JP2001110601A - Resistor and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resistor of high reliability, in which a thin-film resistor is not oxidized even when the resistor is used in an atmosphere of high temperature and high humidity or of corrosive gas like sulfur component, and moisture, gas, etc., permeate into the inside from a protective film, and a manufacturing method of the resistor. SOLUTION: This resistor is provided with an upper surface electrode 22 formed on the upper surface of a substrate 21, a thin-film resistor 24 formed in such a manner that both end portions overlap with the electrode 22, a metal oxide film 25 formed covering the thin-film resistor 24 and a part of the electrode 22, a protective film 26 which covers from the end surface of the thin-film resistor 24 to a part positioned outside it and the metal oxide film 25, and a side surface electrode 27 which is formed on the side surface of the substrate 21 and connected electrically with the upper surface electrode 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor widely used in circuits of various electric devices and a method of manufacturing the resistor.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller, the mounting area for electronic components has been reduced, and thus the demand for surface-mounted components has increased. Among them, demands for chip-type resistors, which are high-precision parts, are also diverse, and there is an increasing demand for thin-film chip resistors that can ensure reliability even under special environments.

FIG. 7 is a sectional view of a conventional resistor.

In FIG. 7, reference numeral 1 denotes a substrate made of an insulator such as alumina. Reference numeral 2 denotes Ni provided on the upper surface of the substrate 1.
This is a thin film resistor made of a thin film such as a CrAl alloy. Reference numeral 3 denotes an intermediate electrode provided at an end of the upper surface of the thin film resistor 2 and made of an alloy containing Ni as a main component. Reference numeral 4 denotes a protective layer made of a resin provided so as to cover the thin film resistor 2 and a part of the intermediate electrode 3. 5 is a thin film resistor 2 and an intermediate electrode 3
These are side electrodes made of NiCr or the like provided on opposite side surfaces of the substrate 1 so as to be electrically connected to the substrate 1. Reference numeral 6 denotes Ni plating provided on the opposite side surface of the substrate 1 so as to cover at least the side surface electrode 5. Reference numeral 7 denotes solder plating provided on the opposite side surface of the substrate 1 so as to cover the Ni plating 6.

A method of manufacturing the conventional resistor having the above-described structure will be described below.

FIGS. 8A to 8F are process diagrams showing a conventional method for manufacturing a resistor.

First, as shown in FIG. 8A, a thin film resistor 12 is formed by depositing a NiCrAl alloy to a thickness of about 500.degree. I do.

Next, as shown in FIG. 8B, an alloy containing Ni as a main component is deposited to a thickness of about 0.5 μm on the entire upper surface of the thin film resistor 12 by a sputtering method. Thereafter, a part of the alloy is removed by a photolithography method to form intermediate electrodes 13 at both ends of the substrate 11, and a part of the thin film resistor 12 is removed to approximate a predetermined resistance value.
Heat aging is performed at 0 to 350 ° C. for about 3 hours.

Next, as shown in FIG. 8C, the thin film resistor 12 is cut by laser trimming to form a trimming groove 14, and the resistance value is corrected.

Next, as shown in FIG. 8D, a protective film 15 made of resin is formed so as to cover a part of the intermediate electrode 13 and the thin film resistor 12.

Next, as shown in FIG. 8E, Cr is sputtered on the side surface of the substrate 11 to a thickness of about 200 ° so as to be electrically connected to the thin film resistor 12 and the intermediate electrode 13. Then, NiV is deposited to a thickness of about 1 μm to form the side electrode 16.

Finally, as shown in FIG. 8F, a plating layer 17 is formed by depositing about 2 μm of nickel plating and about 6 μm of solder plating so as to cover the intermediate electrode 13 and the side electrodes 16. Manufacturing conventional resistors.

[0013]

In the conventional resistor described above, the protective film 15 and the thin film resistor 12 or the intermediate electrode 13 are used.
Is a dissimilar material of resin and metal, so that the adhesion may be reduced. In particular, when this resistor is used in an atmosphere containing high-temperature, high-humidity or corrosive gas such as sulfur, moisture, gas, and the like enter from a portion where the adhesion of the protective film 15 is reduced, and the thin film resistor 12 To oxidize,
There was a problem that the reliability was reduced.

The present invention solves the above-mentioned conventional problems. When used in an atmosphere containing a corrosive gas such as high temperature and high humidity or sulfur, moisture, gas, and the like enter into the inside from the protective film. Another object of the present invention is to provide a highly reliable resistor that does not oxidize a thin film resistor and a method of manufacturing the same.

[0015]

In order to achieve the above object, a resistor according to the present invention comprises an insulating substrate, at least one pair of upper electrodes provided at both ends of the upper surface of the substrate, and a pair of upper electrodes. At least one thin-film resistor provided so that both ends thereof overlap the upper electrode, a metal oxide film provided so as to cover the thin-film resistor and a part of the upper electrode, and an outer side of an end face of the thin-film resistor And a side surface provided on a side surface of the substrate so as to be electrically connected to the pair of upper surface electrodes, while providing a protection film provided so as to cover a portion positioned at a position above the end surface of the metal oxide film. According to this configuration, when used in an atmosphere containing corrosive gas such as high temperature and high humidity or sulfur content, even if moisture or gas intrudes from the protective film, Oxidize the thin film resistor It is intended that there is no reliable resistors can be obtained.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to an insulating substrate, at least a pair of upper electrodes provided at both ends of an upper surface of the substrate, and a pair of upper electrodes provided at both ends of the pair of upper electrodes. At least one thin-film resistor provided so that portions overlap each other; a metal oxide film provided so as to cover the thin-film resistor and a part of an upper electrode; and a portion located outside an end face of the thin-film resistor. And a side surface electrode provided on a side surface of the substrate so as to be electrically connected to the pair of upper surface electrodes. That
According to this configuration, since the metal oxide film is provided so as to cover a part of the thin-film resistor and the upper surface electrode, when used in an atmosphere containing corrosive gas such as high temperature and high humidity or sulfur content, Even if moisture, gas or the like intrudes through the protective film, the presence of the metal oxide film has the effect of preventing oxidation of the thin film resistor.

According to a second aspect of the present invention, there is provided an insulating substrate, at least a pair of upper electrodes provided on both ends of the upper surface of the substrate, and both ends provided to overlap the pair of upper electrodes. And at least one thin-film resistor, a metal oxide film provided so as to cover the thin-film resistor and a part of the top electrode, and so as to cover the thin-film resistor and to cover an inner side of an end face of the metal oxide film. A protective film provided, an intermediate electrode made of a conductive resin material provided so as to cover the upper surface of the upper electrode and the metal oxide film and to be in contact with the protective film, and electrically connected to the upper electrode and the intermediate electrode; And a side electrode provided on the side surface of the substrate as described above. According to this configuration, the protective film is provided on the metal oxide film so as to be in contact with the intermediate electrode made of a conductive material. Protective film Compared with those provided only on the metal oxide film, adhesion of the protective film is expected to have an effect of improving.

According to a third aspect of the present invention, in the second aspect of the present invention, the protective film covers the portion located outside the end face of the thin film resistor and also covers the inside from the end face of the metal oxide film. According to this configuration,
Since the upper surface of the thin-film resistor is completely covered with the metal oxide film and the protective film, the thin-film resistor has an effect that it is difficult for moisture, gas and the like from the upper surface to enter the inside of the thin-film resistor.

According to a fourth aspect of the present invention, in the second aspect, the protective film is provided so as to cover the inside from the end face of the thin film resistor and to cover the inside from the end face of the metal oxide film. According to this configuration, since the protective film is located inside the end face of the thin-film resistor, the intermediate electrode layer made of a conductive resin material provided so as to be in contact with the protective film can be enlarged. Thereby, the adhesion between the metal oxide film and the thin film resistor is improved.

According to a fifth aspect of the present invention, at least one pair of upper electrodes is formed at both ends of the upper surface of the insulating substrate, and at least one thin film resistor is formed so that both ends overlap the pair of upper electrodes. Forming a metal oxide film so as to cover the thin film resistor and a part of the upper electrode, and to cover a portion located outside an end face of the thin film resistor and to cover an inside from an end face of the metal oxide film. A protective film is formed as described above, and a side electrode is formed on a side surface of the substrate so as to be electrically connected to the pair of upper electrodes. According to this manufacturing method, the thin film resistor and the upper surface are formed. Since a metal oxide film is formed to cover a part of the electrode, when used in an atmosphere containing corrosive gas such as high temperature and high humidity or sulfur, moisture and gas etc. Even if invaded, metal acid The presence of the film, and has an effect that it is possible to prevent oxidation of the thin film resistor.

According to a sixth aspect of the present invention, at least one pair of upper electrodes is formed at both ends of the upper surface of the insulating substrate, and at least one thin film resistor is formed so that both ends overlap the pair of upper electrodes. Forming a metal oxide film so as to cover the thin film resistor and a part of the upper electrode; forming a protective film so as to cover an inner side of an end face of the metal oxide film; Forming an intermediate electrode made of a conductive resin material so as to cover the upper surface and contact the protective film,
A side electrode is formed on the side surface of the substrate so as to be electrically connected to the upper electrode and the intermediate electrode. According to this manufacturing method, the side electrode is formed so as to be in contact with the intermediate electrode made of a conductive resin material. Since the protective film is formed on the metal oxide film, it has an effect of improving the adhesion of the protective film as compared with the case where the protective film is formed only on the metal oxide film.

(Embodiment 1) Hereinafter, a resistor according to Embodiment 1 of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a resistor according to the first embodiment of the present invention.

In FIG. 1, reference numeral 21 denotes an insulating substrate containing 96% alumina. Reference numeral 22 denotes an upper surface electrode made of a metal such as Au and provided at least as a pair at both ends of the upper surface of the substrate 21. Reference numeral 23 denotes a lower surface electrode made of an Au-based metal or the like provided at least as a pair on both ends of the lower surface of the substrate 21 as necessary. 24 is a pair of upper electrodes 22
Provided at least one so that both ends overlap
It is a thin film resistor made of a metal such as Cr. Reference numeral 25 denotes a metal oxide film made of aluminum oxide, silicon oxide, titanium oxide, or the like provided so as to cover the thin film resistor 24 and a part of the upper electrode 22. Reference numeral 26 denotes a metal oxide film 25 which covers a portion located outside the end face of the thin film resistor 24 and
Is a protective film made of an epoxy-based resin provided so as to cover the inside from the end face. Reference numeral 27 denotes a side electrode provided on a side surface of the substrate 21 so as to be electrically connected to the pair of upper electrodes 22. Reference numeral 28 denotes nickel plating provided so as to cover the exposed metal oxide film 25, upper surface electrode 22, and side electrode 27. Reference numeral 29 denotes solder plating provided so as to cover the nickel plating 28.

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

FIGS. 2A to 2G are process diagrams showing a method of manufacturing the resistor according to the first embodiment of the present invention.

First, as shown in FIG. 2A, paste made of a metal organic material containing Au as a main component is screen-printed on both ends of the upper surface of an insulating substrate 31 containing 96% alumina. dry. Further, using a belt-type continuous firing furnace, at about 850 ° C., a peak time of about 6 minutes, and an IN-
By baking with an OUT time of about 45 minutes, at least one pair of upper electrodes 32 is formed. In addition,
If necessary, lower surface electrodes (not shown) may be formed on both ends of the lower surface of the substrate 31 by the same method as the upper surface electrode 32.

Next, as shown in FIG. 2B, a NiCr-based metal material is deposited by a sputtering method so that both ends overlap the pair of upper electrodes 32, and at least one thin-film resistor 33 is formed. I do. Further, a first groove 34 is formed in the thin film resistor 33 by a photolithography method so as to approach a predetermined resistance value, and the resistance value is adjusted.

Next, as shown in FIG. 2C, aluminum oxide, silicon oxide, titanium oxide or the like is sputtered to a thickness of about 100 to 5 so as to cover at least the thin film resistor 33.
A metal oxide film 35 covering a part of the thin film resistor 33 and the upper electrode 32 is formed as a predetermined pattern by a photolithography method. Further, in order to stabilize the thin film resistor 33, thermal aging is performed at about 250 to 350 ° C. for about 5 hours.

Next, as shown in FIG. 2D, a second groove 36 is formed by laser trimming to adjust the resistance value of the thin film resistor 33 to a predetermined resistance value, and the resistance value is adjusted.

Next, as shown in FIG. 2E, an epoxy resin paste is screen-coated so as to cover the portion located outside the end face of the thin film resistor 33 and to cover the inside from the end face of the metal oxide film 35. Printing is performed and dried in a dryer at about 200 ° C. for about 30 minutes to form a protective film 37.

Next, as shown in FIG. 2F, a NiCr-based metal material is deposited on the side surface of the substrate 31 by a sputtering method so as to be electrically connected to the pair of upper surface electrodes 32, and the side electrode is formed. 38 are formed.

Finally, as shown in FIG. 2G, a plating layer 39 made of nickel plating and solder plating is formed so as to cover the exposed metal oxide film 35, upper electrode 32 and side electrode 38. To manufacture resistors.

(Embodiment 2) Hereinafter, a resistor according to Embodiment 2 of the present invention will be described with reference to the drawings.

FIG. 3 is a sectional view of a resistor according to the second embodiment of the present invention.

In FIG. 3, reference numeral 41 denotes an insulating substrate containing 96% alumina. Reference numeral 42 denotes an upper surface electrode made of a metal such as Au and provided at least in pairs at both ends of the upper surface of the substrate 41. Reference numeral 43 denotes a lower surface electrode made of a metal such as Au and provided at least as a pair at both ends of the lower surface of the substrate 41 as necessary. 44 is a pair of upper electrodes 42
Provided at least one so that both ends overlap
It is a thin film resistor made of a metal such as Cr. Reference numeral 45 denotes a metal oxide film made of aluminum oxide, silicon oxide, titanium oxide, or the like provided so as to cover the thin film resistor 44 and a part of the upper electrode 42. Reference numeral 46 denotes a metal oxide film 45 that covers a portion located outside the end face of the thin film resistor 44 and a metal oxide film 45.
Is a protective film made of an epoxy-based resin provided so as to cover the inside from the end face. Reference numeral 47 denotes an intermediate electrode made of a conductive resin material provided so as to cover a part of the upper surfaces of the upper electrode 42 and the metal oxide film 45 and to be in contact with the protective film 46. Reference numeral 48 denotes a side surface electrode provided on the side surface of the substrate 41 so as to be electrically connected to the upper surface electrode 42 and the intermediate electrode 47. Reference numeral 49 denotes nickel plating provided so as to cover the exposed metal oxide film 45, the upper electrode 42, and the side electrodes 48. 50 is a solder plating provided so as to cover the nickel plating 49.

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

FIGS. 4A to 4H are process diagrams showing a method of manufacturing a resistor according to the second embodiment of the present invention.

First, as shown in FIG. 4A, paste made of a metal organic material containing Au as a main component is screen-printed on both ends of the upper surface of an insulating substrate 51 containing 96% alumina. dry. Further, using a belt-type continuous firing furnace, at about 850 ° C., a peak time of about 6 minutes, and an IN-
By baking with an OUT time profile of about 45 minutes, at least one pair of upper electrodes 52 is formed. In addition,
If necessary, lower surface electrodes (not shown) may be formed on both ends of the lower surface of the substrate 51 by the same method as the upper electrode 52.

Next, as shown in FIG. 4B, a NiCr-based metal material is deposited by a sputtering method so that both ends overlap the pair of upper electrodes 52, and at least one thin film resistor 53 is formed. I do. Further, a first groove 54 is formed in the thin film resistor 53 by a photolithography method so as to approach a predetermined resistance value, and the resistance value is adjusted.

Next, as shown in FIG. 4C, aluminum oxide, silicon oxide, titanium oxide or the like is sputtered to a thickness of about 100 to 1 so as to cover at least the thin film resistor 53.
Then, a thin film resistor 53 and a metal oxide film 55 covering a part of the upper electrode 52 are formed as a predetermined pattern by a photolithography method. Furthermore, a thin film resistor 5
In order to stabilize 3, heat aging is performed at about 250 to 350 ° C. for about 5 hours.

Next, as shown in FIG. 4D, a second groove 56 is formed by laser trimming to adjust the resistance of the thin film resistor 53 to a predetermined resistance, and the resistance is adjusted.

Next, as shown in FIG. 4E, an epoxy resin paste is screen-coated so as to cover the portion located outside the end face of the thin film resistor 53 and to cover the inside from the end face of the metal oxide film 55. Printing is performed and dried in a dryer at about 200 ° C. for about 30 minutes to form a protective film 57.

Next, as shown in FIG. 4F, the upper surface of the upper electrode 52 and the metal oxide film 55 are covered and the protective film 57 is formed.
An intermediate electrode 58 made of a conductive resin material is formed so as to be in contact with. At this time, if a material similar to the protective film 57, for example, a resin material such as an epoxy-based or phenol-based resin is used as the conductive resin material for forming the intermediate electrode 58, the adhesion between the intermediate electrode 58 and the protective film 57 is improved. And this
The effect of preventing moisture, gas, and the like from entering the inside of the thin film resistor 53 is further enhanced. Further, even if the thickness of the metal oxide film 55 exceeds 500 °, the adhesion is maintained.

Next, as shown in FIG. 4G, a NiCr-based metal material is deposited on the side surface of the substrate 51 by a sputtering method so as to be electrically connected to the upper electrode 52 and the intermediate electrode 58. A side electrode 59 is formed.

Finally, as shown in FIG. 4 (h), a plating layer 60 made of nickel plating and solder plating is formed so as to cover the exposed metal oxide film 55, the upper electrode 52 and the side electrode 59. To manufacture resistors.

In the second embodiment of the present invention, the intermediate electrode 58 is formed after the protection film 57 is provided. However, the present invention is not limited to this. For example, the metal oxide film 55 may be formed. Then, after thermal aging, the intermediate electrode 58 may be formed.

In FIG. 3, the case where the protective film 46 is provided so as to cover the portion located outside the end face of the thin film resistor 44 has been described. However, as shown in FIG. It may be provided so as to cover the inside of the end face of the thin film resistor 62 and the inside of the end face of the metal oxide film 63. In this case, since the protective film 61 is located inside the end face of the thin film resistor 62, the intermediate electrode 64 made of a conductive resin material provided to be in contact with the protective film 61 can be further enlarged. Thereby, the adhesion between the metal oxide film 63 and the thin film resistor 62 is improved.

Further, in the above-described embodiment of the present invention, the description has been given of the case where the present invention is applied to a resistor composed of one thin-film resistor and a pair of upper electrodes.
A thin film resistor (not shown) is provided on the upper surface of the substrate 71 as shown in FIG.
The same effects as those of the embodiment of the present invention can be obtained even when the present invention is employed in a multiple-type resistor having a plurality of pairs of upper electrodes 72.

[0050]

As described above, the resistor according to the present invention has an insulating substrate, at least a pair of upper electrodes provided at both ends of the upper surface of the substrate, and both ends overlapping the pair of upper electrodes. At least one thin-film resistor provided as described above, a metal oxide film provided so as to cover the thin-film resistor and a part of the upper electrode, and a portion located outside the end face of the thin-film resistor. A protective film provided so as to cover an inner side of an end face of the metal oxide film, and a side electrode provided on a side surface of the substrate so as to be electrically connected to the pair of upper electrodes. According to this configuration, since the metal oxide film is provided so as to cover the thin-film resistor and a part of the upper electrode, when used in an atmosphere containing corrosive gas such as high temperature and high humidity or sulfur content, Moisture, gas, etc. from the protective film Even invaded part, by the presence of a metal oxide film, it is possible to prevent oxidation of the thin film resistor, thereby, those having an excellent effect that it is possible to obtain a highly reliable resistors.

[Brief description of the drawings]

FIG. 1 is a sectional view of a resistor according to a first embodiment of the present invention.

FIGS. 2A to 2G are process diagrams showing a method for manufacturing the resistor.

FIG. 3 is a sectional view of a resistor according to a second embodiment of the present invention.

FIGS. 4A to 4H are process diagrams showing a method for manufacturing the resistor.

FIG. 5 is a sectional view of a resistor showing another example according to the second embodiment of the present invention;

FIG. 6 is a top view of a multiple resistor according to the embodiment of the present invention.

FIG. 7 is a sectional view of a conventional resistor.

FIGS. 8A to 8F are process diagrams showing a method for manufacturing the resistor.

[Explanation of symbols]

 21, 31, 41, 51, 71 Substrate 22, 32, 42, 52, 72 Upper electrode 24, 33, 44, 53, 62 Thin film resistor 25, 35, 45, 55, 63 Metal oxide film 26, 37, 46 , 57, 61 Protective film 27, 38, 48, 59 Side electrode 47, 58 Intermediate electrode

Continued on the front page F term (reference) 5E032 BA12 BB01 CA02 CC14 CC16 TA13 TB02 5E033 AA02 BB02 BC01 BD01 BE02 BF05 BG02 BG03 BH02

Claims (6)

[Claims] 1. An insulating substrate, at least one pair of upper electrodes provided at both ends of an upper surface of the substrate, and at least one thin-film resistor provided so that both ends overlap the pair of upper electrodes. And a metal oxide film provided so as to cover the thin film resistor and a part of the upper electrode, and a portion located outside an end face of the thin film resistor and also covers an inside from an end face of the metal oxide film. A protective film provided as described above, and side electrodes provided on side surfaces of the substrate so as to be electrically connected to the pair of upper electrodes. 2. An insulating substrate, at least one pair of upper electrodes provided at both ends of an upper surface of the substrate, and at least one thin-film resistor provided so that both ends overlap the pair of upper electrodes. A metal oxide film provided so as to cover a part of the thin film resistor and the upper electrode, and a protective film provided so as to cover the thin film resistor and to cover an inner side of an end face of the metal oxide film, An intermediate electrode made of a conductive resin material provided to cover the upper surface of the upper electrode and the metal oxide film and to be in contact with the protective film; and a side surface of the substrate so as to be electrically connected to the upper electrode and the intermediate electrode. And a side electrode provided in the resistor. 3. The resistor according to claim 2, wherein the protective film is provided so as to cover a portion located outside the end face of the thin film resistor and to cover the inside from the end face of the metal oxide film. 4. The resistor according to claim 2, wherein the protective film is provided so as to cover the inside from the end face of the thin film resistor and to cover the inside from the end face of the metal oxide film. 5. At least one pair of upper electrodes is formed at both ends of an upper surface of an insulating substrate, and at least one thin film resistor is formed so that both ends overlap the pair of upper electrodes. A metal oxide film is formed so as to cover a part of the upper electrode, and a protective film is formed so as to cover a portion located outside an end face of the thin film resistor and to cover an inside from an end face of the metal oxide film. A method of manufacturing a resistor, wherein side electrodes are formed on side surfaces of the substrate so as to be electrically connected to the pair of upper electrodes. 6. At least one pair of upper electrodes is formed at both ends of an upper surface of an insulating substrate, and at least one thin film resistor is formed so that both ends overlap with the pair of upper electrodes. A metal oxide film is formed so as to cover a part of the upper electrode, and a protective film is formed so as to cover an inner side of an end face of the metal oxide film. A method of manufacturing a resistor, comprising: forming an intermediate electrode made of a conductive resin material so as to be in contact therewith; and forming a side electrode on a side surface of the substrate so as to be electrically connected to the upper electrode and the intermediate electrode.