JP2001244040A - Connecting method of resin coated wire such as magnetic wire to land or pad provided on glass epoxy board and electric circuit, etc. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrically mechanically connecting method of the resin coated wire such as the magnet wire to the land or pad on an electrical component, an electronic part and the glass epoxy board, etc., without removing the coating. SOLUTION: Using parallel gap welding process in which the electrode is in pairs, there is sandwiched a high resistive metal foil at the contact surfaces between the magnet wire and a pair of electrode end faces, thereby obtaining intermolecular bonding through thermo-compression bonding process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for electrically and mechanically applying land and pads to ordinary circuit boards and electric parts without removing coatings such as magnet wires having a wire diameter of about 0.1 mm or less. The present invention relates to a method for performing joining.

[0002]

2. Description of the Related Art Conventionally, solder is used for joining a magnet wire or the like to a land or the like, that is, after a wire is immersed in a solder bath having a temperature higher than the melting point of the coating material to remove the coating,
There is a method of joining that portion to a land or the like, or connecting directly with solder after removing the coating by directly using the heat generated by a soldering iron.

Further, in accordance with the resistance welding method, a high current of about tens to hundreds of amperes is applied to a metal heater chip made of a high resistance material for about ten milliseconds to several seconds to generate heat and pressure. There is a construction method in which the core wire is hot-pressed to the land at the same time as removing the coating.

[0004]

In the soldering method, there is a limit in shortening the process time, and in the hot pressing method using a heater chip, the life of the chip is very short with respect to the price of the chip itself, and the cost occupying the entire process is reduced. There was a problem.

[0005]

In order to solve the above problems, the present invention uses a welding head and an electrode tip used in a resistance welding method, and uses a metal foil having a high resistance value as a heating element. Thus, at the same time as removing the coating of the magnet wire or the like, the core wire is heat-pressed to the land portion to obtain an intermolecular bond between the metal base materials at the wire core wire and the land upper surface portion.

[0006]

The present invention uses a pair of resistance welding electrodes and a metal foil, which are arranged in parallel with each other, usually called a parallel gap, and insulated between them, and a welding head. The material of the electrode and the metal foil is a high-resistance material such as pure molybdenum or tungsten. The end face where the pair of electrodes is in contact with the metal foil is processed into a square or the like having one side of about 2.5 times the wire diameter of the magnet wire to be joined. It is important to focus. In addition, the end surfaces of the pair of electrodes are arranged such that, for example, when the electrodes are installed vertically, the two lower ends push the joint at the same level in the horizontal direction. This is important for obtaining stable heat generation by making the contact resistance uniform with respect to the metal foil.

A metal foil having a thickness of about 10 to 25 μm is sandwiched between the above-mentioned electrode end face and a magnet wire or the like having a wire diameter of about 0.1 mm or less. Then, the metal foil and the magnet wire are pressed against the surface of the joint by applying a constant pressure of about 40 to 800 grams.

When the pressurization reaches a predetermined value, a limiter switch of the welding head is operated, and a welding power source having a feedback function applies a voltage of about 3 volts to a pair of electrodes in a short time of 10 to 50 milliseconds. Electric energy of less than several tens to one hundred and several tens of amperes is supplied. This energization has no danger to the human body due to electric shock because the output voltage is low according to resistance welding.

During energization, a feedback function of the welding power source operates, and predetermined energy is continuously applied to the electrodes.
In the metal foil, a local area in contact with the end face of the electrode is
Very high temperature resistance heat generation exceeding 0 degrees is generated. Utilizing the heat generated by the metal foil and the pressure of the electrode, the coating of the magnet wire is removed, and at the same time, the core wire is thermally pressed onto the land. At this time, the core wire is deformed by the applied pressure.

When the energization is completed, the heat generated locally is rapidly radiated. The core wire of the magnet wire achieves a molecular indirect signal on the land.

Thereafter, the pressure applied to the electrode from the welding head is released, and the electrode returns to the origin position. At that time, the contact part between the magnet wire and the metal foil, and the contact part between the metal foil and the electrode end face are easily separated from each other,
It is possible to respond to the next successive step.

The metal foil once passed through the process is affected by heat, and there is a concern that a problem may occur when performing the process continuously.
After a predetermined number of steps are completed, the metal foil is wound up by a reel or the like, and the same process is continuously performed at a new portion of the continuous metal foil.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment will be described. FIG. 1 is a schematic diagram showing a state immediately before a current is supplied from a welding power source 1 to an electrode 3a. The electrode 3a is electrically insulated between two parallel electrodes, and is provided with a secondary holder 2b, 2c of 14 square mm or more from a welding power source through a dedicated holder.
Connected by The electrode end face in contact with the metal foil is processed into a square or the like having one side of about 2.5 times the wire diameter of the magnet wire, and the shape and material of each pair are the same. Particularly, the material is preferably pure molybdenum or tungsten. The end faces need to be smoothed in a uniform state. Further, it is necessary to devise a dedicated holder provided in the electrode head 2a so that the electrode 3a can be easily replaced and maintained. The electrode holder is made of a material having good heat conduction and electrical conductivity.

The welding head 2a presses the metal foil 4a and the magnet wire 5 through the end surface of the electrode 3a against the land 6 which is a pattern on the substrate 7 until the operator reaches the set pressure.

FIG. 2 shows the arrangement of the metal foil delivery reel 8 and the take-up reel 9. In this figure, the power supply 1 is omitted, and only one electrode 3b can be seen due to the angle. Before the pressurizing operation is started, the welding head 2 a
b is at the origin position, and therefore the metal foil 4b is not in contact with the electrode 3b or the magnet wire 5. When the electrode 3 is lowered by the operation of the welding head 2, the metal foil 4 b is disposed so as to be securely sandwiched between the end face of the electrode 3 b and the magnet wire 5 and press the surface of the land 6 on which the wire is arranged on the substrate 7. You.

FIG. 3 schematically shows a state in which the energization is completed immediately after FIG. When the limit switch mounted on the welding head 2a reaches an arbitrary pressurization value set to about several hundred grams, a signal is immediately sent to the welding power source 1 and immediately after that, the electrode 3a is energized. From electrode 3a to metal foil 4
The electric energy supplied to a generates heat rapidly due to the specific resistance of the metal foil and the contact resistance with the electrode,
During energization, the coating of the magnet wire is instantaneously volatilized, and the electrode and the metal foil press the core wire 10 of the stripped magnet wire directly against the land 6 so that the portion between the land and the stripped core wire is pressed. In this case, intermolecular bonding 11 occurs due to thermal pressure welding.

During energization, the feedback function of the welding power source 1 ensures that stable energy is supplied at all times during energization time.

After the end of the energization, the core wire of the magnet wire is deformed into a crushed state and pressed against the land due to heat and pressure. In addition, the coating portion of the magnet wire that has been affected by heat is instantaneously volatilized and does not remain on the land, but the portion that has escaped volatilization and another coating 12 that is not affected by heat retains the coating of the wire. .

Thereafter, as shown in FIG. 4, after the power supply is completed, the head 2a is operated to return the electrode 3b to the origin position. At this time, the electrode 3b, the metal foil 4b, and the core wire 1 of the magnet wire
0 does not affect the next step because it is easily separated. If necessary, the reels 8 and 9 are operated to move the metal foil to process the subsequent steps.

FIG. 5 shows an example of a parallel gap welding electrode. The electrodes are symmetrical when viewed from the front, and the right and left electrode materials are integrated with the central insulating layer 13, and the thickness of the insulating layer is about 0.05 mm. Further, when looking at the end face of the electrode from directly below the figure, the shape of the contact surface is symmetrical with respect to the left and right with the insulating layer 13 interposed therebetween.
The size of the side of the end face is about 0.13 to 0.5 mm per side. The entire body is cylindrical and has a diameter of about 3 mm, and the entire length is about 30 mm. This product is made of pure molybdenum.

[0021]

The present invention is embodied in the form described above and has the following effects.

In order to use a parallel gap welding electrode,
A pair of electrodes can be brought into contact with the flat joint portion from one direction.

The use of metal foil allows the foil to come into contact with the coating according to the pressure even when the coating shape is complicated, such as when there are a plurality of core wires. Has a remarkable effect on completely removing the core and thermally pressing the core wire.

[0024] By winding the used portion affected by the heat of the metal foil on a reel, the process can be continuously performed on a new portion in a stable state.

Since pressure is applied by the welding head and the electrode, it is possible to expect thermal pressure welding with reliable intermolecular bonding by means of a pressure control according to welding and an energizing method using a feedback function.

[Brief description of the drawings]

FIG. 1 is an outline of the arrangement of main articles immediately before applying electric energy for bonding.

FIG. 2 is a view in which the arrangement of FIG. 1 immediately before the start of the head operation is viewed from the end face direction of the magnet wire, and the arrangement of a take-up reel or the like of a metal foil is added.

FIG. 3 is an outline of a main article immediately after completion of energization for joining.

FIG. 4 is a view in which the arrangement of a take-up reel or the like of a metal foil is added to the situation as viewed from the end face of the core wire of the magnet wire after the completion of one process.

FIG. 5 is an example of a parallel gap welding electrode and an outline of an end surface contact portion.

[Explanation of symbols]

1 Outline of welding power source 2a Outline of welding head equipped with electrodes and dedicated electrode holder 2b Outline of secondary conductor wire connected to one side of a pair of parallel gap welding electrodes 2c Secondary connected to the other side of a pair of parallel gap welding electrodes Outline of conductor wire 3a Outline viewed from front of a pair of parallel gap welding electrodes 3b Outline viewed from side of a pair of parallel gap welding electrodes 4a Outline of metal foil 4b Outline showing relationship between metal foil and reel 5 Magnet wire to be joined 6 Outline of land or pad arranged on board to be bonded 7 Outline of glass epoxy board 8 Outline of reel for stocking metal foil 9 Outline of reel for winding used metal foil 10 Heat Outline of pressed core wire such as magnet wire 11 Molecule on the contact surface between core wire such as magnet wire and land Insulating layer summary 13 integral parallel gap welding electrodes from the end surface of the magnet wire is not subjected to site 12 thermal effect bonding occurs

Claims (1)

[Claims] [Claim 1] Connection method, construction method