JP2004056001A - Thick film low resistance resistor and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thick film low resistance resistor having low resistance temperature coefficient characteristics with a low resistance. <P>SOLUTION: A thick film lower face internal electrode layer 12 is formed at the both ends of the lower face of an insulating film 11. A thick film resistor layer 13 having low resistance temperature coefficient characteristics with a low resistance is formed on the upper face of the insulating substrate 11. A thick film upper internal electrode layer 14 having low resistance temperature coefficient characteristics with a low resistance is formed so as to be laminated on the both ends of the thick film resistor layer 13. An end face internal electrode layer 17 is formed on the both end faces of the insulating substrate 11 so as to be connected to the thick film upper face internal electrode layer 14 and the thick film lower face internal electrode layer 12. A first protecting coat 15 is formed on the surface of the thick film resistor film 13. A resin protecting coat 16 is formed on the surface of the first protecting coat 15 as necessary. An end face internal electrode layer 17 is formed on the both end faces of the insulating film 11. An external electrode layer 18 is formed on the external surfaces of the thick film lower face internal electrode layer 12, the thick film upper face internal electrode layer 14, and the end face internal electrode layer 17. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to a thick-film low-resistance chip resistor such as a thick-film low-resistance chip resistor having a low-resistance and low-resistance temperature coefficient characteristic used as a surface-mount component of an electronic circuit in an electronic device such as a small communication device, a computer, and an information device. The present invention relates to a resistor and a method for manufacturing the resistor.
[0002]
[Prior art]
Conventionally, as shown in FIG. 3, a thick-film low-resistance chip resistor of this type forms a thick-film lower-surface internal electrode layer 2 by printing and baking paste containing copper powder on both lower ends of a ceramic insulating substrate 1. Then, paste containing copper powder is printed and baked on both ends of the upper surface of the insulating substrate 1 to form the thick film upper surface internal electrode layer 3, and both ends are connected to the thick film upper surface internal electrode layer 3 to form the insulating film. The thick film resistor layer 4 is formed by printing and firing a paste containing copper nickel powder on the substrate 1, and the glass coat layer 5 is formed by printing and firing a glass paste on the surface of the thick film resistor layer 4. Further, a resin paste is printed and cured on the surface of the glass coat layer 5 to form a protective coat layer 6, and the end face internal electrode layer 7 made of a nickel-chromium alloy is formed on both end faces of the insulating substrate 1 by vacuum evaporation or sputtering. Form each A thick film end surface electrode layer 8 in which a nickel plating layer and a solder plating layer are laminated on the both end surface internal electrode layer 7, the thick film upper surface internal electrode layer 3, and the thick film lower surface internal electrode layer 2 is formed. Had been taken.
[0003]
The thick film upper surface internal electrode layer 3 is formed using the conventional copper paste shown in FIG. 3, and the paste containing copper nickel powder is printed and fired to form the thick film resistor layer 4 of copper nickel alloy. The resistance chip resistor has a problem that the temperature coefficient of resistance increases as the resistance value decreases.
[0004]
In the thick-film low-resistance chip resistor described in Japanese Patent Application Laid-Open No. 10-144501, a paste containing copper nickel powder is printed and fired on the upper surface of an insulating substrate to form a thick-film resistor layer. A configuration is adopted in which pastes containing copper or silver are printed and baked on both ends of the thick-film resistor layer, and the thick-film upper-surface internal electrode layers are formed in a laminated manner.
[0005]
In the thick-film low-resistance chip resistor described in Japanese Patent Application Laid-Open No. H10-144501, although the improvement is made as compared with the thick-film low-resistance chip resistor shown in FIG. 3, the lower the resistance value, the higher the temperature coefficient of resistance. There was a problem that a good characteristic could not be obtained.
[0006]
[Problems to be solved by the invention]
In the conventional thick-film low-resistance chip resistor shown in FIG. 3 and the thick-film low-resistance chip resistor described in JP-A-10-144501, the lower the resistance value, the higher the temperature coefficient of resistance. Cannot be ignored in a region where the resistance value is approximately 200 mΩ or less. This is due to the temperature coefficient of resistance of the electrode portion occupying the current path of the resistor.
[0007]
The portion occupying a large proportion in the material, area, and the like of the electrode portion is the upper surface internal electrode, and the copper or silver-based thick film electrode layer used in the conventional technology has a temperature coefficient of resistance of 2000 ppm / ° C. to 4000 ppm / ° C. There are major causes.
[0008]
The present invention has been made in view of the above problems, and provides a thick film low resistance resistor having low resistance and low resistance temperature coefficient characteristics, and a method for manufacturing the same.
[0009]
[Means for Solving the Problems]
2. A thick-film low-resistance resistor according to claim 1, wherein said thick-film resistor layer has a low-resistance and low-resistance temperature coefficient characteristic formed on an upper surface of said insulating substrate. And a thick film upper surface internal electrode layer having a low resistance and a low temperature coefficient of resistance, respectively, which is formed by lamination at both ends of the thin film.
[0010]
Then, the thick film upper internal electrode layer laminated on the thick film resistor layer has a low resistance temperature coefficient, and a thick film low resistance resistor having a low resistance and a low resistance temperature coefficient can be obtained.
[0011]
A thick-film low-resistance resistor according to claim 2, wherein the insulating substrate, a thick-film lower-surface internal electrode layer formed on both ends of the lower surface of the insulating substrate, and a low-resistance and low-resistance formed on the upper surface of the insulating substrate. A thick-film resistor layer having a temperature coefficient of resistance characteristic; a thick-film upper-surface internal electrode layer laminated and formed on both ends of the thick-film resistor layer to have a low-resistance and low-resistance temperature-coefficient characteristic; At least an end face internal electrode layer formed on both end faces of the insulating substrate connected to the internal electrode layer and the thick film lower face internal electrode layer.
[0012]
Then, the thick film upper surface internal electrode layer laminated on the thick film resistor layer has a low temperature coefficient of resistance, and a thick film low resistance resistor having a low resistance and a low resistance temperature coefficient as the whole resistor can be obtained.
[0013]
A thick film low resistance resistor according to claim 3 is the thick film low resistance resistor according to claim 1 or 2, wherein the thick film resistor layer and the thick film upper internal electrode layer are copper nickel thick film layers.
[0014]
A thick film low resistance resistor according to claim 4 is the thick film low resistance resistor according to claim 1 or 2, wherein the thick film resistor layer is a copper nickel thick film layer, and the thick film upper surface internal electrode layer is silver. It is a palladium thick film layer.
[0015]
The thick film low resistance resistor according to claim 5 is the thick film low resistance resistor according to any one of claims 1 to 4, wherein the thick film resistor layer includes 80 to 30 parts by mass of copper and 20 to 70 parts by mass of nickel. Thick film resistor element of a mixture of individual parts of mass or alloy powder of copper and nickel, and metal oxide of 1 to 10 parts by mass with respect to 100 parts by mass of the whole thick film resistor element, It contains at least 1 to 10 parts by mass of glass with respect to 100 parts by mass of the entire thick film resistor element.
[0016]
Then, a compound having a spinel structure is generated between the substrate and the thick-film resistor layer by the metal oxide contained in the thick-film resistor layer, and strong adhesion between the substrate and the thick-film resistor layer is obtained. Does not occur, and the thick film resistor layer does not peel off from the substrate.
[0017]
A method of manufacturing a thick-film low-resistance resistor according to claim 6, wherein a thick-film paste containing copper-nickel powder is printed and fired on the upper surface of the insulating substrate to form a thick-film resistor layer of copper-nickel alloy; Printing and baking a thick film paste containing copper nickel powder on both ends of the thick film resistor layer to form a thick film upper surface internal electrode layer of copper nickel alloy on the thick film resistor layer at least. It is provided.
[0018]
Then, the internal electrode layer formed by laminating the thick film resistor layer by printing and firing the thick film paste has a low resistance temperature coefficient, and a thick film low resistance resistor having a low resistance and a low resistance temperature coefficient can be obtained.
[0019]
8. A method of manufacturing a thick-film low-resistance resistor according to claim 7, wherein a thick-film lower-surface internal electrode layer is formed on both ends of a lower surface of the insulating substrate, and a thick-film paste containing copper-nickel powder on the upper surface of the insulating substrate. Forming a thick film resistor layer of a copper-nickel alloy by printing and firing, and printing and firing a thick film paste containing copper nickel powder on both ends of the thick film resistor layer, respectively. Forming a thick film upper surface internal electrode layer of a copper-nickel alloy on the layer, and connecting the end surface internal electrode layers connected to the thick film upper surface internal electrode layer and the thick film lower surface internal electrode layer to both end surfaces of the insulating substrate. And at least a forming step.
[0020]
Then, the internal electrode layer formed by laminating the thick film resistor layer by printing and baking the thick film paste has a low resistance temperature coefficient, so that a thick film low resistance resistor having a low resistance and a low resistance temperature coefficient can be obtained as a whole resistor. .
[0021]
A method of manufacturing a thick-film low-resistance resistor according to claim 8, wherein a thick-film paste containing copper-nickel powder is printed and fired on the upper surface of the insulating substrate to form a thick-film resistor layer of a copper-nickel alloy. Printing and baking a thick film paste containing silver palladium powder on both ends of the thick film resistor layer to form a thick film upper surface internal electrode layer of a silver-palladium alloy on the thick film resistor layer. It has at least.
[0022]
Then, the internal electrode layer formed by laminating the thick film resistor layer by printing and firing the thick film paste has a low resistance temperature coefficient, and a thick film low resistance resistor having a low resistance and a low resistance temperature coefficient can be obtained.
[0023]
10. The method of manufacturing a thick film low resistance resistor according to claim 9, wherein a thick film lower surface internal electrode layer is formed on both ends of a lower surface of the insulating substrate, and a thick film paste containing copper nickel powder on the upper surface of the insulating substrate. Forming a thick film resistor layer of a copper-nickel alloy by printing and firing, and printing and firing a thick film paste containing silver palladium powder on both ends of the thick film resistor layer, respectively. Forming a thick film upper surface internal electrode layer of a silver-palladium alloy on the body layer; and connecting the end surface internal electrode layers connected to the thick film upper surface internal electrode layer and the thick film lower surface internal electrode layer to both end surfaces of the insulating substrate. And at least a step of forming the same.
[0024]
Then, the internal electrode layer formed by laminating the thick film resistor layer by printing and baking the thick film paste has a low resistance temperature coefficient, so that a thick film low resistance resistor having a low resistance and a low resistance temperature coefficient can be obtained as a whole resistor. .
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the thick film low resistance chip resistor in the thick film low resistance resistor according to the present invention will be described with reference to the drawings.
[0026]
In FIG. 1, the insulating substrate 11 is formed of a ceramic of 96% alumina, for example, in a rectangular shape having a length of about 3.2 mm and a width of about 1.6 mm.
[0027]
A copper thick film paste containing copper powder is printed, dried, and fired on both ends of the lower surface of the insulating substrate 11 to form a copper (Cu) thick film lower surface internal electrode layer 12.
[0028]
Further, a thick film paste containing a mixed powder or an alloy powder of a metal having low resistance and a low resistance temperature coefficient characteristic, for example, a copper-nickel powder is printed and fired on the upper surface of the insulating substrate 11 to reduce the temperature. A thick-film resistor layer 13 made of a copper-nickel (CuNi) alloy having resistance and low resistance temperature coefficient characteristics is formed. The thick-film resistor element of the thick-film paste forming the thick-film resistor layer 13 having the low-resistance and the low-resistance temperature coefficient characteristic is, for example, 80 to 30, preferably about 60 parts by mass of copper in mass ratio, Nickel may be used in the form of a mixture powder of 20 to 80 parts by mass, preferably about 40 parts by mass, or a copper-nickel powder composed of an alloy powder. It is alloyed in later firing.
[0029]
The thick-film resistor element of the thick-film paste contains 1 to 10 parts by mass, preferably about 5 parts by mass of a metal oxide such as copper oxide (Cu （or Cu) in the entire thick-film resistor element. ₂ I) 1 to 10 parts by weight, preferably about 5 parts by weight, of glass and powder, for example, lead borosilicate (PbBSiO _X System) glass and 7 to 17 parts by weight, preferably about 12 parts by weight, of a vehicle, such as an organic vehicle, of the entire thick film resistor element.
[0030]
The organic vehicle contains, for example, ethyl cellulose, butyl carbitol, and the like.
[0031]
A thick-film upper surface internal electrode layer 14 having a low resistance and a low temperature coefficient of resistance is formed by being laminated on both ends of the thick-film resistor layer 13, respectively. The thick film upper internal electrode layer 14 is made of the same material as the thick film resistor layer 13, and the thick film paste for forming the thick film upper internal electrode layer 14 having low resistance and low temperature coefficient of resistance is copper nickel Powder, copper oxide (CuО or Cu ₂ О) Lead borosilicate (PbBSiO) as powder and glass frit _X System) glass, to which an organic vehicle is mixed.
[0032]
The thicknesses of the thick-film resistor layer 13 and the thick-film upper internal electrode layer 14 are each about 20 to 40 micrometers, and the sintered particle diameter is about several micrometers in surface observation.
[0033]
Further, the particle diameter of the copper powder is 0.1 μm to 5 μm, and the particle diameter of the nickel powder is 0.1 μm to 5 μm, and preferably both the copper powder and the nickel powder have the average particle diameter. Is in the range of 0.5 μm to 1 μm.
[0034]
Further, as the glass frit, zinc borosilicate, lead borosilicate glass having a softening point of 500 ° C. to 800 ° C. is suitable.
[0035]
A first protective coat 15 is formed on the surface of the thick film resistor layer 13. The first protective coat 15 may be a resin (for example, an epoxy resin (150 ° C. to 250 ° C., preferably 200 ° C. for 30 minutes)) and a glass (for example, 550 ° C. to 750 ° C., preferably 650 ° C. for 10 minutes). ). However, in the case of the resin, the first protective coat 15 is formed after the thick film resistor layer 13 is trimmed, whereas in the case of the glass, the first protective coat 15 is formed on at least the thick film resistor layer 13. Is trimmed after forming.
[0036]
Further, if necessary, one or more resin protective coats 16 may be formed by printing and curing a resin paste such as an epoxy resin on the surface of the first protective coat 15.
[0037]
On both end faces of the insulating substrate 11, end face internal electrode layers 17 are formed to be connected to the thick film upper internal electrode layer 14 and the thick film lower internal electrode layer 12, respectively. The end face internal electrode layer 17 is formed of a nickel chromium alloy thin film by sputtering or vacuum evaporation.
[0038]
Further, a nickel plating layer, a copper thick film plating layer (about 20 μm), a nickel plating layer, and a tin plating layer (approximately 20 μm) are formed on the outer surfaces of the thick film lower surface internal electrode layer 12, the thick film upper surface internal electrode layer 14, and the end surface internal electrode layer 17. Alternatively, an external electrode layer 18 formed by laminating solder plating layers) is formed.
[0039]
The operation of this embodiment will be described.
[0040]
A thick-film lower-surface internal electrode layer 12 is formed at both ends of a lower surface of the insulating substrate 11, and a thick-film resistor layer 13 of a copper-nickel alloy is formed on the upper surface of the insulating substrate 11. A thick-film upper internal electrode layer 14 of copper-nickel alloy is formed on each portion, and the thick-film upper internal electrode layer 14 and the thick-film lower internal electrode layer 12 are connected to each other. In the thick-film low-resistance resistor in which the thin-film end surface internal electrode layer 17 is formed, the resistance temperature coefficient of the thick-film resistor layer 13 and that of the thick-film upper internal electrode layer 14 are the same, and the resistance is increased by the thick-film upper internal electrode layer 14. The temperature coefficient does not increase, and has a low resistance and a low resistance temperature coefficient characteristic of 100 ppm / ° C. or less.
[0041]
That is, in this configuration, the copper-nickel alloy thick film upper surface internal electrode layer 14 can provide a low-resistance temperature coefficient characteristic that is 1/20 to 1/40 or less of that of the copper thick film upper surface internal electrode layer.
[0042]
Also, since the thick-film resistor layer contains 1 to 10 parts by mass of a metal oxide, for example, copper oxide, of the entire thick-film resistor element containing copper and nickel, the insulating substrate 11, for example, in the case of alumina ceramic, a compound having a spinel structure is generated between copper oxide and aluminum oxide, and strong adhesion occurs between the insulating substrate 11 and the thick-film resistor layer 13; The thick film resistor layer does not peel off from the substrate.
[0043]
The metal oxide contained in the thick film resistor element is copper oxide (CuО or Cu ₂ The present invention is not limited to О), and various metal oxides capable of producing a spinel structure or other relatively strong structures with the component materials of the insulating substrate 11 can be used. For example, as a material forming a spinel structure with the alumina substrate in this embodiment, copper oxide (CuО or Cu ₂ In addition to О), monovalent or divalent metal oxides such as nickel oxide (NiО), zinc oxide (ZnО), and magnesium oxide (MgО) may be used. However, in this embodiment, since the thick film resistor element is a paste made of a mixed powder of copper and nickel or an alloy powder, copper oxide (CuО or Cu ₂ Other than the method (ii), for example, nickel oxide (Ni) is preferable.
[0044]
In this embodiment, by forming the thick film upper surface internal electrode layer 14 in two or more layers, it is possible to suppress an increase in the resistance value of the electrode portion.
[0045]
The thick-film resistor layer 13 and the thick-film upper-surface internal electrode layer 14 are formed of the same material thick-film paste and have the same resistance value. By increasing the resistance value, the resistance value can be slightly lowered, and the balance between the resistance value and the low resistance temperature coefficient can be adjusted.
[0046]
In the above-described embodiment, the thick-film upper-layer internal electrode layers 14 made of the copper-nickel alloy are formed on both ends of the thick-film resistor layer 13 made of the copper-nickel alloy, respectively. The thick film resistor layer 13 is made of a copper-nickel alloy thick film by a thick film paste, and the thick film upper surface internal electrode layer 14 is made of a silver palladium (AgPd) alloy thick film layer by a thick film paste containing silver palladium powder. You can also. The silver palladium powder of the thick film paste material can be either an alloy powder or a mixed powder, and in the case of a mixed powder, is alloyed by firing after printing.
[0047]
In the thick-film low-resistance chip resistor in which the thick-film upper-surface internal electrode layer 14 according to this embodiment is formed of a silver-palladium (AgPd) alloy thick-film layer, the thick-film resistor layer 13 and the thick-film upper-surface internal electrode layer 14 are formed. The resistance temperature coefficient is substantially the same, the increase in the resistance temperature coefficient is suppressed by the thick film upper surface internal electrode layer 14, and the low resistance has a low resistance temperature coefficient characteristic of 100 ppm / ° C. or less.
[0048]
That is, in this configuration, the silver-palladium alloy thick film upper surface internal electrode layer 14 provides a lower resistance temperature coefficient characteristic than the copper thick film upper surface internal electrode layer.
[0049]
Also in this embodiment, by forming the thick film upper surface internal electrode layer 14 in two or more layers, it is possible to suppress an increase in the resistance value of the electrode portion.
[0050]
Next, an embodiment of a method of manufacturing a thick-film low-resistance chip resistor will be described with reference to FIGS.
[0051]
In the first step, a ceramic insulating plate having a dividing groove of 96% of alumina (not shown) is provided on the insulating substrate 11 in each region surrounded by the dividing grooves formed in the vertical and horizontal directions. A thick film paste containing a copper powder is printed at both ends of the lower surface of the insulating substrate 11 so as to straddle the groove, dried, and baked at 800 ° C. to 1000 ° C., preferably 900 ° C. for 10 minutes in a nitrogen atmosphere. As a result, the thick film lower surface internal electrode layers 12 are formed at both ends of the lower surface of the insulating substrate 11, respectively. Note that the atmosphere is not limited to an inert (or neutral) atmosphere such as nitrogen, but may be an inert (or neutral) atmosphere such as argon.
[0052]
In the second step, a thick film paste containing copper-nickel powder is printed on the upper surface of each of the insulating substrates 11 (not shown) of the insulating base plate, dried, and dried at 800 ° C. to 1000 ° C. in a nitrogen atmosphere. By baking at 900 ° C. for 10 minutes, the thick-film resistor layers 13 of the copper-nickel alloy are formed.
[0053]
The third step is to print a thick film paste containing copper nickel powder on both ends of the upper surface of the thick film resistor layer 13, and then dry and print the film at 800 ° C. to 1000 ° C., preferably 900 ° C. in a nitrogen atmosphere. By baking for 10 minutes, a thick-film upper surface internal electrode layer 14 of a copper-nickel alloy is laminated on the thick-film resistor layer 13.
[0054]
In a fourth step, a first protective paste is printed on the surface of the thick film resistor layer 13, dried, and heat-treated in a nitrogen atmosphere to form a first protective coat 15.
[0055]
In the fifth step, the first protective coat 15 and the thick film resistor layer 13 are trimmed by a laser or the like, and the resistance value of the thick film resistor layer 13 is adjusted.
[0056]
In the sixth step, a resin paste such as an epoxy resin is printed on the surface of the first protective coat 15 and cured by heating at 150 ° C. to 250 ° C., preferably 200 ° C. for 30 minutes in the atmosphere. A coat 16 is formed.
[0057]
In a seventh step, the insulating element plate (not shown) is cut along a notch (not shown) to form a strip-shaped insulating element plate (first substrate division). A thick film resistor layer 13, a thick film upper internal electrode layer 14, a first protective coat 15 and a resin protective coat 16 are formed in the longitudinal direction on the upper surface of this strip-shaped insulating element plate, and the thick film lower surface is formed on both lower surfaces. Resistor elements having the internal electrode layers 12 are formed at predetermined intervals.
[0058]
In an eighth step, an end face internal electrode layer 17 connecting the thick film lower face internal electrode layer 12 and the thick film lower face internal electrode layer 12 of the resistor body (not shown) is positioned on both end faces of the divided insulating substrate. Formed on the end face. For example, a nickel chromium alloy thin film is formed on the end face internal electrode layer 17 by vacuum evaporation or sputtering.
[0059]
In the ninth step, the resistor element (not shown) is formed into a strip having the thick-film resistor layer 13, the thick-film upper internal electrode layer 14, the first protective coat 15, the resin protective coat 16, and the end-face internal electrode layer 17 formed thereon. The resistor element body is cut from between the strip-shaped insulating substrates 11 along the adjacent substrate dividing groove of the resistor element body in a rectangular shape, for example, to have a rectangular insulation of about 3.2 mm in length and 1.6 mm in width, respectively. A substrate 11 is obtained.
[0060]
The tenth step is to form a nickel plating layer, a copper thick film plating layer (about 20 μm), a nickel plating layer on the outer surfaces of the thick film upper internal electrode layer 14, the end face internal electrode layer stack 17 and the lower internal electrode layer 15; The external electrode layer 18 formed by laminating tin plating (or solder plating layer) is formed.
[0061]
Through the first to tenth steps, the thick-film lower-surface internal electrode layers 12 are formed at both ends of the lower surface of the insulating substrate 11, and the thick-film resistor layer 13 of copper-nickel alloy is formed on the upper surface of the insulating substrate 11. On both ends of the thick-film resistor layer 13, a thick-film upper-surface internal electrode layer 14 of a copper-nickel alloy is formed by lamination, and further, the first protective coat 15 or, if necessary, The thick film upper surface internal electrode layer 14 and the thick film lower surface internal electrode layer 12 are connected to each other to form a resin protective coat 16 on the end surface of the nickel chrome alloy thin film on both end surfaces of the insulating substrate 11. A thick-film low-resistance resistor having the electrode layer 18 formed thereon is efficiently formed.
[0062]
Next, another embodiment of the method of manufacturing the thick film low resistance resistor will be described.
[0063]
The first step and the second step are the same as the method shown in FIG.
[0064]
In the third step, a thick film paste containing silver palladium powder is printed on both ends of the thick film resistor layer 13 and baked at 750 ° C. to 950 ° C., preferably 850 ° C. for 10 minutes in a nitrogen atmosphere. By doing so, a thick film upper surface internal electrode layer 14 of a silver-palladium alloy is laminated on the thick film resistor layer 13.
[0065]
The fourth to tenth steps are the same as the method shown in FIG.
[0066]
Also in this embodiment, the thick-film lower-surface internal electrode layers 12 are formed at both ends of the lower surface of the insulating substrate 11 by the first to tenth steps, and the thick-film resistor layer of copper-nickel alloy is formed on the upper surface of the insulating substrate 11. 13, a thick-film upper electrode layer 14 of silver-palladium alloy is formed on both ends of the thick-film resistor layer 13, and a first protective coat 15 is formed on the thick-film resistor layer 13. Alternatively, a resin protective coat 16 is laminated and formed, and the thick film upper surface internal electrode layer 14 and the thick film lower surface internal electrode layer 12 are connected to each other to form an end surface internal electrode layer 17 of a nickel chromium alloy thin film on both end surfaces of the insulating substrate 11. A thick film low resistance resistor having an external electrode layer 18 formed by laminating four layers of a nickel plating layer, a copper thick film plating layer (about 20 μm), a nickel plating layer, and a tin plating layer (or a solder plating layer) is formed efficiently. Is .
[0067]
Also in this embodiment, by forming the thick film upper surface internal electrode layer 14 in two or more layers, it is possible to suppress an increase in the resistance value of the electrode portion.
[0068]
The internal electrode layer on the upper surface of the thick film of silver-palladium alloy has a low resistance temperature coefficient characteristic that is 1/20 to 1/40 or less of that of the thick film (upper surface internal) electrode layer (not each of them alone). Is obtained.
[0069]
Further, in the embodiment of the method of manufacturing the thick-film low-resistance resistor, a thick-film paste containing copper nickel powder is printed on both ends of the thick-film resistor layer 13 in the third step. Baking in a nitrogen atmosphere at 800 ° C. to 1000 ° C., preferably 900 ° C. for 10 minutes to form a thick upper surface internal electrode layer 14 of copper-nickel alloy on the thick film resistor layer 13, or A thick film paste containing silver palladium powder is printed on both ends of the film resistor layer 13 and baked in a nitrogen atmosphere at 750 ° C. to 950 ° C., preferably 850 ° C., for 10 minutes to obtain a thick film resistor. The step of laminating and forming the thick-film upper internal electrode layer 14 of the silver-palladium alloy on the body layer 13 is repeated a plurality of times to form the thick-film upper internal electrode layer 14 in a plurality of layers, thereby making it possible to reduce the resistance of the electrode portion. It is possible to suppress that the value is increased.
[0070]
【Example】
As a comparative example, measurement was made by comparing the thick-film low-resistance chip resistor shown in FIG. 3 with the embodiment of the present invention shown in FIG.
[0071]
Comparative Example 1
On a rectangular insulating substrate 1 having a length of about 3.2 mm and a width of about 1.6 mm, a thick film upper surface internal electrode layer made of copper paste having a sheet resistance of 2 mΩ / □, a film thickness of 15 μm, and a temperature coefficient of resistance of +3500 ppm / ° C. 3 and a thick-film low-resistance chip resistor in which a thick-film resistor layer 4 is formed from a paste containing copper-nickel powder having a sheet resistance of 30 mΩ / □, a film thickness of 15 μm, and a temperature coefficient of resistance of +50 ppm / ° C. The resistance value was 41.1 mΩ and the temperature coefficient of resistance was +229 ppm / ° C. (average value).
[0072]
Comparative Example 2
A thick-film upper internal electrode layer 3 is formed on a rectangular insulating substrate 1 having a length of about 3.2 mm and a width of about 1.6 mm with a copper paste having a sheet resistance of 2 mΩ / □, a film thickness of 15 μm, and a temperature coefficient of resistance of +3500 ppm / ° C. In the configuration in which the thick-film resistor layer 4 is formed from a paste containing copper nickel powder having a sheet resistance of 70 mΩ / □, a film thickness of / 15 μm, and a temperature coefficient of resistance of +20 ppm / ° C. The value was 93.1 mΩ and the temperature coefficient of resistance was +109 ppm / ° C. (average value).
[0073]
Example 1
The thick film resistor layer 13 and the thickness are formed on a rectangular insulating substrate 11 having a length of about 3.2 mm and a width of about 1.6 mm with a copper-nickel alloy paste having a sheet resistance of 30 mΩ / □, a film thickness of 15 μm, and a temperature coefficient of resistance of +50 ppm / ° C. In the thick-film low-resistance chip resistor on which the film upper surface internal electrode 14 was formed, the resistance value was 50.8 mΩ and the temperature coefficient of resistance was +93.5 ppm / ° C. (average value).
[0074]
Example 2
A thick film resistor layer 13 is formed on a rectangular insulating substrate 11 having a length of about 3.2 mm and a width of about 1.6 mm with a copper nickel alloy paste having a sheet resistance of 70 mΩ / □, a film thickness of 15 μm, and a temperature coefficient of resistance of +20 ppm / ° C. In the configuration of the thick-film low-resistance chip resistor in which the thick-film upper internal electrode layer 14 is formed of a copper-nickel alloy paste having a sheet resistance of 30 mΩ / □, a film thickness of 15 μm, and a resistance temperature coefficient of +50 ppm / ° C., the resistance value is 114 mΩ. , Temperature coefficient of resistance + 49.6 ppm / ° C (average value).
[0075]
As a result of this experiment, the resistance value of the conventional thick-film low-resistance chip resistor shown in FIG. 3 is increased by about 20%, but the temperature coefficient of resistance is significantly reduced (about 50% to 60%). confirmed.
[0076]
【The invention's effect】
According to the present invention, a thick film low resistance resistor having a low resistance temperature coefficient and a low resistance temperature coefficient of a thick film upper surface internal electrode layer laminated on a thick film resistor layer can be obtained.
[0077]
Further, the thick film upper surface internal electrode layer laminated on the thick film resistor layer has a low temperature coefficient of resistance, and a thick film low resistance resistor having a low resistance and a low temperature coefficient of resistance can be efficiently manufactured.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing one embodiment of a thick film low resistance chip resistor of the present invention.
FIG. 2 is a flowchart showing one embodiment of a method of manufacturing the same thick film low resistance chip resistor.
FIG. 3 is a longitudinal sectional view showing a conventional thick film low resistance chip resistor.
[Explanation of symbols]
11 Insulating substrate
12 Thick film lower surface internal electrode layer
13 Thick film resistor layer
14 Thick film upper surface internal electrode layer
17 End face internal electrode layer

Claims (9)

An insulating substrate;
A thick-film resistor layer having a low resistance and a low-resistance temperature coefficient characteristic formed on the upper surface of the insulating substrate;
A thick-film low-resistance resistor comprising: a thick-film upper-surface internal electrode layer having a low resistance and a low-resistance temperature coefficient characteristic, each of which is laminated on both ends of the thick-film resistor layer. An insulating substrate;
A thick film lower surface internal electrode layer formed at both ends of the lower surface of the insulating substrate;
A thick-film resistor layer having a low resistance and a low-resistance temperature coefficient characteristic formed on the upper surface of the insulating substrate;
A thick-film upper surface internal electrode layer having a low resistance and a low-resistance temperature coefficient characteristic, which is formed by being laminated on both ends of the thick-film resistor layer,
A thick-film low-resistance resistor comprising at least end-face internal electrode layers formed on both end faces of the insulating substrate connected to the thick-film upper-surface internal electrode layer and the thick-film lower-surface internal electrode layer. . 3. The thick film low resistance resistor according to claim 1, wherein the thick film resistor layer and the thick film upper surface internal electrode layer are copper nickel thick film layers. 3. The thick-film low-resistance resistor according to claim 1, wherein the thick-film resistor layer is a copper-nickel thick-film layer, and the thick-film upper internal electrode layer is a silver-palladium thick-film layer. The thick film resistor layer is
80 to 30 parts by weight of copper and 20 to 70 parts by weight of nickel, or a mixture of each element or an alloy powder thick film resistor element of copper and nickel,
1 to 10 parts by mass of a metal oxide with respect to 100 parts by mass of the entire thick film resistor element;
The thick-film low-resistance resistor according to any one of claims 1 to 4, further comprising at least 1 to 10 parts by mass of glass with respect to 100 parts by mass of the entire thick-film resistor element. A step of printing and baking a thick film paste containing copper nickel powder on the upper surface of the insulating substrate to form a thick film resistor layer of copper nickel alloy,
Printing and baking a thick film paste containing copper nickel powder on both ends of the thick film resistor layer to form a thick film upper surface internal electrode layer of copper nickel alloy on the thick film resistor layer at least. A method for manufacturing a thick-film low-resistance resistor, comprising: Forming a thick film lower surface internal electrode layer at both ends of the lower surface of the insulating substrate;
A step of printing and firing a thick film paste containing copper nickel powder on the upper surface of the insulating substrate to form a thick film resistor layer of a copper nickel alloy,
A step of printing and firing a thick film paste containing copper nickel powder on both ends of the thick film resistor layer to form a thick film upper surface internal electrode layer of copper nickel alloy on the thick film resistor layer,
Forming end face internal electrode layers connected to the thick film upper surface internal electrode layer and the thick film lower surface internal electrode layer on both end faces of the insulating substrate. Manufacturing method. A step of printing and baking a thick film paste containing copper nickel powder on the upper surface of the insulating substrate to form a thick film resistor layer of copper nickel alloy,
Printing and baking a thick film paste containing silver palladium powder on both ends of the thick film resistor layer to form a thick film upper surface internal electrode layer of a silver-palladium alloy on the thick film resistor layer at least. A method for manufacturing a thick-film low-resistance resistor, comprising: Forming a thick film lower surface internal electrode layer at both ends of the lower surface of the insulating substrate;
A step of printing and firing a thick film paste containing copper nickel powder on the upper surface of the insulating substrate to form a thick film resistor layer of a copper nickel alloy,
A step of printing and firing a thick film paste containing silver palladium powder on both ends of the thick film resistor layer to form a thick film upper surface internal electrode layer of a silver-palladium alloy on the thick film resistor layer,
Forming end face internal electrode layers connected to the thick film upper surface internal electrode layer and the thick film lower surface internal electrode layer on both end faces of the insulating substrate. Manufacturing method.

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