JPH09275046A - Formation of terminal electrode of electronic part and its transfer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a terminal electrode at the end surface of electronic part riding over the surface connected thereto. SOLUTION: A rubber body 21 on which a plurality of recessed grooves 22 are formed on a flat surface is provided, the recessed groove 22 of the rubber body 21 is filled with a conductive paste, the rubber body 21 is pressed toward one surface of an electronic part 24, the conductive paste is transferred simultaneously to one surface of the electronic part 24 and the surface connected thereto, and terminal electrodes are formed to one surface of the electronic part and the surface connected thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous body transfer method, and more particularly to a method for forming a terminal electrode of an electronic component.

[0002]

2. Description of the Related Art FIG. 8 shows a perspective view of an example of an electronic component.
In this electronic component, a circuit such as a coil or a capacitor is formed inside, and a terminal electrode 2 is formed on a side surface 1. The terminal electrode 2 is also formed so as to extend around the upper surface 3 and the lower surface following the side surface 1. The fact that the terminal electrode 2 is formed continuously not only on the side surface 1 but also on the upper surface 3 and the lower surface is necessary in order to increase the fixing strength with the circuit board when mounting this electronic component on the circuit board. Has been done. As a method of forming the terminal electrode 2 on this electronic component, there is a screen printing method. In this screen printing method, in the case of FIG. 8, screen printing is performed on each of the surfaces on which the terminal electrodes are formed, that is, the side surface 1, the upper surface 3, the lower surface and the other side surface facing the side surface 1.

Another method is disclosed in Japanese Patent Laid-Open No. 256256/1990.
Is disclosed in Japanese Unexamined Patent Application Publication No. 2000-205,878. This method is illustrated in FIG.
As shown in FIG. 5, a slit plate 6 having through slits 6a formed with a predetermined width and interval according to the number and position of electrodes to be formed, the slit plate 6 is placed on top, and the electrode paste bath 5 is provided inside. It has a container 7 stored therein and a pressurizing means 8 provided on the side surface side of this container 7. When the pressing plate 8a provided in this pressurizing means 8 is pushed down to press the electrode paste 5, the electrode paste 5 It has a structure in which a part is pushed out from the through slit 6a. The electronic component 4 is placed on the slit plate 6 so that the end surface 4a on which the electrode is to be formed straddles the through slit 6a, and the pressing means 8 is pressed as described above,
The liquid level of the electrode paste bath is raised so that the electrode paste 5 is raised to a certain height on the slit plate 6, and the electrode paste 2 is formed by contacting the end face 4a of the electronic component 4 and the two faces continuous with the end face 4a. It is a thing.

Another method is disclosed in Japanese Patent Laid-Open No. 6-7709.
Some of them are disclosed in Japanese Patent No. This method uses the jig shown in FIG. This jig 9 has a first groove 11 which is parallel to each other and has a width and an interval depending on the number and position of electrodes to be formed, and a length which is orthogonal to the groove 11 and is longer than the length of the first groove 11. The second groove 12 having a narrow width and a width larger than the thickness of the electronic component is formed of an elastic body. An appropriate amount of conductive paste is supplied to the second groove 12,
Pull the full width squeegee of the second groove 12 into the first groove 11
Is filled with a conductive paste, the electronic component is floated so as to be located in the center of the second groove 12, and horizontally moved as it is.
Release the pressure after applying pressure by contacting one wall, then release by applying a pressure so as to contact the other wall, apply the conductive paste to both sides continuous with the end surface of the electronic component, Further, the electronic component is lowered and pressed against the bottom of the second groove 12 in a state where it is not in contact with both walls, and the conductive paste is applied to the end face of the electronic component. As a result, the strip-shaped conductive paste is applied across the end surface of the electronic component and the surface continuous with the end surface.

[0005]

The conventional method for forming a terminal electrode has the following problems. First, according to the screen printing method, for example, in the electronic component shown in FIG. 8, there are four printing steps, each time the electronic components are aligned, the electrode paste is screen printed, the electrodes are dried, and then the It is also necessary to repeat the same steps such as aligning electronic components, screen-printing an electrode paste, and drying the electrodes. As described above, the manufacturing process is complicated, the number of steps is large, and the cost is high.

In the method described in Japanese Patent Application Laid-Open No. 2-256225 shown in FIG. 9, as described in Japanese Patent Application Laid-Open No. 6-77099, an electrode is formed by the conductive paste 5 rising from the through hole 6a. Since the wraparound part of the conductive paste is affected by the viscosity of the conductive paste and a stable shape cannot be obtained, the defective rate of the product increases and the conductive paste remains on the slit plate with through holes after the electrodes are formed. Therefore, it is necessary to remove this, and as a result, it has been pointed out that it affects work efficiency.

Further, Japanese Patent Laid-Open No. 6-77099 shown in FIG.
According to the method described in the publication, the electronic component is held in the center of the second groove of the jig shown in FIG. 10 by floating, and is moved in the horizontal direction in the floating state. Therefore, the electronic component is held with high positional accuracy. And needs to be moved. Also, in the step of applying the conductive paste to the electronic component, it is necessary to move the electronic component twice in the horizontal direction and once in the vertical direction, resulting in a large number of steps and a large cost. In view of the above, it is an object of the present invention to provide a method for easily forming a terminal electrode on an end face of an electronic component, the terminal electrode straddling a surface continuous with the end face.

[0008]

SUMMARY OF THE INVENTION According to the present invention, an elastic body having a recess formed therein, a conductive paste is filled in the recess of the elastic body, and the elastic body is pressed against one surface of the electronic component, A method of forming a terminal electrode of an electronic component, wherein a conductive paste is simultaneously transferred to the one face and at least one face connected to the one face, and a terminal electrode is formed on the one face of the electronic component and at least one face connected to the one face. Further, in the present invention, the recess is formed in a groove shape, and an elastic body having a plurality of groove-like recesses formed therein is used. It is desirable that the number of groove-shaped recesses is the same as the number of terminals of the required electronic component, but it is not necessarily the same. Silicon rubber is desirable as the elastic body, and the Shore hardness (JIS A hardness) of the silicone rubber is desirably 20-60. If the Shore hardness of the rubber exceeds 60, after pressing the electronic component, an impression of the electronic component remains on the rubber body and the conductive paste remains there, which is not preferable. On the other hand, if the Shore hardness of the rubber is less than 20, it is too soft, which is not preferable. Particularly preferred shore hardness of rubber is 40 to
50. The Shore hardness of this rubber is in an effective range even when rubber other than silicone rubber is used. Further, the present invention may be a method in which the elastic body is moved and pressed against the electronic component, or the electronic component is moved,
A method of pressing the elastic body may be used. In the present invention, the elastic body may be located above or below the electronic component in the direction of gravity, or may be located horizontally. Thus, the present invention is an elastic body (rubber body)
By utilizing the above deformation, the conductive paste filled in the elastic body is simultaneously transferred to one surface of the electronic component and the surface connected to the one surface. That is, electrodes of a predetermined shape are simultaneously formed on a plurality of surfaces. In particular, when forming terminal electrodes connected to three surfaces of an electronic component, terminal electrodes of a predetermined shape can be formed simultaneously on the three surfaces. The plane of the elastic body in which the recess is formed preferably has a width that is at least twice the width of the one surface of the electronic component in the direction in which the recess extends, and more preferably at least three times. Further, in the present invention, it is preferable that a viscosity ratio (1/100 rotation (per minute)) of the conductive paste with which the concave portion of the elastic body is filled is 3 or more. This conductive paste has a high viscosity when filled in the concave portion of the elastic body, is stationary in the concave portion, and has a low viscosity when pressed and transferred to an electronic component, and has a low viscosity. It is desirable that the robot be easy to move. Therefore, the thixotropy is high and the viscosity ratio (1/100
The rotation (per minute)) is preferably 3 or more. More preferably, it is 5 or more. It is desirable that the transferred terminal electrode of the present invention is baked and then Ni-plated and solder-plated. The conductive paste of the present invention preferably contains Ag or Cu as the main component because of its low electric resistance. However, in the case of Cu, a reducing atmosphere is required for baking or heat treatment. Further, the present invention is not limited to the method of forming the terminal electrode of the electronic component, and can be used as a method of simply transferring a substance having viscosity to a plurality of surfaces simultaneously. That is, according to one aspect of the present invention, an elastic body having a recess is formed, the recess of the elastic body is filled with a viscous body, and the elastic body is pressed against one surface of the transfer target, The viscous body is simultaneously transferred to at least one surface connected to the one surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 shows a perspective view of an embodiment according to the present invention. FIG. 2 is a perspective view of the electronic component after terminal electrode transfer.
FIG. 3 is a perspective view showing the surface of the rubber body according to the present invention in which the groove-shaped recess is formed. In this embodiment, three groove-shaped recesses 22 are formed in an elastic body 21 made of silicon rubber.
The groove-shaped recess 22 is filled with a conductive paste mainly composed of Ag. This conductive paste is filled with a dispenser and then scraped off with a squeegee 23 as shown in FIG. At this time, the scraping property was improved by scraping the squeegee 23 so that the angle of the squeegee 23 and the groove direction of the groove-shaped recess 22 were not 90 ° but slanted. This angle θ1
Was carried out at 60 °, but 15 ° to 75 ° is suitable. Further, the angle θ of the squeegee with respect to the plane of the elastic body 21
2 was done at 45 °. The electronic component 24 is positioned so that the surface 25 on which the terminal electrode is formed is the upper surface, the rubber body 21 filled with the conductive paste is lowered from above, and the rubber body 21 is pressed against the electronic component 24. Rubber body 2
The conductive paste in the groove-shaped recess 22 of No. 1 is transferred to one surface 25 of the electronic component 24 and a surface continuous with the one surface. The electronic component 24 is an electronic component using a ceramic material and has a circuit formed therein. The dimensions of this electronic component 24 are A = 1.0 mm and B = 3.2 m.
m, and the size of the elastic body 21 is
C = 50 mm and D = 10 mm were used.

Next, with the elastic body 21 facing downward, the electronic component 2
Various evaluations were made on the Shore hardness (JIS A hardness) of the silicone rubber of the elastic body 21 with 4 as the upper side. The shore hardness of the rubber and the pressing amount (the plane of the rubber before contact is 0 mm and the distance from which the electronic component is pressed) are changed, and the state of the indentation of the electronic component 24 of the elastic body 21 after the pressing is shown in Table 1. Shown in. At this time, the thickness of the elastic body is 5 mm
The width of the groove-shaped recess is 0.4 mm, the depth is 0.33 mm,
The pressing time is 3 seconds.

[0011]

[Table 1]

In Table 1, ◯ means that no indentation remained and it was good. Δ indicates that an indentation remains immediately after pressing, but disappears thereafter and is usable. ×
Indicates that the impression remains, the conductive paste accumulates on the impression, and cannot be used. As shown in Table 1, when the Shore hardness of the rubber is 20 to 60, good results are obtained, and when the rubber hardness is 70, it cannot be used.

FIG. 5 shows a perspective view of another embodiment, and FIG. 6 shows a perspective view of an electronic component to which a terminal electrode is transferred. The same parts are designated by the same reference numerals. In this embodiment, the elastic body 21 is arranged horizontally with respect to the electronic component 24, and the groove-shaped recess 22 extends vertically. Then, the elastic body 21 is pressed against the electronic component 24 from both sides to form the terminal electrodes on both sides of the electronic component 24 at once. In this example, the conductive paste was changed. Table 2 shows properties of the conductive paste. At this time, the thickness of the elastic body is 5 mm, the width of the groove-shaped recess is 0.4 mm, the depth is 0.33 mm, the pressing amount is 0.4 mm, and the pressing time is 1 second.

[0014]

[Table 2]

The viscosities shown in Table 2 are as follows: Spindle No. 1 using a Brookfield DV3 model as a rotational viscometer.
4 was used. The results of using these pastes are shown in Table 2 as evaluations. This evaluation is an evaluation taking into account the values and variations of the width and thickness of the electrodes formed on the side surfaces of the electronic component. ○ means no problem at all, △
Is slightly feasible but at a feasible level. The electrode thickness of the terminal electrode of this example is 30 μm ± 1 after drying.
It was in the range of 0 μm, and it could be carried out in the range of 15 μm ± 5 μm after baking. The width of the electrode is 0.4 mm ± 0.
The protrusion dimension of the upper and lower lands formed on the side surface of the terminal electrode is 0.35 mm.
It was ± 0.05 mm, which was a practical level. On this terminal electrode, Ni plating of about 1 to 5 μm is applied, and solder plating of about 10 μm is applied.

From each of the embodiments, as the dimension of the elastic body, as shown in FIG. 7, the dimension up to the end of the electronic component 26 and the elastic body 25, and the E dimension of 0.5 mm or more, F is preferable. The dimension is preferably 1 mm or more. of course,
The elastic body in this range needs to be flat. Therefore, the outside of the range may not be flat, and the recess may not be formed in a groove shape from end face to end face. In addition, the groove depth of the elastic body 25 was best 0.33 mm in the above embodiment. This is considered to change depending on the target electrode thickness, paste viscosity, and the like. Moreover, the pressing amount for pressing the elastic body against the electronic component is 0.4 to 0.45 mm.
Was appropriate. This is also considered to change depending on the target electrode thickness, paste viscosity, and the like. Of course, in these examples, the terminal electrode is formed by pressing the elastic body once against the electronic component. From these examples, it can be seen that the viscous material can be similarly transferred to a plurality of surfaces by using a material having another viscosity instead of the conductive paste and using another material instead of the electronic component. .

[0017]

According to the present invention, a recess having a width and a depth corresponding to an electrode is formed in at least a part of a planar elastic body, and the recess is filled with a conductive paste and then pressed against an electronic component. Thus, it is possible to simultaneously form the terminal electrodes on the predetermined side surface of the electronic component and the surface following the side surface on a plurality of concavities, and it is possible to extremely easily form the terminal electrode of the electronic component. Moreover, the same effect can be obtained even if it is other than an electronic component or a conductive paste.

[Brief description of drawings]

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

FIG. 2 is a perspective view of an electronic component after terminal electrode transfer according to one embodiment of the present invention.

FIG. 3 is a perspective view of an elastic body according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of an embodiment according to the present invention.

FIG. 5 is a perspective view of another embodiment according to the present invention.

FIG. 6 is a perspective view of an electronic component after terminal electrode transfer according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram of an elastic body according to an embodiment of the present invention.

FIG. 8 is a perspective view of an electronic component.

FIG. 9 is a structural diagram of a conventional example.

FIG. 10 is a perspective view of another conventional example.

[Explanation of symbols]

 21 Elastic Body 22 Groove-Shaped Recess 23 Squeegee 24 Electronic Component

Front page continued (72) Inventor Makoto Ota 33-12 Minamieicho, Tottori City, Tottori Prefecture Hitachi Metals Co., Ltd. Tottori Factory

Claims (7)

[Claims] 1. An elastic body having a concave portion formed therein, the concave portion of the elastic body being filled with a conductive paste, the elastic body being pressed against one surface of an electronic component, and being connected to the one surface of the electronic component and the one surface. A method of forming a terminal electrode for an electronic component, comprising simultaneously transferring a conductive paste onto one face and forming a terminal electrode on the one face of the electronic component and at least one face connected to the one face. 2. The method of forming a terminal electrode of an electronic component according to claim 1, wherein the recess has a groove shape and a plurality of recesses are formed. 3. The elastic body is silicone rubber, and the Shore hardness (JIS A hardness) of the silicone rubber is 20.
The method for forming a terminal electrode of an electronic component according to claim 1, wherein: 4. The method of forming a terminal electrode of an electronic component according to claim 1, wherein the elastic body is located above or below the electronic component in the gravity direction. 5. The method of forming a terminal electrode of an electronic component according to claim 1, wherein the elastic body is positioned in a horizontal direction with respect to the electronic component. 6. The viscosity ratio (ratio of 1 rotation / minute and 100 rotations / minute) of the conductive paste filled in the concave portion of the elastic body is 3 or more. Of forming a terminal electrode of an electronic component. 7. An elastic body having a concave portion formed therein, the concave portion of the elastic body being filled with a viscous body, and the elastic body being pressed against one surface of the transferred material, and being connected to the one surface of the transferred material and the one surface. A transfer method comprising simultaneously transferring a viscous material onto at least one surface.