JP7217126B2 - High-frequency induction heating head and high-frequency induction heating apparatus using it - Google Patents

Description

The present invention relates to a high frequency induction heating head and a high frequency induction heating apparatus using the same.

As a method of soldering components on a circuit board, first and second core bodies are arranged above and below the circuit board, and magnetic flux is supplied to the first and second core bodies from a heating coil. , a method for soldering electronic components mounted on a circuit board has been proposed (Patent Document 1 below exists as a prior document similar to this).

Also proposed is a circuit board in which a single annular core is arranged on the surface of the circuit board and a magnetic flux is supplied to this core from a heating coil.
In this core body, a notch portion is provided in a part of the annular core body, and this notch portion is moved to a soldering place, and soldering is performed by melting the solder in this notch portion (this The following patent document 2 exists as a prior document similar to ).

JP-A-2000-42730 JP 2014-120649 A

In the former prior art, since the first and second core bodies are arranged above and below the circuit board, only the soldered portion on the circuit board sandwiched between the first and second core bodies is removed. It becomes possible to heat.
Therefore, there is an advantage that other electronic components on the circuit board are not heated carelessly.

However, other parts are mounted on the upper and lower surfaces of the circuit board, and their sizes and heights are also different. It is very difficult to move to a new location, and productivity improvement is required.
Therefore, in the latter prior art document, one core body is arranged on the surface of the circuit board, and a magnetic flux is supplied to this core body from the heating coil. It suffices to perform only the upper part, and in that respect, the workability can be improved.

However, in this latter prior art document, since the size of the notch of the core body is fixed, the core body can be replaced depending on the conditions of the soldered part, that is, the size and shape of the parts to be soldered. The need also arises, and in that respect, the improvement of productivity becomes an issue.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve productivity.

In order to achieve this object, the high-frequency induction heating head of the present invention is provided with first and second heating portions arranged opposite to each other with a space therebetween on one surface side of a circuit board. A core body and a coil that supplies magnetic flux to the first and second cores,
The first and second core bodies each have a shaft support portion and a magnetic path portion provided between the shaft support portion and the heating portion on the tip end side, and the shaft support portion of the first core body and the pivotal support portion of the second core body are overlapped, and a pivot shaft is passed through the overlapped pivotal support portion of the first core body and the pivotal support portion of the second core body, The first and second core bodies are configured to be magnetically coupled in a slidably overlapped state on the outer periphery of the rotation support shaft ,
The facing distance between the heating portion of the first core body and the heating portion of the second core body during heating is such that the distance on the tip side is smaller than the distance on the shaft supporting portion side.

As described above, the high-frequency induction heating head of the present invention includes first and second core bodies in which the heating portions provided on the front end sides of the circuit board are arranged to face each other with a gap therebetween; a coil that supplies magnetic flux to the first and second cores;
The first and second core bodies each have a shaft support portion and a magnetic path portion provided between the shaft support portion and the heating portion on the tip end side, and the shaft support portion of the first core body and the pivotal support portion of the second core body are overlapped, and a pivot shaft is passed through the overlapped pivotal support portion of the first core body and the pivotal support portion of the second core body, The first and second core bodies are magnetically coupled in a slidably overlapped state on the outer circumference of the pivot shaft , and the heating portion of the first core body and the second core body The facing distance from the heating portion during heating is such that the distance on the tip side is smaller than the distance on the shaft supporting portion side.

Therefore, if the distance between the heating portions of the first and second core bodies facing each other is also variable, it is possible to easily adapt to the shape, size, etc. of the heating portions, and there is no need to replace the high-frequency induction heating head. sexuality can be enhanced.
Further, in the present invention, the first facing distance between the heating portion of the first core body and the heating portion of the second core body during heating is a distance on the tip end side rather than the distance on the shaft supporting portion side. Since the magnetic flux is small, the magnetic flux is concentrated on the tip side of the heating portion, that is, on the wiring board side. can be melted.

1 is a perspective view of a high-frequency induction heating apparatus using a high-frequency induction heating head according to one embodiment of the present invention; FIG. It is a front view of a high frequency induction heating apparatus equally. It is a right side view of the same high frequency induction heating apparatus. It is a left side view of a high frequency induction heating apparatus equally. It is a top view of a high frequency induction heating apparatus equally. It is a perspective view which shows an example of the sample soldered using a high frequency induction heating apparatus similarly. It is a partially enlarged perspective view of the high-frequency induction heating head of the high-frequency induction heating apparatus. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a control block diagram of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a figure explaining operation|movement of the high frequency induction heating head of a high frequency induction heating apparatus equally. It is a flowchart explaining operation|movement of a high frequency induction heating apparatus equally. It is a flowchart explaining operation|movement of a high frequency induction heating apparatus equally.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1)
1 to 5 show a high-frequency induction heating apparatus, which includes a high-frequency induction heating head 1 and an XY table 2. FIG.
As an example of a wiring board, a printed wiring board 3 shown in FIG. 6 is mounted on the movable frame 2a of the XY table 2 as shown in FIGS.
Electronic components 4 are temporarily attached to the lower surface of the printed wiring board 3 used in this embodiment with an adhesive (not shown), and as shown in FIG. The through hole 6 provided in the substrate 3 is penetrated from the bottom to the top, and the tip thereof protrudes upward from the printed wiring board 3 .

Also, lands 7 for soldering are provided with copper or the like in the through holes 6 of the printed wiring board 3 shown in FIG. ing.
Further, the lands 7 are pre-applied with cream solder.

In this embodiment, as shown in FIGS. 1 to 5, on the upper surface side of the printed wiring board 3, the terminal 5 of the electronic component 4 and the cream solder of the land 7 are heated by the high-frequency induction heating head 1 to obtain cream solder. Solder is melted and part of it flows into the through hole 6, thereby electrically and mechanically connecting the terminal 5 of the electronic component 4 to the land 7 part and the through hole 6. .

As shown in FIGS. 1 to 5, the high-frequency induction heating head 1 for performing such soldering has core bodies 8 and 9 made of a soft magnetic material such as ferrite.
The core bodies 8 and 9 are each C-shaped and are combined with their open sides facing each other.

Specifically, the core body 8 has a shaft support portion 8a in the upper portion, a magnetic path portion 8b in the middle portion, and a heating portion 8c in the lower portion.
Similarly, the core body 9 has a shaft support portion 9a in the upper portion, a magnetic path portion 9b in the middle portion, and a heating portion 9c in the lower portion.

Then, these core bodies 8 and 9 are combined with their opening sides facing each other as described above.
At this time, the shaft support portions 8a and 9a of the core bodies 8 and 9 are overlapped with each other, and in this state, through holes (not shown) provided in the respective shaft support portions 8a and 9a are inserted with the holes shown in FIGS. As shown, the pivot shaft 10 is passed through.
That is, the core bodies 8 and 9 are rotatably supported around the rotation support shaft 10 .

The description of the core bodies 8 and 9 continues.
These core bodies 8 and 9 are formed of plate-like bodies, and the cross-sectional area in the plate thickness direction (the area of the cross section existing there when cut in the plate thickness direction) in the heating portions 8c and 9c is , the magnetic path portions 8b and 9b and the axial support portions 8a and 9a.

That is, as shown in FIGS. 11 and 12, when the high-frequency induction heating head 1 heats the terminals 5 of the electronic component 4 and the cream solder of the lands 7 to melt the cream solder, the core body 8, The heating portions 8c, 9c of 9 are brought close to both sides of the terminal 5 (non-contact state). It is preferable that the heating portions 8c and 9c of 9 be miniaturized (the cross-sectional area in the plate thickness direction is reduced).

On the other hand, the magnetic path portions 8b and 9b and the shaft support portions 8a and 9a have a cross-sectional area in the plate thickness direction (the cross section existing there when cut in the plate thickness direction) so that the magnetic flux can easily pass. area) of the heating portions 8c and 9c in the plate thickness direction (the area of the cross section existing there when cut in the plate thickness direction).

In addition, the cross-sectional area in the plate thickness direction in the vicinity of the shaft support portions 8a and 9a (the area of the cross section existing there when cut in the plate thickness direction) is defined as It is made larger than the cross-sectional area (the area of the cross section existing there when cut in the plate thickness direction).
This is because, even when the core bodies 8 and 9 perform opening and closing operations, the magnetic flux flows between the shaft support portions 8a and 9a through the gaps present in the overlapping and sliding portions. , 9a to facilitate the flow of magnetic flux between the shaft support portions 8a and 9a and prevent the magnetic flux from concentrating on a portion of the shaft support portions 8a and 9a.

Considering such a thing, the distance of the gap (second gap) existing in the overlapping portion of the shaft support parts 8a and 9a is set to the distance (first gap) existing between the heating parts 8c and 9c during heating. , so that the magnetic coupling at the shaft supports 8a and 9a is effectively performed.

In addition, since the core bodies 8 and 9 are formed of plate-like bodies, this part can be described in another expression as follows.
That is, when the core body 8 is viewed from above, the axial support portion 8a has a larger plane area than the magnetic path portion 8b and the heating portion 8c.

Further, when the core body 9 is viewed from above, the axial support portion 9a has a larger planar area than the magnetic path portion 9b and the heating portion 9c.
2 and 11, the core members 8 and 9 are opened and closed, so that the shaft support portions 8a and 9a always have a large area and a small area. As a result, the magnetic resistance between the shaft supports 8a and 9a is small, and the magnetic flux is effectively transferred.

Referring back to FIGS. 1 to 5, the configuration for opening and closing the core bodies 8 and 9 will be described.
One end of a pivot shaft 10 that opens and closes (rotates) the core bodies 8 and 9 is fixed to the lower vertical surface of the base 11 so as to be horizontal to the XY table 2 .

A motor 12 is fixed to the upper horizontal surface of the base 11 . Since this motor 12 is a general stepping motor such as that disclosed in Japanese Unexamined Patent Application Publication No. 2016-59170, a brief description will be given to avoid complication of the description.
In other words, as described in Japanese Patent Application Laid-Open No. 2016-59170, a male thread is formed on the shaft of the internal rotor magnet, and the moving body 13 that moves up and down is screwed to the male thread of this shaft. .

A lower end of the moving body 13 is connected to a connecting portion 14 arranged above the core bodies 8 and 9 .
Link mechanisms 15 and 16 are connected to the connecting portion 14 so as to face each other in the left-right direction shown in FIG.
The link mechanisms 15 and 16 have a well-known structure and are composed of two bent plates. , are fixed to the shaft support portions 8a, 9a of the core bodies 8, 9 by claws.

With the above configuration, by rotating the motor 12 forward or backward, the moving body 13 is moved up and down, the connecting part 14 is also moved up and down, and the bending state of the link mechanisms 15 and 16 is varied, whereby the core body The heating portions 8c and 9c of 8 and 9 are opened and closed.
That is, as shown in FIG. 20, when the terminal 5 of the electronic component 4 is thin, the heating portions 8c and 9c of the core bodies 8 and 9 are brought close to each other (the gap between the heating portions 8c and 9c is narrow). As shown in 21, when the terminal 5 of the electronic component 4 is thick, the heating portions 8c and 9c of the core bodies 8 and 9 are wider than in FIG. 20 (the gap between the heating portions 8c and 9c is widened). .

Next, vertical movement of the core bodies 8 and 9 will be described.
The base body 11 supporting the core bodies 8 and 9 and the motor 12 is connected to a vertical movement mechanism 17, and the core bodies 8 and 9 are also moved up and down by moving the base body 11 up and down by the vertical movement mechanism 17. FIG.

The vertical movement mechanism 17 rotates a shaft 18 having a helical groove on its outer periphery forward or backward by a motor 19 to vertically move a connecting body 20 threadedly connected to the outer periphery of the shaft 18 . The core bodies 8 and 9 are moved up and down by moving the base 11 fixed to the base 11 up and down.

It should be noted that the motor 19 is also a common stepping motor as disclosed in Japanese Patent Laid-Open No. 2016-59170, for example.

This motor 19 is different from the motor 12 described above in that the shaft 18 is connected to the shaft of the internal rotor magnet. That is, the shaft 18 is configured to rotate.
A support shaft 21 is also provided in parallel with the shaft 18 in order to smoothly move the connecting body 20 up and down. It will move up and down in the state where it is held.

Next, the coil 22 for supplying magnetic flux to the core bodies 8 and 9 will be explained.
The coil 22 has a pipe shape for circulating cooling water therein, and is supplied with a current of 1 MHz and 100 A, for example.
Therefore, in order to stably supply the cooling water, the coil 22 is fixed above the XY table 2 as shown in FIGS. The movable frame 2a of the XY table 2 and the core bodies 8 and 9 are moved.

FIG. 13 shows a state in which the core bodies 8 and 9 are lowered by the XY table 2 while the soldering terminals 5 of the printed wiring board 3 of FIG.
11, the coil 22 must be present between the core bodies 8 and 9 during soldering, so the heating portions 8c and 9c are opened as shown in FIGS. In this state, the core bodies 8 and 9 are lowered from above.

20 and 21, the core bodies 8 and 9 are closed as shown in FIG. 15 to the gap between the heating portions 8c and 9c corresponding to the thickness and shape of the terminal 5 to be heated Thereafter, as shown in FIGS. 15 and 16, the core bodies 8 and 9 are lowered to the terminal 5 positions described in FIGS.

In this state, the coil 22 is energized, and on the upper surface side of the printed wiring board 3, the terminal 5 of the electronic component 4 and the cream solder of the land 7 are heated by the high-frequency induction heating head 1, and the cream solder of the land 7 is heated. is melted and part of it also flows into the through hole 6 , thereby electrically and mechanically connecting the terminal 5 of the electronic component 4 with the land 7 inside the through hole 6 .

Next, the energization of the coil 22 is stopped, and the core bodies 8 and 9 are raised in the closed state as shown in FIGS. 17 and 18 .
In this embodiment, as shown in FIG. 6, there are a plurality of terminals 5 having the same shape to be heated. Therefore, in FIGS. , the core bodies 8 and 9 are raised to a state where the coil 22 exists between the core bodies 8 and 9 .

In FIG. 18, in this state, the XY table 2 next moves the terminal 5 to be heated below the heating portions 8c and 9c, and then moves the core bodies 8 and 9 to the position of the terminal 5 as shown in FIG. lower to.
In this state, the coil 22 is energized, and the cream solder of the terminal 5 of the electronic component 4 and the land 7 is heated by the high-frequency induction heating head 1 on the upper surface side of the printed wiring board 3 to melt the cream solder. , part of it also flows into the through hole 6 , thereby electrically and mechanically connecting the terminal 5 of the electronic component 4 to the land 7 and the through hole 6 .
15 to 19 are repeated to solder all the terminal 5 portions shown in FIG.
FIG. 10 shows the control circuit.

A motor (M1) 12 for opening and closing the core bodies 8 and 9 and a motor (M2) 19 for vertically moving the core bodies 8 and 9 are connected to a control section 23 .
The X-axis motor (M3) 24 and the Y-axis motor (M4) 25 of the XY table 2 , timer 26 and memory 27 are also connected to the controller 23 .
Furthermore, the coil 22 is connected to the controller 23 via an inverter 28 .
The motors 24 and 25 of the XY table 2 are also stepping motors.

A stepping motor, as is well known in, for example, Japanese Unexamined Patent Application Publication No. 2016-59170, is rotated by an angle unique to the stepping motor in both the forward and reverse directions each time a pulse is applied. In this embodiment as well, the control is accurate and simple, so it is adopted.

Another reason for using stepping motors as the motors 12, 19, 24, and 25 is that the current position can be detected using a photointerrupter, a microswitch, or the like.
Positional information for controlling the motors 12, 19, 24 and 25 are stored in the memory 27 together with the operation programs shown in FIGS.

The operation of the above configuration will be explained.
First, the XY table 2 is driven by the controller 23 .
6 is stored as position information in the memory 27, the printed wiring board 3 is moved to the position shown in FIG. is moved (S1, S2 in FIG. 22).

When the printed wiring board 3 is moved to a fixed position, the motor 19 lowers the core bodies 8 and 9 from above while the heating portions 8c and 9c are opened as shown in FIGS. of S3).
When the core bodies 8 and 9 descend to the fixed position (the position information is stored in the memory 27) shown in FIG. 14, the motor 12 performs the operation of closing the core bodies 8 and 9 (S4 and S5 in FIG. 22).

As shown in FIG. 15, the gap position (positional information is stored in the memory 27) between the heating portions 8c and 9c corresponding to the thickness and shape of the terminal 5 to be heated, described in FIGS. When 8 and 9 are closed, core bodies 8 and 9 are lowered by motor 19 (S6 in FIG. 22, S7 in FIG. 23).

As shown in FIG. 16, when the core bodies 8 and 9 are lowered to the terminal 5 position (the position information is stored in the memory 27) explained in FIGS. (S8, S9 in FIG. 23).

When it is determined by the timer 26 that the energization time has ended, the energization of the coil 22 is stopped (S10 to S12 in FIG. 23).

7 to 9 illustrate the heating operation by energizing the coil 22. FIG.
In this embodiment, as shown in FIGS. 7 to 9, the opposing distance between the heating portion 8c of the core body 8 and the heating portion 9c of the core body 9 during heating is the distance on the side of the shaft support portions 8a and 9a. The distance (T2) on the tip side (printed wiring board 3 side) is made smaller than (T1).
Therefore, as shown in FIG. 8, the magnetic flux is concentrated on the tip side of the heating portions 8c and 9c, that is, on the side of the printed wiring board 3. As a result, the terminals 5 of the electronic component 4 and the lands 7 is effectively heated for a short period of time to melt the cream solder, and a part of the melted solder also flows into the through hole 6, thereby connecting the terminal 5 of the electronic component 4 to the land 7 and the through hole 6 can be electrically and mechanically connected.

In addition, in the present embodiment, on the tip side (printed wiring board 3 side) of at least one of the heating portions 8c and 9c of the core bodies 8 and 9, tip magnetic flux expanding toward the tip side is provided inside each of them. Reinforcement portions 8d and 9d are provided. More specifically, as shown in FIG. 7, the heating portions 8c and 9c are projected downward (on the side of the printed wiring board 3 and opposite to the shaft support portions 8a and 9a). , the opposing area is increased and a sufficient magnetic path can be formed to the lower end side. In this state, a sufficient magnetic path is formed up to the lower end, and in this state, as described above, tip magnetic flux strengthening portions 8d and 9d are provided inside each of them so as to widen the angle toward the tip side. ing.

The tip magnetic flux enhancing portions 8d and 9d are also called so-called C end surfaces on the tip side (printed wiring board 3 side) of the heating portions 8c and 9c. As shown in FIG. 9, the amount of magnetic flux directed toward the land 7 increases, and the solder previously applied to the land 7 melts in a short period of time and easily flows into the through hole 6 of the printed wiring board 3. As a result, the reliability of electrically and mechanically connecting the terminals 5 of the electronic component 4 to the lands 7 and the through holes 6 is improved.

By providing the tip magnetic flux strengthening portions 8d and 9d, the solder previously applied to the land 7 melts in a short time and easily flows into the through hole 6 of the printed wiring board 3. A clear reason for this point has not been fully elucidated at present, but a large amount of magnetic flux also flows through the solder on the land 7, causing the solder to melt. It is thought that this is because a fluid state also occurs in itself.

When the soldering of the terminal 5 to the land 7 is completed as described above, the motor 19 moves the core bodies 8 and 9 to the fixed position shown in FIG. memory) (S13, S14 in FIG. 23).
Next, as shown in FIG. 6, in this embodiment, there are a plurality of terminals 5 to be soldered. Therefore, as shown in FIGS. Moreover, the core bodies 8 and 9 are raised until the coil 22 exists between the core bodies 8 and 9. In this state, the printed wiring board 3 is moved by the XY table 2, and thereafter, as shown in FIG. As shown in FIG. 23, the core bodies 8 and 9 are lowered, and the next terminal 5 is soldered (S16, S17, S7 to S12 in FIG. 23).

When all the soldering is completed, in S15 there is no place to solder next, so the heating portions 8c and 9c of the core bodies 8 and 9 are opened as shown in FIG. Then, the core bodies 8 and 9 are lifted and the operation is stopped (S15, S18-S22 in FIG. 23).

INDUSTRIAL APPLICABILITY The present invention is used, for example, for soldering components to printed wiring boards.

1 high-frequency induction heating head 2 XY table 2a movable frame 3 printed wiring board 4 electronic component 5 terminal 6 through hole 7 land 8 core body 8a shaft support portion 8b magnetic path portion 8c heating portion 8d tip magnetic flux strengthening portion 9 core body 9a shaft support portion 9b Magnetic path portion 9c Heating portion 9d Tip magnetic flux enhancing portion 10 Rotating support shaft 11 Base 12 Motor 13 Moving body 14 Connecting portion 15 Link mechanism 16 Link mechanism 17 Vertical movement mechanism 18 Shaft 19 Motor 20 Connecting body 21 Support shaft 22 Coil 23 Control Part 24 Motor 25 Motor 26 Timer 27 Memory 28 Inverter

Claims (6)

first and second core bodies, on one side of the circuit board, in which the heating portions provided on the tip sides thereof are arranged to face each other with a gap therebetween ;
a coil that supplies magnetic flux to the first and second cores,
The first and second core bodies each have a shaft support portion and a magnetic path portion provided between the shaft support portion and the heating portion on the tip end side, and the shaft support portion of the first core body and the pivotal support portion of the second core body are overlapped, and a pivot shaft is passed through the overlapped pivotal support portion of the first core body and the pivotal support portion of the second core body, The first and second core bodies are configured to be magnetically coupled in a slidably overlapped state on the outer periphery of the rotation support shaft ,
The high-frequency wave according to claim 1, wherein the opposing distance between the heating portion of the first core body and the heating portion of the second core body during heating is smaller on the tip side than the distance on the shaft supporting portion side. induction heating head. Each of the first and second core bodies is formed of a plate-like body, and the cross-sectional area in the thickness direction of each of the first and second core bodies in the vicinity of the respective shaft supports is defined by each magnetic path. 2. The high-frequency induction heating head according to claim 1, wherein the cross-sectional area in the thickness direction of the portion is larger than that of the plate thickness direction. Each of the first and second core bodies is formed of a plate-like body, and the cross-sectional area in the thickness direction of each heating portion of each of the first and second core bodies is 3. The high-frequency induction heating head according to claim 1, wherein the cross-sectional area in the plate thickness direction of , and the cross-sectional area in the plate thickness direction of each magnetic path portion are smaller. 4. The method according to any one of claims 1 to 3, wherein a front end magnetic flux strengthening portion is provided on the front end side of at least one of the heating portions of the first and second core bodies, the angle of which is widened toward the front end side. High frequency induction heating head. 3. The heating portion of said first and second core bodies has a projecting shape directed to the side opposite to the shaft supporting portion, and a tip magnetic flux strengthening portion is provided on the tip side thereof so as to widen the angle toward the tip side. 5. The high-frequency induction heating head according to 4. A high-frequency induction heating head according to any one of claims 1 to 5, wherein a part of said coil is arranged in a portion surrounded by said first and second core bodies.

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