JPS62162310A - Manufacture of insulating film of leadless electronic parts - 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 Field of Industrial Application The present invention relates to a method of forming an insulating film of a specified thickness to cover the main body of a leadless electronic component such as a chip resistor. Technology Conventionally, leadless electronic components such as chip resistors have been coated with an insulating film of a specified thickness on the main body of the element to prevent characteristics from changing due to changes in the external atmosphere and to protect the element. Covering 0 Hereinafter, a method for forming an insulating film on a leadless electronic component of this type will be explained using a cylindrical leadless electronic component as an example.

FIG. 4 shows an insulating coating formed on a cylindrical leadless electronic component 41 which is connected to a lead wire 41b for conveyance which can be removed later so as to protrude in different directions from both end surfaces of an element main body portion 41. It is a diagram showing the process,
The cylindrical leadless electronic component 41 has two parts arranged in parallel.
The book attachment lead wire 41b is held by the book attachment chain 42, and the book is transported to the position of the coating roller 43 where the insulating film is formed. The applicator roller 43 has a cross-sectional shape that allows it to pump up an appropriate amount of liquid paint from a paint tank (not shown) located at the bottom of the applicator roller 43. amount of paint is pumped up from the paint tank, and this application roller 43
At the upper position, the cylindrical leadless electronic component 41 is coated with paint. When applying this paint, when the element body portion 411L of the cylindrical leadless electronic component 41 comes into contact with the paint at the upper position of the application roller 43,
By forcibly rotating the cylindrical leadless electronic component 41, the element main body portion 4
A certain thickness of paint is applied to 11L.

The cylindrical leadless electronic component 41 coated with a certain amount of paint in this manner is sent to the next drying and curing step, and the paint is thermally hardened to form an insulating film.

Problems to be Solved by the Invention In such conventional methods, liquid paint has a large viscosity change over time and due to ambient temperature, and due to the change in viscosity, the cylindrical leadless electronic component 41
The amount applied to the element body portion 41 varies, making it difficult to form an insulating film with a constant thickness.

Furthermore, variations in the number of rotations of the application roller 43 and the number of forced rotations of the cylindrical leadless electronic component 41 by the drive belt 44 make it difficult to always form an insulating film with a constant thickness. There is a problem in that devices such as the drive belt 44 must be maintained and the viscosity of the paint must be carefully controlled.

Also, during coating, there is a lead for transporting the cylindrical leadless electronic component 41! 41b is brought into contact with the drive belt 44, thereby rotating the cylindrical leadless electronic component 41 and coating the entire circumference of the element main body portion 412L with a uniform film, but the conveying lead wire 41b may be bent. If it is eccentric, the element main body portion 41& will rotate unstablely, making it impossible to form a uniform coating film.

The present invention is intended to solve these conventional problems, and aims to make it possible to always form an insulating film that is uniform and has a predetermined thickness.

Means for Solving the Problem In order to solve this problem, the present invention applies pressure contact to the element body of a cylindrical leadless electronic component to adhere the paint to the element body, and then applies the paint to the element body. It is cured to form an insulating film.

With this configuration, unlike liquid paint, sheet paint has little viscosity change over time, and because it is pre-processed to a predetermined thickness, the amount of paint supplied to each cylindrical leadless electronic component can be reduced. As a result, a uniform insulating film having a predetermined thickness can be stably formed.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a diagram showing a schematic configuration of an apparatus in an insulating film forming process according to an example of the present invention, and FIG. 2 is a diagram showing the process. FIG. 3 is a diagram showing a process in which an insulating film is formed in FIG. Moreover, FIG. 3 is a diagram showing an example of a sheet-like paint, and the sheet-like paint 1 is used to prevent the sheet-like paint 1 from sticking to each other when the long sheet-like paint 1 is wound up in a loop shape and used. It is provided on the flexible paint conveying material 2.

As this sheet-like paint 1, in the following examples,
Although an epoxy-based thermosetting paint was used, it is not limited to this.
It is not necessary to use a paint of other type, such as a photocurable paint. Further, the sheet-like paint 1 is rubber-like and hardened at room temperature, but softens when the temperature rises slightly.

In FIG. 1, a cylindrical leadless electronic component 3 is connected to a pair of cylindrical leadless electronic components 3 that are arranged parallel to each other and move in the same direction at a constant speed v1 via lead wires for transportation that can be removed later. The chains 4 with attachments transport them in a state in which they are arranged in parallel rows on the same pitch.

The cylindrical leadless electronic component 3 transported from the previous process by the chain 4 with an attachment is first preheated to a predetermined temperature in the preheater 5 section, which is arranged so as not to come into contact with the cylindrical leadless electronic component 3. The adhesive roller 6.6' is then conveyed to the other pair of adhesive rollers 6.6'.The outer periphery of the adhesive roller 6.6' is lined with rubber of appropriate hardness.

The sheet-like paint 1.1' shown in FIG.
The sheet-like paint 1.1' that is wound on the supply reel 7.7' and supplied is placed on the adhesive roller 6 with the sheet-like paint surface side facing the cylindrical leadless electronic component 3 side. The sheet-like paint 1.1' is pressed into contact with the cylindrical leadless electronic component 3 by sandwiching it from above and below at this adhesive roller 6.6' section.
In this state, the chain is fed by the feed rollers 8, 8' at the same speed v1 as the attachment chain 4 while regulating its position.

9.9' is a winding roller that completely winds up only the paint conveying material 2.2' of the sheet-like paint 1, and the feed rollers 8, 8'
When the sheet-like paint 1 that is sent in pressure contact with the cylindrical leadless electronic component 3 passes the feed roller 8.8', only the paint conveying material 2.2' is peeled off and the sheet is transferred to the take-up roller 9. , 9'.

That is, at the adhesive roller 6.6' portion, the electronic component 3, which has been preheated to a predetermined temperature, is conveyed while being sandwiched from above and below by the sheet-like paint 1.1', while the peripheral surface speed of the outer peripheral surface is vl. The cylindrical leadless electronic component 3 is bonded to the cylindrical leadless electronic component 3 by the compression and preheating action of a pair of adhesive rollers 6゜6' that rotate at a high rotational speed and whose gap between them is set to be smaller than the outer diameter of the cylindrical leadless electronic component 3. A sheet-like paint 1 is pasted on the element main body 3 as shown in Figure 2.

The cylindrical leadless electronic components 3 to which the sheet-like paint 1 has been applied are sequentially conveyed to the pressure rollers 10° and 10'. The pressure rollers 10 and 10' are each lined with rubber having an appropriate hardness on their outer peripheries.

The outer circumferential surfaces of the pressure rollers 10 and 10' are in pressure contact with the cylindrical leadless electronic component 3 to which the sheet-like paint 1 is adhered, and the number of rotations thereof is such that the outer circumferential speed is This is the rotational speed at which the rotation speed becomes vl.

When the cylindrical leadless electronic component 3 to which the sheet-like paint 1 is pasted 7'' passes through the pressure rollers 10, 10', the upper and lower sheet-like paints 1, 1
' is bonded between the cylindrical leadless electronic components 3, and the cylindrical leadless electronic components 3'ff become continuously wrapped. In this state, the sheet-like paint 1.1' is not wrapped around the entire periphery of the element body of the cylindrical leadless electronic component 3, and is continuously transported to the next twisting rotation part. be done.

The twisting rotation unit is composed of rotating rollers 11 and 11' set at a rotation speed that pinches the lead wire of the cylindrical leadless electronic component 3 from the upper and lower blade directions and applies twisting rotational force in the advancing direction. . The outer peripheries of the rotating rollers 11 and 11' are also lined with rubber of appropriate hardness.

In this twist rotation part, the cylindrical leadless electronic component 3 is twisted and rotated so as to be pulled by a predetermined angle α in the traveling direction of the sheet-like paint 1.1"i, resulting in a state as shown in FIG. Paints 1 and 1' are continuously and closely wrapped around the entire periphery of the element body of each cylindrical leadless electronic component 3.

After that, by cutting unnecessary parts of the electronic component series wrapped with sheet-like paint in close contact with the element body, it is separated into individual cylindrical leadless electronic components 3 as shown in the second diagram. Then, by passing through a heating furnace heated to a predetermined temperature, the paint adhering to the cylindrical leadless electronic component 3 is cured, and an insulating film is formed. Finally, by applying all external force to the conveyance lead wires attached to both ends and removing them (FIG. 2E), a chip-shaped cylindrical leadless electronic component is obtained.

As is clear from the above examples, since the method involves pressurizing a sheet of paint onto electronic components to adhere the paint, and then curing the paint to form an insulating film, changes over time and changes in ambient temperature Therefore, the insulating coating 11i1 always has a uniform thickness without causing a large change in the film thickness.
- Can be formed.

Moreover, unlike liquid paints, sheet-like paints adhere to the paint conveying material in a hardened state, so they are easy to handle.

In addition, in the case of a liquid, if the coating roller is rotated at high speed to increase the coating speed, there will be a problem of paint scattering, but in the present application, such a problem does not occur at all, and the coating work can be done at high speed. I can do it.

Although the above embodiments have been explained using cylindrical leadless electronic components as an example,
It goes without saying that the present invention can be applied.

Effects of the Invention As described above, according to the insulating film forming method of the present invention, the insulating film is formed using a sheet-like paint;
It solves the conventional problem of unstable film thickness due to changes in viscosity over time or changes in ambient temperature, and also makes it easier to handle the paint and speeds up the coating process. 0, which has the excellent effect of being able to

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the main parts of the apparatus in the force method for forming an insulation film for cylindrical leadless electronic components according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the state of the main parts of the process in the same method. , FIG. 3 is a perspective view showing an example of a sheet-like paint used in the same method, and FIG. 4 is a schematic configuration diagram showing the main parts of equipment in a conventional method for forming an insulating film for electronic components. ... Sheet paint, 3 ... Electronic parts, 6゜6'-°° ... Adhesive roller, 1o, 10
1...Crimping roller. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure (Han (B)l
′ (Li (D
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Claims (2)

[Claims] (1) A leadless electronic component characterized in that a sheet-like paint is pressed against the element body of the leadless electronic component to adhere the paint to the element body, and then the paint is cured to form an insulating film. Insulating film forming method. (2) Press a long sheet of paint onto each of the element bodies of multiple electronic components arranged side by side to adhere the paint to each of the element bodies, and then attach multiple electronic components to each individual unit. A method for forming an insulating film on a leadless electronic component, which comprises, after separation, curing the paint adhering to each electronic component to form an insulating film.