JPH08203701A - Chip-type fixed resistor - Google Patents

Abstract

PURPOSE: To provide a chip-type fixed resistor, which has excellent surge voltage resistance that suppresses discharge between the electrodes and is to be used for the circuit of an automobile component, etc., whereupon the surge voltage is to be applied. CONSTITUTION: The facing corners 2a of one side of a pair of primary electrodes 2 are permitted to have roundness, the width of the primary electrode 2 is permitted to be narrower than the width of a resistor 3 so as to permit one of the facing sides to be thoroughly surrounded by the resistor 3. Thus, a chip-type fixed resistor, which does not easily discharge by the surge voltage applied between the initial electrodes, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type fixed resistor.

[0002]

2. Description of the Related Art FIG. 7 is a plan view of a conventional chip type fixed resistor, and FIG. 8 is a perspective view thereof. 1 in FIGS. 7 and 8
Is an insulating substrate. A pair of rectangular primary electrodes 2 are formed on both ends of one surface of the insulating substrate, and then a resistor 3 is formed so as to partially overlap the pair of primary electrodes. In the chip type fixed resistor, a primary electrode is printed and baked on one surface of an insulating substrate having a predetermined size in which a grid-shaped dividing groove is formed, a resistor is printed and baked, and then the dividing groove is formed. Laser trimming for adjusting the resistance value before printing, printing, baking, etc. of the protective glass 13 are performed before the division to expose the end face forming the end face electrode 14 by primary division. After the end face electrodes 14 are formed, a one-chip fixed resistor is obtained by secondary division, and the primary electrodes and end face electrodes are plated to complete the product.

[0003]

However, in the conventional chip type fixed resistor, when a surge voltage is applied to both ends of the chip type resistor, charge is applied to the tip of the corner of the primary electrode 2. It had a structure that could be concentrated and easily discharged. Therefore, when used in a power supply circuit for automobile parts or the like, there is a problem that discharge occurs between the electrodes and destroys active parts such as ICs connected to the chip resistors.

The present invention solves the above-mentioned problems of the prior art and provides an excellent chip-type fixed resistor for suppressing discharge between opposing electrodes of the primary electrode.

[0005]

In order to solve the above-mentioned conventional problems, the chip-type fixed resistor of the present invention eliminates the right-angled parts at both ends of the pair of primary electrodes facing each other, and further has an R shape. It was done. In addition, the width of the primary electrode is made smaller than the width of the resistor arranged so as to partially overlap the primary electrode, and the shape is formed so that the primary electrode overlaps only inside the resistor, and the opposing sides are all surrounded by the resistor. It has a structure.

[0006]

Originally, in the case of discharging between a pair of primary electrodes, electric charges are often concentrated at the tip of an acute-angled portion of the electrode shape with the shortest electrode interval, and the pair of primary electrodes is discharged. Since the right-angled portions at both ends of one side of the primary electrode facing each other are eliminated, electric charges are not concentrated and the discharge between the counter electrodes can be suppressed. Further, since the opposing sides of the primary electrode are surrounded by the resistor and the resistor functions as a protective film, it works to suppress the discharge from the opposing sides of the primary electrode, and it is difficult for the opposing electrodes to discharge. It is a structure.

[0007]

【Example】

(Embodiment 1) An embodiment of a chip type fixed resistor of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a chip type fixed resistor according to the present invention. In FIG. 1, 1 is an insulating substrate, 2 is a primary electrode, 2a is a corner of a primary electrode, and 3 is a resistor. is there.

A pair of primary electrodes 2 are printed and fired on both ends of one surface of the insulating substrate 1, and then a resistor 3 is printed and fired so as to overlap a part of the primary electrodes 2. The corners 2a on one side of the primary electrode 2 facing each other have an R shape in which a corner that is conventionally a right angle has a rounded arc. Therefore, even when a surge voltage is applied between the primary electrodes 2,
It has a structure in which electric charges are less likely to concentrate in one place, and discharge between electrodes can be suppressed.

FIG. 5 and FIG. 6 show a measurement circuit and a measurement result of an electrostatic breakdown test performed to clarify the improvement of the discharge start voltage when a surge voltage is applied due to the above electrode shape. The circuit shown in FIG. 5 has a power supply 4, a capacitor 5, and a switch 7, and the capacitor 5 and the sample 6 are connected in parallel. Here, the power source 4 is 2 to 10 [kV], and the capacitor 5 is about 10,000 [pF]. Using the measurement circuit shown in FIG. 5, a voltage was applied between the electrodes of the sample in which the distance between the opposing sides of the pair of primary electrodes 2 was changed 10 times at a period of 4 seconds (2 seconds on, 2 seconds off), 2k. The applied voltage is gradually increased from the volt at intervals of 0.5 kV,
This is a measurement of the discharge start voltage. Reference numeral 8 is a conventional electrode shape, and 9 is the electrode shape of this embodiment, and the effect of the electrode shape of this embodiment is shown. Here, the sample used for the measurement is not subjected to trimming or protective glass.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, the insulating substrate 1 and the resistor 3 are almost the same as those in the prior art. The difference from the configuration of the prior art is that the width of the primary electrode 2 is made narrower than the width of the resistor 3 arranged so as to overlap a part of the primary electrode 2.
This is a structure in which all the opposite sides of the primary electrode are surrounded by a resistor. With the above configuration, the resistor functions as a protective film, and the discharge start voltage can be lowered with respect to the discharge between the opposing electrodes of the primary electrode 2.

The discharge start voltage according to the electrode shape of this embodiment was measured under the same measurement circuit and conditions as in Embodiment 1, and the result is shown in FIG. It can be seen that the discharge start voltage due to the surge voltage is improved by adopting the configuration of this embodiment as compared with the conventional electrode shape.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, the corners of the primary electrode of the first embodiment are rounded.
It is not a shape but a C-plane. As shown in FIG. 3, the pair of primary electrodes has a shape in which the corners of one side facing each other are cut out by a straight line.

The discharge start voltage according to the electrode shape of this embodiment was measured under the same measurement circuit and conditions as in Embodiment 1, and the result is shown at 11 in FIG. From this graph, it can be seen that the discharge starting voltage is improved by the configuration of this example as compared with the conventional electrode shape.

(Embodiment 4) A fourth embodiment of the present invention will be described below with reference to the drawings.

This embodiment is a combination of the features of the shapes of the primary electrodes 2 of Embodiments 1 and 2. As shown in FIG. 4, the width of the primary electrode 2 is made narrower than the width of the resistor 3, and the corners of the pair of primary electrodes 2 facing each other are rounded to form an R shape. Is.

The result of measuring the discharge starting voltage according to the electrode shape of the present embodiment under the same measurement circuit and conditions as in Embodiment 1 is shown in FIG. The good results above the measurement results obtained by the electrode shapes of Example 1 and Example 2 are obtained, and it is understood that the shape is the most resistant to discharge when a surge voltage is applied between the electrodes.

[0020]

As described above, according to the present invention, the corners of one side of a pair of primary electrodes facing each other are taken and the R shape is formed so that the electric charge is not concentrated at one place, and the primary electrode By making the width narrow and covering all the opposite sides of the primary electrode, the resistor has a function as a protective film, so that it is difficult for discharge to occur when a surge voltage is applied between the electrodes. In other words, it is possible to provide a chip type fixed resistor that can be sufficiently used for automobile parts.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment which is an embodiment of a chip type fixed resistor of the present invention.

FIG. 2 is a plan view of the second embodiment.

FIG. 3 is a plan view of the third embodiment.

FIG. 4 is a plan view of the fourth embodiment.

[Fig. 5] Measurement circuit diagram of electrostatic breakdown test of chip type fixed resistor

FIG. 6 is a discharge start voltage diagram in an electrostatic breakdown test of a chip type fixed resistor.

FIG. 7 is a plan view of a conventional chip type fixed resistor.

FIG. 8 is a perspective view of the same.

[Explanation of symbols]

 1 Insulating Substrate 2 Primary Electrode 2a Corner of Primary Electrode 3 Resistor

Claims (3)

[Claims] 1. A chip-type fixed resistor having an insulating substrate, a pair of primary electrodes formed on the substrate, and a resistor overlapping a part of the pair of primary electrodes. A chip-type fixed resistor characterized in that the opposite corners of the primary electrode are rounded. 2. A chip type fixed resistor having an insulating substrate, a pair of primary electrodes formed on the substrate, and a resistor overlapping a part of the pair of primary electrodes. A chip-type fixed resistor characterized in that the width of the primary electrode is narrower than the width of the resistor, and the corners of the pair of primary electrodes are surrounded by the resistor. 3. The chip-type fixed resistor according to claim 2, wherein opposite corners of the pair of primary electrodes are rounded.