JPH06244010A - Protection film formation method for chip-like circuit components - Google Patents

Abstract

PURPOSE:To make it possible to coat efficiently a square-shaped chip component on a specified side of the square-shaped chip component and provide a protection film formation method to square-shaped chip components which are suitable to automation. CONSTITUTION:A process which eliminates a protection film 3 for such parts that form outside electrodes 7 on the surface of a chip-like raw material 1 is to cover the parts forming the outside electrodes 7 on the surface of the raw material 1 preliminarily with resists 2 and to eliminate this protection film 3 and the resists 2 from the surface of the raw material 1 after having formed the protection film 3 on the whole surfaces of the raw material 1 from the upper part of the resists 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when manufacturing a circuit component such as a thermistor, a capacitor, an inductor or a resistor, forms a protective film on a predetermined surface portion other than a portion of an element body where an external electrode is formed. Regarding the method.

[0002]

2. Description of the Related Art In a chip type electronic component such as a chip type thermistor or a multilayer chip type capacitor, terminal electrodes are formed on both ends of a cubic element body. This terminal electrode is formed by applying a conductive paste to both ends of a body made of ceramic or the like, drying it, baking it, and then plating it. Further, for example, when plating both ends of a rectangular chip component, a protective film such as a glass coat or a resin coat is preliminarily provided on the exposed central portion of the element body in order to prevent erosion or extension of the element body by the plating solution. After applying, plating is performed.

Conventionally, such a protective film is obtained by cutting a ceramic laminated sheet and cutting it into individual rectangular chip-shaped elements, and then removing the resin paste on the surface of the element other than the end surface where the external electrodes are to be formed. It was formed by applying a paint such as glass or glass paste and baking it.

As another method, Japanese Patent Laid-Open No. 3-250
As disclosed in Japanese Patent No. 603, the coating material such as glass paste is applied to both main surfaces of the ceramic laminated sheet, and after baking this, the ceramic laminated sheet is cut into strips, and the cut surface has glass paste or the like. There is proposed a method of applying the coating composition, baking, and cutting into individual rectangular chip-shaped element bodies in a direction perpendicular to the cut surface obtained by the above-described cutting.

[0005]

However, in the method of forming the protective film on the rectangular chip-shaped element body according to the above-mentioned conventional technique, the coating is individually applied to a predetermined surface of the small rectangular chip-shaped element body, Since it has to be baked, it is difficult to automate the painting, and more labor must be applied to the painting. Therefore, work efficiency is poor.

Further, since the corners of the rectangular chip-shaped element are likely to be chipped, it is necessary to carry out a polishing step of cutting the rectangular chips into a rectangular chip and then rounding the corners. However, JP-A-3-
In the method of Japanese Patent No. 250603, since a glass paste is applied and then cut out into a rectangular chip-shaped element body, a polishing step for rounding the corners becomes impossible, and the corners remain square, so that they are in the middle of manufacturing. There is a problem that a corner may be chipped or a chip that was not chipped during manufacturing may be chipped when it is mounted on a circuit board.

In view of the above-mentioned problems of the prior art, the present invention provides a method of forming a protective film on a predetermined surface of a rectangular chip component efficiently, and a method of forming a protective film on a rectangular chip component suitable for automation. The purpose is to

[0008]

That is, according to the present invention,
In order to achieve the above-mentioned object, the protective film 3 is formed on a predetermined portion of the surface of the chip-shaped element body 1 except a portion where the external electrode 7 is formed.
In the method for forming the same, the method includes the step of forming the protective film 3 on the entire surface of the chip-shaped element body 1 and the step of removing the protective film 3 on the surface of the element body 1 where the external electrodes 7 are formed. Provided is a method for forming a protective film for a characteristic chip-shaped circuit component.

In this case, in the step of removing the protective film 3 on the surface of the element body 1 where the external electrodes 7 and 7 are formed, the portion of the surface of the element body 1 where the external electrodes 7 and 7 are to be formed is previously prepared. Cover with the resists 2 and 2, and then from above the resists 2 and 2, the body 1
After the protective film 3 is formed on the entire surface of, the protective film 3 can be removed together with the resist 2 from the surface of the element body 1.

[0010]

In the method for forming a protective film for a chip-shaped circuit component according to the present invention, the protective film 3 is formed on the entire surface of the chip-shaped element body 1, and the unnecessary portion of the protective film 3 is removed.
The protective film 3 can be formed only on a predetermined portion of the surface of the.

The portions of the surface of the element body 1 where the external electrodes 7, 7 are to be formed are covered with resists 2 and 2 in advance, and the protective film 3 is formed on the entire surface of the element body 1 from above the resists 2 and 2. After that, if this protective film 3 is removed from the surface of the element body 1 together with the resist 2, the element body 1 is not damaged and can be easily formed only from the portion where the external electrodes 7, 7 are to be formed. Moreover, the protective film 3 can be removed.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. First, as shown in FIG.
A chip-shaped element body 1 is prepared. The element body 1 is, for example, an element body such as a chip type thermistor, a monolithic ceramic capacitor or a monolithic ceramic inductor, and has a rectangular chip shape made of a cubic ceramic laminate.

Next, as shown in FIG. 1B, the resist 2 is formed on the end face of the element body 1 by means of a dipping method or the like.
2. Apply and cure. In this state, the element body 1 is put into a vacuum vapor deposition apparatus or a chemical vapor deposition apparatus, and a protective film material is vapor-deposited on the entire surface thereof to form a protective film 3, as shown in FIG. The protective film 3 is made of, for example, an inorganic material such as amorphous aluminum oxide or SiO _2, or an organic material such as a synthetic resin, and has a resistance to the plating solution and an insulating property. Next, as shown in FIG. 1D, the resists 2 and 2 on both ends of the element body 1 are removed. As a result, the protective film 3 on the end surface of the element body 1 is also removed together with the resists 2 and 2, and the protective film 3 is left only on both side surfaces and upper and lower surfaces of the element body 1.

External electrodes 7 are formed on both ends of the element body 1 on which the protective film 3 is formed in this manner, where the protective film 3 is not provided.
7 is provided by, for example, the following method. First, a conductive paste such as a silver paste is applied to both ends of the element body 1 not covered with the protective film 3 by a dipping method or the like,
This is baked to form the conductor films 4 and 4. Next, nickel and solder or tin or the like are sequentially plated on the conductor film 4 to form conductor films 5, 5, 6, and 6. This allows
A chip-shaped circuit component having the external electrodes 7, 7 on both ends is completed.

Next, referring to FIG. 2, a second embodiment of the present invention will be described. This second embodiment does not apply the resist as described above. That is, as shown in FIG. 2 (a), an element body 1 is prepared, and this element body 1 is placed in a vacuum vapor deposition apparatus, and as shown in FIG. 2 (b), its entire surface is resistant to plating. The material having is evaporated to form the protective film 3. Next, as shown in FIG. 2C, both end portions of the element body 1 to which the protective film 3 is applied are to be polished or the outer electrodes 7 are to be formed, or the protective film 3 is etched. The protective film 3 is removed to expose both ends of the element body 1.

External electrodes 7, 7 are formed on the end portions of the element body 1 on which the protective film 3 is formed in this manner, where the protective film 3 is not provided.
Is provided in the same manner as the method described above. That is, as shown in FIGS. 22E to 22F, the conductor films 4, 5 and 6 are sequentially formed on both ends of the element body 1 to form the external electrodes 7 and 7.

[0017]

As described above, according to the present invention, since the protective film 3 is formed on the entire surface of the chip-shaped element body 1 and the unnecessary portion of the protective film 3 is removed, the surface of the element body 1 is removed. It becomes possible to form the protective film 3 only on a predetermined portion of the rectangular chip component, and the protective film can be efficiently formed on the predetermined surface of the rectangular chip component, and a protective film forming method suitable for automation can be obtained. To be

The portions of the element body 1 where the external electrodes 7, 7 are formed are covered with resists 2, 2 in advance, and the resists 2, 2 are formed.
If the protective film 3 is formed on the entire surface of the element body 1 from above and then the protective film 3 is removed from the surface of the element body 1 together with the resist 2, the element body 1 is not damaged. Since the protective film 3 can be easily removed only from the portions where the external electrodes 7, 7 are to be formed, more efficient and high productivity can be obtained.

[Brief description of drawings]

FIG. 1 is a side view in which a state of a work in each step in a method of forming a protective film for a chip-shaped circuit component according to a first embodiment of the present invention is shown in section except for an element body.

FIG. 2 is a side view in which a state of a work in each step in a method of forming a protective film on a chip-shaped circuit component according to a second embodiment of the present invention is shown in cross section except for an element body.

[Explanation of symbols]

 1 Element 2 Resist 3 Protective film 4 Conductor film 5 Conductor film 6 Conductor film 7 External electrode

Claims (2)

[Reference number] 0040954-01 [Claims] 1. A protective film (3) is provided on a predetermined portion of the surface of a chip-shaped element body (1) except a portion where an external electrode (7) is formed.
In the method for forming a substrate, a step of forming a protective film (3) on the entire surface of the chip-shaped element body (1) and a portion of the surface of the element body (1) where the external electrode (7) is formed are formed. ) Is removed, the protective film formation method of the chip-shaped circuit component characterized by the above-mentioned. 2. The process according to claim 1, wherein the step of removing the protective film (3) at the portion where the external electrodes (7), (7) are formed on the element body (1) is performed on the surface of the element body (1). External electrode (7),
The portion forming (7) is covered with resists (2) and (2) in advance, and the element body (1) is placed on the resists (2) and (2).
Of the chip-shaped circuit component, which is a step of forming a protective film (3) on the entire surface of and then removing the protective film (3) together with the resist (2) from the surface of the element body (1). Film forming method.