JPH10275717A - Manufacture of chip resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a chip resistor in which a resistance value of a resistance film is adjusted without forming a cut groove. SOLUTION: A resistance value of a resistance film 3 is adjusted by sticking powder P1, supplied from a powder supplying mechanism 13, onto the resistance film 3 formed on an insulating substrate 1, so that the resistance value is adjusted without forming a conventional cut groove on the resistance film. Thereby, generation of crack caused by peeling the resistance film from an insulating substrate and deterioration of strength of the resistance film due to influence of the cut groove is avoided, and a chip resistor of high quality and reliability is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a chip resistor having improved resistance value adjustment.

[0002]

2. Description of the Related Art Conventionally, in this type of chip resistor, a conductor film for an extraction electrode and a resistor film are formed in a predetermined arrangement on an insulating substrate having a size corresponding to the number of chips, and each resistor film is trimmed. After adjusting the resistance value, a protective film is formed to cover the conductor film for the extraction electrode and the resistance film, and this is cut into individual chips, and external electrodes are formed at both ends of the chip. .

In the above resistance value adjusting step, the resistance value of the resistance film is detected while using the conductor film for an extraction electrode as a detection electrode.
This is implemented by forming an L-shaped or linear cut groove in the resistive film with a laser beam such as AG.

[0004]

In the above-described conventional resistance value adjusting method, since an L-shaped or linear cut groove is formed in the resistive film itself, a portion around the cut groove of the resistive film is separated from the insulating substrate. In addition, when the dimension of the cut groove is increased, the strength of the resistive film is reduced, and a crack may be generated.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of manufacturing a chip resistor capable of adjusting a resistance value of a resistance film without forming a cut groove. .

[0006]

In order to achieve the above object, the present invention relates to a method of manufacturing a chip resistor for forming a resistive film on an insulator and then adjusting the resistance value of the resistive film. The main feature is that the resistance value of the resistive film is varied by attaching particles containing a metal component to the resistive film thus formed, thereby adjusting the resistance value.

According to the present invention, the resistance value of the resistive film is varied by attaching particles containing a metal component to the resistive film formed on the insulator, thereby adjusting the resistance value. The resistance value can be adjusted without forming a groove in the resistance film.

[0008]

1 to 7 show one embodiment of the present invention. Hereinafter, a method of manufacturing a chip resistor according to the present embodiment will be described with reference to the drawings.

In manufacturing, first, an insulating substrate 1 having a size corresponding to the number of pieces as shown in FIG. 1 is prepared.
The insulating substrate 1 is formed by applying a ceramic slurry prepared by mixing a ceramic powder such as Al ₂ O ₃ , a binder, a solvent, and the like into a sheet by a method such as a doctor blade method or a screen printing method, and drying the coated slurry. And fired.

Next, as shown in FIG. 2, a rectangular lead electrode conductive film 2 is formed on the upper surface of the insulating substrate 1 in a number and arrangement corresponding to the number of holes. This conductor film 2 for an extraction electrode
Is prepared by applying an electrode paste prepared by mixing a powder containing a metal component such as Ag and Ni, a binder, a solvent, and the like, in a predetermined shape by a method such as a screen printing method, and then drying and firing the electrode paste. Is done. Of course, a similar conductive film may be formed by a thin film method such as vapor deposition, sputtering, or electroless / electrolytic plating while masking unnecessary portions.

Next, on the upper surface of the insulating substrate 1 after the formation of the conductive film, as shown in FIG. A rectangular resistance film 3 is formed. The resistive film 3 is formed by applying a resistive paste prepared by mixing a powder containing a metal component such as ruthenium oxide, a binder and a solvent in a predetermined shape by a method such as a screen printing method, and drying and firing the resistive paste. Created by Of course, a similar resistance film may be formed by a thin film method such as vapor deposition, sputtering, electroless plating, or electrolytic plating while masking unnecessary portions.

Next, the resistance value of each resistance film 3 formed on the insulating substrate 1 is adjusted using an apparatus as shown in FIG. Incidentally, in the figure, 11 is a resistance value detector, 12 is a detection terminal of the resistance value detector 11, and 13 is a powder feeder.
The powder feeder 13 stores a powder P1 containing a metal component (hereinafter simply referred to as powder P1), for example, a powder containing a metal component such as ruthenium oxide, or a powder containing a mixture of the powder and a ceramic powder such as PbO + MgO. Storage unit 13a
A powder deriving unit 13b for deriving the powder P1 in the powder storage unit 13a in a unit amount; and a nozzle 1 for supplying the powder P1 derived by the powder deriving unit 13b toward the resistive film 3.
3c, and the powder deriving unit 13b is controlled based on the resistance value detected by the resistance value detector 11.

When adjusting the resistance value, the detection film 12 is brought into contact with the lead electrode conductor films 2 located on both sides of the resistance film 3 to detect the resistance value of the resistance film 3, and the resistance film 3 is heated by the heater. The powder P1 is supplied from the powder supply device 13 toward the resistance film 3 while being heated by heat or the like. As a result, the supplied unit amount of the powder P1 is bonded to the surface of the resistive film 3 and its resistance value fluctuates. This powder supply is intermittently repeated until the value detected by the resistance value detector 11 reaches a predetermined value. Here, the resistance value of the resistive film 3 is adjusted by reducing the resistance value of the resistive film 3 by adhering the powder P1. It is desirable to set it to a value.

Next, as shown in FIG. 5, an insulating protective film 4 is formed on the entire upper surface of the insulating substrate 1 after the resistance value adjustment. The protective film 4 is formed by applying a glass paste mainly composed of SiO ₂ or the like in a layered manner by a screen printing method or the like and baking it, or by applying a resin paste such as an epoxy resin and curing the same. Created.

Next, the insulating substrate 1 after the formation of the protective film is cut along a virtual cutting line to obtain a unit chip 5 as shown in FIG. For this cutting, a dicing device capable of cutting by a rotating blade such as a diamond wheel, a scribing device capable of cutting by irradiation laser light, or the like is used. The unit chip 5 has a resistance film 5b on the upper surface of a rectangular insulating element 5a, and has extraction electrodes 5c on both sides in the longitudinal direction, and the resistance film 5b and the extraction electrode 5c are protected by a protective film 5d having a flat surface. Covered. Further, the edge of the extraction electrode 5c is exposed at each of the longitudinal end surfaces of the unit chip 5.

Next, a large number of unit chips 5 are barrel-polished at once. By this polishing, the corners and ridges of the unit chip 5 are rounded, and the protective film 5d, which is more easily polished than the insulating element 5a and the extraction electrode 5c, is entirely polished to expose the edge of the extraction electrode 5c. It will be noticeable.

Next, as shown in FIGS. 7 (a) and 7 (b), external electrodes 6 are formed on both ends in the longitudinal direction of the unit chip 5 after polishing, and are connected to the exposed end edges of the extraction electrode 5c. . The external electrode 6 is prepared by applying an electrode paste prepared by mixing a powder containing a metal component such as Ag or Ni, a binder, a solvent, or the like, in a predetermined shape by a method such as a dipping method, and drying and firing the electrode paste. Created by Of course, a similar conductive film may be formed by a thin film method such as vapor deposition, sputtering, or electroless / electrolytic plating while masking unnecessary portions.

A chip resistor having a predetermined resistance value is manufactured as described above. A solder film may be formed on the surface of the external electrode 6 by the same method as the external electrode 9 if necessary. Further, by repeating the step of forming the protective layer 4 twice, it is possible to form a protective film having a two-layer structure, for example, a lower layer of glass and an upper layer of resin.

As described above, according to the above-described manufacturing method, the resistance value is adjusted by adhering the powder P1 to the resistance film 3 formed on the insulating substrate 1, so that the conventional cut groove can be formed. The resistance value can be adjusted without forming the resistive film. Therefore, it is possible to provide a high-quality and highly reliable chip resistor by preventing the resist film from peeling off from the insulating substrate or reducing the strength of the resistive film due to the effect of the cut groove and causing cracks. it can.

In the above embodiment, the powder P1 containing a high-resistance metal component is attached to the resistance film 3. However, the same resistance value can be obtained by using a powder containing a low-resistance metal component as a material. Adjustments can be made.

In the above-described embodiment, the powder P1 is attached to the resistance film 3 to adjust the resistance value. However, any other material can be used as long as particles containing a metal component can be attached to the resistance film. The resistance value can be adjusted by the method.
A specific example will be described below with reference to FIGS.

In the method shown in FIG. 8, the resistance value is adjusted by evaporating the metal solution F and adhering the evaporated particles P2 to the resistance film 3, and 21 in the figure denotes the resistance value. A detector 22 is a detection terminal of the resistance value detector 21;
Is an evaporating particle feeder. This evaporating particle supply device 23
A solution storage unit 23 storing a metal solution F prepared by adding a powder containing a high-resistance metal component such as ruthenium oxide to an organic solvent.
a and a heater 23b for heating and evaporating the metal solution F
And the duct 23c for guiding the evaporated particles P2 toward the resistance film 3
And a shutter 23d for opening and closing the opening of the duct 23c
And the shutter section 23d is provided with the resistance value detector 2
The control is performed based on the resistance value detected in step (1).

When adjusting the resistance value, the detection terminals 22 are respectively brought into contact with the lead electrode conductor films 2 located on both sides of the resistance film 3 to detect the resistance value of the resistance film 3 while the resistance film 3 is heated. In a state of being heated by heat or the like, the evaporated particles P2 are supplied from the evaporated particle supply device 23 toward the resistance film 3. As a result, the supplied evaporated particles P2 are bonded to the surface of the resistance film 3, and the resistance value fluctuates. The supply of the evaporated particles is continued until the value detected by the resistance detector 21 reaches a predetermined value. Here, the resistance value of the resistive film 3 is adjusted by reducing the resistance value of the resistive film 3 by the attachment of the evaporated particles P2. Therefore, the initial resistance value of the resistive film 3 formed on the insulating substrate 1 allows for the decrease. It is desirable to set it to a default value. Of course, the same resistance value adjustment can be performed by evaporating a solution containing a low-resistance metal component.

In the method shown in FIG. 9, the material plate T is irradiated with laser light LB, and metal particles (molecules or atoms) P3 generated by laser ablation are attached to the resistance film 3 to adjust the resistance value. As shown in the figure, 31
Is a resistance value detector, 32 is a detection terminal of the resistance value detector 31,
Reference numeral 33 denotes a laser oscillator made of a pulse laser such as YAG or excimer, LB denotes a laser beam, T denotes a material plate containing a high-resistance metal component such as ruthenium oxide serving as a target for laser ablation, and the laser oscillator 33 denotes a resistance detector. Control is performed based on the resistance value detected at 31.

When adjusting the resistance value, the detection terminal 32 is brought into contact with each of the lead electrode conductor films 2 located on both sides of the resistance film 3 to detect the resistance value of the resistance film 3, and the resistance film 3 is heated. While heated by heat, etc., the laser oscillator 3
The laser beam LB is irradiated from 3 onto the material plate T. As a result, ablation occurs in the material plate T due to the energy of the irradiation laser beam LB, and the ablated metal particles (molecules or atoms) P3 are bonded to the surface of the resistance film 3 to change the resistance value. This laser ablation is continued until the value detected by the resistance detector 31 reaches a predetermined value. Here, the resistance value of the resistance film 3 is adjusted by reducing the resistance value of the resistance film 3 by the adhesion of the metal particles P3. Therefore, the initial resistance value of the resistance film 3 formed on the insulating substrate 1 is expected to correspond to this decrease. It is desirable to set it to a default value. Of course, the same resistance value adjustment can be performed by irradiating a laser beam to a material plate containing a low-resistance metal component to generate ablation.

[0026]

As described in detail above, according to the present invention,
Since the resistance value can be adjusted without forming the cut groove in the resistive film, it is possible to avoid the resist film from being separated from the insulator or the strength of the resistive film being reduced due to the influence of the cut groove to cause a crack. Thus, a high-quality and highly reliable chip resistor can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of an insulating substrate according to the present invention.

FIG. 2 is a view showing a conductive film forming step according to the present invention.

FIG. 3 is a view showing a resistive film forming step according to the present invention.

FIG. 4 is a diagram showing a resistance value adjusting step according to the present invention.

FIG. 5 is a view showing a protective film adjusting step according to the present invention.

FIG. 6 is a perspective view of a cutting tip according to the present invention.

FIG. 7 is a diagram showing an external electrode forming process according to the present invention and a longitudinal sectional view of a chip resistor.

FIG. 8 is a diagram showing another resistance value adjusting method.

FIG. 9 is a diagram showing another resistance value adjusting method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating substrate, 2 ... Conductor film for extraction electrodes, 3 ... Resistive film, 4
... Protective film, 5 ... Unit chip, 6 ... External electrode, 11 ... Resistance detector, 12 ... Detection terminal, 13 ... Powder feeder, P1 ...
Powder containing metal component, 21: resistance value detector, 22: detection terminal, 23: evaporating particle feeder, P2: evaporating particle, 31 ...
Resistance value detector, 32: detection terminal, 33: laser oscillator,
LB: laser beam, T: material plate, P3: metal particles.

Claims (4)

[Claims] In a method of manufacturing a chip resistor for adjusting a resistance value after forming a resistance film on an insulator, particles including a metal component are attached to the resistance film formed on the insulator. A method for manufacturing a chip resistor, wherein the resistance value of the resistance film is varied to adjust the resistance value. 2. The method according to claim 1, wherein the particles containing the metal component are powders containing the metal component. 3. The method for manufacturing a chip resistor according to claim 1, wherein the particles containing a metal component are particles evaporated from a metal solution. 4. The method for manufacturing a chip resistor according to claim 1, wherein the particles containing a metal component are particles generated by laser ablation.