JPH0618126B2 - Manufacturing method of chip resistor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a chip resistor having high shape accuracy and excellent reliability.

(Prior Art and Problems to be Solved) Chip resistors are widely used as one component of electronic components such as hybrid ICs, but recently, with the increase in density of electronic components, smaller and more highly precise shapes have been developed. It has come to be requested.

Conventionally, a method made as a method of manufacturing a chip resistor is to provide slits in the longitudinal direction at predetermined intervals in the width direction on the substrate, and the substrate alone or in a laminated state,
This is a method of forming a side electrode by printing or dipping a conductor paste on the inner wall of the slit, forming a resistor on the surface of the substrate, and then mechanically separating it into individual chips.

However, since this manufacturing method divides the substrate by mechanical operation, the substrate may be chipped or burred during the division, and it is impossible to accurately form a chip with a size of about 2.0 × 1.2 mm or less. is there. Further, the conventional method of forming by dividing the through hole is also not practical because the shape accuracy is poor.

In addition, even when the side surface electrode is formed with a thin film, it takes a long time to form a thin film, and there is a problem in electrical contact due to the material surface of the resistor material and the side surface conductor material, which is not practical in terms of reliability. There is a point.

In addition, the side electrode may be plated for the purpose of improving the solderability of the side electrode, but the conventional plating is a barrel plating method, and the plating thickness of the side electrode is not uniform and fluctuates. In this case, there is a problem in that the chips are rubbed against each other and a mark is formed on the back surface of the chip, resulting in poor insulation on the back surface of the chip and insufficient reliability.

Further, since the chip resistor is an extremely small product, it is difficult to handle, and there is a problem that the parts rub against each other even in the manufacturing stage, and a method that can be easily handled is demanded.

Further, in the case of a small chip resistor, the surface area becomes small and heat is generated, so that the power consumption is limited, and the small resistor area causes a problem of noise generation.

The present invention has been made to solve these problems, and an object of the present invention is to provide a manufacturing method capable of easily obtaining a small-sized, high-performance chip resistor having high shape accuracy.

(Means for Solving the Problems) The present invention has the following configuration in order to achieve the above object.

That is, in a method of manufacturing a chip resistor in which a large number of chip resistors are manufactured at one time, manufacturing is performed in the following order of steps.

(a) For a ceramic substrate having a plurality of slit-shaped through holes formed in parallel at regular intervals, a side surface electrode is provided on the inner surface of the through hole, and the peripheral surface of the through hole is provided on the substrate surface of the ceramic substrate. A step of providing a surface electrode that conducts to the side surface electrode, and at the same time, providing a conducting portion that conducts between adjacent surface electrodes.

(b) A step of integrally forming a resistor between surface electrodes of adjacent through holes on the ceramic substrate.

(c) A step of covering the surface of the resistor with a protective film.

(d) A step of electrolytically plating the side surface electrode and the front surface electrode using the conductive portion.

(e) A step of scribing a ceramic substrate in a direction perpendicular to the longitudinal direction of the through hole using a laser cutter and then adhering it to the film.

(f) A step of dividing into individual chips by rolling the ceramic substrate attached to the film.

(g) A step of stretching the film isotropically and separating the individual chips from each other while adhering the chips to the film.

(h) A trimming process in which the resistance value of each chip is adjusted using laser light.

(Examples) Hereinafter, preferred examples of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 is a ceramic substrate used for manufacturing a chip resistor. In the embodiment, a 96% alumina ceramic substrate having a thickness of about 0.5 mm is used. 1
Reference numeral 2 is a through hole formed in the ceramic substrate 10 in a slit shape at a predetermined interval.

A plurality of through holes 12 are formed at a predetermined interval in the width direction. A side surface electrode is integrally formed on the inner side surface of the through hole 12, and a surface electrode 16 is formed on the peripheral edge of the through hole 12 on the substrate surface, and a resistor is provided between the surface electrodes 16 of the adjacent through holes 12. It is provided.

When the side surface electrode is provided on the side surface of the through hole 12, a jig capable of maintaining the same degree of vacuum in the space of each through hole 12 is used, and one side of the board is evacuated while the conductor material is passed through from the other side of the board. It is put in the hole 12, and the conductor material is surely attached to the side surface of the through hole 12. After that, the side electrode 14 is formed by drying and firing.

At this time, a mask is placed on the ceramic substrate 10 to simultaneously form a surface electrode and an electrode for electrolytic plating as shown in FIG.

In FIG. 2, reference numeral 16 denotes a conductive portion for electrolytically plating the side surface electrode and the surface electrode. The conductive portion 16 is provided around the through hole 12 with a predetermined width, and is electrically common to the through hole 12 on the ceramic substrate 10. They are informed that they will be able to conduct electricity.

Reference numeral 18 denotes a supply electrode provided at an end portion of the ceramic substrate 10, which is an electrode connected to a plating electrode during electrolytic plating.

After the electrodes are formed as described above, the ceramic substrate 1
A resistor material is applied on one side of the substrate 0, dried and fired to form a resistor. Depending on the material, it is possible to print the resistor material after printing the conductor material and simultaneously dry and bake.

Then, for the purpose of protecting the resistor from the plating solution and the plating pretreatment solution, the resistor surface is covered with a glassy protective film.

Next, the ceramic substrate is immersed in the plating solution to perform electrolytic plating. As a result, a plating film is formed on the side surface electrode 14 and the conducting portion 16.

Next, the ceramic substrate on which the resistor, the protective film, and the plating film are formed is scribed into a large number at a narrow interval as shown by the chain double-dashed line in FIG. 2 using a laser cutter. At the time of this scribe, the laser light does not completely penetrate the ceramic substrate so that each chip is not individually separated from the ceramic substrate.

Next, the scribed ceramic substrate is attached onto the film surface coated with the adhesive, and the chips of the scribed ceramic substrate are individually divided by rolling the roller from the upper surface of the attached ceramic substrate.

Next, the film is stretched isotropically. As a result, the chips attached to the film are separated from each other at intervals while still being attached to the film. The chips thus separated become strip-shaped chip resistors as shown in FIG.

The resistance value of each chip resistor attached to the film is individually measured while it is still attached to the film, and it is trimmed to the prescribed resistance value using a laser and finally the chip resistor product. Becomes

As described above, when the side surface electrode is plated by the electrolytic plating method, there is an advantage that the plating thickness is formed uniformly and surely as compared with the conventional barrel plating method. It can be provided as a highly reliable chip resistor without the problem of being stuck. In addition, there is an advantage that a wide range of materials can be used as the side surface electrode material by performing electrolytic plating.

Further, as described above, according to the method using the laser cutter, it is possible to manufacture the chip resistor with an extremely small size of about 1 mm × 0.6 mm, which has been difficult to manufacture by the conventional method, with high shape accuracy.

In the above embodiment, when forming the side surface electrode,
Although it is formed by the printing method, other methods may of course be used, and an insertion transfer method using a jig, a coating method or the like may be used.

(Effects of the Invention) As described above, according to the method of manufacturing a chip resistor of the present invention, it is possible to obtain a small-sized, high-performance chip resistor having high shape accuracy at low cost and with good workability. It works.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a ceramic substrate used in the present invention, FIG. 2 is an explanatory view in which electrodes for electrolytic plating are provided, and FIG. 3 is an explanatory view showing an example of a chip resistor. . 10 ... Ceramic substrate, 12 ... Through hole, 14
...... Side electrodes, 16 ...... Electrodes, 18 ...... Supply electrodes, 20
...... Resistor.

Claims (1)

[Claims] 1. A method of manufacturing a chip resistor for collectively manufacturing a large number of chip resistors, characterized in that the chip resistors are manufactured in the order of the following steps (a) to (h). (a) For a ceramic substrate having slit-shaped through holes formed in parallel in a plurality of rows at regular intervals, a side surface electrode is provided on the inner surface of the through hole, and the peripheral surface of the through hole is provided on the substrate surface of the ceramic substrate. A step of providing a surface electrode that conducts to the side surface electrode, and at the same time, providing a conducting portion that conducts between adjacent surface electrodes. (b) A step of integrally forming a resistor between surface electrodes of adjacent through holes on the ceramic substrate. (c) A step of covering the surface of the resistor with a protective film. (d) A step of electrolytically plating the side surface electrode and the front surface electrode using the conductive portion. (e) A step of scribing a ceramic substrate in a direction perpendicular to the longitudinal direction of the through hole using a laser cutter and then adhering it to the film. (f) A step of dividing into individual chips by rolling the ceramic substrate attached to the film. (g) A step of stretching the film isotropically and separating the individual chips from each other while adhering the chips to the film. (h) A trimming process in which the resistance value of each chip is adjusted using laser light.