JP3763161B2 - Resistor and its manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resistor used in various electronic devices, and particularly to a resistor having a resistance film made of a copper-nickel alloy (Cu-Ni) having a low resistance and excellent resistance temperature characteristics, and a method of manufacturing the same. It is.
[0002]
[Prior art]
In recent years, with the improvement in performance and functionality of electronic devices, the demand for resistors having low resistance and excellent resistance temperature characteristics has been remarkably expanded.
[0003]
Conventionally, as a resistor having a low resistance and excellent temperature characteristics, a resistor film made of a Cu—Ni alloy has been widely used.
[0004]
The resistor film made of this Cu—Ni alloy is made by a method using both an electroless plating method and an electrolytic plating method. In the electroless plating method, divalent copper ions (Cu ²⁺ ) and divalent ions are used. Electroless plating solution using sodium citrate as a complexing agent and sodium hypophosphite as a reducing agent is most often used in a solution of nickel ions (Ni ²⁺ ). A low-resistance resistor has been made by forming a Cu—Ni alloy film on the surface of an insulating substrate such as an alumina substrate or an insulator that has been catalyzed using a liquid.
[0005]
[Problems to be solved by the invention]
However, a resistor film made of a Cu-Ni alloy deposited by such an electroless plating solution using sodium hypophosphite as a reducing agent, phosphorus (P) inevitably co-deposited in the film, Cu -Ni-P ternary alloy is formed, so that the electrical resistance value (sheet resistance value) of the resistance film is increased, and crystallization of Ni and P proceeds by heat treatment, so that the resistance temperature characteristic of the film (TCR) ) Was significantly worse.
[0006]
An object of the present invention is to provide a resistor having a low temperature resistance (sheet resistance value) of a resistance film and excellent temperature characteristics (TCR) with little resistance change due to heat treatment, and a method for manufacturing the same.
[0007]
[Means for Solving the Problems]
In order to solve this problem, the present invention is a complexing agent common to divalent copper ions (Cu ²⁺ ), divalent nickel ions (Ni ²⁺ ), and the respective metal ions, and Cu ²⁺ complexation capable, and Ni weak complexing agent having complexing capacity for ^2+, electroless plating solution which is based component and a reducing agent having a catalytic activity for the copper reduction precipitation with , A resistor film made of a Cu—Ni binary alloy film is provided on the surface of the insulating substrate, and external connection terminals are provided at a pair of opposite ends of the resistor film. As a result, a resistor having a low resistance film and an excellent resistance temperature characteristic can be obtained.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The invention of claim 1, wherein the present invention is a divalent of copper ions (Cu ²⁺⁾ and divalent nickel ion (Ni ^2+), wherein a common complexing agent of each metal ion, Cu ²⁺ complexation capable, and Ni weak complexing agent having complexing capacity for ^2+, electroless plating solution which is based component and a reducing agent having a catalytic activity for the copper reduction precipitation with A resistor film made of a Cu—Ni binary alloy film on the surface of an insulating substrate, and a pair of opposite ends of the resistor film provided with external connection terminals. Since the resistor is formed of a Cu—Ni binary alloy film that does not contain an impurity element such as (P), the resistor film has a low electrical resistance value (sheet resistance) and an excellent resistance temperature characteristic. can get.
[0009]
In the invention according to claim 2, a catalyst activation layer is provided on the surface of the insulating substrate, and a Cu—Ni binary alloy film is provided on the surface of the activation layer by the electroless plating solution according to claim 1, A resistor manufacturing method characterized in that an external connection terminal is provided at a pair of opposite ends of the resistor film, and a Cu-Ni binary alloy film is formed on the surface of an insulating substrate by an electroless plating solution. By forming the resistor, a resistor having a low electrical resistance value of the resistor film and excellent resistance temperature characteristics can be obtained.
[0010]
The invention according to claim 3 is provided with a catalyst activation layer on the surface of the insulating substrate, and a thin layer of Cu—Ni that becomes a base conductive film by the electroless plating solution according to claim 1 on the surface of the activation layer. Is a method of manufacturing a resistor, characterized in that a Cu-Ni alloy film is formed thickly by electroplating on the underlying conductive film, and external connection terminals are provided at both ends thereof. By forming a Cu-Ni alloy film having dense crystal particles by electroplating on a base conductive film made of a Cu-Ni binary alloy film, a resistor having excellent resistance temperature characteristics can be obtained. It is.
[0011]
The invention according to claim 4 is a resistor using an electroless plating solution using one of triethanolamine, glycerin, sorbitol or a derivative thereof as a complexing agent, and these complexing agents As a result, a resistor layer made of a high purity Cu—Ni binary alloy film is formed on the surface of the insulating substrate.
[0012]
The invention according to claim 5 is a resistor using one of formaldehyde or glyoxylic acid and derivatives thereof as a reducing agent. By using these reducing agents, the surface of the insulating substrate has high purity. A resistor layer made of a Cu—Ni binary alloy film is formed.
[0013]
The invention according to claim 6 is a method for manufacturing a resistor in which a Cu—Ni alloy film formed by electroless or electroplating is used in a reducing or inert atmosphere at a temperature range of 200 to 1000 ° C. This is a method in which a copper-nickel alloy film deposited by plating is heat-treated to reduce the stress of the film, remove occluded hydrogen gas, and further densify the crystal grains by grain growth, thereby reducing the resistance of the resistance film. And temperature characteristics are remarkably improved.
[0014]
Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG.
(Embodiment 1)
FIG. 1 is a sectional view of a chip resistor having a square shape as an example of a resistor according to the present invention.
[0015]
In FIG. 1, an insulating substrate 1 serves as a support for forming a resistor film 2 and is composed of an alumina substrate having a rectangular parallelepiped shape. The resistor film 2 is composed of a Cu—Ni binary alloy film as a film having low resistance and excellent temperature characteristics.
[0016]
The external connection terminals 3a and 3b are conductive metal layers that serve as terminals for electrically connecting the resistor to the printed wiring board, and the side wall surface and the back surface of the alumina substrate from a pair of opposite ends of the resistor film 2. A metal with excellent solderability, such as solder or tin, on the outermost layer, with a conductive metal layer made of Cu, Ni, or Cu-Ni alloy deposited over part of the surface and deposited by electroless plating or sputtering. It is composed of layers.
[0017]
The insulating resin 4 protects the resistor film and is made of a resin having excellent heat resistance and moisture resistance, such as an epoxy resin or a silicon resin.
[0018]
About the resistor comprised as mentioned above, the manufacturing method is demonstrated in detail below.
[0019]
Examples of the insulating substrate 1 that can be used in the present invention include a plate-like alumina substrate and a rod-like alumina insulator. First, the surface of the insulating substrate 1 is roughened by a chemical etching process for the purpose of improving the adhesion of plating. As the etching method, the surface was roughened by hydrofluoric acid or the surface was roughened by molten salt etching using sodium hydroxide.
[0020]
Next, a catalyst activation layer is applied to the insulating substrate 1 whose surface has been roughened. As an activation treatment method, it is possible to sequentially immerse in an acidic solution of stannous chloride and palladium chloride, or colloidal palladium. Activate the catalyst on the whole or part of the surface of the insulating substrate by immersing it in a liquid or kneading it into glass or a resin binder with fine particles of catalytically active metal such as palladium and applying it by screen printing or spraying. A layer (not shown) was formed.
[0021]
Thereafter, it was immersed in an electroless plating solution to form a Cu—Ni alloy film 2 on the entire surface or a part of the surface of the insulating substrate.
[0022]
In this case, the electroless plating solution contains divalent copper ions (Cu ²⁺ ) and divalent nickel ions (Ni ²⁺ ), and has a complex forming ability with Cu ²⁺ as a complexing agent. Insulating substrate 1 using a plating solution using a complexing agent having a relatively weak ability to form a complex with Ni ²⁺ and a reducing agent mixed with a reducing agent having catalytic activity for copper reduction precipitation. A Cu—Ni alloy film 2 was deposited on the surface of the film so that a desired sheet resistance value was obtained.
[0023]
As a complexing agent for the electroless plating solution, triethanolamine, glycerin, sorbitol, or one of their derivatives was used. As the reducing agent, formaldehyde, glyoxylic acid or one of their derivatives used in general electroless copper plating was used. An example of the composition of the electroless plating solution used in the first embodiment is shown below.
[0024]
Copper sulfate (Cu ²⁺ ) ………………………… 0.002-0.02 mol / l
Nickel sulfate (Ni ²⁺ ) …………………… 0.1 mol / l
Triethanolamine (complexing agent) ………… 0.2mol / l
Formaldehyde (reducing agent) ……………… 0.06mol / l
pH (adjusted with NaOH) ……………… 13
Using this electroless plating solution, the temperature of the solution is adjusted to a range of 30 ° C., and an insulating substrate 1 made of an alumina substrate subjected to activation treatment is dipped, so that Cu is 50 to 70 wt% and Ni is 30 to 30%. A Cu—Ni alloy film 2 having a composition ratio of 50 wt% was deposited.
[0025]
And what formed the resistor film 2 which consists of a binary alloy of Cu-Ni on the surface of the insulating base | substrate 1 with such an electroless-plating liquid WHEREIN: Forming external connection terminals 3a and 3b made of, for example, copper, nickel, silver, or an alloy thereof by electroless plating, sputtering, or conductive resin over a part of the side wall and further back of the conductive substrate; Thereafter, the resistor film 2 is trimmed to a predetermined resistance value using a YAG laser, and finally the resistor film 2 is coated with an insulating resin 4 such as an epoxy resin or a silicon resin to reduce the resistance film 2 Resistor chip resistors were fabricated.
[0026]
The resistor obtained by such a method is composed of a high-purity Cu-Ni binary alloy in which the impurity element contained in the reducing agent of the electroless plating solution is not co-deposited in the resistor film. A resistor having low electric resistance of the film and excellent resistance temperature characteristics can be obtained.
[0027]
The Cu—Ni alloy film obtained by electroless plating is thinly formed on an insulating substrate as a Cu—Ni base conductive film by electroplating, and then electroplated with pyrophosphoric acid solution or citric acid solution. The resistor film may be formed by thickening the Cu—Ni binary alloy film.
[0028]
Furthermore, a resistor film is obtained by heat-treating a Cu—Ni alloy film obtained in combination with electroless plating or electroplating in a temperature range of 200 to 1000 ° C. in a mixed gas of hydrogen and nitrogen or in a nitrogen gas atmosphere. It was confirmed that the electrical resistance value and resistance temperature characteristics of the resistor film were further improved by relaxation of internal stress, removal of occluded hydrogen gas, and grain growth of precipitated crystal particles.
[0029]
In the above description, the rectangular chip resistor in which the resistor film 2 made of a Cu—Ni alloy is formed by electroless plating on a plate-like alumina substrate having a rectangular parallelepiped as the insulating substrate 1 has been described. The insulating substrate on which the resistance film is formed is not limited to a plate-like alumina substrate, a Cu-Ni alloy film is formed on the surface of a rod-like alumina insulator, and metal caps with lead wires are press-fitted at both ends. It can also be implemented for round resistors.
[0030]
【The invention's effect】
As described above, according to the present invention, there is provided a resistor in which a resistor film made of a Cu—Ni binary alloy is formed on the surface of an insulating substrate by electroless plating.
[0031]
In the present invention, sodium hypophosphite is not used as a reducing agent, and an element such as formaldehyde and glyoxylic acid that does not have an adverse effect on the resistor film is used. By forming a high-purity Cu—Ni binary alloy film that does not contain, the electrical resistance value can be lowered and the resistance temperature characteristic can be improved.
In the present invention, the complexing agent is common to divalent copper ions (Cu ²⁺ ) and divalent nickel ions (Ni ²⁺ ), has a complex forming ability with Cu ²⁺ , and Using Ni ²⁺ with a weak complex-forming ability and using a reducing agent that has catalytic activity for copper reduction precipitation further lowers the electrical resistance and increases resistance temperature characteristics. be able to.
[0032]
Therefore, as the electrical characteristics of the resistor film, the electrical resistance value is particularly low, and the resistance temperature characteristics (TCR) are remarkably improved from ± 300 to 500 ppm / ° C. of the conventional example to ± 50 ppm / ° C.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a resistor according to an embodiment of the present invention.
1 Insulating substrate 2 Resistor film (Cu-Ni alloy film)
3a, 3b External connection terminal 4 Insulating resin

Claims (6)

Divalent copper ion (Cu ²⁺ ), divalent nickel ion (Ni ²⁺ ), and a common complexing agent for each of the above metal ions , having the ability to form a complex with Cu ²⁺ , and Ni weak and a complexing agent having complexing capacity for ^2+, and a reducing agent having a catalytic activity using an electroless plating solution which is based components to copper reduction precipitation, copper on the surface of an insulating substrate A resistor in which a resistor film made of a nickel (Cu-Ni) binary alloy layer is provided, and external connection terminals are provided at a pair of opposite ends of the resistor film.   A catalyst activation layer is selectively provided on the surface of the insulating substrate, and a resistor film comprising a copper-nickel binary alloy film is provided on the surface of the activation layer by the electroless plating solution according to claim 1, A method of manufacturing a resistor, characterized in that external connection terminals are provided at both ends of the resistor film.   A catalyst activation layer is provided on the surface of the insulating substrate, and a thin layer of copper-nickel binary alloy film to be a base conductive film is provided on the surface of the activation layer by the electroless plating solution according to claim 1. A resistor film made of a copper-nickel binary alloy film is formed on a conductive film by electroplating, and an external connection terminal is provided at a pair of opposite ends of the resistor film. Method.   The resistor according to claim 1, wherein one of triethanolamine, glycerin, sorbitol, or a derivative thereof is used as the complexing agent.   The resistor according to claim 1, wherein formaldehyde or glyoxylic acid and one of derivatives thereof are used as the reducing agent.   3. A Cu—Ni binary alloy film formed by using electroless plating or electroplating in combination is subjected to heat treatment at a temperature range of 200 to 1000 ° C. in a reducing or inert atmosphere. 3. A method for producing a resistor according to 3.

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