JPH11204302A - Resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resistor, the mounting area of which can be reduced when the resistor is mounted on a mounting substrate, and which has a highly accurate resistance value. SOLUTION: A resistor consists of first upper electrode layers 22 which are provided on the side sections of the main surface of a substrate 21, a resistance layer 23 which is electrically connected to the electrode layers 22, a protective layer 24 provided on the upper surface of the resistance layer 23, and second upper-surface electrode layers 25 which are provided on the upper surfaces of the first upper electrode layers 22 and parts of the side faces of the substrate 21. The first upper electrode layers 22 are connected directly electrically to plated nickel layers 27 in clearance sections 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor.

[0002]

2. Description of the Related Art The prior art is disclosed in Japanese Patent Laid-Open No. 4-102302.
The one disclosed in Japanese Patent Application Laid-Open Publication No. H10-260, 1993 is known.

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

FIG. 6 is a sectional view of a conventional resistor. In the figure, reference numeral 1 denotes an insulating substrate. Reference numeral 2 denotes a pair of first upper electrode layers provided on both left and right ends of the upper surface of the insulating substrate 1. Reference numeral 3 denotes a resistance layer provided so as to partially overlap the first upper electrode layer 2. Reference numeral 4 denotes a first protective layer provided so as to cover only the resistance layer 3 entirely. Reference numeral 5 denotes a trimming groove provided in the resistance layer 3 and the first protection layer 4 for correcting the resistance value. Reference numeral 6 denotes 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. 8 is a side 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, the conventional resistor has the second protective layer 6
Is the highest provided.

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

FIG. 7 is a process chart showing a conventional method for manufacturing a resistor. First, as shown in FIG.
The first upper surface electrode layer 2 is formed by coating on both left and right ends of the upper surface of the substrate.

Next, as shown in FIG. 7B, a resistive layer 3 is applied on the upper surface of the insulating substrate 1 so as to partially overlap the first upper electrode layer 2.

[0008] Next, as shown in FIG.
After forming the first protective layer 4 by coating so as to cover only the entire surface of the resistive layer 3, the resistive layer 3 and the first protective layer 4 are protected by a laser or the like so that the total resistance value of the resistance layer 3 falls within a predetermined resistance value range. The layer 4 is provided with a trimming groove 5.

Next, as shown in FIG. 7D, a second protective layer 6 is formed by coating only on the upper surface of the first protective layer 4.

Next, as shown in FIG. 7E, a second upper electrode layer 7 is formed on the upper surface of the first upper electrode layer 2 so as to extend to the full width of the insulating substrate 1.

Next, as shown in FIG. 7 (f), the first upper electrode layer 2 and the first and second upper electrode layers 2, 7 are electrically connected to the left and right side surfaces of the insulating substrate. The side electrode layer 8 is formed by coating as described above.

Finally, after nickel plating is applied to the surfaces of the second upper electrode layer 7 and the side electrode layer 8, a nickel plating layer 9 and a solder plating layer 10 are formed by applying solder plating. Was manufacturing resistors.

[0013]

However, in the resistor according to the above-described conventional configuration and manufacturing method, when soldering is performed on a mounting board, a cross-sectional view of FIG. As shown in FIG. 8, a fillet mounting structure in which a fillet 11 is formed by soldering both a side electrode layer (not shown) and a lower electrode layer (not shown), and the conventional resistance shown in FIG. As shown in the top view for explaining the mounting state of the container, an area 13 for soldering the side surface is required in addition to the component area 12, and a mounting area 14 in which these are combined is required. In addition, as the external dimensions of the component become smaller, the proportion of the soldering area to the mounting area increases in order to increase the mounting density, and there is a limit in improving the mounting density for miniaturizing electronic devices. Had.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a resistor capable of reducing a soldering area in a mounting area when mounted on a mounting board.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a substrate, a pair of first upper electrode layers provided on the upper surface of the substrate, and an electric device comprising: a first upper electrode layer; A resistive layer provided so as to be electrically connected, a resin-based protective layer provided so as to cover at least the resistive layer, and at least a part of an upper surface of the first upper electrode layer and a part of a side surface of the substrate. The resistor comprising a resin-based second upper electrode layer provided and a plating layer provided so as to cover at least the second upper electrode layer which is exposed,
The upper electrode layer and the plating layer are directly conductive.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, there is provided a semiconductor device comprising: a substrate; a pair of first upper electrode layers provided on an upper surface of the substrate; A resistive layer provided so as to be connected to the first conductive layer, a resin-based protective layer provided so as to cover at least the resistive layer, and provided at least over a top surface of the first upper electrode layer and a part of a side surface of the substrate. And a plating layer provided so as to cover at least the exposed second upper electrode layer, and the first upper electrode layer and the plating layer are directly connected to each other. It is made.

Further, the invention described in claim 2 is the first invention.
, A gap is provided between the protective layer and the second upper electrode layer, and the first upper electrode layer and the plating layer are directly conductive at the gap.

Further, the invention according to claim 3 provides the invention according to claim 1.
And a window portion is provided on the upper surface of the first upper electrode layer, and the first upper electrode layer and the plating layer are directly conductive at the window portion.

The invention described in claim 4 is the first invention.
The second upper surface electrode layer provided on the side surface of the substrate described in (1) is provided on the resistance layer side in the height direction of the substrate.

The invention described in claim 5 is the same as the invention in claim 4.
The area of the second upper electrode layer on the side surface of the substrate described in (1) is not more than half the area of the side surface of the substrate.

The invention described in claim 6 is the first invention.
The plating layer and the protective layer described in (1) above are flush or the plating layer is higher than the protective layer.

The invention described in claim 7 is the first invention.
The first upper electrode layer described in 1 above is made of either silver or gold-based conductive powder containing glass or a gold-based organometallic compound fired, The electrode layer is made of silver or nickel based conductive powder containing resin.

The invention described in claim 8 is the first invention.
The first upper electrode layer is formed by nickel-based or gold-based sputtering, the second upper electrode layer is made of silver or nickel-based conductive powder containing a resin, and the protective layer is made of a resin. It consists of a system.

According to this structure, the resistor has a function of reducing the soldering area occupying the mounting area when mounted on the mounting board.

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

FIG. 1 is a sectional view of the resistor according to the first embodiment of the present invention. In the figure, 21 is a substrate containing 96% alumina. Reference numeral 22 denotes a pair of first upper electrode layers each containing glass in a silver-based conductive powder provided on a side portion of the upper surface of the substrate. 23 is the first upper electrode layer 2
2 is a resistance layer containing ruthenium oxide as a main component and electrically connected to the resistance layer 2. Reference numeral 24 denotes a protective layer made of an epoxy resin provided so as to cover the upper surface of the resistance layer 23. 25 is the first
This is a second upper electrode layer comprising a silver-based conductive powder provided over the upper surface of the upper electrode layer 22 and a part of the side surface of the substrate 21 and containing an epoxy resin. At this time, the substrate 21
The area of the second upper surface electrode layer 25 on the side surface is not more than half the area of the side surface of the substrate 21. Reference numeral 26 denotes a gap between the protective layer 24 and the second upper electrode layer 25. Reference numerals 27 and 28 denote a nickel plating layer and a solder plating layer provided as necessary to ensure reliability and the like during soldering. In the gap 26, the first upper electrode layer 22 and the nickel plating layer 27 are in direct conduction.

The method of manufacturing the resistor according to the first embodiment of the present invention configured as described above will be described below with reference to the drawings.

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

First, as shown in FIG. 2 (a), a plurality of vertical and horizontal dividing grooves 29 and 30 provided on the surface for dividing into strips and individual pieces in a post-process are provided. An electrode paste containing silver-based conductive powder and glass is printed without straddling the horizontal dividing grooves 30 of the sheet-like substrate 21 containing 96% alumina having excellent insulating properties, and is stable. The first upper electrode layer 22 is formed by firing at a temperature of about 850 ° C. in order to form a thin film. The depth of the dividing grooves 29 and 30 with respect to the thickness of the substrate 21 is formed to be half or less of the thickness of the substrate 21 so as not to be broken during handling in a manufacturing process.

Next, as shown in FIG. 2B, a resistive paste containing ruthenium oxide as a main component is printed so as to be electrically connected to the first upper electrode layer 22 to form a stable film. For this purpose, the resistive layer 23 is formed by firing at a temperature of about 850 ° C.

Next, as shown in FIG.
In order to correct the resistance value of No. 3 to a predetermined value, trimming is performed by forming a trimming groove 31 with a YAG laser or the like. At this time, the trimming probe for measuring the resistance value is set on the first upper electrode layer 22 to perform trimming.

Next, as shown in FIG. 3A, a screen paste of a resin paste made of an epoxy resin or the like is printed to protect the resistance layer 23 having the corrected resistance value.
In order to form a stable film, the protective layer 24 is formed by heat curing in a belt-type continuous curing furnace at about 200 ° C. with a profile of about 30 minutes. At this time, a print pattern of the protective layer 24 may be formed so as to continuously cover the plurality of resistance layers 23 arranged in the horizontal direction across the vertical division grooves 29.

Next, as shown in FIG. 3B, on the upper surface of the first upper electrode layer 22, the width direction extends to the full width of the substrate 21, and the lateral dividing grooves 30 of the sheet-like substrate 21 are formed. Straddling,
In addition, an electrode paste made of an epoxy resin or the like using silver, nickel or the like as a conductive powder is screen-printed so as not to overlap with the protective layer 24 in the longitudinal direction to form a stable film. In order to firmly adhere to the upper electrode layer 22, a continuous curing oven of about 200
At 30 ° C. with a profile of about 30 minutes
Of the upper electrode layer 25 is formed. At this time, the electrode paste enters the lateral dividing grooves 30, and the second upper electrode layer 25 can be formed to the depth of the dividing grooves. At this time, the vertical dividing grooves 2 are formed on the plurality of first upper electrode layers 22 arranged in the horizontal direction.
The print pattern of the second upper surface electrode layer 25 may be formed so as to be continuous over 9.

Next, as shown in FIG. 3C, the first upper electrode 22, the resistive layer 23, the trimming groove 31, the protective layer 2
4. Sheet-like substrate 2 on which second upper electrode layer 25 has been formed
1 along the dividing groove 30 in the horizontal direction.
Divided into At this time, the second upper surface electrode layer 25 formed earlier is formed on the longitudinal side surface of the strip substrate 32 to the depth of the lateral dividing groove 30.

Finally, as shown in FIG. 3D, as a preparation step for plating the exposed second upper surface electrode layer 25, along a vertical dividing groove 29 of the strip substrate 32, The substrate is divided into individual substrates 33. Then, in order to prevent electrode erosion during soldering of the exposed second upper surface electrode layer 25 and ensure reliability during soldering, a nickel plating layer (not shown) is formed by electroplating. A resistor is manufactured by forming a solder plating layer (not shown) as an outermost layer.

The resistor constructed and manufactured in the first embodiment of the present invention was soldered to a mounting board.

As shown in the cross-sectional view of FIG. 4A for explaining the mounting state of the resistor according to the embodiment of the present invention, the mounting is performed with the surface on which the protective layer 24 is formed facing downward, and the upper electrode layer ( (Not shown) and the resistance layer portion on the side surface of the substrate, but the fillet 34 is formed only slightly because the area where the side electrode is formed is small. Therefore, as shown in the top view of the mounted state of the resistor in the embodiment of the present invention in FIG.
The area obtained by adding the area 36 required for soldering the side surface to the side is the mounting area 37. 0.6 × 0.3mm
When the mounting area of a square chip resistor having a size is compared with that of a product having a conventional structure, the size can be reduced by about 20%.

Therefore, according to the structure of the present invention, since the area of the side electrode of the resistor is small, the area for forming the fillet for soldering on the mounting substrate can be small, and the mounting area can be reduced. Can be.

The second upper electrode layer is formed of a resin-based conductive material. If the epoxy-based resin uses silver as a conductive powder, it is approximately 10 ^-4 Ωcm, and the epoxy-based resin uses nickel as a conductive powder. Then, the conductor resistance is as high as about 10 ^-2 Ωcm (in contrast, nickel plating and silver glaze material
About 10 ^-6 [Omega] cm), the formation thickness varies, the conductor resistance value of the first upper surface results in a predetermined appended resistance value drift in the resistance value obtained in cropped, which confirm the resistance Electrode layer 22 and nickel plating layer 27 having low conductor resistance
However, since it is directly conducted in the gap 26, the resistor is not affected by the second upper electrode layer 25 having a high conductor resistance, and a highly accurate resistor can be stably manufactured.

In the first embodiment of the present invention, the first upper electrode layer and the nickel plating layer are directly connected to each other. However, the present invention is not limited to the nickel plating layer, but may be a solder plating layer or a resistor. A similar effect can be obtained by using a material having a low conductor resistance that does not affect the resistance value of.

Although the resistance layer 23 is formed of a ruthenium oxide glaze material, the material of the resistance layer is not limited. For example, a similar effect can be obtained in the case of a resistance layer made of a nichrome thin film material.

Further, the solder plating layer 28 and the protective layer 24 are flush with each other or the solder plating layer 28 is made higher, so that a gap between the solder plating layer 28 and the land pattern at the time of mounting is less likely to be generated, and the mounting quality is further improved. be able to.

It is easily conceivable that the mounting area can be further reduced by not forming the side electrode. However, in the current manufacturing process of electronic devices, soldering inspection after mounting is actually performed by image recognition. If side electrodes are not formed, fillets are not formed at all and automatic inspection by image recognition is performed. Will be impossible.

In the first embodiment of the present invention, the first
When the upper electrode layer 22, the protective layer 24, and the second upper electrode layer 25 are combined as shown in (Table 1), other characteristics ((Table 1)) can be improved.

[0045]

[Table 1]

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

FIG. 5 is a sectional view of a resistor according to the second embodiment of the present invention. In the drawing, 41 is a substrate containing 96% alumina. Reference numeral 42 denotes a first silver-based conductive powder which is provided on the side of the main surface of the substrate and contains glass.
Of the upper electrode layer. Reference numeral 43 denotes a resistance layer containing ruthenium oxide as a main component and electrically connected to the first upper electrode layer 42. Reference numeral 44 denotes a protective layer made of an epoxy resin provided on the upper surface of the resistance layer 43. 45 is the first upper electrode layer 42
And a second upper electrode layer made of a silver-based conductive powder provided on a part of the side surface of the substrate 41 and containing an epoxy resin. Second upper electrode layer 45 on the side surface of substrate 41
Is less than half the area of the side surface of the substrate 41. 4
Reference numeral 6 denotes a window between the protective layer 44 and the second upper electrode layer 45. Reference numerals 47 and 48 denote a nickel plating layer and a solder plating layer provided for securing reliability and the like at the time of soldering as necessary. In the window portion 46, the first upper electrode layer 4
2 and the nickel plating layer 47 are in direct conduction.

In the method of manufacturing the resistor according to the second embodiment of the present invention, the window 46 is formed by using a screen printing mask provided with a window when the second upper electrode layer 45 is formed. Except for using and forming a print, it is the same as the manufacturing method of the above-described first embodiment, and thus the description is omitted.

The effect of soldering the resistor according to the second embodiment of the present invention to a mounting board is also the same as that of the first embodiment, and therefore the description is omitted.

[0050]

As described above, according to the present invention, since the upper surface electrode and the side electrode provided on a part of the side surface of the upper surface of the substrate are soldered, the area for forming the soldered fillet is reduced. Accordingly, it is possible to provide a resistor capable of reducing a mounting area including a soldered portion on a mounting board.

Further, since the first upper electrode layer having the determined resistance value and the nickel plating layer having a low conductor resistance are directly conducted in the gap or the window, the second upper electrode layer having a high conductor resistance is provided.
And a stable high-precision resistor can be provided without being affected by the upper electrode layer.

[Brief description of the drawings]

FIG. 1 is a sectional view of a resistor according to a first 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. 4A is a cross-sectional view illustrating the mounting state. FIG. 4B is a top view illustrating the mounting state.

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

FIG. 6 is a sectional view of a conventional resistor.

FIG. 7 is a process chart showing the manufacturing method.

FIG. 8A is a cross-sectional view illustrating the mounting state. FIG. 8B is a top view illustrating the mounting state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Substrate 22 1st upper surface electrode layer 23 Resistance layer 24 Protective layer 25 2nd upper surface electrode layer 26 Gap part 27 Nickel plating layer 28 Solder plating layer

Claims (8)

[Claims] A substrate, a pair of first upper electrode layers provided on an upper surface of the substrate, and a resistive layer provided to be electrically connected to the first upper electrode layer; A resin-based protective layer provided so as to cover the resistance layer; and a resin-based second upper electrode layer provided at least over an upper surface of the first upper electrode layer and a part of a side surface of the substrate. A resistor comprising: a plating layer provided so as to cover the exposed second upper electrode layer; and the first upper electrode layer and the plating layer are in direct conduction. 2. The resistor according to claim 1, wherein a gap is provided between the protective layer and the second upper electrode layer, and the first upper electrode layer and the plating layer are directly connected to each other at the gap. vessel. 3. A window is provided on an upper surface of the first upper electrode layer,
The resistor according to claim 1, wherein the first upper electrode layer and the plating layer are directly connected to each other at the window. 4. The resistor according to claim 1, wherein the second upper electrode layer provided on the side surface of the substrate is provided on the resistance layer side in the height direction of the substrate. 5. The resistor according to claim 4, wherein the area of the second upper electrode layer on the side surface of the substrate is equal to or less than half the area of the side surface of the substrate. 6. The resistor according to claim 1, wherein the plating layer and the protection layer are flush with each other or the plating layer is higher than the protection layer. 7. The first upper electrode layer is made of either silver or gold-based conductive powder containing glass or a gold-based organometallic compound fired. 2. The resistor according to claim 1, wherein the upper electrode layer comprises silver or nickel-based conductive powder containing a resin. 8. The first upper electrode layer is formed by nickel-based or gold-based sputtering, and the second upper electrode layer is made of silver or nickel-based conductive powder containing a resin. The resistor according to claim 1, wherein the resistor is made of a resin.