JP2012142551A - Heat treatment method and apparatus - Google Patents

Abstract

An object of the present invention is to provide a heat treatment method and apparatus capable of efficiently sintering fine particles at a low temperature while preventing thermal deformation and damage due to heat.
PET (polyethylene terephthalate) coated with silver fine particles is fed into a chamber as an object to be processed (work) and accommodated. In step S2, the workpiece is accommodated in the chamber, and the workpiece is heated. Apart from the heat treatment in step S2, in step S2, a vacuum treatment is performed in parallel with the heat treatment in which the workpiece is treated in a vacuum in the chamber while the workpiece is accommodated. By combining this vacuum treatment with the heat treatment, the heating time can be reduced to a low temperature, and the fine particles can be efficiently sintered at a low temperature while preventing thermal deformation and damage due to heat.
[Selection] Figure 2

Description

  The present invention relates to a heat treatment method and apparatus for performing heat treatment on an object to be treated, and more particularly, a technique for sintering fine particles by performing heat treatment on an object to be treated on which metal fine particles are applied. About.

  Conventionally, metal pastes made of fine metal particles such as nano-sized silver and copper have been developed for the purpose of producing printed wiring boards. Specifically, metal fine particles are dissolved in a solvent, and a metal paste in which the fine particles are dispersed by a dispersant is applied to an object to be processed such as a substrate by a printing technique (inkjet or screen printing). Thereafter, the fine particles are sintered by dispersing the dispersant and the solvent by heat treatment.

  The heat treatment is performed under sintering conditions at 220 ° C. for 60 minutes when a glass substrate is used as an object to be processed using silver fine particles. Moreover, when using a base material thinner than a glass substrate as a to-be-processed object, in order to prevent a thermal deformation and damage by heat | fever, it is performed on the sintering conditions for 60 minutes at the low temperature of 120 to 150 degreeC.

  However, PET (polyethylene terephthalate) is actually deformed and damaged by heat even at 120 ° C to 150 ° C, and as a material for PET, it is required to sinter at around 100 ° C, and there is no appropriate material. It was. Therefore, plasma treatment using plasma generated by plasma discharge is applied, and the object to be processed (work) is placed in the plasma to perform the plasma treatment, and fine particles applied to the object to be processed such as PET are sintered at a low temperature. There exists a technique etc. (for example, refer to patent documents 1).

JP 2009-283547 A

  However, when performing the plasma processing using the method of Patent Document 1 described above, there are the following problems. That is, even if the plasma treatment is used, the sintering conditions are actually 120 ° C. to 150 ° C. and cannot be sintered at around 100 ° C. In Patent Document 1 described above, it is disclosed that the object to be processed is cooled to prevent thermal deformation or damage due to heat. However, the temperature may be uneven in the plasma processing unit (chamber) due to cooling. It has been found. Even if it is not cooled, it is difficult to make the plasma uniform, and heating with the heat energy of the plasma becomes unstable.

  Furthermore, in addition to the above-mentioned non-uniformity only by plasma processing, processing reproducibility is not stable due to a rapid temperature rise, plasma irradiation is performed for a long time, and damage to the processing object is large, and the surface of the processing object It has also been newly found that the substrate itself of the object to be processed is damaged because of the large temperature difference from the back surface.

  The present invention has been made in view of such circumstances, and provides a heat treatment method and apparatus capable of efficiently sintering fine particles at a low temperature while preventing thermal deformation and damage due to heat. For the purpose.

  As a result of earnest research to solve the above problems, the inventors have obtained the following knowledge.

  That is, in the conventional heat treatment, since the object to be treated is placed in the heat treatment part (chamber) and performed at atmospheric pressure, heat is uniformly distributed by a gas typified by air under atmospheric pressure, Compared with the plasma treatment, the temperature is considered to be uniform in the chamber. In view of this, a combination of the conventional heat treatment and another treatment is considered to be a clue to solving the above problem.

  Therefore, if the conventional heat treatment is called “pre-heat” and combined with another treatment after preheating, the heating time in the preheating is reduced to a low temperature, while preventing thermal deformation and damage due to heat. The inventors have found that it is possible to sinter fine particles efficiently at a low temperature. In other words, the idea is the opposite of the cooling in Patent Document 1 described above, and the idea of combining preheating and subsequent processing for heating at a low temperature, although actively heating, has been reached. As the subsequent processing, the vacuum processing for processing the processing object in a vacuum inside the heat treatment unit (chamber) in a state in which the processing target is accommodated, and the processing target as in the above-described Patent Document 1. Plasma processing for performing plasma processing is conceivable.

The present invention based on such knowledge has the following configuration.
That is, the heat treatment method according to the present invention is a heat treatment method in which heat treatment is performed on an object to which metal fine particles are applied to sinter the fine particles, and the heat treatment portion includes the heat treatment portion. A heat treatment process in which the object to be processed is accommodated and the heat treatment is performed on the object to be processed, and the object to be processed is processed in a vacuum inside the heat treatment unit while the object to be processed is accommodated. And a vacuum processing step.

  [Operation / Effect] According to the heat treatment method according to the present invention (the former invention), in the heat treatment process, the object to be treated is accommodated in the heat treatment part, and the object to be treated is subjected to the heat treatment. This corresponds to the conventional heat treatment process. Separately from this heat treatment process, the vacuum treatment process treats the object to be processed in a vacuum inside the heat treatment part in a state in which the object to be processed is accommodated. By combining this vacuum treatment process, it is possible to heat uniformly, improving the uniformity of treatment, shortening the heating time, so there is little damage to the object to be treated, the temperature difference between the front and back surfaces is reduced, and the object to be treated Damage to the substrate itself is also reduced. As a result, it is possible to efficiently sinter the fine particles at a low temperature while reducing the heating time to a low temperature and preventing thermal deformation and damage due to heat.

  In addition, a heat treatment method different from the heat treatment method according to the above-described invention (the former invention) is a heating method in which a heat treatment is performed on an object to which metal fine particles are applied to sinter the fine particles. A treatment method, wherein the object to be treated is accommodated in a heat treatment unit, the heat treatment process for performing the heat treatment on the object to be treated, and the object to be treated after the heat treatment process. And a plasma processing process for performing plasma processing.

  [Operation / Effect] According to the heat treatment method according to the present invention (the latter invention), as in the case of the invention having the vacuum treatment process (the former invention), the heat treatment process is performed inside the heat treatment section. The object is accommodated and the object to be processed is subjected to heat treatment, which corresponds to the process in the conventional heat treatment. In addition to the heat treatment process, a plasma treatment process for performing plasma treatment on an object to be processed is provided after the heat treatment process. By combining this plasma treatment process, it is possible to heat uniformly, improving the uniformity of treatment, shortening the heating time and plasma irradiation time, so there is little damage to the object to be processed, and the temperature difference between the front and back surfaces is reduced. In addition, damage to the substrate itself of the object to be processed is reduced. As a result, it is possible to efficiently sinter the fine particles at a low temperature while reducing the heating time to a low temperature and preventing thermal deformation and damage due to heat. Further, by performing the heating in advance of the plasma treatment, the temperature fluctuation range is reduced, and the reproducibility of the treatment can be improved.

  In the invention of the present invention (including the plasma processing process) described above (the latter invention), it is preferable to combine the above-described invention including the vacuum processing process (the former invention). That is, a vacuum processing process is performed in which the object to be processed is processed in vacuum while the object to be processed is accommodated, and the plasma processing in the above-described plasma processing process is performed after the vacuum processing process. Combining these vacuum treatment processes and plasma treatments improves the above processing uniformity, reduces heating time and plasma irradiation time, prevents damage to the object to be processed by reducing these times, front and back surface temperatures It is possible to further prevent damage to the substrate itself of the object to be processed by relaxing the difference. The fine particles can be efficiently sintered at a low temperature while reducing the heating time to a low temperature and preventing thermal deformation and damage due to heat.

  An example of the present invention (an example of the former) having the above-described vacuum treatment process performs heat treatment on an object to be processed in vacuum by performing the above-described heat treatment process and the above-described vacuum treatment process in parallel. . When a lamp heater is used in the heat treatment in the heat treatment process, for example, the heat is evenly distributed under vacuum even if the heat is not uniformly distributed by a gas typified by air at atmospheric pressure. The heat treatment process and the vacuum treatment process can be performed in parallel, and the heat treatment can be performed on the workpiece in vacuum.

  In another example (the latter example) of the present invention having the above-described vacuum treatment process, the above-described heat treatment process heats an object to be processed at atmospheric pressure, and the above-described vacuum treatment process includes the above-described vacuum treatment process. This is a evacuation process in which the inside of the heat treatment portion is depressurized to the above-described vacuum in a state in which the object to be processed is accommodated after the heat treatment process at atmospheric pressure. Unlike the former example (where the heat treatment process and the vacuum treatment process were performed in parallel), in the case of the latter example, the heat treatment process is performed by first heating the object to be processed at atmospheric pressure. (I.e., preheating), and after the heat treatment process at atmospheric pressure (i.e., preheating), the inside of the heat treatment unit is depressurized and evacuated (so-called "evacuation") in a state where the object to be processed is accommodated ). In the case of the latter, after the heat is uniformly distributed in the heat treatment process (preheating) with a gas typified by air at atmospheric pressure, the inside of the heat treatment unit is depressurized and evacuated. Since vacuuming is performed, heat can be uniformly distributed under vacuum to sinter the fine particles. Further, by performing heating in advance of vacuum processing, the temperature fluctuation range is reduced, and the reproducibility of processing can be improved.

  Moreover, the heat treatment apparatus according to the above-described invention is a heat treatment apparatus for performing heat treatment on a workpiece to which metal fine particles are applied to sinter the fine particles, and having the workpiece to be processed therein. A heat treatment unit that performs the heat treatment on the object to be processed, and processing the object to be processed in a vacuum inside the heat treatment unit in a state in which the object to be processed is accommodated. It is a feature.

  [Operation / Effect] According to the heat treatment apparatus of the present invention, the invention having the vacuum treatment process (the former invention) can be suitably implemented.

  Further, a heat treatment apparatus different from the heat treatment apparatus according to the above-described invention is a heat treatment apparatus for performing heat treatment on a workpiece to which metal fine particles are applied and sintering the fine particles. A heat treatment unit that houses the object to be treated and performs the heat treatment on the object to be treated, and a plasma treatment unit that performs a plasma treatment on the object to be treated after the heat treatment. It is characterized by providing.

  [Operation / Effect] According to the heat treatment apparatus of the present invention, the invention having the plasma treatment process (the latter invention) can be suitably implemented.

  In addition, a preferable example of the heat treatment apparatus according to these inventions described above includes a feeding unit that feeds an object to be processed, and performs processing while the object to be processed is fed by the feeding unit.

According to the heat treatment method of the present invention, in addition to the heat treatment process, a vacuum treatment process or a plasma treatment process is combined to reduce the heating time to a low temperature, while preventing thermal deformation and damage due to heat. The fine particles can be efficiently sintered at a low temperature.
Moreover, according to the heat processing apparatus which concerns on this invention, these heat processing methods can be implemented suitably.

1 is a schematic view of a heat treatment apparatus according to Example 1. FIG. 3 is a flowchart illustrating a series of flows of the heat treatment method according to the first embodiment. 6 is a schematic diagram of a heat treatment apparatus according to Embodiment 2. FIG. 6 is a flowchart showing a series of flows of a heat treatment method according to Embodiment 2. 6 is a schematic diagram of a heat treatment apparatus according to Example 3. FIG. 6 is a flowchart showing a series of flows of a heat treatment method according to Embodiment 3. 6 is a schematic view of a heat treatment apparatus according to Example 4. FIG. 10 is a flowchart showing a series of flows of a heat treatment method according to Embodiment 4. It is a graph (resistance value characteristic according to vacuum time) of resistance value change to vacuum time at the time of using a glass substrate as a processed object. It is a graph (volume resistivity characteristic according to vacuum time) of volume resistivity change with respect to vacuum time at the time of using a glass substrate as a processed object.

Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic diagram of a heat treatment apparatus according to the first embodiment. In Example 1, including Example 2 to be described later, PET that is fed by a roller will be described as an example of an object to be processed.

  In the first embodiment, the heat treatment apparatus includes a chamber 1 and a lamp heater 2 in the chamber 1 as shown in FIG. A vacuum pump 3 is provided in order to reduce the pressure inside the chamber 1 to make a vacuum. Although only one lamp heater 2 is shown in FIG. 1, a plurality of lamp heaters 2 may be provided. In Example 1, the chamber 1 corresponds to the heat treatment unit in the present invention.

  In addition, the heat treatment apparatus includes a roller 4 that feeds a long workpiece (workpiece) W into the chamber 1 in the direction indicated by the arrow in FIG. Although two rollers 4 are shown in FIG. 1, three or more rollers may be used. The workpiece W is PET (polyethylene terephthalate) coated with silver fine particles. In each example, silver fine particles are described as examples. However, as exemplified by gold and copper fine particles, metal fine particles that are usually used in printing technology (inkjet or screen printing) may be used. The fine particles to be applied are not particularly limited. The roller 4 corresponds to the feeding means in the present invention, and the workpiece W corresponds to the workpiece in the present invention.

  Then, the heat processing method which concerns on the present Example 1 is demonstrated with reference to FIG. FIG. 2 is a flowchart illustrating a series of flows of the heat treatment method according to the first embodiment. In FIG. 2, in the step S <b> 1, the inside of the chamber 1 is already evacuated by the vacuum pump 3, and has already reached a predetermined temperature (for example, about 100 ° C.) near the lamp heater 2 by the lamp heater 2. Explain that it is.

(Step S <b> 1) Feeding the Work As the work W, PET coated with silver fine particles is fed by the roller 4. Then, the workpiece W is fed into the lamp heater 2 provided between the two rollers 2.

(Step S2) Heat Treatment / Vacuum Treatment While the workpiece W is being fed, the workpiece W is heated by the lamp heater 2 so that the workpiece W is heated. Since the inside of the chamber 1 is in a vacuum, the workpiece W is processed in a vacuum. Therefore, this step S2 corresponds to the heat treatment process in the present invention, and also corresponds to the vacuum treatment process in the present invention. Then, the heat treatment process and the vacuum treatment process are performed in parallel.

(Step S3) Is there no work?
Step S2 is repeated while feeding the workpiece W until there is no workpiece W to be fed. When there are no more workpieces W to be sent, the series of heat treatment is finished.

  According to the heat treatment method according to the first embodiment, the heat treatment process in step S2 is performed by accommodating the workpiece (workpiece) W in the heat treatment section (chamber 1 in the first embodiment), The heat treatment is performed on W, which corresponds to the conventional heat treatment process. Apart from this heat treatment process, the vacuum process in step S2 processes the workpiece W in a vacuum in the chamber 1 in a state in which the workpiece W is accommodated. By combining this vacuum processing process, uniform heating can be achieved, the processing uniformity can be improved, and the heating time can be shortened, so there is little damage to the workpiece W, the temperature difference between the front and back surfaces is reduced, and the workpiece W base is reduced. Damage to the material itself is also reduced. As a result, the heating time is reduced to a low temperature (about 100 ° C. in the first embodiment), and the fine particles can be efficiently sintered at a low temperature while preventing thermal deformation and damage due to heat.

  In the first embodiment, the heat treatment process and the vacuum treatment process described above are performed in parallel in step S2, so that the heat treatment is performed on the workpiece W in a vacuum. When the lamp heater 2 is used in the heat treatment in the heat treatment process in step S2 as in the first embodiment, the heat is not uniformly distributed by a gas typified by air or the like under atmospheric pressure. In both cases, heat is uniformly distributed under vacuum, and the heat treatment process and the vacuum treatment process are performed in parallel in step S2, and the workpiece W can be heat-treated in vacuum.

  The heat treatment apparatus according to the first embodiment includes a chamber 1 that accommodates a workpiece W therein and performs heat treatment on the workpiece W. The workpiece W is accommodated in a vacuum while the workpiece W is accommodated. Is processing. According to the heat treatment apparatus according to the first embodiment having the above-described configuration, the heat treatment method according to the first embodiment having the vacuum treatment process in step S2 can be suitably performed.

  In the first embodiment, a feeding means (roller 4 in the first embodiment) for feeding the workpiece W is provided, and the processing is performed while the workpiece W is being fed by the roller 4.

Next, Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 3 is a schematic diagram of a heat treatment apparatus according to the second embodiment. In the second embodiment, as in the first embodiment described above, the PET to be sent by a roller will be described as an example of the object to be processed. In addition, the same code | symbol is attached | subjected about the same structure as Example 1 mentioned above, and the description is abbreviate | omitted.

  As in the first embodiment described above, the heat treatment apparatus includes a chamber 1, a lamp heater 2, a vacuum pump 3, and a roller 4, as shown in FIG. In the second embodiment, the heat treatment apparatus includes a supply flow path 5 for supplying a gas for plasma (indicated as “Gas” in FIG. 3), and electric power for plasma (indicated as “Power” in FIG. 3). And an electrode 6 for applying. Although two supply flow paths 5 are illustrated in FIG. 3, the number may be one or three or more. The gas for plasma is hydrogen, oxygen, or nitrogen, but any gas that is normally used in plasma as exemplified by rare gases such as argon (Ar) and helium (He) can be used. Is not particularly limited. Also in the second embodiment, the roller 4 corresponds to the feeding means in the present invention, and the workpiece W corresponds to the workpiece in the present invention.

However, the above-mentioned helium (He) and hydrogen (H ₂ ) are optimal for the gas for plasma. Since helium and hydrogen penetrate into the inside as compared with an element having a large molecular size, damage (damage) to the surface of the workpiece W is alleviated. In addition, in Patent Document 1 described above, it is disclosed that plasma is generated using only hydrogen, but plasma may be generated using not only hydrogen but also helium alone, or helium and hydrogen. Plasma may be generated using a mixed gas.

  Since hydrogen has a reducing effect, when plasma processing is performed on the workpiece W made of a material that easily oxidizes, the plasma processing can be performed on the workpiece W while preventing oxidation. However, in view of improving safety, it is more preferable to perform plasma treatment using helium alone or a mixed gas of helium and hydrogen than hydrogen alone. Even if it is a mixed gas of helium and hydrogen mixed with about 3% of the total hydrogen, there is a reduction effect, which is equivalent to when plasma treatment is performed using hydrogen alone (having an effect of mitigating damage) Processing can be performed. Therefore, a mixed gas of helium and hydrogen is effective for a metal that is easily oxidized such as copper (Cu). In addition, safety is improved as compared with hydrogen alone. In addition, a material that has an appropriate state depending on the amount of reduction may be reduced too much by hydrogen alone, and the amount of reduction can be reduced by adjusting the mixing ratio of helium and hydrogen.

  Further, in the case where plasma processing is performed using helium alone, the workpiece W made of a material that is not oxidized is equivalent to the plasma processing using hydrogen alone (with the effect of mitigating damage). It can be performed. In addition, safety is improved as compared with hydrogen alone.

  In the second embodiment, gas is supplied into the chamber 1 through the supply flow path 5, electric power is applied to the electrode 6, and plasma is generated in the chamber 1 by plasma discharge. Then, plasma processing is performed on the work W fed by the roller 4. Therefore, in the second embodiment, the chamber 1 corresponds to the heat treatment unit in the present invention and also corresponds to the plasma processing unit in the present invention. And the heat processing part of the chamber 1 also serves as a plasma processing part.

  Next, the heat treatment method according to the second embodiment will be described with reference to FIG. FIG. 4 is a flowchart illustrating a series of flows of the heat treatment method according to the second embodiment. Similar to FIG. 2 of the first embodiment described above, in FIG. 4 of the second embodiment, the chamber 1 is already evacuated by the vacuum pump 3 at the stage of step T1 and is already evacuated by the lamp heater 2. A description will be given assuming that a predetermined temperature (for example, about 100 ° C.) has already been reached in the vicinity of the lamp heater 2.

(Step T <b> 1) Feeding of Work As the work W, PET coated with silver fine particles is fed by the roller 4. This step T1 is the same as step S1 of FIG.

(Step T2) Heat Treatment / Vacuum Treatment While the workpiece W is being fed, the workpiece W is heated by the lamp heater 2 so that the workpiece W is heated. This step T2 is the same as step S2 of FIG. Therefore, also in the second embodiment, this step T2 corresponds to the heat treatment process in the present invention and also corresponds to the vacuum treatment process in the present invention. And also in the present Example 2, a heat processing process and a vacuum processing process are performed in parallel.

(Step T3) Is there no work?
Step T2 is repeated while feeding the workpiece W until there is no workpiece W to be fed. If there is no workpiece W to be sent, the process proceeds to the next step T4.

(Step T4) Plasma Generation Next, gas is supplied into the chamber 1 through the supply flow path 5 until a predetermined pressure (for example, about 20 Pascals) is reached. Then, a power of about 2 KW is applied to the electrode 6 to generate plasma in the chamber 1 by plasma discharge.

(Step T5) Refeeding of work The work W after the heat treatment / vacuum treatment in Step T2 is fed again by the roller 4. The work W after the heat treatment / vacuum treatment may be fed by a roller different from the roller 4 provided in the vicinity of the lamp heater 2.

(Step T6) Plasma processing The workpiece W is fed into the plasma in the chamber 1 while feeding the workpiece W, so that the workpiece W is subjected to plasma treatment. This step T6 corresponds to the plasma processing process in the present invention.

(Step T7) Is there no work?
Step T6 is repeatedly performed while feeding the workpiece W until there is no workpiece W to be fed. When there are no more workpieces W to be sent, the series of heat treatment is finished.

  According to the heat treatment method according to the second embodiment, similarly to the first embodiment including the vacuum treatment process in step S2, the heat treatment process in step T2 is performed by the heat treatment unit (chamber 1 in the second embodiment). The workpiece (work) W is accommodated in the interior of the workpiece, and the workpiece W is subjected to heat treatment, which corresponds to the conventional heat treatment process. Apart from this heat treatment process, a plasma treatment process in step T6 is performed separately from the heat treatment process, in which the workpiece W is subjected to plasma treatment after the heat treatment process in step T2. By combining this plasma treatment process, it is possible to heat uniformly, improving the uniformity of treatment, shortening the heating time and plasma irradiation time, so there is less damage to the workpiece W, and the temperature difference between the front and back surfaces is reduced. Damage to the substrate of the work W itself is also reduced. As a result, the heating time is reduced to a low temperature (about 100 ° C. in the second embodiment), and the fine particles can be efficiently sintered at a low temperature while preventing thermal deformation and damage due to heat. Further, by performing the heating in advance of the plasma treatment, the temperature fluctuation range is reduced, and the reproducibility of the treatment can be improved.

  In the second embodiment including the plasma processing process in step T6, the first embodiment including the vacuum processing process in step S2 is preferably combined. That is, a vacuum processing process (step T2) is performed in which the workpiece W is processed in a vacuum in the chamber 1 in a state in which the workpiece W is accommodated, and the plasma in the plasma processing process in the above-described step T6 after the vacuum processing process. Processing is in progress. By combining these vacuum processing steps and plasma processing, improvement of the above processing uniformity, reduction of heating time and plasma irradiation time, prevention of damage to the workpiece W due to reduction of these times, temperature difference between the front and back surfaces It is possible to further prevent the workpiece W from being damaged by the relaxation of the workpiece W. The fine particles can be efficiently sintered at a low temperature while reducing the heating time to a low temperature and preventing thermal deformation and damage due to heat.

  In the second embodiment, similarly to the first embodiment described above, the heat treatment process and the vacuum treatment process described above are performed in parallel at step T2, so that the heat treatment is performed on the workpiece W in a vacuum. After that, plasma processing is performed in the plasma processing process in step T6. When the lamp heater 2 is used as in the first and second embodiments, heat is uniformly distributed under vacuum, and the heat treatment process and the vacuum treatment process are performed in parallel in step S2, and then in step T6. Plasma processing is performed, and the heat treatment can be performed on the workpiece W in a vacuum.

  The heat treatment apparatus according to the second embodiment includes a chamber 1 that accommodates a work W therein and performs heat treatment on the work W, and performs plasma treatment on the work W after the heat treatment. (The same chamber 1 in this embodiment 2) is performed. According to the heat treatment apparatus according to the second embodiment having the above-described configuration, the heat treatment method according to the second embodiment having the plasma treatment process in step T6 can be suitably performed.

  In the second embodiment, the heat treatment unit also serves as the plasma processing unit as the chamber 1 and preferably performs the plasma treatment in a state where the heat-treated workpiece W is accommodated in the heat treatment unit of the chamber 1. Since the heat treatment unit also serves as the plasma treatment unit, the same heat treatment unit (that is, the chamber 1) can perform the plasma treatment subsequent to the heat treatment, and the heat treatment and the plasma treatment can be performed efficiently. Can be simplified.

  Similar to the above-described first embodiment, the second embodiment includes a feeding means (roller 4 in the second embodiment) that feeds the workpiece W, and performs processing while the workpiece W is fed by the roller 4. .

Next, Embodiment 3 of the present invention will be described with reference to the drawings.
FIG. 5 is a schematic diagram of a heat treatment apparatus according to the third embodiment. In Example 3, including Example 4 to be described later, PET to be processed as a workpiece will be described as an example. In addition, about the same structure as Example 1, 2 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As in the first and second embodiments described above, the heat treatment apparatus includes a chamber 1 and a vacuum pump 3 as shown in FIG. Unlike the first and second embodiments described above, in the third embodiment, the heat treatment apparatus includes an electric heater 12 instead of the lamp heater 2 of the first and second embodiments (see FIG. 1 or FIG. 3). Yes. Similar to the first embodiment described above, also in the third embodiment, the chamber 1 corresponds to the heat treatment unit in the present invention.

  In the third embodiment, the heat treatment apparatus includes a stage 14 on which a workpiece (workpiece) W for single wafer processing is placed. By providing this stage 14, the roller 4 of the first and second embodiments (see FIG. 1 or FIG. 3) is not required in the third embodiment. The electric heater 12 described above is provided in the stage 14. In FIG. 5, the electric heater 12 is provided in the stage 14, but the electric heater 12 is not necessarily provided in the stage 14, and the electric heater 12 may be provided in the vicinity of the workpiece W. The electric heater 12 is not necessarily required. The silicon carbide microwave heater made of silicon carbide (SiC) or the same lamp heater 2 as in the first and second embodiments (see FIG. 1 or FIG. 3). As illustrated in the above, the heating unit provided in the chamber 1 is not particularly limited as long as it is a heating unit normally used for heat treatment. The workpiece W corresponds to an object to be processed in the present invention.

  Then, the heat processing method which concerns on the present Example 3 is demonstrated with reference to FIG. FIG. 6 is a flowchart illustrating a series of flows of the heat treatment method according to the third embodiment. Since the electric heater 12 is used in the third embodiment without using the lamp heater 2 of the first and second embodiments (see FIG. 1 or FIG. 3), the above-described FIG. 2 and the second embodiment of the first embodiment are used. Unlike FIG. 4, FIG. 6 in the third embodiment will be described assuming that step U1 is first performed in order to uniformly distribute heat under atmospheric pressure.

(Step U1) Heating under atmospheric pressure First, the electric heater 12 is operated under atmospheric pressure to heat the chamber 1 under atmospheric pressure. By heating under atmospheric pressure, heat is evenly distributed under atmospheric pressure.

(Step U2) Placement of Work The PET coated with silver fine particles is placed on the stage 14 as the work W in a state where the electric heater 12 is continuously operated in the atmospheric pressure state.

(Step U3) Heat Treatment When the work W is placed on the stage 14 in a state where the electric heater 12 is continuously operated in the atmospheric pressure state, the electric heater 12 provided in the stage 14 heats the work W. The workpiece W is heated at atmospheric pressure. In the third embodiment, this step U3 corresponds to the heat treatment process in the present invention.

(Step U4) Vacuuming / Vacuum Processing The vacuum pump 3 is placed inside the chamber 1 while the electric heater 12 is continuously operated and the work W is placed on the stage 14 and accommodated in the chamber 1 after the heat treatment. The vacuum is reduced to reduce the pressure to a vacuum. Due to this evacuation, the inside of the chamber 1 is evacuated, and the workpiece W is processed in a vacuum. Therefore, this step U4 corresponds to the vacuum processing process in the present invention, and also corresponds to the vacuuming process in the present invention. Then, by continuing to operate the electric heater 12 in a vacuum state, the heat treatment is continuously performed in a vacuum state.

(Step U5) Is there no work?
After the heat treatment in Steps U3 and U4, the workpiece W after the vacuum treatment in Step U4 is further lifted from the chamber 1. Until there is no workpiece W to be subjected to the single wafer processing, the single wafer processing is performed by returning from the vacuum to the atmospheric pressure and returning to step U1 to repeat steps U1 to U5. That is, the single wafer processing is performed by repeatedly placing the next workpiece W on the stage 14 after performing the processing in steps U1 to U5. When there is no work W to be subjected to the single wafer processing, the series of heating processes is terminated. When the next workpiece W is placed on the stage 14, it is not always necessary to return from the vacuum to the atmospheric pressure and return to step U 1 if there is no effect on the heat uniformity, and return from step U 5 to step U 2. Steps U2 to U5 may be repeated.

  According to the heat treatment method according to the third embodiment, similarly to the first and second embodiments including the vacuum treatment process at step S2 or step T2, the heat treatment process at step U3 is performed by the heat treatment unit (this embodiment). In Example 3, the workpiece (workpiece) W is accommodated in the chamber 1), and the workpiece W is subjected to heat treatment, which corresponds to the conventional heat treatment process. Apart from this heat treatment process, the vacuum process in step U4 processes the workpiece W in a vacuum in the chamber 1 in a state in which the workpiece W is accommodated. By combining this vacuum processing process, uniform heating can be achieved, the processing uniformity can be improved, and the heating time can be shortened, so there is little damage to the workpiece W, the temperature difference between the front and back surfaces is reduced, and the workpiece W base is reduced. Damage to the material itself is also reduced. As a result, the heating time can be reduced to a low temperature (about 100 ° C. in the third embodiment), and fine particles can be efficiently sintered at a low temperature while preventing thermal deformation and damage due to heat.

  In the third embodiment, the heat treatment process in step U3 heats the workpiece W at atmospheric pressure, and the vacuum treatment process in step U4 is performed after the above-described heat treatment process at atmospheric pressure. This is a evacuation process in which the inside of the chamber 1 is depressurized to contain the above-described vacuum while W is accommodated. Unlike the first and second embodiments in which the heat treatment process and the vacuum treatment process are performed in parallel, in the case of the present third embodiment, the heat treatment process in Step U3 heats the workpiece W at atmospheric pressure. The process is performed first (that is, preheating is performed), and after the heat treatment process at atmospheric pressure (that is, preheating) in Step U3, the inside of the chamber 1 is evacuated and vacuumed in a state where the workpiece W is accommodated. In step U4. In the case of Example 3, after the heat is uniformly distributed in the heat treatment process (preheating) with a gas typified by air under atmospheric pressure, the inside of the heat treatment unit is depressurized and evacuated. Since vacuuming is performed, fine particles can be sintered by uniformly distributing heat under vacuum. Further, by performing heating in advance of vacuum processing, the temperature fluctuation range is reduced, and the reproducibility of processing can be improved.

  In FIG. 6 of the third embodiment, the evacuation process is performed in step U4 in the middle of the heat treatment process (including step U4) at atmospheric pressure, and the heat treatment is continuously performed in a vacuum state.

  As in the first embodiment described above, the heat treatment apparatus according to the third embodiment includes the chamber 1 in which the workpiece W is housed and heat-treats the workpiece W, and the workpiece W is housed. The workpiece W is processed in a vacuum inside the chamber 1. According to the heat treatment apparatus according to the third embodiment having the above-described configuration, the heat treatment method according to the third embodiment having the vacuum processing process in step U4 can be suitably performed.

  Unlike the above-described first and second embodiments, in the third embodiment, a mounting table (the stage 14 in the third embodiment) on which the work W is placed is disposed inside the chamber 1, and the target work W is placed. On the other hand, the single wafer processing is performed by repeatedly placing the next workpiece W on the stage 14 after each processing.

Next, Embodiment 4 of the present invention will be described with reference to the drawings.
FIG. 7 is a schematic diagram of a heat treatment apparatus according to the fourth embodiment. In the fourth embodiment, as in the third embodiment described above, PET to be processed as a processing object will be described as an example. In addition, about the same structure as Examples 1-3 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As in the first to third embodiments, the heat treatment apparatus includes a chamber 1 and a vacuum pump 3 as shown in FIG. Similar to the third embodiment described above, in the fourth embodiment, the heat treatment apparatus includes an electric heater 12 instead of the lamp heater 2 of the first and second embodiments (see FIG. 1 or FIG. 3).

  Similarly to the above-described third embodiment, the fourth embodiment includes a stage 14 on which a workpiece (workpiece) W for single wafer processing is placed. By providing this stage 14, the rollers 4 of the first and second embodiments (see FIG. 1 or FIG. 3) are not necessary in the fourth embodiment. The electric heater 12 described above is provided in the stage 14. Similar to the third embodiment described above, also in the fourth embodiment, the workpiece W corresponds to the workpiece in the present invention.

  Similar to the second embodiment described above, in the fourth embodiment, the heat treatment apparatus includes a supply flow path 5 and an electrode 6 in order to perform plasma processing. Similar to the second embodiment described above, also in the fourth embodiment, the chamber 1 corresponds to the heat treatment section in the present invention and also corresponds to the plasma processing section in the present invention. And the heat processing part of the chamber 1 also serves as a plasma processing part.

  As is apparent from the above description, in the fourth embodiment, the structure of the second embodiment (see FIG. 3) including the supply flow path 5 and the electrode 6 for performing plasma processing, and the lamp heater 2 (see FIG. 3). 1 (see FIG. 3), an electric heater 12 is provided, and the roller 4 (see FIG. 1 or FIG. 3) is replaced with a stage 14 for sheet processing (see FIG. 5). (See also). Therefore, when the structure of Example 2 in FIG. 3 and the structure of Example 3 in FIG. 5 are combined, the structure of Example 4 in FIG. 7 is obtained.

  Then, the heat processing method which concerns on the present Example 4 is demonstrated with reference to FIG. FIG. 8 is a flowchart illustrating a series of flows of the heat treatment method according to the fourth embodiment. Similar to FIG. 6 of the third embodiment described above, FIG. 8 of the fourth embodiment will be described on the assumption that step V1 is first performed in order to uniformly distribute heat at atmospheric pressure.

(Step V1) Heating under atmospheric pressure First, the electric heater 12 is operated under atmospheric pressure to heat the chamber 1 under atmospheric pressure, thereby uniformly distributing heat under atmospheric pressure. This step V1 is the same as step U1 of FIG.

(Step V2) Placement of Work The PET coated with silver fine particles is placed on the stage 14 as the work W in a state where the electric heater 12 is continuously operated in the atmospheric pressure state. This step V2 is the same as step U2 of FIG.

(Step V3) Heat Treatment With the electric heater 12 kept operating at atmospheric pressure, the workpiece W is placed on the stage 14 to heat the workpiece W at atmospheric pressure. This step V3 is the same as step U3 of FIG. Therefore, similarly to the above-described third embodiment, also in the fourth embodiment, this step V3 corresponds to the heat treatment process in the present invention.

(Step V4) Vacuuming / Vacuum Processing With the electric heater 12 kept operating, vacuuming is performed with the work W placed on the stage 14 and accommodated in the chamber 1 after the heat treatment. This step V4 is the same as step U4 of FIG. Therefore, similarly to the third embodiment described above, also in the fourth embodiment, this step V4 corresponds to the vacuum processing process in the present invention and also corresponds to the evacuation process in the present invention. Then, the heat treatment is continued in a vacuum state.

(Step V5) Plasma Generation Next, after the heat treatment in steps V3 and V4, and further, the work W after the vacuum treatment in step V4 is placed on the stage 14 and accommodated in the chamber 1, the supply flow Gas is supplied through the passage 5 into the chamber 1 until a predetermined pressure (for example, about 20 Pascals) is reached. Then, a power of about 2 KW is applied to the electrode 6 to generate plasma in the chamber 1 by plasma discharge. When the work W is accommodated in the chamber 1 and any trouble occurs in the work W or plasma generation, the work W may be temporarily lifted from the chamber 1 as necessary until the next step V6. .

(Step V6) Plasma Treatment Plasma treatment is performed on the workpiece W while the workpiece W is placed on the stage 14 and accommodated in the chamber 1. This step V6 corresponds to the plasma processing process in the present invention.

(Step V7) Is there no work?
The workpiece W after the plasma processing unit in step V7 is lifted from the chamber 1. Until there is no workpiece W to be subjected to the single wafer processing, the single wafer processing is performed in which the plasma state is returned to the atmospheric pressure, the process returns to Step V1, and Steps V1 to V7 are repeated. That is, the single wafer processing is performed by repeatedly placing the next workpiece W on the stage 14 after performing the processing in steps V1 to V7. When there is no work W to be subjected to the single wafer processing, the series of heating processes is terminated. If heating under atmospheric pressure in step V1 can be substituted with a gas for plasma, the gas is returned to atmospheric pressure without degassing, and only the application of power to the electrode 6 is stopped. Just do it.

  According to the heat treatment method according to the fourth embodiment, as in the first and second embodiments including the vacuum treatment process at step S2 or step T2, the heat treatment process at step V3 is performed by the heat treatment unit (this embodiment). In Example 4, the workpiece (work) W is accommodated in the chamber 1), and the workpiece W is subjected to heat treatment, which corresponds to the conventional heat treatment process. Apart from this heat treatment process, similarly to the above-described second embodiment, a plasma treatment process in step V6 is performed in which the plasma treatment is performed on the workpiece W after the heat treatment process in step V3. By combining this plasma treatment process, it is possible to heat uniformly, improving the uniformity of treatment, shortening the heating time and plasma irradiation time, so there is less damage to the workpiece W, and the temperature difference between the front and back surfaces is reduced. Damage to the substrate of the work W itself is also reduced. As a result, the heating time is reduced to a low temperature (about 100 ° C. in the fourth embodiment), and the fine particles can be efficiently sintered at a low temperature while preventing thermal deformation and damage due to heat. Further, by performing the heating in advance of the plasma treatment, the temperature fluctuation range is reduced, and the reproducibility of the treatment can be improved.

  In the fourth embodiment including the plasma processing process in step V6, the first embodiment including the vacuum processing process in step S2 is preferably combined as in the second embodiment described above. That is, a vacuum processing process (step V4) is performed in which the workpiece W is processed in a vacuum in the chamber 1 in a state in which the workpiece W is accommodated, and the plasma in the plasma processing process in the above-described step V6 after the vacuum processing process. Processing is in progress. By combining these vacuum processing steps and plasma processing, improvement of the above processing uniformity, reduction of heating time and plasma irradiation time, prevention of damage to the workpiece W due to reduction of these times, temperature difference between the front and back surfaces It is possible to further prevent the workpiece W from being damaged by the relaxation of the workpiece W. The fine particles can be efficiently sintered at a low temperature while reducing the heating time to a low temperature and preventing thermal deformation and damage due to heat.

  Similar to the third embodiment described above, in the fourth embodiment, the heat treatment process in step V3 is performed on the workpiece W at atmospheric pressure, and the vacuum treatment process in step V4 is performed using the atmospheric pressure described above. This is a vacuuming process in which the inside of the chamber 1 is depressurized and the above-described vacuum is made in a state where the workpiece W is accommodated after the heat treatment process in FIG. After the evacuation process, the plasma process in the plasma process in step V6 is performed. In the case of the fourth embodiment, similarly to the third embodiment described above, after heat is uniformly distributed in the heat treatment process (preheating) with a gas typified by air or the like under atmospheric pressure, the heat treatment is performed. Since the inside of the section is evacuated to reduce the vacuum, heat can be uniformly distributed under vacuum to sinter the fine particles. Further, by performing heating in advance of vacuum processing, the temperature fluctuation range is reduced, and the reproducibility of processing can be improved.

  As in the third embodiment, in FIG. 8 of the fourth embodiment, the vacuum process is performed in step V4 in the middle of the heating process (including step V4) at atmospheric pressure, and heating is performed in a vacuum state. Processing continues. After that, plasma processing is performed in the plasma processing process in step V6.

  Similar to the second embodiment described above, the heat treatment apparatus according to the fourth embodiment includes the chamber 1 that accommodates the work W therein and performs the heat treatment on the work W, and the work after the heat treatment is provided. Plasma processing is performed on W by the plasma processing unit (the same chamber 1 in the fourth embodiment). According to the heat treatment apparatus according to the fourth embodiment having the above-described configuration, the heat treatment method according to the fourth embodiment including the plasma treatment process in Step V6 can be suitably performed.

  Similar to the second embodiment described above, in the fourth embodiment, the heat processing unit also serves as the plasma processing unit as the chamber 1, and preferably the work W after the heat processing is accommodated in the heat processing unit of the chamber 1. Plasma treatment is performed in the state. Since the heat treatment unit also serves as the plasma treatment unit, the same heat treatment unit (that is, the chamber 1) can perform the plasma treatment subsequent to the heat treatment, and the heat treatment and the plasma treatment can be performed efficiently. Can be simplified.

  Similar to the third embodiment described above, in the fourth embodiment, a mounting table (the stage 14 in the fourth embodiment) on which the work W is mounted is disposed inside the chamber 1 and the target work W is processed. After each of the above, the single wafer processing is performed by repeatedly placing the next workpiece W on the stage 14.

[Experimental result]
Here, a change in resistance value and a change in volume resistivity when a glass substrate is used as the object to be processed are confirmed by experiments. An experimental result is demonstrated with reference to FIG. 9 and FIG. FIG. 9 is a graph of resistance value change with respect to vacuum time when a glass substrate is used as an object to be processed (resistance value characteristic by vacuum time), and FIG. 10 is a vacuum when a glass substrate is used as an object to be processed. It is a graph (volume resistivity characteristic according to vacuum time) of volume resistivity change with respect to time.

  As shown in FIG. 9 and FIG. 10, when plasma evacuation was performed after preheating as in Example 3 without performing plasma treatment as in Examples 2 and 4 (in FIG. 9 and FIG. 10, “ Preheat + vacuum only ”), heating at 170 ° C. by heating the heater. Evacuation is started about 8 minutes after the heater is activated (indicated as “heater ON” in FIGS. 9 and 10).

  Until the start of evacuation, both the resistance value and the volume resistivity increase as shown in FIGS. 9 and 10. However, it is confirmed that both the resistance value and the volume resistivity decrease when evacuation is started. Further, after about 38 minutes, it was confirmed that the resistance value decreased to 214.7 [Ω] as shown in FIG. 9, and the volume resistivity decreased to 5.58 [mΩ · cm] as shown in FIG. Yes.

  Therefore, in the conventional heat treatment, the glass substrate was sintered at 220 ° C. for 60 minutes, but when pre-heating and vacuuming was performed, the sintering was performed at 170 ° C. for about 35 minutes. Even under the conditions, both the resistance value and the volume resistivity can be reduced, and the heating time including the vacuum time can be reduced and the sintering can be performed at a low temperature.

  Further, when the plasma processing is combined as in the second and fourth embodiments, as compared with the case where only the conventional plasma processing is performed, the plasma irradiation time is shortened as described above, and the plasma processing time is shortened. It also has the effect of being finished. In addition, when a magnetron is used in plasma processing, there is an effect that the life of the magnetron is extended by shortening the plasma processing time.

  Further, as described in the problem, it is difficult to make the plasma uniform only by the conventional plasma treatment, and the heating with the heat energy of the plasma becomes unstable. In each embodiment, a heater (lamp heater or The electric heater) can be disposed as close as possible to the object to be processed (work), and there is also an effect that it can be heated uniformly.

  Also, when the temperature may be high, such as a glass substrate, it is realized only by a vacuum and a heater as in Examples 1 and 3 without combining plasma processing as in Examples 2 and 4. Therefore, it is possible to perform a large amount of processing and reduce the cost. In addition, in the case of an object to be processed having a large area, it can be realized only by the conventional plasma processing, but in the case of each embodiment, both of the processing can be realized regardless of the large area and the small area. There is also an effect.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) In each of the above-described embodiments, PET (polyethylene terephthalate) coated with silver fine particles is taken as an example of the object to be processed (work). However, as illustrated in a glass substrate or the like, The processed product is not particularly limited.

  (2) In the above-described Examples 2 and 4, the plasma treatment process was performed after the vacuum treatment process, but the plasma treatment after the heat treatment process in the preheating and the heat treatment process was performed without performing the vacuum treatment. Only the process may be performed.

  (3) In Examples 3 and 4 described above, the evacuation process was performed in the middle of the heat treatment process at atmospheric pressure, and the heat treatment was continued in a vacuum state. However, in the heat treatment process at atmospheric pressure, You may perform the above-mentioned vacuuming process, after stopping heating with respect to a to-be-processed object (work). Even when the vacuuming process is performed after heating is stopped for the workpiece (work) in the heat treatment process at atmospheric pressure, the residual heat inside the heat treatment section causes the workpiece (work) to be processed. The heat treatment is substantially performed under vacuum.

  (4) In the above-described Examples 2 and 4, the heat treatment unit also used the plasma treatment unit as the chamber 1, but the heat treatment unit and the plasma treatment unit are configured as separate chambers, Processing may be performed.

DESCRIPTION OF SYMBOLS 1 ... Chamber 4 ... Roller 14 ... Stage W ... Workpiece (to-be-processed object)

Claims (11)

A heat treatment method for performing heat treatment on an object to be coated with metal fine particles, and sintering the fine particles,
A heat treatment process in which the object to be treated is accommodated in a heat treatment unit, and the heat treatment is performed on the object to be treated;
And a vacuum processing step of processing the object to be processed in a vacuum inside the heat processing unit in a state in which the object to be processed is accommodated. A heat treatment method for performing heat treatment on an object to be coated with metal fine particles, and sintering the fine particles,
A heat treatment process in which the object to be treated is accommodated in a heat treatment unit, and the heat treatment is performed on the object to be treated;
And a plasma treatment process for performing plasma treatment on the workpiece after the heat treatment process. In the heat processing method of Claim 2,
A vacuum processing step of processing the processing object in a vacuum inside the heat treatment unit in a state in which the processing object is accommodated;
A heat treatment method comprising performing the plasma treatment in the plasma treatment process after the vacuum treatment process. In the heat processing method of Claim 1 or Claim 3,
A heat treatment method, wherein the heat treatment is performed on the object to be processed in the vacuum by performing the heat treatment process and the vacuum treatment process in parallel. In the heat processing method of Claim 1 or Claim 3,
In the heat treatment process, the heat treatment is performed on the workpiece at atmospheric pressure,
The vacuum treatment process is a evacuation process in which the inside of the heat treatment unit is depressurized and vacuumed in a state in which the workpiece is accommodated after the heat treatment process at the atmospheric pressure. Heat treatment method. In the heat processing method of Claim 2 or Claim 3,
A heat treatment method, wherein the plasma treatment is performed using hydrogen alone. In the heat processing method of Claim 2 or Claim 3,
A heat treatment method, wherein the plasma treatment is performed using helium alone. In the heat processing method of Claim 2 or Claim 3,
A heat treatment method, wherein the plasma treatment is performed using a mixed gas of helium and hydrogen. A heat treatment apparatus for performing heat treatment on an object to be coated with metal fine particles and sintering the fine particles,
A heat treatment unit that houses the object to be processed and performs the heat treatment on the object to be processed,
A heat treatment apparatus, wherein the object to be processed is processed in a vacuum inside the heat treatment unit in a state where the object to be processed is accommodated. A heat treatment apparatus for performing heat treatment on an object to be coated with metal fine particles and sintering the fine particles,
A heat treatment unit for accommodating the object to be processed therein and performing the heat treatment on the object to be processed;
A heat treatment apparatus comprising: a plasma treatment unit that performs a plasma treatment on the workpiece after the heat treatment. In the heat processing apparatus of Claim 9 or Claim 10,
A feeding means for feeding the object to be processed;
A heat treatment apparatus, wherein the processing is performed while the workpiece is being fed by the feeding means.