JP4828710B2 - Chip resistor and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chip resistor formed by dividing an insulating substrate on which a resistor film is arranged, and a method for manufacturing the chip resistor.
[0002]
[Prior art]
Conventionally, this type of chip resistor is formed by the following procedure.
First, for example, a material paste containing glass frit and a conductive material is screen-printed on the back and front surfaces of an insulating substrate made of porcelain containing 96% alumina or more, and this is fired at, for example, about 850 ° C. A back electrode film and a surface electrode film of about -12 μm are formed. Next, a material paste containing glass frit and a conductive material is screen-printed between the pair of surface electrode films, and then fired at 850 ° C. to form a resistance film.
[0003]
Then, an undercoat film is formed on the resistance film. This undercoat film is formed by screen printing with a material paste containing lead borosilicate glass or the like and baked at about 600 ° C. to form a film having a thickness of 8 to 12 μm. A laser is applied to the resistance film from above the undercoat film to form a trimming groove for adjusting the resistance value, and further, a screen printing process of material paste and a baking process at about 600 ° C. And a primary break is formed in a strip shape along the dividing groove in the primary direction of the insulating substrate.
After this, screen printing is performed on the end face with a material paste containing glass frit and a conductive material, baking is performed at about 600 ° C. to form an end face electrode film having a thickness of 10 to 12 μm, and divided into individual chips by secondary breaks. This completes the chip resistor.
[0004]
[Problems to be solved by the invention]
In the conventional chip resistor, after the surface electrode film is formed, each step of forming a resistance film, an undercoat film and a protective coat film is performed, and the process is repeated several times at a high firing temperature such as 600 ° C. and 850 ° C. As a result, the conductive material such as silver or lead contained in the surface electrode film diffuses into the resistance film, thereby changing the electrical characteristics such as the resistance value.
[0005]
The present invention solves the problems as described above, and the problem is that the resistance value variation in the product is small and high in accuracy, and the resistance can be reduced even by the baking process of the protective coat film and the side electrode after trimming adjustment. An object of the present invention is to provide a chip resistor capable of preventing the value from deviating from a predetermined range and reducing the occurrence rate of defective products, and a manufacturing method thereof.
[0006]
[Means for Solving the Problems]
In the present invention, in order to solve the above-described problem, a chip-type resistor in which a surface electrode film is formed on both ends of the upper surface of an insulating substrate and the surface electrodes on both ends are connected to form a resistance film. but it is formed in the crystallization glass comprising becomes higher glass frit than the firing temperature of the resistive film softening temperature below after crystallization, the resistive film at a temperature lower than the crystal glass of table electrode film is obtained by forming an amorphous glass containing glass frit softens, chip resistors are provided, characterized in that.
Thus, as a material for the surface electrode film and the resistance film, a chip-type resistor combining crystallized glass and amorphous glass is novel. In the firing when forming, the conductive material contained in the surface electrode film or the resistance film can be prevented from diffusing into the other film. By the way, crystallized glass is glass in which crystals are intentionally deposited in glass, for example, having a higher heat resistance or higher mechanical strength than amorphous ones. Traditionally, it has been used as a material for glass tableware and glass pans.
[0007]
Further, in the present invention, in a method of manufacturing a chip resistor having a surface electrode film, a resistance film, an undercoat film, and a protective coat film on the upper surface of the insulating substrate, after it is crystallized on the surface of the insulating substrate. a front electrode film forming step of firing the crystallized glass becomes higher Garasufuri' bets paste material than the firing temperature of the resistive film softening temperature described later with Nurigi, the surface electrodes disposed to be connected from the top of the table electrode film provide manufacturing method of the chip resistor which comprises a resistive film forming step of firing the amorphous glass by Nurigi paste material Garasufuri' you want to soften at a temperature lower than the crystalline glass layer, the Is done.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
In the chip resistor of the present invention, the crystallization rate of the crystallized glass contained in the surface electrode film is preferably about 75 to 95%.
[0009]
In the chip resistor of the present invention, the undercoat film formed of glass so as to cover the resistance film, and the glass so as to cover a part of the surface electrode film and the entire resistance film and the undercoat film. You may comprise so that the formed protective coating film and side electrode may be included.
[0010]
The glass in the undercoat film, the protective coat film, and the side electrode film may be either crystallized glass or amorphous glass, but more preferably amorphous glass. Even if a film is formed by firing once, the glass film has a softening point at about 600 ° C., and therefore, after the glass film is formed, mutual diffusion occurs between the undercoat and the protective coat due to heating. The effect of improving the adhesiveness and further improving the adhesion between the side electrode and the substrate can be obtained.
[0011]
In the production method of the present invention, conditions such as the firing temperature and firing time of the surface electrode film can be appropriately selected according to the composition so that crystallized glass is formed.
Further, in the production method of the present invention, the firing temperature when forming the undercoat film and the protective coat film is appropriately selected according to the composition, but from the softening point of the glass frit in the resistance film. It is preferable that the temperature be lower. As a result, the glass in the resistance film does not soften even during firing when forming the undercoat film, the protective coat film, and the side electrode film, so that the conductive material contained in the resistance film is applied to the undercoat film and the surface electrode film. It becomes possible to suppress diffusion.
[0012]
In the production method of the present invention, the firing temperature when forming the resistance film, the undercoat film, the protective coat film, and the side electrode film may be lower than the softening point of the crystallized glass in the surface electrode film. preferable. As a result, the crystallized glass in the surface electrode film does not soften during firing when forming the resistance film, the undercoat film, the protective coat film, and the side electrode film, so the undercoat of the conductive material contained in the surface electrode film The effect of suppressing diffusion into the film and the resistance film is further enhanced.
[0013]
【Example】
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 3 is a cross-sectional view of the chip resistor 10 of the present invention.
In FIG. 3, a chip resistor 10 includes an insulating substrate 11 made of porcelain containing 96% alumina or more, surface electrode films 12 and 13 containing crystallized glass formed on both ends of the surface of the insulating substrate 11, A resistance film 14 including amorphous glass formed to connect the surface electrode films 12 and 13 to cover a part of them, and an undercoat film 15 formed of amorphous glass so as to cover the resistance film. A protective coating film 17 formed of amorphous glass so as to cover a part of the surface electrode films 12 and 13, the undercoat film 15 and the resistance film 14, and side electrodes 18 formed on the end face of the insulating substrate 11 19 and back electrode films 20 and 21 formed on both ends of the back surface of the insulating substrate 11, and the resistance film 14 is provided with a trimming groove 16 which is engraved with the undercoat film 15.
[0014]
Next, a manufacturing method of the chip resistor 10 will be described with reference to FIGS.
FIG. 1 is a perspective view of one chip in which surface electrode films 12 and 13 are provided on an insulating substrate 11, and FIGS. 2A to 2E are plan views of one chip in a manufacturing process. First, an insulating substrate containing 96% or more of alumina and having front and back side grooves engraved in the primary direction and the secondary direction is prepared, and the back side thereof is made of a paste material containing a conductive material and glass frit. Screen printing is performed and baking is performed at about 850 ° C. to form a back electrode.
[0015]
Next, as shown in FIG. 1 and FIG. 2A, on the surface of the insulating substrate, for example, VO—CuO—PbO—SiO—MnO having a softening temperature of about 570 ° C. and a crystallization temperature of about 850 ° C. and glass frit, TiO _2, ZrO ₂ or the like of the accelerating agent for accelerating crystallization with (5-15% by weight relative to the glass frit), a screen printed with a paste material containing a conductive material such as Ag-Pd And is cooled while controlling the temperature so that the glass material is crystallized by baking at about 850 ° C., thereby forming the surface electrode films 12 and 13 on both ends of the surface.
Here, the glass frit in the surface electrode films 12 and 13 is made of a material that is crystallized at a temperature substantially equal to or lower than the temperature at which the surface electrode films 12 and 13 are fired. The glass frit is preferably made of a glass material whose softening temperature is higher than the firing temperature of the resistance film 14 after crystallization.
[0016]
Next, as shown in FIG. 2B , for example, SiO—PbO—B having a softening temperature of about 650 ° C. is connected so as to cover a part of the pair of surface electrode films 12 and 13. Screen printing is performed with a paste material containing a glass frit such as ₂ O ₃ and a conductive material such as RuO ₂ —Pb ₂ or RuO _2, and the temperature is set so that the glass material becomes amorphous by baking at about 850 ° C. As a result, the resistance film 14 having a film thickness of about 5 to 15 μm is formed. Here, the resistance film 14 is preferably fired at a temperature lower than the softening temperature of the crystallized glass in the surface electrode films 12 and 13. The glass frit used for the resistance film 14 is made of a glass material that softens at a lower temperature than the crystallized glass in the surface electrode films 12 and 13.
[0017]
Further, as shown in FIG. 2 (c), a glass such as SiO—PbO—B ₂ O ₃ having a softening temperature of about 560 ° C. is screen-printed on the resistance film 14, and this is performed at about 600 ° C. By baking and cooling so that the glass material becomes amorphous, the undercoat film 15 having a film thickness of about 5 to 15 μm is formed. The firing temperature of the undercoat film 15 and the glass softening temperature are preferably lower than the glass softening temperature of the resistance film 14.
[0018]
Subsequently, the undercoat film 15 is irradiated with a laser to perform trimming for adjusting the resistance value to form a trimming groove 16, and a protective coat film 17 is formed thereon. Although not shown, the protective coat film 17 can be composed of a middle coat film and an overcoat film. In this case, the middle coat film is formed by screen-printing glass such as SiO—PbO—B ₂ O ₃ having a softening temperature of about 560 ° C., and firing it at about 600 ° C. so that the glass material becomes amorphous. On the other hand, the protective coating film is formed by screen-printing glass such as SiO—PbO—B ₂ O ₃ —Al ₂ O ₃ having a softening temperature of about 550 ° C., and firing it at about 600 ° C. It is formed by cooling so that the glass material becomes amorphous.
[0019]
After the formation of such a protective coating film, it breaks into strips along the primary dividing grooves in the insulating substrate so as to cover the end surface of the insulating substrate and on part of the front electrode film and the back electrode film. The chip-type resistor 10 is obtained by forming the side electrodes 18 so as to overlap, breaking the insulating substrate with a dividing slit in the secondary direction, dividing it into individual chips, and forming the electrode plating films 22 and 23. .
[0020]
【The invention's effect】
In the present invention, since the glass in the surface electrode film is crystallized glass, the glass of the resistance film partially overlapping on the surface electrode film is amorphous glass. The conductive material contained in the surface electrode film or the resistance film can be prevented from diffusing into the other film. Therefore, compared with the conventional product in which the glass of the surface electrode film and the resistance film is made of amorphous glass, the electrical characteristics such as the resistance value are stabilized, the variation in resistance value in the product is reduced, and the accuracy is increased. The firing process of the protective coating film and side electrode after trimming adjustment can also prevent the resistance value from deviating from the predetermined range and reduce the incidence of defective products.
[Brief description of the drawings]
FIG. 1 is a perspective view of one chip in which a surface electrode film is provided on an insulating substrate of the present invention.
FIGS. 2A to 2E are plan views of one chip in a manufacturing process.
FIG. 3 is a longitudinal sectional view of a chip resistor according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Chip type resistor 11 Insulating substrate 12, 13 Surface electrode film 14 Resistor film 15 Undercoat film 16 Trimming groove 17 Overcoat film 18, 19 End electrode film 20, 21 Back electrode film 22, 23 Electrode plating film

Claims (6)

In a chip resistor in which a surface electrode film is formed on both ends of the upper surface of the insulating substrate, and a resistance film is formed by connecting the surface electrodes on both ends,
Table electrode film, it is formed in the crystallization glass comprising becomes higher glass frit than the firing temperature of the resistive film softening temperature below after crystallization,
The resistive film is obtained by forming an amorphous glass containing a glass frit which softens at a temperature lower than the crystal glass of Table electrode film,
A chip-type resistor characterized by that. Includes a glass frit VO-CuO-PbO-SiO- MnO of the crystallized glass, Chip resistor according to claim 1 glass frit of the amorphous glass is intended to include SiO-PbO-B ₂ O ₃ .   An undercoat film formed of glass so as to cover the resistive film; and a protective coat film formed of glass so as to cover a part of the surface electrode film and the entire resistive film and the undercoat film. The chip-type resistor according to claim 1 or 2. In the method of manufacturing a chip resistor comprising a surface electrode film, a resistance film, an undercoat film, and a protective coat film on the upper surface of the insulating substrate,
A front electrode film forming step of the it to the surface of the insulating substrate is fired Nurigi to crystallized glass becomes higher Garasufuri' bets paste material than the firing temperature of the resistive film softening temperature below after crystallization,
A resistive film forming step of calcining the amorphous glass by Nurigi the Garasufuri' bets paste material which softens at a temperature lower than the crystal glass of the surface electrode film arranged to be connected from the top of the table electrode film,
A method for manufacturing a chip resistor, comprising: The glass frit paste material used in the electrode film formation step includes a conductive material and a crystallization accelerator, and the glass frit paste material used in the resistance film formation step includes a conductive material. 5. A method for producing a chip resistor according to 4. Wherein the baking temperature in the step of forming step and the protective coating layer for forming the undercoat layer, to claim 4 or 5, characterized in that a temperature lower than the softening point of the glass frit in the resistive film Of manufacturing a chip resistor.

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