JP2005191206A - Resistor and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide a stable resistor with a small fluctuation in resistance value under voltage load and a method for manufacturing the same.
A substrate, a resistance layer and an upper electrode layer provided so as to be electrically connected to each other on the upper surface side of the substrate, and a protective layer covering the resistance layer and the upper electrode layer. 14, the resistance layer 12 is made of a metal material or a metal oxide material, and the upper electrode layer 13 is made of a CuNi alloy.
[Selection] Figure 1

Description

  The present invention relates to a resistor used in various electronic devices and a method for manufacturing the same.

  A conventional resistor will be described with reference to the drawings. FIG. 5 is a cross-sectional view of a conventional resistor.

  In FIG. 5, reference numeral 1 denotes a substrate made of alumina or the like, and a resistance layer 2 made of a metal material such as a NiCr-based or CrSi-based thin film is formed on the upper surface of the substrate 1, and is positioned on the upper surface side of the resistance layer 2. An upper electrode layer 3 is provided on the upper surface of the substrate 1 so as to be electrically connected to the resistance layer 2. 4 is an end face electrode layer, 5 is a nickel plating layer, 6 is a solder plating layer or tin plating layer, 7 is a protective layer, and 8 is a resin-based protective layer.

  The upper surface electrode layer 3 includes a first upper surface electrode layer 3a made of a Cr thin film, a Ti thin film, or the like that is electrically connected to the resistance layer 2 and has good adhesion to the resistance layer 2, and the first upper surface electrode. The second upper surface electrode layer 3b made of a Cu-based alloy thin film that is electrically connected to the layer 3a and has a volume resistivity lower than that of the first upper surface electrode layer 3a is laminated. It was.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2002-260901 A

  In the conventional resistor described above, when the resistance layer 2 is made of a material containing a metal oxide, the first upper surface electrode layer 3a made of a Cr thin film, a Ti thin film, or the like reacts with oxygen in the resistance layer 2 to be insulated. As a result, the contact resistance between the resistance layer 2 and the first upper surface electrode layer 3a is increased, and the resistance value is reduced due to dielectric breakdown or heat generation during voltage load. There was a problem that it fluctuated greatly.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object thereof is to provide a stable resistor having a small resistance value fluctuation under voltage load and a method for manufacturing the same.

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

  The invention according to claim 1 of the present invention covers a substrate, a resistance layer and an upper electrode layer provided on the upper surface side of the substrate so as to be electrically connected to each other, and the resistance layer and the upper electrode layer. A protective layer, the resistance layer is made of a metal material or a metal oxide material, and the upper electrode layer is made of a CuNi alloy. According to this structure, the upper electrode layer is made of a CuNi alloy. Therefore, Ni in the upper surface electrode layer diffuses into the resistance layer, whereby a strong adhesion layer is formed between the upper surface electrode layer and the resistance layer, and the contact resistance can be further reduced. Therefore, there can be obtained an effect that the resistance value fluctuation at the time of voltage load can be reduced.

  According to the second aspect of the present invention, the resistance layer is made of CrSiO which is a metal oxide material. According to this structure, the resistance layer made of CrSiO and the upper electrode layer made of CuNi alloy Since a strong adhesion layer is formed between the two, an effect of reducing the contact resistance can be obtained.

  In the invention according to claim 3 of the present invention, in particular, the upper electrode layer is composed of a CuNi alloy thin film containing Ni in a proportion of 1.6 wt% to 35 wt% in Cu. Therefore, since the high conductivity that is a characteristic of Cu and the adhesiveness that is a characteristic of Ni can be compatible, there is an effect that an upper electrode layer that has a low wiring resistance and is electrically stable can be provided. can get.

  The invention described in claim 4 of the present invention is particularly configured such that the Ni content in the upper electrode layer is increased in the vicinity of the connection portion with the resistance layer as compared with other portions. For example, high conductivity, which is a characteristic of Cu, and adhesion at the connection portion (interface) with a resistance layer, which is a characteristic of Ni, can be compatible. The effect that an electrode layer can be obtained is obtained.

  According to the fifth aspect of the present invention, in particular, the resistance layer is provided on the upper surface of the substrate, and the upper surface electrode layer is provided on the upper surface side of the resistance layer. It is configured to become thinner as it approaches the center side. According to this configuration, the step difference due to the upper surface electrode layer is reduced, so that the coverage of the upper surface electrode layer or the resistance layer by the protective layer is improved. As a result, the resistance layer can be prevented from being oxidized due to the intrusion of moisture from the protective layer, so that the effect of reducing the resistance value fluctuation can be obtained.

  According to the sixth aspect of the present invention, in particular, a resistance layer made of a metal material or a metal oxide material and an upper electrode layer made of a CuNi alloy are electrically connected to each other on the upper surface side of the substrate. Forming a protective layer so as to cover the resistance layer and the upper electrode layer, and forming the upper electrode layer using a thin film forming technique by sputtering or vacuum evaporation According to this manufacturing method, since the top electrode layer is formed using a thin film formation technique by sputtering or vacuum deposition, compared with a thick film formation technique formed by printing. A dense upper surface electrode layer can be formed, thereby improving the adhesion with the resistance layer and reducing the contact resistance between the resistance layer and the upper surface electrode layer. Use effect is obtained.

  In the invention according to claim 7 of the present invention, in particular, in the step of forming the upper electrode layer on the upper surface side of the substrate, the temperature of the substrate is 200 ° C. or higher, whichever is lower of the melting point of the resistance layer or the melting point of the upper electrode layer. According to this manufacturing method, Ni in the upper electrode layer diffuses into the resistance layer when the upper electrode layer is formed, and the contact resistance between the resistance layer and the upper electrode layer can be further reduced. Therefore, there can be obtained an effect that the resistance value fluctuation at the time of voltage load can be reduced.

  According to the eighth aspect of the present invention, in particular, a resistance layer made of a metal material or a metal oxide material and an upper electrode layer made of a CuNi alloy are electrically connected to each other on the upper surface side of the substrate. After the step of forming, the step of heat treatment at a temperature lower than the melting point of the resistance layer or the melting point of the upper electrode layer, which is 250 ° C. or higher, is added. Since the heat treatment is performed at a temperature lower than the melting point of the upper electrode layer or the melting point of the upper surface electrode layer, the resistance pattern of the resistance layer made of a metal material or a metal oxide material is stabilized by this heat treatment. The effect that it can be made into a film is obtained.

  As described above, the resistor of the present invention includes a substrate, a resistance layer and an upper electrode layer provided on the upper surface side of the substrate, and a protection covering the resistance layer and the upper electrode layer. And the resistance layer is made of a metal material or a metal oxide material, and the upper electrode layer is made of a CuNi alloy, so that Ni in the upper electrode layer diffuses into the resistance layer. As a result, a strong adhesion layer is formed between the upper surface electrode layer and the resistance layer, and the contact resistance can be further reduced, so that an excellent effect that resistance value fluctuation at the time of voltage load can be reduced can be achieved. It is.

(Embodiment 1)
Hereinafter, the first to fourth aspects of the present invention will be described with reference to the first embodiment.

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

In FIG. 1, reference numeral 11 denotes a substrate made of an insulating material such as alumina. Reference numeral 12 denotes a resistance layer made of a metal oxide material provided on the upper surface of the substrate 11. As the metal oxide material constituting the resistance layer 12, CrSiO, CrSiO ₂ , WSiO, WSiO ₂ or the like has resistance value stability. This is preferable. Reference numeral 13 denotes a pair of upper surface electrode layers made of a CuNi alloy provided on the upper surface of the substrate 11 so as to be electrically connected to the resistance layer 12 and located on the upper surface side of the resistance layer 12. Reference numeral 14 denotes a protective layer made of an inorganic material such as SiO ₂ or Al ₂ O ₃ provided so as to cover the resistance layer 12 and part of the upper electrode layer 13. Reference numeral 15 denotes a resin-based protective layer made of an epoxy resin or the like provided so as to cover at least the protective layer 14. Reference numeral 16 denotes an end face electrode layer provided from the back surface to the side face of the substrate 11, and this end face electrode layer 16 is electrically connected to at least the top face electrode layer 13, such as Cr-based, NiCr-based, CuNi-based, etc. It is comprised by the metal material. Reference numeral 17 denotes a nickel plating layer provided so as to cover the exposed portions of the end face electrode layer 16 and the upper face electrode layer 13. Reference numeral 18 denotes a solder plating layer or tin plating layer provided so as to cover the nickel plating layer 17.

  In the above configuration, the CuNi alloy constituting the upper electrode layer 13 has a total rate that Ni as an additive material is uniformly melted with Cu as a main element of the alloy thin film and metal elements such as Cr and W constituting the resistance layer 12. Since a solid solution is formed, Ni diffuses at the interface between the upper electrode layer 13 made of CuNi alloy and the resistance layer 12, thereby forming a strong adhesion layer at the interface. The adhesion of the electrode layer 13 can be improved.

  In the first embodiment of the present invention, the CuNi alloy used for the top electrode layer 13 is improved in adhesion with the resistance layer 12 if Ni is contained in Cu at least 1.6% by weight. If it is 1.6% by weight or more and 35% by weight or less, the wiring resistance can be reduced and good adhesion can be obtained, so that a stable resistor with a small fluctuation in resistance value can be obtained, which is even better. .

  Further, if the upper electrode layer 13 is formed by sputtering a Cu target and an Ni target separately, the upper electrode layer 13 is inclined so that the Ni content increases as it approaches the connection portion (interface) with the resistance layer 12. Since it becomes a composition, while being able to make wiring resistance still smaller, favorable adhesiveness can be obtained. In this case, if the Ni content in the upper electrode layer 13 is configured so that the vicinity of the connection portion with the resistance layer 12 is larger than the other portions, the above-described effects can be obtained.

  Further, the resistance layer 12 is most preferably composed of CrSiO. If the Cr content is 60% by weight or more and 90% by weight or less, the Cr atoms of the resistance layer 12 and the Ni atoms of the top electrode layer 13 are sufficiently strong. Since a good adhesion layer can be formed and the contact resistance can be reduced, a stable resistor with a small fluctuation in resistance value can be obtained, which is even better.

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

  FIG. 2 is a process diagram of the resistor in the first embodiment of the present invention. First, the board | substrate 11 containing the alumina excellent in heat resistance and insulation is received (process A).

  Next, the resistance layer 12 is formed on the entire surface of the substrate 11 by sputtering using a CrSiO target containing 75% by weight of Cr (step B).

  Next, in order to shape the resistance layer 12 into a predetermined resistance pattern shape, photoetching generally performed in a semiconductor is performed (step C).

  Next, using a metal target made of a CuNi alloy material containing 1.6% by weight of Ni, a resistance pattern 12 and an electrical layer are formed on the surface of the substrate 11 heated to 200 ° C. or higher by a heater or the like by sputtering. A pair of upper surface electrode layers 13 are formed so as to be connected to each other. The higher the temperature of the substrate 11, the more easily Ni diffuses, and this is preferable. However, if the temperature is higher than the melting point of the resistance layer 12 or the upper electrode layer 13, these melt and the predetermined shape cannot be obtained. Therefore, it is necessary to make it below these melting | fusing point (process D).

Next, a protective layer 14 made of an inorganic material such as SiO ₂ or Al ₂ O ₃ is formed by a sputtering method, a CVD method, or the like so as to cover a part of the resistance layer 12 and the upper electrode layer 13 (step E).

  Next, heat treatment is performed at a temperature of 250 ° C. or higher in vacuum or in the air in order to make the resistance pattern a stable film. A higher heat treatment temperature stabilizes the resistor pattern of the resistance layer 12 and is preferable in this respect. However, if the temperature is higher than the melting point of the resistance layer 12 or the upper surface electrode layer 13, they melt, so that the temperature is lower than the melting point. It is necessary to set the temperature (step F).

  Next, in order to correct the resistance value of the resistance layer 12 to a predetermined value, the resistance value is corrected by trimming with a YAG laser or the like (step G).

  Next, in order to protect the resistance layer 12 whose resistance value has been corrected, a resin paste made of an epoxy resin or the like is screen-printed, and then firmly adhered to the substrate 11 by a belt-type continuous curing furnace. The resin-based protective layer 15 is formed by thermosetting at about 30 ° C. for about 30 minutes (step H).

  Next, the end face electrode layer 16 made of a NiCr-based metal is formed by sputtering or the like so as to be electrically connected to the upper face electrode layer 13 from the back surface to the side surface of the substrate 11 (step I).

  Finally, in order to prevent electrode erosion during soldering, nickel plating is applied to the surfaces of the upper surface electrode layer 13 and the end surface electrode layer 16, and then solder plating or tin plating is performed. A layer or tin plating layer 18 is sequentially formed (step J).

  Through these manufacturing steps, the resistor in the first embodiment of the present invention is manufactured.

  Next, characteristics and the like of the resistor configured and manufactured as described above will be described.

  FIG. 3 shows the high temperature load life test (70 ° C., 1000 hours, 1.5 hours ON-0.5 hours OFF cycle for the resistor in the first embodiment of the present invention and the conventional resistor) It is the figure which showed the result of doing.

  In FIG. 3, the horizontal axis represents the test time, and the vertical axis represents the resistance value change rate. The white dots in FIG. 3 are the resistors in Embodiment 1 of the present invention, and the black dots are the conventional resistors. Is shown. Further, at each point, a straight line drawn in the vertical direction indicates variation in the resistance value tested.

  As can be seen from FIG. 3, the resistor according to the first embodiment of the present invention can reduce the fluctuation of the resistance value at the time of voltage load and reduce the variation as compared with the conventional resistor. did it.

  In the resistor according to the first embodiment of the present invention described above, the resistance layer 12 is made of CrSiO that is a metal oxide material, and the upper surface electrode layer 13 is made of a CuNi alloy. The Ni in the inside diffuses into the resistance layer 12, thereby forming a strong adhesion layer between the upper electrode layer 13 and the resistance layer 12, and the contact resistance can be further reduced. There is an effect that a stable resistor with small fluctuation in resistance value can be obtained.

  In the first embodiment of the present invention, the upper electrode layer 13 is configured to overlap the upper side of the resistance layer 12, but the upper electrode layer 13 is formed on the upper surface of the substrate 11, and this upper surface is formed. The resistive layer 12 may be superposed on the upper side of the electrode layer 13.

  In the first embodiment of the present invention, the resistance layer 12 is made of a metal oxide material made of a CrSiO thin film. However, the resistance layer 12 is made of a metal material such as a NiCr thin film or a CrSi thin film. Even when configured, since the Ni in the upper electrode layer 13 diffuses into the resistance layer 12, the same effect as in the first embodiment of the present invention can be obtained.

(Embodiment 2)
Hereinafter, the invention according to claim 5 of the present invention will be described using the second embodiment. FIG. 4 is a cross-sectional view of the resistor according to the second embodiment of the present invention. In the second embodiment of the present invention, the same components as those in the first embodiment of the present invention described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  The difference between the second embodiment of the present invention and the first embodiment of the present invention is that the shape of the upper electrode layer 13 is different. That is, the second embodiment of the present invention is different from the upper electrode layer 13 in that The thickness is configured to become thinner as it approaches the center side of the substrate 11.

With such a configuration, the level difference due to the upper surface electrode layer 13 is reduced, so that the coverage of the upper surface electrode layer 13 or the resistance layer 12 with the protective layer 14 is improved. Oxidation of the resistance layer 12 due to the intrusion of oxygen can be prevented, so that there are resistance value fluctuations due to the oxidation of the resistance layer 12 that are likely to occur during piezoelectric loading, and there are highly corrosive ions such as Na ⁺ , K ⁺ , and Cl ^−. It is also possible to suppress a disconnection failure mode due to electrolytic corrosion, which is likely to occur, and this has the effect of further reducing resistance value fluctuations at least during heat resistance, moisture resistance or voltage load.

  Further, in the second embodiment of the present invention, as in the first embodiment of the present invention described above, the Ni content in the upper surface electrode layer 13 is higher in the vicinity of the connection portion with the resistance layer 12 than in other portions. With this configuration, the high conductivity that is a characteristic of Cu and the adhesion at the connection portion (interface) with the resistance layer 12 that is a characteristic of Ni can be compatible. Thus, it is possible to obtain an upper surface electrode layer 13 that is stable.

  The resistor and the manufacturing method thereof according to the present invention can reduce the resistance value fluctuation at the time of voltage load, and are useful when applied to an electronic device or the like.

Sectional drawing of the resistor in Embodiment 1 of this invention Process diagram showing the manufacturing method The figure which shows the result of the high temperature load life test of the resistor in Embodiment 1 of this invention and the conventional resistor Sectional drawing of the resistor in Embodiment 2 of this invention Cross section of conventional resistor

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Board | substrate 12 Resistance layer 13 Upper surface electrode layer 14 Protective layer

Claims (8)

A substrate, a resistance layer and an upper electrode layer provided on the upper surface side of the substrate so as to be electrically connected to each other, and a protective layer covering the resistance layer and the upper electrode layer, the resistance layer being a metal material Or the resistor which comprised with the metal oxide material and comprised the said upper surface electrode layer with the CuNi alloy. The resistor according to claim 1, wherein the resistance layer is made of CrSiO which is a metal oxide material. The resistor according to claim 1, wherein the upper electrode layer is made of a CuNi alloy containing Ni in a proportion of 1.6 wt% to 35 wt% in Cu. The resistor according to claim 1, wherein the Ni content in the upper electrode layer is configured so that the vicinity of the connection portion with the resistance layer is larger than in other portions. The resistance layer is provided on the upper surface of the substrate, the upper surface electrode layer is provided on the upper surface side of the resistance layer, and the upper electrode layer is configured such that the thickness thereof becomes thinner as it approaches the central portion side of the substrate. Item 1. The resistor according to item 1. Forming a resistance layer made of a metal material or metal oxide material and a top electrode layer made of a CuNi alloy on the top surface of the substrate so as to be electrically connected to each other; and covering the resistance layer and the top electrode layer A step of forming a protective layer, and the step of forming the upper electrode layer is formed by using a thin film forming technique based on a sputtering method or a vacuum evaporation method. 7. The method of manufacturing a resistor according to claim 6, wherein in the step of forming the upper surface electrode layer on the upper surface side of the substrate, the temperature of the substrate is set to 200 ° C. or higher and lower than the melting point of the resistance layer or the melting point of the upper surface electrode layer. Method. After the step of forming the resistance layer made of a metal material or metal oxide material and the upper electrode layer made of CuNi alloy on the upper surface side of the substrate so as to be electrically connected to each other, The method for manufacturing a resistor according to claim 6, further comprising a step of performing heat treatment at a temperature lower than the lower one of the melting points of the upper electrode layer.

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