JP2545077Y2 - Chip type resistor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type resistor in which at least one electrode can be connected to a substrate conductor pattern by wire bonding or the like.

[0002]

2. Description of the Related Art In response to recent demands for miniaturization and weight reduction, electric components used have been miniaturized. Especially resistors etc.
For further miniaturization and weight reduction, many chip-type resistors have been used. FIG. 5 shows this conventional chip-type resistor, and FIG. 6 shows a state where such a resistor is mounted on a substrate. 5A is a plan view and FIG. 5B is a side sectional view.

In a conventional chip resistor, as shown in FIG. 5, for example, end electrodes 5 are provided on both side surfaces of an alumina substrate 1, and upper and lower electrodes 2 are provided on upper and lower surfaces near both side surfaces of the alumina substrate 1, for example. A resistive film 3 is formed between the upper and lower electrodes 2 on one surface of the alumina substrate 1 on which the electrodes 2 and 5 are disposed, and an insulating film 4 such as glass or plastic resin is formed so as to substantially cover the resistive film 3. Was formed. And
The vicinity of both ends of the upper and lower electrodes 2 is not covered with the insulating film 4 and the electrode portion 2 is exposed.

FIG. 6 shows a state in which the conventional chip type resistor shown in FIG. 5 is mounted on a substrate. In FIG. 6, 10 is P
The CB boards 11 are, for example, copper conductor wiring patterns provided on the PCB board 10, and a conventional chip-type resistor is fixedly mounted between the wiring patterns 11 with solder 12.

[0005]

[Problems to be Solved by the Invention] However, since chip-type resistors are small in size, it is almost impossible for a person to individually mount them after mounting other electrical components on the board. It is impossible to cope with a case where there is a difference in a conductor pattern to which a resistor is to be connected due to adjustment or the like.

[0006]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and has the following arrangement as one means for solving the above-mentioned problems. That is, a chip resistor that can be mounted on a substrate, wherein a first electrode portion having an electrode formed at an end on the upper surface from one side surface of the chip and an upper surface from a side opposite to the first electrode portion on the chip. A second electrode portion having an electrode formed at an end of the first electrode portion, and a resistive layer formed between an upper electrode of the first electrode portion and an upper electrode of the second electrode; The portion further includes a lower electrode extending from the one side electrode to the lower surface, and the second electrode portion further extends from the upper electrode by an area connectable to the upper portion of the resistance layer by wire bonding or the like. Is formed.

[0007] For example, the lower electrode and the upper electrode of the first and second electrode portions are characterized in that they make up about 60% of the chip surface area.

[0008]

In the above configuration, the upper electrode for bonding is formed on the main plane side on which the resistive film is formed, and the lower electrode is securely fixed to the conductor pattern disposed on the printed circuit board, thereby improving the printed circuit board. It is possible to select a conductor pattern to which the resistor is to be connected after the resistor is mounted on the substrate, and it is possible to improve the production efficiency by minimizing the bonding head drop. In addition, since the area of the lower electrode and the upper electrode can be increased at the same time, the heat dissipation is improved, and the rise in the surface temperature of the resistor can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings. 1 to 4 are views for explaining an embodiment according to the present invention, FIG. 1 is a diagram showing a configuration of an embodiment according to the present invention, and FIG. 2 is a mounting of the embodiment on a substrate. FIG. 3 is a plan view showing the state, FIG. 3 is a diagram for explaining the degree of freedom in selecting the wiring direction of the present embodiment, and FIG. 4 is a diagram showing the heat diffusion effect of the present embodiment.

First, the structure of this embodiment will be described with reference to FIG. FIG. 1A is a plan view of this embodiment, and FIG. 1B is a side sectional view. In FIG. 1, the same components as those in FIG. 5 described above are denoted by the same reference numerals, and detailed description is omitted. In the present embodiment shown in FIG. 1, the upper and lower electrodes 2 are arranged on both sides of the alumina substrate 1 near both ends of the alumina substrate 1 from the electrodes 5 at both ends of the conventional chip resistor shown in FIG. Instead, on the surface of the alumina substrate 1 where the resistive film 3 is formed on the upper surface of the drawing, upper surface electrode portions 8 and 9 substantially similar to the upper and lower electrodes 2 of the conventional resistor shown in FIG. 5 are formed. And the alumina substrate 1
The lower electrode 6 having a large area extending from the end electrode 5 on the surface on which one upper electrode 8 is formed is formed. Each of these electrodes can be formed by a method generally used conventionally, for example, a method such as printing / etching.

The upper electrodes 8 and 9 of the alumina substrate 1
A resistive film 3 is formed therebetween, and an insulating film 4 such as glass or plastic resin is formed so as to substantially cover the resistive film 3. At this time, at least the vicinity of the end of the upper electrode 9 where the lower electrode 6 is not formed is not covered with the insulating film 4 so that the electrode portion is exposed. Subsequently, the lower electrode 6 extends over the insulating film 4 from the end exposed electrode portion of the upper electrode 9 where the lower electrode of the resistor having the resistive film 3 and the insulating film 4 is not formed. A bonding electrode 7 having substantially the same area as that described above is formed.

The bonding electrode 7 may be fixed to the upper electrode 9 by any method as long as the bonding electrode 7 can be fixed so as not to be easily separated. For example, a method of activating a portion to be a bonding electrode with palladium (Pb) or the like and plating and fixing electroless nickel (Ni) or the like on the portion is a method using an electroless plating method. Alternatively, gold (Au), nickel (Ni), or the like is sputtered or vapor-deposited on a portion to be a bonding electrode, and the other portion is subjected to masking or the like to perform spattering (deposition) so as not to form a film. Further, when the insulating film 4 is made of glass, an arbitrary method such as a method of printing and firing an electrode paste on a portion to be a bonding electrode and fixing the same can be adopted. The lower electrode 6 and the bonding electrode 7 formed as described above have a chip type resistor having an outer shape of 1.25 mm to 2.5 mm in length and 2.0 mm to 5.0 mm in width.
mm, which is approximately 60% of the outer shape.
What is necessary is just to form it. The electrodes 8 and 9 only need to have an area that allows the lower electrode 6 to be securely fixed to the mounting substrate, and need only have an area that allows bonding. The electrode area is not limited to the above example.

FIG. 2 shows a state in which the chip type resistor of the present embodiment having the above configuration is mounted on a mounting board. In FIG. 2, reference numeral 20 denotes a PCB substrate, and reference numerals 22 and 22 denote, for example, copper conductor wiring patterns provided on the PCB substrate 20. In the chip-type resistor of this embodiment, the lower electrode 6 is fixed to one of the wiring patterns 21 and 22 on the PCB substrate 20.
Is performed by soldering or a conductive adhesive as shown by 23 in FIG. Then, for electrical connection with the other wiring pattern 21, the bonding electrode 7 and the wiring pattern 21 are connected by a conductive wire. For example, the bonding wire 25
Is used to connect the bonding electrode 7 and the wiring pattern 21 by bonding.

The chip-type resistor of this embodiment can not only connect two wiring patterns, but also, after mounting the resistor on the substrate, appropriately select a wiring pattern to be connected and connect it to a desired wiring pattern. Can be. Therefore, for example, as shown in FIG. 3, the wiring pattern of the PCB substrate is distributed in four directions as shown at 31 to 34, and the lower electrode 6 of the chip type resistor 30 of this embodiment is electrically connected to the wiring pattern 31. Is fixed with solder or a conductive adhesive so as to be in a connected state. Then, it is only necessary to determine which of the wiring patterns 32 to 34 is to be connected in consideration of other factors, and to connect the desired wiring pattern to the bonding electrode 7.

For example, when the resistor of this embodiment is used in an oscillation circuit, the frequency to be oscillated can be determined by the wiring pattern to be connected. Similarly, when the resistor of the present embodiment is used as a threshold value determining element of an amplifier circuit or a comparison circuit, a desired wiring pattern is selected according to the threshold value of the circuit and connected to the bonding electrode 7 by bonding or the like. do it.

In the resistor of this embodiment, since both the lower electrode 6 and the bonding electrode 7 have a large area,
The heat dissipation performance is also improved. FIG. 5 shows a resistor according to the present embodiment in which a resistor having a rated power of 0.5 W is used.
Fig. 4 shows the difference in heat dissipation characteristics from the conventional resistor shown in Fig. 4.
Shown in As shown in FIG. 4, the heat dissipation performance of the resistor according to the present embodiment is improved.

As described above, according to the present embodiment, the wiring direction on the printed circuit board can be freely selected, and even after the resistor is mounted on the board, one of the conductor patterns to which the resistor is to be connected can be used. You can choose. At the same time, by increasing the area of the electrode portion, the heat dissipation performance is improved, and the rise in the surface temperature of the resistor can be reduced.

[0018]

As described above, according to the present invention, the upper electrode for bonding is formed on the main plane side on which the resistive film is formed, and the lower electrode is securely connected to the conductor pattern provided on the printed circuit board. By fixing the wiring to the printed circuit board, the wiring direction to the printed circuit board can be freely selected, the conductor pattern to which the resistor should be connected after the resistor is mounted on the board can be selected, and the bonding head is reduced to reduce the production efficiency. Can be improved. In addition, since the area of the lower electrode and the upper electrode can be increased at the same time, heat dissipation is improved, and a rise in the surface temperature of the resistor can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment according to the present invention.

FIG. 2 is a plan view showing a mounting state of the present embodiment on a substrate.

FIG. 3 is a diagram for explaining a degree of freedom in selecting a wiring direction according to the embodiment;

FIG. 4 is a diagram showing a heat diffusion effect of the present embodiment.

FIG. 5 is a diagram showing a configuration of a conventional chip resistor.

FIG. 6 is a plan view showing a state in which a conventional resistor is mounted on a substrate.

[Explanation of symbols]

1 Alumina substrate 2 Upper and lower electrodes 3 Resistive film 4 Insulating film 5 End face electrode 6 Lower electrode 7 Bonding electrode 8,9 Upper electrode 10,20 PCB substrate 11,12,21,22,31-34 Wiring pattern.

Claims (2)

(57) [Scope of request for utility model registration] 1. A chip resistor mountable on a substrate, comprising: a first electrode portion having an electrode formed at an end of an upper surface from one side surface of the chip; and opposing the first electrode portion of the chip. A second electrode portion having an electrode formed at an end portion of the upper surface from the side surface; and a resistive layer formed between the upper electrode of the first electrode portion and the upper electrode of the second electrode. The first electrode portion further has a lower electrode extending from the one side electrode to the lower surface, and the second electrode portion further extends from the upper electrode by an area connectable to the upper portion of the resistance layer by wire bonding or the like. A chip-type resistor having an upper electrode formed thereon. 2. The chip-type resistor according to claim 1, wherein the lower electrode and the upper electrode of said first and second electrode portions make up about 60% of the chip surface area.