JP2016103408A - Infrared ray processing device and infrared heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a temperature difference between a heat generating body and a filter part during use.SOLUTION: An infrared ray processing device 10 comprises: a heat generating part 20 having a heat generating body that radiates infrared ray by the application of heat thereto; and a filter part 50 having a reflecting characteristic that reflects an infrared ray in a predetermined reflecting wavelength region and also having a first transmission layer that transmits at least some of an infrared ray from the heat generating body. The heat generating body is able to absorb an infrared ray of a reflecting wavelength region, and includes: an infrared ray heater 10 in which a first space 47 between the heat generating body and the first transmission layer is open in an external space; and a furnace body 80 defining a processing space 81 that does not communicate with the first space 47 directly and used as a space for performing an infrared ray processing by means of infrared ray radiated from the heat generating body and transmitted through the filter part 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an infrared processing apparatus and an infrared heater.

  2. Description of the Related Art Conventionally, various structures have been developed as infrared heaters that emit infrared rays (wavelength range: 0.7 to 1000 μm) and devices equipped with the infrared heaters. For example, Patent Literature 1 describes an apparatus that includes an infrared heater that irradiates a workpiece with infrared rays, and an infrared selective transmission filter that is disposed between the workpiece and the infrared heater. In this apparatus, the infrared selective transmission filter selectively transmits a wavelength portion that is favorably absorbed by the sealant attached to the workpiece and reflects other wavelength portions. Thereby, the infrared selective transmission filter itself is not heated, and the work is not deteriorated due to an increase in the atmospheric temperature due to the heating of itself.

Japanese Patent Laid-Open No. 9-136055

  However, in the apparatus described in Patent Document 1, infrared energy reflected by the filter is unnecessary energy that is not used for heating the sealing agent. And the furnace wall and the inside of a furnace became high temperature by this reflected infrared energy, and the temperature of the filter might rise by this. When the temperature of the filter rises, for example, the output of the infrared heater or the continuous use may be limited from the viewpoint of heat resistance of the filter.

  The present invention has been made to solve such a problem, and has as its main object to increase the temperature difference between the heating element and the filter section during use.

  The present invention employs the following means in order to achieve the main object described above.

The infrared processing apparatus of the present invention is
An infrared processing apparatus that performs infrared processing by emitting infrared rays to an object,
A heating element that emits infrared rays when heated, and a filter unit that has a reflection characteristic that reflects infrared rays in a predetermined reflection wavelength region and includes a first transmission layer that transmits at least part of infrared rays from the heating element; An infrared heater in which the heating element can absorb infrared rays in the reflection wavelength region, and a first space between the heating element and the first transmission layer is open to an external space;
A furnace body that is not in direct communication with the first space and forms a treatment space that is a space for performing the infrared treatment by infrared rays after being emitted from the heating element and transmitted through the filter unit;
It is equipped with.

  In this infrared processing apparatus, when the heating element is heated, infrared rays are emitted, and the infrared rays pass through the filter portion including the first transmission layer and are emitted to the processing space in the furnace. At this time, the first transmission layer has a reflection characteristic of reflecting infrared rays in a predetermined reflection wavelength region. The heating element can absorb infrared rays in the reflection wavelength region. For this reason, the first transmission layer reflects infrared rays in the reflection wavelength region, so that the temperature is less likely to rise compared to the case of absorbing the first transmission layer. On the other hand, since the heating element can absorb a part of infrared rays emitted from itself and can be used for heating itself, the temperature easily rises. As a result, the temperature difference between the heating element and the filter unit (especially the first transmission layer) during use can be increased. Note that the temperature difference between the heating element and the filter portion becomes large, for example, the heating element can be heated to a high temperature while keeping the temperature of the first transmission layer below the heat-resistant temperature, and is emitted to the object in the processing space. Infrared energy can be increased. Moreover, even if the temperature of the heating element is the same, the infrared processing apparatus of the present invention can keep the filter part at a lower temperature, and can suppress the temperature rise of the furnace body and the processing space due to the temperature rise of the filter part. In the infrared processing apparatus of the present invention, the first transmission layer may have an infrared reflectance of 70% or more in the reflection wavelength region. Here, the external space may be a vacuum or an atmosphere other than a vacuum.

In the infrared processing apparatus of the present invention, the distance between the heating element and the first transmission layer is a distance D [cm], and the heating element is projected onto the first transmission layer in a direction perpendicular to the first transmission layer. The area of the minimum rectangular or circular area surrounding the entire projection area is defined as a heating element area S [cm ² ] (where 0 cm ² <heating element area S ≦ 400 cm ² ), and the representative dimension L When [cm] = 2 × √ (heating element area S / π), 0.08 ≦ distance D / representative dimension L ≦ 0.23 may be satisfied. Here, as the distance D / representative dimension L is smaller, the heat transfer from the heating element to the first transmission layer becomes unavoidable depending on the heat conduction through the atmosphere in the first space. As a result, the heat retention in the first space is increased, and the temperature of the first transmission layer is likely to rise. Here, by setting the distance D / representative dimension L to be 0.08 or more, the conduction heat flux is prevented from being excessively increased, and the amount of heat transfer between the heating element and the filter unit during use is reduced. The temperature rise of (especially 1st permeation | transmission layer) can fully be suppressed. As the distance D / representative dimension L increases, the heat transfer in the first space now depends on convection, and if the distance D / representative dimension L becomes excessively large, the convection loss in the first space. Increases, and the temperature of the heating element tends to decrease. In this case, by setting the distance D / representative dimension L to be 0.23 or less, it is possible to prevent an increase in the convective heat transfer coefficient and sufficiently suppress the temperature decrease of the heating element due to the convection loss. As described above, by setting 0.08 ≦ distance D / representative dimension L ≦ 0.23, the temperature of the heating element and the filter portion (particularly the first transmission layer) is suppressed while suppressing the temperature drop of the heating element during use. The difference can be made larger. As a result, more infrared energy from the heating element goes to the transmitted portion of the filter section and is introduced into the processing space, so that infrared processing (for example, heating) can be performed efficiently. Here, “the area of the smallest rectangular or circular area surrounding the entire projection area” means that the smallest rectangular area and the smallest circular area surrounding the entire projection area are drawn with the smaller area. It means the area of the region. Further, the “rectangle” is not limited to a square or a rectangle, but includes a parallelogram and other rectangles. “Circle” includes not only a perfect circle but also an ellipse. Further, since the above-described effect when 0.08 ≦ distance D / representative dimension L ≦ 0.23 is satisfied can be obtained more reliably, the area of the projection region / the heating element area S ≧ 0.5. preferable. In the infrared processing apparatus of the present invention in which 0.08 ≦ distance D / representative dimension L ≦ 0.23, the “first space is open to the external space” state refers to the above-described effect (first It means a state in which the first space and the external space communicate freely with the entry and exit of the atmosphere to the extent that the effect of suppressing the heat retention in one space and suppressing the temperature increase of the first transmission layer is obtained. . The external space may be an atmosphere other than vacuum. The external space may be an atmospheric atmosphere. That is, the first space may be open to the atmosphere.

  In the infrared processing apparatus of the present invention, the heating element and the first space may be located outside the furnace body. In this case, since the first space is located outside the furnace body, the temperature increase of the first permeable layer is further suppressed, so that the temperature difference between the heating element and the filter unit during use can be further increased. .

  The infrared processing apparatus of the present invention may be provided with a reflecting member that is disposed on the side opposite to the first transmission layer as viewed from the heating element and reflects at least infrared rays in the reflection wavelength region. If it carries out like this, a heat generating body can be heated with the infrared rays which the reflecting member reflected because a reflecting member reflects the infrared rays which look at the heat transmitting element on the opposite side to the 1st transmitting layer to the 1st transmitting layer side. Therefore, the temperature difference between the heating element and the filter unit (especially the first transmission layer) in use can be further increased. The reflecting member may also reflect infrared light outside the reflection wavelength region.

  In the infrared processing apparatus according to the aspect of the invention, the filter unit may be disposed at a distance from the first transmission layer and the second space, and may include at least a part of infrared rays transmitted through the first transmission layer among infrared rays from the heating element. It has the 2nd permeation | transmission layer which permeate | transmits, and the said process space which the said furnace body forms does not need to connect with the said 2nd space directly. If it carries out like this, the temperature rise of the 2nd permeation | transmission layer by the side of process space among filter parts can be suppressed. Thereby, the temperature rise of a furnace body or process space can be suppressed. The second space may be an atmosphere other than a vacuum. The second transmission layer may have a reflection characteristic of reflecting infrared rays in the reflection wavelength region.

  In this case, the infrared processing apparatus of the present invention may include a cooling unit that circulates the refrigerant in the second space to cool the filter unit. If it carries out like this, the temperature rise of a filter part can be suppressed with a refrigerant | coolant and the temperature difference of the heat generating body and filter part at the time of use can be enlarged more.

  In the infrared processing apparatus of the present invention, the heating element may be a planar heating element having a plane that can emit infrared rays toward the first transmission layer and can absorb infrared rays in the reflection wavelength region. By so doing, for example, compared with a case where the heating element is a linear heater, it becomes easier to absorb infrared rays reflected by the first transmission layer, and the temperature of the heating element is likely to rise. Therefore, the temperature difference between the heating element and the filter unit during use can be further increased.

The infrared heater of the present invention is
A heating element that radiates infrared when heated,
A filter having a reflection characteristic that reflects infrared rays in a predetermined reflection wavelength region and is separated from the heating element by a first space and that transmits at least part of infrared rays from the heating element. And
With
The heating element can absorb infrared rays in the reflection wavelength region;
The first space is open to an external space;
The distance between the heating element and the first transmission layer is a distance D [cm], and a region in which the heating element is projected onto the first transmission layer in a direction perpendicular to the first transmission layer is defined as a projection area. The area of the smallest rectangular or circular area surrounding the entire projection area is defined as a heating element area S [cm ² ] (where 0 cm ² <heating element area S ≦ 400 cm ² ) and representative dimension L [cm] = 2 × √ ( When the heating element area S / π),
0.08 ≦ distance D / representative dimension L ≦ 0.23,
Is.

  In the infrared heater, similarly to the above-described infrared processing apparatus of the present invention, the first transmission layer reflects the infrared rays in the reflection wavelength region, so that the temperature is less likely to rise as compared with the case of absorbing. On the other hand, since the heating element can absorb a part of infrared rays emitted from itself and can be used for heating itself, the temperature easily rises. Moreover, since the 1st space between a heat generating body and the 1st permeation | transmission layer is open | released by external space, the heat retention in 1st space is suppressed and the temperature rise of a 1st permeation | transmission layer is suppressed. Further, 0.08 ≦ distance D / representative dimension L ≦ 0.23. Therefore, when the distance D / representative dimension L is 0.08 or more, the temperature rise of the filter portion (particularly the first transmission layer) can be sufficiently suppressed. Moreover, since the distance D / representative dimension L is 0.23 or less, the temperature reduction of the heating element due to convection loss can be sufficiently suppressed. From the above, it is possible to increase the temperature difference between the heating element and the filter part (particularly the first transmission layer) while suppressing the temperature drop of the heating element during use. In addition, in the infrared heater of this invention, you may employ | adopt the various aspects of the infrared heater with which the infrared processing apparatus of this invention mentioned above is equipped.

1 is a longitudinal sectional view of an infrared processing apparatus 100. FIG. FIG. 3 is an enlarged sectional view of the infrared heater 10. The bottom view of the heat generating part 20. Explanatory drawing of the relationship between a projection area | region and the heat generating body area S. FIG. The expanded sectional view of the infrared heater 10a of a modification. The graph which shows the relationship between the distance D / representative dimension L in Examples 1-10, the heat generating body 40, the 1st transmission layer 51, the 2nd transmission layer 52, and the temperature of a target object.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of an infrared processing apparatus 100 including a plurality of infrared heaters 10. FIG. 2 is an enlarged cross-sectional view of the infrared heater 10. FIG. 3 is a bottom view of the heat generating portion 20. In the present embodiment, the vertical direction, the horizontal direction, and the front-back direction are as shown in FIGS.

  The infrared processing apparatus 100 is configured as a drying furnace that performs infrared processing (here, drying of the coating film 92) by radiating infrared rays to an object (coating film 92) formed on the semiconductor element 90. The furnace body 80 which forms 81, the belt conveyor 85, and the some infrared heater 10 are provided. The furnace body 80 is a heat insulating structure formed in a substantially rectangular parallelepiped, and forms a processing space 81 therein. A plurality of infrared heaters 10 (six in FIG. 1) are attached to the ceiling portion of the furnace body 80, and infrared rays from the infrared heaters 10 are radiated into the processing space 81. The belt conveyor 85 includes a belt that penetrates the left and right ends of the furnace body 80 and penetrates the processing space 81, and conveys the semiconductor element 90 from left to right. The coating film 92 formed on the semiconductor element 90 is a coating film containing, for example, silicone and toluene, and serves as a protective film for the semiconductor element 90 after drying.

  As shown in FIGS. 1 and 2, the infrared heater 10 includes a heat generating part 20 and a filter part 50 attached below the heat generating part 20. The heating unit 20 includes a case 22 that covers the upper side of the infrared heater 10, a heating element 40 that emits infrared rays when heated, a support plate 30 that supports the heating element 40 in the case 22, and a heating element 40 in the vertical direction. And a reflection member 23 disposed between the support plate 30 and the case 22.

  The case 22 is a member that houses the heating element 40 and the like, and is a substantially rectangular parallelepiped box-shaped member that opens downward. The case 22 includes a fixture (not shown) that fixes the reflecting member 23 and the support plate 30 disposed therein. In addition, the case 22 includes a fixture (not shown) for attaching and fixing the infrared heater 10 to another member (not shown).

  The reflection member 23 is a plate-like member disposed on the side opposite to the first transmission layer 51 (upper side of the heating element 40) when viewed from the heating element 40. The reflection member 23 is configured as a member that reflects infrared rays emitted from the heating element 40, and is formed of metal (for example, SUS or aluminum) in the present embodiment.

  The support plate 30 is a flat plate-like member that supports the heating element 40 when the heating element 40 is wound, and is made of an insulator such as mica or alumina ceramic. As shown in FIG. 3, the support plate 30 has a plurality of front convex portions 31 formed on the front side (six locations in the present embodiment) and a plurality of rear projections formed on the rear side (five locations in the present embodiment). Part 32. The front convex portion 31 and the rear convex portion 32 have a trapezoidal shape in a bottom view, and are arranged on the top portion having a plane parallel to the left and right direction and the left and right sides of the top portion and inclined from the left and right direction (for example, 45 °) slope. The plurality of front protrusions 31 and the plurality of rear protrusions 32 are respectively arranged at a constant pitch in the left-right direction, whereby the front side and the rear side of the support plate 30 are uneven. Further, the front convex portion 31 and the rear convex portion 32 are arranged with a ½ pitch shift in the left-right direction. Note that holes are formed in the support plate 30 (two places in FIG. 3), and infrared rays from the heating element 40 can reach the upper reflecting member 23 through the holes.

  The heating element 40 is a ribbon-like heating element, and is configured as a so-called planar heating element. The heating element 40 is made of a metal such as a Ni—Cr alloy. The heating element 40 can absorb at least part of infrared rays in the reflection wavelength region (described later) on the surface (lower surface) on the first transmission layer 51 side, and the absorptance is preferably 70% or more, and 80% or more. , 90% or more is more preferable. In the present embodiment, the surface of the heating element 40 is coated with a ceramic sprayed film, thereby increasing the emissivity and absorption rate of infrared rays. Examples of the material of the ceramic sprayed film include alumina and chromia. Further, the heating element 40 has infrared rays on the surface opposite to the first transmission layer 51 (upper surface of the heating element 40) than the infrared emissivity on the surface on the first transmission layer 51 side (lower surface of the heating element 40). Preferably, the emissivity is low. In the present embodiment, only the lower surface of the heating element 40 is coated with a ceramic sprayed film, and the emissivity of infrared rays is lower on the upper surface than the lower surface of the heating element 40. The infrared emissivity of the upper surface of the heating element 40 is preferably 30% or less. The shapes of the support plate 30 and the heating element 40 as shown in FIGS. 2 and 3 are known, and are described in, for example, JP-A-2006-261095.

  As shown in FIG. 3, the heating element 40 extends the lower surface side of the support plate 30 a plurality of times in the front-rear direction from the left rear folded end 41 to the right rear folded end 41 (12 in this embodiment). It is wound around the support plate 30 so as to pass. More specifically, the heating element 40 is drawn from the left rear folded end 41 toward the front convex portion 31 on the lower surface side of the support plate 30, and folded along the left slope of the front convex portion 31. And passes through the upper surface side of the front convex portion 31 (see the enlarged portion in the upper right of FIG. 3). Then, the heating element 40 that has passed through the upper surface side of the front convex portion 31 is folded along the right slope of the front convex portion 31 and is routed toward the rear convex portion 32 on the lower surface side of the support plate 30, It is folded along the slope of the rear convex portion 32, passes through the upper surface side of the rear convex portion 32, and is drawn toward the front convex portion 31 on the lower surface side of the support plate 30. In this manner, the heating element 40 is alternately wound around the front convex portion 31 and the rear convex portion 32 while passing through the lower surface side of the support plate 30 in the front-rear direction, and is routed to the right rearward folding end portion 41. ing. Although not shown in detail, the heating element 40 is folded back to the upper surface side of the support plate 30 at the folded end portions 41 and 41, and both ends of the heating element 40 are connected to the case 22. Each is connected to a pair of input terminals (not shown) attached. Electric power can be supplied to the heating element 40 from the outside via the pair of input terminals. The lower surface of the heating element 40 is opposed to the upper surface of the first transmission layer 51, and all the surfaces are disposed so as to be substantially parallel to the horizontal direction (front / rear / left / right direction).

Here, in the heating element 40, the distance between the heating element 40 and the first transmission layer 51 is a distance D [cm] (see FIG. 2), and the heating element 40 is first perpendicular to the first transmission layer 51. The area projected on the transmissive layer 51 is defined as a projection area, and the area of the smallest rectangular or circular area surrounding the entire projection area is defined as a heating element area S [cm ² ] (where 0 cm ² <heating element area S ≦ 400 cm ² ). When the representative dimension L [cm] = 2 × √ (heating element area S / π), it is preferable that 0.08 ≦ distance D / representative dimension L ≦ 0.23, and 0.14 ≦ distance D / Representative dimension L ≦ 0.19 is more preferable. In the present embodiment, the first transmission layer 51 is a flat member, and the heating element 40 and the first transmission layer 51 are disposed in parallel. Therefore, the projection area is the area on the lower surface of the heating element 40 when the heating element 40 is viewed from below (the direction perpendicular to the lower surface of the heating element 40 and the upper surface of the first transmission layer 51) (the heat generation shown in FIG. 3). Area of the shape of the body 40). The smallest rectangular area surrounding the projection area is a rectangular area E shown in FIG. And the product of the length X (= the length from the left end to the right end of the heating element 40) and the length Y in the front-rear direction (= the length in the front-rear direction of the heating element 40) of the rectangular region E Is the heating element area S. As described above, the heating element area S is defined as an area including a portion where the heating element 40 does not exist, such as a left and right gap of the heating element 40 drawn back and forth. The representative dimension L is equal to the diameter of a circle having the same area as the heating element area S. In the present embodiment, the minimum area E surrounding the projection area of the heating element 40 is rectangular, but the heating element area S is better when the projection area is surrounded by a circular area, for example, when the heating element 40 is nearly circular. Is smaller, the area of the smallest circular area surrounding the projection area is defined as the heating element area S. Further, since the effect of satisfying 0.08 ≦ distance D / representative dimension L ≦ 0.23 can be obtained more reliably, it is preferable that the area of the projection region / the heating element area S ≧ 0.5. That is, it is preferable that the area where the heating element 40 (projection area) exists in the area E in FIG. 4 is 50% or more. Further, 1 cm ² <heating element area S ≦ 400 cm ² may be sufficient.

  In addition, the heat generating part 20 and the filter part 50 are connected by a connecting member (not shown), and the mutual positional relationship is fixed. Accordingly, the heating element 40 and the filter unit 50 (first transmission layer 51) are separated from each other via the first space 47. As shown in FIG. 2, the case 22 is vertically separated from the first fixed plate 71, and the first space 47 is formed in an external space (furnace body) via a vertical gap between the case 22 and the first fixed plate 71. 80 space). The heating element 40 and the first transmission layer 51 are exposed in the first space 47. In the present embodiment, the external space is an atmospheric atmosphere.

  The filter unit 50 includes a first transmission layer 51 that transmits at least part of infrared rays from the heating element 40, and a first fixing plate 71 that is a rectangular frame-like member on which the first transmission layer 51 is placed and fixed. It is equipped with. The first fixed plate 71 is attached to the upper part of the furnace body 80.

  The first transmission layer 51 is a plate-like member having a quadrangular shape when viewed from the bottom. The first transmission layer 51 includes a first transmission peak that is a peak of infrared transmittance, a second transmission peak that is longer than the first transmission peak, a wavelength of the first transmission peak, and a second transmission peak. And a reflection characteristic of reflecting infrared rays in a predetermined reflection wavelength region between wavelengths. In the present embodiment, the first transmission layer 51 is configured as an interference filter (optical filter), and as shown in FIG. 2, the upper coat layer 51b covering the upper surface of the substrate 51a and the lower surface covering the lower surface of the substrate 51a. Side coat layer 51c. The upper coat layer 51b is a layer functioning as a band pass layer, and the light of the first and second transmission peaks of the light incident from above the first transmission layer 51 and the infrared rays in the surrounding wavelength region are directed downward. Make it transparent. The upper coat layer 51b reflects upward in the infrared region of the reflection wavelength region. The lower coat layer 51c is a layer that functions as an antireflection film, and suppresses infrared rays (particularly, infrared rays other than the reflection wavelength region) from being reflected upward on the lower surface of the substrate 51a. An example of the material of the substrate 51a is silicon. Examples of the material of the upper coat layer 51b include zinc selenide, germanium, and zinc sulfide. Examples of the material of the lower coat layer 51c include germanium, silicon monoxide, and zinc sulfide. Note that at least one of the upper coat layer 51b and the lower coat layer 51c may have a multilayer structure in which a plurality of types of materials are stacked.

  In the present embodiment, the wavelength of the first transmission peak of the first transmission layer 51 is 2 μm to 3 μm, the wavelength of the second transmission peak is 5 μm to 8.5 μm, and the reflection wavelength region is 3.5 μm to 4.5 μm. It was supposed to be. For example, the upper coat layer 51b is formed by alternately laminating a plurality of zinc sulfides and germanium, and the lower coat layer 51c is formed by alternately laminating a plurality of zinc sulfides and germanium, Such filter characteristics can be obtained by appropriately adjusting the thicknesses of the layer 51bb and the lower coat layer 51c. The infrared transmittance of the first transmission peak and the second transmission peak is preferably 80% or more, and more preferably 90% or more. The infrared reflectance in the reflection wavelength region is preferably 70% or more, more preferably 80% or more and 90% or more. The first transmission layer 51 preferably has an infrared transmittance of 10% or less and more preferably 5% or less in at least a part of the reflection wavelength region. More preferably, the infrared transmittance is 10% or less or 5% or less over the entire reflection wavelength region.

  In addition, although not particularly limited thereto, the first transmission layer 51 may have an infrared transmittance of 40% or more in a wavelength region of a wavelength of 2 μm to 3 μm. The first transmission layer 51 may have an infrared transmittance of 80% or more in a wavelength range of 5 μm to 8.5 μm. The first transmission layer 51 may have an infrared transmittance of 70% or more in a wavelength range of 8.5 μm to 9.5 μm. The first transmission layer 51 may have an infrared transmittance of 60% or more in a wavelength range of 9.5 μm to 13 μm.

  The upper surface (ceiling portion) of the furnace body 80 has a plurality of openings as many as the infrared heaters 10, and the plurality of infrared heaters 10 are attached to the upper part of the furnace body 80 so as to close the openings. ing. Therefore, the lower surface of the first transmission layer 51 is exposed to the processing space 81. The processing space 81 and the first space 47 are partitioned by the first transmission layer 51 and the first fixing plate 71 and are not in direct communication. However, since both the processing space 81 and the first space 47 communicate with the external space of the infrared processing apparatus 100, they communicate with each other via the external space. Further, the infrared heater 10 is arranged so as to protrude above the ceiling of the furnace body 80. Therefore, the heating element 40 and the first space 47 are located outside the furnace body 80.

  A usage example of the infrared processing apparatus 100 configured as described above will be described below. First, a power source (not shown) is connected to the input terminal of the infrared heater 10, and power is supplied to the heating element 40 so that the temperature of the heating element 40 becomes a preset temperature (here, 700 ° C.). The energized heating element 40 emits infrared rays by heating. Further, the semiconductor element 90 having the coating film 92 formed on the upper surface in advance is conveyed by the belt conveyor 85. Thereby, the semiconductor element 90 is carried into the furnace body 80 from the left side of the furnace body 80, passes through the processing space 81, and is carried out from the right side of the furnace body 80. The coating film 92 is dried by the infrared rays from the infrared heater 10 while passing through the processing space 81 (toluene evaporates), and becomes a protective film.

  Here, when the heating element 40 is heated, infrared rays mainly from the lower surface of the heating element 40 are emitted toward the lower filter unit 50 (first transmission layer 51). This infrared ray is incident on the upper surface of the first transmission layer 51 substantially perpendicularly. Of the infrared rays from the heating element 40, the infrared rays within the reflection wavelength region are reflected by the filter unit 50 (mainly the first transmission layer 51), are directed upward, and are absorbed by the heating element 40 (solid line in FIG. 1). See arrow). Thereby, the infrared rays reflected by the filter unit 50 are used for heating the heating element 40. Therefore, less energy (electric power) is input from the outside in order to heat the heating element 40 to 700 ° C. In other words, the temperature of the heating element 40 is likely to rise. On the other hand, since the filter unit 50 (first transmission layer 51) has reflection characteristics, for example, the temperature rise of the filter unit 50 is suppressed as compared with a case where infrared rays in the reflection wavelength region are absorbed. Further, since the first space 47 is open to the external space, the heat retention in the first space 47 is suppressed, and the temperature rise of the first transmission layer 51 is suppressed. As described above, in the infrared heater 10, the temperature of the heating element 40 is likely to rise, and the temperature of the filter unit 50 is difficult to rise. Accordingly, the temperature difference between the heating element 40 and the filter unit 50 (particularly the first transmission layer 51) during use tends to be large.

  In addition, infrared rays in a wavelength region other than the reflected wavelength region among infrared rays from the heating element 40 pass through the filter unit 50 (first transmission layer 51) (see the broken line arrow in FIG. 1) and radiate into the processing space 81. Is done. And the infrared rays radiated | emitted in the process space 81 have two radiation peaks by the filter characteristic mentioned above of the filter part 50 (1st transmission layer 51), and a reflection wavelength area | region (3.5 micrometers-4.5 micrometers). Contains almost no infrared rays. Here, toluene has an infrared absorption peak at, for example, a wavelength of 3.3 μm and a wavelength of 6.7 μm. For this reason, the infrared heater 10 radiates infrared rays having emission peaks having wavelengths near these two absorption peaks into the processing space 81, whereby toluene can be efficiently evaporated from the coating film 92. Then, as the toluene evaporates, a protective film made of silicone can be formed on the surface of the semiconductor element 90. Even if the filter characteristics of the first transmission layer 51 are the same, the wavelength characteristics such as the emission peak of infrared rays radiated into the processing space 81 change due to the temperature of the heating element 40 being different. Therefore, by changing the temperature of the heating element 40, the wavelengths of the two emission peaks of infrared rays radiated into the processing space 81 can be adjusted to some extent. The temperature of the heating element 40 at the time of use can be appropriately determined according to the object so that, for example, the wavelength of the absorption peak of the object and the infrared radiation peak radiated in the processing space 81 are as close as possible.

  According to the infrared processing apparatus 100 of the present embodiment described above, the first transmission layer 51 has a reflection characteristic of reflecting infrared rays in the reflection wavelength region, and the heating element 40 can absorb infrared rays in the reflection wavelength region. is there. Therefore, the first transmission layer 51 reflects infrared rays in the reflection wavelength region, so that the temperature is less likely to rise compared to the case where it absorbs. On the other hand, since the heating element 40 can absorb a part of infrared rays emitted from the heating element 40 and use it for heating itself, the temperature is likely to rise. Accordingly, the temperature difference between the heating element 40 and the filter unit 50 (particularly the first transmission layer 51) during use can be increased. Note that the temperature difference between the heating element 40 and the filter unit 51 is increased, for example, the heating element 40 can be heated to a high temperature while keeping the temperature of the first transmission layer 51 below the heat-resistant temperature, The energy of infrared rays emitted to the object (coating film 92) can be increased. Moreover, even if the temperature of the heating element 40 is the same, the infrared processing apparatus 100 of the present invention can keep the filter unit 50 at a lower temperature, and can suppress the temperature rise of the furnace body 80 and the processing space 81 due to the temperature rise of the filter unit 50. . In the present embodiment, since the external space is an atmospheric atmosphere, the first space 47 is open to the atmosphere. Thus, when the external space is an atmosphere other than vacuum, the first space 47 is opened to the external space, so that heat retention in the first space 47 is suppressed and the temperature of the first transmission layer 51 rises. The effect which suppresses is acquired.

  The infrared heater 10 satisfies 0.08 ≦ distance D / representative dimension L ≦ 0.23. Here, as the distance D / representative dimension L is smaller, the heat transfer from the heating element 40 to the first transmission layer 51 becomes inevitable depending on the heat conduction through the atmosphere (atmosphere) in the first space 51. As a result, the heat retention in the first space 47 is increased, and the temperature of the first transmission layer 51 is likely to rise. Here, by setting the distance D / representative dimension L to be 0.08 or more, it is possible to prevent the conduction heat flux from becoming excessive, and to reduce the amount of heat transfer between the heating element 40 and the filter unit 50 during use. The temperature rise of the filter part 50 (especially the 1st transmission layer 51) can fully be suppressed. As the distance D / representative dimension L increases, the heat transfer in the first space 47 now depends on convection, and when the distance D / representative dimension L becomes excessively large, Convection loss increases and the temperature of the heating element 40 tends to decrease. In this case, by setting the distance D / representative dimension L to 0.23 or less, an increase in the convective heat transfer coefficient can be prevented, and the temperature decrease of the heating element 40 due to the convection loss can be sufficiently suppressed. Thus, by setting 0.08 ≦ distance D / representative dimension L ≦ 0.23, the temperature of the heating element 40 during use is suppressed, and the heating element 40 and the filter unit 50 (particularly the first transmission layer 51). ) And the temperature difference can be further increased. As a result, most of the infrared energy from the heating element 40 travels through the transmitted portion of the filter unit 50 and is introduced into the processing space 81, whereby the infrared treatment of the coating film 92 can be performed efficiently.

  Further, in the infrared processing apparatus 100, the heating element 40 and the first space 47 of the infrared heater 10 are located outside the furnace body 80. Thereby, since the temperature rise of the 1st transmission layer 51 is suppressed more because the 1st space 47 is located outside the furnace body 80, the temperature difference of the heat generating body 40 and the filter part 51 at the time of use is enlarged more. can do.

  Furthermore, the infrared heater 10 is provided on the side opposite to the first transmission layer 51 as viewed from the heating element 40 (above the heating element 40), and includes a reflection member 23 that reflects infrared rays in at least the reflection wavelength region. . Therefore, the heat generating body 40 can be heated by the infrared rays reflected by the reflecting member 23 by reflecting the infrared rays traveling upward from the heat generating body 40 to the first transmission layer 51 side. Therefore, the temperature difference between the heating element 40 and the filter unit 50 (especially the first transmission layer 51) in use can be further increased.

  The heating element 40 is a planar heating element that has a plane that can emit infrared rays toward the first transmission layer 51 and can absorb infrared rays in the reflection wavelength region. Therefore, for example, compared with the case where the heating element 40 is a linear heater, infrared rays reflected by the first transmission layer 51 are easily absorbed, and the temperature of the heating element 40 is likely to rise. Therefore, the temperature difference between the heating element 40 and the filter unit 50 during use can be further increased.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the embodiment described above, the filter unit 50 includes the first transmission layer 51, but the filter unit 50 may further include one or more transmission layers that transmit at least part of the infrared rays from the heating element 40. Good. FIG. 5 is an enlarged cross-sectional view of a modified infrared heater 10a. In addition to the first transmission layer 51 and the first fixing plate 71 described above, the filter unit 50 of the infrared heater 10 a is disposed below the first transmission layer 51 so as to be transmitted through the first transmission layer 51. A second transmission layer 52 that transmits at least part of the second transmission layer 52, a second fixing plate 72 that is a rectangular frame-like member on which the second transmission layer 52 is placed and fixed, and the first transmission layer 51 and the second transmission layer. And a cooling case 60 disposed between the cooling case 60 and the cooling case 60. The second transmission layer 52 is a plate-like member having a quadrangular shape when viewed from the bottom. The upper surface of the second transmissive layer 52 faces the lower surface of the first transmissive layer 51, and the second transmissive layer 52 is disposed substantially parallel to the first transmissive layer 51. The second transmissive layer 52 is spaced apart from the first transmissive layer 51 and the second space 63 in the vertical direction. The lower surface of the second transmission layer 52 is exposed to the processing space 81. The second transmission layer 52 only needs to transmit at least part of the infrared light transmitted through the first transmission layer 51 out of the infrared light from the heating element 40. The second transmissive layer 52 may be made of the same material as the first transmissive layer 51, for example, and may have the same filter characteristics as the first transmissive layer 51. Alternatively, the second transmission layer 52 may not have reflection characteristics and may have a high infrared transmittance as a whole. The second fixed plate 72 is attached to the upper part of the furnace body 80. The cooling case 60 is a substantially rectangular parallelepiped box-shaped member opened up and down. The upper and lower openings of the cooling case 60 are closed by the first transmission layer 51, the first fixing plate 71, the second transmission layer 52, and the second fixing plate 72. For this reason, the second space 63 is formed as a space surrounded by the first and second transmission layers 51 and 52 and the front and rear wall portions of the cooling case 60. Moreover, the cooling case 60 has the refrigerant inlet / outlet 61 on the left and right. The left refrigerant inlet / outlet 61 is connected to a refrigerant supply source 95 (cooling means) disposed in the external space by piping. The refrigerant supply source 95 distributes the refrigerant to the second space 63 through the left refrigerant inlet / outlet 61. The refrigerant that has passed through the second space 63 flows to the outside through the refrigerant inlet / outlet 61 on the right side. The refrigerant supplied from the refrigerant supply source 95 is, for example, a gas such as air or an inert gas, and contacts the first permeable layer 51, the second permeable layer 52, and the cooling case 60 to remove the heat, thereby removing the filter unit 50. Cooling. The second space 63 may be in direct communication with the external space via the right refrigerant inlet / outlet 61, or may not be in direct communication with the external space to which piping or the like is connected. In addition, the first space 47, the second space 63, and the processing space 81 are not in direct communication with each other.

  Even in the infrared processing apparatus including the infrared heater 10a configured as described above, the same effects as those of the infrared processing apparatus 100 of the above-described embodiment can be obtained. Further, since the filter unit 50 includes the second transmission layer 52 and the second space 63 is formed between the first transmission layer 51 and the second transmission layer 52, the heating of the second transmission layer 52 is suppressed. The Thereby, the surface of the infrared heater 10 (the lower surface of the second transmission layer 52) is kept at a relatively low temperature. In addition, by causing the refrigerant to flow through the second space 63, the temperature rise of the filter unit 50 can be suppressed, the surface of the infrared heater 10 can be kept at a lower temperature, or the temperature difference between the heating element 40 and the filter unit 50 can be reduced. Or larger. By keeping the filter unit 50 at a low temperature, temperature rises in the furnace body 80 and the processing space 81 can be suppressed.

  In the infrared heater 10a of FIG. 5, the second space 63 may directly communicate with the external space without supplying the refrigerant from the refrigerant supply source 95. The second space 63 may be open to the external space. Even if the refrigerant is not circulated in the second space 63, the presence of the second space 63 can provide an effect of suppressing the heating of the surface of the infrared heater 10 (the lower surface of the second transmission layer 52 in FIG. 5). Thereby, the temperature of the process space 81, the furnace body 80, etc. can also be kept low. Note that the infrared heater 10 a may not include the cooling case 60 when the refrigerant supply from the refrigerant supply source 95 is not performed. Also in this case, the second space 63 may be formed between the first transmissive layer 51 and the second transmissive layer 52. For example, the first fixed plate 71 and the second fixed plate 72 are separated from each other. A member to be supported may be provided.

  In the above-described embodiment, the first transmission layer 51 has the upper coat layer 51b and the lower coat layer 51c formed on the surface of the substrate 51a. However, the present invention is not limited to this. As long as the first transmissive layer 51 has at least the reflection characteristics described above, at least one of the upper coat layer 51b and the lower coat layer 51c may be omitted.

  In the embodiment described above, the wavelength of the first transmission peak of the filter unit 50 is 2 μm to 3 μm, the wavelength of the second transmission peak is 5 μm to 8.5 μm, and the reflection wavelength region is 3.5 μm to 4.5 μm. It was supposed to be, but it is not limited to this. For example, by appropriately adjusting the film thickness of the substrate 51a, the upper coat layer 51b, and the lower coat layer 51c of the first transmission layer 51, out of the wavelength of the first transmission peak, the wavelength of the second transmission peak, and the reflection wavelength region One or more may be different from the embodiment described above.

  The heating element 40 is not limited to the above-described embodiment. For example, although the lower surface of the heating element 40 is coated with a ceramic sprayed film, the lower surface and the upper surface may be coated or may not be provided with a ceramic sprayed film. Further, although the heating element 40 is a ribbon-like planar heating element wound around the support plate 30, it is not limited thereto. For example, the heating element 40 may be a zigzag planar heating element formed by punching a metal plate. Alternatively, the heating element 40 may be a linear heating element. Further, although the heating element 40 is supported by being wound around the support plate 30, the heating element 40 may be attached to the support plate 30 via a bolt or the like penetrating the heating element 40.

  In the embodiment described above, the first transmission layer 51 is a plate-like member having a quadrangular shape when viewed from the bottom. However, the first transmission layer 51 is not limited thereto, and may be a disk-like member, for example. The same applies to the second transmission layer 52 shown in FIG.

  In the embodiment described above, the infrared heater 10 includes the reflecting member 23. However, instead of not including the reflecting member 23, the case 22 may be made of a material that reflects infrared rays. Further, for example, the lower surface of the reflection member 23 may be covered with a reflection coat that reflects infrared rays. In addition, the infrared heater 10 does not need to include a reflecting member above the heating element 40, such as not including the reflecting member 23 and the case 22 not reflecting infrared rays.

  In the above-described embodiment, in the infrared processing apparatus 100, the infrared heater 10 is disposed above the furnace body 80 so that the first transmission layer 51 is exposed in the processing space 81. However, the present invention is not limited to this. For example, the infrared heater 10 may be disposed inside the furnace body 80. Also in this case, the first space 47 may not be directly communicated with the processing space 81 and may be opened to the external space using, for example, piping or a partition member.

  Hereinafter, an example in which an infrared heater and an infrared processing apparatus including the infrared heater are specifically manufactured will be described as examples. In addition, this invention is not limited to a following example.

[Examples 1 to 10]
In Examples 1-10, the infrared processing apparatus provided with the infrared heater was created, changing distance D / representative dimension L variously as shown in Table 1. The infrared heater has the same configuration as that of the infrared heater 10a except that the cooling case 60 is not provided and the second space 63 is open to the external space. Both the first transmission layer 51 and the second transmission layer 52 have the same material and filter characteristics as the first transmission layer 51 of the above-described embodiment. In addition, the infrared processing apparatus is in a state where only one infrared heater is attached to the furnace body 80. The heating element 40 has the shape shown in FIGS. 3 and 4, and the representative dimension L is 135.4 mm. The heating element 40 was made of a Ni—Cr alloy, and the surface on the first transmission layer 51 side was coated with an alumina ceramic sprayed film. The external space was an atmospheric atmosphere.

[Evaluation test]
In the infrared processing apparatuses of Examples 1 to 10, an object was placed at a position directly below the infrared heater in the processing space 81. And after waiting for temperature to stabilize in the state which supplied about 300-W electric power to the heat generating body 40, the temperature of the heat generating body 40, the 1st transmission layer 51, the 2nd transmission layer 52, a target object, and the process space 81 is measured. did. Table 1 shows the distance D, distance D / representative dimension L, and measured temperatures of Examples 1 to 10.

  FIG. 6 is a graph showing the relationship between the distance D / representative dimension L in Examples 1 to 10, the heating element 40, the first transmissive layer 51, the second transmissive layer 52, and the temperature of the object. As can be seen from Table 1 and FIG. 6, in each of Examples 1 to 10, the temperature difference between the heating element 40 and the filter unit 50 (the first transmissive layer 51 and the second transmissive layer 52) in use is increased. Was done. In addition, as the distance D / representative dimension L is larger, the temperature of the first transmission layer 51 is decreased, and the temperature difference between the heating element 40 and the first transmission layer 51 tends to increase. In Examples 2 to 10 in which the distance D / representative dimension L is 0.08 or more, the temperature increase of the first transmission layer 51 can be further suppressed, and the distance D / representative dimension L is 0.08 or more. Is more preferable. Further, in the region where the distance D / representative dimension L is 0.14 or less, the effect of suppressing the temperature increase of the first transmission layer 51 increases rapidly as the distance D / representative dimension L increases. When L was 0.14 or more, the temperature increase of the first transmission layer 51 could be further suppressed. Moreover, the tendency for the temperature of the heat generating body 40 to fall was seen, so that distance D / representative dimension L was large. In Examples 1 to 8 where the distance D / representative dimension L is 0.23 or less, the temperature drop of the heating element 40 can be further suppressed, and the distance D / representative dimension L can be 0.23 or less. It is considered more preferable. Further, when the distance D / representative dimension L is 0.19 or less, the temperature of the heating element 40 is kept at 600 ° C. or more, and the temperature decrease of the heating element 40 can be further suppressed. From the above, it is considered that the distance D / representative dimension L is preferably 0.08 or more and 0.14 or more, and preferably 0.23 or less and 0.19 or less. Further, in the example in which the first transmissive layer 51 was kept at a low temperature, the temperatures of the second transmissive layer 52, the object, and the processing space 81 tended to be kept at a low temperature.

  10, 10a Infrared heater, 20 heat generating part, 22 case, 23 reflecting member, 30 support plate, 31 front convex part, 32 rear convex part, 40 heating element, 41 folded end part, 47 first space, 50 filter part, 51 First transmission layer, 51a Substrate, 51b Upper coating layer, 51c Lower coating layer, 52 Second transmission layer, 60 Cooling case, 61 Refrigerant inlet / outlet, 63 Second space, 71 First fixing plate, 72 Second mounting Plate, 80 furnace body, 81 processing space, 85 belt conveyor, 90 semiconductor element, 92 coating film, 95 refrigerant supply source, 100 infrared processing apparatus.

Claims (8)

An infrared processing apparatus that performs infrared processing by emitting infrared rays to an object,
A heating element that emits infrared rays when heated, and a filter unit that has a reflection characteristic that reflects infrared rays in a predetermined reflection wavelength region and includes a first transmission layer that transmits at least part of infrared rays from the heating element; An infrared heater in which the heating element can absorb infrared rays in the reflection wavelength region, and a first space between the heating element and the first transmission layer is open to an external space;
A furnace body that is not in direct communication with the first space and forms a treatment space that is a space for performing the infrared treatment by infrared rays after being emitted from the heating element and transmitted through the filter unit;
Infrared processing device equipped with. The distance between the heating element and the first transmission layer is a distance D [cm], and a region in which the heating element is projected onto the first transmission layer in a direction perpendicular to the first transmission layer is defined as a projection area. The area of the smallest rectangular or circular area surrounding the entire projection area is defined as a heating element area S [cm ² ] (where 0 cm ² <heating element area S ≦ 400 cm ² ) and representative dimension L [cm] = 2 × √ ( When the heating element area S / π),
0.08 ≦ distance D / representative dimension L ≦ 0.23,
The infrared processing apparatus according to claim 1. The heating element and the first space are located outside the furnace body;
The infrared processing apparatus according to claim 1 or 2. The infrared processing device according to any one of claims 1 to 3,
A reflective member that is disposed on the side opposite to the first transmission layer as viewed from the heating element and reflects infrared rays in at least the reflection wavelength region;
Infrared processing device equipped with. The filter unit includes a second transmission layer that is disposed with a space between the first transmission layer and the second space and transmits at least a part of infrared rays transmitted through the first transmission layer among infrared rays from the heating element. And
The processing space formed by the furnace body is not in direct communication with the second space;
The infrared processing apparatus of any one of Claims 1-4. The infrared processing device according to claim 5,
A cooling means for cooling the filter part by circulating a refrigerant in the second space;
Infrared processing device equipped with. The heating element is a planar heating element that has a plane capable of emitting infrared rays toward the first transmission layer and capable of absorbing infrared rays in the reflection wavelength region.
The infrared processing apparatus of any one of Claims 1-6. A heating element that radiates infrared when heated,
A filter having a reflection characteristic that reflects infrared rays in a predetermined reflection wavelength region and is separated from the heating element by a first space and that transmits at least part of infrared rays from the heating element. And
With
The heating element can absorb infrared rays in the reflection wavelength region;
The first space is open to an external space;
The distance between the heating element and the first transmission layer is a distance D [cm], and a region in which the heating element is projected onto the first transmission layer in a direction perpendicular to the first transmission layer is defined as a projection area. The area of the smallest rectangular or circular area surrounding the entire projection area is defined as a heating element area S [cm ² ] (where 0 cm ² <heating element area S ≦ 400 cm ² ) and representative dimension L [cm] = 2 × √ ( When the heating element area S / π),
0.08 ≦ distance D / representative dimension L ≦ 0.23,
Infrared heater.

Images