JPH09260010A - Apparatus and method for joining sheet materials - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably join it without thermally deforming a sheet-like material by generating heat in a pair of metallic plates by a line of magnetic force, and pressurizing and sandwiching the sheet like material arranged in layers by these heated metallic plates. SOLUTION: A sheet material S by superposing a rigid printed wiring board 51 and a flexible printed wiring board 52 on each other through a joining member, is set on a receiving stand 1. A magnetic force line generating head 5 is lowered by a motor 8, and a high frequency electric current is carried to an induction coil 19 by driving an oscillating circuit 7, and a high frequency magnetic flux is generated. When the magnetic force line generating head 5 descends, the high frequency magnetic flux acts on a metallic plate (B)3, and it is heated, and when it is pushed down by coming into contact with a holding plate 4, a metallic plate (A)2 is heated. The joining sheet material S on the receiving stand 1 is sandwiched by these heated metallic plates (A)2 and (B)3, and is held for a prescrined time under prescribed pressure. Therefore, since it can be joined by adding suitable heat to the sheet material S, the occurrence of thermal deformation can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for joining sheet-like materials used for joining sheet-like printed wiring boards.

[0002]

2. Description of the Related Art In the field of wiring technology using printed wiring boards, a part or all of a plurality of flexible printed wiring boards are overlapped with each other, and some of them are pressed and heated to be joined, or a flexible printed circuit board is used. A method is used in which a part or all of a rigid printed wiring board is overlapped and a part of the rigid printed wiring board is pressed and heated to be bonded.

FIG. 5 shows an example of a conventional joining method. In FIG. 5, an example is shown in which the rigid printed wiring board 51 and the flexible printed wiring board 52 are joined. In this method, the joint portion of the rigid printed wiring board 51 and the flexible printed wiring board 5 are joined together.
The pedestal 53 on which the two joints are placed on top of each other
And a heating head 54 arranged above the receiving base 53
And The heating head 54 is moved in the vertical direction by a driving unit (not shown), and at the position where the heating head 54 is moved downward, the joint portion of the rigid printed wiring board 51 mounted on the receiving table 53 and the flexible printed wiring board 52. The joint portion and the pedestal 53 can be strongly pressed. Further, a resistor (not shown) is arranged in the heating head 54, and the controller 5 is attached to this resistor.
It has a structure in which an electric current is supplied from 5 to heat the press surface.

When joining the joint portion of the rigid printed wiring board 51 and the joint portion of the flexible printed wiring board 52, first, the joint portion of the rigid printed wiring board 51 and the joint portion of the flexible printed wiring board 52 are overlapped. And set it on the cradle 53. In the following description, the rigid printed wiring board 51 and the flexible printed wiring board 52, which are in a state where the joining portions are overlapped with each other, are collectively referred to as the joining sheet material S.
Say Then, the heated heating head 54 is lowered by the driving means, and the heating head 54 strongly presses the portion to which the joining sheet material S is joined against the pedestal 53. Then, the bonding agent (reflow solder in this example) interposed between the joint portion of the rigid printed wiring board 51 and the joint portion of the flexible printed wiring board 52 is melted. Next, when the heating head 54 is raised and the pressing is released, the joint portion is cooled and the reflow solder is solidified, and the joint portion is joined by the reflow solder.

[0005]

As described above, in the conventional joining method, the heating head 54 is joined by thermocompression bonding from one side, and the flexible printed wiring board 52 is supplied to the rigid printed wiring board 51 for heat supply. Done through. Therefore, if too high heat is applied by the heating head 54, the flexible printed wiring board 52 is likely to be thermally deformed and warped or the like. As a result, stable bonding may not be possible in some cases, resulting in poor yield. On the other hand, there is a problem that when the joining is performed with a too low heat, the influence of the tact time occurs and the productivity is reduced. further,
The heating head 54 has a structure in which a resistor is arranged inside and a current is passed from the controller 55 to the resistor to heat the press surface. However, the structure is generally complicated and large in size,
There is also a problem that the weight of the entire apparatus is increased and it is difficult to carry it to the installation position.

The present invention has been made in view of the above problems, and an object of the present invention is to join sheet-like materials capable of improving the yield and improving the productivity and reducing the size and weight of the apparatus. An apparatus and method are provided. Further, other objects will be clarified sequentially in the contents described below.

[0007]

In order to achieve the above-mentioned object, the present invention is characterized in that the following technical means is taken as a joining device for sheet-like materials. That is, a cradle, a magnetic force line generating head arranged above the cradle, a driving means for reciprocating the magnetic force line generating head, an oscillating circuit means for supplying a predetermined high frequency current to the magnetic force line generating head, Between the metal plate A arranged on the pedestal and the metal plate A, which is arranged so as to face the metal plate A and is pressed against the metal plate A side by the movement of the magnetic force line generation head. And a metal plate B for pressing and sandwiching the sheet-like materials a and b, which are arranged so as to overlap each other, together with the metal plate A, and the metal plate is formed by an eddy current generated by the magnetic force lines generated by the magnetic force line generation head. Heat is generated in A and B, and the sheet materials a and b are joined by the heat of the heated metal plates A and B.

In order to achieve the above object, the present invention is characterized in that the following technical means is taken as a method for joining sheet-like materials. That is, metal plates A and B that generate heat by eddy currents generated by the magnetic force lines generated by the magnetic force line generation head are arranged above and below a plurality of sheet-shaped materials a and b that are placed on the pedestal so as to be superimposed on each other. , The sheet-shaped materials a and b are pressed and sandwiched by the arranged metal plates A and B, and the sheet-shaped materials a and b are joined by the heat of the heated metal plates A and B. It was done like this.

Therefore, according to the sheet-shaped material joining apparatus and method of the present invention, both the metal plates A and B sandwiching the sheet-shaped materials a and b are eddy current generated by the high-frequency magnetic force lines generated from the magnetic force line generation head. Each is heated and the sheet-shaped material a,
Heat can be applied to each of the sheet-shaped materials a and b from both sides of b to join them.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual structural diagram of a joining device shown as an example of one embodiment of the present invention. Further, this joining device exemplifies a case where a rigid printed wiring board and a flexible printed wiring board are joined. Therefore, the rigid printed wiring board and the flexible printed wiring board will be described below with the same reference numerals as those of the rigid printed wiring board 51 and the flexible printed wiring board 52 shown in FIG.

In FIG. 1, this joining device is shown in FIG.
And a metal plate (A) 2, a metal plate (B) 3, a holder 4, a magnetic force line generation head 5, a controller 6, an oscillation circuit 7, a motor 8, a motor driver 9, a pressure sensor 10, and a temperature sensor 1.
It is composed of 1 etc.

More specifically, the cradle 1 is fixedly disposed on the main body of the apparatus (not shown), and the metal plate (A) 2 is fixedly mounted on the cradle 1.

The metal plate (A) 2 is formed as a ring-shaped plate as a whole by punching and molding a metal material, as shown as a single piece in FIG. In addition, a part 2D to be a heating part (hereinafter, this part is referred to as "heating part 2D")
Are integrally extended outside the main body portion 2C on the same plane. Further, a slot 12 is formed in the heating portion 2D from the inside of the main body portion 2C. In addition, the tip portion of the groove 12 spreads to both sides, and due to this spreading, the narrowed constricted portion 1 is formed at the joint portion between the main body portion 2C and the heating portion 2D.
It has a structure provided with 3. This constricted portion 13 is
As will be described later, when a high-frequency magnetic field line is applied to the metal plate (A) 2, the resistance value becomes higher than other portions, and heat is generated in the heating portion 2D (a portion shown by hatching in FIG. 3). Can be concentrated. The heating unit 2
As a means for concentrating heat generation on D, the thickness of the heating portion 2D is made smaller than the thickness of the main body portion 2C to increase the resistance value,
A method of concentrating heat generation may be adopted.

The metal plate (A) 2 is heated by the heating unit 2.
It is arranged on the pedestal 1 with D as the outside, but when arranged, the outer periphery is covered with the electric insulating cover 14,
Also, the structure is insulated from the bonding sheet material S. Also,
A temperature sensor 11 that detects the temperature of the metal plate (A) 2 and inputs the temperature to the controller 6 and the oscillation circuit 7 is attached to the metal plate (A) 2 arranged on the pedestal 1.

The holder 4 is made of a ferrite material having a high magnetic permeability and is formed into a substantially disc shape.
It is arranged above. The holder 4 is movable in the vertical direction by means not shown, and is normally urged to move upward, that is, in a direction away from the pedestal 1. Further, a metal plate (B) 3 is attached to the bottom surface of the holder 4.

The metal plate (B) 3 is formed as a ring-shaped plate as a whole by punching and molding a metal material similarly to the metal plate (A) 2 as shown in FIG. There is. Further, a part 3D serving as a heating part (hereinafter, this part is referred to as “heating part 3D”) is integrally extended outside the main body part 3C on the same plane. Further, a slot 15 is formed in the heating portion 3D from the inside of the main body portion 3C. In addition, the tip of the groove 15 expands to both sides, and due to this expansion, a narrow constricted part 16 is provided at the joint between the main body 3C and the heating part 3D. This constricted portion 16 is similar to the case of the metal plate (A) 2,
When a high-frequency magnetic field line is applied to the metal plate (B) 3, the resistance value becomes higher than other portions, and heat generation can be concentrated in the heating portion 3D (in the portion shown by hatching in FIG. 4). . As a means for concentrating heat generation in the heating section 3D, as in the case of the metal plate (A) 2, the heating section 3D is formed to have a smaller thickness than the main body section 3C to increase the resistance value. A method of concentrating heat generation may be adopted. The heating portion 3D of the metal plate (B) 3 is formed to have substantially the same size as the heating portion 2D of the metal plate (A) 2, but the main body portion 3C has a diameter smaller than that of the metal plate (A) 2. It is formed small. This enlarges the main body portion 2C of the metal plate (A) 2 to suppress heat generation on the pedestal 1 side except for the heating portion 2D.

When the metal plate (B) 3 is attached to the holder 4, it is attached to the holder 4 with the heating portion 3D facing outside and corresponding to the heating portion 2D of the metal plate (A) 2. Further, when arranged, the outer periphery is covered with the electric insulating cover 17 to be insulated from the holder 4 and the bonding sheet material S. As the material of the metal plates (A) and (B), an iron plate is used in this example, but copper or various stainless steels may be used. In this case, for example,
The metal plate (A) and the metal plate (B) can be made of different materials.

The magnetic field line generating head 5 is provided above the holder 4.
That is, it is arranged above the cradle 1. The magnetic force line generating head 5 has a structure in which an induction coil 19 is wound around a block 18 made of a magnetic material having a high magnetic permeability such as a ferrite material. Further, the induction coil 19 is an oscillation circuit 7 for generating a high frequency current of, for example, several tens KHz.
It is connected to the. In addition, a driving means 20 having a motor 8 is connected to the upper surface of the magnetic force line generation head 5, and the magnetic force generation head 5 is reciprocally moved in the vertical direction by using the motor 8 as a drive source. Then, the joining sheet S is pressed against the pedestal 1 side through the holding body 4 with a predetermined pressure. The pressing force is detected by the pressure sensor 10 mounted between the moving body 21 and the block 18 which are vertically reciprocated by the motor 8 of the driving means 20, and the output of the pressure sensor 10 is input to the controller 6. It Then, conversely, a signal for driving the motor 8 is output from the controller 6 via the motor driver 9, and the motor 8 is stopped when a predetermined pressing force is reached.

FIG. 2 is a flow chart showing an example of the operation processing procedure of this joining apparatus. Therefore, next, the operation of the joining apparatus shown in FIG. 1 will be described with reference to FIG. First, when the joining sheet material S is set, the magnetic force line generation head 5 is moved upward by the driving means 20 and is separated from the holding body 4. Further, as a result, the holding body 4 also moves upward together with the metal plate (B) 3, and a sufficient gap for setting the joining sheet material S between the metal plate (B) 3 and the metal plate (A) 2. Are formed. Note that FIG. 1 shows this state. The joining sheet material S is a dispenser or the like as a joining agent at a predetermined position of the wiring of the rigid printed wiring board 51 or the flexible printed wiring board 52 on which the electronic components forming the electronic circuit are placed and soldered. In this state, the cream solder is supplied and applied so as to be superposed in advance, and in this state, the cream solder is positioned and set by a positioning pin or the like (not shown) (step ST1).
Then, the portion to be joined is arranged on the heating portion 2D of the metal plate (A) 2.

Next, the start switch is pushed by the operator. Then, the motor 8 is driven to lower the magnetic force line generation head 5, and the oscillation circuit 7 is driven to supply the high frequency current to the induction coil 19. As a result, a high frequency magnetic flux is generated from the induction coil 19 (step ST2).

When the magnetic force line generating head 5 is moved down to a predetermined position and approaches the holder 4, the high frequency magnetic flux from the magnetic force line generating head 5 acts on the metal plate (B) 3 and the metal plate (B). ) 3 induces and generates an eddy current, and the metal plate (B) 3 generates heat (step ST3). This heat generation is concentrated in the heating section 3D for the reason described above.

Further, when the magnetic force line generating head 5 is lowered, the magnetic force line generating head 5 is brought into contact with the holding body 4,
The holder 4 is pushed downward together with the metal plate (B) 3 (step ST4). Further, during this process, the high-frequency magnetic flux from the magnetic force line generation head 5 also acts on the metal plate (A) 2. Then, an eddy current is induced and generated in the metal plate (A) 2, and the metal plate (A) 2 generates heat (step ST5).
This heat generation also concentrates on the heating section 2D for the reason described above.

When the magnetic field line generating head 5 is further lowered,
The joining sheet material S is sandwiched between the metal plate (A) 2 and the metal plate (B) 3, and this is held at a predetermined pressure for a predetermined time (step ST6). Further, this pressing force is detected by the pressure sensor 10, its output signal is supplied to the controller 6, the control signal is sent from the controller 6 to the motor driver 9 by also referring to the output signal from the temperature sensor 11, and the joining sheet is joined. A pressing force suitable for the material S is applied and pressed for a predetermined time. Then, the cream solder previously applied as a bonding agent to the bonding sheet material S is reflowed, so that the rigid printed wiring board 51 and the flexible printed wiring board 52 are soldered.

When the pressing for a predetermined time is completed, a control signal is supplied from the controller 6 to the motor driver 9 to rotate the motor 8 in the reverse direction. Then, the magnetic force line generation head 5 is moved to the upper position and stopped when reaching the predetermined position (step ST7). As the magnetic force line generation head 5 rises, first, the magnetic force line generation head 5 is separated from the metal plate (A) 2, so that the generation of the eddy current in the metal plate (A) 2 is reduced and the metal plate (A) 2 is reduced. Fever is eliminated.
Further, the magnetic force line generation head 5 moves the holder 4 to a predetermined position.
Then, only the magnetic force line generating head 5 is raised thereafter. Then, as the magnetic force line generation head 5 rises apart from the holder 4, the generation of eddy current in the metal plate (B) 3 decreases, and heat generation of the metal plate (B) 3 is also eliminated. As a method of controlling the heat generation and elimination of the metal plates (A) 2 and (B) 3, the oscillation by the oscillation circuit 7 is stopped by a switch operation or the like before the magnetic field line generation head 5 is raised to a predetermined position. Although it may be possible to do so, in the present embodiment, when the magnetic field line generating head 5 returns to a predetermined position, it is turned off by a switch and the driving of the oscillation circuit 7 is stopped (step ST8). After that, by repeating this series of operations, the joining sheet materials S that are successively supplied can be joined.

Therefore, according to the joining apparatus of this embodiment, the metal plate (A) sandwiching the joining sheet material S by the eddy current generated by the high frequency magnetic force lines generated by the magnetic force line generating head 5.
Both 2 and (B) 3 can be respectively heated, and heat can be applied from both sides of the bonding sheet material S to bond them. As a result, the following effects can be expected. Since it is possible to bond the rigid printed wiring board 51 and the flexible printed wiring board 52, which form the bonding sheet material S, with appropriate heats respectively, the flexible printed wiring board 52 and the like are thermally deformed, No warpage will occur. As a result, stable joining is possible and the yield can be improved. Further, heat suitable for each of the substrates 51 and 52 can be applied only for a short time, so that the tact time can be improved and the productivity can be expected to be improved. Furthermore, since the amount of heat generated can be suppressed to a minimum, it can be realized with a device having a small size and a simple structure. As a result, the size and weight of the device can be reduced.

In addition, the metal plate (A) is adjusted by adjusting the distance of the magnetic force line generating head 5 with respect to the metal plates (A) 2 and (B) 3.
2, (B) 3 by adjusting the calorific value, the metal plate (A) 2,
(B) It is also possible to switch and adjust the preheating and main heating states of 3. This enables heating and pressure bonding in various forms.

Further, as in this embodiment, the metal plate (A)
When the heat generation of the metal plates (A) 2 and (B) 3 is switched on and off by changing the distance of the magnetic field line generating head 5 to 2 and (B) 3, switches and the like are not required, and the structure is simplified. Becomes possible.

In addition, the metal plate (B) 3 for heating the rigid printed wiring board 51, which has a large thickness and requires a large heat capacity, is first heated, and then the thickness of the substrate is thin. Since the metal plate (A) 2 for heating the flexible printed circuit board 52 that requires less heat capacity than the rigid printed circuit board 51 is heated, the rigid printed circuit board 51 and the flexible printed circuit board 52 are You can add the heat you really need, respectively.

In this embodiment, the case where the rigid printed wiring board 51 and the flexible printed board 52 are joined has been described, but the present invention is not limited to this embodiment as long as they are joined by heating and pressing. Instead, it can be used in the same manner, for example, for sealing a vacuum pack of food formed of a resin film material or for wrapping a portable electric product with a resin film material. Further, in the case where a part which is inconvenient to receive the alternating magnetic field generated by the magnetic force line generation head 5 is arranged on the bonding sheet material S, a ferrite material or the like is arranged in a suitable place to protect it by magnetic shielding. It is okay to do this. Further, in the above embodiment, the case where the rigid printed wiring board 51 is set so as to face the metal plate (B) 3 and the flexible printed circuit board 52 faces the metal plate (A) 2 has been described. Depending on the structure of the joining sheet material, the rigid printed wiring board 51 is set to face the metal plate (A) 2 and the flexible printed circuit board 52 is set to face the metal plate (B) 3. It doesn't matter.

[0030]

As described above, according to the sheet material joining apparatus and method of the present invention, the metal plates sandwiching the sheet materials a and b by the eddy current generated by the high frequency magnetic force lines generated by the magnetic force line generation head. Since it is possible to heat both A and B and apply heat suitable for each sheet-shaped material from both sides of the sheet-shaped materials a and b to join them, the sheet-shaped material is thermally deformed and warped. It will not be generated. As a result, stable joining is possible and the yield and the like can be improved. Further, heat suitable for each sheet material can be applied only for a short time, so that the tact time can be improved and the productivity can be expected to be improved. Further, the structure can be simplified, and the device can be reduced in size and weight.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of a joining apparatus shown as an example of one embodiment of the present invention.

FIG. 2 is a flowchart showing an operation processing procedure of the present joining device.

FIG. 3 is a diagram for explaining a metal plate (A) used in the present joining device.

FIG. 4 is a diagram for explaining a metal plate (B) used in the present joining device.

FIG. 5 is a diagram for explaining an example of a conventional joining device.

[Explanation of symbols]

 S Bonding sheet material 1 Cradle 2 Metal plate A 3 Metal plate B 4 Holder 5 Magnetic field line generation head 6 Controller 7 Oscillation circuit 8 Motor 20 Driving means 51 Rigid printed wiring board (sheet-like material b) 52 Flexible printed wiring board ( Sheet material a)

Claims (6)

[Claims] 1. A pedestal, a magnetic force line generation head arranged above the pedestal, a drive means for reciprocating the magnetic force line generation head in a vertical direction, and supplying a predetermined high frequency current to the magnetic force line generation head. Oscillator circuit means, a metal plate A arranged on the pedestal, a metal plate A arranged to face the metal plate A, and pressed against the metal plate A side by movement of the magnetic force line generation head, A metal plate B is provided between the metal plate A and the sheet-shaped members a and b, which are placed so as to be overlapped with each other. A sheet-like material joining apparatus, wherein heat is generated in the metal plates A and B by an eddy current, and the sheet-like materials a and b are joined by the heat of the heated metal plates A and B. 2. The sheet-shaped materials a and b, wherein one sheet-shaped material a is a flexible printed wiring board and the other sheet-shaped material b is a rigid printed wiring board,
The sheet-shaped material joining apparatus according to claim 1, wherein reflow solder is disposed as a joining agent therebetween. 3. Metal plates A and B that generate heat by eddy currents generated by magnetic force lines generated by a magnetic force line generation head above and below a plurality of sheet-shaped members a and b that are placed on a pedestal so as to be stacked on each other. The metal plates A and B on which the
The sheet-shaped materials a and b are sandwiched under pressure with the sheet-shaped materials a and b by the heat of the heated metal plates A and B.
A method for joining sheet-like materials, which comprises joining between b. 4. The heat generation amount of the metal plates A and B is adjusted by changing the distance of the magnetic force line generation head to the metal plates A and B, and the preheating and main heating states of the metal plates A and B are switched. The method for joining sheet materials according to claim 3, 5. In each of the sheet-shaped materials a and b, one sheet-shaped material a is a flexible printed wiring board, and the other sheet-shaped material b is a rigid printed wiring board,
The method for joining sheet-like materials according to claim 3, wherein reflow solder is placed as a joining agent in between. 6. The method for joining sheet-like materials according to claim 3, wherein the metal plate B is heated first, and then the metal plate A is heated.