JP7601429B2 - Heating device, soldering method and welding method using the same - Google Patents

Description

The present invention relates to a heating device and a heating method used in soldering, welding, semiconductor processes, etc.

Conventionally, soldering methods for mounting electronic components on a circuit board have been the flow method, in which molten solder is sprayed onto the solder surface of the board, and the reflow method, in which cream solder that has been applied in advance to the "land" part to be soldered is melted in a reflow furnace to join the parts.
In recent years, from the viewpoint of energy conservation, a method has been introduced in which, in combination with a robot, only the parts to be soldered are heated, instead of the entire board. For example, a method of heating with a soldering iron (Patent Document 1) and a method of reflowing only the parts to be soldered by laser heating (Patent Document 2) are known. These methods, in combination with a robot, can flexibly respond to changes in the soldering target and can be used for multi-product production.

Meanwhile, welding methods that have been used include arc welding (Patent Document 3), which generates an arc between the base material and a welding rod or electrode, gas welding, which uses the heat of a gas flame, and spot welding (Patent Document 4), which clamps the base material between two electrodes and applies localized heat and pressure by passing an electric current through it. However, from the perspective of saving energy and electricity, laser welding (Patent Document 5), which uses heat from laser irradiation to weld, has also been introduced, and automation is being attempted in combination with robots.

Japanese Patent Application Laid-Open No. 8-18215 Japanese Patent Application Laid-Open No. 2-92452 Patent Publication No. 2021-094581 JP 2022-100858 A JP 2018-183799 A

However, the method of combining a robot with localized laser irradiation for soldering or welding, while being flexible and able to handle small-lot, high-mix production, has the problem of high costs for laser light sources, etc.

The present invention aims to solve the above problems, provide a heating device and heating method that can flexibly accommodate changes in the soldering and welding objects and can be used for energy-saving and inexpensive soldering and welding.

In order to solve the above problems, the heating device of the present invention is a heating device used for soldering or welding,
one or more spot lamp heaters including a heating lamp and focusing optics;
an articulated robot for controlling the position and direction of the spot lamp heater;
Including,
The light emitted from the heating lamp of the spot lamp heater is focused to a predetermined spot size by the focusing optical system and irradiated onto an object to heat it.

The heating lamp is preferably a halogen lamp or a xenon lamp.

The heating device may be configured to have a plurality of spot lamp heaters with different spot sizes at the focus of the focusing optical system, so that different spot lamp heaters can be used depending on the heating location.

A shutter may be further provided to open and close the optical path of the light emitted from the spot lamp heater, and the exposure time to the heated area may be controlled by opening and closing the shutter.

The apparatus may further include a fixing table for fixing the object, and the fixing table may be provided with a preheater for preheating the object.

The apparatus may further include a chamber that seals the object fixed to the fixing table and has a transparent window, an exhaust pipe for exhausting the inside of the chamber, and a purge pipe for introducing a purge gas into the inside of the chamber, and the light emitted from the spot lamp heater is irradiated onto the object through the transparent window of the chamber, and the inside of the chamber may be configured to be able to be exhausted.

The soldering method of the present invention involves applying solder to the land portion of an electronic board in advance, placing electronic components on the board, and then heating the solder using the heating device described above to reflow the soldering.

The welding method of the present invention involves heating and welding the butt joint between the workpieces to be welded together using the heating device described above.

According to the present invention, by adopting a spot lamp heater including an inexpensive heating lamp, it is possible to realize high temperatures that allow spot soldering and welding, and by combining it with an articulated robot, it is possible to flexibly respond to changes in the soldering and welding objects, and it is possible to provide an energy-saving and inexpensive heating device.

1 is a conceptual diagram showing a heating device according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing a spot lamp heater of the heating device of FIG. 1 . 2 is a conceptual diagram showing a shutter portion of the heating device of FIG. 1. FIG. 2 is a conceptual diagram showing an initial state of the heating device of FIG. 1 . FIG. 2 is a conceptual diagram showing a state in which the heating device of FIG. 1 has received an object. FIG. 2 is a conceptual diagram showing a state in which the heating device of FIG. 1 fixes an object. FIG. 2 is a conceptual diagram showing a state in which the heating device of FIG. 1 seals an object. 2 is a conceptual diagram showing a state in which the heating device of FIG. 1 irradiates an object with emitted light. 2 is a conceptual diagram showing a state in which the heating device of FIG. 1 irradiates an object with emitted light.

Heating device 1, which is an embodiment of the present invention, will be described below with reference to Figures 1 to 4F. As shown in Figure 1, heating device 1 includes two spot lamp heaters 10, a shutter 20, an articulated robot 30, a fixed base 40, a chamber 50, an exhaust pipe 60, a purge pipe 65, and a control unit 70.

As shown enlarged in FIG. 2, the spot lamp heater 10 is a light source unit that includes a halogen lamp (heating lamp) 11 and a collecting mirror (collecting optical system) 12, and collects the light emitted from the halogen lamp 11 to a predetermined spot size by the collecting mirror 12 and irradiates the target object 80 (see FIG. 1).
The halogen lamp 11 is a lamp in which a small amount of halogen gas is introduced in addition to an inert gas inside the bulb to achieve high output and long life. Commercially available lamps of, for example, 150 W to 2 kW can be used.

The focusing mirror (focusing optical system) 12 is a mirror with a roughly elliptical spherical shape, formed, for example, by mirror-finishing metal or coating glass with metal, and focuses the light emitted from the halogen lamp 11. When the filament of the halogen lamp 11 is placed at one focus f0 of the elliptical spherical surface E, the light is focused at the other focus f1 of the elliptical spherical surface E. A maximum temperature of about 1500°C can be obtained near this focus f1, making soldering and welding possible. The spot size is, for example, about Φ5 mm near the focus f1, and this "spot size at the focus" is thought to be determined by the size of the lamp filament. The spot size increases the farther away from the focus f1 in the optical axis direction, so the spot size on the target 80 can be adjusted by adjusting the position of the spot lamp heater 10 in the optical axis direction. However, there is an advantage in that the spot size is stabilized if the position of the spot lamp heater 10 is adjusted so that the target 80 is near the focus f1.

The heating device 1 of this embodiment has two spot lamp heaters 10a, 10b having different spot sizes at the focus f1 of the focusing mirror (focusing optical system) 12, so that different spot lamp heaters 10a, 10b can be used depending on the heating location.
With this configuration, a spot lamp heater with an appropriate spot size can be selected and used, so that it can be flexibly adapted to cases where the size of the heating spot varies depending on the object to be soldered or welded and the heating spot.
In this embodiment, the light collecting optical system is the light collecting mirror 12, but a light collecting lens may be used, or a light collecting mirror and a light collecting lens may be combined.
The spot lamp heater 10 including the halogen lamp 11 and the condenser mirror 12 may be a commercially available product.

3, the shutter 20 is attached to the emission side of each spot lamp heater 10 and opens and closes the optical path of the emitted light, and the exposure time to the heated area can be controlled by turning on and off this shutter 20. In this embodiment, an air-driven rotary actuator 21 moves the rotational position of shutter blades 22 to close and open the optical path of the emitted light.
This configuration enables faster control than turning on and off the halogen lamps (heating lamps) 11 of the spot lamp heaters 10, and ensures that only the required area is heated.

The articulated robot 30 is a robot that controls the position and direction of the spot lamp heater 10 .
1, the articulated robot 30 has a base 31 and a robot arm 32 having three bending joints J1 to J3 and three torsion axes T1 to T3, and is a robot that can be controlled along six axes and is capable of performing a variety of operations. Two spot lamp heaters 10a, 10b and their respective shutters 20 are attached to a tip 32a of the robot arm 32.
This articulated robot 30 may be a commercially available one, and can be taught its movements using dedicated control software, and can repeatedly execute the movements that have been taught. With this configuration, the articulated robot 30 can perform a variety of movements through teaching, etc., and can therefore flexibly accommodate changes in the soldering and welding objects.
However, this articulated robot 30 does not necessarily have to have six axes, and may have any number of axes equal to or greater than two.

The fixing table 40 is a jig for placing the object 80, and includes, for example, a base 41, a clamping mechanism 42 for clamping the object 80, and a lift pin 43 for lifting the object 80 to facilitate the loading and unloading of the object 80, as shown in FIG. 1, so that the object 80 to be soldered or welded can be fixed on the base. However, as a fixing means, vacuum suction or magnetic suction may be used instead of the mechanical clamping mechanism 42 shown in the figure. Also, depending on the structure of the transport mechanism for the object 80 and the transport method (e.g., manual), the lift pin 43 may not necessarily be provided. Also, if the bottom surface of the object 80 (the surface that contacts the base 41) is uneven, heating the object 80 directly will cause uneven heating, so the lift pin 43 may be protruded from the base 41 to an extent (0.1 to 3.0 mm) that the unevenness of the bottom surface of the object 80 does not touch the base 41, and the object 80 may be heated by floating it, making it compatible with a proximity heating method. At this time, the clamp mechanism 42 is not used.
In this embodiment, a preheater 44 for preheating the object 80 is provided inside the base 41 of the fixing table 40. The temperature of the fixing table 40 is monitored by a temperature sensor (not shown), and the output of the preheater 44 is adjusted so that this temperature becomes a set temperature.
With this configuration, the object 80 can be preheated, so that soldering or welding can be performed quickly even with a small amount of irradiation energy from the spot lamp heater 10.

In this embodiment, in order to seal the object 80 in cooperation with the chamber 50 described later, the fixed base 40 is attached to a lifting mechanism 45 consisting of a motor and a feed screw, and is capable of moving between an elevated position in close contact with the chamber 50 and a lowered position away from the chamber 50 to enable the object 80 to be loaded and unloaded manually or by an external transport robot (not shown).
However, this configuration is not limited to the above, and a structure in which the fixed base 40 is fixed and the chamber 50 is raised and lowered may also be used, or the fixed base 40 and the chamber 50 may be fixed, and a door for loading and unloading may be provided on the chamber 50, and the object 80 may be loaded and unloaded through this door.

The chamber 50 is a container that seals the object 80 placed on the fixed stage 40, and is intended to insulate the object 80 from the surrounding atmosphere while it is being heated. As shown in FIG. 1, the chamber 50 has a transparent window 51 made of quartz, and the light emitted from the spot lamp heater 10 can pass through this transparent window 51 and be irradiated onto the object 80.

The chamber 50 is provided with an exhaust pipe 60 connected to an external exhaust pump (not shown) for exhausting the inside, and a purge pipe 65 connected to an external purge gas source (not shown) for introducing a purge gas into the chamber 50. This "purge gas" is air or an inert gas such as _N2 . The exhaust pipe 60 and the purge pipe 65 are provided with opening and closing valves 61, 66, respectively, and are configured to, for example, exhaust the purge gas while purging it during heating of the object 80, thereby removing outgassing from soldering or welding.
With this configuration, soldering or welding can be performed in a vacuum or in an inert gas atmosphere, and the outgassing that occurs can be exhausted, thereby improving the quality of the soldering or welding.

The control unit 70 has a processor (not shown) and driver circuits (not shown) for each unit, and performs ON-OFF control of the two spot lamp heaters 10a, 10b, opening and closing control of each shutter 20, drive control of the articulated robot 30, drive control of the clamp mechanism 42, lift pin 43 and lifting mechanism 45 of the fixed base 40, and opening and closing control of each opening and closing valve 61, 66 of the exhaust pipe 60 and purge pipe 65, as well as being configured to communicate with an external transfer robot (not shown) to load and unload the object 80.

Next, an example of the operation of the heating device 1 of the present invention configured in this manner will be described with reference to Figures 4A to 4F. In this example, the heating device 1 is configured as a reflow soldering device, and is configured to solder a plurality of soldering points, including a first soldering point P1 that requires a first heating energy and a second soldering point P2 that requires a second heating energy.

4A, in the initial state, the fixed table 40 is in a lowered position spaced downward from the chamber 50, the lift pins 43 of the fixed table 40 are in an elevated position, the clamp mechanism 42 is in a released state, and no target object 80 is placed on the fixed table 40. However, in order to stabilize the temperature of the fixed table 40, the preheater 44 is continuously turned on in advance.
The control unit 70 communicates with an external transfer robot (not shown), and the transfer robot carries in the target object 80 and places it on the lift pins 43 as shown in Fig. 4B. This target object 80 is a circuit board 81 to be soldered, on which electronic components 82a and 82b are placed. Cream solder has been applied to each land (not shown) of the circuit board 81 in advance.

When the control unit 70 confirms through a sensor (not shown) that the object 80 has been placed on the lift pins 43, it lowers the lift pins 43 and activates the clamping mechanism 42 to clamp the object 80, as shown in FIG. 4C.
Next, the control unit 70 drives the lifting mechanism 45 to raise the fixed table 40 and bring it into close contact with the lower surface of the chamber 50, as shown in FIG. 4D, thereby sealing the target object 80.
Furthermore, the control unit 70 opens the on-off valve 61 of the exhaust pipe 60 and the on-off valve 66 of the purge pipe 65 to exhaust the purge gas into the chamber 50 while purging it.

Next, the control unit 70 drives the articulated robot 30 to cause the articulated robot 30 to execute the operation that has been taught to the articulated robot 30 in advance.
Specifically, first, the robot arm 32 of the articulated robot 30 is adjusted so that the first spot lamp heater 10a is positioned and oriented so as to irradiate the first soldering point P1 of the object 80. When the control unit 70 receives a report from the articulated robot 30 that this positioning has been completed, as shown in Fig. 4E, the control unit 70 energizes the first spot lamp heater 10a to turn it on, and further opens the shutter 20 for the first spot lamp heater 10a to irradiate the emitted light through the transparent window 51 to the first soldering point P1. This melts the cream solder applied to the land of the circuit board 81, and the electronic component 82a is soldered to the circuit board 81. After a predetermined time has elapsed, the shutter 20 is closed, and the first spot lamp heater 10a is de-energized to turn it off.
Next, the robot arm 32 of the articulated robot 30 is adjusted so that the second spot lamp heater 10b is positioned and oriented so as to irradiate the second soldering point P2 of the object 80. When the control unit 70 receives a report from the articulated robot 30 that this positioning has been completed, as shown in FIG. 4F, the control unit 70 energizes the second spot lamp heater 10b to turn it on, and further opens the shutter 20 for the second spot lamp heater 10b to irradiate the emitted light through the transparent window 51 to the second soldering point P2. This melts the cream solder applied to the land of the circuit board 81, and the electronic component 82b is soldered to the circuit board 81. After a predetermined time has elapsed, the shutter 20 is closed, and the second spot lamp heater 10b is de-energized to turn it off.

By repeating this operation, when soldering of each soldering point is completed, the control unit 70 closes the opening/closing valve 61 of the exhaust pipe 60, confirms with a pressure sensor (not shown) that the pressure inside the chamber 50 has reached atmospheric pressure, closes the opening/closing valve 66 of the purge pipe 65, and lowers the fixing table 40 as shown in FIG. 4C.
Next, as shown in FIG. 4B, the control unit 70 releases the clamp mechanism 42, raises the lift pins 43, and communicates with an external transfer robot (not shown), which then removes the target object 80.

When welding is performed using heating device 1, the operation is the same as that of soldering described above, except that the heated area is the butt joint between the workpieces to be welded instead of the soldering area, and the applied radiation energy is also different.

According to this embodiment, by adopting a spot lamp heater 10 including an inexpensive heating lamp 11, it is possible to realize a high temperature that allows spot soldering and welding, and by combining it with an articulated robot 30, it is possible to flexibly respond to changes in the object 80 to be soldered or welded, and an energy-saving and inexpensive heating device can be provided.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to these specific examples, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

For example, in the above embodiment, a halogen lamp is used as the heating lamp 11, but a xenon lamp, for example, may also be used.

The heating device 1 of the above embodiment has two spot lamp heaters 10a, 10b with different spot sizes at the focus f1 (see FIG. 2) of the focusing optical system 12, but may have three or more spot lamp heaters 10, or may have only one spot lamp heater 10.

The heating device 1 of the above embodiment is equipped with a shutter 20 that blocks and opens the light emitted from each spot lamp heater 10, but depending on the response time required during heating, the shutter 20 may not be provided.

In addition, the heating device 1 in the above embodiment is provided with a fixed base 40 and a preheater 44, but it may be provided with a fixed base 40 without a preheater 44, or with a fixing mechanism other than the fixed base 40.

The heating device 1 of the above embodiment includes a chamber 50 that seals the object 80, has a transparent window 51 through which the emitted light passes, and is configured so that the inside can be evacuated, but depending on the object 80 and heating conditions, this chamber 50 may not be provided.

The heating device of the present invention can be widely used in industrial fields where soldering and welding are performed.

1: Heating device 10: Spot lamp heater 10a: First spot lamp heater 10b: Second spot lamp heater 11: Halogen lamp (heating lamp)
12: Condenser mirror (condenser optical system)
20: Shutter 21: Rotary actuator 22: Shutter blade 30: Articulated robot 31: Base 32: Robot arm 32a: Tip 40: Fixed base 41: Base 42: Clamp mechanism 43: Lift pin 44: Preheater 45: Lifting mechanism 50: Chamber 51: Transparent window 60: Exhaust pipe 61: Opening/closing valve 65: Purge pipe 66: Opening/closing valve 70: Control unit 80: Object 81: Circuit boards 82a, 82b: Electronic component E: Ellipsoidal surfaces J1-J3: Bending joint P1: First soldering point P2: Second soldering point T1-T3: Axes f0, f1: Focus

Claims (7)

A heating device for use in soldering or welding, comprising:
one or more spot lamp heaters including a heating lamp and focusing optics;
an articulated robot for controlling the position and direction of the spot lamp heater;
Including,
A heating device comprising: a light collecting optical system that collects light emitted from the heating lamp of the spot lamp heater to a predetermined spot size and irradiates and heats an object;
A heating device comprising a plurality of spot lamp heaters each having a different spot size at the focus of the light collecting optical system, and capable of using different spot lamp heaters depending on the location to be heated . The heating device according to claim 1, wherein the heating lamp is a halogen lamp or a xenon lamp. The heating device according to claim 1, further comprising a shutter for opening and closing the optical path of the light emitted from the spot lamp heater, and the exposure time of the heating area can be controlled by opening and closing the shutter. The heating device according to claim 1, further comprising a fixing table for fixing the object, the fixing table being provided with a preheater for preheating the object. 5. The heating device according to claim 4, further comprising: a chamber for sealing the object fixed to the fixing table and having a transparent window; an exhaust pipe for exhausting the inside of the chamber; and a purge pipe for introducing a purge gas into the inside of the chamber, wherein light emitted from the spot lamp heater is irradiated onto the object through the transparent window of the chamber, and the inside of the chamber is configured to be able to be exhausted. 13. A soldering method comprising the steps of: applying solder to a land portion of an electronic board in advance; placing an electronic component thereon; and heating the solder using the heating device according to claim 1 to perform reflow soldering. A welding method for heating and welding a butted portion of workpieces to be welded together using the heating device according to claim 1 .

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