CN103201801B - Manufacturing method of metal plate low resistance chip resistor - Google Patents

Abstract

The invention provides a method for manufacturing a metal plate low-resistance chip resistor, which can easily form a protective film without being influenced by the width of a resistance metal plate of a long strip-shaped part, and can adjust the width of the protective film according to the thickness unevenness of the resistance metal plate in the width direction, thereby expanding the freedom degree of adjusting the width of the protective film. Therefore, a protective film forming step of forming a protective film on the front and back surfaces of the resistive metal plate is performed (step S13), and then a slit forming step of forming slits in the resistive metal plate and forming the resistive metal plate to have a long-shaped portion and a connecting portion is performed (step S14). The method includes the steps of performing a resistor metal plate thickness measuring step (step S12) of measuring the thickness of each position in the width direction of the resistor metal plate for forming the protective film before the protective film forming step (step S13), and setting the width of the protective film based on the measured thickness of each position in the width direction of the resistor metal plate in the protective film forming step (step S13).

Description

Manufacturing method of metal plate low resistance chip resistor

technical field

The present invention relates to a method of manufacturing a chip resistor using a resistive metal plate.

Background technique

In various control circuits such as power supply units and rotational speed control circuits of motors, means for detecting current is required. There are many ways to sense the current, but most of them use electronic components such as shunt resistors. A chip resistor is known as a resistor suitable for such a shunt resistor or the like. In addition, among the above-mentioned chip resistors, a resistive metal plate is mainly used in the manufacture of a chip resistor having a very low resistance value of several mΩ. A low-resistance chip resistor manufactured using the above-mentioned resistance metal plate is generally called a metal plate low-resistance chip resistor.

As shown in FIGS. 16( a ) to 16 ( c ), the metal plate low-resistance chip resistor 1 has a cuboid appearance and is manufactured using a resistance metal plate 2 . Protective films 3a, 3b are formed on the front surface 2a and the back surface 2b of the resistance metal plate 2, respectively. The protective films 3a and 3b are electrically insulating films. In addition, the surfaces of both ends 2e and 2f in the longitudinal direction of the resistance metal plate 2 (the left-right direction of FIG. 16(b) and FIG. 16(c)) on which the protective films 3a and 3b are not formed (that is, the surfaces of the surface 2a Electrode plating films 4a, 4b are formed on the widthwise ends 2a-1, 2a-2, the widthwise end portions 2b-1, 2b-2, and the end faces 2c, 2d) of the rear surface 2b.

Regarding the dimensions (unit: mm) of the chip resistor 1, for example, the total length L1 of the chip resistor 1 is specified as 1.6±0.1 (tolerance), and the length C of the electrode plating films 4a and 4b is 0.2±0.1 (tolerance), The width W of the chip resistor 1 is 0.8±0.1 (tolerance), and the thickness H of the chip resistor 1 is 0.3±0.1 (tolerance). Each dimension of the above-mentioned chip resistor 1 including tolerances is set in accordance with dimensional constraints and the like when the chip resistor 1 is mounted on a circuit board. The length L2 of the protective films 3a and 3b is the difference (L1-2×C) between the total length L1 of the chip resistor 1 and the length (full length) 2×C of the electrode plating films 4a and 4b on both sides. In other words, L2 is the length of the portion of the resistance metal plate 2 covered with the protective films 3a, 3b. In addition, the thickness of the resistance metal plate 2 is thickness T, and the length of the resistance metal plate 2 is length L3.

Conventionally, by sequentially implementing the band-shaped resistance metal plate cutting process (step S1), the slit forming process (step S2), the protective film forming process (step S3), and the electrode plating film forming process (step S3) shown in the process flow chart of FIG. S4), the strip-shaped portion cutting process (step S5) and the strip-shaped portion cutting process (step S6), to manufacture the metal plate low-resistance chip resistor 1 with the structure shown in FIG. 16 .

The slit forming step (step S2 ) and the protective film forming step (step S3 ) will be further described with reference to FIGS. 18 and 19 . In addition, for the strip-shaped resistance metal plate cutting process (step S1), the electrode plating film forming process (step S4), the strip-shaped portion cutting process (step S5) and the strip-shaped portion cutting process (step S6), the same as that shown in FIG. The strip-shaped resistance metal plate cutting process (step S11), the electrode plating film forming process (step S15), the strip-shaped portion cutting process (step S16), and the strip-shaped portion cutting process (step S17) shown are the same, and the details of these processes See below for the content.

As shown in Fig. 18(a) to Fig. 18(c), in the slit forming step (step S2), a plurality of (five in the figure in the example) slits 6 are formed on the rectangular resistance metal plate 2B. . In the strip-shaped resistance metal plate cutting step (step S1 ), the resistance metal plate 2B is cut out from the strip-shaped resistance metal plate 2A (see FIG. 2 ). The slits 6 extend in the longitudinal direction of the resistance metal plate 2B (the vertical direction in FIG. 18( b )) and are parallel to each other in the width direction of the resistance metal plate 2B (the horizontal direction in FIG. 18( b )). In addition, the position where the slit 6 is formed is set with reference to the positioning mark 5 . By forming the plurality of slits 6, the shape of the resistance metal plate 2B becomes a shape having a plurality (four in the figure) of elongated portions 7 and connecting portions 8. The plate 2B extends in the longitudinal direction, and the connecting portions 8 connect both ends of the plurality of elongated portions 7 in the longitudinal direction (the vertical direction in FIG. 18( b )).

As shown in FIGS. 19( a ) to 19 ( c ), in the subsequent protective film forming step (step S3 ), screen printing or the like is applied to each elongated portion 7 on the resistive metal plate 2B. A plurality of protective films 3A, 3B are formed on the front surface 2B-1 and the back surface 2B-2 of the protective film 2B-2 respectively. The protective films 3A and 3B extend in the longitudinal direction of the resistance metal plate 2B and are parallel to each other in the width direction of the resistance metal plate 2B. In addition, the positions where the protective films 3A and 3B are formed are set with reference to the positioning marks 5 .

In addition, as prior art documents disclosing a manufacturing method of a chip resistor, there are, for example, the following patent documents 1 and 2.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open Publication No. 2009-218552

Patent Document 2: International Publication No. 2008/018219 Booklet

Contents of the invention

The technical problem to be solved in the present invention

In the conventional manufacturing method of the metal plate low-resistance chip resistor, the slits 6 are formed before the protective films 3A and 3B are formed. That is, after the elongated portion 7 is formed by forming the slit 6 in the resistance metal plate 2B, the protective films 3A, 3B are formed on the elongated portion 7 . Therefore, the above-described conventional method of manufacturing a metal plate low-resistance chip resistor has the following problems.

That is, when the slits 6 are formed prior to the protective films 3A, 3B, the protective films 3A, 3B must be formed on the front 2B-1 and back 2B-2 of the resistance metal plate 2B whose elongated portion 7 is very narrow. Therefore, formation of the protective films 3A, 3B is difficult. In addition, when further miniaturization of the chip resistor 1 is required, since the width of the resistance metal plate 2B of the elongated portion 7 is narrower, it is more difficult to form the protective films 3A and 3B. In addition, when forming the protective films 3A and 3B, the paste is generally patterned by a screen printing method, and further, a photolithography method is used to improve the dimensional accuracy. Furthermore, when the photolithography method is used, if the slit 6 is first formed prior to the protective films 3A, 3B, the manufacturing method will become complicated.

Moreover, in order to form the strip-shaped resistance metal plate 2A (refer FIG. 2) used for manufacturing the chip resistor 1 into desired thickness, it manufactures by repeating an annealing process and a rolling process. However, the thickness of the strip-shaped resistance metal plate 2A is not completely uniform, and in particular, thickness unevenness occurs in the width direction of the resistance metal plate 2A. Therefore, in the resistance metal plate 2B cut out from the strip-shaped resistance metal plate 2A, thickness unevenness also occurs in the width direction.

In addition, the uneven thickness in the width direction of the resistance metal plate 2B causes unevenness in the resistance value of the chip resistor 1 . On the other hand, the resistance value of the chip resistor 1 is determined by the width W, length L2, and thickness T (see FIG. 16 ) of the portion covered by the protective films 3 a and 3 b of the resistive metal plate 2 . That is, it is determined by formula (1) and formula (3) mentioned later. Therefore, in the manufacturing process of the chip resistor 1, according to the thickness unevenness in the width direction of the resistance metal plate 2B, it is necessary to adjust the widths L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ , to reduce the unevenness of the resistance value of the chip resistor 1 . In addition, at this time, the allowable range of adjustment related to the width L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ of the protective film 3A, 3B (that is, the length L2 of the protective film 3a, 3b of the chip resistor 1 ) is preferably as large as possible.

In contrast, as shown in FIG. 20 , in the case of the dimensional example of the chip resistor 1 described above, the allowable range of adjustment of the length L2 of the protective films 3 a and 3 b in the conventional manufacturing method is 0.4 mm. That is, since the slit 6 is formed prior to the protective films 3A and 3B, the length L3 of the resistance metal plate 2 is determined prior to the length L2 of the protective films 3a and 3b in the chip resistor 1, and the overall length of the chip resistor 1 is determined. L1. For example, assuming that the total length L1 of the chip resistor 1 is 1.6mm, the maximum length 2×C of the electrode plating films 4a, 4b is 0.6mm (=2×(0.2+0.1)) and the shortest is 0.2mm (= In the case of 2×(0.2-0.1)), the lengths L2 of the protective films 3 a and 3 b are 0.9 mm and 1.3 mm, respectively. Therefore, the allowable range of adjustment of the length L2 of the protective films 3 a and 3 b is 0.4 mm (=1.3-0.9). When the overall length L1 of the chip resistor 1 is set to 1.5 mm (=1.6-0.1) and 1.7 mm (=1.6+0.1), the allowable adjustment range is also the same.

In addition, as a method of reducing the variation in the resistance value of the chip resistor due to the variation in the thickness of the resistance metal plate in the width direction, there is a method of adjusting the resistance value by trimming the resistance metal plate. However, after the resistance metal plate is trimmed, when a chip resistor using the trimmed resistance metal plate is connected to a load and current flows through the chip resistor, hot spots are generated on the chip resistor, so There is a problem that load characteristics such as life characteristics of chip resistors deteriorate. Therefore, in order to reduce the unevenness in the resistance value of the chip resistor 1 caused by the uneven thickness of the resistance metal plate 2B in the width direction, it is necessary to adjust the thickness of the protective films 3A and 3B instead of trimming the resistance metal plate 2B. The method of width L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ is implemented.

Therefore, in view of the above problems, an object of the present invention is to provide a method for manufacturing a metal plate low-resistance chip resistor, which can easily form a protective film without being affected by the width of the resistance metal plate in the elongated portion. The width of the protective film (the length of the protective film of the chip resistor) can be adjusted according to the uneven thickness of the resistance metal plate in the width direction, and the allowable range of adjustment of the width of the protective film (the length of the protective film of the chip resistor) can be expanded.

Technical solutions to technical problems

The method of manufacturing a metal plate low-resistance chip resistor of the first invention that solves the above-mentioned problems is characterized in that the chip resistor is manufactured by sequentially implementing the following steps using a rectangular or strip-shaped resistance metal plate: protective film Forming a step of forming a plurality of protective films in the width direction of the resistance metal plate respectively for the surface and the back surface of the resistance metal plate, the protection films extending in the length direction of the resistance metal plate; forming a slit In the step of forming a slit on the resistance metal plate, the shape of the resistance metal plate is formed into a shape having a plurality of elongated portions and connecting portions, and all adjacent parts of the slit in the width direction Between the protective films and the outer sides of the protective films on both sides of the width direction extend along the length direction of the resistance metal plate, the plurality of elongated portions have a width wider than that of the protective film and Extending in the lengthwise direction of the resistance metal plate, the connecting portions are respectively connected to both ends of the lengthwise direction of the plurality of elongated portions; the electrode plating film forming process is aimed at not forming the protective film and exposing some The two ends (2a-1, 2a-2) of the width direction of the surface (2a) and the two ends of the width direction of the back (2b) an end portion (2b-1, 2b-2) and a surface composed of both end surfaces (2c, 2d), forming an electrode plating film; a strip-shaped portion cutting step, cutting the strip-shaped portion from the connecting portion; and a strip The shape portion cutting step is to cut the elongated portion into a plurality of individual pieces.

Moreover, the manufacturing method of the metal plate low-resistance chip resistor of the 2nd invention is the manufacturing method of the metal plate low-resistance chip resistor of the 1st invention, It is characterized by performing resistance metal plate before the said protective film forming process. A thickness measuring step of measuring the thickness of each position in the width direction of the resistive metal plate on which the plurality of protective films are formed in the resistive metal plate thickness measuring step. In the protective film forming step, according to the The thickness of each position in the width direction of the resistance metal plate measured in the resistance metal plate thickness measurement step is used to set the widths of the plurality of protective films respectively.

In addition, the method of manufacturing a metal plate low-resistance chip resistor of the third invention is characterized in that the chip resistor is manufactured by sequentially implementing the following steps using a rectangular or strip-shaped resistive metal plate: a protective film forming step, Respectively for the surface and back of the resistance metal plate, a plurality of protective films are formed in the width direction of the resistance metal plate, and the protection films extend in the length direction of the resistance metal plate; the elongated cutting process, A plurality of elongated portions having a width wider than that of the protective film and extending in the longitudinal direction of the resistance metal plate are cut by cutting the resistance metal plate at a cutting position that is within the width of the resistance metal plate. Between the protection films adjacent in the direction and the outer sides of the protection films located on both sides of the width direction extend along the length direction of the resistance metal plate; the electrode plating film forming process is for the protection film not formed and forming an electrode plating film on the surface of both ends in the width direction of the elongated portion of the resistance metal plate exposed; and a single-piece cutting step of cutting the elongated portion into a plurality of individual pieces.

In addition, the manufacturing method of the metal plate low-resistance chip resistor of the fourth invention is the manufacturing method of the metal plate low-resistance chip resistor of the third invention, characterized in that the resistance metal plate is implemented before the protective film forming step. A thickness measuring step of measuring the thickness of each position in the width direction of the resistive metal plate on which the plurality of protective films are formed in the resistive metal plate thickness measuring step. In the protective film forming step, according to the The thickness of each position in the width direction of the resistance metal plate measured in the resistance metal plate thickness measurement step is used to set the widths of the plurality of protective films respectively.

Invention effect

The method of manufacturing a metal plate low-resistance chip resistor according to the first invention is characterized in that the chip resistor is manufactured by sequentially implementing the following steps using a rectangular or strip-shaped resistance metal plate: a protective film forming step, respectively For the surface and back of the resistance metal plate, a plurality of protective films are formed in the width direction of the resistance metal plate, and the protection films extend in the length direction of the resistance metal plate; A slit is formed on the resistance metal plate, the shape of the resistance metal plate is formed into a shape having a plurality of elongated portions and a connection portion, and the slit is formed between the protective films adjacent in the width direction. Between and the outer sides of the protection film on both sides of the width direction extend along the length direction of the resistance metal plate, and the plurality of elongated parts have a width wider than the protection film and are located on the resistance metal plate. Extending in the length direction of the metal plate, the connecting parts are respectively connected to the two ends of the length direction of the plurality of elongated parts; the electrode plating film forming process is aimed at not forming the protective film and exposing the resistance metal plate The surface of both ends of the width direction of the elongated portion is formed with electrode plating; the elongated portion cutting step is to cut the elongated portion from the connecting portion; and the elongated portion is cut. The elongated portion is cut into a plurality of individual pieces, so the protective film is formed prior to the slit (ie, the elongated portion).

Therefore, even if chip resistors are required to be further miniaturized and the width of the resistance metal plate in the elongated portion becomes narrower, it can be easily formed without being affected by the width of the resistance metal plate in the elongated portion. protective film. In addition, the allowable range of adjustment of the width of the protective film (the length of the protective film of the chip resistor) can be expanded (see FIG. 8 : details will be described later).

According to the manufacturing method of the metal plate low-resistance chip resistor of the second invention, in the manufacturing method of the metal plate low-resistance chip resistor of the first invention, it is characterized in that the resistance metal plate thickness is implemented before the protective film forming step. a measuring step of measuring the thickness of each position in the width direction of the resistive metal plate on which the plurality of protective films are formed in the resistive metal plate thickness measuring step; The thickness of each position in the width direction of the resistance metal plate measured in the metal plate thickness measuring step is used to set the widths of the plurality of protective films respectively. Therefore, in addition to the effects of the first invention, the width of the protective film (the length of the protective film of the chip resistor) can be adjusted according to the thickness variation in the width direction of the resistor metal plate. Therefore, variation in the resistance value of the chip resistor due to thickness variation in the width direction of the resistance metal plate can be reduced.

The method for manufacturing a metal plate low-resistance chip resistor according to the third invention is characterized in that the chip resistor is manufactured by sequentially implementing the following steps using a rectangular or strip-shaped resistance metal plate: a protective film forming step, respectively For the surface and back of the resistance metal plate, a plurality of protective films are formed in the width direction of the resistance metal plate, and the protection films extend in the length direction of the resistance metal plate; The resistance metal plate is cut at a cutting position, and a plurality of elongated portions having a width wider than the protective film and extending in the longitudinal direction of the resistance metal plate are cut, and the cutting position is in the width direction. between the protective films adjacent on the top and the outer sides of the protective films located on both sides in the width direction extend along the length direction of the resistance metal plate; the electrode plating film forming process is for the protective film not formed and exposed Electrode plating is formed on the surfaces of both ends in the width direction of the elongated portion of the resistance metal plate; Cut long strips to form a protective film.

Therefore, even if chip resistors are required to be further miniaturized and the width of the resistance metal plate in the elongated portion becomes narrower, it can be easily formed without being affected by the width of the resistance metal plate in the elongated portion. protective film. In addition, the allowable range of adjustment of the width of the protective film (the length of the protective film of the chip resistor) can be expanded (see FIG. 8 : details will be described later).

According to the manufacturing method of the metal plate low-resistance chip resistor of the fourth invention, in the manufacturing method of the metal plate low-resistance chip resistor of the third invention, it is characterized in that the resistance metal plate thickness is implemented before the protective film forming step. a measuring step of measuring the thickness of each position in the width direction of the resistive metal plate on which the plurality of protective films are formed in the resistive metal plate thickness measuring step; The thickness of each position in the width direction of the resistance metal plate measured in the metal plate thickness measurement step is used to set the widths of the plurality of protective films respectively. Therefore, in addition to the effect of the third invention, it is also possible to Adjust the width of the protective film (the length of the protective film of the chip resistor) to adjust the thickness of the resistance metal plate in the width direction. Therefore, variation in the resistance value of the chip resistor due to thickness variation in the width direction of the resistance metal plate can be reduced.

Description of drawings

FIG. 1 is a flowchart showing a manufacturing process of a metal plate low-resistance chip resistor according to an embodiment of the present invention.

Fig. 2(a) is a perspective view of a strip-shaped resistive metal plate for explaining the step of cutting a strip-shaped resistive metal plate, and Fig. 2(b) is a rectangular resistive metal plate for explaining the step of cutting a strip-shaped resistive metal plate top view.

(a) of FIG. 3 is a perspective view of a resistance metal plate for explaining the resistance metal plate thickness measurement process, and FIG. 3 (b) is a plan view of a resistance metal plate for illustrating a resistance metal plate thickness measurement process, (c) of FIG. 3 is an enlarged cross-sectional view of the resistance metal plate (enlarged cross-section along line A-A of FIG. 3( b )) for explaining the resistance metal plate thickness measurement process.

(a) of FIG. 4 is a perspective view of a resistive metal plate and the like for explaining a protective film forming process, and FIG. 4( b ) is a plan view of a resistive metal plate and the like for explaining a protective film forming process. (c) is an enlarged cross-sectional view of a resistive metal plate and the like (enlarged cross-sectional view along line B-B in FIG. 4( b )) for explaining the protective film forming process.

(a) of FIG. 5 is a perspective view of a resistance metal plate and the like for explaining a slit forming process, and FIG. 5( b ) is a plan view of a resistance metal plate and the like for explaining a slit forming process. (c) is an enlarged cross-sectional view (enlarged cross-sectional view along line C-C of FIG. 5( b )) of a resistance metal plate or the like for explaining the slit forming step.

6( a ) is a perspective view of a resistance metal plate and the like for explaining the electrode plating film forming process, and FIG. 6( b ) is a plan view of the resistance metal plate and the like for explaining the electrode plating film forming process. (c) is an enlarged cross-sectional view (enlarged cross-sectional view along line D-D of FIG. 6(b)) of a resistance metal plate and the like for explaining the electrode plating film forming process.

(a) of FIG. 7 is a perspective view of a resistance metal plate and the like for explaining the elongated portion cutting process, and FIG. 7 (b) is a perspective view for performing the elongated portion cutting process and the elongated portion cutting process. The perspective view of the elongated portion to be described, FIG. 7( c ) is a perspective view of a metal plate low-resistance chip resistor (single piece) for explaining the elongated portion cutting process.

8 is a table showing the relationship among dimensions of the metal plate low-resistance chip resistor related to the manufacturing method of the metal plate low-resistance chip resistor according to the embodiment of the present invention.

9 is a flow chart showing a manufacturing process of a metal plate low-resistance chip resistor according to another embodiment of the present invention.

Fig. 10(a) is a perspective view of a strip-shaped resistive metal plate for explaining the strip-shaped resistive metal plate cutting process, and Fig. 10(b) is a rectangular resistive metal plate for illustrating the strip-shaped resistive metal plate cutting process top view.

(a) of FIG. 11 is a perspective view of the resistance metal plate for describing the resistance metal plate thickness measurement process, and FIG. 11 (b) is a plan view of the resistance metal plate for describing the resistance metal plate thickness measurement process, (c) of FIG. 11 is an enlarged cross-sectional view of the resistance metal plate (enlarged cross-section along line A1-A1 of FIG. 11(b) ) for explaining the resistance metal plate thickness measurement step.

(a) of FIG. 12 is a perspective view of a resistive metal plate and the like for explaining a protective film forming process, and FIG. 12 (b) is a plan view of a resistive metal plate and the like for explaining a protective film forming process. (c) is an enlarged cross-sectional view (enlarged cross-sectional view along line B1-B1 of FIG. 12(b)) of a resistive metal plate or the like for explaining the protective film forming step.

(a) of FIG. 13 is a perspective view of a resistance metal plate or the like for explaining the elongated cutting process, and FIG. 13 (b) is a perspective view of an elongated part for explaining the elongated cutting process, (c) of FIG. 13 is an enlarged cross-sectional view of the elongated portion (enlarged cross-sectional view along line C1-C1 of FIG. 13(b) ) for explaining the elongated cutting step.

(a) of FIG. 14 is a perspective view of an elongated portion for describing the electrode plating film forming process, and FIG. 14 (c) is an enlarged cross-sectional view of the elongated portion for describing the electrode plating film forming process ( An enlarged cross-sectional view along line D1-D1 of (a) of FIG. 14 ).

Fig. 15(a) is a perspective view of a strip-shaped portion for explaining the single-piece cutting process, and Fig. 15(b) is a metal plate low-resistance chip resistor (single-piece) for describing the single-piece cutting process. 3D view of the sheet).

(a) of FIG. 16 is a perspective view showing the structure of a metal plate low resistance chip resistor, FIG. 16 (b) is a top view showing the structure of the metal plate low resistance chip resistor, and FIG. 16 (c) is a view showing A cross-sectional view of the structure of the metal plate low-resistance chip resistor along line E-E of FIG. 16( b ).

FIG. 17 is a flow chart showing a manufacturing process of a conventional metal plate low-resistance chip resistor.

(a) of FIG. 18 is a perspective view of a resistance metal plate for explaining a slit forming process, FIG. 18 (b) is a plan view of a resistance metal plate for illustrating a slit forming process, and FIG. 18 ( c) is an enlarged cross-sectional view of the resistance metal plate (enlarged cross-sectional view along line F-F of FIG. 18( b )) for explaining the slit forming step.

(a) of FIG. 19 is a perspective view of a resistive metal plate and the like for explaining a protective film forming process, and FIG. 19 (b) is a plan view of a resistive metal plate and the like for explaining a protective film forming process. FIG. 19 (c) is an enlarged cross-sectional view (enlarged cross-sectional view taken along line G-G of FIG. 19( b )) of a resistive metal plate and the like for explaining the protective film forming step.

FIG. 20 is a table showing the relationship among dimensions of metal plate low resistance chip resistors related to a conventional manufacturing method of metal plate low resistance chip resistors.

detailed description

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

Referring to FIGS. 1 to 7 and 16 , a method for manufacturing a chip resistor according to an embodiment of the present invention will be described. In addition, since the structure of the metal plate low-resistance chip resistor manufactured by the manufacturing method of the chip resistor of this embodiment has already been demonstrated with reference to FIG. 16, detailed description is abbreviate|omitted here.

In the present embodiment, the step of cutting the band-shaped resistance metal plate (step S11), the step of measuring the thickness of the resistance metal plate (step S12), the step of forming the protective film (step S13), and The slit forming process (step S14), the electrode coating forming process (step S15), the elongated portion cutting process (step S16) and the elongated portion cutting process (step S17), manufacture the metal structure shown in Figure 16 Board Low Resistance Chip Resistor1.

Specifically, as shown in FIG. 2(a), in the band-shaped resistance metal plate cutting process (step S11), cutting devices such as a laser, a wire electric discharge machine (Way Ya discharge), and a cutter are used to cut the strip-shaped resistance metal plate that passes through the conveyor belt. The strip-shaped resistance metal plate 2A conveyed in the direction of arrow J by a device (not shown) is cut at the position of the cutting line K indicated by a dashed-dotted line (imaginary line). The strip-shaped resistance metal plate 2A is made of FeCrAl-based, CuNi-based, or CuMn-based materials. In order to obtain a desired thickness, the material in the slab state is subjected to various processes, and the annealing process and rolling process are repeated. to manufacture.

As a result of cutting the strip-shaped resistance metal plate 2A at the cutting position, a rectangular resistance metal plate 2B shown in FIG. 2( b ) is obtained. As shown in FIG. 2( a ), positioning marks 5 are provided on both sides in the width direction and at regular intervals in the longitudinal direction on the strip-shaped resistance metal plate 2A. The positioning marks 5 are located at the front end in the longitudinal direction of the rectangular resistance metal plate 2B shown in FIG. 2( b ) and on both sides in the width direction. In addition, without being limited thereto, the positioning mark 5 may exist only on one side in the width direction, or may be provided on the rear end or center of the resistance metal plate 2B in the longitudinal direction.

As shown in Fig. 3(a) to Fig. 3(c), in the next step of measuring the thickness of the resistance metal plate (step S12), a plate thickness measuring device (not shown) is used to measure the resistance metal plate used to form a plurality of ( Thickness T at each position of the resistance metal plate 2B in the width direction (the left-right direction of FIG. ₁ , _T2 , _T3 , T4 _. Each position in the width direction of the resistance metal plate 2B for measuring the plate thickness is set with reference to the positioning mark 5 .

In the illustrated example, one position for measuring the plate thickness is set at each position in the width direction of the resistance metal plate 2B for measuring the plate thickness for each of the protective films 3A and 3B, but the present invention is not limited thereto. For example, for each of the protective films 3A and 3B, a plurality of positions for measuring the plate thickness can be respectively set at each position in the width direction of the resistance metal plate 2B for measuring the plate thickness, and will be measured at the multiple positions. The average value of the obtained thicknesses of the resistance metal plate 2B is used as the thicknesses T ₁ , T ₂ , T ₃ , and T ₄ of the resistance metal plate 2B at each position in the width direction.

As shown in Fig. 4(a) to Fig. 4(c), in the next protective film forming process (step S13), the surface 2B of the resistance metal plate 2B is formed by screen printing or photolithography. - 1 and the rear surface 2B- 2 are respectively formed with a plurality (four in the figure) of protective films 3A, 3B. The protective films 3A and 3B extend in the longitudinal direction of the resistance metal plate 2B and are parallel to each other in the width direction of the resistance metal plate 2B. In addition, the positions where the protective films 3A and 3B are formed are set with reference to the positioning marks 5 .

In addition, in the protective film forming step, based on the thicknesses T ₁ , T ₂ , and T ₃ at each position in the width direction of the resistance metal plate 2B measured in the aforementioned resistance metal plate thickness measurement step (step S12 ), , T ₄ , the respective widths of the plurality of protective films 3A, 3B (that is, the lengths of the protective films 3a, 3b of the chip resistor 1 ) L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ are set. Specifically, the widths L2 ₁ , L2 ₂ , L2 ₃ , and L2 ₄ of the protective films 3A, 3B are calculated according to the following formula (2). Formula (2) is a formula obtained by transforming Formula (1).

[mathematical formula 1]

$\begin{array}{cc}\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}\frac{\mathrm{<span\; class="notranslate">\; L</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}& <span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; ...</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

$\begin{array}{cc}\mathrm{<span\; class="notranslate">\; L</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}& <span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; ...</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In formula (1) and formula (2), R represents the resistance value (target resistance value) of the chip resistor 1, and L2 represents the length of the protective film 3a, 3b of the chip resistor 1 (that is, the protected resistance of the resistance metal plate 2). film 3a, 3b covered length), W represents the width (target value) of the chip resistor 1 (that _is , the width of the resistance metal plate 2), Tn represents the thickness of the resistance metal plate 2, and ρ represents the thickness of the resistance metal plate 2. volume resistivity. That is, the resistance value R of the chip resistor 1, the width W, the length L2, the thickness T _n (L2/(W×T _n )) of the portion covered by the protective films 3A and 3B of the resistance metal plate 2 and the The volume resistivity ρ determines.

Because the resistance value R (target resistance value), the width W (target value) determined by the elongated portion cutting process (step 17), and the volume resistivity ρ are known, the thickness Tn (that _is , the width direction of the resistance metal plate 2B) Thicknesses T ₁ , T ₂ , T ₃ , T ₄ at each position) are also known after being measured by the aforementioned resistance metal plate thickness measurement process (step S12), so use the value from the formula (2 ) can calculate the width of each protective film 3A, 3B corresponding to the thickness T ₁ , T ₂ , T ₃ , T ₄ at each position in the width direction of the resistance metal plate 2B (that is, the protective film 3a of the chip resistor 1, 3b length) L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ .

After calculating the widths L2 ₁ , L2 ₂ , L2 ₃ , and L2 ₄ of each protective film 3A, 3B, a screen pattern corresponding to the calculated value is set, and a screen printing method is performed based on the screen pattern. Here, an epoxy resin paste is printed on the front surface 2B-1 and the back surface 2B-2 of the resistance metal plate 2B, and the screen-printed paste is fired to form the protective films 3A, 3B. Of course, when photolithography or the like is used, a pattern corresponding to the calculated widths L2 ₁ , L2 ₂ , L2 ₃ , and L2 ₄ of each protective film 3A, 3B is set, and each protective film 3A, 3B is formed.

As shown in Fig. 5(a) to Fig. 5(c), in the next slit forming step (step S14), a plurality of (five in the figure in the example) slits are formed on the resistance metal plate 2B. 6. The slits 6 extend in the longitudinal direction of the resistance metal plate 2B (the up-and-down direction in FIG. 5( b )), and are formed adjacent to each other in the width direction of the resistance metal plate 2B (the left-to-right direction in FIG. 5( b )). Between the protective films 3A, 3B (that is, between the protective films 3A, 3A on the surface 2B-1 side and between the protective films 3B, 3B on the back 2B-2 side) and on both sides in the width direction of the resistance metal plate 2B The outer sides of the protective films 3A, 3B (that is, the outer sides of the protective film 3A on both sides in the width direction on the surface 2B- 1 side and the outer sides of the protective film 3B on both sides in the width direction on the back surface 2B- 2 side). In addition, the position where the slit 6 is formed is set with reference to the positioning mark 5 . By forming the plurality of slits 6, the shape of the resistance metal plate 2B becomes a shape having a plurality (four in the figure) of elongated portions 7 and connecting portions 8. The plate 2B extends in the longitudinal direction, and the connecting portions 8 connect both ends of the plurality of elongated portions 7 in the longitudinal direction (the vertical direction in FIG. 5( b )). In addition, the widths of the slits 6 in the figure are respectively widths L4 ₁ , L4 ₂ , L4 ₃ , L4 ₄ , and L4 ₅ , and the width of the resistance metal plate 2B of the elongated portion 7 (the width of the resistance metal plate 2 in the chip resistor 1 The length L3) is the width L3 ₁ , L3 ₂ , L3 ₃ , L3 ₄ , respectively.

For example, the surface of the resistive metal plate 2B including the protective films 3A, 3B is covered by exposing and developing a dry film obtained by exposing and developing a portion corresponding to the connection portion 8 and the elongated portion 7 wider than the protective films 3A, 3B, for example. 2B-1 and the back side 2B-2, and in this state, various types (various materials) suitable for the resistance metal plate 2B are sprayed onto the surface 2B-1 and the back side 2B-2 of the resistance metal plate 2B. An etching method using an etchant, whereby the slit 6 is formed by etching the resistance metal plate 2B. By forming the slit 6 by the etching method, the side surface (the surface on the side of the slit 6) 2B-5 of the resistance metal plate 2B of the elongated portion 7 becomes the surface 2B-1 and the back surface 2B of the resistance metal plate 2B. -2 These two flat surfaces are at right angles, so that the width L3 ₁ , L3 ₂ , L3 ₃ , L3 ₄ of the resistance metal plate 2B of the elongated portion 7 can be set with high precision (the resistance metal plate 2 in the chip resistor 1 length L3). In addition, the means for forming the slit 6 is not limited to the etching method, and means such as laser processing may also be used. In addition, in the illustrated example, the connecting portion 8 is formed at both ends of the elongated portion 7 in the longitudinal direction, but the present invention is not limited thereto, and the connecting portion 8 may be formed only at either end of the elongated portion 7 in the longitudinal direction.

As shown in FIG. 6( a ) to FIG. 6( c ), in the subsequent electrode plating film formation process (step S15 ), the exposed resistors for the elongated portions 7 without the protective films 3A and 3B are exposed. Electrode plating films 4A and 4B are formed on the surfaces of both ends 2B-3 and 2B-4 of the metal plate 2B in the width direction (left-right direction in FIG. 6(c) ) by electroplating. In addition, at this time, the plating film 4C is also formed on the peripheral portion of the resistance metal plate 2B such as the connection portion 8 (shown in a perspective view with a dotted line for convenience of description). As the electrode plating films 4A, 4B, nickel plating films and tin plating films are formed, for example. In addition, the electrode plating films 4A and 4B may be plated films obtained by sequentially performing nickel strike plating, copper plating, nickel plating, and tin plating.

As shown in Fig. 7(a) and Fig. 7(b), in the next elongated part cutting process (step S16), by using a cutting device such as a laser, a wire electric discharge machine, a cutter, etc. A cutting position M indicated by a dashed-dotted line (imaginary line) cuts the resistance metal plate 2B, whereby the elongated portion 7 is cut out from the connection portion 8 . One of the plurality of elongated portions 7 cut out from the connecting portion 8 is enlargedly shown in FIG. 7( b ).

As shown in Fig. 7(b) and Fig. 7(c), in the next elongated part cutting process (step S17), using a cutting device such as a laser, a wire electric discharge machine, a cutter, etc., The cutting position N indicated by the dashed-dotted line (imaginary line) cuts the elongated portion 7 into a plurality of (ten in the example in the figure) individual pieces. In this way, the metal plate low-resistance chip resistor 1 shown in (c) of FIG. 7 is manufactured. That is, by cutting the elongated portion 7 into a plurality of individual pieces, the resistance metal plate of the chip resistor 1 is formed from the resistance metal plate 2B, the protective films 3A, 3B, and the electrode plating films 4A, 4B of the elongated portion 7, respectively. 2. Protective films 3a, 3b and electrode coatings 4a, 4b.

Regarding the corresponding relationship between the size of the elongated portion 7 and the size of the chip resistor 1, the width L1 of the resistance metal plate 2B and the electrode plating films 4B, 4B of the elongated portion 7 is equivalent to the entire length L1 of the chip resistor 1, and the length L1 is equal to the length L1 of the chip resistor 1. The width C of the electrode coating films 4A, 4B of the strip-shaped portion 7 corresponds to the length C of the electrode coating films 4a, 4b of the chip resistor 1, and the width L2 of the protective films 3A, 3B of the strip-shaped portion 7 corresponds to the length C of the chip resistor 1. The length L2 of the protective films 3 a and 3 b and the width L3 of the resistance metal plate 2B of the elongated portion 7 correspond to the length L3 of the resistance metal plate 2 of the chip resistor 1 .

In addition, the above-described manufacturing process of the chip resistor including the resistance metal plate thickness measurement step is implemented for any of the rectangular resistance metal plates 2B sequentially cut out from the strip-shaped resistance metal plate 2A. This is because thickness unevenness sometimes occurs in the longitudinal direction of the strip-shaped resistance metal plate 2A, and in this case, the thickness unevenness in the width direction of each resistance metal plate 2B is different. In addition, when there is almost no thickness unevenness in the longitudinal direction of the strip-shaped resistance metal plate 2A, only the rectangular resistance metal plate 2B initially cut from the strip-shaped resistance metal plate 2A may be measured to determine the thickness. The width of the films 3A, 3B is applied to the protective films 3A, 3B formed on the second and subsequent rectangular resistance metal plates 2B cut from the strip-shaped resistance metal plate 2A.

As described above, according to the method of manufacturing a metal plate low-resistance chip resistor of this embodiment, which is a method of manufacturing a chip resistor using the rectangular resistance metal plate 2B, the chip resistor 1 is manufactured by sequentially implementing the following steps: In the protective film forming step (step S13), a plurality of protective films 3A, 3B are formed on the front surface 2B-1 and the back surface 2B-2 of the resistance metal plate 2B in the width direction of the resistance metal plate 2B. 3B extends in the longitudinal direction of the resistance metal plate 2B; the slit forming process (step S14), by forming the slit 6 on the resistance metal plate 2B, the shape of the resistance metal plate 2B is formed to have a plurality of elongated portions 7 and the shape of the connecting portion 8, the slits 6 are respectively located between the protective films 3A, 3B adjacent in the width direction and on the outer sides of the protective films 3A, 3B located on both sides in the width direction along the edge of the resistance metal plate 2B. Extending in the longitudinal direction, a plurality of elongated portions 7 have a wider width than the protective films 3A, 3B and extend in the longitudinal direction of the resistance metal plate 2B, and connecting portions 8 connect the lengths of the plurality of elongated portions 7 respectively. The two ends of direction; Electrode plating film formation process (step S15), for not being formed with protective film 3A, 3B and exposing the two ends 2B-3,2B-4 of the width direction of elongated portion 7 of resistance metal plate 2B The surface of the electrode coating 4A, 4B is formed; the elongated portion cutting process (step S16), cuts the elongated portion 7 from the connecting portion 8; and the elongated portion cutting process (step S17), the elongated portion 7 Since it is cut into a plurality of individual pieces, the protective films 3A and 3B are formed prior to the slit 6 (that is, the elongated portion 7 ).

Therefore, even if the chip resistor 1 is required to be further miniaturized and the width L3 of the resistance metal plate 2B of the elongated portion 7 becomes narrower, it is not affected by the resistance metal plate 2B of the elongated portion 7. The protective films 3A, 3B can be easily formed without affecting the width L3. That is, the protective films 3A and 3B can be easily formed by a screen printing method, a photolithography method, or the like.

In addition, the allowable range of adjustment of the width L2 of the protective films 3A and 3B (the length of the protective films 3 a and 3 b of the chip resistor 1 ) can be expanded. When referring to FIG. 8 to describe the size example of the aforementioned chip resistor 1, for example, when the length L2 of the protective film 3a, 3b is set to 0.9mm, the total length 2×C of the electrode plating film 4a, 4b is at most 0.6 mm. The overall length L1 of the chip resistor 1 is 1.5 mm and 1.1 mm in the case of mm (=2×(0.2+0.1)) and the shortest 0.2 mm (=2×(0.2−0.1)), respectively. Therefore, what is necessary is just to set the full length L1 of the chip resistor 1 to 1.5 mm (=1.6-0.1) which is the shortest allowable dimension. When the length L2 of the protective film 3a, 3b is set to 1.2 mm, the overall length 2×C of the electrode plating film 4a, 4b is the longest 0.6 mm and the shortest is 0.2 mm, the overall length of the chip resistor 1 The lengths L1 are 1.8 mm and 1.4 mm, respectively. Therefore, what is necessary is just to set the full length L1 of the chip resistor 1 in the range of 1.5-1.7 mm. When the length L2 of the protective films 3a and 3b is set to 1.5mm, the total length of the chip resistor 1 is the maximum length 2×C of the electrode plating films 4a and 4b at the maximum of 0.6mm and the minimum of 0.2mm. L1 is 2.1mm and 1.7mm, respectively. Therefore, what is necessary is just to set the full length L1 of the chip resistor 1 in the range of 1.7 mm which is the longest allowable dimension. Therefore, the allowable adjustment range of the length L2 of the protective films 3 a and 3 b is 0.6 mm, which is larger than the 0.4 mm adjustment allowable range in the conventional manufacturing method (see FIG. 20 ).

In addition, according to the manufacturing method of the metal plate low-resistance chip resistor of this embodiment, the resistive metal plate thickness measurement process (step S12) is performed before the protective film forming process (step S13), and the resistive metal plate thickness measurement process measures the thickness of a plurality of The thicknesses T ₁ , T ₂ , T ₃ , and T ₄ of the protective films 3A, 3B at respective positions in the width direction of the resistance metal plate 2B are based on the thickness measurement process of the resistance metal plate in the process of forming the protective film (step S13). The thicknesses T ₁ , T ₂ , T ₃ , and T ₄ at each position in the width direction of the resistance metal plate 2B measured in (step S12 ) set the width L2 of the plurality of protective films 3A, 3B respectively. ₁ , L2 ₂ , L2 ₃ , L2 ₄ , so the manufacturing method of the metal plate low-resistance chip resistor of this embodiment can also adjust the width of the protective films 3A, 3B according to the thickness unevenness in the width direction of the resistance metal plate 2B (The length of the protective films 3a, 3b of the chip resistor 1). Therefore, variation in the resistance value of the chip resistor 1 due to thickness variation in the width direction of the resistance metal plate 2B can be reduced.

In addition, in the manufacturing method of the metal plate low-resistance chip resistor, it is not limited to cut out the rectangular resistance metal plate 2B from the strip-shaped resistance metal plate 2A, and form the protective film 3A on the rectangular resistance metal plate 2B. , 3B, slit 6 (strip-shaped portion 7 ) and electrode coatings 4A, 4B, and then cut the strip-shaped portion 7 . That is, instead of cutting out the rectangular resistance metal plate 2B, protective films 3A, 3B, slits 6 (elongated portions 7) and electrode plating films 4A, 4B may be formed on the band-shaped resistance metal plate 2A, and then cut into long lengths. Strip part 7.

A method for manufacturing a chip resistor according to another embodiment of the present invention will be described with reference to FIGS. 9 to 16 . In addition, since the structure of the metal plate low-resistance chip resistor manufactured by the manufacturing method of the chip resistor of another embodiment has already been demonstrated with reference to FIG. 16, detailed description is abbreviate|omitted here.

In another embodiment, the band-shaped resistance metal plate cutting process (step S21), the resistance metal plate thickness measurement process (step S22), and the protective film forming process (step S23) shown in the process flow chart of FIG. , strip-shaped cutting process (step S24), electrode plating film forming process (step S25), single piece cutting process (step S26), to manufacture the metal plate low resistance chip resistor 1 of the structure shown in Fig. 16 .

Specifically, as shown in (a) of FIG. 10, in the band-shaped resistance metal plate cutting process (step S21), cutting devices such as lasers, wire electric discharge machines, and cutters are used to pass through the conveying device (not shown). Shown) The strip-shaped resistance metal plate 12A conveyed in the direction of the arrow J1 is cut at the cutting line position shown by the dashed-dotted line (imaginary line) K1. The strip-shaped resistance metal plate 12A is made of FeCrAl-based, CuNi-based or CuMn-based materials. In order to achieve the desired thickness, the material in the slab state is subjected to various processes, and the annealing process and rolling are repeated. process to manufacture.

As a result of cutting the strip-shaped resistance metal plate 12A at the cutting position, a rectangular resistance metal plate 12B shown in FIG. 10( b ) is obtained. As shown in FIG. 10( a ), positioning marks 15 are provided at regular intervals in the longitudinal direction on both sides of the strip-shaped resistance metal plate 12A in the width direction. The positioning marks 15 are located at the front end in the longitudinal direction of the rectangular resistance metal plate 12B as shown in FIG. 10( b ), and are located on both sides in the width direction. In addition, not limited thereto, the positioning mark 15 may be provided only on one side in the width direction, or may be provided at the rear end or center of the resistance metal plate 12B in the longitudinal direction.

As shown in Fig. 11(a) to Fig. 11(c), in the next resistance metal plate thickness measurement process (step S22), a plate thickness measuring device (not shown) is used to measure the resistance metal plate used to form a plurality of ( The thickness T at each position of the resistance metal plate 12B in the width direction (left and right direction of FIG. ₁ , T2, _T3 , _T4 , _T5 , _T6 , _{T7 .} Each position in the width direction of the resistance metal plate 12B for measuring the plate thickness is set with reference to the positioning mark 15 .

In the illustrated example, one position for measuring the plate thickness is set at each position in the width direction of the resistance metal plate 12B for measuring the plate thickness for each of the protective films 13A and 13B, but the present invention is not limited thereto. For example, for each of the protective films 13A and 13B, a plurality of positions for measuring the thickness of the plate can be set at each position in the width direction of the resistance metal plate 12B used for measuring the plate thickness, and the position measured at the plurality of positions The average value of the thickness of the resistive metal plate 12B is taken as the thickness T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , and T ₇ at each position in the width direction of the resistive metal plate 12B.

As shown in Fig. 12(a) to Fig. 12(c), in the next protective film forming process (step S23), the surface 12B of the resistance metal plate 12B is formed by screen printing or photolithography. - 1 and the rear surface 12B- 2 are formed with a plurality of (seven in the figure as an example) protective films 13A, 13B, respectively. The protective films 13A and 13B extend in the longitudinal direction of the resistance metal plate 12B and are parallel to each other in the width direction of the resistance metal plate 12B. In addition, the positions where the protective films 13A and 13B are formed are set with reference to the positioning marks 15 .

In addition, in this protective film forming step, based on the thicknesses T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , T ₇ set the respective widths of the plurality of protective films 13A, 13B (that is, the lengths of the protective films 3a, 3b of the chip resistor 1) L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ , L2 ₅ , L2 ₆ , L2 ₇ . Specifically, the widths L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ , L2 ₅ , L2 ₆ , and L2 ₇ of the protective films 13A, 13B are calculated according to the following formula (4). Formula (4) is obtained by transforming formula (3).

[mathematical formula 2]

$\begin{array}{cc}\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}\frac{\mathrm{<span\; class="notranslate">\; L</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}& <span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; ...</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

$\begin{array}{cc}\mathrm{<span\; class="notranslate">\; L</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}& <span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; ...</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In formula (3) and formula (4), R represents the resistance value (target resistance value) of the chip resistor 1, and L2 represents the length of the protective film 3a, 3b of the chip resistor 1 (that is, the protected resistance of the resistance metal plate 2). film 3a, 3b covers the length), W represents the width (target value) of the chip resistor 1 (that is, the width of the resistance metal plate 2), T _n represents the thickness of the resistance metal plate 2, ρ represents the volume of the resistance metal plate 2 resistivity. That is, the resistance value R of the chip resistor 1 is the width W, the length L2, the thickness T _n (L2/(W×T _n )) of the part covered by the protective films 3a and 3b of the resistance metal plate 2 and the resistance value of the resistance metal plate 2. Determined by the volume resistivity ρ.

Since the resistance value R (target resistance value), the width W (target value) determined by the single-piece cutting process (step 26) and the volume resistivity ρ are known, and the thickness Tn (that _is , the width direction of the resistance metal plate 12B Thickness T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , T ₇ ) at each position is also known after being measured in the aforementioned resistance metal plate thickness measurement process (step S22), so it can be used Described value and according to described formula (4), calculate and correspond to the thickness T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , T ₇ at each position in the width direction of the resistance metal plate 12B The widths of the protective films 13A, 13B (that is, the lengths of the protective films 3a, 3b on the chip resistor 1) L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ , L2 ₅ , L2 ₆ , L2 ₇ .

After calculating the width L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ , L2 ₅ , L2 ₆ , L2 ₇ of each protective film 13A, 13B, set the screen pattern corresponding to the calculated value, and based on the screen The screen printing method is implemented for the mesh pattern, whereby epoxy-based resin paste is printed on the surface 12B-1 and the back surface 12B-2 of the resistance metal plate 12B, and by sintering the screen-printed paste, The respective protective films 13A, 13B are formed. Of course, when photolithography or the like is used, patterns corresponding to the calculated values of the widths L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ , L2 ₅ , L2 ₆ , and L2 ₇ of the respective protective films 13A, 13B are set, and The respective protective films 13A, 13B are formed.

As shown in Figure 13(a) to Figure 13(b), in the next elongated cutting process (step S24), the resistance metal The plate 12B is cut at a cutting position M1 indicated by a dashed-dotted line (imaginary line), and a plurality of (seven in the figure, for example) elongated portions 17 are cut out. (b) of FIG. 13 shows enlarged one of the plurality of elongated portions 17 cut out from the resistance metal plate 12B, and (c) of FIG. 13 shows an enlarged cross section of this elongated portion 17 . (b) of FIG. 13 shows the width L3 of the resistance metal plate 12B of the elongated portion 17 (the length L3 of the resistance metal plate 2 of the chip resistor 1 ), and the widths of the protective films 13A, 13B of the elongated portion 17. L2 (the length L2 of the protective films 3a, 3b in the chip resistor 1).

As shown in (a) of FIG. 13 , the cutting position (cutting line) M1 extends in the longitudinal direction of the resistance metal plate 12B (the vertical direction of FIG. 12( b )), and is set in the width direction of the resistance metal plate 12B. (the left-right direction of (b) of FIG. 12 ) between the adjacent protective films 3A and 3B (that is, between the protective films 13A and 13A on the front surface 12B-1 side and between the protective films 13B and 13B on the back surface 12B-2 side) ) and the outer sides of the protective films 13A and 13B located on both sides in the width direction of the resistance metal plate 12B (that is, the outer sides of the protective film 13A on both sides in the width direction on the surface 12B-1 side and on both sides in the width direction on the back side 12B-2 side outside of the protective film 13B). The cutting position (cutting line) M1 is set with reference to the positioning mark 15 so that the width L3 of the resistance metal plate 12B of the elongated portion 17 becomes a predetermined value. In addition, by properly adjusting the cutting width of cutting devices such as lasers, wire electric discharge machines, and cutters (that is, the width of the cutting position (cutting line) M1 determined by the width of the laser beam, the thickness of the line, and the thickness of the cutting blade, etc.) , the width L3 of the resistance metal plate 12B of the elongated portion 17 can also be adjusted.

As shown in (b) of FIG. 13, (c) of FIG. 13 and (a) of FIG. 14, (b) of FIG. 17. For the surfaces of both ends 12B-3, 12B-4 of the resistance metal plate 12B exposed in the width direction (the left-right direction of FIG. 13(b)) without forming the protective films 13A, 13B, electrodes are formed by electroplating. Coated films 14A, 14B. In addition, at this time, the plating films 14C and 14D are also formed at both ends in the longitudinal direction of the elongated portion 17 where the protective films 13A and 13B are not formed. As the electrode plating films 14A, 14B, nickel plating films and tin plating films are formed, for example. In addition, the electrode plating films 14A and 14B may be plated films formed by sequentially performing strike nickel plating, copper plating, nickel plating, and tin plating.

As shown in (a) of FIG. 15 , in the next single-piece cutting process (step S26), the elongated portion 17 is cut by a single-dot chain line using a cutting device such as a laser, a wire electric discharge machine, or a cutter The cutting position N1 shown by the (imaginary line) cuts into a plurality (12 pieces in the illustrated example) of individual pieces. In this way, the metal plate low-resistance chip resistor 1 shown in (b) of FIG. 15 is manufactured. That is, by cutting the elongated portion 17 into a plurality of individual pieces, the resistance metal plates of the chip resistor 1 are respectively formed from the resistance metal plate 12B, the protective films 13A, 13B, and the electrode plating films 14A, 14B of the elongated portion 17. 2. Protective films 3a, 3b and electrode coatings 4a, 4b.

Regarding the corresponding relationship between the size of the elongated portion 17 and the size of the chip resistor 1, the width L1 of the resistance metal plate 12B and the electrode plating films 14B, 14B of the elongated portion 17 is equivalent to the entire length L1 of the chip resistor 1, and the length L1 is equal to the length L1 of the chip resistor 1. The width C of the electrode plating films 14A, 14B of the strip portion 17 is equivalent to the length C of the electrode plating films 4a, 4b in the chip resistor 1, and the width L2 of the protective films 13A, 13B of the elongated portion 17 is equivalent to the length C of the chip resistor 1. The length L2 of the protective films 3 a and 3 b and the width L3 of the resistance metal plate 12B of the elongated portion 17 correspond to the length L3 of the resistance metal plate 2 of the chip resistor 1 .

In addition, the above-described manufacturing process of the chip resistor including the resistance metal plate thickness measurement step is implemented for any of the rectangular resistance metal plates 12B sequentially cut out from the strip-shaped resistance metal plate 12A. This is because thickness unevenness may also occur in the longitudinal direction of the strip-shaped resistance metal plate 12A, and in this case, the thickness unevenness in the width direction of each resistance metal plate 12B is different. In addition, when there is substantially no thickness unevenness in the longitudinal direction of the strip-shaped resistance metal plate 12A, it is also possible to measure the thickness of the rectangular resistance metal plate 12B initially cut from the strip-shaped resistance metal plate 12A and determine the protective film. 13A, 13B, and apply the width of the protective films 13A, 13B to the protective films 13A, 13B formed on the second and subsequent rectangular resistive metal plates 12B cut from the strip-shaped resistive metal plate 12A.

As described above, also in the manufacturing method of the metal plate low-resistance chip resistor of another embodiment, the same effects as those of the manufacturing method of the metal plate low-resistance chip resistor of the above-mentioned embodiment can be obtained.

That is, the method of manufacturing a metal plate low-resistance chip resistor according to another embodiment of the present invention is a method of manufacturing a chip resistor 1 using a rectangular resistance metal plate 12B, and the chip resistor is manufactured by sequentially implementing the following steps 1: Protective film forming process (step S23), respectively for the surface 12B-1 and the back surface 12B-2 of the resistance metal plate 12B, form a plurality of protection films 13A, 13B in the width direction of the resistance metal plate 12B, and a plurality of protection films The films 13A, 13B extend in the longitudinal direction of the resistance metal plate 12; the elongated cutting process (step S24), by cutting the resistance metal plate 12B at the cutting position M1, cuts have a width wider than the protection films 13A, 13B and For the plurality of elongated portions 17 extending in the longitudinal direction of the resistance metal plate 12B, the cutting positions M1 are respectively between the protective films 13A and 13B adjacent in the width direction and the protective films 13A located on both sides of the width direction. , 13B along the length direction of the resistance metal plate 12B; The surfaces of both end portions 12B-3, 12B-4 are formed with electrode coatings 14A, 14B; and the single-piece cutting process (step S26), the strip-shaped portion 17 is cut into a plurality of single pieces, so prior to cutting the strip-shaped Protective films 13A and 13B are formed on the portion 17 .

Therefore, even when the chip resistor 1 is required to be further miniaturized and the width L3 of the resistance metal plate 12B of the elongated portion 17 becomes narrower, for example, it is not affected by the resistance metal plate 12B of the elongated portion 17. The protective films 13A, 13B are easily formed due to the influence of the width L3. That is, the protective films 13A, 13B can be easily formed by a screen printing method, a photolithography method, or the like.

In addition, the allowable range of adjustment of the width L2 of the protective films 13A and 13B (length of the protective films 3 a and 3 b of the chip resistor 1 ) can be expanded (see FIG. 8 ).

In addition, according to the method of manufacturing a metal plate low-resistance chip resistor according to another embodiment of the present invention, since the resistive metal plate thickness measurement process (step S22) is performed before the protective film forming process (step S23), the resistive metal plate thickness measurement step In the process, the thicknesses T ₁ , T ₂ , T ₃ , T ₄ , T ₅ , T ₆ , and T ₇ at each position in the width direction of the resistance metal plate 12B forming a plurality of protective films 13A, 13B are measured, In the process (step S23), the thicknesses T ₁ , T ₂ , T ₃ , T ₄ , and T ₅ at each position in the width direction of the resistance metal plate 12B measured in the resistance metal plate thickness measurement process (step S22 ) , T ₆ , T ₇ set the width L2 ₁ , L2 ₂ , L2 ₃ , L2 ₄ , L2 ₅ , L2 ₆ , L2 ₇ of a plurality of protective films 13A, 13B respectively, so it can also be based on the width of the resistance metal plate 12B The width of the protective films 13A and 13B (the length of the protective films 3 a and 3 b of the chip resistor 1 ) is adjusted according to the thickness variation in the direction. Therefore, the variation in the resistance value of the chip resistor 1 due to the thickness variation in the width direction of the resistance metal plate 12B can be reduced.

In addition, in the manufacturing method of the metal plate low-resistance chip resistor described above, the rectangular resistance metal plate 12B is cut out from the strip-shaped resistance metal plate 12A, and the protective films 13A, 13B are formed on the rectangular resistance metal plate 12B. , and then cut the elongated portion 17, but not limited thereto. That is, instead of cutting out the rectangular resistance metal plate 12B, the elongated portion 17 may be cut out after forming the protective films 13A and 13B on the strip-shaped resistance metal plate 12A.

Industrial Applicability

The present invention relates to a method of manufacturing a chip resistor using a resistance metal plate, and is particularly suitable for use when the width of the resistance metal plate in the elongated portion is very narrow in the manufacturing process of the chip resistor.

Explanation of reference signs

1 metal plate low resistance chip resistor, 2 resistance metal plate, 2A strip resistance metal plate, 2B rectangular resistance metal plate, 2B-1 surface, 2B-2 back, 2B-3, 2B-4 end, 2B -5 side, 2a surface, 2a-1, 2a-2 end, 2b back, 2b-1, 2b-2 end, 2c, 2d end, 2e, 2f end, 3a, 3b protective film, 3A, 3B Protective film, 4a, 4b electrode coating, 4A, 4B electrode coating, 4C coating, 5 positioning mark, 6 slit, 7 strip-shaped part, 8 connecting part, 12A strip-shaped resistance metal plate, 12B rectangular resistance metal plate , 12B-1 surface, 12B-2 back, 12B-3, 12B-4 ends, 14A, 14B electrode coating, 14C, 14D coating, 15 positioning marks, 17 strips.

Claims (4)

1. a manufacture method for metal plate low-resistance chip resistor, is characterized in that, using the resistance metallic plate of rectangle or band shape, manufacturing described chip resister by implementing following operation successively:

Diaphragm formation process, respectively for surface and the back side of described resistance metallic plate, the Width of described resistance metallic plate is formed multiple diaphragm, and described diaphragm extends on the length direction of described resistance metallic plate;

Slit formation process, by forming slit on described resistance metallic plate, the shape of described resistance metallic plate is formed as the shape with multiple strip portion and connecting portion, between the described diaphragm that described slit is adjacent on described Width and the outside of the described diaphragm being positioned at described Width both sides extends along the length direction of described resistance metallic plate, described multiple strip portion has the width wider than described diaphragm and extends on the length direction of described resistance metallic plate, described connecting portion connects the two ends of the length direction in described multiple strip portion respectively,

Electrode metallizations formation process, for not being formed with described diaphragm and exposing the face be made up of the both ends (2a-1,2a-2) of Width of (2a), surface, the both ends (2b-1,2b-2) of the Width of the back side (2b) and both ends of the surface (2c, 2d) having the both ends of the Width in the described strip portion of described resistance metallic plate, form electrode metallizations;

Strip portion cuts operation, cuts described strip portion from described connecting portion; And

Strip portion cuts off operation, and described strip portion is cut into multiple monolithic.

2. the manufacture method of metal plate low-resistance chip resistor according to claim 1, is characterized in that,

Before described diaphragm formation process, implement resistance metallic plate thickness measure operation, in described resistance metallic plate thickness measure operation, measure the thickness of each position of the Width of the described resistance metallic plate forming described multiple diaphragm,

In described diaphragm formation process, according to the thickness of each position of the Width of the described resistance metallic plate measured in described resistance metallic plate thickness measure operation, set the width of described multiple diaphragm respectively.

3. a manufacture method for metal plate low-resistance chip resistor, is characterized in that, using the resistance metallic plate of rectangle or band shape, manufacturing described chip resister by implementing following operation successively:

Diaphragm formation process, respectively for surface and the back side of described resistance metallic plate, the Width of described resistance metallic plate is formed multiple diaphragm, and described diaphragm extends on the length direction of described resistance metallic plate;

Strip cuts off operation, by cutting off described resistance metallic plate in off-position, cut and have the width wider than described diaphragm and the multiple strip portions extended on the length direction of described resistance metallic plate, between the described diaphragm that described off-position is adjacent on described Width and the outside of the described diaphragm being positioned at described Width both sides extends along the length direction of described resistance metallic plate;

Electrode metallizations formation process, for not being formed with described diaphragm and exposing the surface at the both ends of the Width in the described strip portion having described resistance metallic plate, forms electrode metallizations; And

Monolithic cuts off operation, and described strip portion is cut into multiple monolithic.

4. the manufacture method of metal plate low-resistance chip resistor according to claim 3, is characterized in that,

Before described diaphragm formation process, implement resistance metallic plate thickness measure operation, in described resistance metallic plate thickness measure operation, measure the thickness of each position of the Width of the described resistance metallic plate forming described multiple diaphragm,

In described diaphragm formation process, according to the thickness of each position of the Width of the described resistance metallic plate measured in described resistance metallic plate thickness measure operation, set the width of described multiple diaphragm respectively.