JP-7856513-B2 - Resistor component, method for manufacturing a resistor component, and resistor

Inventors

• 森田 明
• 菅原 親人
• 安岡 知道
• 吉崎 達也
• 梅野 和行
• 三原 邦照

Assignees

• 古河電気工業株式会社

Dates

Publication Date

20260511

Application Date

20220712

Claims (7)

1. A resistor member comprising a first metal member and a second metal member joined together via a joint, The first metal member contains 99.96% by mass or more of Cu, The second metal member contains Cu in an amount of 83.00% by mass or more and 94.00% by mass or less. In a cross-section perpendicular to the weld line, if the first joint width of the joint on the first surface of the joint is w1, the second joint width of the joint on the second surface of the joint facing the first surface is w2, and the intermediate thickness joint width of the joint located midway between the first and second surfaces is w, then the joint width ratio (w1/w) is 1.70 or more and 2.30 or less, and the joint width ratio (w2/w) is 0.60 or more and 1.15 or less. Resistor components.
2. The resistor member has a bent portion, The resistor member according to claim 1, wherein the bent portion is bent with the first surface of the joint portion as the outer surface of the bent portion, and the bending center position is within 5.0 mm from the middle of the joint width of the joint portion in the cross section.
3. The resistor member has a bent portion, The resistor member according to claim 1, wherein the bending radius on the inner surface side of the bent portion is 0.5 times or more the thickness of the first metal member.
4. The resistor component according to claim 1, wherein the second metal component is a copper alloy having an alloy composition containing 10.00% by mass or more and 13.00% by mass or less of Mn, and 1.50% by mass or more and 3.00% by mass or less of Ni, with the remainder being Cu and unavoidable impurities.
5. The resistor component according to claim 1, wherein the second metal component is a copper alloy having an alloy composition containing 6.00% by mass or more and 8.00% by mass or less of Mn, and 1.00% by mass or more and 4.00% by mass or less of Sn, with the remainder being Cu and unavoidable impurities.
6. A method for manufacturing a resistor component according to any one of claims 1 to 5, comprising a bonding step of joining a first metal component and a second metal component using a fiber laser.
7. A resistor using the resistor component described in any one of claims 1 to 5.

Description

This disclosure relates to resistor components, methods for manufacturing resistor components, and resistors. In recent years, as material requirements have increased year by year, there has been a growing need to join metals with conflicting properties. For example, in the field of heat exchangers, materials with high thermal conductivity, such as copper, copper alloys, aluminum, and aluminum alloys, are combined with materials with high heat resistance, such as stainless steel and heat-resistant steel. Furthermore, in other fields, there is a high demand for joining various types of metal plates, such as combining heavy materials like copper and copper alloys with lighter materials like aluminum and aluminum alloys. Furthermore, there are many examples of this already being used in practice. Bimetallic strips are made by joining materials with different coefficients of thermal expansion. Shunt resistors, on the other hand, incorporate resistor components that join low-resistance materials (e.g., pure copper) and high-resistance materials (e.g., resistance alloys). There are various methods for joining materials with opposing properties, including fusion welding, solid-state bonding, brazing, adhesive bonding, and mechanical bonding. Among these, fusion welding has been used for a long time, and is practical and has a proven track record. Fusion welding methods include arc welding (represented by TIG welding, MIG/MAG welding, and plasma welding), spot welding, seam welding, projection welding, resistance welding (represented by flash butt welding), and high-energy beam welding (represented by laser beam welding and electron beam welding). Among these methods, laser beam welding is a welding technique that uses laser light as a heat source, primarily focusing it onto metal to locally melt and solidify it. Laser beam welding utilizes high energy density to enable welding in a short time, and in recent years, the functionality of laser welding light sources has advanced, such as in fiber laser welding. Because laser light is a single-wavelength, phase-free light, it can be focused into an extremely small point using the lens of the optical system to obtain high-density energy. Therefore, it has the advantage of allowing for very narrow joint widths. However, in fiber laser welding, due to the characteristics of the laser, even slight changes in joining conditions can reduce the joint strength. This makes the joint surface more susceptible to cracking when bending stress is applied. Such problems associated with bending are issues that need to be addressed for resistor components. Furthermore, Patent Document 1 describes a shunt resistor in which a portion of the base material is cut and a portion of the cut material is bent, with the aim of suppressing heat generation. Patent Document 2 describes a shunt resistor in which the electrodes are bent, with the aim of stabilizing the resistance value. Patent Document 3 describes a shunt resistor in which a string pattern is created on the surface of the resistive alloy material by laser processing, with the aim of reliably indicating the set resistance value to the user. Here, the bendability of the joint surface is an important indicator for evaluating welding quality, and its evaluation method is specified and standardized in JIS Z 3122, "Bending Test Method for Butt Welded Joints." On the other hand, Patent Documents 1 to 3 do not mention any techniques or studies for improving the bendability of resistor components constituting shunt resistors. Furthermore, in recent years, with the downsizing of electronic devices, the shape of shunt resistors has become more complex, and the demand for shunt resistors with bent processing has increased. Moreover, the required standards for the accuracy of electrical resistance values and long-term performance reliability are rising year by year. Cracks on the joint surface not only affect the electrical resistance value, but vibration and shock can cause these cracks to spread, potentially leading to abnormal increases in electrical resistance or loss of function. Therefore, the absence of cracks on the joint surface is required. In addition, resistor components are required to suppress burrs generated on the joint surface and to reduce the rate of change in resistance value due to temperature changes. Japanese Patent Publication No. 2019-91824Japanese Patent Publication No. 2018-18960International Publication No. 2016/175016 Figure 1 is a perspective view showing an example of a resistor component according to an embodiment.Figure 2 is an enlarged cross-sectional view showing an example of a resistor component of the embodiment.Figure 3 is a cross-sectional view showing another example of a resistor component of the embodiment.Figure 4 shows the results of observing a cross-section perpendicular to the weld line of the resistor component of Example 1 using a microscope. The embodiments will be described in detail below. As a