JPH11102806A - Manufacture of thick-film resistor for high voltage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thick-film resistor for high voltage, which can be sufficiently downsized and by which decrease in yield due to failed separation of substrate or insulating glass is prevented. SOLUTION: In a step 26 for forming an insulating glass layer, an insulating glass layer 18 with a single pattern which covers multiple thick-film resistor layers 16 formed on a common substrate 20 in a step 24 for forming thick-film resistor layers, and the common substrate 20 is cut along cutting lines which are positioned in advance between the thick-resistor layers 16. Thick-film resistors 10 for high voltage are separated from each other, accordingly. In this way, there is no longer any need for ensuring margins larger than a specified value between the perimeter of the thick-film resistor layers 16 and borders of each substrate 12 and the device can be miniaturized. Also, since the thick- film resistors 10 are separated from each other by a cutting grinder 30, decrease in yield due to failed separation of substrate or chipping insulating glass can be prevented advantageously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage thick-film resistor in which a thick-film resistance layer is fixed on a ceramic substrate and the thick-film resistance layer is covered with a relatively thick insulating glass layer for preventing creeping discharge. And a method for producing the same.

[0002]

2. Description of the Related Art A thick film resistance layer is fixed on a ceramic substrate, and a relatively thick insulating glass layer for preventing creeping discharge of about 100 to 600 nm is used to prevent creeping discharge of the thick film resistance layer. Is known as a high-voltage thick film resistor covered by a thin film. For example, JP-A-53-86350
And a high-voltage resistor described in JP-A-1-232643.

In order to reduce the manufacturing cost, a high-voltage thick film resistor as described above is provided with a plurality of longitudinal patterns in parallel with each other on a relatively large common substrate for multi-cavity production. After the thick film resistance layer, the terminal conductor layer connected to both ends thereof, and the plurality of insulating glass layers respectively covering the plurality of thick film resistance layers are formed by thick film printing and thick film baking, respectively, It is generally manufactured by dividing a common substrate for individual cutting along the break groove.

[0004]

If, for example, the electron gun inserted into the cathode ray tube becomes smaller due to the smaller diameter of the above-mentioned cathode ray tube, there is a demand for a smaller high-voltage thick film resistor attached thereto. It was started. Therefore, each of the common substrate and the plurality of thick film resistance layers formed thereon, the terminal conductor layers connected to both ends thereof, and the plurality of insulating glass layers respectively covering the plurality of thick film resistance layers. It has been practiced to manufacture small high-voltage thick-film resistors by sequentially reducing the pattern at the same rate. However, when each pattern is made smaller in this way, the outer edge of the thick-film resistance layer and the edge of each substrate may be reduced due to dripping during printing or firing during firing, particularly due to the large thickness of the insulating glass. In this case, it is necessary to ensure a margin between the predetermined value and the predetermined value or more, which is an obstacle to miniaturization. Further, if the margin is to be further reduced, the insulating glass may flow into the break groove of the common substrate, and there is a disadvantage that a substrate division defect or a defect of the insulating glass is generated, thereby lowering the yield.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-voltage power supply which can be sufficiently miniaturized and has no yield loss caused by defective substrate division or insulating glass. An object of the present invention is to provide a method for manufacturing a thick film resistor.

[0006]

The gist of the present invention to achieve this object is that a thick-film resistance layer having both ends connected to a thick-film conductor layer for terminals is fixed on a ceramic substrate. A method for manufacturing a high-voltage thick-film resistor, wherein the thick-film resistance layer is covered with a relatively thick insulating glass layer for preventing creeping discharge, wherein (a) on a common substrate sufficiently larger than the ceramic substrate. A thick-film conductor layer forming step of forming a plurality of sets of the thick-film conductor layers; and (b) forming a plurality of elongated thick-film resistance layers on the common substrate in a state where they are arranged in parallel. A film resistance layer forming step;
(c) forming an insulating glass layer on the plurality of thick-film resistive layers formed in the thick-film resistive layer forming step to form a single-pattern insulating glass layer that simultaneously covers the plurality of thick-film resistive layers; After the step (d), a single pattern insulating glass layer is formed on the plurality of thick film resistance layers by the insulating glass layer forming step, it is preset so as to be located between the thick film resistance layers. Cutting the common substrate along the cut line thus separated to separate the high-voltage thick film resistors from each other.

[0007]

As described above, in the insulating glass layer forming step, the plurality of thick film resistance layers are formed on the plurality of thick film resistance layers formed by the thick film resistance layer forming step on the common substrate. After a single-pattern insulating glass layer is simultaneously formed, the common substrate is cut along a dividing line preset to be located between the thick-film resistive layers, thereby forming a high-voltage thick film. The resistors are separated from each other. Therefore, it is not necessary to secure the margin between the outer edge of the thick-film resistance layer and the edge of each substrate to a predetermined value or more for dripping of the insulating glass layer or dripping at the time of firing, so that downsizing can be achieved. Becomes In addition, the insulating glass layer and the common substrate are cut rather than broken to separate the individual high-voltage thick film resistors from each other. Reduction is suitably prevented.

[0008]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show a plan view and a side view of a high-voltage thick-film resistor 10 built in a cathode ray tube and attached to an electron gun. This high-voltage thick film resistor 1
Numeral 0 denotes a pair of thick film conductor layers 14 having a rectangular pattern to function as terminals on a relatively small longitudinal ceramic substrate 12 made of alumina, forsterite, steatite, high melting point glass or the like. And a thick-film resistance layer 16 having a longitudinal pattern having both ends connected to the pair of thick-film conductor layers 14 and having a smaller width dimension than the thick-film conductor layer 14, and a thick film for preventing creeping discharge. A relatively thick insulating glass layer 1 covering the entire resistance layer 16
8 are fixed by using thick film printing and thick film baking, respectively.

The ceramic substrate 12 of the high-voltage thick-film resistor 10 is provided with a thick-film conductor layer 14, a thick-film resistor layer 16, and an insulating glass layer 1 in the manufacturing process of the high-voltage thick-film resistor 10.
8 is cut out from a relatively large common substrate by cutting, the margin A between the outer edge of the thick film conductor layer 14 and the outer edge of the ceramic substrate 12, and the outer edge of the thick film resistance layer 16 and the ceramic The margin B between the outer edge of the substrate 12 and the outer edge is extremely small. Further, since the insulating glass layer 18 is fixed on the common substrate in one pattern that simultaneously covers the plurality of thick-film resistance layers 16, the insulating glass layer 18 in the width direction of the ceramic substrate 12 is formed. There is no blank space between the outer edge and the outer edge of the ceramic substrate 12.

The high-voltage thick film resistor 10 configured as described above is manufactured through, for example, a plurality of steps shown in FIG. First, as shown in FIG. 4, a relatively large common substrate 20 having the same thickness as the ceramic substrate 12 but having an area of several tens of the ceramic substrates 12 is prepared. The common substrate 20 is not provided with a break groove (break groove) as in the related art.

Next, in a thick film conductor layer forming step 22, silver-
Palladium, silver-platinum, gold, a plurality of sets of thick film conductor layers 14 are screen-printed using a thick film conductor paste containing a conductive metal powder such as ruthenium oxide having a low resistance as a main component. After being coated on the common substrate 20 and dried, for example, 8
By firing at a temperature of about 50 ° C., a plurality of sets of thick film conductor layers 14 having a thickness of about 10 μm are formed on the common substrate 20.
Is formed.

In a subsequent thick film resistance layer forming step 24, a thick film resistor paste mainly composed of a high resistance metal oxide powder such as ruthenium oxide having a stable high resistance value even under a high voltage or a high voltage pulse. After a plurality of thick-film resistance layers 16 are applied on the common substrate 20 and dried by screen printing between the pair of thick-film conductor layers 14 in a longitudinal pattern using By baking at a temperature of, for example, about 850 ° C. using a thick-film baking furnace that is not used, a plurality of thick-film resistance layers 16 having a thickness of about 10 to 20 μm are formed in parallel on the common substrate 20. . FIG. 5 shows this state. The pattern and thickness of the thick film resistance layer 16 are determined in advance so as to have a resistance value of, for example, about 50 Mohm.

In the next insulating glass layer forming step 26, the plurality of parallel thick film resistive layers 16 are formed using an insulating glass paste mainly containing an insulating material such as lead borosilicate glass.
Is screen-printed with one common pattern that simultaneously covers the plurality of thick-film resistance layers 16, after which the insulating glass layer 18 is applied and dried, using a thick-film firing furnace (not shown), for example. By firing at a temperature of about 550 ° C., an insulating glass layer for protecting them on a plurality of thick-film resistance layers 16 with a thickness of about 100 to 600 μm and suppressing creeping discharge when a high voltage is applied. 18 are formed. 6 and 7 show this state. Since the insulating glass layer 18 is thicker than a general insulating glass layer or a protective glass layer, the screen printing and firing are performed a plurality of times as necessary.

In the next cutting step 28, the above step 22,
The common substrate 20 on which the thick film conductor layer 14, the plurality of thick film resistance layers 16, and the insulating glass layer 18 are formed by the layers 24 and 26
In contrast, a cutting device (not shown) provided with a cutting grindstone 30 driven in rotation is used to set a cutting line set between the thick film resistance layers 16, for example, as shown by a dashed line in FIG. By being cut along C,
The high voltage thick film resistors 10 are separated from each other. FIG. 8 shows this state. The cutting grindstone 30 is configured in the same manner as that used for a dicing machine for cutting a semiconductor wafer, for example.
It is a well-known thing that can be cut in m width.

In the inspection step 32, the high-voltage thick film resistors 10 individually separated in the cutting step 28 are separated.
Are inspected, and those that pass those inspections are shipped.

As described above, according to the present embodiment, in the insulating glass layer forming step 26, the plurality of thick film resistance layers 16 formed on the common substrate 20 by the thick film resistance layer forming step 24 are formed. After the insulating glass layer 18 having a single pattern covering the plurality of thick film resistive layers 16 is formed at the same time, the insulating glass layer 18 is shared along a cutting line C set in advance so as to be located between the thick film resistive layers 16. By cutting the substrate 20, the high-voltage thick film resistors 10 are separated from each other. Therefore, it is not necessary to secure a margin between the outer edge of the thick-film resistance layer 16 and the edge of each substrate 12 to a predetermined value or more due to dripping of the insulating glass layer 18 or dripping during firing.
The size can be reduced. In addition, each thick film resistor for high voltage 1
The insulating glass layer 18 and the common substrate 20 are not broken in order to separate
Since the cutting is performed at 0, a decrease in the yield due to a defective substrate division or a defective defective insulating glass is suitably prevented.

When the high-voltage thick film resistor 10 has a resistance of 50 M (mega) ohm, a resistor paste having a sheet resistance (area resistance) of 1 M ohm / square (square) is used. Layer 16 has a width of 0.4 mm and a length of 2
0 mm. The width dimension of the ceramic substrate 12 on which the thick-film resistance layer 16 having such dimensions is formed depends on the thickness of the thick-film resistance layer 16.
0.8 mm to 1.2 mm
Becomes The longitudinal dimension of the ceramic substrate 12 is 23 to 24 mm when the arrangement dimension of the thick film conductor layer 14 needs to be about 1.3 mm. If the sheet resistance value of the thick film resistor layer 16 is increased, the high voltage thick film resistor 10 can be further miniaturized.

Conventionally, as shown in FIG. 9, on a common substrate 52 having a break groove 50, the above-mentioned thick film conductor layer is formed in individual regions sandwiched or surrounded by the break groove 50. A thick-film conductor layer (not shown) and a thick-film resistance layer 54 are formed by the same steps as the step 22 and the thick-film resistance layer forming step 24, and then a plurality of covering the thick-film resistance layer 54 in the respective regions. The insulating glass layer 56 was formed by the same process as the insulating glass layer forming process 26 in the rectangular pattern of. By breaking the common substrate 52 along the break grooves 50, the individual high voltage thick film resistors 58 are manufactured separately from each other. For this reason, when trying to reduce the size of the high-voltage thick film resistor 58, the outer edge of the thick film resistor layer 54 and the outer edge of the thick film It is necessary to ensure a margin D between the edge of the substrate (break groove 50) and a predetermined value or more, which is an obstacle to miniaturization. Also, the margin D
Is further reduced as shown in FIG.
The insulating glass layer 56 sometimes flows into the break groove 50 of the common substrate 52, and when the common substrate 52 is broken, there is an inconvenience that a substrate division defect or a chipping defect of the insulating glass occurs to lower the yield. .

While the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, the high-voltage thick-film resistor 10 of the above-described embodiment has a single thick-film resistor layer 16 having a thick-film conductor layer 14 connected to both ends and fixed to one surface of a ceramic substrate 12. However, the ceramic substrate 12 may be provided with three or more thick film conductor layers 14 in its longitudinal direction and a plurality of thick film resistance layers connected in series between them. A plurality of thick-film resistance layers may be fixed in parallel on one surface or both surfaces of the ceramic substrate 12.

The high-voltage thick film resistor 10 described above includes:
Although the thick film resistance layer 16 having a longitudinal pattern smaller in width than the thick film conductor layer 14 is formed, the thick film resistance layer 16 is a sinusoidal pattern or the like in which the width direction of the ceramic substrate 12 is the amplitude direction. There is no problem.

In the above-described step shown in FIG. 3, a thick-film resistor layer forming step 24
Has been described, but the thick film conductor layer forming step 22 may be performed after the thick film resistor layer forming step 24.

In the step shown in FIG. 3 described above, in the thick film conductor layer forming step 22, the thick film resistor layer forming step 24, and the insulating glass layer forming step 26, screen printing and thick film baking are respectively performed. However, depending on the characteristics of the thick film material and the like, a plurality of print layers may be fired simultaneously, for example, the thick film conductor layer 14 and the thick film resistance layer 16 may be fired simultaneously. In such a case, the thick film conductor layer forming step 22
, The baking of the thick film is unnecessary.

The thick-film conductor layer 14 and the thick-film resistance layer 16 in the above-described embodiment are formed on the common substrate 20 in a plurality of sets or patterns separated by the number corresponding to the separated high-voltage thick-film resistors 10. Although a plurality of layers are formed, similarly to the insulating glass layer 18, the thick film conductor layer 14 or the thick film resistance layer 1 is formed.
6 may be formed on the common substrate 20 in a striped pattern extending in the width direction of the ceramic substrate 12. In this case, in the cutting step 28, the thick film conductor layer 14 or the thick film resistance layer 16 and the insulating glass layer 18 are connected to the common substrate 20.
Is cut off.

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating the configuration of a high-voltage thick film resistor according to an embodiment of the present invention.

FIG. 2 is a side view showing the high-voltage thick film resistor of the embodiment of FIG.

FIG. 3 is a process chart for explaining a process of manufacturing the high-voltage thick film resistor of FIGS. 1 and 2;

FIG. 4 is a view showing a common substrate used in an initial step of FIG. 3;

5 is a cross-sectional view showing a common substrate and a thick-film resistance layer formed thereon in the thick-film resistor layer forming step of FIG. 3;

6 is a cross-sectional view showing a common substrate and a thick-film resistance layer and an insulating glass layer formed thereon in the insulating glass layer forming step of FIG. 3;

FIG. 7 is a plan view showing a common substrate and a thick-film resistance layer and an insulating glass layer formed thereon in the insulating glass layer forming step of FIG. 3;

FIG. 8 is a view for explaining a cutting state of the common substrate in the cutting step of FIG. 3;

FIG. 9 is a diagram showing a common substrate in an insulating glass layer forming step in a conventional high voltage thick film resistor.

FIG. 10 is a view corresponding to FIG. 9 showing a common substrate in a conventional insulating glass layer forming step when the high-voltage thick film resistor is miniaturized.

[Explanation of symbols]

 10: High-voltage thick film resistor 12: Ceramic substrate 14: Thick film conductor layer 16: Thick film resistor layer 18: Insulating glass layer 20: Common substrate 22: Thick film conductor layer forming step 24: Thick film resistor layer forming step 26: insulating glass layer forming step 28: cutting step

Continued on the front page (72) Inventor Takuo Nagata 3-36 Noritakeshinmachi, Nakamura-ku, Nagoya-shi, Aichi Noritake Co., Ltd.

Claims (1)

[Claims] 1. A thick-film resistance layer having both ends connected to a thick-film conductor layer for a terminal is fixed on a ceramic substrate, and the thick-film resistance layer is formed by a relatively thick insulating glass layer for preventing creeping discharge. A method of manufacturing a covered high-voltage thick film resistor, comprising: a thick-film conductor layer forming step of forming a plurality of sets of the thick-film conductor layers on a common substrate sufficiently larger than the ceramic substrate; A thick-film resistance layer forming step of forming a plurality of longitudinal thick-film resistance layers in a state where they are arranged in parallel on a substrate; and a plurality of thick-film resistance layers formed by the thick-film resistance layer forming step. An insulating glass layer forming step of forming a single-pattern insulating glass layer covering the plurality of thick-film resistance layers simultaneously; Formed on the film resistance layer Cutting the common substrate along a cutting line preset so as to be located between the thick film resistor layers, thereby separating the high voltage thick film resistors from each other. A method for producing a high-voltage thick film resistor, comprising: