JP5544824B2 - Manufacturing method of chip resistor - Google Patents

Description

  The present invention relates to a method of manufacturing a low-resistance chip resistor suitable for current detection applications, and in particular, a metal plate resistor in which electrodes made of a metal conductor having high conductivity are fixed at both ends of a metal plate resistor made of a resistance alloy material. The present invention relates to a method for manufacturing a container.

  A solder connection electrode made of a metal conductor having a high conductivity such as Cu is fixed to both ends of a metal plate resistor made of a resistance alloy material such as a Cu-Ni alloy or a Ni-Cr alloy. A chip resistor having a resistance value is known.

  Conventionally, in this type of chip resistor, a notch groove is provided by laser processing or the like in a portion between both electrodes of the metal plate resistor, and a detour is formed in the current flow path, thereby reducing the resistance value of the resistor. Adjustment to a predetermined value is performed (see Patent Documents 1 and 2).

JP 2002-57009 A JP 2006-228980 A

  In order to process such a metal plate resistor with a laser, considerable output is required and processing time is required, which is disadvantageous in terms of manufacturing cost. Conventionally, the notch is formed while measuring the resistance value, but there is a problem that handling is difficult in the state of each chip resistor. Since the thickness of the metal plate is stable, if the punching shape when the metal plate is divided into chip resistors is stable, the resistance value is within a certain range. However, there are cases where fine adjustment of the resistance value is required for high accuracy requirements. Further, if the resistance value can be adjusted in accordance with the product specification, it is possible to manufacture a plurality of types of resistance value specification products on a single production line, thereby improving efficiency.

  The present invention has been made based on the above-described circumstances, and can be manufactured at a low cost with a simple manufacturing process, and a chip resistor manufacturing method using a metal plate resistor capable of responding to various resistance value specifications. The purpose is to provide.

The chip resistor manufacturing method of the present invention includes a step of preparing a metal plate made of a predetermined resistance material, a step of forming a through hole in the metal plate by punching, and a protective film covering a predetermined region including the through hole. forming, comprise a portion of the through hole covered with the protective film, a region including the metal plate leaving on both sides of the protective film, one chip by defining it have punching the periphery by punching And a separation step of making a resistor .

According to the present invention, a through hole is formed in a metal plate by punching, and after forming a protective film and an electrode film, punching is performed to form individual pieces. Can be mass-produced. As a result, a chip resistor using a metal plate resistor can be mass-produced with a simple manufacturing process at low cost, and various resistance value specifications can be supported.

(A) (b) (c) is a top view which shows the formation step of the through-hole of Example 1 of this invention. (A) and (b) are a plan view showing a formation stage of a protective film and a cross-sectional view along the line xx, (c) a cross-sectional view showing a formation stage of an electrode film, and (d) is an individualization. FIG. 5E is a plan view and a cross-sectional view of a chip resistor separated into individual pieces. It is a perspective view of the said chip resistor. 2A and 2B are a plan view and a cross-sectional view illustrating a method for forming a through hole A. 2A and 2B are a plan view and a cross-sectional view illustrating a method for forming a through hole B. It is a top view which shows the example of various shapes of a through-hole. It is a top view which shows the structural example of a chip resistor. It is a top view which shows the other structural example of a chip resistor. (A) is a top view which shows the formation stage of the protective film of Example 2 of this invention, (b) is a top view which shows a part punching trimming stage, (c) is a plane which shows an individualization stage It is a figure and (d) is a top view of the chip resistor separated into pieces.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 9. In addition, in each figure, the same code | symbol is attached | subjected and demonstrated to the same or equivalent member or element.

  1 and 2 show a manufacturing process of a chip resistor using a metal plate resistor of Example 1 of the present invention. First, as shown in FIG. 1A, a sheet-like metal plate 11 that is a resistance alloy material plate material such as a Cu—Ni-based material or a Ni—Cr-based material is prepared. The metal plate 11 is obtained by cutting a long metal material that has been rolled into a predetermined size. Then, a probe is applied to a predetermined portion of the metal plate 11 and the resistance value of the metal plate 11 is measured. Although the thickness of the rolled metal material is stable, the resistor of the present invention requires very high-accuracy characteristics. Therefore, the resistance of the metal plate 11 itself varies slightly (mainly The thickness variation) affects the accuracy of the resulting resistor.

  Therefore, the resistance value of the metal plate 11 is measured in advance, and the relative positional relationship between the first through hole A and the second through hole B is determined from the obtained resistance value. That is, the resistance value variation between one metal plate 11 and another metal plate 11 is adjusted by finely adjusting the formation positions of the first through hole A and the second through hole B. Subsequently, the 1st through-hole A which straddles one side edge of the resistor area | region 12 used as the piece shown with a broken line in a figure is formed by the punching process by a press. The resistor regions 12 are arranged in a matrix on the metal plate 11 as shown in the figure. First, first through holes A are formed in each resistor region 12 for the uppermost row 12A.

  And as shown in FIG.1 (b), the 2nd through-hole B ranging over the other side edge of the resistor area | region 12 is sequentially formed in each resistor area | region 12 by punching process about the 1st row | line 12A. Thereby, the first through hole A and the second through hole B are formed in each resistor region 12 of the first row 12A.

  Next, as shown in FIG. 1C, first through holes A are first formed by punching in each resistor region 12 of the second row 12B, and after that, the second through holes B are formed by punching. Repeat the forming process. Thereby, the first through hole A and the second through hole B are sequentially formed in each resistor region 12 of the second row 12B. And although not shown in figure, the same process is repeated about the resistor area | region 12 below a 3rd row, and a 1st through-hole and a 2nd through-hole are arrange | positioned in the resistor area | region of the whole surface of a metal plate.

  Next, as shown in FIGS. 2A and 2B, a protective film 13 covering the region including the first through hole A and the second through hole B is formed on the upper surface of the metal plate 11. As shown in the figure, the protective film 13 is formed in a strip-like pattern so as to cover the central portion of the resistor region 12, and both sides thereof become exposed surfaces of the metal plate 11. The protective film 13 may be a lattice pattern for each resistor region shown in FIG. A protective film 14 is formed on the lower surface of the metal plate 11 to cover substantially the entire surface. As a material for the protective films 13 and 14, an epoxy resin or the like is suitable. The protective film 13 may be formed after the protective film 14 is formed.

  Then, as shown in FIG. 2C, an electrode film 15 made of a metal material that becomes an electrode is formed on the exposed portion of the metal plate 11 that is not covered with the protective film 13. The electrode film 15 is preferably formed by plating on the exposed surface of the metal plate 11 made of a resistance alloy material, on which the protective film 13 is not formed. As an example, the metal layers are formed in an order of Cu, Ni, and Sn by electrolytic plating. In addition to the above, the electrode film can be formed by sputtering, vapor deposition, or the like. In this case, the portions such as the protective film 13 where the metal film is not formed are covered with a resist or a metal mask. In addition, the electrode film 15 may be formed by screen printing of an electrode paste. In consideration of the manufacturing process, connection reliability, and the like, it is preferable to form by an electrolytic plating method.

  Next, as shown in FIGS. 2D and 2E, it is separated into individual pieces by punches for individual piece punching. That is, it is a region where the protective film 13 is formed between the pair of electrode films 15 and 15 on the metal plate 11 and the electrode film, and a part of the first through hole A and one of the second through holes B. The chip resistor 20 shown in FIGS. 2E and 2F is obtained by punching the resistor region 12 including the portion by punching along the broken line. Although the illustrated example shows only one section, a large number of chip resistors 20 can be obtained from one metal plate sheet by punching by punching along the broken lines of each resistor region 12.

  FIG. 3 is a perspective view of the chip resistor 20. Electrode coatings 25, 25 made of a plating layer or the like are provided on both ends of the lower surface of the resistor 21 made of a resistance alloy material such as a Cu—Ni-based or Ni—Cr-based material. The metal plate resistor 21 is provided with a first through hole A and a second through hole B which are elongated holes extending in a direction orthogonal to the electrode arrangement direction, thereby forming a current detour and obtaining a required resistance value. Adjusted. The upper surface of the metal plate resistor 11 is covered with a protective film 14, which is a chip resistor suitable for surface mounting that can obtain a highly accurate low resistance value of about milliohms.

  4 and 5 show specific examples of forming the through holes A and B by punching. The pedestal 31 is a frame-shaped jig fixed to the outer periphery / periphery of the metal plate 11 and moves vertically and horizontally to define the punch position. The metal plate 11 is provided with a positioning hole 17, which is fixed to the pedestal 11 by a pin 31a, and the pedestal 31 moves to align the through hole forming portion of the metal plate 11. The positions of the punch 32 and the die 33 are fixed, the pedestal 31 moves, and the punch 32 descends after alignment, thereby forming a through hole in the metal plate 11.

  FIG. 4 shows an example of forming the through hole A. After the through hole A is formed in the leftmost resistor region 12, the pedestal 31 moves, and the through hole A is formed in the next resistor region 12 by the punch 32 and the die 33. In addition, it is shown that the position moves to the formation position of the through hole A in the next resistor region 12. When the formation of the through holes A is completed for one row, the through holes B are formed in the same manner as described above, as shown in FIG. When the formation of the through-holes A and B is completed for one row, the process moves to the next row, and the through-holes A and B are similarly formed. B is formed. Although the above example is an example in which through holes are formed one by one, punches that form through holes at a plurality of locations at a time may be used.

  FIG. 6 shows various shape examples of the through holes. Although various shapes of the through holes are conceivable, as shown in FIGS. 6A and 6B, it is preferable to have a rounded shape so that the current path is smooth. Also, as shown in FIGS. 6A and 6C, it is preferable to have a long hole shape so that the adjustment range of the resistance value can be made relatively wide. Accordingly, the shape of the long hole shown in FIG.

  The punched shape of the resistor 21 is also preferably rounded at the corners. If the shape is square, burrs may occur or the transport device or packing material may be damaged when transporting or packing individual chip resistors. When the resistor 21 is punched, a single mold is used. For this reason, the punching shape is stable and there is almost no variation in product dimensions. On the other hand, the resistance value variation of the metal plate 11 itself is suppressed by adjusting the positions where the through holes A and B are formed. The value can be kept highly accurate.

  FIG. 7 shows an example of a specific structure / dimension of the resistor 20, and is an example in which one through hole A, B is formed from each side surface of the resistor. When the resistors are singulated, it is preferable that the through holes A and B are point-symmetrical at the intersection point O (center of the resistor) O of the central axes A and B. If it is not point-symmetric, there will be a problem that the directivity of components such as inductance changes depending on the mounting direction.

The resistor 21 is a Ni—Cr resistance alloy material, has a thickness of 0.1 mm, and a specific resistance = 130 μΩ · cm. The electrode 25 is a Cu plating layer. Examples of dimensions are b = 0.2, e = 0.35, f = 1.30, and g = 1.25 (unit: mm).
Examples of the resistance value (mΩ) corresponding to the through hole cutting depth a (mm) and the ratio of the cutting depth a to the resistor width g a / g (%) are as follows.

  As shown in the table, the resistance value can be adjusted by adjusting the depth a. For this reason, if the resistance value of the metal plate 11 before solidification is measured in advance, the resistance value when the metal plate 11 is separated can be calculated. Therefore, if the depth a is determined from the calculation result, it can be obtained. The resistance value of the resistor can be made more accurate. In addition, about a / g (how much cutting is made with respect to the width of the resistor), it is preferable to set the upper limit to 70%. If the width is extremely narrow in a part of the resistor, it is not preferable in terms of strength, characteristics, etc. of the resistor. Further, b is determined in relation to the thickness of the resistance material in terms of press working. In general, the thickness is preferably about 1.5 to 2 times the thickness of the resistance material. In this example, the depth a is adjusted, but the distance d between the through holes A and B can also be adjusted.

  The arrangement of the through holes may be as shown in FIG. However, in the same manner as described above, it is preferable that there is no directivity in consideration of inductance at the time of mounting. For this reason, it is preferable that the through holes D and E have the same y length, are arranged symmetrically with respect to the central axis B, and the through holes C are arranged on the central axis C. For example, the resistance value may be adjusted such that y is constant and only x is variable.

  FIG. 9 shows a manufacturing process of the metal plate chip resistor according to the second embodiment of the present invention. The formation process of the through holes A and B is the same as that shown in FIGS. FIG. 9 (a) is a diagram corresponding to FIG. 2 (a) of the first embodiment, but the pattern of the protective film 13a of the present embodiment is a lattice shape divided for each resistor region 12 as shown in the figure. The pattern is (matrix). With such a pattern, the amount of insulating material used for the protective film can be reduced. In addition, when the electrode film is formed by electrolytic plating, this contributes to reduction in film thickness variation, suppression of warpage of the metal plate 11, and the like.

  FIG. 9B shows a partial punching of the resistor region 12 and a resistance value adjusting process. In this embodiment, a region 40 indicated by hatching in the drawing is punched by punching. As a result, only one side of the electrode (broken line portion denoted by reference numeral 41) is connected to the base metal plate 11, and the other side of the electrode is insulated and separated. In this way, since the resistance values of the individual resistors can be measured by bringing the probes 42 and 42 into contact with the electrodes 15 and 15, the resistance value can be further reduced by a method such as cutting the side surface of the resistor with a cutting tool. Fine adjustment is possible. Since the resistance value has already been roughly adjusted by the through holes A and B, the fine adjustment here is simple.

  And the chip | tip resistor 20 separated into pieces is obtained by cut | disconnecting the side 41 of the resistor area | region which is a connection part with the base metal plate 11 by punching. The chip resistor 20 has the same structure shown in FIG. 3 as that manufactured by the manufacturing method of the first embodiment. Although the illustrated example shows only one section, it is the same as in the first embodiment that a large number of chip resistors can be obtained from one metal plate by sequentially cutting the side 41 by punching.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for manufacturing a chip resistor in which electrodes made of a metal conductor having high conductivity are fixed to both ends of a metal plate resistor made of a resistance alloy material.

Claims (7)

Preparing a metal plate made of a predetermined resistance material;
Forming a first through hole in a metal plate by punching;
Forming a second through hole by punching a metal plate after forming the first through hole;
Forming a protective film covering a region including the first through hole and the second through hole;
Forming an electrode film made of a metal material to be an electrode on the exposed portion of the resistive material not covered with the protective film;
A pair of electrode coating, a region where the protective film is formed between the electrode coating, a part of the first through hole, a region including a portion of the second through-hole, and have punching by punching A chip resistor manufacturing method comprising the step of dividing into one chip resistor.   The method for manufacturing a chip resistor according to claim 1, wherein the first through hole and the second through hole have a long hole shape extending in a direction orthogonal to the electrode arrangement direction.   The manufacturing method of the chip resistor according to claim 1, wherein the formation position of the first through hole and / or the second through hole is adjusted in a direction orthogonal to the electrode arrangement direction.   The singulation step is stamped so that a part of the first through hole and a part of the second through hole are point-symmetric or line-symmetric with respect to the center of the singulated resistor. 2. A method for manufacturing a chip resistor according to 1.   Resistor areas are arranged in a matrix on the metal plate, and first through holes are sequentially formed in each row of resistor areas, and then second through holes are sequentially formed. The manufacturing method of the chip resistor according to claim 1 which arranges the 1st penetration hole and the 2nd penetration hole in a device field. Preparing a metal plate made of a predetermined resistance material;
  Forming a through hole in a metal plate by punching;
  Forming a protective film covering a predetermined region including the through hole; and
  Separation of a region including a part of a through hole covered with a protective film and including a metal plate protruding on both sides of the protective film by punching the periphery by punching to form one chip resistor And a method of manufacturing a chip resistor. The separation step includes a first separation step in which a part is connected to the base metal plate,
  The chip resistor manufacturing method according to claim 6, further comprising a second separation step in which a part connected to the base metal plate is cut to form one chip resistor.

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