JPH03218604A - Manufacturing method of square plate type thin film chip resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a rectangular plate type thin film chip resistor.

Conventional technology In recent years, as the demand for electronic equipment to become lighter, thinner, shorter, and smaller has been increasing, in order to increase the mounting density of resistive elements on circuit boards, there are many square plate-type chip resistors that can be surface-mounted in a small size. In addition, in recent years, parts have become more precise and have lower noise, and the demand for square plate type chip resistors is increasing from the thick model type to the high precision, low noise thin film type. .

An example of a conventional manufacturing method for a small square plate type thin film chip resistor (cited from Susumu Kogyo's DATABOOK) is shown in FIG.

First, the conventional manufacturing process starts with a substrate receiving process A in which a heat-resistant insulating substrate 21 made of a high-purity anoremina substrate or the like is received. Next, a thin film resistor 22 such as N-Cr is placed on the insulating substrate 21. The thin film resistor 2.2 is formed into a resistor pattern 23 through a nupatta process B for forming the thin film resistor 2.2.
An etching process C is performed to shape the resistor pattern 23.
In order to make it a stable model, heat it at 350°C to 4°C in nitrogen, etc.
Atmospheric heat treatment step D is performed at a temperature of 00°C. Thereafter, in order to correct the resistance value of the resistance pattern to a predetermined value, a resistance value correction step E is performed in which a trimming groove 24 is formed in the resistance pattern by a laser trimming method or the like. Furthermore, in order to protect the resistance pattern 23, a thermosetting resin film 26
A protective coat forming step F is performed to form a protective coat. Next, as a preparation step for dividing the insulating substrate 21 and forming the end electrode layer 26, there is a scribing step G of forming grooves 27 for dividing the insulating substrate 21, and a scribing step G for forming grooves 27 for dividing the insulating substrate 21 into the strip-shaped substrate 26.
A primary substrate dividing step H is performed to divide the strip-shaped substrate 21' into 1', and sputtering or the like is used to form an end electrode layer 2 on the end face of the strip-shaped substrate 21'.
Then, electrode forming step I is performed to form electrode 6. Then, a plating layer 2 is applied to the exposed resistance pattern and the end electrode surface.
As a preparatory step for performing step 7, a secondary substrate dividing step J is performed in which the strip-shaped substrate 21' is divided into individual piece-shaped substrates 21''.
In order to prevent the exposed resistor pattern and end face electrode layer from being eaten away during soldering and to ensure reliability of solderability, an electrode plating process K is performed to form an electrode plating layer 27, and a rectangular plate-shaped thin film is formed. The chip resistor is completed.

Problems to be Solved by the Invention However, the rectangular plate type thin chip resistor produced by this process had the following problems.

(1) Since the resistive film is formed using Nupatta,
Continuous processing is difficult, and mass production requires a large number of Nupatta devices, making it about twice as expensive as thick-film chip resistors.

(2) Since the resistive film is heat-treated at 350°C to 400°C, a glass protective coat, which requires heat treatment above about 500°C, cannot be used, and a resin protective coat must be used. Therefore, their heat resistance is inferior to that of thick chip resistors.

(3) Substrates with dividing grooves, which are often used in thick square plate type chip resistors, are difficult to form thin films due to the unique undulations of the substrate between the dividing grooves. Thin film chip resistors are made by forming grooves for division by laser scribing on a substrate with little waviness and no dividing grooves. However, laser scribing not only impairs the aesthetic appearance of the chip resistor, but also tends to cause microcracks on the substrate due to thermal shock from the laser, which can lead to deterioration of the insulation.

(4) Since the end electrodes are formed by sputtering, the adhesion strength of the electrodes is weaker than the strength of the end electrodes of conventional thick chip resistors in which thick film silver electrodes are coated and fired. On the other hand, for conventional rectangular plate-type thin film chip resistors, a method has been considered in which a thick film end face electrode fired at a low temperature is applied and fired so as to overlap the thin film resistor as the end face electrode. This could not be realized due to the problem that the thin film resistor would be eaten away during firing.

The present invention solves these problems all at once; it is inexpensive, has good heat resistance due to the use of glass coating,
The present invention provides a rectangular plate-type thin film chip resistor with excellent substrate insulation and strong electrode strength during soldering.

Means for Solving the Problems In order to solve the above problems, the method for manufacturing a rectangular plate type thin film chip resistor of the present invention uses a chemically stable conductive method to form a pair of upper surface electrodes on a heat-resistant insulating substrate. printing and firing the material, and forming an undercoat glass using a pattern having a length equal to or less than the distance between the upper electrodes in order to smooth the surface of the heat-resistant insulating substrate between at least the pair of upper electrodes. a step of printing and firing a resistive material made of a metal organic material to form a thin film resistor overlapping a portion of the undercoat glass and the upper surface electrode; and a step of coating the resistor. A step of printing and firing an overcoat glass for protection, a step of modifying the resistance value to match the characteristics of the resistor, a step of dividing the primary substrate which is a preparation step for forming the end face electrodes, and a step of dividing the divided substrate. The edge electrode printing and firing process is used to form electrodes at the edges, the secondary board dividing process is a preparation process for electrode plating, and the process is used to prevent electrodes from being eaten away by soldering and to ensure reliability of solderability. The electrode plating process is sequentially performed.

action As a result, the following effects can be obtained.

(1) Thin film resistors can be formed continuously using a printing machine and a continuous firing furnace without using sputtering equipment, reducing manufacturing costs and producing square plates as inexpensive as thick film square plate chip resistors. (2) Since the thin film resistor is formed by printing a resistance material made of a metal-organic substance, galanu coat can be used as a protective coat, which makes it possible to provide a conventional rectangular plate type thin film chip resistor. Heat resistance can be improved compared to containers.

(3) The undercoat glass absorbs the undulation of the substrate between the dividing grooves, which is unique to divided grooved substrates, and makes the surface smooth. Therefore, it is not necessary to form dividing grooves by performing laser scribing on a smooth substrate without undulations as in the conventional method, so that the insulation properties of the substrate are improved.

(4) Since the thin film resistor is printed and fired after firing the thick film electrode on the top surface, the thin film resistor will not be eaten by the top electrode when firing the end face electrode, and the thick end electrode will be made stronger by firing. The strength of the end face electrode can be made equal to that of conventional thick film chip resistors.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a process diagram showing Embodiment 1 of the method for manufacturing a rectangular plate type thin film chip resistor of the present invention, FIG. 2 is a cross-sectional view of a product manufactured by the process of FIG. 1, and FIG. 4 is an explanatory diagram showing the heat resistance of the rectangular plate type thin film chip resistor of the present invention, FIG. 4 is an explanatory diagram showing the tensile strength of the end face electrode of the rectangular plate type thin film chip resistor of the present invention, and FIG. FIG. 3 is an explanatory diagram showing a change in resistance value due to a moisture resistance load test when a conductive material is used.

An embodiment of the present invention will be described with reference to FIG. First, 96 Anoremina substrate 1 with excellent heat resistance and insulation properties.
The process of accepting people went through. In order to divide the anoremina substrate 1 into strips and individual pieces, a dividing groove 2 (molded with a mold at the time of green sheeting) is formed. Next, a thick film of silver paint was screen-printed on the 96 anoremina substrate 1, and heated in a P/L/} type continuous firing furnace at a temperature of 600'C for a peak time of 6 minutes.
Process B was performed in which a pair of upper electrode layers 4 were formed by firing with a Grof 7 inole for N-OUT 45 minutes. Next, in order to smooth out the undulations and protrusions of the substrate between the pair of upper electrode layers 4, an undercoat glass paste was screen printed, and an in-line heat treatment was performed at a peak temperature of 900°C for 15 minutes in a penolet type continuous firing furnace. Step C was performed in which the undercoat glass layer 3 was formed by firing according to the OUT 2 hour profile. Next, a resistance paste made of a metal organic material containing Ru02 as a main component was screen printed so as to partially overlap the undercoat glass layer 3 and the upper electrode layer 4. Then, in order to remove only the organic components of the metal-organic resistance paste and bake only the metal components onto the undercoat glass layer, a continuous firing furnace of 640°C was used.
Step D was performed in which the resistor layer 6 was formed by firing at a temperature of 10 minutes at a peak time of 10 minutes and an IN-OUT time of 45 minutes using a Grof 7 inole.

Furthermore, in order to protect the resistor layer 4, an overcoat glass paste is screen printed so as to completely cover the resistor layer 4, and then the overcoat glass paste is screen printed in a penolet type continuous firing furnace.
At a temperature of 00'C, peak time 16 minutes, IN-OUT9
Firing was performed using a firing profile of 7 minutes for 0 minutes, and step E of forming an overcoat glass layer 6 was performed. Next, in order to equalize the resistance values of the resistor layer 4 between the upper electrode layers 5, a laser beam (
A resistance value correction step F was performed in which only the resistor layer 4 was destroyed using an oscillation frequency of 5 kHz and an output of 0.3 W.

Next, as a preparatory step for forming the end electrodes, a primary substrate dividing step G was performed in which the alumina substrate 1 was divided into strips to obtain strip-shaped anoremina substrates 1' in order to expose the end electrodes. Furthermore, the strip-shaped anoremina substrate 1
A thick silver paste was applied with a roller to the side surface of the upper electrode layer 6 so as to partially overlap with the upper electrode layer 6, and heated in a Venoret type continuous firing furnace at a temperature of 600°C with a peak time of 6 minutes and an IN-OUT of 45 minutes. An end face conductor paste printing/firing process H was performed in which the end face conductor paste was fired using a firing profile of 7 to form an end face electrode layer 8. Next, as a preparation step for the electrode plating process K, a secondary substrate dividing process fiJ is performed to divide the strip-shaped anoremina substrate 1' on which the end surface electrode layer 8 has been formed into individual pieces, and the individual piece-shaped anoremina substrate 1'' Finally, in order to prevent the exposed top electrode layer 5 and end electrode layer 8 from being eaten away during soldering and to ensure soldering reliability, Ni and Sn-Pb were coated by electrolytic plating. Electrode plating step K for forming plating layer 9 was performed.

Through the above steps, a rectangular plate type thin film chip resistor according to an embodiment of the present invention was fabricated.

The resistance variation, temperature resistance characteristics (TCR), current noise characteristics, and resistance change due to heat resistance test (460"0 10 minutes) of the rectangular plate type thin film chip resistor according to the embodiment of the present invention were compared with those of the conventional rectangular plate type thin film chip resistor. Comparison was made with a chip resistor.As a result,
It was found that the resistance value variation, TCR, and current noise characteristics are equivalent to conventional square plate type thin film chip resistors. Also,
As shown in FIGS. 3 and 4, it can be said that it is superior to conventional square plate type thin film chip resistors in terms of heat resistance and electrode strength.

Furthermore, since the undercoat glass layer is formed between the pair of top electrodes, the film thicknesses of the top electrode layer and the undercoat glass layer are almost the same, and the resistor layer is formed on a flat surface compared to Example 1. It is formed.

This improved the variation in resistance values.

(5% at 3σ / When a rectangular plate type thin film chip resistor was fabricated as a prototype, the resistance value hardly changed even after a long-term (10,000 hours) moisture resistance load test as shown in FIG.

In the example, the firing temperature of the undercoat was set to 900''.
C. The firing temperature of the metal organic resistance paste was 640°C, the firing temperature of the top conductor was 600'C, the firing temperature of the overcoat glass paste was 600°C, and the firing temperature of the end conductor paste was 600°C. The firing temperature is not limited.

Although the metal-organic resistance paste used is a resistance paste containing Ru02 as a main component, the metal-organic resistance paste is not limited thereto.

Further, although a silver-based thick film electrode paste was used for the top electrode layer and the end face electrode layer, a noble metal-based thick film electrode paste such as gold or platinum may be used.

Further, as shown in FIG. 6, by using a gold-based thin film conductive material for the upper electrode layer, the change in resistance value caused by a long-term (10,000 hours) moisture resistance load test can be significantly reduced.

Effects of the Invention As is clear from the above description, the present invention includes a step of printing and firing an undercoat glass to smooth the surface of a heat-resistant insulating substrate, and a step of printing and firing an undercoat glass to smooth the surface of a heat-resistant insulating substrate, and a step of printing and firing an upper surface electrode that overlaps a part of the undercoat glass. A step of printing and firing a chemically stable conductive material to form a resistor material made of a metal-organic material to form a thin film resistor overlapping a part of the upper surface electrode on the undercoat glass. a step of printing and firing, a step of printing and firing an overcoat glass to cover and protect the resistor, a step of modifying the resistance value to match the characteristics of the resistor, and a step of modifying the resistance value for forming end electrodes. A primary board dividing process which is a preparatory process, a final electrode printing and baking process for forming electrodes on the end faces of the divided boards, a secondary board dividing process which is a preparatory process for electrode plating, and an electrode eating process by soldering. Since it is configured to sequentially pass through the electrode plating process to ensure reliability of solderability and solderability, the following effects can be obtained.

(1) Thin film resistor patterns can be formed continuously using a printing machine and a vent-type continuous firing furnace without using sputtering equipment, increasing productivity and producing square plates as inexpensive as thick film square plate type chip resistors. type thin film chip resistors can be provided.

(2) Thin film resistors are printed and fired with a resistance material made of organic metals, so a glass coat can be used as a protective coat, resulting in improved heat resistance compared to conventional square plate type thin film chip resistors. .

(3) In conventional thin film chip resistors, it was necessary to form dividing grooves by laser scribing on a smooth substrate without undulations, but according to the present invention, by forming an undercoat glass layer, It can also be used on substrates with ridges and dividing grooves, improving the insulation properties of the substrate.

(4) Since the electrodes can be strongly formed by applying and baking a thick film end face paste, the strength of the end face electrodes can be made equal to that of a conventional thick model Chigg resistor.

(6) Furthermore, by using a thin gold thread conductive material for the upper electrode layer, changes in resistance value due to a long-term (10,000 hours) moisture resistance load test can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the manufacturing process of a rectangular plate type thin film chip resistor according to an embodiment of the present invention, and FIG. 2 is a sample manufactured by the method of manufacturing the rectangular plate type thin film chip resistor shown in FIG. 1. 3 is an explanatory diagram showing the heat resistance of the rectangular plate type thin film chip resistor of the present invention, FIG. 4 is an explanatory diagram showing the strength of the end electrode of the rectangular plate type thin film chip resistor of the present invention, Figure 5 shows the long-term (10
FIG. 6 is an explanatory diagram showing an example of the molding process of a conventional rectangular plate type thin film chip resistor. 1... 96 anoremina substrate, 1'... 96 anoremina substrate in the form of a strip, 1''... 96 anoremina substrate in the form of individual pieces, 2... Groove for division, 3... Undercoat Galanu layer, 4... Resistor layer, 5...
- Top electrode layer, 6... Overcoat glass layer, 7... Trimming groove, 8... Edge electrode layer, 9... River electrode plating layer.

Claims (3)

[Claims] (1) printing and firing a chemically stable conductive material to form a pair of upper surface electrodes on a heat-resistant insulating substrate;
printing and firing an undercoat glass using a pattern having a length equal to or less than the distance between the upper surface electrodes in order to smooth the surface of the heat-resistant insulating substrate between at least the pair of upper surface electrodes; A step of printing and firing a resistance material made of a metal-organic material to form a thin film resistor that partially overlaps the coat glass and the upper surface electrode, and printing an overcoat glass to cover and protect the resistor. a resistance value correction step for aligning the characteristics of the resistor; a primary substrate dividing step which is a preparation step for forming end surface electrodes; and a step for forming electrodes on the end surfaces of the divided substrates. end face electrode printing and firing process,
A rectangular plate type thin film chip characterized by sequentially passing through a secondary board dividing process which is a preparation process for electrode plating, and an electrode plating process to prevent the electrode from being eaten away by soldering and to ensure reliability of solderability. Method of manufacturing resistors. (2) The method for manufacturing a rectangular plate type thin film chip resistor according to claim 1, wherein the upper surface electrode is formed by printing and firing a gold-based thin film conductive material. (3) Claim 1, characterized in that the resistance value is modified by destroying the resistor covered by the overcoat with a laser beam that passes through the overcoat glass.
A method of manufacturing the rectangular plate type thin film chip resistor described above.