JP2003188002A - Resistor and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resistor provided with a resistance element whose cross- sectional shape is uniform. <P>SOLUTION: The entire region of a resistance element 16a of the resistor directly contacts a ceramics substrate 15a, with a front surface electrode 17a provided to the surface of the resistance element 16a. The front surface electrode 17a is electrically connected to a rear side electrode 18 by a sputter layer 21. On the resistance element 16a, protective layers 19 and 20 are provided to protect the resistance element. Since the entire region of the resistance element directly contacts the ceramics substrate, on which the front surface electrode is provided, the cross-sectional shape of the resistance element is uniform and a stable resistor is acquired. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resistor and a method for manufacturing the resistor.

[0002]

2. Description of the Related Art As shown in FIGS. 5 and 8, a resistor, for example, a chip resistor has a matrix slit 9 or 1 for division in advance.
The large-sized ceramic substrate 1 on which 0 is applied is divided into predetermined small pieces, and the front and back surfaces 2 and 3 are composed of Ag or Ag-Pd-based conductor paste on both the front and back edges in the longitudinal direction. The conductive film is formed by printing, drying, and baking, and further, the resistors 4 are independently formed so as to overlap and straddle the surface of one region inside the surface electrodes 2 and 2.

Then, a first protective film 5 is formed on the upper layer of the resistor 4 and trimmed by a laser so as to have a predetermined resistance value, and finished to a predetermined resistance value.
After the second protective film 6 is formed so as to cover the trimming groove portion, the rod-shaped substrate is manufactured by performing the primary division along the slits 9 for dividing the large-sized ceramic substrate in the row direction.

Then, a conductive film 7 is formed on the side surface of the rod-shaped substrate by a sputtering method to connect the front surface electrode 2 and the back surface electrode 3 to each other. Further, a second division is applied to the smallest unit piece along the dividing slit 10, and a plating film 8 is applied to the electrode portion including the side surface by Ni-Sn plating.

On the other hand, the shape of the chip resistor is such that by taking advantage of its light, thin, short, and small properties, the final product, for example,
It plays a role in saving energy and space by reducing the size and weight of home appliances and industrial equipment. As such miniaturization progresses, it is required to maintain the reproducibility of fine print patterns. Particularly, the stable formation of the resistor 4, which plays the essential role of the chip resistor, requires special attention.

As the chip resistors have become smaller in size in this way, the printed pattern size of the resistors naturally becomes smaller, so that the printing positions of the electrodes are aligned with the electrode terminals at both edges, and the resistance printed pattern and the surface electrodes are stretched by the screen. The position shift at will be accelerated. Further, in the conventional separated and independent resistor printing pattern, it is required to secure a predetermined electrode width in a portion overlapping with both surface electrodes while considering the flow-out of the resistance paste.

Therefore, the printing position is adjusted so that the maximum film thickness of the resistor is arranged in the central portion between both surface electrodes. Then, the resistor has a roughly "kamaboko" shape with left and right symmetry centered on the center between both surface electrodes, the cross-sectional shape of the resistor between both surface electrodes is not uniform, and the center is large. It becomes smaller toward the edges. Furthermore, since the surface electrodes are already formed on the ceramic substrate during resistance printing, fine pitch irregularities are present during resistance printing, and the smaller the resistance, the more impeding printing.

Further, as shown in FIG. 5, the surface of the large-sized ceramic substrate 1 is provided with surface electrodes 2 and 2 which have already been printed and fired before printing the resistors, so that irregularities of 30 μm to 10 μm are densely spaced at equal intervals. Has occurred in. When a resistor is printed on the ceramic substrate 1 as described above, the screen is squeezed to 30 μm to 1 μm by the surface electrode 2.
It is required to repeatedly follow the resistor printed portion 4a, which is the base of the resistor, on which the resistor is originally arranged, while crossing the 0 μm mountain.

On the other hand, as shown in FIG. 6, the printing pattern of the resistors independently separated and formed on the screen causes the screen 13 attached to the frame 12 to be pressed by the squeegee 11 against the ceramic substrate 1. The actual resistance printing pattern 14a different from the originally expected resistance printing pattern 14 appears by extending like the screen 13a with respect to the operation direction 11a of the squeegee 11.

Further, as shown in FIG. 7, the squeegee 11
The screen 13 extends like the screen 13a also in the direction perpendicular to the operation direction 11a (FIG. 6), and an actual resistance printing pattern 14b different from the originally expected resistance printing pattern 14 appears.

As a result, as shown in FIG. 4, the extended actual resistance printing patterns 14c are printed on the expected resistance pattern 14. The amount of displacement of such a print pattern depends on the amount 15 of off-contact with the medium of the screen (FIG. 6), etc., but as other factors, the cumulative number of times of use of the screen itself and deterioration of tension of the cloth due to handling are appropriately added. Therefore, it is difficult to control in advance.

[0012]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a resistor and a method for producing the resistor in which the cross-sectional shape of the printed pattern of the resistor is uniform and stable.

[0013]

According to the present invention, a resistor is formed in a strip shape so as to be in direct contact with the surface of a flat ceramic substrate having no unevenness, and a conductor layer is formed from the resistor to serve as a surface electrode. By forming the resistor on the surface layer of the resistor, it is possible to obtain a resistor having a stable resistor having a uniform cross-sectional shape.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A method of manufacturing a resistor of the present invention, here, a chip resistor will be described with reference to the manufacturing flow of FIGS. As shown in FIG. 2, in the chip resistor, a strip-shaped resistor 16 is printed and dried (S1) between the slits 10 on one side of the large-sized ceramic substrate 15 provided with the dividing matrix slits 9 and 10. Sinter the resistor (S
2) Do. Next, the back surface electrode is printed and dried (S3), the conductor layer 17 serving as the front surface electrode is printed and dried (S4) so as to straddle the resistor, and these electrodes are fired (S5).

Next, a first protective film (not shown) is printed on the surface of the resistor along the other slit 9 and dried (S).
6) Then, the protective film is baked (S7). Next, the resistor is laser-trimmed to trim the resistance value to a desired value (S8). Next, the second protective film is printed and dried on the resistor along the other split slit 9 (S9), and the protective film is baked (S10). Next, the substrate is first divided (S11) along one of the dividing slits 10, and the cross section of the rod-shaped substrate is sputtered (S12) to form a conductive film.

Next, the rod-shaped substrate is secondarily divided (S13) along the other division slit 9 into chips, and the electrodes are solder-plated (f14). The resistance value of the resistors divided into chips is measured and inspected (f15). Since the resistor has a strip shape in this manner, it is not necessary to consider the elongation of the screen due to squeegee, and a resistor having a uniform cross-sectional shape and a planar shape can be obtained. After that, the first protective film is formed by squeezing in a strip shape perpendicular to the strip-shaped longitudinal direction of the resistor, and like the resistor, the operation direction of the squeegee is selected in the same direction as the strip-shaped longitudinal direction. By doing so, it is not necessary to consider the elongation of the screen, and stable printing can be performed.

FIG. 1 shows a cross section of a chip resistor of the present invention manufactured based on the flow of manufacturing the chip resistor. As shown in FIG. 1, the chip resistor is provided with a resistor 16a obtained by dividing the strip-shaped resistor 16 on a ceramic substrate 15a.
The front surface electrode 17a is laminated on the upper surface of the
8 is formed.

Here, since there is no printed surface of the conductor layer 17 (FIG. 2) constituting the surface electrode 17a on the surface of the large-sized ceramic substrate when the strip-shaped resistor is printed, a smooth surface with no unevenness is formed. Since it can be printed, it is a stable resistor with a uniform cross-sectional shape. A first insulating protective film 19 is provided on the resistor 16a.

While the resistance value is being measured through the first insulating protective film 19, the second protective film 20 is formed by the first protective film 20 in order to block the trimming groove formed by laser trimming from the outside and prevent an external error from entering. The protective film 19 is laminated on the protective film 19. Further, a primary division is performed along the division slits in the column direction of the large-sized ceramic substrate, and a sputtering for electrically connecting the front surface electrode 17a and the rear surface electrode 18 formed by sputtering on the cross section of the rod-shaped substrate after the division. Membrane 2
1, and the plating film 22 is applied to the front and back electrodes including the side surface.

Although the embodiment described above is a chip resistor, it can be applied to, for example, a resistor array in which resistors are formed into a circuit and arranged appropriately.

[0021]

According to the present invention, a band-shaped resistor serving as a resistor of a resistor is first applied directly to a large-sized ceramic substrate so that printing defects such as those due to surface irregularities during printing may occur. It is possible to provide a chip resistor which has a uniform cross-sectional shape.

Further, since the resistor has a strip shape, unlike the conventional printing method in which each chip resistor is separated, fluctuations caused by complicated printing alignment with respect to electrodes, cumulative number of printed sheets, etc. Control of factors is significantly eased, mass productivity is high, and a stable resistor film is formed, so that a chip resistor having significant quality and performance can be provided. Therefore, the present invention exerts an excellent effect particularly for manufacturing a small chip resistor having a unit dimension in the longitudinal direction of 1 mm or less.

[Brief description of drawings]

FIG. 1 is a sectional view of a resistor according to the present invention.

FIG. 2 is a perspective view of a large-sized ceramic substrate on which a strip resistor and a surface electrode used for manufacturing the resistor of the present invention are printed.

FIG. 3 is a flow chart for making a resistor of the present invention.

FIG. 4 is an explanatory diagram for explaining printing deviation of a resistor by a conventional method for manufacturing a resistor.

FIG. 5 is a perspective view of a large-sized ceramic substrate used for manufacturing a conventional resistor.

FIG. 6 is an explanatory diagram illustrating a problem of squeegee printing a resistor.

FIG. 7 is an explanatory diagram illustrating a problem of squeegee printing a resistor.

FIG. 8 is a sectional view of a conventional resistor.

[Explanation of symbols]

15 ··· Ceramic substrate 16 · · Band-shaped resistor 17
..Conductor layer forming surface electrodes

Claims (6)

[Claims] 1. A resistor comprising a resistor formed on an insulating substrate, wherein the entire region of the resistor is in direct contact with the insulating substrate, and electrodes are provided on the surface of the resistor. Resistor. 2. The resistor according to claim 1, wherein a back surface electrode electrically connected to the electrode formed on the front surface is provided on the insulating substrate. 3. The resistor according to claim 1, wherein a protective layer for protecting the resistor is provided on the resistor. 4. A method for producing a resistor, comprising: forming a resistor on an insulating substrate; and a whole region of the resistor being in direct contact with the substrate; and forming electrodes on the surface of the resistor. , On a single insulating substrate with slits for division formed in a matrix,
A strip-shaped resistor is formed between the one split slit, and a conductor layer serving as an electrode of a chip resistor is formed across the strip-shaped resistor along the other split slit. How to make a resistor. 5. Each of the strip-shaped resistors formed on one insulating substrate is a film continuous in the longitudinal direction when the insulating substrate is divided into rod-shaped small pieces. The method for manufacturing a resistor according to claim 4. 6. The method of manufacturing a resistor according to claim 4, wherein a strip-shaped protective film is formed on the strip-shaped resistor in a direction perpendicular to the strip-shaped resistor.