JPH09312201A - Resistor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a resistor used for various electric devices,
The purpose is to improve the adhesion of the protective layer. A trimming groove is formed by trimming from the upper surface of a glass layer having a resistance layer, and the trimming groove is covered with a protective layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor used in a high density wiring circuit.

[0002]

2. Description of the Related Art A conventional resistor will be described below with reference to the drawings.

FIG. 3 is a cross-sectional view of a conventional resistor, and FIG. 4 is a top view with the protective layer, which is the main part, removed.

In the figure, 1 is a substrate made of insulating alumina. Reference numerals 2 and 3 denote a pair of top surface electrode layers or back surface electrode layers provided on the upper surface or the back surface of the substrate 1 by a thick film. Reference numeral 4 denotes a ruthenium-based resistance layer provided on the upper surface of the substrate 1 so as to be electrically connected to the upper surface electrode layer 2. Reference numeral 5 is a first glass layer provided so as to cover at least the resistance layer 4. Reference numeral 6 denotes a trimming groove obtained by cutting the resistance layer 4 with a laser or the like from the end portion of the substrate 1 toward the center of the upper surface of the first glass layer 5 so as to correct the resistance value to a desired value. Reference numeral 7 is a protective layer provided so as to cover at least the first glass layer 5. Reference numeral 8 denotes a side surface electrode layer provided on the side surface of the substrate 1 so as to electrically connect the top surface electrode layer 2 and the back surface electrode layer 3. Reference numeral 9 denotes a Ni plating layer provided so as to cover at least the side surface electrode layer 8 in order to prevent the side surface electrode layer 8 from being eroded during soldering. Reference numeral 10 is a solder plating layer provided so as to cover at least the Ni plating layer 9 in order to secure solderability.

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

First, a collective substrate (not shown) made of insulating alumina is received. Next, a thick film silver paste is screen-printed and dried on the side surface of the upper surface of the aggregate substrate, and further,
A thick film silver paste is screen-printed and dried on the side surface of the back surface of the aggregate substrate, and baked at a temperature of about 850 ° C. in a belt-type continuous baking furnace to simultaneously form the top electrode layer 2 and the back electrode layer 3.

Next, a ruthenium-based thick film resistor paste is screen-printed and dried on the upper surface of the substrate 1 so as to overlap a part of the upper electrode layer 2, and baked at a temperature of about 850 ° C. in a belt type continuous baking furnace. Then, the resistance layer 4 is formed.

Next, a lead borosilicate glass paste is screen-printed and dried so as to cover at least the resistance layer 4, and is baked at a temperature of about 600 ° C. in a belt type continuous baking furnace to form a first glass layer 5. To do.

Next, in order to make the resistance layer 4 have a desired resistance value, the resistance layer 4 and the first glass layer 5 are irradiated with laser light from the end portion of the substrate 1 toward the center of the first glass layer 5.
Remove a part of the and correct the resistance value. The trimming mark at this time is the trimming groove 6.

Next, to cover at least the resistance layer 4,
The lead borosilicate glass paste is screen-printed, dried, and fired at a temperature of about 600 ° C. in a belt-type continuous firing furnace to form the protective layer 7.

Next, as a preparatory step for forming the side surface electrode layer 8, the collective substrate is divided into strip-shaped strip-shaped substrates (not shown) in order to expose the substrate side surface.

Next, the upper surface electrode layer 2 is formed on the side surface of the strip substrate.
And a thick film silver paste is applied by a roller or dip method so as to overlap a part of the back electrode layer 3, and baked at a temperature of about 600 ° C. in a belt type continuous baking furnace.
The side electrode layer 8 is formed.

Next, as a preparatory step for electrode plating, the strip-shaped substrate on which the side surface electrode layer 8 has been formed is divided into pieces, and the piece-shaped substrate 1 is obtained to form a resistor body.

Finally, in order to cover the exposed side surface electrode layer 8 that electrically connects the exposed top surface electrode layer 2 and back surface electrode layer 3, electrode erosion during soldering is prevented and soldering reliability is improved. To secure the Ni by electrolytic barrel plating.
The resistor was manufactured by forming the plating layer 9 and the solder (Sn-Pb) plating layer 10.

[0015]

However, in the conventional resistor, since the trimming is cut from the end portion of the first glass layer 5 toward the center, the protective layer 7 covers the first glass layer 5 so as to cover the first glass layer 5. However, even if the protective layer 7 is provided, the adhesion between the substrate 1 and the first glass layer 5 and the protective layer 7 becomes weak due to the influence of trimming scatter and the like, which causes a problem that a minute gap is generated.

An object of the present invention is to provide a resistor having improved protective layer adhesion.

[0017]

In order to achieve the above object, the present invention provides a protective layer so as to cover the trimming groove.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention electrically connects a substrate, a pair of upper surface electrode layers provided on a side portion of the upper surface of the substrate, and the upper surface electrode layer. A resistance layer provided as described above, a glass layer provided on the upper surface of the resistance layer, a trimming groove formed by printing the glass layer and the resistance layer from the upper surface of the glass layer, and at least covering the glass layer. In addition, the protective layer is provided so as to cover the trimming groove, and the side surface electrode is provided on the side surface of the substrate so as to be electrically connected to the upper surface electrode layer.

The invention described in claim 2 is the first invention.
The glass layer described in 1) is provided so as to cover the entire upper surface of the resistance layer and cover a part of the substrate.

Further, the invention according to claim 3 provides the invention according to claim 1.
Alternatively, the trimming groove described in 2 is provided from the end of the glass layer having the resistance layer directly thereunder toward the center or toward the center of the glass layer having the resistance layer directly below from the glass layer that covers part of the substrate. It was provided by.

Hereinafter, a resistor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of a resistor according to an embodiment of the present invention, and FIG. 2 is a cutaway top view in which a protective layer, which is a main part of the resistor, is removed.

In the figure, reference numeral 21 is a substrate of insulating alumina or the like. Reference numeral 22 denotes a pair of upper surface electrode layers made of a silver-based thick film or the like provided on the side surface of the upper surface of the substrate 21. Reference numeral 23 denotes a pair of back surface electrode layers provided on the back surface of the substrate 21 as necessary, similarly to the top surface electrode layer 22. 24 is the upper electrode layer 22
It is a resistance layer made of a ruthenium-based thick film or the like provided on the upper surface of the substrate 21 so as to be electrically connected to. Reference numeral 25 denotes a glass layer made of lead borosilicate glass or the like provided so as to cover at least the upper surface of the resistance layer 24 in order to improve the cutting property of trimming performed in a later step, and preferably covers the entire upper surface of the resistance layer 24. At the same time, it is provided on a part of the upper surface of the substrate 21. Reference numeral 26 is a resistance layer 24 formed by laser or the like from the end of the upper surface of the glass layer 25 having the resistance layer 24 directly below to the desired resistance value toward the center.
And a trimming groove obtained by cutting and trimming the glass layer 25. The trimming groove 26 is provided directly below the resistance layer 24.
It may be provided toward the center of the glass layer 25 having the resistance layer 24 directly below the glass layer 25 having no resistance.
A protective layer 27 is provided so as to cover the glass layer 25 and the trimming groove 26. Reference numeral 28 denotes a pair of side surface electrode layers provided on the side surfaces of the substrate 21 so as to electrically connect the top surface electrode layer 22 and the back surface electrode layer 23. 29
Is a Ni plating layer provided so as to cover at least the side electrode layer 28 in order to prevent the side electrode layer 28 from being eroded during soldering. Reference numeral 30 is a solder plating layer provided so as to cover at least the Ni plating layer 29 in order to secure solderability.

A method of manufacturing the resistor having the above-mentioned structure according to the embodiment of the present invention will be described below.

First, a collective substrate (not shown) made of insulating alumina or the like is received. In order to divide the aggregate substrate into strips and individual pieces, a dividing groove is formed by die molding or the like.

Next, the individual substrates 21 are formed on the upper surface of the collective substrate.
The thick-film silver paste is screen-printed and dried at a position which becomes the side part of the upper surface of the substrate. At temperature, peak time 6 minutes, IN-
Firing is performed according to the profile of OUT time of 45 minutes to form a pair of the upper surface electrode layer 22 and the back surface electrode layer 23 at the same time.

Next, a thick film resistance paste containing ruthenium oxide as a main component is screen-printed and dried so as to overlap with a part of the upper surface electrode layer 22 so as to be electrically connected to the upper surface electrode layer 22, and a belt type is used. The resistance layer 24 is formed by firing in a continuous firing furnace at a temperature of 850 ° C. according to a profile with a peak time of 6 minutes and an IN-OUT time of 45 minutes.

Next, a lead borosilicate glass paste is screen-printed and dried on the upper surface of the resistance layer 24 or so as to cover at least the resistance layer 24, and the peak time 6 is applied at a temperature of 600 ° C. in a belt type continuous firing furnace. Minute, IN-OU
The glass layer 25 is formed by firing with a firing profile of T time of 50 minutes.

Next, in order to correct the resistance value, the glass layer 25 having the resistance layer 24 on the lower surface thereof is not provided with the resistance layer 24 from the end of the upper surface toward the center or on the lower surface.
The resistance value is corrected by trimming from 5 to the center of the glass layer 25 having the resistance layer 24 on the lower surface by laser light to remove a part of the resistance layer 24 and the glass layer 25.
The trimming groove 26 is removed by the trimming at this time.

Next, a lead borosilicate glass paste is screen-printed and dried so as to cover at least the resistance layer 24 and the trimming groove 26, and the belt type continuous firing furnace is used at a temperature of 600 ° C. for a peak time of 6 minutes. , IN
The protective layer 27 is formed by firing according to the firing profile of -OUT time 50 minutes.

Next, as a preparatory step for forming the end face electrodes, the collective substrate is divided into strips to expose the end face electrodes to obtain strip substrates (not shown).

Next, the upper surface electrode layer 2 is formed on the side surface of the strip substrate.
2 and the back surface electrode layer 23, the thick film silver paste was applied by a roller so as to be electrically connected, and the temperature was set to about 600 ° C. in a belt type continuous baking furnace at a peak time of 6 minutes, I
The side surface electrode layer 28 is formed by firing according to a firing profile of N-OUT time of 45 minutes.

Next, as a preparatory step for electrode plating, the strip-shaped substrate on which the side surface electrode layer 28 has been formed is divided into individual pieces, and individual pieces of the substrate 21 are obtained to form a resistor body.

Finally, the Ni plating layer 2 is formed by electrolytic barrel plating so as to cover the side surface electrode layer 28, in order to prevent electrode erosion during soldering and to secure reliability of soldering.
9 and a solder (Sn-Pb) plating layer 30 are formed to manufacture a resistor.

A resistor according to one embodiment of the present invention is manufactured below, and the result of comparing the moisture resistance load life characteristic with the conventional resistor is shown in (Table 1). As the test method, a cycle in which the rated voltage was turned on for 1.5 hours and turned off for 0.5 hours was repeated for 5000 hours in a thermo-hygrostat having a temperature of 60 ° C. and a humidity of 90% to 95%. Prototype sample is 3.2mm ×
A 1.6 mm (rated power 1/8 W) resistor with a resistance of 1
00 (10Ω) and 103 (10 kΩ).

[0036]

[Table 1]

As is clear from (Table 1), the present embodiment shows almost no change in resistance value even after being left for 5000 hours in a high temperature and high humidity atmosphere, and has high reliability with excellent resistance to humidity load life. It can be seen that

Although the glass paste is used for the protective layer in the embodiment of the present invention, the same effect can be obtained by using an insulating resin paste.

[0039]

As described above, according to the present invention, the adhesion of the protective layer in the vicinity of the trimming groove is improved, and even if the protective layer is left in a humid atmosphere for a long time, problems such as resistance value change due to infiltration of moisture are eliminated, and the moisture-proof life is improved. It is possible to provide a resistor having excellent characteristics and high reliability.

[Brief description of drawings]

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

FIG. 2 is a cutaway top view in which a protective layer, which is the main part, is removed.

FIG. 3 is a sectional view of a conventional resistor.

FIG. 4 is a top view of a notch in which a protective layer, which is the main part, is removed.

[Explanation of symbols]

 21 Substrate 22 Top Electrode Layer 24 Resistive Layer 25 Glass Layer 26 Trimming Groove 27 Protective Layer 28 Side Electrode Layer

Claims (3)

[Claims] 1. A substrate, a pair of upper surface electrode layers provided on a side of an upper surface of the substrate, a resistance layer provided so as to be electrically connected to the upper surface electrode layer, and an upper surface of the resistance layer. And a trimming groove formed by printing the glass layer and a resistance layer from the upper surface of the glass layer, and a protective layer that covers at least the glass layer and the trimming groove. A side electrode provided on a side surface of the substrate so as to be electrically connected to the upper electrode layer. 2. The resistor according to claim 1, wherein the glass layer is provided so as to cover the entire upper surface of the resistance layer and cover a part of the substrate. 3. The trimming groove is provided from the end portion of the glass layer having a resistance layer directly below to the center, or in the center of the glass layer having a resistance layer directly below the glass layer covering a part of the substrate. The resistor according to claim 1, which is provided facing toward the resistor.