JP2001269616A - External electrode coating method for electronic components - Google Patents

Abstract

(57) [Summary] [Problem] To increase the length by which an external electrode goes around a chip surface without lowering the application accuracy of a conductive paste, and to sufficiently secure the bonding strength to a wiring board. A conductive paste for external electrodes is provided on the surface.
Are arranged, and a rectangular electronic component substrate 10 is supplied between the application rollers 1 and 1 ', and the end face of the electronic component substrate 10 and the In a method for coating an external electrode of an electronic component, a plurality of external electrodes 4a are formed at both ends of the electronic component substrate 10 by bringing the conductive pastes 4 and 4 'into contact with the ends of both main surfaces adjacent to the end surface. After the conductive pastes 4 and 4 ′ come into contact with both ends of the electronic component substrate 10, the electronic component substrate 10 is supplied in a direction in which the electronic component substrate 10 is supplied to the application rollers 1 and 1 ′.
And / or vibrating the application rollers 1, 1 '.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating external electrodes of chip-type electronic components such as capacitors, inductors and resistors.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and more sophisticated, there has been a growing demand for electronic components installed in the electronic devices to be smaller, more multiplexed, thinner, and compatible with high frequencies. I have. In particular, information communication and personal computer terminal devices are inevitably portable, and are becoming smaller and lighter year by year, increasing the need for high-density mounting of electronic components. Many electronic components 20 are used.

The external electrode 4a of the multiple-type electronic component 20 has, for example, an end portion of the electronic component 20 shown in FIG. It is necessary to form a plurality of external electrodes 4a over the other main surface 5c via 5a. For this reason, the screen printing has been used because it is difficult to form the conductive paste by the conventional method of dipping the conductive paste. However, since the conductive paste is applied to each of the surfaces 5b, 5a, and 5c by screen printing to form the external electrodes 4a, the number of application times increases, and the cost increases in mass production. there were.

As a method for solving the above problem, FIG.
As shown in FIG. 7, at least two of the conductive pastes 4 and 4 ′ having a plurality of coated portions on the surface of which the conductive pastes 4 and 4 ′ for the external electrodes 4 a are adhered.
The two application rollers 1, 1 'are arranged substantially in parallel, and
The electronic component substrate 10 is supplied between the application rollers 1 and 1 ′, and the entire end surface of the electronic component substrate 10 is brought into contact with the conductive pastes 4 and 4 ′, so that a plurality of external components are provided at both ends of the electronic component substrate 10. A method for applying an external electrode to an electronic component forming the electrode 4a has been proposed. Here, FIG. 7 is an external perspective view of the external electrode coating method of the above method. FIG. 3 is an external perspective view in which the electronic component substrate 10 is in contact with the application roller 1.

To explain the configuration for carrying out the above method, the elastic applying roller 1 rotates counterclockwise as indicated by an arrow R, and the applying roller 1 'rotates clockwise as indicated by an arrow R' in synchronization therewith. Is to rotate. Each application roller 1, 1
The width and pitch (arrangement interval) of the protrusions (coating portions) formed on the outer peripheral surface of ′ correspond to the width and arrangement interval of the external electrodes to be formed on the electronic component substrate 10 side. Dispensers 3, 3 'for supplying conductor pastes 4, 4' are arranged above the application rollers 1, 1 ', and upper blades 2, 2' are provided above the application rollers 1, 1 '. The conductive pastes 4 and 4 ′ are arranged so as to be in contact with the convex portions (applied portions) on the outer circumference of the application rollers 1 and 1 ′, and the conductive pastes 4 and 4 ′ are stored above the upper blades 2 and 2 ′.

Next, a method of applying the conductor pastes 4 and 4 'will be described. First, the conductor pastes 4 and 4 ′ are supplied from the dispenser 3 to the convex portions (application portions) on the outer periphery of the left and right application rollers 1 and 1 ′ according to the rotation of the application rollers 1 and 1 ′. Since the excess conductive paste 4 and 4 'remaining in''are scraped off, the thickness of the conductive paste 4 and 4' on each of the application rollers 1 and 1 'becomes uniform.
Thereafter, by passing the electronic component substrate 10 between the rotating left and right coating rollers 1 and 1 ', each convex portion (coating portion)
The conductor pastes 4 and 4 ′ attached to the electronic component base material 10 are applied to a plurality of locations at both end portions of the electronic component substrate 10. That is, at this time, since the end of the component passes through the conductor pastes 4 and 4 ', the conductor pastes 4 and 4 shown in FIG. 6 extend from one end face 5a of the electronic component base 10 to the adjacent faces 5b and 5c.
'Can be applied, and an electronic component 20 to which a plurality of external electrodes adhere as shown in FIG. 5 can be obtained. That is, since the external electrodes 4a over two or three surfaces can be simultaneously formed by one application, and the conductive pastes 4 and 4 'can be applied continuously,
Productivity is improved.

[0007]

Here, the electronic component 20
Is soldered to the wiring board, and one end face 5 of the electronic component substrate 10 is required to secure the fixing strength to the wiring board.
It is desirable that the area of the part that goes around from a to the adjacent surfaces 5b and 5c be large. Generally, it is represented by the P dimension in FIG. 6, and the P dimension of the external electrode 4a is required to be 0.1 mm or more. If the P dimension is less than 0.1 mm, reliable solder connection will be insufficient at the time of mounting, and if it is used for a wiring board of a portable terminal such as a mobile phone, the terminal may fall. There is a problem that the risk of dropping the electronic component 20 due to an impact increases.

However, even if the P dimension is to be lengthened, the conductive pastes 4 and 4 'are adhered to the adhering portions formed on the outer peripheral surfaces of the two elastic applying rollers 1 and 1'.電子 soak the electronic component substrate 10 in the
The surface 5 adjacent to the surface 5a of the electronic component substrate 10
In the method of applying the external electrodes to the electronic components, the conductive pastes 4 and 4 'are applied so as to cover the conductive pastes 4 and 4' as shown in FIG. 2B. There was a problem that the thickness could not be greater than 't. To solve this problem, it is conceivable to increase the thickness t of the conductor pastes 4 and 4 '. However, if the thickness t of the conductor pastes 4 and 4' is increased, the conductor pastes 4 and 4 ''Dripped, making it difficult to apply a plurality of external electrodes 4a at once with high accuracy, and it was difficult to stably obtain a desired P dimension.

The present invention has been achieved in view of the above-mentioned problems, and has as its object to provide an external component of an electronic component that can obtain a sufficient P dimension even when a plurality of external electrodes 4a of the electronic component 20 are formed. It is intended to provide an electrode coating method.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a coating roller having a plurality of coating portions on the surface of which a conductor paste for an external electrode is adhered. The electronic component base is supplied in a direction substantially orthogonal to the arrangement direction of the parts, and the conductive paste is brought into contact with an end surface of the electronic component base and ends of both main surfaces adjacent to the end surface. In the method for applying an external electrode to an electronic component, the method comprising: applying a plurality of external electrodes to an end of the substrate; and supplying the electronic component substrate to the application unit after the conductive paste contacts the end of the electronic component. To
A method for applying an external electrode to an electronic component, comprising vibrating the electronic component substrate and / or the application roller.

According to the structure of the present invention, after the conductor paste comes into contact with the end of the electronic component substrate, the electronic component substrate and / or the application roller are moved in a direction in which the electronic component substrate is supplied to the application section. Can be applied while scraping off the conductive paste at the application portion at the end of the electronic component substrate, thereby increasing the P dimension of the external electrode to be greater than the thickness of the conductive paste attached to the application roller. be able to. As a result, it is possible to improve the bonding strength of all the external electrodes of the multiple electronic component in which a plurality of external electrodes are formed at one time. Conversely, a desired P dimension can be obtained even if the thickness of the conductive paste attached to the application roller is reduced.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for applying an external electrode to an electronic component according to the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view of an external electrode coating device A of the present invention. FIG.
FIG. 2 is an external perspective view in which an electronic component substrate 10 is in contact with application rollers 1 and 1 ′. In the figure, external electrode coating device A
Consists of application rollers 1, 1 ', blades 2, 2', dispensers 3, 3 ', and conductor pastes 4, 4'.

The outer peripheral surfaces of the application rollers 1 and 1 'have a plurality of convex portions (application portions) 1a which become application portions in the axial direction.
The width and pitch (arrangement interval) of the convex portions (application portions) 1a correspond to the width and arrangement interval of the external electrodes 4a to be formed on the electronic component substrate 10 side. The material of the application rollers 1 and 1 ′ is not such as to damage the electronic component base, and if the shape of the convex portion or the concave portion can be maintained, not only metal but also rubber,
A flexible material such as silicon may be used.

In FIG. 1, two application rollers 1, 1 '
Are arranged substantially in parallel, the application roller 1 rotates counterclockwise as indicated by an arrow R, and the application roller 1 ′ rotates clockwise as indicated by an arrow R ′ in synchronization therewith. is there.

The conductive pastes 4 and 4 'are attached to the convex portions (coating portions) of the application rollers 1 and 1', and the electronic component substrate 10 is supplied between the application rollers 1 and 1 '. By bringing the entire end face of the component base 10 into contact with the conductive pastes 4 and 4 ′, the external electrodes 4 are attached to both ends of the electronic component base 10.
a is formed. Here, the diameter of the application rollers 1, 1 'is changed according to the shape and size of the electronic component 20, and the rotation speed of the application rollers 1, 1' is determined by the properties of the electrode material such as the conductive paste 4, 4 '. It shall be variable.

The conductive pastes 4 and 4 'are made of a noble metal such as silver or palladium, or a base metal such as nickel or copper.
Alternatively, a low-melting-point material such as glass is mixed therein to improve the adhesion strength of the electronic component 20 to ceramics. Further, although not shown, there is provided a means for regularly moving the electronic component substrate 10 to an intermediate application position between the left and right application rollers 1, 1 '.

After the conductor pastes 4 and 4 'come into contact with both ends of the electronic component substrate 10, the electronic component substrate 10 is applied to the application rollers 1 and 1' or the application rollers 1 and 1 '.
The electronic component base 1 is vibrated with respect to the electronic component base 10 in a direction in which the electronic component base 10 is supplied between the application rollers 1 and 1 ′. Here, the direction in which the electronic component substrate 10 is supplied is a direction substantially orthogonal to the arrangement direction of the conductor pastes 4 and 4 'in which a plurality of application portions are arranged. The vibration direction of the component substrate 10 is indicated by S, and the vibration directions of the application rollers 1 and 1 'are indicated by M and M', respectively. In the present invention, either the application roller 1, 1 'or the electronic component substrate 10 may be vibrated, or both the electronic component substrate 10 and the application roller 1, 1' may be relatively vibrated simultaneously.

Next, a method of attaching the conductive pastes 4 and 4 'to the convex portions (application portions) of the application rollers 1 and 1' will be described. A dispenser 3 for supplying the conductive pastes 4 and 4 'is disposed above the application rollers 1 and 1', and a blade 2 is disposed on the outer periphery of the application rollers 1 and 1 'above the application rollers 1 and 1'. The upper side of the upper blade 2 is a pool of the conductive pastes 4 and 4 '.

The blade 2 is required to have a constant distance from the convex portion (applied portion) and to stably adhere and form the electrode material. Therefore, a material having excellent wear resistance is selected. As the material, for example, metal, plastic, glass, ceramics and the like are used.

First, the rotation R of each of the application rollers 1, 1 'is applied to a convex portion (application section) 1a on the outer periphery of the left and right application rollers 1, 1'.
Conductor paste 4, 4 from dispenser 3 according to R '
Are supplied, and the excess conductive paste 4, 4 ′ remaining by the upper blade 2 is scraped off.
The thickness t of the conductor paste on 1 'is made uniform. That is,
The conductor paste thickness t is determined by the distance between the blade 2 and the application roller 1 and between the blade 2 'and the application roller 1'.

Next, the convex portion (coating portion) 1a on the outer periphery of the coating rollers 1, 1 'is supplied to a position facing the electronic component substrate 10 in the middle between the left and right coating rollers 1, 1'.
An electronic component base 1 is provided between the rotating left and right coating rollers 1 and 1 '.
As a result, the conductor pastes 4 and 4 ′ attached to the respective convex portions (application portions) 1 a are applied to both ends of the electronic component substrate 10 at a plurality of locations. Here, after the conductive pastes 4 and 4 ′ come into contact with both ends of the electronic component substrate 10, the electronic component substrate 10 (vibration direction S) and / or the application rollers 1, 1 ′ (vibration directions M and M ′) are Electronic component base 1
0 vibrates in the direction supplied between the application rollers 1 and 1 '. At this time, since the end portions of the components pass through the conductor pastes 4 and 4 ', the conductor pastes 4 and 4' are applied so as to extend from one end surface 5a of the electronic component base 10 to the adjacent surfaces 5b and 5c in FIG. As a result, an electronic component 20 having a plurality of substantially U-shaped external electrodes 4a having electrode portions extending from the end surfaces 5a on both sides of the electronic component substrate 10 to the adjacent surfaces 5b and 5c is obtained. Here, after the conductive pastes 4 and 4 ′ come into contact with both ends of the electronic component substrate 10,
As shown in FIG. 2A, the electronic component base 10 and / or the application rollers 1, 1 'are vibrated in a direction in which the electronic component base 10 is supplied between the application rollers 1, 1'. Will scrape the conductive pastes 4 and 4 'on the application roller 1, and the P dimension of the electronic component 20 will be greater than or equal to the thickness t of the conductive pastes 4 and 4' attached to the attachment portion 1a. Conversely, since the thickness t of the conductor pastes 4 and 4 'to be attached to the attachment portions in order to obtain a certain P dimension can be small, accurate application is possible.

For this reason, the P dimension can be increased without lowering the coating accuracy, and the fixing strength to the wiring board can be ensured. That is, the mounting of the electronic component 20 can be more stably performed with good reproducibility. In order to secure the fixing strength with the wiring board, the fixing strength of the external electrode 4a is desirably 2.0 kg or more, and the P dimension is desirably 0.1 mm or more.

In this embodiment, the conductive pastes 4 and 4 'are applied to the convex portions (application portions) 1a of the application roller 1. However, as shown in FIG.
The conductor pastes 4 and 4 'may be adhered to the metal. In this case, as shown in FIG. 4, using a blade 2 having a flat scraping surface, the conductive pastes 4 and 4 ′ enter only the concave portion (application portion) 1 b of the application roller 1, and the convex portion 1 a of the application roller 1. So that no conductive paste remains. Then, the electronic component substrate 10 is pressed against the convex portion 1a of the application roller so that only the conductor pastes 4 and 4 'that have entered the concave portion (application portion) 1b of the application roller are formed on the end surface of the electronic component substrate 10. I do.

An elastic body is used for the convex portion (coating portion) 1a of the coating roller 1 in FIG. 3 or the concave portion (coating portion) 1b of the coating roller 1 in FIG. The convex portion (application portion) 1a or the concave portion (application portion) 1
By making b concave, it is possible to more effectively apply the conductor pastes 4 and 4 ′ so as to extend from one surface of the electronic component substrate 10 to the adjacent surface. Alternatively, when the electronic component substrate 10 hits, the application roller 1
The conductor pastes 4 and 4 ′ can be more effectively applied by performing the operation of causing the 1 ′ to approach and separate from each other. Note that these are also suitable for the case where the conductive pastes 4 and 4 'are adhered to the convex portions (application portions) 1a of the application roller 1 as shown in FIG. 3, but as shown in FIG. This is particularly suitable when the conductive pastes 4 and 4 'are to be attached to the one concave portion (application portion) 1b.

A plurality of electronic component bases 10 are arranged along the outer peripheral surface of one application roller 1 in a direction in which the external electrodes 4a are arranged.
The external electrode 4a may be simultaneously applied to the substrate.
At this time, by using the blade 2 for each electronic component substrate 10, even if the type of the component is different, it can be applied simultaneously. Thereby, productivity can be further improved.

[0026]

EXAMPLES Specific examples will be described in detail. As shown in FIG. 3, a rubber cylindrical application roller 1 and a blade
3216 type chip capacitor (1.0 mm thick) using Ag paste as conductor 2, conductor paste 4, 4 '
The external electrodes 4a were applied to four locations on one side (total of eight locations). In this case, the thickness t of the conductive paste applied on the application roller 1 was 0.1 mm.

Table 1 shows the results of confirming the P dimension when the application roller 1 and the chip capacitor 10 are vertically oscillated by 0.5 mm to 2.0 mm and the fixing strength when mounted on a wiring board.

[0028]

[Table 1]

As shown in Table 1, when the reciprocating vibration amount was 0 mm, the P dimension was as small as 0.08 mm. When the reciprocating vibration amount is 0.5 mm, the P dimension is 1.0 mm or more and the fixing strength is less than 2.0 kg when either the application roller 1 or the electronic component substrate 10 is vibrated. Was. However, when the reciprocating vibration amount was 1.0 mm or more, the fixing strength became 2.0 kg or more regardless of whether the application roller 1 or the electronic component substrate 10 was vibrated. Thus, it can be seen that the vertical vibration amount of the application roller 1 or the electronic component substrate 10 is 1 mm or more in order to stably secure the fixing strength to the wiring board. When the application rollers 1 and 1 ′ vibrate relative to the electronic component substrate 10 (vibration directions M and M ′,
M ′) and when the electronic component substrate 10 vibrates with respect to the application rollers 1 and 1 ′ (vibration direction S), the P dimension does not change, so that the adhesion strength does not change. Note that the upper limit of the vertical vibration amount depends on the size of the application roller 1. That is, in general, the larger the application roller 1 is, the larger the movable range is.

[0030]

According to the structure of the present invention, after the conductive paste comes into contact with both ends of the electronic component substrate, the electronic component substrate and / or the application roller are vibrated in the direction in which the electronic component substrate is supplied to the application roller. It is possible to apply while scraping the conductive paste adhered to the application portion at the end of the electronic component base, thereby making the P dimension of the external electrode larger than the thickness of the conductive paste adhered to the application roller. it can. As a result, it is possible to improve the bonding strength of all the external electrodes of the multiple electronic component in which a plurality of external electrodes are formed at one time. Conversely, a desired P dimension can be obtained even if the thickness of the conductive paste attached to the application roller is reduced. As described above, it is possible to provide a multiple-type electronic component capable of efficiently securing the fixing strength to the wiring board with good reproducibility.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an external electrode coating device used in the present invention.

FIG. 2 is a diagram for explaining the difference between the present invention and an external electrode coating device used in a conventional example, wherein (a) is the present invention,
(B) shows a conventional example.

FIG. 3 is an external perspective view of an external electrode coating device used in the present invention, in which an external electrode is formed by bringing an electronic component substrate into contact with a coating roller.

FIG. 4 is an external perspective view of an external electrode coating device according to another embodiment used in the present invention.

FIG. 5 is an external perspective view of the multiple electronic component after an external electrode is applied.

FIG. 6 is an enlarged explanatory view of a chip end;

FIG. 7 is an external perspective view of a conventionally used external electrode coating apparatus.

[Explanation of symbols]

 1 coating roller 1a convex portion 1b concave portion 2 blade 3 dispenser 4 conductive paste 4a external electrode 5a: End surface of laminate 5b, 5c: Main surface of laminate 10: Electronic component substrate 20: Multiple electronic component R: Application roller rotation direction S: Tip longitudinal vibration direction M ································ P dimension

Claims (1)

[Claims] 1. An application roller having a plurality of application sections on a surface of which a conductor paste for an external electrode adheres is arranged, and an electronic component substrate is supplied in a direction substantially orthogonal to the arrangement direction of the application sections. In addition, an electronic component formed by forming a plurality of external electrodes at the end of the electronic component base by bringing the conductive paste into contact with an end surface of the electronic component base and ends of both main surfaces adjacent to the end surface. In the external electrode coating method, after the conductive paste contacts an end of the electronic component base, the electronic component base and / or the application roller are vibrated in a direction in which the electronic component base is supplied to the application unit. Characteristic method of applying external electrodes to electronic components.