JP2009140804A - High frequency heating device, and object to be heated - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that in a conventional high frequency heating device, temperatures of each of objects to be heated and temperatures in various points of the objects become uneven while the objects are heated repeatedly by induction heating. <P>SOLUTION: In the high frequency heating device 10, an AC magnetic field is generated by conducting an AC current to an induction coil 11 and the object 17 placed in the generated AC current field is caused to generate heat. An outer surface of the object 17 is covered by a coating film 19 composed of a material which has no change in a radiation ratio ε even if it is heated up to a heat generating temperature of the object 17. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a high-frequency heating apparatus configured to generate an alternating magnetic field by passing an alternating current through an induction coil and to generate heat from a heat generating body disposed in the generated alternating magnetic field, and the heat generating body.

In general, when a semiconductor device is configured by mounting a large number of electronic components such as semiconductor elements on a circuit board, the circuit board is heated with the solder interposed between the circuit board and the electronic component, The electronic component is mounted on the circuit board by melting the substrate.
When the circuit board is heated in this way, a high-frequency heating apparatus that performs heating using an induction heating phenomenon may be used.

In other words, the high-frequency heating device generates an alternating magnetic field by passing an alternating current through the induction coil, generates an alternating current in a heat generating body (susceptor) disposed in the generated alternating magnetic field, and the alternating current causes the object to be covered. The heating element generates heat, and by placing the circuit board on the heat generating body, heat generated from the heat generating body is conducted to the circuit board to heat the circuit board. .
As a high-frequency heating apparatus configured in this way, there is an apparatus described in Patent Document 1, for example.
JP 2007-36110 A

The heat-generating body is made of, for example, a stainless plate, and generates heat by induction heating by the induction coil as described above. On the other hand, the heat-generating body to be heated generates an amount of radiation corresponding to the surface state. It releases heat.
In other words, the radiant heat emitted from the heat generating member depends on the magnitude of the emissivity on the outer surface of the heat generating member, and more radiant heat is released as the emissivity increases.

  For example, when the outer surface of the heat generating body is polished or the like, and no oxide film is formed on the outer surface (emissivity ε = 0.26), little radiant heat is emitted, and the outside of the heat generating body When the outer surface with some oxide film formed on the surface is somewhat rusted (emissivity ε = 0.61), more radiant heat is released than when no oxide film is formed. When the outer surface of the heating element is covered with a thick oxide film as a whole, the outer surface is severely rusted (emissivity ε = 0.85). Heat will be released.

For example, even if an oxide film is not formed on the outer surface at the start of use, the heat generating body gradually forms an oxide film as it is used. The degree of film formation is different, and the degree of oxide film formation differs depending on the location within the same heat generating body.
Therefore, even if the heat generation amount by the induction heating in the plurality of heat generating bodies is made the same, the radiant heat emitted from each heat generating body becomes different as the heat generating bodies are used repeatedly. This is the cause of variations in the temperature of each heat generating body and the temperature depending on the location in the same heat generating body.
As described above, when the temperature varies depending on each heat generating body or the location within the same heat generating body, the heating temperature of the circuit board placed on the heat generating body varies, and the soldering state of the electronic component is made uniform. It becomes difficult.

Maintaining the heating temperature of the circuit board placed on the heat generating body uniformly means that the state of oxide film formation of each heat generating body is detected, and the object of heating by induction heating is detected according to the detected state of oxide film formation. This is possible by controlling the amount of heat generated by the heating element, but there is a problem that the heating process of the device and the circuit board becomes complicated and the cost increases.
Therefore, in the present invention, when a work such as a circuit board is heated by the heat generating body, the temperature of the heat generating body can be easily adjusted without performing a special process such as controlling the heat generation amount of the heat generating body by induction heating. It is possible to provide a high-frequency heating device and a heat generating body thereof that can equalize the temperature.

The high-frequency heating apparatus and its heat generating body that solve the above problems have the following characteristics.
That is, as described in claim 1, a high-frequency heating apparatus configured to generate an alternating magnetic field by energizing an induction coil with an alternating current and to generate a heat generating body arranged in the generated alternating magnetic field, The outer surface of the heat generating member was covered with a film made of a member that does not change the emissivity at the heat generation temperature of the heat generating member.
Thereby, the outer surface of the heat generating member has a uniform emissivity as a whole, and when the heat generating member is heated, the temperature of each place in the outer surface can be easily made uniform.
Further, when the same film is formed on a plurality of heat generating bodies, the emissivity of the film in each heat generating body is the same, so the temperature of each heat generating body when heated can be easily made the same. .
Therefore, when a plurality of heat generating bodies are arranged inside the induction coil and, for example, the semiconductor devices placed on the plurality of heat generating bodies are soldered at the same time, the semiconductor devices are kept at the same temperature. Thus, the soldering quality in each semiconductor device can be kept uniform.

According to a second aspect of the present invention, the heat generating member is configured by a plate-like member, and the film is formed on at least the first plate surface and the first plate surface of the outer surface of the heat generating member. The opposing second plate surface is covered.
In this case, the heat generating body is formed in a plate shape, and the first plate surface and the second plate surface have a remarkably large area compared to the other surfaces. Even if the film is formed only on the surface and the second plate surface, the effect of suppressing the release of radiant heat is almost the same as the case where the film is formed on the entire outer surface, and the temperature of the heat generating body is to be equalized. While making it possible, it is possible to reduce the labor of film formation as compared with the case of forming a film over the entire outer surface.

According to a third aspect of the present invention, the film is composed of a member having an emissivity smaller than that of an oxide film formed on the outer surface of the heat generating body.
As a result, it is possible to suppress the release of radiant heat from the heat generating body, and it is possible to reduce energy loss during heating of the heat generating body and improve energy efficiency.

According to a fourth aspect of the present invention, the film is covered with any one of an electrolytic chromium plating film, an electrolytic nickel plating film, and a chromium nitride film.
As a result, it is possible to obtain an emissivity equivalent to the emissivity of the outer surface of the exothermic body in which no oxide film is formed like the exothermic exothermic body after polishing, which can greatly reduce energy loss. it can.

Further, as described in claim 5, the film is covered with a black heat-resistant coating film.
Thereby, the emissivity of the outer surface of the said to-be-heated body can be made uniform, and workpieces, such as a semiconductor device, can be heated uniformly.

In addition, as described in claim 6, at least one of the outer surfaces of the heat generating body is covered with a film having a different emissivity between the central part and the peripheral part, and the emissivity of the film in the central part Is greater than the emissivity of the film at the peripheral edge.
As a result, compared to the case where the outer surface of the heat generating body is covered with only a single film, the heat generating body during heating can be further soaked, and the workpiece such as a semiconductor device can be heated uniformly. Is possible.

Further, as described in claim 7, the heat generating body of a high-frequency heating device that generates heat by an alternating magnetic field generated from an induction coil through which an alternating current is passed, wherein the outer surface of the heat generating body is attached to the heat generating body. It was coated with a film composed of a member that does not change emissivity at an exothermic temperature.
Thereby, the outer surface of the heat generating member has a uniform emissivity as a whole, and when the heat generating member is heated, the temperature of each place in the outer surface can be easily made uniform.
Further, when the same film is formed on a plurality of heat generating bodies, the emissivity of the film in each heat generating body is the same, so the temperature of each heat generating body when heated can be easily made the same. .
Therefore, when a plurality of heat generating bodies are arranged inside the induction coil and, for example, the semiconductor devices placed on the plurality of heat generating bodies are soldered at the same time, the semiconductor devices are kept at the same temperature. Thus, the soldering quality in each semiconductor device can be kept uniform.

In addition, as described in claim 8, the heat generating member is configured by a plate-like member, and the film is formed on at least the first plate surface and the first plate surface of the outer surface of the heat generating member. The opposing second plate surface is covered.
In this case, the heat generating body is formed in a plate shape, and the first plate surface and the second plate surface have a remarkably large area compared to the other surfaces. Even if the film is formed only on the surface and the second plate surface, the effect of suppressing the release of radiant heat is almost the same as the case where the film is formed on the entire outer surface, and the temperature of the heat generating body is to be equalized. While making it possible, it is possible to reduce the labor of film formation as compared with the case of forming a film over the entire outer surface.

According to a ninth aspect of the present invention, the film is formed of a member having an emissivity smaller than that of an oxide film formed on the outer surface of the heat generating body.
As a result, it is possible to suppress the release of radiant heat from the heat generating body, and it is possible to reduce energy loss during heating of the heat generating body and improve energy efficiency.

According to a tenth aspect of the present invention, the film is covered with any one of an electrolytic chromium plating film, an electrolytic nickel plating film, and a chromium nitride film.
As a result, it is possible to obtain an emissivity equivalent to the emissivity of the outer surface of the exothermic body in which no oxide film is formed like the exothermic exothermic body after polishing, which can greatly reduce energy loss. it can.

In addition, as described in claim 11, the film is covered with a black heat-resistant coating film.
Thereby, the emissivity of the outer surface of the said to-be-heated body can be made uniform, and workpieces, such as a semiconductor device, can be heated uniformly.

In addition, as described in claim 12, at least one of the outer surfaces of the heat generating body is covered with a film having a different emissivity between a central part and a peripheral part, and the emissivity of the film in the central part Is greater than the emissivity of the film at the peripheral edge.
As a result, compared to the case where the outer surface of the heat generating body is covered with only a single film, the heat generating body during heating can be further soaked, and the workpiece such as a semiconductor device can be heated uniformly. Is possible.

According to the present invention, the outer surface of the heat generating body has a uniform emissivity as a whole, and the temperature of each place in the outer surface can be made uniform when the heat generating body is heated.
When the same film is formed on a plurality of heat generating bodies, the temperatures of the respective heat generating bodies when heated can be made the same.

  Next, modes for carrying out the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 1, 2, and 3, the high-frequency heating device 10 according to the embodiment of the present invention is placed on the circuit board 2 while the electronic component 3 is positioned by the positioning jig 5. A conveyor 12 that conveys the semiconductor device 1 in a state where a pellet-shaped solder 4 is interposed between the circuit board 2 and the electronic component 3, an induction coil 11 that is disposed so as to surround the conveyor 12, and is a heating target. A temperature measuring device 14 that measures the temperature of the semiconductor device 1 that is a workpiece, and a controller 13 that controls the induction coil 11 and the temperature measuring device 14 are provided.
The conveyor 12, the induction coil 11, the temperature measuring instrument 14, and the like are accommodated in a vacuum chamber of a reflow furnace.

The induction coil 11 is arranged in a range wider than the length of the semiconductor device 1 in the transport direction of the semiconductor device 1 by the conveyor 12.
In addition, the inner space surrounded by the induction coil 11 is formed in a size sufficient for the semiconductor device 1 placed on the conveyor 12 to be conveyed.

The semiconductor device 1 is disposed on a heat generating body (susceptor) 17, and the lower surface of the circuit board 2 of the semiconductor device 1 and the upper surface of the heat generating body 17 are in contact with each other.
Further, the heat generating body 17 on which the semiconductor device 1 is placed is disposed on the conveyor 12 via the carrier 16.
As described above, the semiconductor device 1 is placed on the conveyor 12 via the heat generating body 17 and the carrier 16, and the plurality of heat generating bodies 17 on which the semiconductor device 1 is placed are conveyed on the conveyor 12. ing.

In the high-frequency heating device 10 configured as described above, when the semiconductor device 1 is transported into the space surrounded by the induction coil 11, an alternating current is passed through the induction coil 11 by the controller 13.
When an alternating current is passed through the induction coil 11, an alternating magnetic field is generated in the space surrounded by the induction coil 11, and the heat-generating body arranged in the space surrounded by the induction coil 11 by the generated alternating magnetic field. When an alternating current is generated in 17 and the alternating current flows through the heat generating body 17, the heat generating body 17 generates heat.
That is, an induction heating phenomenon occurs in the heat generating body 17 due to an alternating magnetic field generated by applying an alternating current to the induction coil 11, and the heat generating body 17 is heated.

In general, the induction heating phenomenon means that an alternating magnetic field is generated by an induction coil energized with alternating current, an alternating current is generated in a magnetic body or conductor existing in the alternating magnetic field, and the magnetic body generates heat by the alternating current. A phenomenon that causes
Further, the heat-generating body 17 is preferably a magnetic body, and is a member that generates heat when a current flows when exposed to an alternating magnetic field.

As described above, when the heat generating body 17 is heated by the induction heating phenomenon caused by the alternating current from the induction coil 11, the heat from the heat generating body 17 is soldered through the circuit board 2 placed on the heat generating body 17. 4, the solder 4 is heated and melted.
The high-frequency heating apparatus 10 is configured to measure the heating temperature of any one of the solder 4, the circuit board 2, and the heat generating body 17 with the temperature measuring instrument 14, and induction based on the measured temperature. The controller 13 controls the amount of current flowing through the coil 11 so that the temperature of the solder 4, the circuit board 2, or the heat generating body 17 is constant.

  As described above, the high-frequency heating device 10 used when soldering the circuit board 2 and the electronic component 3 applies the AC magnetic field generated from the induction coil 11 to the heat generating body 17 and heats it. The solder 4 is heated and melted by heat transfer from the heating element 17.

Next, the heating element 17 heated by the induction heating phenomenon will be described in detail.
In the case of this example, the heat generating body 17 is made of a stainless material formed in a plate shape.

Here, the heat generating body 17 generates heat by being induction-heated by the induction coil 11. On the other hand, as shown in FIG. 4, the heat generating body 17 that has generated heat emits radiant heat from the surface.
The radiant heat (radiant energy) emitted from the heat generating body 17 is represented by the following equation (1).
E = 5.67ε × (T / 100) ⁴ (1)
In the above formula (1), E represents the radiant energy emitted from the heat generating body 17, ε represents the emissivity of the outer surface of the heat generating body 17, and T represents the temperature of the heat generating body 17. .

That is, the radiant heat (radiant energy) emitted from the heat generating body 17 depends on the magnitude of the emissivity ε on the outer surface of the heat generating body 17, and the radiant heat emitted if the emissivity ε is small. If the emissivity ε is large, a large amount of radiant heat is released.
Therefore, even when the heat generating body 17 is heated to a predetermined temperature, if the emissivity ε of the outer surface thereof is different, the actual temperature of the heat generating body 17 varies depending on the difference in the emissivity ε.

For example, FIG. 5 shows a state where the outer surface is polished and the metal surface is exposed (ε = 0.26), and the heat generating body 17 is oxidized and the outer surface is oxidized and covered with an oxide film (ε = 0.85) and the heat generating body 17 in a black body coating state (ε = 0.94) in which a black coating is formed on the outer surface by applying a black body paint to each of the predetermined temperatures. The figure shows the temperature change when the sample is left after being heated to T.
According to FIG. 5, in the heat generating body 17 covered with an oxide film having a high emissivity ε and the heat generating body 17 in a black coating state, the amount of radiant heat is large, so the degree of temperature decrease is severe and the temperature decreases in a short time. The exothermic body 17 having a metal surface with a low emissivity ε is exposed to a low temperature and has a moderate temperature decrease and maintains a high temperature for a long time.

  Thus, since the radiant heat radiated differs depending on the state of the outer surface of the heat generating body 17, that is, the emissivity ε of the outer surface, even if the same amount of current flows to the heat generating body 17 due to the induction heating phenomenon, As shown in FIG. 4, the heat generating body 17 is polished and the outer surface is not covered with an oxide film and the metal surface is exposed (the heat generating body 17 in this state has a small amount of radiant heat). As shown in FIG. 6, the actual heating temperature is different from that of the heat generating body 17 whose outer surface is covered with the oxide film 18 (the heat generating body 17 in this state has a large amount of radiant heat).

In addition, even when the heat generating body 17 is in a state in which the oxide film 18 is not formed on the outer surface at the start of use, for example, the heat generating body 17 is gradually oxidized on the outer surface as it is repeatedly used and heated. A film is formed.
In this case, a plurality of heat generating bodies 17 are transported on the conveyor 12 of the high-frequency heating device 10, but the degree of oxide film formation differs for each heat generating body 17, and even within the same heat generating body 17 depending on the location. Is different.
Therefore, the emissivity ε varies depending on each heat-generating body 17 and the place in the same heat-receiving body 17, and the temperature of each heat-receiving body 17 and the temperature depending on the place in the same heat-receiving body 17 may vary. Become.

  Therefore, in the high-frequency heating device 10, the following treatment is performed on the outer surface of the heat generating body 17, so that even when the heat generating body 17 is repeatedly used, the heat generating body 17 and the same heat generating body are used. The state in which the emissivity ε is the same at each location in 17 can be maintained.

That is, as shown in FIG. 7, the emissivity ε changes even if the outer surface of the heat generating body 17 is heated to a temperature range where the heat generating body 17 generates heat by induction heating by the induction coil 11. It is covered with a coating film 19 made of a material that does not cause the problem.
In the case of this example, the coating film 19 is formed on the upper surface 17a which becomes the first plate surface of the heat generating body 17 and the lower surface 17b which becomes the second plate surface facing the upper surface 17a.

  In this description, when the heat generating body 17 is heated to a temperature range where heat is generated by induction heating by the induction coil 11, “the emissivity ε does not change” means that the emissivity ε does not change at all. In addition to the state, the emissivity ε changes slightly, but the change is such that the temperature change of the heat generating body 17 due to the increase or decrease in the amount of radiant heat does not have a practical effect on the heating temperature of the semiconductor device 1. Including cases.

Specifically, the coating film 19 includes a chromium film (electrolytic chromium plating film) formed by electrolytic plating, a nickel film (electrolytic nickel plating film) formed by electrolytic plating, and PVD (Physical Vapor). It is possible to apply a chromium nitride film formed by Deposition.

An electroless nickel plating film that is the same nickel plating film as the electrolytic chromium plating film is not suitable as a film to be applied to the coating film 19.
This is because the electroless nickel plating film is an alloy of nickel (Ni) and phosphorus (P), and when the electroless nickel plating film is heated, the color changes due to the reaction of phosphorus and the emissivity ε changes. .
On the other hand, the electrolytic chrome plating film does not contain phosphorus (P), does not change color even when heated, and the emissivity ε is kept constant. Is suitable.

The electrolytic chromium plating film, the electrolytic nickel plating film, and the chromium nitride film used as the coating film 19 have an emissivity ε that is smaller than the emissivity ε of the oxide film 18 formed on the heat generating body 17. Yes.
Specifically, the emissivity ε of each of these films is equivalent to the emissivity ε of the outer surface of the heat generating body 17 in a state where the oxide film 18 is not formed, and the radiant heat from the heat generating body 17 is reduced. It is possible to keep the emission small.

In this way, by making the emissivity ε of the coating film 19 smaller than the emissivity ε of the oxide film 18 formed on the heat generating body 17, the emission of radiant heat can be suppressed to be small, and the heat generating body 17 can be heated. Energy loss at the time can be reduced.
In particular, by using an electrolytic chromium plating film, an electrolytic nickel plating film, and a chromium nitride film as the coating film 19, the heat generating body 17 in a state where the oxide film 18 is not formed like the heat generating body 17 after polishing. An emissivity ε equivalent to the emissivity ε of the outer surface can be obtained, and energy loss can be greatly reduced.

The coating film 19 is formed on the outer surface of the heat generating body 17 as follows.
For example, as shown in FIG. 8 (a), an oxide film 18 is formed on the outer surface of the heat generating body 17 that is normally left in the atmosphere. The outer surface of the heat generating body 17 on which 18 is formed is polished to expose the metal surface of the heat generating body 17.
Next, the coating film 19 is formed on the outer surface of the heat generating body 17 where the metal surface is exposed by electrolytic plating, PVD, or the like. In this case, the coating film 19 is preferably formed to have a uniform thickness.

By forming the coating film 19 on the outer surface of the heat generating body 17 in this way, the outer surface of the heat generating body 17 has a uniform emissivity ε as a whole. When heated, the temperature at each location in the outer surface can be made uniform.
Further, when the same coating film 19 is formed on the plurality of heat generating bodies 17, the emissivity ε of the coating film 19 in each heat generating body 17 is the same. The temperature can be the same.

  Thus, when the plurality of heat generating bodies 17 are arranged inside the induction coil 11 and the semiconductor device 1 placed on the plurality of heat generating bodies 17 is soldered at the same time, each semiconductor device 1 can be heated to the same temperature, and the soldering quality in each semiconductor device 1 can be kept uniform.

  Further, since the coating film 19 is made of a material that hardly changes the emissivity ε in the temperature range where the heat generating body 17 is heated (that is, the electrolytic chromium plating film, the electrolytic nickel plating film). And the chromium nitride film are materials that are difficult to oxidize), so that the emissivity ε of the coating film 19 does not change even when the heat generating body 17 is repeatedly used in the high-frequency heating device 10. It is possible to prevent the temperature of the heat generating body 17 from changing over time.

Further, by forming the coating film 19 on the outer surface of the heat generating body 17, the outer surface can be disconnected from the atmosphere, so that the outer surface of the heat generating body 17 is oxidized and rusted. It is also possible to obtain an anti-rust effect.
In the case of this example, as shown in FIG. 7, the coating film 19 is formed only on the upper surface 17a and the lower surface 17b of the outer surface of the heat generating body 17, but the heat generating body 17 is plate-shaped. Therefore, it is possible to form the coating film 19 only on the upper surface 17a and the lower surface 17b having a remarkably large area compared to the other surfaces of the outer surface of the heat generating body 17, It is possible to obtain substantially the same radiation heat emission suppressing effect as that in the case where the coating film 19 is formed on the entire outer surface and to equalize the temperature of the heat generating body 17.

As described above, the coating film 19 formed on the upper surface 17a and the lower surface 17b of the heat generating body 17 may be a film having the same components on the upper surface 17a and the lower surface 17b (for example, both are electrolytic nickel plating films). However, films of different components (for example, one surface is an electrolytic nickel plating film and the other film is an electrolytic chromium plating film) may be used.
It is also possible to interpose a copper plating film or the like between the outer surface of the heat generating body 17 and the coating film 19.

Moreover, as a process for making the emissivity ε of the outer surface of the heat generating body 17 uniform, the following process can be performed.
That is, as shown in FIG. 9, the emissivity ε of the outer surface of the heat generating body 17 is made uniform by coating the outer surface of the heat generating body 17 with black body paint to form a black coating film 20. Thus, as in the case where the coating film 19 is formed on the outer surface of the heat generating body 17, the semiconductor device 1 can be heated uniformly.

The black body paint for forming the black coating film 20 is prepared by mixing a pigment such as carbon black, a highly heat-resistant synthetic resin such as an epoxy resin or a polyimide resin, and a dispersion medium such as dimethyl ether. .
By performing black body coating in which the black body paint thus adjusted is applied to the outer surface of the heat generating body 17, a high heat resistance in which almost no change in emissivity ε is observed in the heating temperature range of the heat generating body 17. The black coating film 20 can be formed.

The black body paint can be formed by baking to form a black coating film 20 having particularly high heat resistance and almost no change in emissivity ε.
The black coating film 20 is the same as the coating film 19 such as an electrolytic plating film from the viewpoint of uniformizing the emissivity ε of the outer surface of the heat generating body 17, but the emissivity ε is 0. Since it is about 94, it is the same as the oxide film 18 from the viewpoint of energy efficiency.

Further, as a process for making the emissivity ε of the outer surface of the heat generating body 17 uniform, the following process can be performed.
That is, as shown in FIG. 10, the black coating film 20 is formed at the center of one or both of the upper surface 17 a and the lower surface 17 b of the heat generating body 17 (the lower surface 17 b is shown in FIG. 10). The coating film 19 is formed on portions other than the black coating film 20.

In the heat generating body 17 arranged in the induction coil 11, the central part is exposed to more alternating magnetic field than the end part during heating, and therefore tends to be high temperature.
Therefore, as described above, the black coating film 20 having a large emissivity ε and a large amount of radiant heat emission is formed at the central portion of the upper surface 17a and the lower surface 17b, and the emissivity ε is small and the radiant heat is reduced at the peripheral portion. Forming the coating film 19 that emits less and increasing the heat radiation amount at the central part where the black coating film 20 is formed when heating the heat-generating body 17, and the heat radiation amount at the peripheral part where the coating film 19 is formed. By reducing the temperature, the temperature difference between the central portion and the peripheral portion of the heat generating body 17 is eliminated, and the temperature of the heat generating body 17 is made uniform as a whole.

  In this way, by forming a film having a different emissivity ε in one surface on the outer surface of the heat generating body 17, compared with the case where only the coating film 19 is formed on the outer surface of the heat generating body 17. Thus, the heat generating body 17 during heating can be further soaked, and the semiconductor device 1 can be heated uniformly.

It is a perspective view which shows a high frequency heating apparatus. It is a top view which shows a high frequency heating apparatus. It is side surface sectional drawing which shows the inside of the induction coil of a high frequency heating apparatus. It is side surface sectional drawing which shows the to-be-heated body in the state in which the oxide film is not formed in the outer surface. It is a figure which shows the temperature change difference of a to-be-heated body by the state of an outer surface. It is side surface sectional drawing which shows the to-be-heated body in the state by which the oxide film was formed in the outer surface. It is side surface sectional drawing which shows the to-be-heated body in the state by which the coating film was formed in the outer surface. It is side surface sectional drawing which shows the process in which a coating film is formed in the outer surface of a to-be-heated body. It is side surface sectional drawing which shows the to-be-heated body in the state in which the black coating film was formed in the outer surface. It is a bottom view which shows the to-be-heated body in the state which formed the black coating film in the center part of the lower surface, and formed the coating film in the peripheral part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor device 2 Circuit board 3 Electronic component 4 Solder 5 Positioning jig 10 High-frequency heating device 11 Induction coil 12 Conveyor 17 Heating object 18 Oxide film 19 Coating film 20 Black coating film

Claims (12)

A high-frequency heating apparatus configured to generate an alternating magnetic field by energizing an induction coil with an alternating current, and to generate heat to the heat generating body arranged in the generated alternating magnetic field,
The outer surface of the exothermic body is covered with a film made of a material that does not change emissivity even when heated to the exothermic temperature of the exothermic body,
A high-frequency heating device characterized by that. The heat generating body is composed of a plate-shaped member,
The film covers at least a first plate surface and a second plate surface facing the first plate surface, of the outer surface of the heat generating body,
The high-frequency heating device according to claim 1. The film is composed of a member having an emissivity smaller than the emissivity of an oxide film formed on the outer surface of the heat generating body.
The high-frequency heating device according to claim 1 or 2, wherein The film is covered with any one of an electrolytic chromium plating film, an electrolytic nickel plating film, and a chromium nitride film.
The high frequency heating apparatus according to any one of claims 1 to 3, wherein the high frequency heating apparatus is characterized. The film is covered with a black heat-resistant coating film,
The high-frequency heating device according to claim 1 or 2, wherein Among the outer surfaces of the heat-generating body, at least one outer surface is covered with a film having different emissivity at the central portion and the peripheral portion,
The emissivity of the central film is greater than the emissivity of the peripheral film,
The high frequency heating apparatus according to any one of claims 1 to 3, wherein the high frequency heating apparatus is characterized. A heating object of a high-frequency heating device that generates heat by an alternating magnetic field generated from an induction coil through which alternating current is applied,
The outer surface of the exothermic body was covered with a film composed of a member that does not change emissivity at the exothermic temperature of the exothermic body.
An object to be heated of a high-frequency heating device. The heat generating body is composed of a plate-shaped member,
The film covers at least a first plate surface and a second plate surface facing the first plate surface, of the outer surface of the heat generating body,
The heat generating body of the high-frequency heating device according to claim 7. The film is composed of a member having an emissivity smaller than the emissivity of an oxide film formed on the outer surface of the heat generating body.
The heat generating body of the high-frequency heating device according to claim 7 or 8, The film is covered with any one of an electrolytic chromium plating film, an electrolytic nickel plating film, and a chromium nitride film.
The heat-generating body of the high-frequency heating device according to any one of claims 7 to 9, wherein The film is covered with a black heat-resistant coating film,
The heat generating body of the high-frequency heating device according to claim 7 or 8, Among the outer surfaces of the heat-generating body, at least one outer surface is covered with a film having different emissivity at the central portion and the peripheral portion,
The emissivity of the central film is greater than the emissivity of the peripheral film,
The heat-generating body of the high-frequency heating device according to any one of claims 7 to 9, wherein

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