JPH04174942A - Manufacture of voltage-dividing resistor element to be incorporated in electron tube - Google Patents

Abstract

PURPOSE:To realize trimming of withstand voltage and high accuracy by thermally treating a resistance layer at a specified temperature. CONSTITUTION:On an insulation substrate 11 made of ceramic, a resistance paste is formed with the resistance material of ruthenate lead system and then thermally treated in the air at a temperature of 800 to 1200 deg.C to form a resistance layer 13 by changing a structural state. And then the resistance layer 13 is traced by a laser beam with high accuracy. After the trimming proces, the manufacture is proceeded by an ordinary method. Thus, it is not required to form the trimming position on the resistance layer, so that the miniaturization of the voltage-dividing resistor element may be performed.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a method of manufacturing a voltage dividing resistor element for use in an electron tube such as a color cathode ray tube, and particularly relates to a method for manufacturing a voltage dividing resistor element for use in an electron tube such as a color cathode ray tube. This invention relates to a trimming process that locally modifies values.

(Prior Art) Conventionally, some electron tubes, such as color cathode ray tubes used in color television receivers, require a high voltage to be supplied to the convergence electrode, focus t+ pole, etc. in addition to the anode voltage.

In such a case, if a high voltage is supplied from the stem of the color cathode ray tube, a problem will arise in terms of withstand voltage, so a voltage dividing resistor is built into the color cathode ray tube together with the electron gun as a voltage dividing resistor element for the built-in electron tube. A method has been proposed in which the anode voltage is divided into parts to supply a high voltage to each electrode.

By the way, in the method of manufacturing a voltage dividing resistor element for use in an electron tube as described above, there is a trimming process. It is a process.

That is, the voltage dividing resistance element obtained by the conventional manufacturing method is constructed as shown in FIGS. It is being Further, a resistance layer 13 is formed in a zigzag pattern on the insulating substrate 11 in electrical contact with the extraction electrode 12, and a plurality of trimming margins 14 are formed integrally with this resistance layer 13.

In the trimming step of the manufacturing method of this voltage dividing resistor element, a sandblasting method is adopted, in which fine ceramic particles with a diameter of about 1 (μm) are injected into the trimming margin 14 using high-pressure air, etc., and this portion is partially scraped off. .

In this way, the division ratio is adjusted by changing the resistance value of the trimming margin 14.

However, trimming by sandblasting requires the formation of a trimming resistance layer called a trimming margin 14, which is an obstacle to miniaturization of the voltage dividing resistance element.

Furthermore, since fine particles made of ceramic are used, problems such as contamination of the voltage dividing resistor element and environmental pollution around the device arise due to the fine particles.

Furthermore, there is a problem in that high-speed, high-precision trimming cannot be performed in terms of movement control of the nozzle that sprays ceramic fine particles and cutting speed.

In addition to this sandblasting method, there is a trimming method using a laser beam that does not use ceramic particles. This trimming method is a method in which the resistance layer of the trimming margin 14 is sublimated by a laser beam to change the resistance value of the trimming margin 14. This trimming method is widely used in the production of hybrid ICs, etc., and allows for high-speed and high-precision trimming. can be done.

However, the spacing between the resistor layers removed by the laser beam is narrow, and when used under high voltage (approximately 32 KV) like a voltage dividing resistor element, the insulation between the trimmed resistor layers cannot be maintained, resulting in withstanding voltage. This may cause problems and cause division ratio fluctuations during actual operation.

In this regard, trimming by sandblasting allows for wide spacing between the resistor layers in the trimmed portions, and is reliable in terms of withstand voltage, so it is currently being used as a manufacturing method for voltage divider resistors for built-in electron tubes. ing.

(Problems to be Solved by the Invention) As mentioned above, in the conventional trimming method using ceramic fine particles, it is necessary to form a resistive layer for trimming, that is, a trimming margin 14 in the resistive layer pattern. This has been a problem in making piezoresistive elements smaller.

Furthermore, since ceramic particles are used, problems such as contamination of the partial voltage resistance element and environmental contamination around the device have arisen. Furthermore, there is a problem in that high-speed, high-precision trimming cannot be performed in terms of movement control of the nozzle that sprays ceramic fine particles and cutting speed. Therefore, a trimming method has been desired as an alternative to this sandblasting method.

This invention was made in view of the above circumstances, and does not require the formation of a resistive layer specifically for trimming or the use of ceramic fine particles, has excellent voltage resistance, and is capable of high-speed, high-precision trimming for built-in electron tubes. An object of the present invention is to provide a method for manufacturing a voltage dividing resistor element.

[Structure of the Invention (Means for Solving the Problem) This invention forms a lead ruthenate-based resistance layer on a ceramic insulating substrate, and locally coats this resistance layer with a
This is a method of manufacturing a voltage dividing resistor element for incorporating an electron tube, in which heat treatment is performed in the range of ~1200° C. to alter the structural state of the resistive layer, and trimming is performed using the resulting change in resistance value.

(Operation) According to the present invention, the resistance value can be partially corrected by locally altering the structural state of the resistance layer formed on the ceramic insulating substrate through heat treatment.

Therefore, there is no need to form a trimming margin in the resistance layer as in the case of using conventional methods, and there is no need to use ceramic fine particles as in the case of sandblasting. As a result, various problems such as contamination of the voltage dividing resistor element can be improved, and trimming accuracy is significantly improved.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The voltage dividing resistor element for incorporating an electron tube according to the present invention is constructed as shown in FIG. 1, as seen through the insulating coating layer forming the outer surface.

That is, the same parts as in the conventional example are denoted by the same reference numerals. Reference numeral 11 in the figure is an insulating substrate made of ceramics, and a plurality of extraction electrodes 12 are provided on the surface of the insulating substrate 11 along the periphery.
is provided. Further, on the surface of the insulating substrate 11, a lead ruthenate-based resistance layer 13 is formed in a zigzag pattern in electrical contact with the extraction electrode 12.

Next, a method for manufacturing a voltage dividing resistor element according to the present invention will be explained.

First, on the insulating substrate 11 made of ceramics, a resistance paste made of a lead ruthenate-based resistance material containing lead borosilicate glass and having a sheet resistance of about IOKΩ/mm is printed in a predetermined shape by a screen printing method and dried. Then, the lead electrode 12 in the resistance layer is formed.

Next, use a material similar to the above resistance material to obtain a sheet resistance of 1 to I.
Using a resistance paste of approximately OKΩ/4, a zigzag pattern that provides a predetermined partial pressure ratio is printed by screen printing and dried.

Thereafter, the resistive layer 13 is formed by heating and baking at 840 to 860° C. in air for about 8 to 10 minutes. The resistance layer 13 thus obtained has a total resistance value of 2 to 3 GΩ. At this time, if the partial voltage ratio at each extraction electrode 12 is not within a predetermined range, a trimming process is performed to correct it.

In this case, the trimming device (not shown)
Use a jig in which the jig in which 1 is fixed is mechanically operated. This allows the laser beam to accurately trace the top of the resistive layer 13, and allows continuous high-speed heat treatment.

Calculation of the partial pressure ratio during trimming is done by measuring the resistance value while performing heat treatment in the range of 800 to 1200 degrees Celsius with a laser beam, and the process is stopped when the predetermined partial pressure ratio is reached. There is.

The portions to be subjected to these heat treatments are determined by how the partial voltage ratio deviates, the pattern shape of the resistive layer 13, the number of partial voltage lead-out portions, and the degree of electric field concentration.

Now, the above trimming process uses a laser beam in the present invention as described above, and is carried out under the conditions shown in Table 1 below.

Table 1 In this case, the spot diameter is determined by the width of the resistance layer 13 pattern formed on the insulating substrate 11 and the amount of resistance change to be trimmed. However, if the spot diameter is increased,
The energy density becomes small, and a sufficient amount of heat cannot be obtained. Conversely, if the spot diameter is made small, the energy density becomes large, but becomes too small than the width of the resistance layer 13 pattern. Therefore, 200 to 500 (μm) is preferable.

Energy is 1. 0-10. 0 (sj/puls
e) is preferred. This is because heating is insufficient if the energy is lower than this, and if the energy is higher than this, the resistive layer 13 will sublimate, causing disconnection of the resistive layer 13 pattern.

The pulse width is the pulse width necessary to obtain a predetermined energy density with respect to the above energy. If it is smaller than 40 (μ5ec), the energy density will be too high;
), the energy density decreases.

Therefore, in this example, trimming was performed under the conditions shown in Table 2 below.

Table 2 After the trimming step, manufacturing was carried out using a commonly used method.

'By incorporating the above-mentioned trimming process, the present invention makes it possible to design a resistor pattern that eliminates the trimming margin that has traditionally been an obstacle to miniaturizing voltage dividing resistor elements. . As a result, the size of the voltage dividing resistor element could be reduced to about 92% of the conventional size.

Furthermore, it is no longer necessary to use ceramic particles, and problems such as contamination of the partial voltage resistance element and contamination of the environment around the device are solved. Furthermore, by employing the trimming process of the present invention, it was possible to manufacture a voltage dividing resistor element with high speed, high precision, and excellent withstand voltage.

[Effects of the Invention] As explained above, according to the present invention, there is no need to form a trimming margin in the resistance layer, the voltage dividing resistance element can be made smaller, and the problem of ceramic fine particles can be reduced. It is possible to solve problems such as contamination of the voltage dividing resistor element due to use and environmental contamination around the device.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a voltage dividing resistor element built into an electron tube obtained by a manufacturing method according to an embodiment of the present invention, and FIG.
(a) is a plan view showing a voltage dividing resistor element for built-in electron tube obtained by the conventional manufacturing method, and (b) is a plan view showing A- in (a).
FIG. 3 is a cross-sectional view taken along line A' and viewed in the direction of the arrow. 11... Insulating substrate, 13... Resistance layer. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A method for manufacturing a voltage dividing resistor element for use in an electron tube, in which a lead ruthenate-based resistance layer is formed on a ceramic insulating substrate, the resistance layer being locally heat-treated at a temperature in the range of 800 to 1200°C. A method for manufacturing a voltage dividing resistor element for built-in an electron tube, comprising a trimming step of locally modifying the resistance value of the resistor layer.