JPH0638330A - Stripping method for enameled wire - Google Patents

Abstract

PURPOSE:To provide highly reliable laser stripping method for various enameled wires. CONSTITUTION:The laser stripping method for enameled wire comprises a prestep for irradiating an enameled wire with laser beam wherein the surface to be irradiated with laser beam is previously coated with a medicine functioning to remove oxides from the surface of metal conductor of the enameled wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing an enamel film from an insulated wire.

[0002]

2. Description of the Related Art With the recent miniaturization and higher functionality of electronic devices and the like, the environment in which the components and coils used therein are used has become extremely severe. For this reason, it is becoming important to make the insulated wires used for these parts and coils highly heat resistant and thin, but on the other hand, enamel film end stripping technology, which greatly affects quality and workability, is sufficient. However, there is a problem that it is not possible to achieve high heat resistance and thin lines.

That is, in mechanical peeling, a problem of fatal conductor scratches is generated in fine wires, and in chemical peeling, a stronger peeling agent is used to deteriorate the peeling peripheral portion of the insulating film or to remove the attached peeling agent for a long time. However, the problem of softening / disconnection of the conductor itself could not be satisfied by the burning removal method using fire.

Therefore, in recent years, as a method for improving these problems, research has been actively conducted on an enameled wire which can be directly peel-soldered and capable of heat-resisting soldering, but it is sufficient to maintain solderability. It has not yet been achieved to impart heat resistance. Further, research on a peeling method using a laser has been further activated, and a thin wire of heat resistant enamel insulation capable of easily peeling a film has been developed, but it was necessary to limit to a material having a special constitution.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to easily and quickly use a laser without specifying the material of the enamel film of the insulated wire that can be treated. In addition, the present invention provides a peeling method capable of highly reliable peeling treatment of an enamel film.

[0006]

[Means for Solving the Problems] In a method of peeling an enamel film of an insulated wire using a laser, as a pre-process of irradiating the insulated wire with a laser, a laser-irradiated surface of the insulated wire to be irradiated is a metal conductor surface of the insulated wire. Incorporating a step of pre-applying a drug having a function of removing the oxide, and then irradiating the drug application site with a laser.

In the present invention, examples of the agent having a function of removing oxides on the surface of the metal conductor include pine resin, phosphoric acid,
Hydrochloric acid, hydrofluoric acid, orthophosphoric acid, zinc chloride, ammonium chloride, stannous chloride, lactic acid, stearic acid, oleic acid, glutamic acid, phthalic acid, aniline hydrochloride, glutamine hydrochloride, hydrazine hydrochloride, urea, ethylenediamine,
Rosin acid, modified phenol, etc. can be used, and these agents are mixed with one or more kinds, or diluted with water or a solvent in order to obtain uniform release characteristics, or for viscosity adjustment, thickening. It is preferable to prepare and use by adding agents and the like. The higher the drug concentration, the greater the effect, but it is desirable to adjust the concentration to about 1000 centipoise (30 ° C.) in order to make the adhesion amount uniform.

Examples of the enamel insulated wire to which the method of the present invention can be applied include polyimide resin, polyamideimide resin, polyesteramideimide resin, polyhydanton resin, polyesterimide resin, polyparabanic acid resin, polyester resin, polyvinyl formal resin and polyurethane resin. Most of the enamel insulated wires having a thermosetting resin or a composite insulating layer formed by combining two or more of these resins are possible.

Further, as the laser used in the present invention, an excimer laser or a carbon dioxide laser, and a laser having a high output is particularly preferable.

[0010]

In the method of the present invention, a step of applying a chemical agent having a function of removing oxides on the surface of the metal conductor in advance to the laser-irradiated surface of the insulated wire to be irradiated is incorporated as a pre-step of the step of laser irradiation. Decomposition of insulating coating material by laser irradiation and formation of trace amount residue and conductor oxide layer (copper oxide) by adhesion permeation to the exfoliation part of the minute volatile agent which has the function of removing the oxide on the metal surface. Since the copper oxide is reduced and the adhesion of the decomposed trace amount residue is also reduced at the same time, the penetration and diffusion of the solder to the conductor surface are significantly improved.

[0011]

Example 1 (Preparation of polyester resin coating) 1.0 mol of dimethyl terephthalate and 0.6 mol of ethylene glycol,
0.5 mol of glycerin was put into a flask, the mixture was heated and reacted with stirring, the reaction was allowed to proceed while allowing methanol to flow out, and the reaction temperature was raised to about 220 ° C. When the viscosity of the reaction product rapidly increased, cresol was added to this reaction system to dissolve the reaction product and cool the temperature of the solution to 80 ° C. Next, 12 g of tetrabutyl titanate was added to this solution and stirred for about 3 hours, and then cresol and solvent naphtha were added to this reaction product for dilution to prepare a polyester resin coating material having a nonvolatile content of 30%. (Production of Insulated Electric Wire) The above-mentioned polyester resin coating material was applied onto a copper wire having a diameter of 0.1 mm and baked to obtain an insulated electric wire having a polyester resin film with a film thickness of 10 μm.

Using the polyester enamel wire thus produced, various chemicals were evenly applied to the 10 mm portion of the end to make a sample wire. Further, the end portion of the sample wire thus produced is irradiated with a laser under the following CO ₂ gas laser irradiation conditions to peel the polyester enamel film from the insulated wire, the irradiation time required for the peeling, and the peeling treatment. Then, the solderability of the exposed conductor was examined. The results obtained are shown in Table 1.

Carbon dioxide laser irradiation condition (TEA type carbon dioxide laser irradiation device) Irradiation area: 10 mm × 2 mm Irradiation output: 4 joules Irradiation direction: 2 directions Irradiation frequency: 5 Hz (5 times / sec) Solderability Laser irradiation By immersing the exposed conductor in a solder bath (Pb / Sn = 50/50) at 380 ° C. for 2 seconds, the time until the solder was satisfactorily soldered to the conductor and its state were examined.

[0014]

[Table 1]

Example 2 An insulated wire having the same polyesterimide resin film as in Example 1 was produced using a polyesterimide resin coating (trade name: Isomid RL: manufactured by Nippon Schenectady). Using the polyesterimide enameled wire thus produced, various chemicals were evenly applied to the entire 10 mm portion of the end to prepare a sample wire. The same test as in Example 1 was conducted on the terminal portion of the sample wire thus produced. The obtained results are shown in Table 2.

[0016]

[Table 2]

Example 3 A polyester imide resin coating (trade name: Isomid RL, manufactured by Nippon Schenectady) was applied on a copper wire having a diameter of 0.1 mm, and a baking process was repeated to form a polyester imide resin film having a thickness of 5 μm. After being provided, a polyamide-imide resin coating (trade name HI-405, manufactured by Hitachi Chemical Co., Ltd.) is applied on this film, and the baking step is repeated,
An insulated wire was manufactured. The same test as in Example 1 was performed on the terminal portion of the double-coated insulating sample wire thus produced.
The results obtained are shown in Table 3.

[0018]

[Table 3]

Example 4 A polyamide-imide resin coating (trade name: HI-405, manufactured by Hitachi Chemical Co., Ltd.) was applied on a copper wire having a diameter of 0.1 mm, and the baking process was repeated. An imide resin film was formed to produce an insulated wire. With respect to the polyamide-imide enameled wire thus produced, various chemicals were evenly applied to the entire 10 mm of the end to produce a sample wire. The same test as in Example 1 was performed on the terminal portion of the sample wire thus produced. The results obtained are shown in Table 4.

[0020]

[Table 4]

Example 5 A polyimide resin paint (Pire ML, trade name) was used with a diameter of 0.1.
A copper wire having a thickness of 10 mm and a baking process were repeated to form a polyimide resin film having a thickness of 10 μm to produce an insulated wire. With respect to the polyimide enamel wire produced in this way, various chemicals were evenly applied to the end 10 mm to make a sample wire. The same test as in Example 1 was performed on the terminal portion of the sample wire thus produced. The results obtained are shown in Table 5.

[0022]

[Table 5]

As is clear from Tables 1 to 5, according to the method of the present invention, the enamel coating of various enamel insulated wires can be easily and reliably stripped in a short time.

[0024]

As described above, according to the method for peeling off an enamel film of the present invention, various kinds of enamel films for insulated wires are not limited to a particular one by using an inexpensive laser such as a carbon dioxide gas laser. Enamel coating of easily,
Moreover, it can be peeled off with high reliability, and its practical value is extremely large.

Claims (3)

[Claims] 1. A method for removing an enamel coating of an insulated wire using a laser, wherein as a pre-process of irradiating the insulated wire with a laser, an oxide on the metal conductor surface of the insulated wire is applied to a laser-irradiated surface of the insulated wire to be irradiated. A method for removing an enamel film of an insulated wire, which comprises a step of applying a chemical agent having a function of removing in advance. 2. The agent applied to the laser-irradiated surface of the insulated insulated wire is pine resin, phosphoric acid, hydrochloric acid, hydrofluoric acid, orthophosphoric acid, zinc chloride, ammonium chloride, stannous chloride, lactic acid,
Stearic acid, oleic acid, glutamic acid, phthalic acid,
At least one kind selected from the group consisting of aniline hydrochloride, glutamine hydrochloride, hydrazine hydrochloride, urea, ethylenediamine, rosin acid, and modified phenol, or a solution thereof dissolved in water or a solvent. The method for peeling off an enamel film of an insulated wire according to 1. 3. The method for peeling an enamel film of an insulated wire according to claim 1, wherein either one of an excimer laser and a pulsed carbon dioxide gas laser is used as the irradiated laser.