JP2966215B2 - Manufacturing method of fixed resistor for high voltage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a high-voltage fixed resistor having a fixed resistor including a trimming resistor printed on the surface of an insulating substrate.

[0002]

2. Description of the Related Art A fixed resistor for high voltage is used as a bleeder resistor of a variable resistor for high voltage called a focus pack connected to a flyback truss and a high voltage side.
FIG. 3 shows a conventional method of manufacturing such a high-voltage fixed resistor. First, as shown in FIG. 3A, a first fixed resistor R1 and a second fixed resistor R2 including a trimming resistor Rt are printed on a single insulating substrate 1 made of ceramic in a predetermined pattern. A printed resistor substrate 2 is prepared, which is formed and has electrodes T1 to T3 that can be soldered to the ends of each fixed resistor. Next, a trimming process is performed on the trimming resistor Rt of the printed resistor substrate to obtain a voltage division ratio (R1 / R1 + R2). Thereafter, as shown in FIG. 3C, the electrodes T1 to T3
After the lead wire 3 is connected by soldering to FIG.
As shown in (D), the whole is insulated and covered with an insulating resin material such as epoxy resin while leaving the end of the lead wire 3.

[0003] Such a high-voltage fixed resistor in which all the fixed resistors are formed on one insulating substrate is easy to manufacture, but as the applied voltage increases, the fixed resistor between the patterns of the fixed resistors increases. In order to prevent the occurrence of discharge, the size of the insulating substrate must be increased. However, the larger the insulating substrate, the more easily the insulating substrate is damaged. Therefore, in applications where a high-voltage fixed resistor is embedded in hard resin, such as a flyback transformer,
Cracks occur in the insulating substrate due to the stress of the hard resin, and cracks occur in the insulating coating layer covering the insulating substrate, causing a problem that the characteristics of the high-voltage fixed resistor are affected.
Therefore, it has been proposed to form a fixed resistor for high voltage by dispersing and forming fixed resistors on a plurality of insulating substrates and connecting the fixed resistors on each insulating substrate with a connection conductor.

[0004]

In the case where fixed resistors are dispersedly formed on a plurality of insulating substrates, the resistance value differs depending on the combination of the insulating substrates, so that trimming is always required. However, the work of trimming a plurality of insulating substrates connected by the connection conductor is extremely poor in workability, and excessive force is applied to the connection portion of the connection conductor during the trimming work or during transportation for the trimming work, There was a problem of poor connection.

An object of the present invention is to provide a method of manufacturing a high-voltage fixed resistor that can easily perform a trimming operation even when a high-voltage fixed resistor is formed by a plurality of insulating substrates.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a method of manufacturing a high-voltage fixed resistor having a fixed resistor including a trimming resistor printed on the surface of an insulating substrate. A printed resistor substrate is prepared by printing on a substrate a first fixed resistor including at least a trimming resistor and a second fixed resistor or an n-th fixed resistor electrically connected. Next, after trimming the trimming resistor of the first fixed resistor, the printed resistor substrate is divided into first to n-th insulating substrates each having the first to n-th fixed resistors. Then, the first insulating substrate to the n-th insulating substrate
The first to n-th fixed resistors formed on the insulating substrate are electrically connected in series via connection conductors.

[0007]

First, all the fixed resistors constituting the high-voltage fixed resistor are formed on one insulating substrate, and trimming is performed in this state, so that the trimming operation can be performed easily and with high accuracy. Further, since it is not necessary to increase the number of work steps after connecting the respective fixed resistors of the first to n-th insulating substrates with the connection conductors, the possibility of occurrence of connection failure during the work steps is reduced.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1A to 1E are process diagrams for explaining an embodiment of the manufacturing method of the present invention. In this embodiment,
This is an embodiment in the case of manufacturing a high-voltage fixed resistor having a structure in which two insulating substrates are connected by a connection conductor according to the present invention.
First, a printed resistor substrate 12 is manufactured by printing a first fixed resistor R1 including a trimming resistor Rt and a second fixed resistor R2 in a predetermined pattern on a single insulating substrate 11 made of ceramic. At the center of the insulating substrate 11, a groove is formed in advance along a division line L to facilitate later substrate division. This groove may be a V-shaped groove having a cross section that opens toward one side of the insulating substrate 11, or may include two V-shaped grooves that open toward both sides of the insulating substrate 11. it can. Terminal electrodes T1 are connected to both ends of the fixed resistor R1 and one end of the trimming resistor Rt, respectively.
To T3 are formed. Terminal electrodes T4 and T5 are also formed at both ends of the fixed resistor R2. The terminal electrodes T3 and T4 located on both sides of the dividing line L are electrically connected by the conductor C. The terminal electrodes T1 to T5 and the conductor C can be simultaneously formed by printing a solderable conductive paint such as a silver paint. It is needless to say that the terminal electrodes T1 to T5 may be formed by fixing the conductive metal terminal to the insulating substrate 11 by an appropriate fixing method.

Next, as shown in FIG. 1B, trimming is performed on the trimming resistor Rt by using a known trimming technique using a laser beam or the like. Next, in this example, Rt
Trimming is performed to obtain a partial pressure ratio of / [(R1−Rt) + R2]. Then, as shown in FIG. 1C, the insulating substrate 11 is divided into two first insulating substrates 13 along the dividing line L.
And a second insulating substrate 14. This division can be performed using a known cutting technique such as a laser cutter.

Next, the terminal electrode T3 on the first insulating substrate 13
And the terminal electrode T4 of the second insulating substrate 14
Connect with The connection conductor 15 is connected to the terminal electrodes T3 and T
4 is connected by soldering. Before or after this soldering, the lead wires 16 are soldered to the terminal electrodes T1, T2 and T5, respectively. Of course, the soldering of the lead wires 16 may be performed before the insulating substrate 11 is divided.

After the soldering is completed, as shown in FIG. 1 (E), the entire surface is insulated and coated with an insulating resin material such as epoxy resin so as to leave the end of the lead wire 16 to form an insulating coating layer 17. Then, the production is completed.

The method of the present invention is not limited to the above embodiment. The number of insulating substrates constituting the high-voltage variable resistor is arbitrary, and may be appropriately increased or decreased according to the applied voltage. . FIG. 2 shows a process diagram of an embodiment of the method of the present invention in the case of manufacturing a high-voltage fixed resistor having a structure in which three insulating substrates 18 to 20 are connected by the connection conductor 15. In the embodiment of FIG. 2, the same parts as those of the embodiment of FIG. 1 are denoted by the same reference numerals as those of FIG. As in this embodiment, the trimming resistor Rt may be provided on the fixed resistor formed on the central insulating substrate 19 as a matter of course.

In each of the above embodiments, the present invention is applied to the case of manufacturing a high-voltage variable resistor capable of obtaining a division ratio. However, a general high-voltage variable resistor which does not obtain a division ratio is manufactured. In this case, the present invention can be applied.

[0014]

According to the present invention, all the fixed resistors constituting the fixed resistor for high voltage are first formed on one insulating substrate, and the trimming is performed in that state. Has the advantage that it can be performed easily and with high accuracy.
Further, according to the present invention, it is not necessary to increase the number of work steps after connecting the respective fixed resistors of the plurality of insulating substrates with the connection conductors, so that the possibility of poor connection of the connection conductors during the work steps is reduced. Become.

[Brief description of the drawings]

FIGS. 1A to 1E are process diagrams for explaining an embodiment of the method of the present invention.

2 (A) to 2 (E) are process diagrams for explaining another embodiment of the method of the present invention.

FIGS. 3A to 3D are process diagrams for explaining a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,11 Insulating substrate 2,12 Printed resistor substrate 3,16 Lead wire 4,17 Insulating coating layer 13 First insulating substrate 14 Second insulating substrate 15 Connection conductor Rt Trimming resistor R1 First resistor R2 Second Resistor T1 to T5 terminal electrode

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01C 13/00, 17/06, 17/22 H01C 17/24

Claims (1)

(57) [Claims] 1. A method for manufacturing a high-voltage fixed resistor comprising a fixed resistor including a trimming resistor printed on a surface of an insulating substrate, comprising at least the trimming resistor on a single insulating substrate. Preparing a printed resistor substrate formed by printing in a state where the first fixed resistor and the second to n-th fixed resistors are electrically connected; and trimming the first fixed resistor. After trimming the resistor, the printed resistor substrate is divided into first to n-th insulating substrates each having the first to n-th fixed resistors, and thereafter, the first insulating substrate to the n-th A method for manufacturing a high-voltage fixed resistor, wherein the first to n-th fixed resistors formed on an insulating substrate are electrically connected in series via connection conductors.