WO2021153153A1 - Manufacturing method for resistor, and resistor - Google Patents

Manufacturing method for resistor, and resistor Download PDF

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Publication number
WO2021153153A1
WO2021153153A1 PCT/JP2020/049196 JP2020049196W WO2021153153A1 WO 2021153153 A1 WO2021153153 A1 WO 2021153153A1 JP 2020049196 W JP2020049196 W JP 2020049196W WO 2021153153 A1 WO2021153153 A1 WO 2021153153A1
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WIPO (PCT)
Prior art keywords
resistor
electrode body
recess
base material
present
Prior art date
Application number
PCT/JP2020/049196
Other languages
French (fr)
Japanese (ja)
Inventor
航児 江藤
陽平 常盤
玲那 金子
純平 山本
Original Assignee
Koa株式会社
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Publication of WO2021153153A1 publication Critical patent/WO2021153153A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C1/00—Details
    • H01C1/14—Terminals or tapping points or electrodes specially adapted for resistors; Arrangements of terminals or tapping points or electrodes on resistors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C13/00—Resistors not provided for elsewhere
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
    • H01C17/22—Apparatus or processes specially adapted for manufacturing resistors adapted for trimming
    • H01C17/24—Apparatus or processes specially adapted for manufacturing resistors adapted for trimming by removing or adding resistive material
    • H01C17/242—Apparatus or processes specially adapted for manufacturing resistors adapted for trimming by removing or adding resistive material by laser
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
    • H01C17/28—Apparatus or processes specially adapted for manufacturing resistors adapted for applying terminals

Definitions

  • the present invention relates to a method for manufacturing a resistor and a resistor.
  • JP2009-071123A discloses a resistor in which a pair of electrodes are welded to both end faces of the resistor as a resistor for current detection.
  • the resistance value is adjusted by trimming a part of the resistor, but when trimming is performed at an arbitrary position on the resistor, the heat distribution of the resistor is designed.
  • the heat distribution will be different from that of the above, and there is a risk that the resistor after mounting and the circuit board at the mounting destination will be adversely affected.
  • an object of the present invention is to provide a method for manufacturing a resistor whose resistance value can be adjusted while reducing changes in heat distribution, and a resistor.
  • a resistor comprising a resistor and a pair of electrodes connected to the resistor, and the resistance value can be adjusted by trimming a part of the resistor.
  • a recess is formed as a trimming in the resistor at the boundary between the resistor and the electrode.
  • FIG. 1 is a perspective view of the resistor of the present embodiment.
  • FIG. 2 is a perspective view of the resistor of the present embodiment as viewed from the mounting surface side on the circuit board.
  • FIG. 3 is a diagram showing a mounting surface of a resistor and is a diagram for explaining a recess.
  • FIG. 4 is a side view of the resistor shown in FIG. 3 and a diagram showing the heat distribution of the resistor.
  • FIG. 5 is a side view of a modified example of the recess.
  • FIG. 6 is a schematic view when a recess is formed in the resistor of the present embodiment.
  • FIG. 7 is a cross-sectional photograph of the resistor of the present embodiment solder-mounted.
  • FIG. 8 is a side view showing a modified example of the resistor of the present embodiment.
  • FIG. 9 is a plan view showing a modified example of the resistor of the present embodiment.
  • FIG. 10 is a schematic view illustrating a method for manufacturing a resistor according to the present embodiment.
  • FIG. 11 is a front view of the die used in the step (c) shown in FIG. 10 as viewed from the upstream side in the drawing direction F.
  • FIG. 12 is a cross-sectional view taken along the line BB of FIG. 11 and is a schematic view illustrating a step of processing a shape in the method for manufacturing a resistor according to the present embodiment.
  • FIG. 1 is a perspective view of the resistor 1 of the present embodiment.
  • FIG. 2 is a perspective view of the resistor 1 of the present embodiment as viewed from the mounting surface side on the circuit board.
  • the resistor 1 includes a resistor 10, a first electrode body 11 (electrode), and a second electrode body 12 (electrode), and the first electrode body 11, the resistor 10, and the second electrode body 12 are formed. It is joined in this order.
  • the resistor 1 is mounted on a circuit board or the like not shown in FIG.
  • the resistor 1 is arranged on a pair of electrodes formed on a land pattern of a circuit board.
  • the resistor 1 is used as a current detection resistor (shunt resistor).
  • the direction in which the first electrode body 11 and the second electrode body 12 are arranged is the X direction (the first electrode body 11 side is the + X direction, and the second electrode body 12 side is the second electrode body 12 side).
  • the width direction of the resistor 1 is the Y direction (the front side of the paper surface in FIG. 1 is the + Y direction, and the back side of the paper surface in FIG. 1 is the -Y direction).
  • the thickness direction of the resistor 1 is set to the Z direction (the direction toward the circuit board is the ⁇ Z direction, and the direction away from the circuit board is the + Z direction), and the X direction, the Y direction, and the Z direction are orthogonal to each other.
  • the mounting surface of the resistor 1 means a surface on which the resistor 1 faces the circuit board when the resistor 1 is mounted on the circuit board, and the first electrode body 11, the resistor 10, and the second electrode body. Includes a surface facing the 12 circuit boards.
  • the surface opposite to the mounting surface is referred to as the upper surface.
  • the resistor 10 is formed in a rectangular parallelepiped (or cubic) shape.
  • the resistor 10 it is possible to use a material having a low resistance to a high resistance according to the application.
  • the resistor 10 is preferably a resistor material having a small resistivity and a small temperature coefficient of resistance (TCR) from the viewpoint of accurately detecting a large current.
  • TCR temperature coefficient of resistance
  • copper / manganese / nickel alloys, copper / manganese / tin alloys, nickel / chromium alloys, copper / nickel alloys and the like can be used.
  • the first electrode body 11 includes a body portion 21 joined to the resistor body 10 and a leg portion 22 formed integrally with the body portion 21 and extending toward the circuit board.
  • the second electrode body 12 includes a body portion 31 joined to the resistor body 10 and a leg portion 32 formed integrally with the body portion 31 and extending toward the circuit board.
  • the first electrode body 11 (body portion 21, leg portion 22) and the second electrode body 12 (body portion 31, leg portion 32) have good electrical conductivity and thermal conductivity from the viewpoint of ensuring stable detection accuracy. It is preferably a conductive material.
  • copper, a copper-based alloy, or the like can be used as the first electrode body 11 and the second electrode body 12.
  • oxygen-free copper C1020
  • the same ones can be used.
  • the body portion 21 of the first electrode body 11 has an end face having substantially the same shape as the end face of the resistor 10 in the + X direction, and is joined to the end face of the resistor 10 so as to be abutted against the end face of the resistor 10 in the + X direction. ..
  • the joint portion 13 which is the boundary portion between the body portion 21 and the resistor portion 10
  • the boundary between the resistor portion 10 and the body portion 21 is flat without a step, and the resistor 10 and the body portion 21 are smoothly continuous. There is. That is, the surface of the joint portion 13 is formed flat (without a step) over the entire boundary between the resistor 10 and the body portion 21.
  • the body portion 31 of the second electrode body 12 has an end face having substantially the same shape as the end face of the resistor 10 in the ⁇ X direction, and is joined in such a manner that the end face is abutted with the end face of the resistor 10 in the ⁇ X direction. ing.
  • the joint portion 14 which is the boundary portion between the body portion 31 and the resistor portion 10
  • the boundary between the resistor portion 10 and the body portion 31 is flat without a step, and the resistor 10 and the body portion 31 are smoothly continuous.
  • the surface of the joint portion 14 is formed flat (without a step) over the entire boundary between the resistor 10 and the body portion 31.
  • the leg portion 22 is a member extending from the mounting surface of the resistor 1, that is, the circuit board side of the body portion 21 in the ⁇ Z direction.
  • the leg portion 22 has a shorter length in the X direction than the body portion 21, but the side surface in the + X direction forms the same plane as the side surface in the + X direction of the body portion 21.
  • the leg portion 32 is a member extending from the mounting surface of the resistor 1, that is, the circuit board side of the body portion 31 toward the ⁇ Z direction.
  • the leg portion 32 has a shorter length in the X direction than the body portion 31, but the side surface in the ⁇ X direction forms the same plane as the side surface in the ⁇ X direction of the body portion 31.
  • each of the bonding surfaces is a diffusion bonding surface in which the metal atoms of the resistor 10 and the first electrode body 11 are diffused with each other, and a diffusion bonding surface in which the metal atoms of the resistor 10 and the second electrode body 12 are diffused with each other. ing.
  • the resistor 1 is mounted on the circuit board so that the legs 22 and 32 project toward the circuit board, so that the resistor 10 is mounted on the circuit board in a state of being separated from the circuit board.
  • the portion protruding from the body portion 21 in the ⁇ X direction is the protruding portion 211, and the protruding portion 211 is joined to the resistor 10.
  • the portion protruding from the body portion 31 toward the + X direction is the protruding portion 311, and the protruding portion 311 is joined to the resistor 10.
  • the length L (see FIG. 1) in the longitudinal direction (X direction) of the resistor 1 is constant, the length L1 (length of the body portion 21, see FIG. 1) of the protruding portion 211 in the X direction, or the protrusion.
  • the length L0 of the resistor 10 in the longitudinal direction (X direction) of the resistor 10 the length L1 of the first electrode body 11 in the X direction, and the length L2 of the second electrode body 12 in the X direction.
  • the resistor 1 has a streak-like unevenness 15 (see the enlarged view of FIG. 1 and the enlarged view of FIG. 2) on the surface.
  • the streak-like unevenness 15 is formed so as to extend along the Y direction on the side surface of the resistor 1 facing the + Y direction and the side surface other than the side surface facing the ⁇ Y direction.
  • the surface roughness due to the concave and convex portions of the streak-like unevenness 15 can be 0.2 to 0.3 ⁇ m in arithmetic average roughness (Ra).
  • the length L of the resistor 1 in the X direction is formed to be 3.2 mm or less. Further, the resistance value of the resistor 1 is adjusted to be 2 m ⁇ or less.
  • the length L of the resistor 1 in the X direction is 3.2 mm or less
  • the length (width) W of the resistor 1 in the Y direction is 1.6 mm.
  • the following (product standard 3216 size) can be used. Therefore, as the size of the resistor 1 of the present embodiment, the product standard 2012 size (L: 2.0 mm, W: 1.2 mm), the product standard 1608 size (L: 1.6 mm, W: 0.8 mm), It is also applicable to product standard 1005 size (L: 1.0 mm, W: 0.5 mm).
  • the length L of the resistor 1 of the present embodiment is the above-mentioned product standard from the viewpoint of handleability in the manufacturing method described later, for example, prevention of breakage of the resistor base material 100 (see FIG. 14) which is the base of the resistor 1.
  • the size can be 1005 or more.
  • the resistance value of the resistor 1 can be adjusted to be 2 m ⁇ or less in any of the above sizes from the viewpoint of realizing small size and low resistance, for example, 0.5 m ⁇ or less. It is adjustable.
  • the low resistance here is a concept including a resistance value lower than the resistance value assumed from the dimensions of a general resistor (for example, a resistor of the type of JP-A-2002-57009).
  • the corner portions P which are the edges extending in the Y direction of the resistor 1, all have a chamfered shape.
  • the mounting surface side of the resistor 1 of the present embodiment (not only the mounting surface but also the side surface of the resistor 1 facing the Y direction and including a region near the mounting surface).
  • a recess 6 is formed in the hole.
  • the recess 6 is formed to adjust the resistance value of the resistor 1.
  • the recess 6 is formed along the joint portion 13 and the joint portion 14 on the mounting surface side of the resistor 1. This will be described later with reference to FIGS. 3 to 5.
  • FIG. 3 is a diagram showing a mounting surface of the resistor 1 and is a diagram for explaining the recess 6.
  • FIG. 4 is a side view of the resistor 1 shown in FIG. 3 and a diagram showing the heat distribution of the resistor 1.
  • FIG. 5 is a side view of a modified example of the recess 6.
  • the recess 6 (6a) is arranged so as to straddle the joint portion 13 on the mounting surface side of the resistor 1, and the resistor 10 and the first electrode body 11 extend in the Y direction. Is formed in.
  • the recess 6 (6b) is arranged so as to straddle the joint portion 14 on the mounting surface side of the resistor 1, and is formed in the resistor 10 and the second electrode body 12 so as to extend in the Y direction.
  • the + Y-direction end of the recess 6 (6a, 6b) is open to the side surface of the resistor 1 facing the + Y direction
  • the ⁇ Y-direction end of the recess 6 (6a, 6b) is the resistor 1. It is open to the side surface facing the ⁇ Y direction of.
  • the recesses 6 (6a, 6b) are groove-shaped recesses, and the cross section seen from the Y direction is substantially semicircular (or rectangular, amorphous).
  • the recess 6 (6c, 6d) as a modification is formed so as to extend the resistor 1 in the Y direction like the recess 6 (6a, 6b) shown in FIGS. 4 and 5. However, all of them are formed so as to be grooved in the Y direction in the region of only the resistor 10.
  • the end portion of the recess 6 (6c) in the + X direction overlaps with the joint portion 13.
  • the end portion of the recess 6 (6d) in the ⁇ X direction overlaps with the joint portion 14.
  • the cross section of the recess 6 (6c, 6d) seen from the Y direction is also substantially semicircular (or rectangular, amorphous).
  • the heat distribution of the resistor 1 when the current is supplied is as shown in FIG. That is, the maximum temperature is the highest in the central portion of the resistor 10 in the X direction, and the temperature gradient is inclined to the low temperature side while the temperature is lowered each time the resistor 10 is separated from the central portion in the X direction. After that, the heat distribution reaches the inflection point (inflection point a, inflection point b) where the temperature gradient becomes maximum, and then the temperature decreases as the temperature approaches the electrode, but the temperature gradient becomes smaller.
  • the resistance value is generally adjusted in such a manner that the resistance value is shifted to the high resistance side by cutting (trimming) a part of the resistor 10.
  • a part of the resistor 10 is cut off at the center of the resistor 10 in the X direction and its vicinity, or at the above-mentioned inflection point and its vicinity, the heat distribution of the entire resistor 10 is designed. There is a risk of significant changes from the heat distribution.
  • the resistor 10 when electric power is applied to the resistor 1, the resistor 10 generates heat, but the central portion of the resistor 10 in the longitudinal direction (X direction) has the highest temperature, and the characteristic of the central portion is the heat distribution of the entire resistor 1. Has the greatest impact on.
  • the heat distribution of the resistor 1 changes significantly. Therefore, when a resistor including such a resistor 10 is mounted on a circuit board and used, not only the resistor 1 but also the heat distribution of the circuit board changes from the design heat distribution, and the resistor and the circuit board have the same heat distribution. There is a risk of adverse effects.
  • the recesses 6 (6a, 6c), which are trimming marks are located near the joint portion 13 in the resistor 10, that is, the first electrode is located at the inflection point a. It is formed on the body 11 side.
  • the recesses 6 (6b, 6d), which are trimming marks are formed in the resistor 10 in the vicinity of the joint portion 14, that is, on the second electrode body 12 side of the above-mentioned inflection point b. This makes it possible to adjust the resistance value while suppressing changes in the heat distribution.
  • trimming is performed by irradiating at least the resistor 10 (and the first electrode body 11 and the second electrode body 12) with a laser, and a recess 6 is formed as a trimming mark thereof.
  • a recess 6 is formed by this method, an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the periphery thereof.
  • the oxide film is a thermal oxide film formed by irradiating the surface of any one of the resistor 10, the first electrode body 11, and the second electrode body 12 with a laser and heating the surface. It is known that this oxide film has low wettability with respect to solder.
  • the resistor 1 of the present embodiment is mounted on the circuit board by the reflow process, and at that time, the solder easily crawls up the legs 22 and 32.
  • the recess 6 extends in the Y direction and opens the side surface of the resistor 1 facing the + Y direction and the side surface facing the ⁇ Y direction of the resistor 10 (and). It is formed in the first electrode body 11 and the second electrode body 12).
  • the oxide film can block the path through which the solder that has crawled up the legs 22 and 32 in the reflow process climbs up to the resistor 10. Therefore, it is possible to prevent the solder from coming into contact with the resistor 10 in the reflow process, and to avoid a decrease in current detection accuracy using the resistor 1.
  • the solder that crawls up the leg 22 is the resistor 10 from the joint position (joint 13) of the first electrode body 11 on the mounting surface with the resistor 10. Crawling to the side (-X direction side) is prevented. Then, the solder that crawls up the leg portion 32 prevents the solder that crawls up from the joint position (joint portion 14) of the second electrode body 12 of the mounting surface to the resistor 10 to the resistor 10 side ( ⁇ X direction side). Will be done.
  • FIG. 6 is a schematic view in the case where the recess 6 is formed in the resistor 1 of the present embodiment.
  • a recess 6 is formed as a trimming mark, and an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the periphery thereof. Is formed. Therefore, in the trimming by laser irradiation, the resistance value can be adjusted and the solder can be prevented from creeping up at the same time.
  • the laser is irradiated to a predetermined range including the joint portion 13 and a predetermined range including the joint portion 14 on the mounting surface side of the resistor 1.
  • the resistor 1 of the present embodiment is clad-bonded (solid-phase bonded) with the resistor base material 10A sandwiched between the electrode body base materials 11A and 12A. It is formed by inserting the resistor base material 100 into the die 300 to reduce the cross-sectional area, transforming the cross-sectional shape into the cross-sectional shape of the resistor 1, and cutting the resistor base material 100 after being inserted into the die 300. .. Therefore, the joint portion 13 (boundary portion) and the joint portion 14 (boundary portion) are usually flat surfaces (straight lines), but may meander slightly. In this case, it is difficult to irradiate the laser only at the joint portion 13 and the joint portion 14.
  • the resistor 10 and the first electrode body 11 are irradiated with the laser at the joint portion 13.
  • the laser is, for example, + Y from a position at the end of the irradiation area 51 in the ⁇ X direction and separated from the resistor 1 in a plan view. It moves in the direction, irradiates the resistor 1, and moves to a position away from the resistor 1 in a plan view. After that, the laser moves slightly in the + X direction (the amount of movement is smaller than the spot diameter on the resistor 1 of the laser), moves in the ⁇ Y direction, irradiates the resistor 1 and irradiates the resistor 1 in a plan view. Move to a position away from. After that, the same operation is repeated to irradiate the entire irradiation area 51 with the laser.
  • the laser may not be stable because its output becomes excessive or too small immediately after oscillation. Therefore, as described above, it is possible to start oscillating the laser from a position separated from the resistor 1 in a plan view (a position where the laser is not irradiated to the resistor 1) and irradiate the resistor 1 with a laser having a stable output. desirable.
  • the resistance value is not stable. Therefore, the resistance value is measured after the laser irradiation, and the laser irradiation and the measurement of the resistance value are alternately performed until the resistance value reaches the desired resistance value. You can repeat it.
  • FIG. 7 is a cross-sectional photograph of the resistor 1 of the present embodiment solder-mounted.
  • the resistor 1 shown in FIG. 7 is formed by clad bonding by abutting the end face of the resistor 10 and the end face of the first electrode body 11 and abutting the end face of the resistor 10 and the end face of the second electrode body 12 in the same manner as described above. It was done.
  • an oxide film is formed at the boundary portion straddling the joint portion 14 between the second electrode body 12 and the resistor 10, but the first electrode body 11 and the resistor 10 are formed. No oxide film is formed at the boundary portion straddling the joint portion 13.
  • the resistor 1 was mounted on the circuit board 7 via the solder 9 by the reflow process.
  • the solder 9 that has come into contact with the leg portion 22 of the first electrode body 11 on the right side crawls up the leg portion 22, crawls up to the resistor 10 via the protrusion 211 on the mounting surface, and contacts the resistor 10. It is in a state of being.
  • the solder 9 in contact with the leg portion 32 of the second electrode body 12 crawls up the leg portion 32 and crawls up to the protruding portion 311 on the mounting surface, but the crawl up is prevented at a position in contact with the oxide film. ..
  • the boundary portion straddling the joint portion 14 between the second electrode body 12 and the resistor 10 and the boundary portion straddling the joint portion 13 between the first electrode body 11 and the resistor 10 are oxidized.
  • Each of the recesses 6 having a film is formed. It can be easily understood that this makes it possible to prevent the solder 9 from climbing up to the resistor 10.
  • FIG. 8 is a side view showing a modified example of the resistor 1 of the present embodiment.
  • FIG. 9 is a plan view showing a modified example of the resistor 1 of the present embodiment.
  • the leg portion 22 of the first electrode body 11 and the leg portion 32 of the second electrode body 12 are not provided, and the mounting surface of the resistor 1 is flat.
  • the electrodes 71 and 72 are arranged on the circuit board 7, and the electrodes 71 and 72 are arranged so as to project from the circuit board 7.
  • the first electrode body 11 is mounted on the electrode 71 by solder (not shown), and the second electrode body 12 is mounted on the electrode 72 by solder (not shown).
  • the resistor 10 is arranged slightly separated from the circuit board 7.
  • a recess 6 (6e) is formed so as to straddle the joint portion 13
  • a recess 6 (6f) is formed so as to straddle the joint portion 14.
  • the recesses 6 (6e, 6f) extend in the Y direction by laser irradiation as described above, and resist so as to open the side surface of the resistor 1 facing the + Y direction and the side surface of the resistor 1 facing the ⁇ Y direction. It is formed in the vessel 1, and an oxide film is formed on the inner wall and its periphery.
  • the reflow step it is possible to prevent the solder that has crawled up the first electrode body 11 from crawling up to the resistor 10 beyond the recess 6 (6e) (oxide film) formed in the joint portion 13. Further, it is possible to prevent the solder crawling up on the second electrode body 12 from crawling up to the resistor 10 beyond the recess 6 (6f) (oxide film) formed in the joint portion 14.
  • a recess 6 (6 g) is formed so as to straddle the joint portion 13
  • a recess 6 (6 h) is formed so as to straddle the joint portion 14.
  • the recesses 6 (6 g) are formed at both ends in the Y direction (may be other places) in a manner of trimming a part of the joint portion 13 on the upper surface.
  • the recesses 6 (6h) are formed at both ends in the Y direction (may be other places) in a manner of trimming a part of the joint portion 14 on the upper surface.
  • the recess 6 (6g, 6h) is formed to adjust the resistance value. Therefore, the recesses 6 (6g, 6h) need not be formed on the upper surface of the resistor 1 in a manner that reaches from end to end in the Y direction, and the inner wall may not have an oxide film.
  • the recess 6 (6g, 6h) is an effective component when the resistance value is not sufficiently adjusted only by the recess 6 (6e, 6f) formed on the mounting surface side.
  • the recess 6 (6 g) may be formed at a position on the side surface of the resistor 1 in the + Y direction and / or the side surface in the ⁇ Y direction and overlapping the joint portion 13.
  • the recess 6 (6h) may be formed at a position on the side surface of the resistor 1 in the + Y direction and / or the side surface in the ⁇ Y direction and overlapping the joint portion 14.
  • the recesses 6 (6a, 6b, 6c, 6d, 6e, 6f) formed on the mounting surface side can be formed without an oxide film.
  • the opening 301 (outlet opening 303) It can also be formed by inserting the resistor base material 100 into the opening 301 with a shape that follows the outer shape of the recess 6 added to the recess 6.
  • the resistor 10 includes a resistor 10 and a pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10.
  • This is a method for manufacturing a resistor 1 whose resistance value can be adjusted by trimming a part of the resistor 1, and is a boundary portion (joint portion) between the resistor 10 and an electrode (first electrode body 11, second electrode body 12).
  • a recess 6 is formed in the resistor 10 at the joint portion 14) as a trimming.
  • the resistor 10 generates heat when a current is applied, but the resistor 10 has a boundary portion (joint portion 13, joint portion 14) between the resistor 10 and the electrodes (first electrode body 11, second electrode body 12). Is the lowest temperature. Therefore, by forming the recess 6 as a trimming in the boundary portion (joint portion 13, joint portion 14), the resistance value can be adjusted while reducing the change in the heat distribution of the resistor 1.
  • the recess 6 when the recess 6 is mounted on the substrate (circuit board) with the resistor 10 and the pair of electrodes (first electrode body 11, second electrode body 12) both facing the substrate (circuit board). It is formed on the mounting surface of the resistor 1 of. As a result, the recess 6 is not formed on the opposite surface (upper surface) of the resistor 1 on the mounting surface side, and the opposite surface can maintain flatness. Therefore, when the resistor 1 is mounted, the resistor 1 is subjected to negative pressure. This makes it possible to secure the adsorptivity of the nozzle that sucks and holds.
  • the recess 6 when the recess 6 is formed by laser irradiation, an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the peripheral edge thereof, and the oxide film can prevent the solder from creeping up during mounting. Therefore, it is possible to prevent the resistor 10 from coming into contact with the solder and avoid a decrease in detection accuracy in the current measurement using the resistor 1.
  • the electrodes project from the body portions 21 and 31 connected to the resistor 10 and the body portions 21 and 31 toward the substrate (circuit board). It has legs 22 and 32.
  • the oxide film is formed in the recess 6, it is possible to prevent the solder from creeping up to the resistor 10 while ensuring the bonding between the legs 22 and 32 and the solder.
  • the resistor 10 and the electrodes are joined so that their end faces are abutted against each other.
  • a small and low resistance resistor 1 can be realized because it is composed of a pair of electrodes (first electrode body 11, second electrode body 12) that sandwich the resistor 10 and the resistor 10.
  • the recess 6 is formed from the resistor 10 to the electrodes (first electrode body 11, second electrode body 12). Thereby, trimming can be performed stably.
  • a resistor 10 and a pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10 are provided, and a part of the resistor 10 is provided. It is a resistor 1 whose resistance value can be adjusted by trimming the resistor 1, and is a boundary portion (joint portion 13, joint portion 14) between the resistor 10 and an electrode (first electrode body 11, second electrode body 12).
  • a recess 6 is formed in the resistor 10 as trimming, and the recess 6 is formed by laser irradiation.
  • the resistor 10 generates heat when a current is applied, but the resistor 10 has a boundary portion (joint portion 13, joint portion 14) between the resistor 10 and the electrodes (first electrode body 11, second electrode body 12). Is the lowest temperature. Therefore, by forming the recess 6 as a trimming in the boundary portion (joint portion 13, joint portion 14), the resistance value can be adjusted while reducing the change in the heat distribution of the resistor 1. Further, when the recess 6 is formed by laser irradiation, an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the peripheral edge thereof, and the oxide film can prevent the solder from creeping up during mounting. Therefore, it is possible to prevent the resistor 10 from coming into contact with the solder and avoid a decrease in detection accuracy in the current measurement using the resistor 1.
  • the resistor 1 of the present embodiment has the following configurations, actions, and effects.
  • the resistor 1 includes the resistor 10 and a pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10.
  • the end face of the resistor 10 and the end face of the electrode (first electrode body 11, second electrode body 12) are butted and joined, and the electrode (first electrode body 11, second electrode body 12) is a body portion.
  • the length dimension of the long side of the resistor 1 is 3.2 mm or less, and the resistance value is 2 m ⁇ or less. be.
  • the resistor 10 and the pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10 constitute legs 22 and 32 protruding from the body portions 21 and 31 to the mounting surface. Will be done.
  • the resistor 1 can be realized because it can be pulled out from the detection terminal between the legs 22 and 23.
  • electrodes (first electrode body 11, second electrode body 12) are joined to both ends of the resistor 10, and the dimensions (in the X direction) of the resistor 10 are (in the X direction) of the resistor 1. It is smaller than the dimension. Therefore, it is possible to realize a resistor 1 having a lower resistance than a type of resistor in which a pair of electrodes are bonded to the lower surface of the resistor 10. From the above, it becomes a resistor 1 that can realize a smaller resistance (2 m ⁇ or less) that is not found in general resistors while realizing miniaturization (long side dimension 3.2 mm or less, 3216 size or less).
  • the resistor is formed by welding the resistor and the electrode body with an electron beam or the like, it is necessary to consider the influence of the bead due to the welding on the resistance value at this size.
  • the resistor 10 and the first electrode body 11 and the resistor 10 and the second electrode body 12 can be joined by diffusion bonding, respectively. Even if it is designed to be compact, characteristics such as resistance can be stabilized.
  • the boundary portion (joint portion 13, 14) between the resistor 10 and the body portions 21, 31 is flat.
  • the boundary between the resistor 10 and the body portions 21 and 31 becomes clear, and a good or bad judgment can be easily performed.
  • the resistor 1 is used as a shunt resistor, it is possible to suppress a decrease in the detection accuracy of the current generated due to a step at the boundary (joint portions 13 and 14) between the resistor 10 and the body portions 21 and 31. .. Further, the stability of resistance value and thermal characteristics can be improved.
  • the resistor 10 and the body portions 21 and 31 are joined by solid phase bonding.
  • the resistor 10 and the first electrode body 11 and the resistor 10 and the second electrode body 12 are firmly bonded to each other, so that good electrical characteristics can be obtained.
  • welding such as an electron beam is not used for joining the resistor 10 and the first electrode body 11 and the resistor 10 and the second electrode body 12, the joining portions 13 and 14 are joined. Has no welding beads (welded marks with uneven shape). Therefore, the bondability is not impaired when wire bonding or the like is applied to the surface of the resistor 1.
  • the body portions 21 and 31 have protruding portions 211 and 311 protruding toward the resistor 10.
  • the length L of the resistor 1 in the longitudinal direction (X direction) is constant, the length L1 of the protruding portion 211 in the X direction (the length of the body portion 21) or the length L of the protruding portion 311 in the X direction
  • the ends of the legs 22 and 32 on the mounting surface side in the arrangement direction (X direction) of the resistor 10 of the resistor 1 and the electrodes (first electrode body 11, second electrode body 12) are chamfered. It has a shape.
  • the corner portion P is chamfered, the bias of the current density in the corner portion P is alleviated. As a result, the occurrence of electromigration can be suppressed. Similarly, since the thermal stress concentration can be relaxed, the heat cycle resistance can be improved.
  • the alignment direction (X direction) of the resistor 10 and the electrodes (first electrode body 11, second electrode body 12) of the resistor 1 and the direction perpendicular to the mounting direction of the resistor 1 (Z direction) are set.
  • the width direction (Y direction) the surface of the resistor 10 and / or the surface of the electrodes (first electrode body 11, second electrode body 12) has streaky irregularities extending along the width direction (Y direction).
  • a surface (streak-like unevenness 15) is formed.
  • the surface area of the resistor 1 can be increased to improve heat dissipation, and when formed on the electrodes (first electrode body 11, second electrode body 12), solder for fixing the resistor 1 to the circuit board. It is possible to increase the joint strength of.
  • the resistor 10 is formed in a rectangular parallelepiped (or a cube).
  • the resistor 10 is formed from the first electrode body 11 and the second electrode body 12 which are formed in substantially the same shape as the end face of the resistor 10 and are joined to the end face of the resistor 10. Since the path of the current flowing through the is linear, the resistance value can be stabilized. Further, in the resistor 1, since the resistor 10 is joined between the first electrode body 11 and the second electrode body 12, the resistance value can be adjusted by minimizing the volume of the resistor 10. Is.
  • FIG. 10 is a schematic view illustrating a method for manufacturing the resistor 1 of the present embodiment.
  • the method for manufacturing the resistor 1 of the present embodiment includes a step of preparing the material (a), a step of joining the materials (b), a step of processing the shape (c), and cutting into individual resistors 1 ( It includes a step (d) of individualizing) and a step (e) of adjusting the resistance value of the resistor 1 using a laser.
  • the resistor base material 10A and the electrode body base materials 11A and 12A are prepared.
  • a copper / manganese / tin alloy or a copper / manganese / nickel alloy is used as the material of the resistor base material 10A (resistor 10) from the viewpoint of the size, resistance value and workability of the resistor 1.
  • oxygen-free copper C1020
  • the material of the electrode body base materials 11A and 12A first electrode body 11, second electrode body 12.
  • the electrode body base material 11A, the resistor base material 10A, and the electrode body base material 12A are stacked in this order, and pressure is applied in the stacking direction to join the resistor base material 100. To form.
  • step (b) so-called clad bonding (solid phase bonding) between dissimilar metal materials is performed.
  • the joint surface between the electrode body base material 11A and the resistor base material 10A that have been clad-bonded, and the joint surface between the electrode body base material 12A and the resistor base material 10A are the diffusion joint surfaces in which both metal atoms are diffused from each other. It has become.
  • the joint surface between the resistor base material 10A and the electrode body base material 11A and the joint surface between the resistor base material 10A and the electrode body base material 12A can be brought into contact with each other without welding with a general electron beam or the like. Can be firmly joined. Further, the joint surface between the resistor base material 10A (resistor 10) and the electrode body base material 11A (first electrode body 11) and the resistor base material 10A (resistor body 10) and the electrode body base material 12A (second electrode) Good electrical characteristics can be obtained at the joint surface with the body 12).
  • FIG. 11 is a schematic diagram illustrating a step (c) of processing a shape in the manufacturing method of the resistor 1 of the present embodiment.
  • the die 300 is used in the step (c).
  • the resistor base material 100 obtained by clad bonding is passed through the die 300.
  • An opening 301 is formed in the die 300.
  • the opening 301 has an inlet opening 302 set to a size into which the resistor base material 100 can be inserted, an outlet opening 303 set to a size smaller than the external dimension of the resistor base material 100, and an outlet from the inlet opening 302. It has an insertion portion 304 formed in a tapered shape toward the opening 303.
  • the resistor base material 100 By passing the resistor base material 100 through the die 300 having such a shape, the resistor base material 100 can be compressed and deformed from all directions. As a result, the cross-sectional shape of the resistor base material 100 becomes a shape that follows the outer shape of the die 300 (outlet opening 303).
  • the pull-out method is applied in which the resistor base material 100 is pulled out by the gripping tool 400.
  • a plurality of dies 300 having different sizes of the openings 301 may be prepared and subjected to a drawing process in which the plurality of dies 300 are passed in stages.
  • the resistor 1 of the present embodiment can be manufactured by changing the shape of the opening 301 of the die 300.
  • a die 300 having a shape protruding rectangularly toward the center of the opening is applied to a part of one side of the opening 301 (inlet opening 302, outlet opening 303). ..
  • a rectangular groove 105 continuous in the pulling direction is formed by the protruding shape provided in the rectangular outlet opening 303.
  • the rectangular groove 105 forms the body portion 21 and the leg portion 22 of the resistor 10 and the first electrode body 11, and the body portion 31 and the leg portion 32 of the second electrode body 12. Consists of a recess surrounded by.
  • the resistor 1 is cut out from the resistor base material 100 so as to have the designed length W in the Y direction. Further, in the present embodiment, in the step (d), from the surface 100a (mounting surface of the resistor 1) on which the rectangular groove 105 is formed in the resistor base material 100 to the opposite surface 100b (upper surface of the resistor 1). It is preferable to cut. As a result, the metal burr is formed so as to extend upward from the upper surface of the resistor 1, and the burr (toward the circuit board) extending in the ⁇ Z direction (FIGS. 1 and 2) at the legs 22 and 32. Burrs that extend) do not occur. As a result, the resistor 1 can be reliably mounted on the circuit board.
  • a piece of resistor 1 can be obtained from the resistor base material 100.
  • the resistor 10 is trimmed by laser irradiation to set the resistance value of the resistor 1 to a desired resistance value. The details of trimming are as described above (see FIGS. 8 to 10).
  • the corner portion P shown in FIGS. It is a streak-like sliding mark formed when sliding in a state.
  • the electrode body base material 11A, the resistor base material 10A, and the electrode body base material 12A are overlapped and pressure is applied to perform clad bonding (solid phase). It is integrated by joining).
  • the bonding strength between the resistor base material 10A (resistor 10) and the electrode body base material 11A (first electrode body 11) and the resistor base material 10A (resistor body 10) can be achieved without using welding with an electron beam or the like.
  • the electrode body base material 12A (second electrode body 12) can be increased.
  • the outer shape of the resistor base material 100 can be molded by passing the resistor base material 100 through the die 300 and compressing it from all directions. Therefore, after the resistor base material 100 is formed, the individual resistor 1 can be manufactured only by going through the step (d). Therefore, individual differences caused by the manufacture of the resistor 1 can be suppressed.
  • the bonding strength between the resistor 10 and the first electrode body 11 and the bonding strength between the resistor 10 and the second electrode body 12 are further increased. Can be enhanced.
  • the first stage is performed by a pair of rollers that pressurize the resistor base material 100 from the thickness direction (Z).
  • pressure welding is performed and then pressure welding is performed in the second stage by a pair of rollers that pressurize from the width direction (Y).
  • the resistor base material 100 in the first-stage pressure welding step, is compressed in the thickness direction Z, but expands in the width direction (Y). Further, in the subsequent pressure welding step of the second stage, the resistor base material 100 is compressed in the width direction Y, but expands in the thickness direction (Z). As a result, the dimensional accuracy is lowered, and the variation of individual resistors and the variation of temperature distribution when power is applied to the resistors become large.
  • the resistor base material 100 is pulled out through the die 300 to allow the resistor base material 100 to pass in the length direction (X) and the thickness direction (X). It can be uniformly compressed to Z).
  • the resistor base material 100 forms an electrically advantageous bonding interface as compared with the resistor base material obtained by repeating compression from one direction and compression from the other direction using a roller. It is thought that it will be done. Therefore, it is possible to suppress the characteristic difference of the resistor 1 as a finished product.
  • a plurality of dies 300 having different openings 301 are used stepwise, and the size of the resistor base material 100 is compression-molded so as to be stepwise reduced. While reducing the load on the base material 100 and the die 300, the resistor base material 100 can be uniformly compressed in the length direction (X) and the thickness direction (Z). As a result, it is possible to suppress variations in the characteristics of the resistor 1 as a finished product.
  • the accuracy of the finished product is improved as compared with the extrusion method by applying the drawing step in the step (c) of passing the resistor base material 100 through the die 300.
  • this manufacturing method it is possible to realize stabilization of the characteristics of the resistor 1.
  • At least the outlet opening 303 of the opening 301 of the die 300 is continuously formed by a curved line.
  • the corner portion of the resistor 1 obtained by passing through the die 300 is chamfered. As a result, the electromigration that occurs in the resistor 1 at the corner portion P can be suppressed. In addition, the heat cycle resistance of the resistor 1 can be increased.
  • the resistor 10 and the second electrode body 12 are bonded to each other by diffusion bonding (solid phase bonding), there is no welding bead.
  • the welding bead may have a non-negligible effect on the resistance value characteristics as the resistor becomes smaller.
  • the resistor 1 obtained by the above-mentioned manufacturing method of the present embodiment does not have such a concern.
  • the resistor base material 100 obtained by clad bonding (solid phase bonding) the resistor base material 10A and the electrode body base materials 11A and 12A is passed through a die 300 and molded. do. Therefore, it is possible to increase the bonding strength between materials without using welding with an electron beam or the like, and it is possible to secure high dimensional accuracy, which is suitable for manufacturing a small resistor 1.
  • the resistor base material 100 In manufacturing the resistor 1, in the step (d), it is preferable to cut the resistor base material 100 from the surface 100a on which the rectangular groove 105 is formed toward the opposite surface 100b. As a result, burrs generated by cutting can be accommodated in the space of the groove (recess) on the mounting surface side.
  • a step of adjusting the size of the clad-bonded resistor base material 100 to a size that can be inserted into the die 300 is included in the first stage of the step (c) of processing the shape. You may.
  • laser irradiation is used for forming an oxide film, but the present invention is not limited to a laser as long as an oxide film having a modified metal surface can be formed, and for example, an oxidizing agent is supplied. As a result, an oxide film may be formed.
  • the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. do not have.
  • the resistor 1 in which the resistor base material 100 is passed through the die 300 and separated into individual pieces has been described, but a resistor in which the resistor and the electrode body are clad-bonded without passing through the die 300, or a press. It can also be applied to resistors molded by processing.
  • the resistor 10 is a rectangular parallelepiped, but may have a trapezoidal shape in which the length in the X direction (see FIG. 1) becomes shorter toward the + Z direction (see FIG. 1). Further, the present embodiment can also be applied to a resistor in which electrodes are joined to both ends in the X direction on the mounting surface of the resistor 10, for example.
  • the recesses 6 are formed in pairs between the pair of electrodes, but in the X direction. It may be formed in the vicinity of the electrodes so as to be symmetrical with each other. Further, the recess 6 (6a-6f) does not have to be formed so as to reach from end to end in the Y direction. Even in this case, the change in heat distribution can be suppressed.

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Abstract

A manufacturing method for a resistor 1 that comprises a resistance body 10 and a pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistance body 10, and in which the resistance value can be adjusted by trimming a section of the resistance body 10. In this manufacturing method, the resistance body 10 is trimmed at the boundary sites (junction section 13, junction section 14) of the resistance body 10 and the electrodes (first electrode body 11, second electrode body 12), and recesses 6 are formed.

Description

抵抗器の製造方法、及び抵抗器How to manufacture a resistor and a resistor
　本発明は、抵抗器の製造方法、及び抵抗器に関する。 The present invention relates to a method for manufacturing a resistor and a resistor.
　ＪＰ２００９－０７１１２３Ａは、電流検出用の抵抗器として、抵抗体の両端面に一対の電極を溶接した抵抗器を開示している。 JP2009-071123A discloses a resistor in which a pair of electrodes are welded to both end faces of the resistor as a resistor for current detection.
　ＪＰ２００９－０７１１２３Ａに係るタイプの抵抗器では、抵抗体の一部にトリミングを行うことにより抵抗値の調整を行うが、抵抗体において任意の位置でトリミングを行うと、抵抗体の熱分布が設計上の熱分布とは異なるものとなり、実装後の抵抗器及び実装先の回路基板に悪影響を及ぼす虞があった。 In the type of resistor related to JP2009-071123A, the resistance value is adjusted by trimming a part of the resistor, but when trimming is performed at an arbitrary position on the resistor, the heat distribution of the resistor is designed. The heat distribution will be different from that of the above, and there is a risk that the resistor after mounting and the circuit board at the mounting destination will be adversely affected.
　そこで本発明は、熱分布の変化を低減しつつ抵抗値の調整が可能な抵抗器の製造方法、及び抵抗器を提供することを目的とする。 Therefore, an object of the present invention is to provide a method for manufacturing a resistor whose resistance value can be adjusted while reducing changes in heat distribution, and a resistor.
　本発明の１つの態様によれば、抵抗体と、抵抗体に接続された一対の電極と、を備え、抵抗体の一部にトリミングを行うことにより抵抗値の調整が可能な抵抗器の製造方法であって、抵抗体と電極の境界部位における抵抗体にトリミングとして凹部を形成する。 According to one aspect of the present invention, there is a resistor comprising a resistor and a pair of electrodes connected to the resistor, and the resistance value can be adjusted by trimming a part of the resistor. In this method, a recess is formed as a trimming in the resistor at the boundary between the resistor and the electrode.
図１は、本実施形態の抵抗器の斜視図である。FIG. 1 is a perspective view of the resistor of the present embodiment. 図２は、本実施形態の抵抗器を回路基板への実装面側から見た斜視図である。FIG. 2 is a perspective view of the resistor of the present embodiment as viewed from the mounting surface side on the circuit board. 図３は、抵抗器の実装面を示す図であって凹部を説明するための図である。FIG. 3 is a diagram showing a mounting surface of a resistor and is a diagram for explaining a recess. 図４は、図３に示す抵抗器の側面図、及び抵抗器の熱分布を示す図である。FIG. 4 is a side view of the resistor shown in FIG. 3 and a diagram showing the heat distribution of the resistor. 図５は、凹部の変形例の側面図である。FIG. 5 is a side view of a modified example of the recess. 図６は、本実施形態の抵抗器に凹部を形成する場合の模式図である。FIG. 6 is a schematic view when a recess is formed in the resistor of the present embodiment. 図７は、本実施形態の抵抗器を半田実装したときの断面写真である。FIG. 7 is a cross-sectional photograph of the resistor of the present embodiment solder-mounted. 図８は、本実施形態の抵抗器の変形例を示す側面図である。FIG. 8 is a side view showing a modified example of the resistor of the present embodiment. 図９は、本実施形態の抵抗器の変形例を示す平面図である。FIG. 9 is a plan view showing a modified example of the resistor of the present embodiment. 図１０は、本実施形態の抵抗器の製造方法を説明する模式図である。FIG. 10 is a schematic view illustrating a method for manufacturing a resistor according to the present embodiment. 図１１は、図１０に示す工程（ｃ）に用いられるダイスを引き抜き方向Ｆの上流側から見た正面図である。FIG. 11 is a front view of the die used in the step (c) shown in FIG. 10 as viewed from the upstream side in the drawing direction F. 図１２は、図１１のＢ－Ｂ線断面図であって、本実施形態の抵抗器の製造方法における形状を加工する工程を説明する模式図である。FIG. 12 is a cross-sectional view taken along the line BB of FIG. 11 and is a schematic view illustrating a step of processing a shape in the method for manufacturing a resistor according to the present embodiment.
　［抵抗器の説明］
　本発明の本実施形態の抵抗器１について、図１、図２を用いて詳細に説明する。図１は、本実施形態の抵抗器１の斜視図である。図２は、本実施形態の抵抗器１を回路基板への実装面側から見た斜視図である。 [Description of resistor]
The resistor 1 of the present embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the resistor 1 of the present embodiment. FIG. 2 is a perspective view of the resistor 1 of the present embodiment as viewed from the mounting surface side on the circuit board.
　抵抗器１は、抵抗体１０と、第１電極体１１（電極）と、第２電極体１２（電極）とを備え、第１電極体１１と抵抗体１０と第２電極体１２とが、この順に接合されたものである。抵抗器１は、図１には示されていない回路基板等に実装される。例えば、抵抗器１は、回路基板のランドパターン上に形成された一対の電極の上に配置される。本実施形態では、抵抗器１は、電流検出用抵抗器（シャント抵抗器）として用いられる。 The resistor 1 includes a resistor 10, a first electrode body 11 (electrode), and a second electrode body 12 (electrode), and the first electrode body 11, the resistor 10, and the second electrode body 12 are formed. It is joined in this order. The resistor 1 is mounted on a circuit board or the like not shown in FIG. For example, the resistor 1 is arranged on a pair of electrodes formed on a land pattern of a circuit board. In this embodiment, the resistor 1 is used as a current detection resistor (shunt resistor).
　なお、本実施形態では、第１電極体１１と第２電極体１２が並ぶ方向（抵抗器１の長手方向）をＸ方向（第１電極体１１側を＋Ｘ方向、第２電極体１２側を－Ｘ方向）とし、抵抗器１の幅方向をＹ方向（図１の紙面手前側を＋Ｙ方向、図１の紙面奥側を－Ｙ方向）とする。そして、抵抗器１の厚み方向をＺ方向（回路基板に向かう方向を－Ｚ方向、回路基板から離れる方向を＋Ｚ方向）とし、Ｘ方向、Ｙ方向、Ｚ方向は互いに直交するものとする。また、抵抗器１の実装面とは、回路基板に抵抗器１を実装する際に抵抗器１が回路基板に対向する面を意味し、第１電極体１１、抵抗体１０、第２電極体１２の回路基板に対向する面を含む。また実装面の反対面を上面と称す。 In the present embodiment, the direction in which the first electrode body 11 and the second electrode body 12 are arranged (longitudinal direction of the resistor 1) is the X direction (the first electrode body 11 side is the + X direction, and the second electrode body 12 side is the second electrode body 12 side). -X direction), and the width direction of the resistor 1 is the Y direction (the front side of the paper surface in FIG. 1 is the + Y direction, and the back side of the paper surface in FIG. 1 is the -Y direction). Then, the thickness direction of the resistor 1 is set to the Z direction (the direction toward the circuit board is the −Z direction, and the direction away from the circuit board is the + Z direction), and the X direction, the Y direction, and the Z direction are orthogonal to each other. The mounting surface of the resistor 1 means a surface on which the resistor 1 faces the circuit board when the resistor 1 is mounted on the circuit board, and the first electrode body 11, the resistor 10, and the second electrode body. Includes a surface facing the 12 circuit boards. The surface opposite to the mounting surface is referred to as the upper surface.
　本実施形態においては、抵抗体１０は、直方体（又は立方体）形状に形成されている。 In the present embodiment, the resistor 10 is formed in a rectangular parallelepiped (or cubic) shape.
　抵抗体１０は、用途に合わせて低抵抗から高抵抗の材料を用いることが可能である。本実施形態において、抵抗体１０は、大電流を精度よく検出する観点から、比抵抗が小さく、且つ抵抗温度係数（ＴＣＲ）が小さい抵抗体材料であることが好ましい。一例として、銅・マンガン・ニッケル系合金、銅・マンガン・スズ系合金、ニッケル・クロム系合金、銅・ニッケル系合金等を使用することができる。 As the resistor 10, it is possible to use a material having a low resistance to a high resistance according to the application. In the present embodiment, the resistor 10 is preferably a resistor material having a small resistivity and a small temperature coefficient of resistance (TCR) from the viewpoint of accurately detecting a large current. As an example, copper / manganese / nickel alloys, copper / manganese / tin alloys, nickel / chromium alloys, copper / nickel alloys and the like can be used.
　第１電極体１１は、抵抗体１０に接合する胴体部２１と、胴体部２１と一体に形成され回路基板側に延びる脚部２２とを備える。また、第２電極体１２は、抵抗体１０に接合する胴体部３１と、胴体部３１と一体に形成され回路基板側に延びる脚部３２と、を備える。 The first electrode body 11 includes a body portion 21 joined to the resistor body 10 and a leg portion 22 formed integrally with the body portion 21 and extending toward the circuit board. Further, the second electrode body 12 includes a body portion 31 joined to the resistor body 10 and a leg portion 32 formed integrally with the body portion 31 and extending toward the circuit board.
　第１電極体１１（胴体部２１、脚部２２）及び第２電極体１２（胴体部３１、脚部３２）は、安定した検出精度を確保する観点から、電気伝導性及び熱伝導性の良好な導電性材料であることが好ましい。一例として、第１電極体１１及び第２電極体１２として、銅、銅系合金等を使用することができる。銅の中では、無酸素銅（Ｃ１０２０）を使用することが好ましい。第１電極体１１と第２電極体１２とは、互いに同一のものを使用できる。 The first electrode body 11 (body portion 21, leg portion 22) and the second electrode body 12 (body portion 31, leg portion 32) have good electrical conductivity and thermal conductivity from the viewpoint of ensuring stable detection accuracy. It is preferably a conductive material. As an example, copper, a copper-based alloy, or the like can be used as the first electrode body 11 and the second electrode body 12. Among the coppers, it is preferable to use oxygen-free copper (C1020). As the first electrode body 11 and the second electrode body 12, the same ones can be used.
　第１電極体１１における胴体部２１は、抵抗体１０の＋Ｘ方向の端面と略同形状の端面を有し、この端面において抵抗体１０の＋Ｘ方向の端面と突き合わされた態様で接合している。胴体部２１と抵抗体１０との境界部位である接合部１３では、抵抗体１０と胴体部２１との境界に段差がなく平坦であり、抵抗体１０と胴体部２１とは滑らかに連続している。すなわち、接合部１３の表面は、抵抗体１０と胴体部２１との境界全周に亘って平坦（段差がない状態）に形成されている。 The body portion 21 of the first electrode body 11 has an end face having substantially the same shape as the end face of the resistor 10 in the + X direction, and is joined to the end face of the resistor 10 so as to be abutted against the end face of the resistor 10 in the + X direction. .. At the joint portion 13 which is the boundary portion between the body portion 21 and the resistor portion 10, the boundary between the resistor portion 10 and the body portion 21 is flat without a step, and the resistor 10 and the body portion 21 are smoothly continuous. There is. That is, the surface of the joint portion 13 is formed flat (without a step) over the entire boundary between the resistor 10 and the body portion 21.
　第２電極体１２における胴体部３１は、抵抗体１０の－Ｘ方向の端面と略同形状の端面を有し、この端面において抵抗体１０の－Ｘ方向の端面と突き合わされた態様で接合している。胴体部３１と抵抗体１０との境界部位である接合部１４では、抵抗体１０と胴体部３１との境界に段差がなく平坦であり、抵抗体１０と胴体部３１とは滑らかに連続している。すなわち、接合部１４の表面は、抵抗体１０と胴体部３１との境界全周に亘って平坦（段差がない状態）に形成されている。 The body portion 31 of the second electrode body 12 has an end face having substantially the same shape as the end face of the resistor 10 in the −X direction, and is joined in such a manner that the end face is abutted with the end face of the resistor 10 in the −X direction. ing. At the joint portion 14, which is the boundary portion between the body portion 31 and the resistor portion 10, the boundary between the resistor portion 10 and the body portion 31 is flat without a step, and the resistor 10 and the body portion 31 are smoothly continuous. There is. That is, the surface of the joint portion 14 is formed flat (without a step) over the entire boundary between the resistor 10 and the body portion 31.
　脚部２２は、抵抗器１の実装面、即ち胴体部２１の回路基板側から－Ｚ方向に向けて延出した部材である。脚部２２は、胴体部２１よりもＸ方向の長さが短くなっているが、＋Ｘ方向の側面は胴体部２１の＋Ｘ方向の側面と同一平面を形成している。 The leg portion 22 is a member extending from the mounting surface of the resistor 1, that is, the circuit board side of the body portion 21 in the −Z direction. The leg portion 22 has a shorter length in the X direction than the body portion 21, but the side surface in the + X direction forms the same plane as the side surface in the + X direction of the body portion 21.
　脚部３２は、抵抗器１の実装面、即ち胴体部３１の回路基板側から－Ｚ方向に向けて延出した部材である。脚部３２は、胴体部３１よりもＸ方向の長さが短くなっているが、－Ｘ方向の側面は胴体部３１の－Ｘ方向の側面と同一平面を形成している。 The leg portion 32 is a member extending from the mounting surface of the resistor 1, that is, the circuit board side of the body portion 31 toward the −Z direction. The leg portion 32 has a shorter length in the X direction than the body portion 31, but the side surface in the −X direction forms the same plane as the side surface in the −X direction of the body portion 31.
　本実施形態において、抵抗体１０と第１電極体１１との接合部１３、及び抵抗体１０と第２電極体１２との接合部１４の各々は、互いにクラッド接合（固相接合）にて接合している。すなわち、接合面の各々は、抵抗体１０と第１電極体１１の金属原子が互いに拡散した拡散接合面、抵抗体１０と第２電極体１２の金属原子が互いに拡散した拡散接合面、となっている。 In the present embodiment, the joint portion 13 between the resistor 10 and the first electrode body 11 and the joint portion 14 between the resistor 10 and the second electrode body 12 are joined to each other by clad bonding (solid phase bonding). is doing. That is, each of the bonding surfaces is a diffusion bonding surface in which the metal atoms of the resistor 10 and the first electrode body 11 are diffused with each other, and a diffusion bonding surface in which the metal atoms of the resistor 10 and the second electrode body 12 are diffused with each other. ing.
　抵抗器１は、脚部２２及び脚部３２が回路基板側に突出するように回路基板上に実装されることにより、抵抗体１０が回路基板から離間した状態で回路基板に実装される。 The resistor 1 is mounted on the circuit board so that the legs 22 and 32 project toward the circuit board, so that the resistor 10 is mounted on the circuit board in a state of being separated from the circuit board.
　胴体部２１から－Ｘ方向側に突出した部分は突出部２１１であり、突出部２１１が抵抗体１０に接合している。同様に、胴体部３１から＋Ｘ方向側に突出した部分は突出部３１１であり、突出部３１１が抵抗体１０に接合している。 The portion protruding from the body portion 21 in the −X direction is the protruding portion 211, and the protruding portion 211 is joined to the resistor 10. Similarly, the portion protruding from the body portion 31 toward the + X direction is the protruding portion 311, and the protruding portion 311 is joined to the resistor 10.
　抵抗器１の長手方向（Ｘ方向）の長さＬ（図１参照）を一定としたとき、突出部２１１のＸ方向の長さＬ１（胴体部２１の長さ、図１参照）、又は突出部３１１のＸ方向の長さＬ２（胴体部３１のＸ方向の長さ、図１参照）を任意に調整し、抵抗体１０のＸ方向の長さＬ０（図１参照）をＬ０＝Ｌ－（Ｌ１＋Ｌ２）として調整することができる。したがって、抵抗器１の寸法Ｌを変更することなく、また脚部２２，３２の形状を変更することなく、抵抗器１の抵抗値を任意に調整することができる。 When the length L (see FIG. 1) in the longitudinal direction (X direction) of the resistor 1 is constant, the length L1 (length of the body portion 21, see FIG. 1) of the protruding portion 211 in the X direction, or the protrusion. The length L2 of the portion 311 in the X direction (the length of the body portion 31 in the X direction, see FIG. 1) is arbitrarily adjusted, and the length L0 of the resistor 10 in the X direction (see FIG. 1) is set to L0 = L−. It can be adjusted as (L1 + L2). Therefore, the resistance value of the resistor 1 can be arbitrarily adjusted without changing the dimension L of the resistor 1 and without changing the shapes of the legs 22 and 32.
　ここで、抵抗体１０の長手方向（Ｘ方向）における抵抗体１０の長さＬ０と、第１電極体１１のＸ方向の長さＬ１と、第２電極体１２のＸ方向の長さＬ２の比は、任意に設定することができる。ただし、ＴＣＲ（抵抗温度係数［ｐｐｍ／℃］）の増加を抑制しつつ、抵抗値を小さくする観点から、Ｌ１：Ｌ０：Ｌ２＝１：２：１、若しくは１：２：１近傍であることが好ましい。 Here, the length L0 of the resistor 10 in the longitudinal direction (X direction) of the resistor 10, the length L1 of the first electrode body 11 in the X direction, and the length L2 of the second electrode body 12 in the X direction. The ratio can be set arbitrarily. However, from the viewpoint of reducing the resistance value while suppressing the increase in TCR (temperature coefficient of resistance [ppm / ° C.]), it should be in the vicinity of L1: L0: L2 = 1: 2: 1 or 1: 2: 1. Is preferable.
　更に、放熱性を高めるとともに、抵抗値を小さくする観点から、抵抗器１の長さＬ（＝Ｌ１＋Ｌ０＋Ｌ２）に対する抵抗体１０の長さＬ０の比率は、５０％以下であることが好ましい。 Further, from the viewpoint of improving heat dissipation and reducing the resistance value, the ratio of the length L0 of the resistor 10 to the length L (= L1 + L0 + L2) of the resistor 1 is preferably 50% or less.
　本実施形態において、抵抗器１は、表面に、筋状凹凸１５（図１の拡大図、図２の拡大図参照）を有する。本実施形態においては、筋状凹凸１５は、抵抗器１の＋Ｙ方向に対向する側面、及び－Ｙ方向に対向する側面以外の側面においてＹ方向に沿って延びるように形成されている。 In the present embodiment, the resistor 1 has a streak-like unevenness 15 (see the enlarged view of FIG. 1 and the enlarged view of FIG. 2) on the surface. In the present embodiment, the streak-like unevenness 15 is formed so as to extend along the Y direction on the side surface of the resistor 1 facing the + Y direction and the side surface other than the side surface facing the −Y direction.
　筋状凹凸１５の凹部と凸部による表面粗さは、算術平均粗さ（Ｒａ）で０．２～０．３μｍとすることができる。 The surface roughness due to the concave and convex portions of the streak-like unevenness 15 can be 0.2 to 0.3 μm in arithmetic average roughness (Ra).
　本実施形態において、Ｘ方向における抵抗器１の長さＬは、３．２ｍｍ以下になるように形成されている。また、抵抗器１の抵抗値が２ｍΩ以下になるように調整されている。 In the present embodiment, the length L of the resistor 1 in the X direction is formed to be 3.2 mm or less. Further, the resistance value of the resistor 1 is adjusted to be 2 mΩ or less.
　本実施形態においては、高密度回路基板に適合させる観点から、Ｘ方向における抵抗器１の長さＬが、３．２ｍｍ以下、Ｙ方向における抵抗器１の長さ（幅）Ｗが１．６ｍｍ以下（製品規格３２１６サイズ）とすることができる。よって、本実施形態の抵抗器１のサイズとしては、製品規格２０１２サイズ（Ｌ：２，０ｍｍ、Ｗ：１．２ｍｍ）、製品規格１６０８サイズ（Ｌ：１．６ｍｍ，Ｗ：０．８ｍｍ）、製品規格１００５サイズ（Ｌ：１．０ｍｍ、Ｗ：０．５ｍｍ）にも適用可能である。本実施形態の抵抗器１の長さＬは、後述する製造方法における取り扱い性、例えば抵抗器１の基となる抵抗器母材１００（図１４参照）の破断防止の観点から、上記の製品規格１００５サイズ以上のサイズとすることができる。 In the present embodiment, from the viewpoint of adapting to a high-density circuit board, the length L of the resistor 1 in the X direction is 3.2 mm or less, and the length (width) W of the resistor 1 in the Y direction is 1.6 mm. The following (product standard 3216 size) can be used. Therefore, as the size of the resistor 1 of the present embodiment, the product standard 2012 size (L: 2.0 mm, W: 1.2 mm), the product standard 1608 size (L: 1.6 mm, W: 0.8 mm), It is also applicable to product standard 1005 size (L: 1.0 mm, W: 0.5 mm). The length L of the resistor 1 of the present embodiment is the above-mentioned product standard from the viewpoint of handleability in the manufacturing method described later, for example, prevention of breakage of the resistor base material 100 (see FIG. 14) which is the base of the resistor 1. The size can be 1005 or more.
　本実施形態においては、抵抗器１の抵抗値は、小型且つ低抵抗を実現する観点から上記のいずれのサイズにおいても２ｍΩ以下となるように調整可能であり、例えば０．５ｍΩ以下となるように調整可能である。ここでの低抵抗とは、一般的な抵抗器（例えば、特開２００２－５７００９号公報のタイプの抵抗器）の寸法から想定される抵抗値よりも低い抵抗値を含む概念である。 In the present embodiment, the resistance value of the resistor 1 can be adjusted to be 2 mΩ or less in any of the above sizes from the viewpoint of realizing small size and low resistance, for example, 0.5 mΩ or less. It is adjustable. The low resistance here is a concept including a resistance value lower than the resistance value assumed from the dimensions of a general resistor (for example, a resistor of the type of JP-A-2002-57009).
　本実施形態において、抵抗器１のＹ方向に延びる縁辺である角部分Ｐは、いずれも面取り形状を有している。本実施形態では、角部分Ｐの曲率半径は、Ｒ＝０．１ｍｍ以下であることが好ましい。 In the present embodiment, the corner portions P, which are the edges extending in the Y direction of the resistor 1, all have a chamfered shape. In the present embodiment, the radius of curvature of the corner portion P is preferably R = 0.1 mm or less.
　図１、図２に示すように、本実施形態の抵抗器１の実装面側（実装面のみならず、抵抗器１のＹ方向に対向する側面であって実装面に近傍の領域を含む）には凹部６が形成されている。凹部６は、抵抗器１の抵抗値を調整するために形成されたものである。凹部６は、抵抗器１の実装面側の接合部１３、及び接合部１４に沿って形成されている。これについては図３乃至図５を参照して後述する。 As shown in FIGS. 1 and 2, the mounting surface side of the resistor 1 of the present embodiment (not only the mounting surface but also the side surface of the resistor 1 facing the Y direction and including a region near the mounting surface). A recess 6 is formed in the hole. The recess 6 is formed to adjust the resistance value of the resistor 1. The recess 6 is formed along the joint portion 13 and the joint portion 14 on the mounting surface side of the resistor 1. This will be described later with reference to FIGS. 3 to 5.
＜凹部６＞
　図３は、抵抗器１の実装面を示す図であって凹部６を説明するための図である。図４は、図３に示す抵抗器１の側面図、及び抵抗器１の熱分布を示す図である。図５は、凹部６の変形例の側面図である。 <Recess 6>
FIG. 3 is a diagram showing a mounting surface of the resistor 1 and is a diagram for explaining the recess 6. FIG. 4 is a side view of the resistor 1 shown in FIG. 3 and a diagram showing the heat distribution of the resistor 1. FIG. 5 is a side view of a modified example of the recess 6.
　図３、図４に示すように、凹部６（６ａ）は、抵抗器１の実装面側の接合部１３を跨ぐように配置され、Ｙ方向に延びるように抵抗体１０及び第１電極体１１に形成されている。凹部６（６ｂ）は、抵抗器１の実装面側の接合部１４を跨ぐように配置され、Ｙ方向に延びるように抵抗体１０及び第２電極体１２に形成されている。凹部６（６ａ，６ｂ）の＋Ｙ方向の端部は、抵抗器１の＋Ｙ方向に対向する側面に開口しており、凹部６（６ａ，６ｂ）の－Ｙ方向の端部は、抵抗器１の－Ｙ方向に対向する側面に対して開口している。凹部６（６ａ，６ｂ）は溝状の窪みであって、Ｙ方向から見た断面は、略半円形（若しくは矩形、不定形）となっている。 As shown in FIGS. 3 and 4, the recess 6 (6a) is arranged so as to straddle the joint portion 13 on the mounting surface side of the resistor 1, and the resistor 10 and the first electrode body 11 extend in the Y direction. Is formed in. The recess 6 (6b) is arranged so as to straddle the joint portion 14 on the mounting surface side of the resistor 1, and is formed in the resistor 10 and the second electrode body 12 so as to extend in the Y direction. The + Y-direction end of the recess 6 (6a, 6b) is open to the side surface of the resistor 1 facing the + Y direction, and the −Y-direction end of the recess 6 (6a, 6b) is the resistor 1. It is open to the side surface facing the −Y direction of. The recesses 6 (6a, 6b) are groove-shaped recesses, and the cross section seen from the Y direction is substantially semicircular (or rectangular, amorphous).
　図５に示すように、変形例となる凹部６（６ｃ，６ｄ）は、図４、図５に示す凹部６（６ａ，６ｂ）と同様に抵抗器１をＹ方向に延びるように形成されているが、いずれも抵抗体１０のみの領域にＹ方向に溝切りするように形成されている。凹部６（６ｃ）の＋Ｘ方向（凹部６（６ｃ）の幅方向）の端部が接合部１３と重なっている。凹部６（６ｄ）の－Ｘ方向（凹部６（６ｄ）の幅方向）の端部が接合部１４と重なっている。凹部６（６ｃ，６ｄ）のＹ方向から見た断面も、略半円形（若しくは矩形、不定形）となっている。 As shown in FIG. 5, the recess 6 (6c, 6d) as a modification is formed so as to extend the resistor 1 in the Y direction like the recess 6 (6a, 6b) shown in FIGS. 4 and 5. However, all of them are formed so as to be grooved in the Y direction in the region of only the resistor 10. The end portion of the recess 6 (6c) in the + X direction (the width direction of the recess 6 (6c)) overlaps with the joint portion 13. The end portion of the recess 6 (6d) in the −X direction (the width direction of the recess 6 (6d)) overlaps with the joint portion 14. The cross section of the recess 6 (6c, 6d) seen from the Y direction is also substantially semicircular (or rectangular, amorphous).
　抵抗器１の電流供給時の熱分布は、図４に示すようになる。すなわち、抵抗体１０のＸ方向の中央部で最も温度が高い極大値となり、中央部からＸ方向に離れるごとに温度低下しつつ温度勾配が低温側に傾く。そして、その後温度勾配が最大となる変曲点（変曲点ａ、変曲点ｂ）に到達し、以後電極に近づくにつれて温度低下しつつも温度勾配が小さくなる熱分布となる。 The heat distribution of the resistor 1 when the current is supplied is as shown in FIG. That is, the maximum temperature is the highest in the central portion of the resistor 10 in the X direction, and the temperature gradient is inclined to the low temperature side while the temperature is lowered each time the resistor 10 is separated from the central portion in the X direction. After that, the heat distribution reaches the inflection point (inflection point a, inflection point b) where the temperature gradient becomes maximum, and then the temperature decreases as the temperature approaches the electrode, but the temperature gradient becomes smaller.
　抵抗体１０の一部を切除（トリミング）することにより、抵抗値を高抵抗側にシフトさせる態様で抵抗値の調整が一般的に行われている。しかし、例えば抵抗体１０のＸ方向の中央部及びその近傍、又は上記の変曲点及びその近傍となる位置で抵抗体１０の一部を切除すると、抵抗体１０全体の熱分布が設計上の熱分布から大きく変化する虞がある。また、抵抗器１に電力を印加すると抵抗体１０において発熱するが、抵抗体１０の長手方向（Ｘ方向）の中央部分が最も高い温度となり、当該中央部分の特性が抵抗器１全体の熱分布に最も大きな影響を与える。よって、当該中央部分にトリミングによる幅狭部を形成すると抵抗器１の熱分布が大きく変化する。したがって、このような抵抗体１０を含む抵抗器を回路基板に実装して使用すると、当該抵抗器１のみならず回路基板の熱分布も設計上の熱分布から変化し、抵抗器及び回路基板に悪影響を及ぼす虞がある。 The resistance value is generally adjusted in such a manner that the resistance value is shifted to the high resistance side by cutting (trimming) a part of the resistor 10. However, for example, when a part of the resistor 10 is cut off at the center of the resistor 10 in the X direction and its vicinity, or at the above-mentioned inflection point and its vicinity, the heat distribution of the entire resistor 10 is designed. There is a risk of significant changes from the heat distribution. Further, when electric power is applied to the resistor 1, the resistor 10 generates heat, but the central portion of the resistor 10 in the longitudinal direction (X direction) has the highest temperature, and the characteristic of the central portion is the heat distribution of the entire resistor 1. Has the greatest impact on. Therefore, if a narrow portion is formed by trimming in the central portion, the heat distribution of the resistor 1 changes significantly. Therefore, when a resistor including such a resistor 10 is mounted on a circuit board and used, not only the resistor 1 but also the heat distribution of the circuit board changes from the design heat distribution, and the resistor and the circuit board have the same heat distribution. There is a risk of adverse effects.
　そこで、本実施形態では、図３乃至図５に示すように、トリミング痕である凹部６（６ａ，６ｃ）が抵抗体１０において接合部１３近傍、すなわち上記の変曲点ａよりも第１電極体１１側に形成されている。同様に、トリミング痕である凹部６（６ｂ，６ｄ）が抵抗体１０において接合部１４近傍、すなわち上記の変曲点ｂよりも第２電極体１２側に形成されている。これにより、熱分布の変化を抑制しつつ抵抗値の調整を行うことができる。 Therefore, in the present embodiment, as shown in FIGS. 3 to 5, the recesses 6 (6a, 6c), which are trimming marks, are located near the joint portion 13 in the resistor 10, that is, the first electrode is located at the inflection point a. It is formed on the body 11 side. Similarly, the recesses 6 (6b, 6d), which are trimming marks, are formed in the resistor 10 in the vicinity of the joint portion 14, that is, on the second electrode body 12 side of the above-mentioned inflection point b. This makes it possible to adjust the resistance value while suppressing changes in the heat distribution.
　ところで、本実施形態では、トリミングはレーザを少なくとも抵抗体１０（及び第１電極体１１、第２電極体１２）に照射することにより行い、そのトリミング痕として凹部６が形成される。この方法で凹部６を形成すると、凹部６の内壁、又は凹部６の内壁及びその周縁には酸化膜が形成される。酸化膜は、抵抗体１０、第１電極体１１、第２電極体１２、のいずれかの表面にレーザ照射して加熱することで形成される熱酸化膜である。この酸化膜は半田に対する濡れ性が低いことが知られている。 By the way, in the present embodiment, trimming is performed by irradiating at least the resistor 10 (and the first electrode body 11 and the second electrode body 12) with a laser, and a recess 6 is formed as a trimming mark thereof. When the recess 6 is formed by this method, an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the periphery thereof. The oxide film is a thermal oxide film formed by irradiating the surface of any one of the resistor 10, the first electrode body 11, and the second electrode body 12 with a laser and heating the surface. It is known that this oxide film has low wettability with respect to solder.
　また、本実施形態の抵抗器１はリフロー工程により回路基板に実装されるが、その際、半田が脚部２２，３２を這い上がりやすい。 Further, the resistor 1 of the present embodiment is mounted on the circuit board by the reflow process, and at that time, the solder easily crawls up the legs 22 and 32.
　しかし、図３乃至図５に示すように、凹部６は、Ｙ方向に延び、且つ抵抗器１の＋Ｙ方向に対向する側面及び－Ｙ方向に対向する側面を開口するように抵抗体１０（及び第１電極体１１、第２電極体１２）において形成されている。これにより、リフロー工程で脚部２２，３２を這い上がってきた半田が抵抗体１０に這い上がる経路を当該酸化膜により遮断することができる。よってリフロー工程において半田が抵抗体１０に接触することを回避して、抵抗器１を用いた電流の検出精度の低下を回避することができる。 However, as shown in FIGS. 3 to 5, the recess 6 extends in the Y direction and opens the side surface of the resistor 1 facing the + Y direction and the side surface facing the −Y direction of the resistor 10 (and). It is formed in the first electrode body 11 and the second electrode body 12). As a result, the oxide film can block the path through which the solder that has crawled up the legs 22 and 32 in the reflow process climbs up to the resistor 10. Therefore, it is possible to prevent the solder from coming into contact with the resistor 10 in the reflow process, and to avoid a decrease in current detection accuracy using the resistor 1.
　例えば、図３、図４に示す凹部６（６ａ、６ｂ）の配置においては、脚部２２を這い上がった半田は、胴体部２１上の位置であって凹部６ａの＋Ｘ方向の端部よりも抵抗体１０側（－Ｘ方向側）への這い上がりが阻止される。そして、脚部３２を這い上がった半田は、胴体部３１上の位置であって凹部６ｂの－Ｘ方向の端部よりも抵抗体１０側（＋Ｘ方向側）への這い上がりが阻止される。 For example, in the arrangement of the recesses 6 (6a, 6b) shown in FIGS. Crawling up to the resistor 10 side (-X direction side) is prevented. Then, the solder that crawls up the leg portion 32 is at a position on the body portion 31 and is prevented from crawling up toward the resistor 10 side (+ X direction side) from the end portion of the recess 6b in the −X direction.
　図５に示す凹部６（６ｃ，６ｄ）の配置において、脚部２２を這い上がった半田は、実装面の第１電極体１１の抵抗体１０との接合位置（接合部１３）から抵抗体１０側（－Ｘ方向側）への這い上がりが阻止される。そして、脚部３２を這い上がった半田は、実装面の第２電極体１２の抵抗体１０との接合位置（接合部１４）から抵抗体１０側（－Ｘ方向側）への這い上がりが阻止される。逆に言えば、半田は、実装面の第１電極体１１の抵抗体１０との接合位置（接合部１３）、及び実装面の第２電極体１２の抵抗体１０との接合位置（接合部１４）まで及ぶ。このため、第１電極体１１及び第２電極体１２のＴＣＲの温度変化を、図３、図４の凹部６（６ａ，６ｂ）の配置に比べて、より効果的に相殺することができる。 In the arrangement of the recesses 6 (6c, 6d) shown in FIG. 5, the solder that crawls up the leg 22 is the resistor 10 from the joint position (joint 13) of the first electrode body 11 on the mounting surface with the resistor 10. Crawling to the side (-X direction side) is prevented. Then, the solder that crawls up the leg portion 32 prevents the solder that crawls up from the joint position (joint portion 14) of the second electrode body 12 of the mounting surface to the resistor 10 to the resistor 10 side (−X direction side). Will be done. Conversely, in the solder, the bonding position of the first electrode body 11 on the mounting surface with the resistor 10 (joining portion 13) and the bonding position of the second electrode body 12 on the mounting surface with the resistor 10 (joining portion). It extends to 14). Therefore, the temperature change of the TCR of the first electrode body 11 and the second electrode body 12 can be more effectively offset as compared with the arrangement of the recesses 6 (6a, 6b) of FIGS. 3 and 4.
＜トリミングによる凹部６の形成＞
　図６は、本実施形態の抵抗器１に凹部６を形成する場合の模式図である。 <Formation of recess 6 by trimming>
FIG. 6 is a schematic view in the case where the recess 6 is formed in the resistor 1 of the present embodiment.
　本実施形態の抵抗器１において、上記のようにレーザ照射により抵抗体１０をトリミングすることでトリミング痕として凹部６が形成され、当該凹部６の内壁、又は凹部６の内壁及びその周縁に酸化膜が形成される。よって、レーザ照射によるトリミングでは、抵抗値の調整と、半田の這い上がりを阻止する加工とを同時に行うことができる。 In the resistor 1 of the present embodiment, by trimming the resistor 10 by laser irradiation as described above, a recess 6 is formed as a trimming mark, and an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the periphery thereof. Is formed. Therefore, in the trimming by laser irradiation, the resistance value can be adjusted and the solder can be prevented from creeping up at the same time.
　図６に示すように、トリミングにおいては、抵抗器１の実装面側のうち、接合部１３を含む所定の範囲、及び接合部１４を含む所定の範囲に対してレーザを照射する。上記のように抵抗値の調整と半田の這い上がりを阻止する加工を効率的に行う場合、レーザを接合部１３（境界部位）及び接合部１４（境界部位）のみに照射することが好適である。 As shown in FIG. 6, in trimming, the laser is irradiated to a predetermined range including the joint portion 13 and a predetermined range including the joint portion 14 on the mounting surface side of the resistor 1. In order to efficiently adjust the resistance value and prevent the solder from creeping up as described above, it is preferable to irradiate only the joint portion 13 (boundary portion) and the joint portion 14 (boundary portion) with the laser. ..
　ところで、本実施形態の抵抗器１は、後述のように（図１０、図１１参照）、抵抗体母材１０Ａを電極体母材１１Ａ，１２Ａで挟み込んだ状態でクラッド接合（固相接合）した抵抗器母材１００をダイス３００に挿通して断面積を縮小させつつ断面形状を抵抗器１の断面形状に変形させ、ダイス３００に挿通後の抵抗器母材１００を切断することで形成される。よって、接合部１３（境界部位）及び接合部１４（境界部位）は、通常平面（直線）となるが、わずかに蛇行する場合がある。この場合、接合部１３及び接合部１４のみを狙ってレーザ照射を行うことは困難である。 By the way, as described later (see FIGS. 10 and 11), the resistor 1 of the present embodiment is clad-bonded (solid-phase bonded) with the resistor base material 10A sandwiched between the electrode body base materials 11A and 12A. It is formed by inserting the resistor base material 100 into the die 300 to reduce the cross-sectional area, transforming the cross-sectional shape into the cross-sectional shape of the resistor 1, and cutting the resistor base material 100 after being inserted into the die 300. .. Therefore, the joint portion 13 (boundary portion) and the joint portion 14 (boundary portion) are usually flat surfaces (straight lines), but may meander slightly. In this case, it is difficult to irradiate the laser only at the joint portion 13 and the joint portion 14.
　そこで、図６の拡大図に示すように、接合部１３において抵抗体１０及び第１電極体１１にレーザが照射される。その際、接合部１４において抵抗体１０及び第２電極体１２にレーザが照射されるようにレーザの照射エリア５１（Ｘ方向の幅：０．１ｍｍ～０．１５ｍｍ）がそれぞれ設定することが好ましい。 Therefore, as shown in the enlarged view of FIG. 6, the resistor 10 and the first electrode body 11 are irradiated with the laser at the joint portion 13. At that time, it is preferable to set the laser irradiation area 51 (width in the X direction: 0.1 mm to 0.15 mm) so that the resistor 10 and the second electrode body 12 are irradiated with the laser at the joint portion 14. ..
　図６の拡大図中の矢印（レーザの照射位置の軌跡）で示すように、レーザは、例えば照射エリア５１の－Ｘ方向の端部であって平面視で抵抗器１から離間した位置から＋Ｙ方向に移動して抵抗器１上を照射して平面視で抵抗器１から離間した位置まで移動する。その後レーザは、＋Ｘ方向にわずかに移動（移動量はレーザの抵抗器１上のスポット径よりも小さい）して－Ｙ方向に移動して抵抗器１上を照射して平面視で抵抗器１から離間した位置まで移動する。以後同様の動作を繰り返して照射エリア５１全体にレーザを照射する。 As shown by the arrow (trajectory of the laser irradiation position) in the enlarged view of FIG. 6, the laser is, for example, + Y from a position at the end of the irradiation area 51 in the −X direction and separated from the resistor 1 in a plan view. It moves in the direction, irradiates the resistor 1, and moves to a position away from the resistor 1 in a plan view. After that, the laser moves slightly in the + X direction (the amount of movement is smaller than the spot diameter on the resistor 1 of the laser), moves in the −Y direction, irradiates the resistor 1 and irradiates the resistor 1 in a plan view. Move to a position away from. After that, the same operation is repeated to irradiate the entire irradiation area 51 with the laser.
　レーザは、その出力が発振直後に過大又は過小となるなど安定しない虞がある。そこで、上記のように、平面視で抵抗器１から離間した位置（抵抗器１にレーザが照射されない位置）からレーザの発振を開始して出力が安定したレーザを抵抗器１に照射することが望ましい。 The laser may not be stable because its output becomes excessive or too small immediately after oscillation. Therefore, as described above, it is possible to start oscillating the laser from a position separated from the resistor 1 in a plan view (a position where the laser is not irradiated to the resistor 1) and irradiate the resistor 1 with a laser having a stable output. desirable.
　また抵抗器１にレーザを照射しているときは、抵抗値が安定しないので、レーザ照射後に抵抗値を測定し、当該抵抗値が所望の抵抗値になるまでレーザ照射と抵抗値の測定を交互に繰り返せばよい。 Further, when the resistor 1 is irradiated with the laser, the resistance value is not stable. Therefore, the resistance value is measured after the laser irradiation, and the laser irradiation and the measurement of the resistance value are alternately performed until the resistance value reaches the desired resistance value. You can repeat it.
　図７は、本実施形態の抵抗器１を半田実装したときの断面写真である。図７に示す抵抗器１は、上記と同様に抵抗体１０の端面と第１電極体１１の端面を突き合わせ、抵抗体１０の端面と第２電極体１２の端面とを突き合わせてクラッド接合により形成したものである。ここで、抵抗器１の実装面側において、第２電極体１２と抵抗体１０との接合部１４を跨ぐ境界部位には酸化膜を形成しているが、第１電極体１１と抵抗体１０との接合部１３を跨ぐ境界部位には酸化膜は形成していない。 FIG. 7 is a cross-sectional photograph of the resistor 1 of the present embodiment solder-mounted. The resistor 1 shown in FIG. 7 is formed by clad bonding by abutting the end face of the resistor 10 and the end face of the first electrode body 11 and abutting the end face of the resistor 10 and the end face of the second electrode body 12 in the same manner as described above. It was done. Here, on the mounting surface side of the resistor 1, an oxide film is formed at the boundary portion straddling the joint portion 14 between the second electrode body 12 and the resistor 10, but the first electrode body 11 and the resistor 10 are formed. No oxide film is formed at the boundary portion straddling the joint portion 13.
　そして、リフロー工程により抵抗器１を半田９を介して回路基板７に実装した。その結果、右側の第１電極体１１の脚部２２に接触した半田９は、当該脚部２２を這い上がり、実装面において突出部２１１を経て抵抗体１０にまで這い上がり、抵抗体１０に接触した状態となっている。一方、第２電極体１２の脚部３２に接触した半田９は当該脚部３２を這い上がり実装面において突出部３１１にまで這い上がるものの、酸化膜に接触する位置で這い上がりが阻止されている。したがって、実際の抵抗器１において、第２電極体１２と抵抗体１０との接合部１４を跨ぐ境界部位、及び第１電極体１１と抵抗体１０との接合部１３を跨ぐ境界部位に、酸化膜を備える凹部６をそれぞれ形成する。これにより、半田９の抵抗体１０への這い上がりを阻止可能であることが容易に理解できる。 Then, the resistor 1 was mounted on the circuit board 7 via the solder 9 by the reflow process. As a result, the solder 9 that has come into contact with the leg portion 22 of the first electrode body 11 on the right side crawls up the leg portion 22, crawls up to the resistor 10 via the protrusion 211 on the mounting surface, and contacts the resistor 10. It is in a state of being. On the other hand, the solder 9 in contact with the leg portion 32 of the second electrode body 12 crawls up the leg portion 32 and crawls up to the protruding portion 311 on the mounting surface, but the crawl up is prevented at a position in contact with the oxide film. .. Therefore, in the actual resistor 1, the boundary portion straddling the joint portion 14 between the second electrode body 12 and the resistor 10 and the boundary portion straddling the joint portion 13 between the first electrode body 11 and the resistor 10 are oxidized. Each of the recesses 6 having a film is formed. It can be easily understood that this makes it possible to prevent the solder 9 from climbing up to the resistor 10.
＜変形例＞
　図８は、本実施形態の抵抗器１の変形例を示す側面図である。図９は、本実施形態の抵抗器１の変形例を示す平面図である。本実施形態の抵抗器１の変形例は、第１電極体１１の脚部２２、第２電極体１２の脚部３２がなく、抵抗器１の実装面が平坦となっている。一方、回路基板７には電極７１，７２が配置され、電極７１，７２は、回路基板７から突出するように配置されている。電極７１には第１電極体１１が半田（不図示）により実装されており、電極７２には第２電極体１２が半田（不図示）により実装されている。このとき、抵抗体１０は、回路基板７からわずかに離間して配置されている。 <Modification example>
FIG. 8 is a side view showing a modified example of the resistor 1 of the present embodiment. FIG. 9 is a plan view showing a modified example of the resistor 1 of the present embodiment. In the modified example of the resistor 1 of the present embodiment, the leg portion 22 of the first electrode body 11 and the leg portion 32 of the second electrode body 12 are not provided, and the mounting surface of the resistor 1 is flat. On the other hand, the electrodes 71 and 72 are arranged on the circuit board 7, and the electrodes 71 and 72 are arranged so as to project from the circuit board 7. The first electrode body 11 is mounted on the electrode 71 by solder (not shown), and the second electrode body 12 is mounted on the electrode 72 by solder (not shown). At this time, the resistor 10 is arranged slightly separated from the circuit board 7.
　上記と同様に抵抗器１の実装面側において、例えば接合部１３を跨ぐように凹部６（６ｅ）が形成され、接合部１４を跨ぐように凹部６（６ｆ）が形成されている。凹部６（６ｅ，６ｆ）は，上記のようにレーザ照射によりＹ方向に延び、且つ抵抗器１の＋Ｙ方向に対向する側面及び抵抗器１の－Ｙ方向に対向する側面を開口するように抵抗器１に形成されており、内壁およびその周縁には酸化膜が形成されている。このため、リフロー工程において、第１電極体１１を這い上がってきた半田が接合部１３に形成された凹部６（６ｅ）（酸化膜）を超えて抵抗体１０にまで這い上がることを阻止できる。また第２電極体１２を這い上がってきた半田が接合部１４に形成された凹部６（６ｆ）（酸化膜）を超えて抵抗体１０にまで這い上がることも阻止できる。 Similar to the above, on the mounting surface side of the resistor 1, for example, a recess 6 (6e) is formed so as to straddle the joint portion 13, and a recess 6 (6f) is formed so as to straddle the joint portion 14. The recesses 6 (6e, 6f) extend in the Y direction by laser irradiation as described above, and resist so as to open the side surface of the resistor 1 facing the + Y direction and the side surface of the resistor 1 facing the −Y direction. It is formed in the vessel 1, and an oxide film is formed on the inner wall and its periphery. Therefore, in the reflow step, it is possible to prevent the solder that has crawled up the first electrode body 11 from crawling up to the resistor 10 beyond the recess 6 (6e) (oxide film) formed in the joint portion 13. Further, it is possible to prevent the solder crawling up on the second electrode body 12 from crawling up to the resistor 10 beyond the recess 6 (6f) (oxide film) formed in the joint portion 14.
　一方、抵抗器１の上面において、接合部１３を跨ぐように凹部６（６ｇ）が形成され、接合部１４を跨ぐように凹部６（６ｈ）が形成されている。 On the other hand, on the upper surface of the resistor 1, a recess 6 (6 g) is formed so as to straddle the joint portion 13, and a recess 6 (6 h) is formed so as to straddle the joint portion 14.
　凹部６（６ｇ）は、上面において接合部１３の一部をトリミングする態様でＹ方向の両端（それ以外の場所でもよい）に形成されている。凹部６（６ｈ）は、上面において接合部１４の一部をトリミングする態様でＹ方向の両端（それ以外の場所でもよい）に形成されている。 The recesses 6 (6 g) are formed at both ends in the Y direction (may be other places) in a manner of trimming a part of the joint portion 13 on the upper surface. The recesses 6 (6h) are formed at both ends in the Y direction (may be other places) in a manner of trimming a part of the joint portion 14 on the upper surface.
　凹部６（６ｇ，６ｈ）は、抵抗値を調整するために形成されたものである。よって、凹部６（６ｇ，６ｈ）は抵抗器１の上面においてＹ方向に端から端まで到達する態様で形成する必要はなく、また内壁に酸化膜がなくてもよい。凹部６（６ｇ，６ｈ）は、実装面側に形成した凹部６（６ｅ，６ｆ）のみでは抵抗値の調整が不十分の場合に有効な構成要素となる。なお、凹部６（６ｇ）は、抵抗器１の＋Ｙ方向の側面、及び／又は、－Ｙ方向の側面であって接合部１３と重なる位置に形成してもよい。同様に、凹部６（６ｈ）は、抵抗器１の＋Ｙ方向の側面、及び／又は、－Ｙ方向の側面であって接合部１４と重なる位置に形成してもよい。 The recess 6 (6g, 6h) is formed to adjust the resistance value. Therefore, the recesses 6 (6g, 6h) need not be formed on the upper surface of the resistor 1 in a manner that reaches from end to end in the Y direction, and the inner wall may not have an oxide film. The recess 6 (6g, 6h) is an effective component when the resistance value is not sufficiently adjusted only by the recess 6 (6e, 6f) formed on the mounting surface side. The recess 6 (6 g) may be formed at a position on the side surface of the resistor 1 in the + Y direction and / or the side surface in the −Y direction and overlapping the joint portion 13. Similarly, the recess 6 (6h) may be formed at a position on the side surface of the resistor 1 in the + Y direction and / or the side surface in the −Y direction and overlapping the joint portion 14.
　なお、実装面側に形成した凹部６（６ａ，６ｂ，６ｃ，６ｄ，６ｅ，６ｆ）は、酸化膜がない状態で形成可能であり、例えば後述のダイス３００において開口部３０１（出口開口３０３）に凹部６の外形に倣った形状を追加した状態で抵抗器母材１００を開口部３０１に挿通することでも形成が可能である。 The recesses 6 (6a, 6b, 6c, 6d, 6e, 6f) formed on the mounting surface side can be formed without an oxide film. For example, in the die 300 described later, the opening 301 (outlet opening 303) It can also be formed by inserting the resistor base material 100 into the opening 301 with a shape that follows the outer shape of the recess 6 added to the recess 6.
＜本実施形態の効果＞
　次に、本実施形態による作用効果について説明する。 <Effect of this embodiment>
Next, the action and effect of this embodiment will be described.
　本実施形態の抵抗器１の製造方法によれば、抵抗体１０と、抵抗体１０に接続された一対の電極（第１電極体１１、第２電極体１２）と、を備え、抵抗体１０の一部にトリミングを行うことにより抵抗値の調整が可能な抵抗器１の製造方法であって、抵抗体１０と電極（第１電極体１１、第２電極体１２）の境界部位（接合部１３、接合部１４）における抵抗体１０にトリミングとして凹部６を形成する。 According to the method for manufacturing the resistor 1 of the present embodiment, the resistor 10 includes a resistor 10 and a pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10. This is a method for manufacturing a resistor 1 whose resistance value can be adjusted by trimming a part of the resistor 1, and is a boundary portion (joint portion) between the resistor 10 and an electrode (first electrode body 11, second electrode body 12). A recess 6 is formed in the resistor 10 at the joint portion 14) as a trimming.
　上記方法により、電流投入時に抵抗体１０は発熱するが、抵抗体１０は抵抗体１０と電極（第１電極体１１、第２電極体１２）との境界部位（接合部１３、接合部１４）において最も温度が低い状態となる。よって、当該境界部位（接合部１３、接合部１４）にトリミングとして凹部６を形成することで、抵抗器１の熱分布の変化を低減しつつ抵抗値を調整することができる。 According to the above method, the resistor 10 generates heat when a current is applied, but the resistor 10 has a boundary portion (joint portion 13, joint portion 14) between the resistor 10 and the electrodes (first electrode body 11, second electrode body 12). Is the lowest temperature. Therefore, by forming the recess 6 as a trimming in the boundary portion (joint portion 13, joint portion 14), the resistance value can be adjusted while reducing the change in the heat distribution of the resistor 1.
　本実施形態において、凹部６を、抵抗体１０及び一対の電極（第１電極体１１、第２電極体１２）が共に基板（回路基板）に対向する向きで基板（回路基板）に実装する際の抵抗器１の実装面に形成する。これにより、凹部６を抵抗器１の実装面側の反対面（上面）に凹部６を形成せず、当該反対面は平坦性を維持できるので、抵抗器１を実装時に抵抗器１を負圧により吸引して保持するノズルの吸着性を確保することができる。また凹部６をレーザ照射により形成すると凹部６の内壁、又は凹部６の内壁及びその周縁に酸化膜が形成されるが、当該酸化膜は実装時の半田の這い上がりを阻止することができる。よって、抵抗体１０が半田に接触することを阻止して抵抗器１を用いた電流測定における検出精度の低下を回避することができる。 In the present embodiment, when the recess 6 is mounted on the substrate (circuit board) with the resistor 10 and the pair of electrodes (first electrode body 11, second electrode body 12) both facing the substrate (circuit board). It is formed on the mounting surface of the resistor 1 of. As a result, the recess 6 is not formed on the opposite surface (upper surface) of the resistor 1 on the mounting surface side, and the opposite surface can maintain flatness. Therefore, when the resistor 1 is mounted, the resistor 1 is subjected to negative pressure. This makes it possible to secure the adsorptivity of the nozzle that sucks and holds. Further, when the recess 6 is formed by laser irradiation, an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the peripheral edge thereof, and the oxide film can prevent the solder from creeping up during mounting. Therefore, it is possible to prevent the resistor 10 from coming into contact with the solder and avoid a decrease in detection accuracy in the current measurement using the resistor 1.
　本実施形態において、電極（第１電極体１１、第２電極体１２）は、抵抗体１０に接続する胴体部２１，３１と、胴体部２１，３１から基板（回路基板）の方向に突出した脚部２２，３２とを有する。これにより、凹部６に酸化膜が形成されている場合に、脚部２２，３２と半田との接合を確保しつつ抵抗体１０への半田の這い上がりを阻止できる。 In the present embodiment, the electrodes (first electrode body 11, second electrode body 12) project from the body portions 21 and 31 connected to the resistor 10 and the body portions 21 and 31 toward the substrate (circuit board). It has legs 22 and 32. As a result, when the oxide film is formed in the recess 6, it is possible to prevent the solder from creeping up to the resistor 10 while ensuring the bonding between the legs 22 and 32 and the solder.
　本実施形態において、抵抗体１０と、電極（第１電極体１１、第２電極体１２）と、を、それぞれの端面同士を突き合わせて接合する。これにより、抵抗体１０と抵抗体１０を挟み込む一対の電極（第１電極体１１、第２電極体１２）に構成されるので小型且つ低抵抗な抵抗器１が実現できる。 In the present embodiment, the resistor 10 and the electrodes (first electrode body 11, second electrode body 12) are joined so that their end faces are abutted against each other. As a result, a small and low resistance resistor 1 can be realized because it is composed of a pair of electrodes (first electrode body 11, second electrode body 12) that sandwich the resistor 10 and the resistor 10.
　本実施形態において、凹部６を、抵抗体１０から電極（第１電極体１１、第２電極体１２）に亘って形成する。これにより、トリミングを安定的に行うことができる。 In the present embodiment, the recess 6 is formed from the resistor 10 to the electrodes (first electrode body 11, second electrode body 12). Thereby, trimming can be performed stably.
　本実施形態に抵抗器１によれば、抵抗体１０と、抵抗体１０に接続された一対の電極（第１電極体１１、第２電極体１２）と、を備え、抵抗体１０の一部にトリミングを行うことにより抵抗値の調整が可能な抵抗器１であって、抵抗体１０と電極（第１電極体１１、第２電極体１２）の境界部位（接合部１３、接合部１４）における抵抗体１０にはトリミングとして凹部６が形成され、凹部６は、レーザ照射により形成されている。 According to the resistor 1 in the present embodiment, a resistor 10 and a pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10 are provided, and a part of the resistor 10 is provided. It is a resistor 1 whose resistance value can be adjusted by trimming the resistor 1, and is a boundary portion (joint portion 13, joint portion 14) between the resistor 10 and an electrode (first electrode body 11, second electrode body 12). A recess 6 is formed in the resistor 10 as trimming, and the recess 6 is formed by laser irradiation.
　上記構成により、電流投入時に抵抗体１０は発熱するが、抵抗体１０は抵抗体１０と電極（第１電極体１１、第２電極体１２）との境界部位（接合部１３、接合部１４）において最も温度が低い状態となる。よって、当該境界部位（接合部１３、接合部１４）にトリミングとして凹部６を形成することで、抵抗器１の熱分布の変化を低減しつつ抵抗値を調整することができる。また凹部６をレーザ照射により形成すると凹部６の内壁、又は凹部６の内壁及びその周縁に酸化膜が形成されるが、当該酸化膜は実装時の半田の這い上がりを阻止することができる。よって、抵抗体１０が半田に接触することを阻止して抵抗器１を用いた電流測定における検出精度の低下を回避することができる。 According to the above configuration, the resistor 10 generates heat when a current is applied, but the resistor 10 has a boundary portion (joint portion 13, joint portion 14) between the resistor 10 and the electrodes (first electrode body 11, second electrode body 12). Is the lowest temperature. Therefore, by forming the recess 6 as a trimming in the boundary portion (joint portion 13, joint portion 14), the resistance value can be adjusted while reducing the change in the heat distribution of the resistor 1. Further, when the recess 6 is formed by laser irradiation, an oxide film is formed on the inner wall of the recess 6, the inner wall of the recess 6, and the peripheral edge thereof, and the oxide film can prevent the solder from creeping up during mounting. Therefore, it is possible to prevent the resistor 10 from coming into contact with the solder and avoid a decrease in detection accuracy in the current measurement using the resistor 1.
　その他、本実施形態の抵抗器１は、以下のような構成・作用・効果を有する。 In addition, the resistor 1 of the present embodiment has the following configurations, actions, and effects.
　本実施形態の抵抗器１によれば、抵抗体１０と、抵抗体１０に接続された一対の電極（第１電極体１１、第２電極体１２）と、を備えた抵抗器１であって、抵抗体１０の端面と、電極の端面（第１電極体１１、第２電極体１２）とが、突き合わせて接合され、電極（第１電極体１１、第２電極体１２）は、胴体部２１，３１と胴体部２１，３１から実装面に突出した脚部２２，３２と、を含み、抵抗器１の長辺の長さ寸法は、３．２ｍｍ以下であり、抵抗値は２ｍΩ以下である。 According to the resistor 1 of the present embodiment, the resistor 1 includes the resistor 10 and a pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10. , The end face of the resistor 10 and the end face of the electrode (first electrode body 11, second electrode body 12) are butted and joined, and the electrode (first electrode body 11, second electrode body 12) is a body portion. Including 21, 31 and legs 22 and 32 protruding from the body portions 21 and 31 to the mounting surface, the length dimension of the long side of the resistor 1 is 3.2 mm or less, and the resistance value is 2 mΩ or less. be.
　上記構成により、抵抗体１０と抵抗体１０に接続された一対の電極（第１電極体１１、第２電極体１２）により胴体部２１，３１から実装面に突出した脚部２２，３２が構成される。これにより、検出端子からの引き出しが脚部２２，２３間で行えるため、小型の抵抗器１が実現できる。また、抵抗体１０の両端に電極（第１電極体１１、第２電極体１２）が接合された形態であり、抵抗体１０の（Ｘ方向の）寸法は抵抗器１の（Ｘ方向の）寸法よりも小さくなる。このため、抵抗体１０の下面に一対の電極を接合したタイプの抵抗器よりも低抵抗な抵抗器１を実現できる。以上より、小型化（長辺寸法３．２ｍｍ以下、３２１６サイズ以下）を実現しつつ一般的な抵抗器にはないさらなる低抵抗（２ｍΩ以下）を実現可能な抵抗器１となる。 With the above configuration, the resistor 10 and the pair of electrodes (first electrode body 11, second electrode body 12) connected to the resistor 10 constitute legs 22 and 32 protruding from the body portions 21 and 31 to the mounting surface. Will be done. As a result, the resistor 1 can be realized because it can be pulled out from the detection terminal between the legs 22 and 23. Further, electrodes (first electrode body 11, second electrode body 12) are joined to both ends of the resistor 10, and the dimensions (in the X direction) of the resistor 10 are (in the X direction) of the resistor 1. It is smaller than the dimension. Therefore, it is possible to realize a resistor 1 having a lower resistance than a type of resistor in which a pair of electrodes are bonded to the lower surface of the resistor 10. From the above, it becomes a resistor 1 that can realize a smaller resistance (2 mΩ or less) that is not found in general resistors while realizing miniaturization (long side dimension 3.2 mm or less, 3216 size or less).
　なお、抵抗体と電極体とを電子ビームなどにより溶接して形成された抵抗器であれば、このサイズでは抵抗値に当該溶接によるビードの影響を考慮する必要がある。しかし、本実施形態の抵抗器１は、後述のように、抵抗体１０と第１電極体１１、及び抵抗体１０と第２電極体１２とがそれぞれ拡散接合により接合可能であるため、このように小型に設計しても抵抗値等の特性を安定させることができる。 If the resistor is formed by welding the resistor and the electrode body with an electron beam or the like, it is necessary to consider the influence of the bead due to the welding on the resistance value at this size. However, in the resistor 1 of the present embodiment, as will be described later, the resistor 10 and the first electrode body 11 and the resistor 10 and the second electrode body 12 can be joined by diffusion bonding, respectively. Even if it is designed to be compact, characteristics such as resistance can be stabilized.
　本実施形態において、抵抗器１の実装面のうち、抵抗体１０と胴体部２１，３１との境界部位（接合部１３，１４）は平坦である。電子ビームなどの溶接による溶接ビードを有していないことにより、抵抗体１０と胴体部２１，３１との境界が明確になり、良否判断を容易に行うことができる。また、抵抗器１をシャント抵抗器として用いた場合、抵抗体１０と胴体部２１，３１との境界（接合部１３，１４）で段差が生じることにより発生する電流の検出精度の低下を抑制できる。更に、抵抗値、熱特性の安定性を向上させることができる。 In the present embodiment, of the mounting surface of the resistor 1, the boundary portion (joint portion 13, 14) between the resistor 10 and the body portions 21, 31 is flat. By not having a welding bead by welding such as an electron beam, the boundary between the resistor 10 and the body portions 21 and 31 becomes clear, and a good or bad judgment can be easily performed. Further, when the resistor 1 is used as a shunt resistor, it is possible to suppress a decrease in the detection accuracy of the current generated due to a step at the boundary (joint portions 13 and 14) between the resistor 10 and the body portions 21 and 31. .. Further, the stability of resistance value and thermal characteristics can be improved.
　本実施形態において、抵抗体１０と胴体部２１，３１とは固相接合により接合されている。これにより、抵抗体１０と第１電極体１１、及び抵抗体１０と第２電極体１２とが互いに強固に接合されるため、良好な電気的特性が得られる。また、抵抗器１では、抵抗体１０と第１電極体１１、及び抵抗体１０と第２電極体１２との接合には電子ビーム等の溶接が用いられていないため、接合部１３，１４には溶接ビード（凹凸形状の溶接痕）がない。したがって、抵抗器１の表面にワイヤーボンディング等を施す場合にボンディング性を損なうことがない。 In the present embodiment, the resistor 10 and the body portions 21 and 31 are joined by solid phase bonding. As a result, the resistor 10 and the first electrode body 11 and the resistor 10 and the second electrode body 12 are firmly bonded to each other, so that good electrical characteristics can be obtained. Further, in the resistor 1, since welding such as an electron beam is not used for joining the resistor 10 and the first electrode body 11 and the resistor 10 and the second electrode body 12, the joining portions 13 and 14 are joined. Has no welding beads (welded marks with uneven shape). Therefore, the bondability is not impaired when wire bonding or the like is applied to the surface of the resistor 1.
　本実施形態において、胴体部２１，３１は、抵抗体１０側に突出した突出部２１１，３１１を有する。これにより、抵抗器１の長手方向（Ｘ方向）の長さＬを一定としたとき、突出部２１１のＸ方向の長さＬ１（胴体部２１の長さ）、又は突出部３１１のＸ方向の長さＬ２（胴体部３１のＸ方向の長さ）を任意に調整し、抵抗体１０のＸ方向の長さＬ０をＬ０＝Ｌ－（Ｌ１＋Ｌ２）として調整することができる。したがって、脚部２２，３２の形状を変更することなく、抵抗器１の抵抗値を任意に調整することができる。 In the present embodiment, the body portions 21 and 31 have protruding portions 211 and 311 protruding toward the resistor 10. As a result, when the length L of the resistor 1 in the longitudinal direction (X direction) is constant, the length L1 of the protruding portion 211 in the X direction (the length of the body portion 21) or the length L of the protruding portion 311 in the X direction The length L2 (the length of the body portion 31 in the X direction) can be arbitrarily adjusted, and the length L0 of the resistor 10 in the X direction can be adjusted as L0 = L− (L1 + L2). Therefore, the resistance value of the resistor 1 can be arbitrarily adjusted without changing the shapes of the legs 22 and 32.
　本実施形態において、抵抗器１の抵抗体１０及び電極（第１電極体１１、第２電極体１２）の並び方向（Ｘ方向）における脚部２２，３２の実装面側の端部は、面取り形状となっている。 In the present embodiment, the ends of the legs 22 and 32 on the mounting surface side in the arrangement direction (X direction) of the resistor 10 of the resistor 1 and the electrodes (first electrode body 11, second electrode body 12) are chamfered. It has a shape.
　一般的な抵抗器では、面取りされていない角部分において電流密度が大となり、エレクトロマイグレーションと呼ばれる現象が発生したり、同様にして角部分に熱応力が集中したりすることにより、抵抗器の欠損が発生しやすくなっていた。また、このエレクトロマイグレーションは、回路サイズが微小化するにつれて無視できない影響を及ぼすため、抵抗器が小型になるほど、エレクトロマイグレーションが顕著化することが懸念されていた。 In a general resistor, the current density becomes high in the unchamfered corners, a phenomenon called electromigration occurs, and similarly, thermal stress concentrates in the corners, causing the resistor to become defective. Was more likely to occur. Further, since this electromigration has a non-negligible effect as the circuit size becomes smaller, there is a concern that the smaller the resistor, the more remarkable the electromigration becomes.
　これに対して、抵抗器１は、角部分Ｐが面取りされていることにより、角部分Ｐにおける電流密度の偏りが緩和される。これにより、エレクトロマイグレーションの発生を抑制することができる。また、同様にして、熱応力集中が緩和できるため、ヒートサイクル耐性を向上することができる。 On the other hand, in the resistor 1, since the corner portion P is chamfered, the bias of the current density in the corner portion P is alleviated. As a result, the occurrence of electromigration can be suppressed. Similarly, since the thermal stress concentration can be relaxed, the heat cycle resistance can be improved.
　本実施形態において、抵抗器１の抵抗体１０及び電極（第１電極体１１、第２電極体１２）の並び方向（Ｘ方向）及び抵抗器１の実装方向に垂直な方向（Ｚ方向）を幅方向（Ｙ方向）とし、抵抗体１０の表面、及び／又は、電極（第１電極体１１、第２電極体１２）の表面には幅方向（Ｙ方向）に沿って延びる筋状の凹凸面（筋状凹凸１５）が形成されている。これにより、抵抗器１の表面積を大きくして放熱性を高めることができ、また電極（第１電極体１１、第２電極体１２）に形成した場合は抵抗器１を回路基板に固定する半田の接合強度を高めることができる。 In the present embodiment, the alignment direction (X direction) of the resistor 10 and the electrodes (first electrode body 11, second electrode body 12) of the resistor 1 and the direction perpendicular to the mounting direction of the resistor 1 (Z direction) are set. In the width direction (Y direction), the surface of the resistor 10 and / or the surface of the electrodes (first electrode body 11, second electrode body 12) has streaky irregularities extending along the width direction (Y direction). A surface (streak-like unevenness 15) is formed. As a result, the surface area of the resistor 1 can be increased to improve heat dissipation, and when formed on the electrodes (first electrode body 11, second electrode body 12), solder for fixing the resistor 1 to the circuit board. It is possible to increase the joint strength of.
　本実施形態において、抵抗体１０は、直方体（又は立方体）に形成されている。抵抗体１０が直方体（又は直方体）であると、抵抗体１０の端面と略同形状に形成され、抵抗体１０の端面に接合された第１電極体１１及び第２電極体１２から抵抗体１０を流れる電流の経路が直線的になるため抵抗値を安定にすることができる。また、抵抗器１では、抵抗体１０が第１電極体１１と第２電極体１２の間に接合されているため、抵抗体１０の体積を必要最小限にして抵抗値を調整することが可能である。 In the present embodiment, the resistor 10 is formed in a rectangular parallelepiped (or a cube). When the resistor 10 is a rectangular body (or a rectangular body), the resistor 10 is formed from the first electrode body 11 and the second electrode body 12 which are formed in substantially the same shape as the end face of the resistor 10 and are joined to the end face of the resistor 10. Since the path of the current flowing through the is linear, the resistance value can be stabilized. Further, in the resistor 1, since the resistor 10 is joined between the first electrode body 11 and the second electrode body 12, the resistance value can be adjusted by minimizing the volume of the resistor 10. Is.
［抵抗器の製造方法の説明］
　図１０は、本実施形態の抵抗器１の製造方法を説明する模式図である。 [Explanation of how to manufacture resistors]
FIG. 10 is a schematic view illustrating a method for manufacturing the resistor 1 of the present embodiment.
　本実施形態の抵抗器１の製造方法は、材料を準備する工程（ａ）と、材料を接合する工程（ｂ）と、形状を加工する工程（ｃ）と、個々の抵抗器１に切断（個片化）する工程（ｄ）と、レーザを用いて抵抗器１の抵抗値を調整する工程（ｅ）とを備える。 The method for manufacturing the resistor 1 of the present embodiment includes a step of preparing the material (a), a step of joining the materials (b), a step of processing the shape (c), and cutting into individual resistors 1 ( It includes a step (d) of individualizing) and a step (e) of adjusting the resistance value of the resistor 1 using a laser.
　材料を準備する工程（ａ）では、抵抗体母材１０Ａと電極体母材１１Ａ，１２Ａを準備する。本実施形態では、抵抗器１のサイズ、抵抗値及び加工性の観点から、抵抗体母材１０Ａ（抵抗体１０）の材料として銅・マンガン・スズ系合金または銅・マンガン・ニッケル系合金を使用し、電極体母材１１Ａ，１２Ａ（第１電極体１１、第２電極体１２）の材料として無酸素銅（Ｃ１０２０）を使用することが好ましい。 In the step (a) of preparing the material, the resistor base material 10A and the electrode body base materials 11A and 12A are prepared. In this embodiment, a copper / manganese / tin alloy or a copper / manganese / nickel alloy is used as the material of the resistor base material 10A (resistor 10) from the viewpoint of the size, resistance value and workability of the resistor 1. However, it is preferable to use oxygen-free copper (C1020) as the material of the electrode body base materials 11A and 12A (first electrode body 11, second electrode body 12).
　材料を接合する工程（ｂ）では、電極体母材１１Ａと抵抗体母材１０Ａと電極体母材１２Ａとを、この順で重ね、重ね方向に圧力を加えて接合して抵抗器母材１００を形成する。 In the step (b) of joining the materials, the electrode body base material 11A, the resistor base material 10A, and the electrode body base material 12A are stacked in this order, and pressure is applied in the stacking direction to join the resistor base material 100. To form.
　すなわち、工程（ｂ）では、いわゆる異種金属材料間におけるクラッド接合（固相接合）が行われる。クラッド接合された電極体母材１１Ａと抵抗体母材１０Ａとの接合面、及び電極体母材１２Ａと抵抗体母材１０Ａとの接合面は、双方の金属原子が互いに拡散した拡散接合面となっている。 That is, in step (b), so-called clad bonding (solid phase bonding) between dissimilar metal materials is performed. The joint surface between the electrode body base material 11A and the resistor base material 10A that have been clad-bonded, and the joint surface between the electrode body base material 12A and the resistor base material 10A are the diffusion joint surfaces in which both metal atoms are diffused from each other. It has become.
　これにより、一般的な電子ビーム等による溶接を行うことなく、抵抗体母材１０Ａと電極体母材１１Ａとの接合面、及び抵抗体母材１０Ａと電極体母材１２Ａとの接合面を互いに強固に接合することができる。また、抵抗体母材１０Ａ（抵抗体１０）と電極体母材１１Ａ（第１電極体１１）との接合面及び抵抗体母材１０Ａ（抵抗体１０）と電極体母材１２Ａ（第２電極体１２）との接合面において、良好な電気的特性が得られる。 As a result, the joint surface between the resistor base material 10A and the electrode body base material 11A and the joint surface between the resistor base material 10A and the electrode body base material 12A can be brought into contact with each other without welding with a general electron beam or the like. Can be firmly joined. Further, the joint surface between the resistor base material 10A (resistor 10) and the electrode body base material 11A (first electrode body 11) and the resistor base material 10A (resistor body 10) and the electrode body base material 12A (second electrode) Good electrical characteristics can be obtained at the joint surface with the body 12).
　図１１は、本実施形態の抵抗器１の製造方法における形状を加工する工程（ｃ）を説明する模式図である。本実施形態では、工程（ｃ）において、ダイス３００が用いられる。工程（ｃ）では、クラッド接合によって得られた抵抗器母材１００をダイス３００に通過させる。 FIG. 11 is a schematic diagram illustrating a step (c) of processing a shape in the manufacturing method of the resistor 1 of the present embodiment. In the present embodiment, the die 300 is used in the step (c). In the step (c), the resistor base material 100 obtained by clad bonding is passed through the die 300.
　ダイス３００には、開口部３０１が形成されている。開口部３０１は、抵抗器母材１００が挿入可能な寸法に設定された入口開口３０２と、抵抗器母材１００の外形寸法よりも小さい寸法に設定された出口開口３０３と、入口開口３０２から出口開口３０３に向けてテーパ状に形成された挿通部３０４とを有する。 An opening 301 is formed in the die 300. The opening 301 has an inlet opening 302 set to a size into which the resistor base material 100 can be inserted, an outlet opening 303 set to a size smaller than the external dimension of the resistor base material 100, and an outlet from the inlet opening 302. It has an insertion portion 304 formed in a tapered shape toward the opening 303.
　このような形状のダイス３００に抵抗器母材１００を通過させることにより、抵抗器母材１００を全方向から圧縮変形させることができる。これにより抵抗器母材１００の断面形状はダイス３００（出口開口３０３）の外形に倣った形状となる。 By passing the resistor base material 100 through the die 300 having such a shape, the resistor base material 100 can be compressed and deformed from all directions. As a result, the cross-sectional shape of the resistor base material 100 becomes a shape that follows the outer shape of the die 300 (outlet opening 303).
　また、本実施形態では、工程（ｃ）において、抵抗器母材１００をダイス３００に通過させる際、抵抗器母材１００をつかみ具４００によって引き抜く、引き抜き工法が適用される。 Further, in the present embodiment, in the step (c), when the resistor base material 100 is passed through the die 300, the pull-out method is applied in which the resistor base material 100 is pulled out by the gripping tool 400.
　工程（ｃ）では、開口部３０１のサイズを異ならせた複数のダイス３００を用意して、これら複数のダイス３００を段階的に通過させる引き抜き加工を施してもよい。 In the step (c), a plurality of dies 300 having different sizes of the openings 301 may be prepared and subjected to a drawing process in which the plurality of dies 300 are passed in stages.
　また、工程（ｃ）では、ダイス３００の開口部３０１の形状を変更することにより、本実施形態の抵抗器１を製造することができる。 Further, in the step (c), the resistor 1 of the present embodiment can be manufactured by changing the shape of the opening 301 of the die 300.
　抵抗器１を製造するにあたっては、一例として、開口部３０１（入口開口３０２、出口開口３０３）の一の辺における一部に、開口中央に向けて矩形に突出した形状を有するダイス３００を適用する。抵抗器母材１００には、矩形形状の出口開口３０３に設けられた突出形状により、引き抜き方向に連続する矩形溝１０５が形成される。 In manufacturing the resistor 1, as an example, a die 300 having a shape protruding rectangularly toward the center of the opening is applied to a part of one side of the opening 301 (inlet opening 302, outlet opening 303). .. In the resistor base material 100, a rectangular groove 105 continuous in the pulling direction is formed by the protruding shape provided in the rectangular outlet opening 303.
　抵抗器母材１００を個々に切断した際に、この矩形溝１０５は、抵抗体１０と第１電極体１１の胴体部２１と脚部２２、第２電極体１２の胴体部３１と脚部３２によって囲まれる凹部を構成する。 When the resistor base material 100 is individually cut, the rectangular groove 105 forms the body portion 21 and the leg portion 22 of the resistor 10 and the first electrode body 11, and the body portion 31 and the leg portion 32 of the second electrode body 12. Consists of a recess surrounded by.
　図１０に戻り、工程（ｃ）に続く工程（ｄ）では、設計されたＹ方向の長さＷになるように、抵抗器母材１００から抵抗器１を切り出す。また、本実施形態では、工程（ｄ）において、抵抗器母材１００において矩形溝１０５が形成された面１００ａ（抵抗器１の実装面）から反対面１００ｂ（抵抗器１の上面）に向けて切断することが好ましい。これにより、金属のバリ（Ｂｕｒｒ）は抵抗器１の上面から上方に向けて延びる形に形成され、脚部２２，３２において－Ｚ方向（図１、図２）に延びるバリ（回路基板に向けて延びるバリ）が発生することはない。これにより、抵抗器１の回路基板への実装を確実に行うことができる。 Returning to FIG. 10, in the step (d) following the step (c), the resistor 1 is cut out from the resistor base material 100 so as to have the designed length W in the Y direction. Further, in the present embodiment, in the step (d), from the surface 100a (mounting surface of the resistor 1) on which the rectangular groove 105 is formed in the resistor base material 100 to the opposite surface 100b (upper surface of the resistor 1). It is preferable to cut. As a result, the metal burr is formed so as to extend upward from the upper surface of the resistor 1, and the burr (toward the circuit board) extending in the −Z direction (FIGS. 1 and 2) at the legs 22 and 32. Burrs that extend) do not occur. As a result, the resistor 1 can be reliably mounted on the circuit board.
　以上の工程を経ることにより、抵抗器母材１００から個片の抵抗器１を得ることができる。更に、工程（ｅ）では、レーザ照射により抵抗体１０のトリミングを行って抵抗器１の抵抗値を所望の抵抗値に設定する。トリミングの詳細については上記の通りである（図８乃至図１０参照）。なお、図１、２に示す、角部分Ｐはダイス３００の開口部３０１の形状に倣って形成され、筋状凹凸１５は抵抗器母材１００がダイス３００の内壁（出口開口３０３）に圧接した状態で摺動するときに形成される筋状の摺動痕である。 By going through the above steps, a piece of resistor 1 can be obtained from the resistor base material 100. Further, in the step (e), the resistor 10 is trimmed by laser irradiation to set the resistance value of the resistor 1 to a desired resistance value. The details of trimming are as described above (see FIGS. 8 to 10). In addition, the corner portion P shown in FIGS. It is a streak-like sliding mark formed when sliding in a state.
　＜本実施形態のダイス３００を用いた抵抗器１の製造方法の効果＞
　次に、本実施形態の作用効果について説明する。 <Effect of the method for manufacturing the resistor 1 using the die 300 of the present embodiment>
Next, the action and effect of this embodiment will be described.
　本実施形態のダイス３００を用いた抵抗器１の製造方法によれば、電極体母材１１Ａと抵抗体母材１０Ａと電極体母材１２Ａとを重ねて圧力を加えて、クラッド接合（固相接合）により一体化する。これにより、電子ビームによる溶接等を用いること無く、抵抗体母材１０Ａ（抵抗体１０）と電極体母材１１Ａ（第１電極体１１）の接合強度、及び抵抗体母材１０Ａ（抵抗体１０）と電極体母材１２Ａ（第２電極体１２）の接合強度を高めることができる。 According to the method for manufacturing the resistor 1 using the die 300 of the present embodiment, the electrode body base material 11A, the resistor base material 10A, and the electrode body base material 12A are overlapped and pressure is applied to perform clad bonding (solid phase). It is integrated by joining). As a result, the bonding strength between the resistor base material 10A (resistor 10) and the electrode body base material 11A (first electrode body 11) and the resistor base material 10A (resistor body 10) can be achieved without using welding with an electron beam or the like. ) And the electrode body base material 12A (second electrode body 12) can be increased.
　また、本実施形態の上記製造方法によれば、抵抗器母材１００をダイス３００に通して全方向から圧縮することにより、抵抗器母材１００の外形状を成型することができる。このため、抵抗器母材１００が形成された後は、工程（ｄ）を経るだけで個別の抵抗器１を製造できる。したがって、抵抗器１の製造によって生じる個体差を抑えることができる。また、これに加えて、抵抗器母材１００をダイス３００に通すことにより、抵抗体１０と第１電極体１１との接合強度、及び抵抗体１０と第２電極体１２との接合強度を更に高めることができる。 Further, according to the above-mentioned manufacturing method of the present embodiment, the outer shape of the resistor base material 100 can be molded by passing the resistor base material 100 through the die 300 and compressing it from all directions. Therefore, after the resistor base material 100 is formed, the individual resistor 1 can be manufactured only by going through the step (d). Therefore, individual differences caused by the manufacture of the resistor 1 can be suppressed. In addition to this, by passing the resistor base material 100 through the die 300, the bonding strength between the resistor 10 and the first electrode body 11 and the bonding strength between the resistor 10 and the second electrode body 12 are further increased. Can be enhanced.
　抵抗器母材１００を全方向から圧縮する方法としては、例えば、抵抗器母材１００が方形であれば、抵抗器母材１００を厚み方向（Ｚ）から加圧する一対のローラによって第１段の圧接を施して、その後、幅方向（Ｙ）から加圧する一対のローラによって第２段の圧接を施す方法がある。 As a method of compressing the resistor base material 100 from all directions, for example, if the resistor base material 100 is square, the first stage is performed by a pair of rollers that pressurize the resistor base material 100 from the thickness direction (Z). There is a method in which pressure welding is performed and then pressure welding is performed in the second stage by a pair of rollers that pressurize from the width direction (Y).
　しかし、この方法では、第１段の圧接工程において、抵抗器母材１００は、厚み方向Ｚに圧縮されるものの、幅方向（Ｙ）には膨張してしまう。また、続く第２段の圧接工程において、抵抗器母材１００は、幅方向Ｙに圧縮されるものの、厚み方向（Ｚ）には膨張してしまう。この結果、寸法精度が低下し、個々の抵抗器のばらつきや抵抗器への電力印加時の温度分布のばらつき等が大きくなってしまう。 However, in this method, in the first-stage pressure welding step, the resistor base material 100 is compressed in the thickness direction Z, but expands in the width direction (Y). Further, in the subsequent pressure welding step of the second stage, the resistor base material 100 is compressed in the width direction Y, but expands in the thickness direction (Z). As a result, the dimensional accuracy is lowered, and the variation of individual resistors and the variation of temperature distribution when power is applied to the resistors become large.
　これに対して、本実施形態の上記製造方法によれば、抵抗器母材１００をダイス３００に通過させる引き抜き工程を行うことにより、抵抗器母材１００を長さ方向（Ｘ）及び厚み方向（Ｚ）に一様に圧縮できる。 On the other hand, according to the above-mentioned manufacturing method of the present embodiment, the resistor base material 100 is pulled out through the die 300 to allow the resistor base material 100 to pass in the length direction (X) and the thickness direction (X). It can be uniformly compressed to Z).
　このため、ローラを用いて一方向からの圧縮と他方向からの圧縮とを繰り返すことで得られた抵抗器母材に比べて、抵抗器母材１００は、電気的に有利な接合界面が形成されると考えられる。したがって、完成品としての抵抗器１の特性差を抑えることができる。 Therefore, the resistor base material 100 forms an electrically advantageous bonding interface as compared with the resistor base material obtained by repeating compression from one direction and compression from the other direction using a roller. It is thought that it will be done. Therefore, it is possible to suppress the characteristic difference of the resistor 1 as a finished product.
　本実施形態の上記製造方法では、特に、開口部３０１の異なる複数のダイス３００を段階的に用いて、抵抗器母材１００のサイズを段階的に小さくなるように圧縮成型することにより、抵抗器母材１００やダイス３００への負荷を低減しつつ、抵抗器母材１００を長さ方向（Ｘ）及び厚み方向（Ｚ）に一様に圧縮できる。これにより、完成品としての抵抗器１の特性のバラツキを抑えることができる。 In the above-mentioned manufacturing method of the present embodiment, in particular, a plurality of dies 300 having different openings 301 are used stepwise, and the size of the resistor base material 100 is compression-molded so as to be stepwise reduced. While reducing the load on the base material 100 and the die 300, the resistor base material 100 can be uniformly compressed in the length direction (X) and the thickness direction (Z). As a result, it is possible to suppress variations in the characteristics of the resistor 1 as a finished product.
　また、本実施形態の上記製造方法では、抵抗器母材１００をダイス３００に通す工程（ｃ）において、引き抜き工程が適用されることにより、押し出し工法に比べて完成品の精度が高められる。この製造方法を用いることにより、抵抗器１としての特性の安定化を実現できる。 Further, in the above-mentioned manufacturing method of the present embodiment, the accuracy of the finished product is improved as compared with the extrusion method by applying the drawing step in the step (c) of passing the resistor base material 100 through the die 300. By using this manufacturing method, it is possible to realize stabilization of the characteristics of the resistor 1.
　特に、ダイス３００の開口部３０１の、少なくとも出口開口３０３は曲線により連続して形成されている。これにより、抵抗器母材１００が開口を通過する際に抵抗器母材１００に印加される応力を緩和することができ、抵抗器母材１００やダイス３００への負荷を低減することができる。これにより、完成品としての抵抗器１の特性のバラツキを抑えることができる。 In particular, at least the outlet opening 303 of the opening 301 of the die 300 is continuously formed by a curved line. As a result, the stress applied to the resistor base material 100 when the resistor base material 100 passes through the opening can be relaxed, and the load on the resistor base material 100 and the die 300 can be reduced. As a result, it is possible to suppress variations in the characteristics of the resistor 1 as a finished product.
　これに加え、少なくとも出口開口３０３は曲線により連続して形成されているので、ダイス３００を通過して得られた抵抗器１の角部分は面取りされることになる。これにより、角部分Ｐにおいて抵抗器１に生じるエレクトロマイグレーションを抑制することができる。また、抵抗器１のヒートサイクル耐性を高めることができる。 In addition to this, since at least the outlet opening 303 is continuously formed by a curved line, the corner portion of the resistor 1 obtained by passing through the die 300 is chamfered. As a result, the electromigration that occurs in the resistor 1 at the corner portion P can be suppressed. In addition, the heat cycle resistance of the resistor 1 can be increased.
　また、本実施形態の上記製造方法によれば、第１電極体１１と抵抗体１０と第２電極体１２とが互いに拡散接合（固相接合）により接合されているため、溶接ビードがない。一般的な電子ビーム等を用いた溶接による接合では、抵抗器が小型化されるにつれて溶接ビードが抵抗値特性に無視できない影響を与えることがあった。しかし、本実施形態の上記製造方法によって得られた抵抗器１には、その懸念がない。 Further, according to the above-mentioned manufacturing method of the present embodiment, since the first electrode body 11, the resistor 10, and the second electrode body 12 are bonded to each other by diffusion bonding (solid phase bonding), there is no welding bead. In joining by welding using a general electron beam or the like, the welding bead may have a non-negligible effect on the resistance value characteristics as the resistor becomes smaller. However, the resistor 1 obtained by the above-mentioned manufacturing method of the present embodiment does not have such a concern.
　このように、本実施形態の上記製造方法は、抵抗体母材１０Ａ及び電極体母材１１Ａ，１２Ａをクラッド接合（固相接合）して得られる抵抗器母材１００をダイス３００に通して成型する。このため、電子ビーム等による溶接を用いなくとも材料間の接合強度を高めることが可能であり、高い寸法精度を確保することができるため、小型の抵抗器１の製造に好適である。 As described above, in the above manufacturing method of the present embodiment, the resistor base material 100 obtained by clad bonding (solid phase bonding) the resistor base material 10A and the electrode body base materials 11A and 12A is passed through a die 300 and molded. do. Therefore, it is possible to increase the bonding strength between materials without using welding with an electron beam or the like, and it is possible to secure high dimensional accuracy, which is suitable for manufacturing a small resistor 1.
　抵抗器１を製造するにあたって、工程（ｄ）では、抵抗器母材１００において矩形溝１０５が形成された面１００ａから反対面１００ｂに向けて切断することが好ましい。これにより、切断によって生じるバリを、実装面側の溝（凹部）の空間に収めることができる。 In manufacturing the resistor 1, in the step (d), it is preferable to cut the resistor base material 100 from the surface 100a on which the rectangular groove 105 is formed toward the opposite surface 100b. As a result, burrs generated by cutting can be accommodated in the space of the groove (recess) on the mounting surface side.
　また、本実施形態の上記製造方法において、形状を加工する工程（ｃ）の前段に、クラッド接合された抵抗器母材１００のサイズをダイス３００に挿通可能なサイズに調整する工程が含まれていてもよい。 Further, in the above-mentioned manufacturing method of the present embodiment, a step of adjusting the size of the clad-bonded resistor base material 100 to a size that can be inserted into the die 300 is included in the first stage of the step (c) of processing the shape. You may.
　また、本実施形態の上記製造方法において、酸化膜の形成にレーザ照射を用いるとしたが、金属表面を改質させた酸化膜が形成できればレーザに限定するものではなく、例えば酸化剤を供給することにより酸化膜を形成してもよい。 Further, in the above-mentioned production method of the present embodiment, laser irradiation is used for forming an oxide film, but the present invention is not limited to a laser as long as an oxide film having a modified metal surface can be formed, and for example, an oxidizing agent is supplied. As a result, an oxide film may be formed.
　以上、本発明の実施形態について説明したが、上記実施形態は本発明の適用例の一部を示したに過ぎず、本発明の技術的範囲を上記実施形態の具体的構成に限定する趣旨ではない。例えば、本実施形態では抵抗器母材１００をダイス３００に通して個片化した抵抗器１について説明したが、ダイス３００を通すことなく抵抗体と電極体とをクラッド接合した抵抗器や、プレス加工により成型された抵抗器にも適用できる。 Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. do not have. For example, in the present embodiment, the resistor 1 in which the resistor base material 100 is passed through the die 300 and separated into individual pieces has been described, but a resistor in which the resistor and the electrode body are clad-bonded without passing through the die 300, or a press. It can also be applied to resistors molded by processing.
　本実施形態において、抵抗体１０は、直方体であったが、例えば＋Ｚ方向（図1参照）に向かうにつれてＸ方向（図１参照）の長さが短くなる台形形状でもよい。また、本実施形態は、例えば抵抗体１０の実装面においてＸ方向の両端に電極を接合した抵抗器にも適用でき、このとき凹部６は一対の電極の間に一対で形成するが、Ｘ方向で対称となるようにそれぞれ電極近傍に形成すればよい。さらに、凹部６（６ａ－６ｆ）は、Ｙ方向に端から端まで到達する態様で形成しなくてもよい。この場合であっても熱分布の変化を抑制することができる。 In the present embodiment, the resistor 10 is a rectangular parallelepiped, but may have a trapezoidal shape in which the length in the X direction (see FIG. 1) becomes shorter toward the + Z direction (see FIG. 1). Further, the present embodiment can also be applied to a resistor in which electrodes are joined to both ends in the X direction on the mounting surface of the resistor 10, for example. At this time, the recesses 6 are formed in pairs between the pair of electrodes, but in the X direction. It may be formed in the vicinity of the electrodes so as to be symmetrical with each other. Further, the recess 6 (6a-6f) does not have to be formed so as to reach from end to end in the Y direction. Even in this case, the change in heat distribution can be suppressed.
　本願は、２０２０年１月２７日に日本国特許庁に出願された特願２０２０－０１１１９８に基づく優先権を主張し、この出願の全ての内容は参照により本明細書に組み込まれる。 The present application claims priority based on Japanese Patent Application No. 2020-011198 filed with the Japan Patent Office on January 27, 2020, and the entire contents of this application are incorporated herein by reference.
１　　抵抗器
１０　抵抗体
１１　第１電極体
１２　第２電極体
１３　接合部
１４　接合部
６　　凹部 1 Resistor 10 Resistor 11 1st electrode body 12 2nd electrode body 13 Joint 14 Joint 6 Recess

Claims (6)

  1. 　抵抗体と、前記抵抗体に接続された一対の電極と、を備え、前記抵抗体の一部にトリミングを行うことにより抵抗値の調整が可能な抵抗器の製造方法であって、
    　前記抵抗体と前記電極の境界部位における前記抵抗体に前記トリミングとして凹部を形成する抵抗器の製造方法。     A method for manufacturing a resistor, which comprises a resistor and a pair of electrodes connected to the resistor, and the resistance value can be adjusted by trimming a part of the resistor.
    A method for manufacturing a resistor in which a recess is formed as a trimming in the resistor at a boundary portion between the resistor and the electrode.
  2. 　請求項１に記載の抵抗器の製造方法であって、
    　前記凹部を、前記抵抗体及び一対の前記電極が共に基板に対向する向きで前記基板に実装する際の前記抵抗器の実装面に形成する抵抗器の製造方法。     The method for manufacturing a resistor according to claim 1.
    A method for manufacturing a resistor, in which the recess is formed on a mounting surface of the resistor when the resistor and the pair of electrodes are both mounted on the substrate in a direction facing the substrate.
  3. 　請求項２に記載の抵抗器の製造方法であって、
    　前記電極は、前記抵抗体に接続する胴体部と、前記胴体部から前記基板の方向に突出した脚部とを有する抵抗器の製造方法。     The method for manufacturing a resistor according to claim 2.
    A method for manufacturing a resistor, wherein the electrode has a body portion connected to the resistor and a leg portion protruding from the body portion in the direction of the substrate.
  4. 　請求項１乃至３のいずれか１項に記載の抵抗器の製造方法であって、
    　前記抵抗体と、前記電極と、を、それぞれの端面同士を突き合わせて接合する抵抗器の製造方法。     The method for manufacturing a resistor according to any one of claims 1 to 3.
    A method for manufacturing a resistor in which the resistor and the electrode are joined by abutting their end faces against each other.
  5. 　請求項１乃至４のいずれか１項に記載の抵抗器の製造方法であって、
    　前記凹部を、前記抵抗体から前記電極に亘って形成する抵抗器の製造方法。     The method for manufacturing a resistor according to any one of claims 1 to 4.
    A method for manufacturing a resistor in which the recess is formed from the resistor to the electrode.
  6. 　抵抗体と、前記抵抗体に接続された一対の電極と、を備え、前記抵抗体の一部にトリミングを行うことにより抵抗値の調整が可能な抵抗器であって、
    　前記抵抗体と前記電極の境界部位における前記抵抗体には前記トリミングとして凹部が形成され、
    　前記凹部は、レーザ照射により形成されている抵抗器。     A resistor provided with a resistor and a pair of electrodes connected to the resistor, and the resistance value can be adjusted by trimming a part of the resistor.
    A recess is formed in the resistor at the boundary between the resistor and the electrode as the trimming.
    The recess is a resistor formed by laser irradiation.
PCT/JP2020/049196 2020-01-27 2020-12-28 Manufacturing method for resistor, and resistor WO2021153153A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56119602U (en) * 1980-02-14 1981-09-11
JPH01209703A (en) * 1988-02-18 1989-08-23 Mitsubishi Electric Corp Resistance value control apparatus of thick film resistor
JPH11162720A (en) * 1997-11-21 1999-06-18 Hokuriku Electric Ind Co Ltd Chip resistor and its adjusting method
JP2008512872A (en) * 2004-09-13 2008-04-24 エレクトロ サイエンティフィック インダストリーズ インコーポレーテッド Analysis method of thermoelectric potential during laser trimming to resistor
JP2015065197A (en) * 2013-09-24 2015-04-09 コーア株式会社 Jumper element or resistance element for current detection

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56119602U (en) * 1980-02-14 1981-09-11
JPH01209703A (en) * 1988-02-18 1989-08-23 Mitsubishi Electric Corp Resistance value control apparatus of thick film resistor
JPH11162720A (en) * 1997-11-21 1999-06-18 Hokuriku Electric Ind Co Ltd Chip resistor and its adjusting method
JP2008512872A (en) * 2004-09-13 2008-04-24 エレクトロ サイエンティフィック インダストリーズ インコーポレーテッド Analysis method of thermoelectric potential during laser trimming to resistor
JP2015065197A (en) * 2013-09-24 2015-04-09 コーア株式会社 Jumper element or resistance element for current detection

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