JPS6142903A - Method of forming sheath material of electronic part - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of forming a sheathing material for an electronic component, and more particularly to a method of forming a sheathing material on an element to which a lead wire is attached, for example.

(Prior art) Conventionally, the method for forming the exterior material of this type of electronic component is as follows:
There was a method using dipping. In this method, as shown in FIG. 7, the element 14 to which the lead wire 16 is attached is immersed in paint 18a, which is the material of the exterior material, and then pulled up.

(Problems to be Solved by the Invention) In the conventional dipping method, the paint 18a is
6, the sheathing material 18 is formed up to the part of the lead wire 16 in the part shown by dimension A in FIG. When such an electronic component is attached to, for example, a printed circuit board, the part 19 of the electronic component gets inserted into the hole of the printed circuit board 30, as shown in FIG.
It will interfere with soldering. This disadvantage becomes more noticeable when the printed circuit board is thin.

Therefore, a method can be considered in which the lead wires are coated in advance with something like paraffin that repels the paint of the exterior material, and then dipped, but even with this method, the processing is difficult and complete, and the 4X 7. (won.

Therefore, the main object of the present invention is to provide a method for forming an exterior material for an electronic component in which "sag" or "parting" of the exterior material is not formed.

(Means for Solving the Problems) The present invention is a method of forming an exterior material for an electronic component, in which the exterior material is formed by a nozzle that sprays paint by vibration of a vibrator.

(Operation) The element to which the lead wire is attached and the nozzle are brought to corresponding positions, and paint is ejected from the nozzle to apply the paint to the surface of the element to form an exterior material.

(Effect of the invention) According to this invention, the "sagging" or "parting" of the exterior material
Since almost no is formed, soldering defects do not occur when electronic components are attached to, for example, a printed circuit board. Furthermore, since the exterior material can be formed while the lead wires of the elements are held and transported with, for example, a carrier tape, continuous processing becomes possible. Furthermore, since there is no need to store the paint for dipping the element in a container, there is no need to manage the level of the paint (liquid level). Furthermore, since no container is used, the device can be made smaller and its installation area can be reduced.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIG. 1 is a front view showing an embodiment of the present invention. Second
The figure is a sectional view of a main part taken along line nn in FIG. 1.

Holes 12 for tape feeding are formed in the carrier tape 10 at predetermined intervals in its longitudinal direction. A lead wire 16 is held between each hole 12 of this carrier tape 10. The lower part of this lead wire 16 is attached to (the electrode of) the element 14 of an electronic component such as a capacitor. Therefore, by transporting the carrier tape 10 in the direction shown by arrow B in FIG. 1, each element 14 can be transported in the direction shown by arrow B in FIG.

A coating device 20 is provided at a position corresponding to the element 14 held on the carrier tape 10.

This coating device 20 is for coating the surface of the element 14 with a coating material 18a, such as a thermosetting resin such as epoxy or phenol, which is the material of the exterior material 18, and as shown in FIG. It includes a first spout 22 and a second spout 24 .

The first ejection part 22 is disposed on one main surface side of the element 14 in order to spray paint 18a onto one main surface of the element 14.
The element 14 is disposed on the other main surface side of the element 14 in order to spray paint 18a onto the other main surface of the element 14.

If the outer diameter of the element 14 is, for example, eight fins, each of the first ejection part 22 and the second ejection part 24 includes, for example, eight nozzles 22a and eight nozzles 24a arranged in one row.

As shown in FIG. 2, each nozzle 22a and 2
The tip of 4a is directed toward the element 14 side. Also,
The eight nozzles 22a and 24a are arranged in a row in a direction perpendicular to or intersecting the direction of transport of the element 14, and the length from one end of the row of these nozzles 22a and 24a to the other end is equal to the length of the element 14. 14, approximately corresponds to the length from the top end to the bottom end.

Note that only six of the nozzles 2, 2a and 24a are shown in FIG. 1 to simplify the drawing.
Only four are shown in FIG.

One of these nozzles is shown on behalf of the others in FIG. The diameter of the nozzle 22a is appropriately determined depending on the size of the element 14 and the number of nozzles arranged, and in this embodiment, it is, for example, 0.1 mm to 0.5 mm. A vibrator, such as a piezoelectric vibrator 26, is provided inside the nozzle 22a facing the tip (spout opening) of the nozzle 22a.
is provided. The piezoelectric vibrator 26 is, for example, an ultrasonic vibrator that vibrates in a bending mode, and its vibration causes the paint 18a in the nozzle 22a to generate ultrasonic vibrations, causing the paint 18a to move from the tip of the nozzle 22a to the third A mist is ejected in the direction shown by arrow C in the figure. These paint particles (
The size of the liquid Wa) depends on the period or frequency of the ultrasonic vibration,
It is determined depending on the nozzle diameter and the viscosity of the paint 18a,
The viscosity of the paint 18a is, for example, 1000 cps or less.

The atomized paint tea can be ejected from the tip of the nozzle 22a in an amount of approximately 3 to 10 fl.

In the above-described embodiment, the piezoelectric vibrator 26 was placed at a position corresponding to the ejection port of the nozzle 22a, as shown in FIG. However, the piezoelectric sensor 26 is not connected to the nozzle 2, for example.
It can be provided at any arbitrary position such as the side near the spout 2a.

In such a configuration, the carrier tape 10, that is, the elements 14 held thereon, is transferred in the direction shown by arrow B in FIG. Paint 18a can be sequentially applied to the surface. The ejection time for one element may be extremely short, for example, from 1 second to several seconds,
The paint 18a can be sufficiently applied to the surface. The applied paint 18a is then dried and hardened to become the exterior material 18.

At this time, the length of the nozzles 22a and 24a is
As described above, since the diameter corresponds to the diameter of the element 14, the paint 18a is not applied to the lead wire 16 above the upper end of the element 14. Therefore, as shown in FIG. The tip of the sag or parting J of the exterior material 18 is located at the tangent to the element 14, and virtually no sagging or parting is formed.

In the embodiment shown in FIG. 1, when applying the paint 18a, the paint is sprayed while transporting each element 14, but the elements! The coating device 20 is fixed at the position of 4.
(nozzle) may be moved.

51st! I is a front view showing another embodiment of the present invention. In this embodiment, the nozzles 22a and 24m of the coating device W120 are arranged in the transport direction of the element 14, that is, the direction indicated by the arrow B of No. 51J, and the coating device zO is arranged vertically within the range indicated by the arrow in FIG. This differs from the embodiment shown in FIG. 1 in that it is movable.

In this example, the carrier tape IO is placed at the 51st J arrow B
Coat the element 14 by intermittently transferring it in the direction indicated by ! ! 20, the coating device 20 is displaced in the direction shown by the arrow in FIG.
By spouting the paint 18a from the paint 18a, the paint 18a is applied to the surface of the elm 14 to form the exterior material 1B.

In this embodiment as well, the number 22 of the coating device w120 is
Since a and 24a are not displaced to the portion of the lead wire 16 above the upper end of the element 14, no "sagging" or "parting" is formed.

Further, in the embodiment shown in FIG. 5, in order to absorb the positional deviation between the element 14 and the coating device 20, or to adapt the coating device i! The length of the row of ten nozzles 22a and 24a may be set to be sufficiently longer than the required length.
Furthermore, the arrangement of the nozzles 22a and 24a may be made longer so that the paint 18a can be applied to the surfaces of a plurality of elements 14 at the same time.

In this actual example, when applying the paint 18a, the paint was sprayed while moving the applicator 20 (nozzle). The injection may be performed while displacing each element 14 with the element 20 fixed.

FIG. 6 is a front view showing a modified example of the ejection part.

This spouting part 22 has holes for a large number of nozzles 22a.

They are distributed and arranged in a substantially circular shape corresponding to one main surface of the element 14. According to this embodiment, element 1
When applying the paint 181A to the paint 181A, the element 14 and the coating device 20 (nozzle) can be applied with the element 14 and the coating device 20 (nozzle) fixed.
Since there is no need to move f20 (nozzle), the application time can be shortened.

[Brief explanation of the drawing]

The first WJ is a front view showing an embodiment of the present invention. 2nd rI! J is a sectional view of a main part taken along line 1 in FIG. FIG. 3 is a sectional view showing an example of a nozzle. FIG. 4 is a front view showing an electronic component formed according to the present invention. FIG. 5 is a front view showing another embodiment of the invention. FIG. 6 is a front view showing a modified example of the ejection part. FIG. 7 is an illustrative view for explaining a conventional method of forming an exterior material by dipping. FIG. 8 is a front view showing an electronic component formed by a conventional method. FIG. 9 is a partial sectional view showing a state in which the electronic component shown in FIG. 8 is soldered to a printed circuit board. In the figure, 14 is an element and 16 is a lead. line, 18 is an exterior material, 18a is a paint, 20 is a coating device, 2
2 is a first ejection part, 22a and 24a are nozzles, 24 is a second ejection part, and 26 is a piezoelectric vibrator. Patent applicant Murata Manufacturing Co., Ltd. Representative Patent attorney Oka 1) Kei Zen (and 1 other person)

Claims (1)

[Scope of Claims] The method includes: preparing an element to which a lead wire is attached; aligning the element with a nozzle that ejects paint by vibration of a vibrator; and ejecting the paint from the nozzle. A method for forming exterior materials for electronic components.