JPH09320802A - Resistor - Google Patents

Abstract

(57) Abstract: In a resistor used for current detection, an object is to provide a small resistor. SOLUTION: A substrate 11 and a resistance foil 12 provided from an upper surface to a side surface of the substrate 11 via an inorganic adhesive 13 containing silica as a main component, and silica provided on the upper surface of the substrate 11 via the resistance foil 12. Is electrically connected to the resistance foil 12 and the lower surface electrode 15 on the side surface of the substrate 11. And a plating layer 17 provided so as to cover the lower surface electrode 15 and the side surface electrode 16, and an inorganic adhesive and an inorganic coating material containing silica as a main component. Therefore, it is possible to provide a small-sized nonflammable resistor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low resistance resistor used for current detection in a control circuit for a motor or a switching regulator.

[0002]

2. Description of the Related Art In recent years, as resistors used for current detection in control circuits and the like, chip-type resistors that can be surface-mounted have been demanded as electronic devices to be mounted have become smaller.

A conventional resistor will be described below with reference to the drawings. For a conventional resistor, see Japanese Patent Laid-Open No.
No. 267707, a structure in which a low resistance metal resistor having a pair of current terminals and a pair of voltage terminals is sandwiched between two insulating members, and the terminal portions of the metal resistors corresponding to the current terminals and the voltage terminals are bent. Are disclosed.

FIG. 5 (a) is a top view of a metal resistor, which is an essential part of a conventional resistor, seen through, and FIG. 5 (b) is a side view of the same.

In the figure, 1 is a first made of alumina or the like.
It is a ceramic substrate. 2 is the first ceramic substrate 1
Is a metal resistor made of any one kind of metal plate such as a copper-nickel plate, a manganin plate, a zelanine plate, and an iron-copper plate provided on the upper surface of the. Reference numeral 3 denotes a pair of current terminals provided by bending the metal resistor 2 into a U-shape on the opposing end faces of the first ceramic substrate 1. 4 is the first ceramic substrate 1
Is a pair of voltage terminals provided by bending the metal resistor 2 in a U shape at one end surface of the. Reference numeral 5 is an opening provided in the metal resistor 2 by trimming in order to adjust the resistance value. A second ceramic substrate 6 made of alumina or the like is provided on the upper surface of the first ceramic substrate 1 so as to sandwich the metal resistor 2.

A method of manufacturing the conventional resistor having the above structure will be described below. First, the metal resistor 2
In the step of forming, a series of resistors in which a plurality of metal resistors 2 are continuously formed by press punching a metal plate of any one of copper-nickel plate, manganin plate, zeranin plate, iron-copper plate, etc. with a die. Form a group. Further, the portion of the metal resistor 2 forming the current terminal 3 and the voltage terminal 4 is plated with solder.

Next, as a trimming step, a current is made to flow between the current terminals 3 at both ends of the series of resistor groups obtained in the previous step, and the voltage between the voltage terminals 4 of the metal resistors 2 is measured. The opening 5 is formed on the metal resistor 2 by trimming and adjusting with laser trimming, sand blasting, a diamond cutter, a grinder cutter, or the like.

Next, as a step of forming the metal resistor 2 on the upper surface of the ceramic substrate 1, the series of resistor groups obtained in the previous step is cut into each resistor to obtain the metal resistor 2. The first ceramic substrate 1 made of alumina or the like is attached to the upper surface of the first ceramic substrate 1 with an adhesive, and then the second ceramic substrate 6 is attached so as to sandwich the metal resistor 2. After this, the first
Of the metal resistor 2 on the opposite end faces of the ceramic substrate 1 of
The pair of current terminals 3 are formed by bending the metal resistor 2 in a U shape at one end surface of the first ceramic substrate 1 to form a pair of voltage terminals 4.

Finally, the first ceramic substrate 1 and the second ceramic substrate 2 which sandwich the metal resistor 2 are molded and sealed with an insulating material such as resin dip to manufacture a conventional resistor. Was there.

[0010]

However, in the above-mentioned conventional resistor, the metal resistor 2 is used as the first and second metal resistors.
Since the structure is sandwiched between the ceramic substrates 1 and 6, the resistor is increased by the thickness of the second ceramic substrate 6, and a smaller size is required.

The present invention aims to provide a small-sized resistor.

[0012]

In order to achieve the above object, the present invention provides a resistance foil provided via an inorganic adhesive containing silica as a main component, and a resistance foil provided on the upper surface of a substrate via the resistance foil. And a protective film made of an inorganic coating material containing silica as a main component.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises a substrate, and a resistance foil provided from the upper surface to the side surface of the substrate via an inorganic adhesive containing silica as a main component.
A protective film made of an inorganic coating material containing silica as a main component, which is provided on the upper surface of the substrate via the resistance foil, a pair of lower surface electrodes provided on a side portion of the lower surface of the substrate, and a side surface of the substrate. It is provided with a pair of side surface electrodes provided so as to electrically connect the resistance foil and the lower surface electrode, and a plating layer provided so as to cover the lower surface electrode and the side surface electrode.

Further, the invention according to claim 2 is provided through a substrate having at least one pair of concave portions on opposite side surfaces and an inorganic adhesive containing silica as a main component from the upper surface to the side surface of the concave portion of the substrate. Resistance foil, a protective film made of an inorganic coating material containing silica as a main component provided on the upper surface of the substrate via the resistance foil, and a pair of lower surface electrodes provided on the side surface of the lower surface of the substrate. A pair of side surface electrodes provided so as to be electrically connected to the resistance foil and the lower surface electrode in the concave portion of the substrate, and a plating layer provided so as to cover the lower surface electrode and the side surface electrode Is.

As described above, since the inorganic adhesive containing silica as the main component and the inorganic coating are used, the thermal conductivity is good, and even if the heat generated when the current is applied is transmitted from the substrate, the heat is efficiently radiated. It is a thing.

(Embodiment 1) A resistor according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a perspective view in which a resistor is partly cut away in the embodiment of the present invention, and FIG. 1B is a sectional view taken along the line AA.

In the figure, 11 is a substrate made of ceramic or the like. Reference numeral 12 is a resistance foil made of a metal such as manganin foil, constantan foil, zeranin foil, or nichrome foil, which is provided from the upper surface to the side surface of the substrate through an inorganic adhesive 13 containing silica as a main component. Reference numeral 14 is a protective film provided on the upper surface of the substrate 11 via the resistance foil 12 and made of an inorganic coating material containing silica as a main component. Reference numeral 15 denotes a pair of lower surface electrodes provided on the side surface of the lower surface of the substrate 11 and made of a metal containing at least one of silver, silver palladium, copper and the like. 16 is a resistance foil 1 on the side surface of the substrate 11.
2 is a pair of side surface electrodes made of a metal containing at least one of silver, silver palladium, copper, etc., provided so as to electrically connect 2 to the lower surface electrode 15. Reference numeral 17 denotes a plating layer such as solder provided so as to cover the resistance foil 12, the side surface electrode 16 and the lower surface electrode 15 exposed from the protective film 14.

Regarding the resistor configured as described above,
Hereinafter, the manufacturing method will be described with reference to the drawings.

FIG. 2 is a process drawing showing a method of manufacturing a resistor according to an embodiment of the present invention. First, as shown in FIG. 2A, a dividing groove 22 for dividing the substrate 21 made of ceramic or the like into individual pieces is formed vertically and horizontally.

Next, as shown in FIG. 2B, the substrate 21
A metal paste such as silver, silver-palladium, or copper is printed on the surface that will be the lower surface of and the lower surface electrode 2 is baked at about 850 to 900 ° C.
3 is formed.

Next, as shown in FIG. 2C, the substrate 21
Is divided in one direction along the division groove 22, and the strip-shaped substrate 24
Get.

Next, as shown in FIG. 2D, a metal paste of silver, silver palladium, copper or the like is printed on the side surface of the strip-shaped substrate 24 so as to be electrically connected to the lower surface electrode 23, and about 8
The side electrode 25 is formed by firing at 50 to 900 ° C.

Next, as shown in FIG. 2E, an inorganic adhesive 26 containing silica as a main component is applied to the upper surface of the strip substrate 24. As the inorganic adhesive 26, methanol, IP
A low boiling point solvent such as A, acetone or butyl acetate is preferable.

Next, as shown in FIG. 2 (f), from the upper surface to the side surface of the strip-shaped substrate 24 via the inorganic adhesive 26 applied in the previous step, the manganin foil, the constantan foil, the zeranin foil, and the nichrome foil are provided. A resistance foil 27 made of any of the above metals is attached and thermocompression-bonded to fix.

Next, as shown in FIG. 2 (g), the resistance foil 2
A cut 28 is made in 7 by a laser and a grinder so as to have a predetermined resistance value, and trimming is performed.

Next, as shown in FIG. 2 (h), an inorganic coating material containing silica as a main component is screen-printed, dispenser or the like on the upper surface of the strip-shaped substrate 24 so as to cover at least the trimming 28 via the resistance foil 27. The coating is applied and baked at about 250 ° C. to form the protective film 29. At this time, as the inorganic coating material, one in which an inorganic filler is dispersed in a reaction solution obtained by reacting an alkoxysilane or an alkylalkoxysilane with silica sol is used. The alkoxysilane is preferably a lower alkoxy compound, the alkylalkoxysilane is preferably methylmethoxysilane, ethylmethoxysilane, methylethoxysilane, ethylethoxysilane or the like, and the silica sol is produced by condensing these silane compounds in an organic solvent or water. Those obtained are preferred.
As the inorganic filler, metal oxides such as silica, alumina, zirconia and mica are preferable.

Next, as shown in FIG. 2 (i), the protective film 2
9 is subjected to solder plating or the like so as to cover the resistance foil 27, the side surface electrode 25, and the lower surface electrode 23 exposed from 9.
Form 0.

Finally, as shown in FIG. 2 (j), the strip substrate 24 is divided into individual pieces to manufacture the resistor according to the embodiment of the present invention.

(Second Embodiment) A resistor according to another embodiment of the present invention will be described below with reference to the drawings.

FIG. 3A is a perspective view of a resistor according to another embodiment of the present invention with a part cut away, and FIG. 3B is a sectional view taken along line BB.

In the figure, reference numeral 31 is a substrate made of ceramic or the like, and at least one pair of recesses 32 are provided on opposite side surfaces.
It has. Reference numeral 33 is a resistance foil made of any metal such as manganin foil, constantan foil, zeranin foil, or nichrome foil, which is provided from the upper surface to the side surface of the concave portion 32 of the substrate through an inorganic adhesive 34 containing silica as a main component. is there. Reference numeral 35 is a protective film provided on the upper surface of the substrate 31 via the resistance foil 33 and made of an inorganic coating material containing silica as a main component. Reference numeral 36 denotes a pair of lower surface electrodes provided on the side surface of the lower surface of the substrate 31 and made of a metal containing at least one of silver, silver palladium, copper and the like. Reference numeral 37 denotes a pair of metal, which is provided in the concave portion 32 on the side surface of the substrate 31 so as to electrically connect the resistance foil 33 and the lower surface electrode 36 and which contains at least one of silver, silver palladium, copper and the like. It is a side electrode. Reference numeral 38 denotes a plating layer such as solder provided so as to cover the resistance foil 33 exposed from the protective film 35, the side surface electrode 37, and the lower surface electrode 36.

The method of manufacturing the resistor configured as described above is similar to that of the first embodiment, but since the substrate 31 has the recess 32, the side surface electrode 37 is formed at the same time when the lower surface electrode 36 is formed. be able to.

In the second embodiment, the pair of recesses 32 is described as an example, but the same effect can be obtained even when two or more pairs of recesses 39 are formed as shown in FIG. .

[0035]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, since an inorganic adhesive containing silica as a main component and an inorganic paint are used, the thermal conductivity is good, the heat dissipation is small, and the current detection is for improving the nonflammability. A resistor can be provided.

[Brief description of drawings]

FIG. 1A is a perspective view in which a part of a resistor is cut away according to an embodiment of the present invention. FIG. 1B is a sectional view taken along line AA of FIG.

[Fig. 2]

FIG. 3A is a perspective view of a resistor according to another embodiment of the present invention with a part thereof cut away. FIG. 3B is a sectional view taken along line BB of FIG.

FIG. 4 is a perspective view of a resistor according to another embodiment of the present invention.

FIG. 5A is a top view seen through a metal resistor, which is a main part of a conventional resistor, and FIG. 5B is a side view of the same.

[Explanation of symbols]

 11 substrate 12 resistive foil 13 inorganic adhesive 14 protective film 15 lower surface electrode 16 side surface electrode 17 plating layer

Claims (2)

[Claims] 1. A substrate, a resistance foil provided from an upper surface to a side surface of the substrate via an inorganic adhesive containing silica as a main component, and a silica provided on the upper surface of the substrate via the resistance foil. A protective film composed of an inorganic paint as a main component,
A pair of lower surface electrodes provided on the sides of the lower surface of the substrate,
A resistor including a pair of side surface electrodes provided on the side surface of the substrate so as to electrically connect the resistance foil and the lower surface electrode, and a plating layer provided so as to cover the lower surface electrode and the side surface electrode. vessel. 2. A substrate having at least one pair of concave portions on opposite side surfaces, a resistance foil provided from the upper surface to the side surface of the concave portion of the substrate via an inorganic adhesive containing silica as a main component, and a substrate of the substrate. A protective film made of an inorganic paint containing silica as a main component and provided on the upper surface via the resistance foil, a pair of lower surface electrodes provided on the side surfaces of the lower surface of the substrate, and the resistance foil in the concave portion of the substrate. And a pair of side surface electrodes provided so as to be electrically connected to the lower surface electrode, and a plating layer provided so as to cover the lower surface electrode and the side surface electrode.