounds the glass tube l6.
Any vacuum container may be used as long as it surrounds the glass envelope 10 so as to be detachable from the glass envelope 10. Furthermore, in the above embodiment, the semiconductor crystal 20 is used as the bell jar 12.
Heating is performed from the outside by an infrared lamp 22, for example, at two points in FIG. As shown by the chain line, a heating element such as a heat block 30 may be arranged to heat the semiconductor crystal 20 from there. In this case, since the semiconductor crystal 20 is heated only through the glass IOA on the bottom of the glass envelope 10 without going through the bell jar 12, efficient heating can be performed and the bell jar 12 can be The advantage is that there is no need to consider the aging resistance of the glass.

【Effect of the invention】

Since the present invention is constructed as described above, it has the advantage that an electron tube having a semiconductor crystal photocathode with excellent characteristics can be manufactured easily and at low cost without going through large-scale equipment or complicated processes. It has a beneficial effect.

[Brief explanation of drawings]

FIG. 1 shows Il! of the electron tube according to the present invention. FIG. 2 is an enlarged sectional view showing a semiconductor crystal photocathode in an electron tube manufactured by the method of the present invention. 10...Glass envelope, l2...Bell jar 1
4...Table, l6...Glass tube, 18.
...Exhaust hole, 20...Semiconductor crystal, 21.
...Semiconductor crystal photocathode, 22...Infrared lamp, 30...Beat block.

Claims (6)

[Claims] (1) In a method for manufacturing an electron tube in which a semiconductor crystal photocathode is formed from a semiconductor crystal adhered to the inner surface of a glass envelope, the outside of the glass envelope is surrounded by a detachable vacuum container, and the glass A glass tube for evacuation from the envelope is placed through the vacuum container, the glass tube and the vacuum container are evacuated, and the semiconductor crystal is heated from outside the glass envelope. Characteristic electron tube manufacturing method. (2) In claim 1, the vacuum container includes a table having an outer diameter larger than the outer diameter of the glass envelope and through which the glass tube is passed through in a sealed state, and a table having an open end and extending from the glass envelope. 1. A method for manufacturing an electron tube, comprising: a bell gear having a bottomed cylindrical shape of a size that accommodates the electron tube, and whose open end surface is removably attached to the table in a sealed state. (3) The method of manufacturing an electron tube according to claim 2, wherein an exhaust hole for evacuating the inside of the vacuum container is formed in the table. (4) A method of manufacturing an electron tube according to claim 1, 2 or 3, characterized in that the semiconductor crystal is heated with infrared light from outside the vacuum container. (5) In claim 1, 2 or 3, a heating element is arranged inside the vacuum container at a position relative to the semiconductor crystal,
A method for manufacturing an electron tube, characterized by heating a semiconductor crystal thereby. (6) In any one of claims 1 to 5, the glass envelope comprises:
The tip of the glass tube passing through the table is fused and connected in a communicating state, the semiconductor crystal is cleaned by heating, and Cs
, O_2 is adsorbed to form a Cs, O_2 layer, and then the glass envelope is sealed in a vacuum state by melting the tip of the glass tube, and is separated from the glass tube. Method.