JPH08186013A - Method of manufacturing chip resistor - Google Patents

Abstract

PURPOSE: To enhance the shape dimension and precision without deteriorating the electrical characteristics of a resistor film by a method wherein the resistor film is printed with a glass paste mixed with an organic pigment to be baked for burning out the organic pigment. CONSTITUTION: Electrodes 2 are formed on an insulating substrate 1. Next, a resistor film 3 is so formed as to stride over the electrodes 2, 2 on the insulating substrate 1. Furthermore, the resistor film 3 is printed with a glass paste containing an organic pigment and then baked to form the first transparent glass film 4. Next, a trimming trench 5 is formed to adjust the resistance value of the resistor film 3. Furthermore, inside the trimming trench 5 and the first transparent film 4 are printed with a glass paste as the organic pigment to make the surface smooth and then baked to form the second transparent glass film 6. Next, a protective film 7 containing an inorganic pigment is formed on the second transparent film 6. Finally, an end face electrode 8 is formed on both end faces of the insulating substrate 1 moreover, an electrode film 9 is so formed as to cover these elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a chip resistor for protecting a resistor on an insulating substrate.

[0002]

2. Description of the Related Art As a conventional chip resistor and its manufacturing method, for example, there is one disclosed in Japanese Patent Publication No. 6-18121. This consists of forming a plurality of pairs of electrodes on an insulating substrate such as alumina, forming a resistance film so as to straddle each of these electrodes, and showing a high absorbance for the laser in the subsequent process on this resistance film. It forms a translucent glass containing a green inorganic pigment that facilitates trimming. In addition, the meaning of using a pigment here is to make it easy to confirm the position of translucent glass screen-printed.

After trimming with a laser or the like on the semitransparent glass film to adjust the resistance value,
After forming a black glass film containing a black inorganic pigment and having good concealment, plating resistance, and environment resistance on the semitransparent glass film, an end face electrode and a back electrode electrically connected to each of the above electrodes Is formed on the edge of the insulating substrate, and nickel or solder is plated on it.

[0004]

However, in such a conventional method of manufacturing a chip resistor, a part of the resistance film is removed by trimming, and before the resistance value is adjusted, it is semitransparent. A glass film is formed, and during the trimming, the laser energy of the trimming chemically decomposes the inorganic pigment contained in the translucent glass film, which adversely affects the resistance film electrically. There was a point.

Further, the black glass film is colored differently from the underlying semitransparent glass film (green), and if these positions are misaligned during printing, the chip resistors will be discolored in appearance and also when mounted. There is a problem in that the image recognition device has a problem in recognition and cannot be mounted at a predetermined position, which causes a trouble.

Further, the resistance value is adjusted by the trimming to form a black glass film directly on the semitransparent glass film, so that the resistance film is exposed to the black glass film side at the trimmed portion. However, there was a problem that the black inorganic pigment entered the exposed portion and caused a drift of the resistance value in each process, and the drift gradually increased, so that the change in the electrical characteristics of the resistance value increased. .

The present invention has been made in view of the above-mentioned conventional problems, and protects and trims the resistance film by removing the pigment of the inorganic metal oxide such as chromium oxide in the glass film. Etc., the appearance is good without deteriorating the electrical characteristics of the resistance film,
An object of the present invention is to obtain a method for manufacturing a chip resistor, which can form a smooth surface and can improve the shape and size and accuracy. Further, in the present invention, the pigment such as black is removed between the first glass film and the protective film so that a part of the first glass film removed by trimming does not directly contact the protective film mixed with the inorganic pigment. By doing so, the purpose was to make the resistance film more sufficiently protected.

[0008]

In the method of manufacturing a chip resistor according to the present invention, at least a pair of electrodes are formed on an insulating substrate, and a resistance film is formed on the insulating substrate so as to straddle the electrodes. Printing a glass paste mixed with an organic pigment on the resistance film and baking the paste to form a first transparent or semi-transparent glass film, and the resistance film through the first transparent glass film. Is removed to adjust the resistance value, and a glass paste mixed with an organic pigment is printed on the portion where the resistance film has been removed and the first transparent glass film, and the second paste is baked. To form a transparent or translucent glass film. Finally, a protective film containing an inorganic pigment is formed on the second transparent glass film.

Organic pigments which can be burned out by firing used in the present invention include phthalocyanine blue, phthalocyanine green, watching manganese red, naphthol (red), quinacridone (red), perylene (red), polyazo (yellow) and monoazo pigments. (Yellow) is used, and these are burned out by firing after printing.

[0010]

In the method of manufacturing a chip resistor according to the present invention, the first transparent or semitransparent glass film and the second transparent or semitransparent glass film formed on the resistance film are organic pigments instead of conventional inorganic pigments. Obtained by firing after printing a glass paste containing, the conventional inorganic pigment pigment remaining after firing, to facilitate the position of the portion where the glass paste is screen-printed, and the glass film after firing For the reason that it is transparent, it is obtained by containing only an organic pigment in the glass paste and burning out as hydrogen or carbon dioxide gas due to chemical bonding or decomposition during firing. Therefore, even if a part of the resistance film is exposed to the transparent glass film side due to trimming during resistance adjustment of the resistance film, the resistance film is adversely affected because the organic pigment has already disappeared. It is possible to realize stable resistance value characteristics and electrical characteristics.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a manufacturing process diagram showing a method of manufacturing a chip resistor according to the present invention, and a manufacturing process of a chip resistor will be described below with reference to this drawing.

First, an insulating substrate 1 made of ceramic, glass, alumina or the like as shown in FIG. 1A is prepared, and electrodes 2 made of a pair or a plurality of pairs of conductors are provided on the insulating substrate 1. It is formed as shown in FIG. 1B (electrode forming step). The conductor is Ag-P
A t-based or Ag-Pd-based conductive thick film paste is used.

Next, the insulating substrate 1 is placed so as to straddle the pair of electrodes 2 and 2 made of Ag-Pt type metal or the like.
The resistance film 3 is formed thereon as shown in FIG. 1C (resistance film forming step). The resistance film 3 is formed by printing a paste of, for example, ruthenium oxide (RuO ₂ ) based on, for example, 850 ° C.
Is formed by firing.

Further, a lead borosilicate glass-based glass paste containing an organic pigment such as phthalocyanine blue or phthalocyanine green is printed on the resistance film 3 and is further fired, as shown in FIG. 1 (d). Then, the first transparent glass film 4 is formed (first transparent glass film forming step). By the firing, the organic material in the glass paste burns out hydrogen, oxygen, carbon, and nitrogen, which are elements in the organic pigment contained in the lead borosilicate glass paste, at a firing temperature of, for example, 600 ° C. It becomes a glass film.

Next, as shown in FIG. 1E, the first transparent glass film 4 and the resistance film 3 are trimmed by laser or sand blasting to trimming grooves 5.
Is formed, and the resistance value of the resistance film 3 is adjusted (resistance value adjusting step). Further, in the trimming groove 5 and on the first transparent glass film 4, the same lead borosilicate as the organic pigment described above is used. A glass paste mixed with acid glass is printed so that the upper surface is smooth, and then baked to form a second transparent glass film 6 as shown in FIG. 1F (second transparent). Glass film forming step).

At the same time as described above, the organic pigment in the glass paste can be burned out at a high temperature by such firing, and a protective film in which an inorganic pigment is mixed is formed on the second transparent glass film 6. However, in order to maintain the hiding power, the inorganic pigment must remain after firing or baking. However, the inorganic pigment and the resistance film 3
The resistance value is stable in terms of thermal or overload characteristics because there is no contact at the exposed part by trimming. Therefore, this organic pigment does not have a chemical or physical adverse effect on the resistance film 3 exposed on the transparent glass films 4 and 6 side.

Then, a protective glass film containing an inorganic pigment or a protective film 7 as a protective synthetic resin film is formed on the second transparent glass film 6 as shown in FIG. 1 (g). Even if this protective film 7 is formed by printing and firing a glass paste containing an inorganic pigment such as chromium oxide, the color (for example, black) of the inorganic pigment remains, so that the letters and symbols of the white pigment on top of this. By performing printing of, it is possible to add distinctiveness by color contrast.

Next, the end surface electrodes 8 are formed on the both end surfaces of the insulating substrate 1 with Ag-based paste so as to cover a part of the insulating substrate 1, and nickel plating or solder is applied to cover the end surface electrodes 8. As shown in FIG.
A chip resistor as shown in (h) will be formed.

[0019]

As described above, according to the present invention, at least a pair of electrodes are formed on an insulating substrate, and a resistance film is formed on the insulating substrate so as to straddle each of the electrodes. A glass paste mixed with an organic pigment is printed thereon and baked to form a first glass film, and part of the resistance film is removed through the first glass film to adjust the resistance value. Further, since the protective glass film mixed with the inorganic pigment is formed on the second glass film, the resistance film is protected and trimmed by the glass film containing the organic pigment that can be burned out by firing. By doing so, it is possible to easily obtain what has a good appearance, can form a smooth surface, and can improve the shape dimension and accuracy without deteriorating the electrical characteristics of the resistance film. .

With respect to the resistance film that is partially exposed after the resistance value adjustment, a glass paste mixed with an organic pigment is printed on the trimming mark and the first glass film and fired. , With organic pigment burnout,
It is also possible to prevent the characteristic change of the resistance value due to the mixing of the inorganic pigment in the trimming trace.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram showing a method of manufacturing a chip resistor according to an embodiment of the present invention.

[Explanation of reference numerals] 1 insulating substrate 2 electrode 3 resistance film 4 first transparent glass film 5 trimming groove 6 second transparent glass film 7 protective film (protective glass film)

Claims (2)

[Claims] 1. An electrode forming step of forming at least a pair of electrodes on an insulating substrate, a resistive film forming step of forming a resistive film on the insulating substrate so as to straddle each electrode, and a resistive film forming step on the resistive film. A first glass film forming step of forming a first transparent or semi-transparent glass film in which the glass paste containing an organic pigment is printed and baked to burn out the organic pigment; and the first glass film. A resistance value adjusting step of adjusting a resistance value by removing a part of the resistance film via
A method of manufacturing a chip resistor, comprising: performing a protective film forming step of forming a protective film mixed with an inorganic pigment on the portion where the resistive film is removed and the first glass film. 2. A glass paste containing an organic pigment is printed on the portion where the resistance film is removed and the first glass film between the resistance value adjusting step and the protective film forming step,
The method of manufacturing a chip resistor according to claim 1, further comprising a second glass film forming step of forming a second transparent or semi-transparent glass film by baking the organic pigment to burn out.