JP2007208029A - Chip resistor, jumper chip resistor, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellently reliable chip resistor capable of preventing a characteristic defect caused by disconnection even if a diffusion reaction is generated in a part where a gold electrode is superimposed on a silver electrode. <P>SOLUTION: The chip resistor includes a substrate 11, a pair of first upper surface electrodes 12 formed at both ends of the upper surface of the substrate 11, a pair of second upper surface electrodes 13 formed so as to be at least partially superimposed on the pair of first upper surface electrodes 12, and a resistor 14 arranged so as to be electrically connected to the pair of second upper surface electrodes 13. The pair of first upper surface electrodes 12 are composed of a conductor with gold as a main component, and the pair of second upper surface electrodes 13 are composed of conductors adopting silver as main components and containing scaly silver powder. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a chip resistor, a jumper chip resistor whose resistance value is low and high reliability is required, and a manufacturing method thereof.

  Hereinafter, a conventional chip resistor will be described with reference to the drawings.

  FIG. 10 shows a cross-sectional view of a conventional chip resistor. In FIG. 10, reference numeral 1 denotes an insulating substrate made of porcelain such as alumina. Gold is applied to the left and right ends of the upper surface of the substrate 1. A pair of first upper surface electrodes 2 as main components is provided. Reference numeral 3 denotes a second upper surface electrode made of granular silver powder provided on the upper surface of the substrate 1 so as to partially overlap the pair of upper surface electrodes 2. Reference numeral 4 denotes a resistor made of a thick film paste provided on the upper surface of the substrate 1 so as to be electrically connected to the pair of second upper surface electrodes 3. Reference numeral 5 denotes an auxiliary upper surface electrode made of resin silver provided so as to electrically connect the pair of first upper surface electrodes 2 and the pair of second upper surface electrodes 3. Reference numeral 6 denotes a protective layer made of a resin covering the resistor 4. Reference numeral 7 denotes an end face electrode made of thin film sputtering provided so as to electrically connect the pair of first upper face electrodes 2 and the pair of auxiliary upper face electrodes 5 to the end face and the back face of the substrate 1. 8 is a plating layer provided on a part of the surface of the pair of second upper surface electrodes 3, the surface of the pair of auxiliary upper surface electrodes 5, and the surface of the pair of end surface electrodes 7, and this plating layer 8 is usually a nickel plating layer. It has a two-layer structure of solder plating layers.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP-A-5-205903

  In the conventional chip resistor described above, the connection between the first upper surface electrode 2 and the second upper surface electrode 3 is ensured as shown in FIG. 11A before firing, but after firing, FIG. ), The silver component of the second upper surface electrode 3 diffuses in the direction of the first upper surface electrode 2 in the overlapping portion of the first upper surface electrode 2 made of gold and the second upper surface electrode 3 made of silver. The first upper surface electrode 2 may be alloyed and the first upper surface electrode 2 and the second upper surface electrode 3 may be disconnected. For this reason, a change occurs in the resistance value, and the rate of occurrence of defective products is high.

  The present invention solves the above-described conventional problems, and even if a diffusion reaction occurs in the overlapping portion of the gold electrode and the silver electrode, it is possible to prevent a defective characteristic due to disconnection, and to provide a highly reliable chip resistor. It is intended to provide.

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, the substrate, the pair of first upper surface electrodes formed at both ends of the upper surface of the substrate, and at least a part of the pair of first upper surface electrodes overlap each other. A pair of formed second upper surface electrodes and a resistor provided so as to be electrically connected to the pair of second upper surface electrodes, the pair of first upper surface electrodes and the pair of second upper surface electrodes. One of them is composed of a conductor mainly composed of gold, and one of the other is composed of a conductor mainly composed of silver and containing scaly silver powder. Since either the upper surface electrode or the second upper surface electrode is composed of a conductor mainly composed of gold, and either one is composed of a conductor mainly composed of silver and containing scaly silver powder, The diffusion reaction from the silver-based conductor to the gold-based conductor is suppressed. As a result, disconnection at the overlapping portion of the first upper surface electrode and the second upper surface electrode is less likely to occur, and therefore, there is an effect that a highly reliable chip resistor can be obtained. .

  The invention according to claim 2 of the present invention is such that the content ratio of palladium in the conductor containing silver as a main component and scaly silver powder is 5% by weight or less. The amount of palladium used can be reduced, which is advantageous in terms of cost. In addition, when the palladium content in the silver electrode is large, the resistance value of the silver electrode itself is increased, so a low resistance value is required. Thus, the present invention has an effect that it can be easily applied to electronic components such as jumper chip resistors that cannot increase the palladium content in the silver electrode.

  The invention according to claim 3 of the present invention is formed so as to bridge the substrate, the pair of first upper surface electrodes made of a gold resinate provided on the upper surface of the substrate, and the pair of first upper surface electrodes. A second upper surface electrode mainly composed of silver and a protective layer covering the second upper surface electrode, and the second upper surface electrode is made of a conductor containing scaly silver powder. According to this, since the second upper surface electrode contains scaly silver powder, the diffusion reaction from the second upper surface electrode to the first upper surface electrode is suppressed even when the content of palladium contained in the second upper surface electrode is small. As a result, disconnection at the overlapping portion of the first upper surface electrode and the second upper surface electrode is less likely to occur, and thus a jumper chip resistor that requires low resistance and high reliability can be obtained. It has the effect of.

  According to a fourth aspect of the present invention, there is provided a step of forming a plurality of first upper surface electrodes made of gold resinate on an upper surface of a sheet-like substrate, and silver so as to partially overlap the plurality of first upper surface electrodes. A step of forming a plurality of second upper surface electrodes mainly composed of the upper surface of the sheet-like substrate, and a slit vertically penetrating the sheet-like substrate so that only the plurality of first upper surface electrodes are cut Forming an end surface electrode on a part of the back side of the sheet-like substrate and the inner wall of the slit, dividing the sheet-like substrate into individual pieces, and the first And a step of forming a plating layer on an exposed portion of the upper surface electrode and the end surface electrode, and the second upper surface electrode is composed of a conductor containing silver as a main component and scaly silver powder. According to the first, consisting of a gold resinate with a thin film thickness Since slits that penetrate the sheet-like substrate in the vertical direction are formed so that only the surface electrodes are cut, burrs are less likely to occur in the first upper surface electrode when the slits are formed, The second upper surface electrode is made of a conductor containing silver as a main component and containing scaly silver powder. Therefore, even if the content of palladium contained in the second upper surface electrode is small, the second upper surface electrode is changed from the second upper surface electrode to the first upper surface electrode. As a result, the disconnection reaction at the overlapping portion of the first upper surface electrode and the second upper surface electrode is less likely to occur, so that a jumper chip resistor having excellent reliability can be obtained. It has the effect of being able to.

  As described above, in the chip resistor of the present invention, one of the first upper surface electrode and the second upper surface electrode is composed of a conductor mainly composed of gold, and one of the other is composed of silver as a main component, and the scale. Therefore, the diffusion reaction from the silver-based conductor to the gold-based conductor is suppressed, whereby the first upper surface electrode Since the disconnection at the overlapping portion between the first upper surface electrode and the second upper surface electrode is less likely to occur, an excellent effect is obtained that a chip resistor having excellent reliability can be obtained.

(Embodiment 1)
Hereinafter, the first and second aspects of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross-sectional view of the chip resistor according to Embodiment 1 of the present invention.

  In FIG. 1, reference numeral 11 denotes an insulating substrate made of porcelain such as alumina, and a pair of first substrates made of gold resinate, which is a conductor mainly composed of gold, on the left and right ends of the upper surface of the substrate 11. A top electrode 12 is provided. Reference numeral 13 denotes a second upper surface electrode provided on the upper surface of the substrate 11 so as to partially overlap the pair of first upper surface electrodes 12, and the second upper surface electrode 13 contains silver as a main component and scaly silver powder. It is comprised with the conductor. Reference numeral 14 denotes a resistor made of a thick film paste such as ruthenium oxide provided on the upper surface of the substrate 11 so as to be electrically connected to the pair of second upper surface electrodes 13. Reference numeral 15 denotes an auxiliary upper surface electrode made of resin silver provided so as to electrically connect the pair of first upper surface electrodes 12 and the pair of second upper surface electrodes 13. Reference numeral 16 denotes a protective layer made of resin that covers all of the resistor 14 and a part of the second upper surface electrode 13. Reference numeral 17 denotes an end face electrode made of thin film sputtering provided on the back and end faces of the substrate 11 so as to be electrically connected to the pair of first upper face electrodes 12 and the pair of auxiliary upper face electrodes 15. Reference numeral 18 denotes a plating layer provided on a part of the surface of the pair of second upper surface electrodes 13, the surface of the pair of auxiliary upper surface electrodes 15 and the surface of the pair of end surface electrodes 17, and this plating layer 18 is usually a nickel plating layer. It has a two-layer structure of solder plating layers.

  In the above-described chip resistor according to the first embodiment of the present invention, the first upper surface electrode 12 is composed of a gold resinate that is a conductor mainly composed of gold, and the second upper surface electrode 13 is composed mainly of silver. Since it is composed of a conductor containing scale-like silver powder, the first upper surface electrode 12 and the second upper surface electrode 13 connected to each other before firing as shown in FIG. As shown in (b), the diffusion reaction from the second upper surface electrode 13 to the first upper surface electrode 12 is suppressed, so that in the overlapping portion between the first upper surface electrode 12 and the second upper surface electrode 13. Since the connection is ensured through the alloy layer 12a of gold and silver, disconnection is unlikely to occur, and thereby, an excellent reliability can be obtained. Further, since the first upper surface electrode 12 is made of a thin gold resinate, even when the first upper surface electrode 12 is diced and cut when the sheet-like substrate is divided into a strip-like substrate or an individual substrate. As a result, it is difficult to generate burrs, and a chip resistor having excellent reliability can be provided.

  FIG. 5 is a characteristic diagram comparing characteristic variations between the conventional chip resistor and the chip resistor according to the first embodiment of the present invention. As is apparent from FIG. 5, the first embodiment of the present invention is shown. In the chip resistor, since the second upper surface electrode 13 is composed of a conductor containing silver as a main component and containing scaly silver powder, the content ratio of palladium compared to a conventional chip resistor using granular silver powder Even if it is as low as 5% by weight or less, there is little variation in characteristics, and this makes it possible to provide a chip resistor with excellent reliability at a low cost.

(Embodiment 2)
The second aspect of the present invention will be described below with reference to the drawings.

  FIG. 2 shows a cross-sectional view of the chip resistor according to the second embodiment of the present invention.

  In FIG. 2, reference numeral 11 denotes an insulating substrate made of porcelain such as alumina, and a pair of first substrates made of gold resinate, which is a conductor mainly composed of gold, on both left and right ends of the upper surface of the substrate 11. A top electrode 12 is provided. Reference numeral 13 denotes a second upper surface electrode provided at an end portion of the pair of first upper surface electrodes 12, and the second upper surface electrode 13 is composed of a conductor containing silver as a main component and scaly silver powder. . Reference numeral 14 denotes a resistor made of a thick film paste such as ruthenium oxide provided on the upper surface of the substrate 11 so as to be electrically connected to the pair of first upper surface electrodes 12. Reference numeral 16 denotes a protective layer made of resin that covers all of the resistor 14, a part of the first upper surface electrode 12, and a part of the second upper surface electrode 13. Reference numeral 17 denotes an end face electrode made of thin film sputtering provided on the back surface and the end face of the substrate 11 so as to be electrically connected to the pair of first top face electrodes 12 and the pair of second top face electrodes 13. Reference numeral 18 denotes a plating layer provided on the surface of the pair of second upper surface electrodes 13 and the surface of the pair of end surface electrodes 17, and this plating layer 18 usually has a two-layer structure of a nickel plating layer and a solder plating layer. Is.

  In the above-described chip resistor according to the second embodiment of the present invention, the first upper surface electrode 12 is composed of a gold resinate that is a conductor mainly composed of gold, and the second upper surface electrode 13 is composed mainly of silver. Since it is composed of a conductor containing scale-like silver powder, the first upper surface electrode 12 and the second upper surface electrode 13 connected to each other before firing as shown in FIG. As shown in (b), the diffusion reaction from the second upper surface electrode 13 to the first upper surface electrode 12 is suppressed, so that in the overlapping portion between the first upper surface electrode 12 and the second upper surface electrode 13. Since the connection is ensured through the alloy layer 12a of gold and silver, disconnection is unlikely to occur, and thereby, an excellent reliability can be obtained. Moreover, since the 1st upper surface electrode 12 which consists of gold resinates is provided in the interface of the protective layer 16 and the 2nd upper surface electrode 13 as a countermeasure against the sulfide disconnection of a silver electrode, the 2nd upper surface electrode 13 which has silver as a main component is provided. Even if the connection is broken by a sulfur atmosphere, conduction can be ensured by the first upper surface electrode 12 made of a gold resinate, whereby a chip resistor having excellent reliability can be obtained particularly in use in a sulfur atmosphere. .

(Embodiment 3)
The third embodiment of the present invention will be described below with reference to the drawings.

  FIG. 3 shows a cross-sectional view of the chip resistor according to Embodiment 3 of the present invention.

  In FIG. 3, reference numeral 11 denotes an insulating substrate made of porcelain such as alumina, and left and right ends of the upper surface of the substrate 11 are a pair of first conductors made of silver and containing a scale-like silver powder. One upper surface electrode 12 is provided. Reference numeral 13 denotes a second upper surface electrode provided on the upper surface of the substrate 11 so as to partially overlap the pair of first upper surface electrodes 12, and the second upper surface electrode 13 is made of a conductor mainly composed of gold. ing. Reference numeral 14 denotes a resistor made of a thick film paste such as ruthenium oxide provided on the upper surface of the substrate 11 so as to be electrically connected to the pair of second upper surface electrodes 13. Reference numeral 16 denotes a protective layer made of resin that covers all of the resistor 14, part of the second upper surface electrode 13, and part of the first upper surface electrode 12. Reference numeral 17 denotes an end face electrode made of thin film sputtering provided on the back and end faces of the substrate 11 so as to be electrically connected to the pair of first upper face electrodes 12. Reference numeral 18 denotes a plating layer provided on the surface of the pair of first upper surface electrodes 12 and the surface of the pair of end surface electrodes 17, and this plating layer 18 is generally composed of a two-layer structure of a nickel plating layer and a solder plating layer. Is.

  In the above-described chip resistor according to the third embodiment of the present invention, the second upper surface electrode 13 is composed of a conductor whose main component is gold, and the first upper surface electrode 12 is a scaly silver powder whose main component is silver. 4 (a), the first upper surface electrode 12 and the second upper surface electrode 13, which are connected to each other before firing, are shown in FIG. 4 (b) even after firing. As shown, the diffusion reaction from the first upper surface electrode 12 to the second upper surface electrode 13 is suppressed, so that gold and silver are overlapped at the overlapping portion of the first upper surface electrode 12 and the second upper surface electrode 13. Therefore, disconnection is unlikely to occur, and an excellent reliability can be obtained. Further, since the second upper surface electrode 13 made of a conductor mainly composed of gold is formed between the first upper surface electrode 12 and the resistor 14, a silver component is formed from the first upper surface electrode 12 to the resistor 14. As a result, a chip resistor with little variation in resistance characteristic and excellent reliability can be obtained.

(Embodiment 4)
Hereinafter, the invention described in the third and fourth aspects of the present invention will be described with reference to the drawings by using the fourth embodiment.

  6 (a) to 6 (c) and FIGS. 7 (a) to 7 (d) show a manufacturing method of the jumper chip resistor according to the fourth embodiment of the present invention. The manufacturing method will be described below.

  First, as shown in FIG. 6A, a first upper surface electrode 12 made of gold resinate is formed in a grid pattern on the upper surface of a sheet-like substrate 11a made of alumina having a purity of about 96%.

  Next, as shown in FIG. 6B, the second upper surface electrode 13 made of a conductor containing silver as a main component and containing scaly silver powder so as to partially overlap the plurality of first upper surface electrodes 12 is formed into a sheet shape. The first upper surface electrode 12 and the second upper surface electrode 13 are formed into stable films by being formed on the upper surface of the substrate 11a and firing with a profile having a peak temperature of 850 ° C.

  Next, as shown in FIG. 6C, a protective layer made of resin in a direction perpendicular to the direction in which the first upper surface electrode 12 and the second upper surface electrode 13 are arranged so as to cover a part of the second upper surface electrode 13. 16 is formed in a strip shape and fired with a profile having a peak temperature of 200 ° C., whereby the protective layer 16 is made a stable film.

  Next, as shown in FIG. 7A, a plurality of slits 11b penetrating the substrate 11a in the vertical direction are formed in the sheet-like substrate 11a by dicing so that only the plurality of first upper surface electrodes 12 are cut. In this case, since the first upper surface electrode 12 is composed of a gold resinate that can be easily thinned, burrs are less likely to occur in the first upper surface electrode 12 when the slit 11b is formed. The characteristics are stable.

  Next, as shown in FIG. 7B, a metal mask 19 having slits 19a having the same interval as the plurality of slits 11b and wider than the width of the slits 11b is arranged on the back surface of the sheet-like substrate 11a. Then, the sputter 20 is irradiated from the back side of the sheet-like substrate 11a to form the end face electrode 17 on a part of the back side of the sheet-like substrate 11a and the inner wall of the slit 11b. At this time, the end surface electrode 17 may be formed so as to go around to the upper surface of the sheet-like substrate 11 a and cover a part of the second upper surface electrode 13.

  Next, as shown in FIG. 7C, the substrate 11a is placed on the sheet-like substrate 11a in a direction orthogonal to the plurality of slits 11b so that the first upper surface electrode 12 and the second upper surface electrode 13 are not cut. A slit 11c penetrating in the vertical direction is formed by dicing to divide the substrate into individual pieces 11d.

  Finally, as shown in FIG. 7D, the plating layer 18 is formed on the exposed portions of the end face electrode 17 (not shown) and the first upper surface electrode 12 (not shown), thereby implementing the present invention. A jumper chip resistor in form 4 is obtained.

  FIG. 8 shows a cross-sectional view of the jumper chip resistor according to the fourth embodiment of the present invention. In the jumper chip resistor according to the fourth embodiment of the present invention, the first upper surface electrode 12 is made of gold. Since the second upper surface electrode 13 is made of a resin and contains a scale-like silver powder, the second upper surface electrode 13 is connected to each other before firing as shown in FIG. As shown in FIG. 4B, the diffusion reaction from the first upper surface electrode 13 to the first upper surface electrode 12 is suppressed even after the first upper surface electrode 12 and the second upper surface electrode 13 are baked. In the overlapping portion of the first upper surface electrode 12 and the second upper surface electrode 13, since the connection is reliably made through the alloy layer 12 a of gold and silver, disconnection hardly occurs, and thereby excellent in reliability. Is what you get .

  FIG. 9 is a characteristic diagram comparing the characteristic variation between the conventional jumper chip resistor and the jumper chip resistor according to the fourth embodiment of the present invention. As is apparent from FIG. The jumper chip resistor in the fourth aspect is configured by the second upper surface electrode 13 made of a conductor containing silver as a main component and containing scaly silver powder, and therefore, compared to a conventional jumper chip resistor using granular silver powder. Even if the content ratio of palladium in the second upper surface electrode 13 made of silver is as low as 5% by weight or less, the characteristic variation is small and a low resistance value is guaranteed. Therefore, a low resistance value and excellent reliability can be obtained. It is obtained.

  The chip resistor according to the present invention uses a scaly silver powder to suppress the diffusion reaction from the silver electrode to the gold electrode, thereby reducing the frequency of occurrence of disconnection failure. This is useful when applied to a chip resistor or a jumper chip resistor.

Sectional drawing of the chip resistor in Embodiment 1 of this invention Sectional drawing of the chip resistor in Embodiment 2 of this invention Sectional drawing of the chip resistor in Embodiment 3 of this invention (A) (b) Partial sectional view comparing the connection state of the gold electrode and the silver electrode of the chip resistor in the first to third embodiments of the present invention before and after firing. The characteristic figure which shows the influence of the content rate of palladium in the conductor material of the chip resistor in the prior art example and Embodiments 1-3 of the present invention (A)-(c) Manufacturing process figure which shows the manufacturing method of the jumper chip resistor in Embodiment 4 of this invention (A)-(d) Manufacturing process figure which shows the manufacturing method of the jumper chip resistor Cross section of the same jumper chip resistor The characteristic figure which shows the influence of the content rate of palladium in the conductor material of the prior art example and the jumper chip resistor in Embodiment 4 of this invention Cross-sectional view of a conventional chip resistor (A) (b) The partial sectional view which compared the connection state of the gold electrode and the silver electrode in the conventional chip resistor before baking and after baking

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Board | substrate 11a Sheet-like board | substrate 11b Slit 11d Single piece board | substrate 12 1st upper surface electrode 13 2nd upper surface electrode 14 Resistor 16 Protective layer 17 End surface electrode 18 Plating layer

Claims (4)

A pair of first upper surface electrodes formed on both ends of the upper surface of the substrate, a pair of second upper surface electrodes formed so as to at least partially overlap the pair of first upper surface electrodes, A resistor provided so as to be electrically connected to the pair of second upper surface electrodes, and one of the pair of first upper surface electrodes and the pair of second upper surface electrodes is mainly composed of gold. A chip resistor composed of a conductor and one of the other composed of a conductor containing silver as a main component and scaly silver powder. The chip resistor according to claim 1, wherein the content ratio of palladium in a conductor containing silver as a main component and containing scaly silver powder is 5 wt% or less. A substrate, a pair of first upper surface electrodes made of a gold resinate provided on the upper surface of the substrate, and a second upper surface electrode mainly composed of silver formed to bridge the pair of first upper surface electrodes; And a protective layer that covers the second upper surface electrode, and the second upper surface electrode is made of a conductor containing scale-like silver powder. Forming a plurality of first upper surface electrodes made of gold resinate on an upper surface of a sheet-like substrate; and a plurality of second upper surface electrodes mainly composed of silver so as to partially overlap the plurality of first upper surface electrodes. Forming on the upper surface of the sheet-like substrate, forming a slit penetrating the sheet-like substrate in the vertical direction so that only the plurality of first upper surface electrodes are cut, and A step of forming an end face electrode on a part of the back side and the inner wall of the slit; a step of dividing the sheet-like substrate into a piece-like substrate; and a plating layer on exposed portions of the first upper face electrode and the end face electrode. And forming the jumper chip resistor, wherein the second upper surface electrode is made of a conductor containing silver as a main component and scaly silver powder.

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