JP2001116771A - Low resistance resistor for current detection and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low resistance resistor for current detection capable of simplifying a manufacturing process, lessening the number of parts, reducing a manufacturing cost and excellent in heat radiation. SOLUTION: On the low resistance resistor 1 for the current measuring, the center part of a rectangular metal-made low resistance resistor 2 is pushed and bent toward the surface side, and the upper part is projected in a flat crest form. The center part of a rise part on both the surface ends of the metal- made low resistance resistor 2 performs copper plating, further nickel plating is performed thereon, and a pair of bonding electrode pads 3, 3 are formed. Copper plating, nickel plating and soldering plating are successively performed, and a pair of connection electrodes 4, 4 are formed on a printed board or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current detecting low resistor and a method of manufacturing the same, and more particularly to a current detecting low resistor having an electrode for connecting to an external circuit by wire bonding and a method of manufacturing the same. .

[0002]

2. Description of the Related Art Conventionally, as a low resistor for current detection, one having a structure as shown in FIG. 7 is known. This is because a low-resistance metal plate 41 made of a manganin plate or the like and a copper plate 42 for heat dissipation are laminated with an alumina plate 43 serving as an insulator interposed therebetween, and the copper plate 42 on the back side is used for bonding to a printed board or the like. Gold plated layer 44 is formed. On the other hand, both ends of the surface of the metal low-resistance body 41 are plated with nickel to form a pair of bonding electrode pads 45.

[0003] Such a current detecting low resistor is mounted on a printed circuit board or the like via a gold plating layer 44, and wire bonding is performed on a pair of electrode pads 45, and the current flowing through the metal low resistor 41 is detected. The size can be measured.

[0004] This current detecting low resistor is manufactured as follows. That is, first, the sheet-shaped heat-dissipating copper plate 4
2, the alumina plate 43, and the metal low-resistance body 41 are laminated in this order to form a three-layer, multi-cavity laminate. Next, a resist is applied on the copper plate 2 and patterned to form a resist pattern on the portion to be cut. Then, gold plating is applied to portions other than the portion to be cut, and then the resist pattern is peeled off and separated by the portion to be cut. The gold plating layers 44 thus arranged are arranged in a matrix. Next, a resist is applied to the surface of the metal low-resistance body 41, and patterning is performed to form a resist pattern having openings in a pair of electrode pad planned portions. Then, the opening is plated with nickel, and then the resist pattern is peeled off. Thus, a pair of electrode pads 45 are formed in a matrix.

[0005] Next, a resist is applied to the surface of the metal low-resistance body 41, patterning is performed to form a resist pattern in a portion other than the portion to be cut, and then etching is performed to remove the metal low-resistance in the portion to be cut. The body 41 is removed. Thereafter, the resist pattern is peeled off to form a cutting groove for dividing the sheet-shaped multi-piece substrate into individual resistors. Next, after a resist pattern is formed on the copper plate 42 on the rear surface side in a portion other than the portion to be cut in the same manner, etching is performed to remove the copper plate 42 at the portion to be cut. Thereafter, the resist pattern is peeled off to form a cutting groove for dividing the sheet-shaped multi-piece substrate into individual resistors. Next, trimming adjustment of each metal low-resistance body 41 is performed by a laser or the like. Next, cutting is performed along the cutting grooves to obtain individual chip-shaped low resistors.

[0006]

However, the conventional low resistance for current measurement has a problem that the manufacturing process is complicated and the number of parts is large, so that the manufacturing cost is high. In addition, since the alumina plate is interposed, there is a problem that heat radiation is necessarily inferior. Also,
There is a problem that the accuracy of measuring the resistance value varies during wire bonding of the electrodes.

The present invention has been made in view of the above circumstances, and has a simple manufacturing process, a small number of parts, a low manufacturing cost, and a current detecting low resistor excellent in heat dissipation. It is an object of the present invention to provide a manufacturing method thereof.

[0008]

According to a first aspect of the present invention, there is provided a current detecting low resistor according to the first aspect, wherein a central portion of a plate-shaped metal low resistor is protruded to the front side, and A pair of bonding electrode pads are formed at both ends, and a pair of connection electrodes are formed at both ends of the back surface.

[0009] This makes it possible to press the plate-shaped metal low-resistance material and form a pair of electrode pads and a pair of connection electrodes on the front and back surfaces, respectively. It is simple and made of a metal low-resistance material plate, so that the number of parts is small. Therefore, manufacturing costs can be reduced. Further, since it is formed of a metal low-resistance material, it has excellent heat dissipation.

According to a second aspect of the present invention, there is provided a method for manufacturing a low-resistance resistor for current detection, wherein a resist pattern is formed on each of the front and back surfaces of a plate-shaped low-resistance metal material, and then electrolytic plating is applied to the front surface side. A pair of electrode pads and a pair of connection electrodes are formed on the back side, and a portion between the pair of electrode pads in the metal low-resistance material is projected to the front side by press working. Thus, the current detection low resistor can be easily manufactured by performing electrolytic plating using the resist pattern and press working.

According to a third aspect of the present invention, there is provided a method of manufacturing a low-resistance resistor for current detection, wherein a plating film mask is applied to each of the front and rear surfaces of a plate-shaped metal low-resistance material, and then the surface is subjected to electrolytic plating. Forming a pair of electrode pads on the side and a pair of connection electrodes on the back side, and projecting a portion between the pair of electrode pads in the metal low-resistance material to the front side by pressing. . Thus, the current detection low resistor can be easily manufactured by applying the electrolytic plating using the plating film mask and pressing.

According to a fourth aspect of the present invention, there is provided a current detecting low resistor.
It is characterized by being formed by applying copper plating and further applying nickel plating. Thereby, since the copper plating is performed, the accuracy of the variation in the resistance value is improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the current measuring low-resistance 1 according to the present embodiment includes a rectangular metal low-resistance body 2 made of a manganin plate, a copper-nickel plate, a nickel-chrome plate, or the like. The central part is pressed and bent toward the surface side, and the upper part is projected in a flat mountain shape. Copper plating is applied to the center portion on the rising portion side at both end portions of the surface of the metal low-resistance body 2, and further, nickel plating is applied to form a pair of bonding electrode pads 3.
3 are formed. Further, a pair of electrodes 4 and 4 for connection to a printed board or the like are formed by sequentially applying copper plating, nickel plating, and solder plating to both ends of the rear surface of the metal low-resistance element 2.

The current detecting low resistor 1 is mounted on a printed circuit board or the like, and a current terminal is connected to the pair of electrodes 4 and 4. On the other hand, a wire bonding for measuring the sense voltage is performed on the pair of electrode pads 3 and 3, and the voltage between them can be measured as the sense voltage. Thereby, the magnitude of the current flowing through the metal low-resistance body 1 can be measured.

In the current detection low resistor 1, a plate-shaped metal low resistance material is pressed to bend the center portion upward, and a pair of electrode pads 3 and 3 are formed on the front and back surfaces, respectively. Since it can be manufactured by forming the pair of connection electrodes 4 and 4, the manufacturing process can be simplified. In addition, since it can be manufactured from a metal low resistance material plate, the number of parts can be reduced. For this reason, manufacturing costs can be reduced. Furthermore, since it is formed of a metal low-resistance material,
Heat dissipation can be improved. Further, since the copper plating is applied to the pair of bonding electrode pads 3, 3, the accuracy of the variation in the resistance value can be improved.

Next, a method of manufacturing the current detecting low resistor 1 will be described with reference to FIGS. First,
Hoop material made of manganin plate, copper-nickel plate or nickel-chrome plate (long metal low-resistance material)
Prepare 11 Next, as shown in FIG. 3A, a resist is applied to each of the front and back surfaces of the hoop material 11, and patterning is performed, so that a portion other than the pair of electrode pads 3, 3 and the pair of electrodes 4, 4 is formed. The resist patterns 12 and 13 are formed in the portion of FIG. Next, as shown in FIG. 3B, copper plating and nickel plating are applied to the front and back surfaces of the hoop material 11, respectively, and a pair of electrode pads 3 and 3 composed of a copper plating layer and a nickel plating layer and a pair of electrodes are formed. 4, 4 are continuously formed. Next, as shown in FIG. 3C, the resist patterns 12, 13 are peeled off.

Next, as shown in FIG. 3D, a portion between the pair of electrode pads 3 of each unit in the hoop material 11 is pressed and bent toward the surface side by press working.
The upper part protrudes into a flat chevron. Next, as shown in FIG. 3E, trimming adjustment is performed by making a cut K in the low resistor 1 of each unit with a laser or the like. Next, after coating with a protective coat as necessary, masking for solder is performed, and the electrodes 4 and 4 are plated with solder. Then, FIG.
By cutting at the position of the dashed line in (e), individual chip-shaped low resistors 1 are obtained. Next, after the measurement and inspection, taping is sequentially performed by an automatic taping device.

FIGS. 4 and 5 are a plan view and a side view showing a current measuring low resistor 21 according to another embodiment of the present invention. In these drawings, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be simplified. This current measuring low resistor 21 is different from the current measuring low resistor 1 in that a pair of bonding electrode pads 23 are formed on the entire surface of both ends of the surface of the metal low resistor 2. , Other configurations are the same.

Next, a method of manufacturing the current detecting low resistor 21 will be described with reference to FIGS. In these figures, the same components as those in FIGS. 3A to 3E are denoted by the same reference numerals, and description thereof will be simplified. First, as shown in FIG. 6A, a film mask 31 for plating such as an organic acid-resistant tape is formed on each of the front and back surfaces of the hoop material 11 except for both side ends along the longitudinal direction.
Attach 32. Next, as shown in FIG. 6B, copper plating and nickel plating are applied to the front and back surfaces of the hoop material 11, respectively, and a pair of electrode pads 23, 23 and a pair of electrodes made of a copper plating layer and a nickel plating layer are formed. 4,
4 are continuously formed on both side ends of the hoop material 11 in a belt shape. Next, as shown in FIGS. 6C and 6D, the film masks 31 and 32 are peeled off.

Next, as shown in FIGS. 6E and 6F, the portion between the pair of electrode pads 23 of the hoop material 11 is continuously formed along the longitudinal direction of the hoop material 11 by pressing. It is pressed and bent toward the surface side so as to protrude into a mountain-shaped ridge having a flat upper part. Next, after masking for solder plating, a pair of electrodes 4 and 4 are plated with solder. Next, after cutting as shown by a dashed line in FIG. 6E to obtain individual chip-shaped low resistors 1, FIG.
As shown in (g), a cut K is made in the low resistor 1 with a laser or the like to perform trimming adjustment. Next, after the measurement and inspection, taping is sequentially performed by an automatic taping device.

In the manufacturing methods of the above embodiments,
Although the hoop material 11 is used, a large number of low-resistance devices 1 may be manufactured in a matrix using a square-plate-shaped metal low-resistance material instead.

[0022]

As described above, according to the present invention,
Since it can be manufactured by pressing a plate-shaped metal low-resistance material and forming a pair of electrode pads and a pair of connection electrodes on the front and back surfaces respectively, the manufacturing process can be simplified. it can. And since it can be manufactured from a plate-shaped metal low-resistance material, the number of parts can be reduced, and the manufacturing cost can be reduced. Furthermore, since it is formed of a metal low-resistance material, heat dissipation can be improved. In addition, since the pair of electrode pads are plated with copper, the accuracy of resistance value variation is improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a current detection low resistor according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIGS. 3A and 3B are side views for explaining a method of manufacturing the current detecting low resistor according to the embodiment of the present invention; FIGS.

FIG. 4 is a plan view showing a current detection low resistor according to another embodiment of the present invention.

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a diagram for explaining a method of manufacturing a current detection low resistor according to another embodiment of the present invention.
6 (a) to 6 (c) are plan views, FIG. 6 (d) is a cross-sectional view, FIG. 6 (e) is a plan view, FIG. 6 (f) is a cross-sectional view, and FIG. 6 (g) is a side view. .

FIG. 7 is a side view showing a conventional low resistor for current detection.

[Explanation of symbols]

 1, 21 Low resistance for current detection 2 Metal low resistance 3, 23 Electrode pad 4 Connection electrode 11 Hoop material (Low resistance metal material) 12, 13 Resist pattern 31, 32 Plating film mask

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsumi Takagi 14016 Naka-minowa, Minowa-machi, Kamiina-gun, Nagano Prefecture 72) Inventor Hiroshi Kato 14016 Nakaminowa, Minowa-machi, Kamiina-gun, Nagano Prefecture F-term (reference) 2G025 AB05

Claims (4)

[Claims] 1. A plate-shaped metal low-resistance element has a central portion protruding toward the front surface, a pair of bonding electrode pads formed at both ends of the front surface, and a pair of connection electrodes formed at both ends of the rear surface. A low resistor for detecting current. 2. After forming a resist pattern on each of the front and back surfaces of the plate-shaped metal low-resistance material, electrolytic plating is performed to form a pair of electrode pads on the front surface and a pair of connection electrodes on the back surface. A method for manufacturing a current-detecting low-resistance resistor, characterized in that a portion between the pair of electrode pads in the metal low-resistance material is protruded toward the front side by press working. 3. A plating film mask is formed on each of the front and back surfaces of a plate-shaped metal low-resistance material, and then electroplating is performed to form a pair of electrode pads on the front surface and a pair of connection electrodes on the back surface. Forming a portion between the pair of electrode pads in the metal low-resistance material to be protruded toward the front side by press working. 4. The current detection low resistor according to claim 1, wherein said pair of electrode pads are formed by applying copper plating and further applying nickel plating.