JPH10312917A - Manufacture of chip resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a resistor to be formed uniform in film thickness and furthermore resistors to be formed uniform in film thickness throughout a board by a method wherein resistor paste is applied onto an insulating board, electrode paste is applied around the ends of the applied resistor paste and dried out, and the resistor paste and the electrode paste are burned at the same time. SOLUTION: Resistor paste is applied onto the surface of a board 1 and dried up to serve as a resistor 2. Then, electrode paste is applied onto each end of the resistor 2 and dried up to serve as electrodes 3, and the resistor 2 and the electrodes 3 are burned at the same time. At this point, the resistor paste regulated in composition for application comprises ruthenium oxide, borosilicate lead glass, and organic vehicle as a main component, and the electrode paste contains silver oxide, lead oxide, borosilicate lead oxide, and organic vehicle. A burning process is carried out at temperatures of 800 to 900 deg.C for 30 to 60 minutes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for manufacturing a chip resistor.

[0002]

2. Description of the Related Art Conventionally, a chip resistor having a resistor and an electrode formed on an insulating substrate has been manufactured. FIG. 1 is a longitudinal sectional view showing an example of the structure of the chip resistor. In FIG. 1, reference numeral 1 denotes an insulating base made of ceramic or the like, 2 denotes a resistor formed on the surface thereof, and 3 denotes electrodes provided at both ends thereof. As a procedure for manufacturing a resistor, as a conventional example 1, first, an electrode paste serving as a base of the electrode 3 is applied to the surface of the insulating base 1 in FIG. The resistance paste is applied and dried, and the electrode and the resistor are fired simultaneously (simultaneous firing).

FIG. 2 is a longitudinal sectional view showing another example of the structure of the chip resistor. In the same figure, as in FIG.
Is an insulating base made of ceramic or the like, 2 is a resistor formed on the surface thereof, and 3 is electrodes provided on both ends thereof.
As a procedure for manufacturing the resistor, as a conventional example 2, first, a resistive paste that forms the basis of the resistor 2 is applied to the surface of the insulating base 1 shown in FIG. Is applied, dried and fired (individual firing).

Further, as a third conventional example, in FIG.
There is also a method in which an electrode paste that forms the basis of the electrode 3 is applied to the surface of the insulating base 1, dried and fired, and then a resistance paste that is the basis of the resistor 2 is applied, dried and fired ( Individual firing). In an actual manufacturing process, in each of the above examples, a large number of the configurations of any of the above examples are arranged on, for example, a ceramic substrate which is a base of the insulating base 1, and the chip resistor of each piece is diced by dicing. Be separated.

[0005]

However, in the case of the above-mentioned prior art example 1, since the resistance paste is applied while the electrode paste is dried and the film thickness is large, the resistance paste is affected by the variation in the film thickness of the dried electrode paste. The thickness of the resistor 2 is not uniform within one piece or even within one ceramic substrate.

In the case of Conventional Example 2, the resistance value of the resistor 2 after firing of the resistor paste cannot be measured accurately because the electrode 3 is not formed at that time. Therefore, it is not possible to manage the change in the resistance value during firing of the electrode paste. Therefore, it is difficult to continuously and accurately determine the resistance value.

In the case of the conventional example 3, the disadvantage of the conventional example 2 is not observed, and it is most convenient in the sense of determining the resistance value. As a result, the thickness of the resistor 2 does not become uniform within one piece and further within one ceramic substrate. Since the thickness of the resistor 2 cannot be determined, the TCR (temperature coeffici
ent of resistance, temperature coefficient of resistance, STOL (shor
t time over load, short time overload test) becomes unstable. This is the same in Conventional Example 1.

According to the present invention, by making the thickness of the resistor uniform within one piece or even within one substrate, and by determining the resistance value by one firing, there is little variation in resistance value and defects, and the resistance value is reduced. It is an object of the present invention to provide a method of manufacturing a chip resistor which can easily manage the resistance.

[0009]

In order to achieve the above object, according to the present invention, a resistive paste is applied on an insulating substrate and dried, and then an electrode paste is applied around both ends of the resistive paste and dried. Finally, a method for manufacturing a chip resistor is characterized in that a resistor and an electrode are formed on the insulating base by simultaneously firing the resistor paste and the electrode paste.

[0010] Further, a method of manufacturing a chip resistor is characterized in that the resistor paste and the electrode paste are simultaneously fired under the following firing conditions. Firing conditions: 800-900 ° C, 30-60 minutes

[0011]

Embodiments of the present invention will be described below. The structure of the chip resistor according to the manufacturing method of the present invention is as shown in FIG. The procedure for manufacturing the resistor is as follows. First, a resistive paste for forming the resistor 2 is applied to the surface of the insulating substrate 1 shown in FIG. Is applied and dried, and the electrode 3 and the resistor 2 are simultaneously fired (simultaneous firing).

Thus, the resistive paste is applied to the surface of the insulating substrate 1 in a state where there is nothing relating to the electrodes, so that a uniform resistor film thickness can be obtained without being affected by the change in the film thickness of the electrodes. In addition, since firing is performed only once, there is no need to control the change in resistance value due to electrode firing, and it is easy to judge fluctuations in firing conditions, and the resistance value can be controlled only by controlling the thickness of the resistor paste and the thickness of one firing. Can be determined. Hereinafter, the main components and firing conditions of the resistance paste and the electrode paste prepared for application in the present invention will be described.

[0013]

[0014]

Among the above-mentioned main components, the organic vehicle is a solvent for converting the material of the resistor or the electrode into a paste, and a solvent such as terpineol which usually contains a resin component is used. At the time of firing, these organic vehicles scatter, and the remainder becomes a resistor or an electrode, respectively. In addition, silver oxide, which is a main component of the electrode paste, may be mixed with gold, platinum, or the like as a substance to increase conductivity.

FIG. 3 is a graph showing the relationship between firing and resistance. As shown in the figure, when the resistance paste is dried, it does not function as a resistor yet, and the resistance value is infinite. At the time of the first firing, the resistance value is determined in Conventional Example 1 and the present invention, but in the case of Conventional Example 1, the resistance value has a large variation. Further, in the case of the conventional example 2, since no electrode is formed at this time, it is difficult to measure the resistance value, and the graph shows the estimated value by a broken line.

In Conventional Examples 2 and 3, the second firing is further performed, and the resistance value has changed from the first firing, respectively. Further, in the third conventional example, since the influence of the film thickness of the electrode is exerted as described above, the variation in the resistance value is larger than in the second conventional example. As a result, the variation in the resistance value is as follows: Conventional example 1> Conventional example 3> Conventional example 2 = the present invention in the descending order, and the present invention is the most excellent method in which the resistance value is small and the resistance value can be determined by one firing. It turns out that it is.

Further, in Conventional Examples 1 and 3,
Since the thickness of the resistor in one piece is not uniform due to the influence of the electrodes, when adjusting the resistance value by laser trimming, the resistance value depends on the trimming position as shown in FIG. That is, when the trimming groove 4 is formed at the end of the resistor 2 as shown in FIG.
When the trimming groove 4 is formed near the center of the resistor 2 as shown in FIG. 3B, the resistor is thin, and the trimming is sufficient.

On the other hand, in the present invention, as shown in FIG. 5, since the film thickness of the resistor 2 is uniform, the trimming can be performed satisfactorily regardless of the trimmed portion. Uniform laser trimming can be performed without being affected.

[0020]

As described above, according to the present invention,
By making the thickness of the resistor uniform within one piece or even one substrate, and by determining the resistance value by one firing, there is little variation and failure of the resistance value, and it is easy to manage the resistance value. It can provide a method of manufacturing a vessel. Furthermore, since the thickness of the resistor is uniform, the trimming can be performed satisfactorily regardless of the trimming of any part. Therefore, a method of manufacturing a chip resistor capable of performing uniform laser trimming regardless of the trimming position is described. Can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of the structure of a chip resistor.

FIG. 2 is a longitudinal sectional view showing another example of the structure of the chip resistor.

FIG. 3 is a graph showing a relationship between baking and a resistance value.

FIG. 4 is a longitudinal sectional view showing a state of laser trimming in a conventional example.

FIG. 5 is a longitudinal sectional view illustrating a state of laser trimming in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating base 2 Resistor 3 Electrode 4 Trimming groove

Claims (2)

[Claims] 1. A method of applying a resistive paste on an insulating substrate, drying the resistive paste, applying an electrode paste around both ends of the resistive paste, drying the resistive paste, and finally firing the resistive paste and the electrode paste simultaneously. Forming a resistor and an electrode on the insulating substrate. 2. The method according to claim 1, wherein the resistor paste and the electrode paste are simultaneously fired under the following firing conditions. Firing conditions: 800-900 ° C, 30-60 minutes