JPH09320803A - Resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable mounting on a mounting board with respect to any of upper and lower surfaces of a board of a resistor, by providing a lateral electrode layer which is electrically connected with the lateral side of the board by being superimposed on a part of an upper surface of an upper electrode layer, with the superimposed portion protruding from a protection layer. SOLUTION: On a lateral portion of an upper surface of an alumina board 21, a pair of upper electrode layers 22 are provided up to the lateral end of the board 21. A resistor layer 23 is provided on the upper surface of the board 21 in such a manner, as to be superimposed on and electrically connected with the upper electrode 22. In addition, a protection layer 24 made of borosilicated lead glass or the like is provided to cover at least the upper surface of the resistor layer 23. Then, a lateral electrode layer 25 having a round contour is provided, in such a manner as to be electrically connected with the lateral surface of the board 21 by being superimposed on a part of the upper surface of the upper electrode layer 22, with the superimposed portion protruding from the protection layer 24. In addition, a barrier layer 26 is provided to cover the lateral electrode layer 25, and a solder layer 27 having a round contour is provided to cover the barrier layer 26.

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 is disclosed in Japanese Patent Laid-Open No. 10230/1992.
The one disclosed in No. 2 is known.

A conventional resistor and a method for manufacturing the same will be described below with reference to the drawings.

FIG. 8 is a sectional view of a conventional resistor. FIG.
In, 1 is an insulating substrate. Reference numeral 2 is a first upper surface electrode layer provided on the left and right ends of the upper surface of the insulating substrate 1. 3
Is a resistance layer provided so as to partially overlap the first upper surface electrode layer 2. Reference numeral 4 denotes a first protective layer provided so as to cover only the entire resistive layer 3. Reference numeral 5 is a trimming groove provided in the resistance layer 3 and the first protective layer 4 for correcting the resistance value. Reference numeral 6 is a second protective layer provided only on the upper surface of the first protective layer 4. Reference numeral 7 denotes a second upper electrode layer provided on the upper surface of the first upper electrode layer 2 so as to extend to the full width of the insulating substrate 1. Reference numeral 8 denotes a side surface electrode layer provided on the side surface of the insulating substrate 1. Reference numerals 9 and 10 denote nickel plating layers and solder plating layers provided on the surfaces of the second upper electrode layer 7 and the side electrode layers 8, respectively. At this time, the solder plating layer 10 is provided lower than the second protective layer 6. That is, in the conventional resistor, the second protective layer 6 is provided highest.

[0005]

However, in the above-mentioned conventional structure, since the second protective layer 6 is provided higher than the solder plating layer 10, only the lower surface of the insulating substrate 1 of the resistor is mounted on the mounting substrate. There is a problem that it cannot be mounted on a mounting board (not shown) and cannot be automatically mounted on a mounting board by a collective mounting machine such as bulk mounting which mounts the resistor regardless of the upper and lower surfaces.

The present invention solves the above problems, and an object of the present invention is to provide a resistor which can be mounted on a mounting substrate on either the upper or lower surface of the substrate of the resistor.

[0007]

In order to achieve the above-mentioned object, the present invention is designed so that a part of the upper surface of the upper electrode layer is superposed on the side surface of the substrate and electrically connected to the side surface of the substrate, and the superposed portion is the protection layer. And a side surface electrode layer provided so as to project from the layer.

[0008]

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. And the protective layer provided so as to cover at least the resistive layer, and the electrical connection is made by superposing on the upper surface of a part of the upper surface electrode layer on the side surface of the substrate. And a side surface electrode layer provided so as to project from the protective layer.

The invention according to claim 2 includes a substrate,
A pair of upper and lower electrode layers respectively provided on the upper and lower sides of the substrate, a resistive layer electrically connected to the upper electrode layer, and at least the resistive layer. A protective layer is provided and is provided on the side surface of the substrate so as to overlap and electrically connect to the upper surfaces of the back electrode layer and a part of the upper electrode layer, and the overlapped portion protrudes from the protective layer. And a side electrode layer formed on the side surface.

The invention described in claim 3 is the same as claim 1
Alternatively, the side surface electrode layer, which is superposed on the upper surface electrode layer described in 2, is protruded by 5 μm or more from the protective layer.

The invention described in claim 4 is the same as claim 1.
Alternatively, the side surface electrode layer described in 2 is provided so as to overlap a part of the upper surface of the protective layer.

The invention described in claim 5 is the same as the invention in claim 4.
The protective layer described is provided so as to cover a part or all of the upper surface of the upper electrode layer.

With the above structure, the resistor can be mounted on the mounting substrate on either the upper or lower surface of the substrate.

(First Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a resistor according to an embodiment of the present invention. In FIG. 1, reference numeral 21 is a substrate made of alumina or the like. Reference numeral 22 denotes a pair of upper surface electrode layers made of a mixed material of silver and glass, which are provided on the side portions of the upper surface of the substrate 21, and are preferably provided up to the side edges of the substrate 21. Reference numeral 23 is a resistance layer made of a mixed material of ruthenium oxide and glass and provided on the upper surface of the substrate 21 so as to overlap with the upper surface electrode layer 22 so as to be electrically connected. Reference numeral 24 is a protective layer made of lead borosilicate glass or the like provided so as to cover at least the upper surface of the resistance layer 23. 25 is the substrate 2
A side surface made of a mixed material of silver and glass or the like, which is provided so as to overlap a part of the upper surface of the upper surface electrode layer 22 and electrically connect to the side surface of the upper side electrode 1 and to project the overlapping portion from the protective layer 24. In the electrode layer, the ridgeline of the side surface electrode layer 25 is
It has roundness. Reference numeral 26 is a barrier layer made of nickel plating or the like, which is provided so as to cover the side surface electrode layer 25 if necessary. Reference numeral 27 denotes a solder layer provided so as to cover the barrier layer 26 if necessary, and preferably the ridge line of the solder layer 27 has a roundness.

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

2 and 3 are process diagrams showing a method of manufacturing a resistor according to an embodiment of the present invention.

First, as shown in FIG. 2A, a mixed paste material of silver and glass is screen-printed and dried so as to straddle the dividing grooves 31 of a sheet 32 made of alumina or the like having vertical and horizontal dividing grooves 31. Then, the upper surface electrode layer 33 is formed by firing in a belt type continuous firing furnace at a temperature of about 850 ° C. with a profile of about 45 minutes.

Next, as shown in FIG. 2B, a mixed paste material of ruthenium oxide and glass is superposed on a part of the upper electrode layer 33 so as to electrically connect the upper electrode layers 33. As described above, the resistance layer 3 is screen-printed on the upper surface of the sheet 32, dried, and fired in a belt-type continuous firing furnace at a temperature of about 850 ° C. with a profile of about 45 minutes.
4 is formed.

Next, as shown in FIG. 2C, the resistance layer 3
In order to correct the resistance value of No. 4, the trimming groove 35 is formed by trimming with a laser or the like. At this time, before trimming, at least a precoat (not shown) of glass or the like may be performed, and then the precoat and the resistance layer 34 may be trimmed from the upper surface of the precoat by laser or the like to form the trimming groove 34.

Next, as shown in FIG. 2D, the resistance layer 3
The lead borosilicate glass paste was screen-printed and dried so as to completely cover the upper surface of No. 4, and baked by a belt type continuous baking furnace at a temperature of about 850 ° C. for about 45 minutes to form the protective layer 36. Form.

Next, as shown in FIG. 3A, a strip-shaped substrate 37 is formed by dividing along the dividing groove 31 of the sheet 32 so that the upper surface electrode layer 33 is exposed from the side surface of the substrate.

Next, as shown in FIG. 3B, a part of the upper surface electrode layer 33 is superposed on the side surface of the strip-shaped substrate 37, and the superposed portion is projected from the protective layer 36. Roller transfer printing and drying of the mixed paste material of silver and glass, about 600 ℃ in the belt type continuous firing furnace
Then, the side surface electrode layer 38 was formed by firing at a temperature of about 45 minutes with a profile of about 45 minutes.

Next, as shown in FIG. 3C, the strip-shaped substrate 37 is divided into individual pieces to form individual substrate 39.

Finally, if necessary, a barrier layer (not shown) made of nickel plating or the like is formed so as to cover the exposed portion of the upper surface electrode layer 33 and the side surface electrode layer 38, and
A solder layer (not shown) made of tin-lead alloy plating or the like is formed so as to cover the barrier layer to manufacture a resistor.

In the embodiment of the present invention, the material of the protective layer has been described as a mixed material of silver and glass, but the same applies to an epoxy resin material or the like.

Further, in the embodiment of the present invention, the material of the side electrode layer is described as a mixed material of silver and glass.
This also applies to nickel-based phenol resin materials and the like.

With respect to the resistors constructed and manufactured as described above, those whose characteristics are compared will be described below.

(Experimental Method) A bulk 1 by 1 cassette was mounted on an automatic mounting machine (Panasert Mv2 manufactured by Matsushita Electric Industrial Co., Ltd.) to perform automatic mounting, and then 1 at 200 to 250 ° C.
Reflow soldering was performed for 0 to 30 seconds, and the resultant was mounted on a mounting board.

At this time, about half are mounted on the upper surface of the resistor. (Judgment of Pass / Fail) Regarding the chip standing, as shown in FIG. 4A, whether or not the solder is attached to only one side of the soldering land pattern was used as a pass / fail judgment criterion.

As for the θ deviation, as shown in FIG. 4B, whether or not the resistor rotates by 0.2 degrees or more on the soldering land pattern is used as a criterion for acceptability.

(Experimental Result 1) In the following, (Table 1) shows experimental results of the dimension of protrusion of the side surface electrode layer from the protective layer and the number of mounting defects.

[0033]

[Table 1]

As is clear from (Table 1), in the resistor according to the present embodiment, the side electrode layer is provided so as to project by 5 μm or more from the protective layer, so that the number of mounting defects is smaller than in the conventional example.

(Second Embodiment) FIG. 5 is a sectional view of a resistor according to another embodiment of the present invention.

In FIG. 5, reference numeral 51 is a substrate made of alumina or the like. Reference numeral 52 denotes a pair of upper surface electrode layers made of a mixed material of silver and glass or the like, which is provided on the side portion of the upper surface of the substrate 51, and is preferably provided up to the side edge of the substrate 51.
Reference numeral 53 denotes a pair of back electrode layers made of a mixed material of silver and glass and provided on the side surface of the lower surface of the substrate 51, preferably provided up to the side edges of the substrate 51. 54 is a substrate 51
Is a resistance layer made of a mixed material of ruthenium oxide and glass and provided on the upper surface of the above so as to overlap with the upper surface electrode layer 52 and be electrically connected. Reference numeral 55 is a protective layer made of lead borosilicate glass or the like provided so as to cover at least the upper surface of the resistance layer 54. 56 is a mixed material of silver and glass, which is provided on the side surface of the substrate 51 so as to overlap with and electrically connect to a part of the upper surface of the upper electrode layer 52, and the overlapped portion projects from the protective layer 55. The side surface electrode layer is made of, and the ridge line of the side surface electrode layer 56 has a roundness.
Reference numeral 57 is a barrier layer made of nickel plating or the like provided so as to cover the side surface electrode layer 56 as necessary. Reference numeral 58 denotes a solder layer provided so as to cover the barrier layer 57 if necessary, and preferably the ridge line of the solder layer 58 has a roundness.

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

6 and 7 are process drawings showing a method of manufacturing a resistor according to another embodiment of the present invention.

First, as shown in FIG. 6A, a sheet 6 made of alumina or the like having vertical and horizontal dividing grooves 61 on its upper and lower surfaces.
The mixed paste material of silver and glass is screen-printed and dried so as to straddle the two dividing grooves 61, and this sheet 62 is inverted to form a mixture of silver and glass so as to straddle the dividing grooves (not shown) of the sheet 62. The mixed paste material is screen-printed, dried, and fired in a belt-type continuous firing furnace at a temperature of about 850 ° C. with a profile of about 45 minutes to form a top electrode layer 63 and a back electrode layer 64.

Next, as shown in FIG. 6B, a mixed paste material of ruthenium oxide and glass is superposed on a part of the upper surface electrode layer 63 so as to electrically connect the upper surface electrode layers 63. As described above, the upper surface of the sheet 32 is screen-printed, dried, and fired in a belt-type continuous firing furnace at a temperature of about 850 ° C. with a profile of about 45 minutes to form the resistance layer 6
5 is formed.

Next, as shown in FIG. 6C, the resistance layer 6
In order to correct the resistance value of No. 5, the trimming groove 66 is formed by trimming with a laser or the like. At this time, before trimming, at least after precoating (not shown) with glass or the like, the precoat and the resistance layer 65 may be trimmed from the upper surface of the precoat with a laser or the like to form the trimming groove 66.

Next, as shown in FIG. 6D, the resistance layer 6
The lead borosilicate glass paste was screen-printed and dried so as to completely cover the upper surface of No. 5, and fired in a belt-type continuous firing furnace at a temperature of about 850 ° C. for about 45 minutes to form a protective layer 67. Form.

Next, as shown in FIG. 7A, the strip-shaped substrate 68 is formed by dividing the sheet 62 along the dividing groove 61 so that the upper surface electrode layer 63 is exposed from the side surface of the substrate.

Next, as shown in FIG. 7B, a part of the upper surface electrode layer 63 is overlapped with the side surface of the strip-shaped substrate 68, and the overlapped part is projected from the protective layer 67. Roller transfer printing and drying of the mixed paste material of silver and glass, about 600 ℃ in the belt type continuous firing furnace
The side electrode layer 69 was formed by firing at a temperature of about 45 minutes according to a profile of about 45 minutes.

Next, as shown in FIG. 7C, the strip-shaped substrate 68 is divided into individual pieces to form individual piece-shaped substrates 70.

Finally, if necessary, a barrier layer (not shown) made of nickel plating or the like is formed so as to cover the exposed portion of the upper surface electrode layer 63 and the side surface electrode layer 69.
A solder layer (not shown) made of tin-lead alloy plating or the like is formed so as to cover the barrier layer to manufacture a resistor.

Although the material of the protective layer has been described as a mixed material of silver and glass in the embodiment of the present invention, the same effect can be obtained by using an epoxy resin material or the like.

In the embodiment of the present invention, the material of the side electrode layer is described as a mixed material of silver and glass, but the same effect can be obtained by using a nickel-based phenol resin material or the like.

With respect to the resistors constructed and manufactured as described above, those whose characteristics are compared will be described below.

(Experimental Method) A bulk 1 by 1 cassette was mounted on an automatic mounting machine (Panasert Mv2 manufactured by Matsushita Electric Industrial Co., Ltd.) to carry out automatic mounting, and then 1 at 200 to 250 ° C.
Reflow soldering was performed for 0 to 30 seconds, and the resultant was mounted on a mounting board.

At this time, about half are mounted on the upper surface of the resistor. (Judgment of Pass / Fail) Regarding the chip standing, as shown in FIG. 4A, whether or not the solder is attached to only one side of the soldering land pattern was used as a pass / fail judgment criterion.

As for the θ deviation, as shown in FIG. 4B, whether or not the resistor rotates 0.2 degrees or more on the soldering land pattern is used as a criterion for acceptability.

(Experimental Result 2) In the following, (Table 2) shows experimental results of the dimension of protrusion of the side surface electrode layer from the protective layer and the number of mounting defects.

[0054]

[Table 2]

As is clear from (Table 2), in the resistor according to the present embodiment, the side electrode layer is provided so as to project from the protective layer by 5 μm or more, so that the number of mounting defects is smaller than that of the conventional resistor.

[0056]

As described above, according to the present invention, since the side surface electrode layer is provided so as to protrude from the protective layer, it is possible to provide a resistor which can be mounted on the mounting substrate on either the upper or lower surface of the resistor. It is a thing.

[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 process chart showing the manufacturing method.

FIG. 3 is a process chart showing the manufacturing method.

FIG. 4 is a diagram for explaining a defect example in the same mounting experiment.

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

FIG. 6 is a process chart showing the manufacturing method.

FIG. 7 is a process drawing showing the same manufacturing method.

FIG. 8 is a sectional view of a conventional resistor.

[Explanation of symbols]

 21 substrate 22 upper surface electrode layer 23 resistance layer 24 protective layer 25 side electrode layer

Claims (5)

[Claims] 1. A substrate, a pair of upper surface electrode layers provided on a side portion of an upper surface of the substrate, a resistance layer provided so as to be electrically connected to the upper surface electrode layer, and at least the resistance layer. The protective layer provided so as to cover the upper surface of the upper electrode layer on the side surface of the substrate so as to overlap and electrically connect to the upper surface of the electrode layer, and the overlapping portion is provided so as to protrude from the protective layer. A resistor including a side electrode layer. 2. A substrate, a pair of upper and lower electrode layers respectively provided on upper and lower sides of the substrate, and a resistance layer provided so as to be electrically connected to the upper electrode layer. At least the protective layer provided so as to cover the resistance layer, and on the side surface of the substrate are overlapped on the upper surfaces of the back electrode layer and a part of the top electrode layer to electrically connect, and the overlapped portion is A resistor comprising a side electrode layer provided so as to protrude from the protective layer. 3. The resistor according to claim 1, wherein the side surface electrode layer which is superposed on the upper surface electrode layer projects by 5 μm or more from the protective layer. 4. The resistor according to claim 1, wherein the side surface electrode layer is provided so as to overlap a part of the upper surface of the protective layer. 5. The resistor according to claim 4, wherein the protective layer is provided so as to cover a part or all of the upper surface of the upper electrode layer.