JP4445476B2 - Heat treatment furnace and solar cell - Google Patents

Description

  The present invention relates to a heat treatment furnace used for heat treatment of a solar battery cell and the like, and a solar battery cell manufactured by the heat treatment furnace.

  In the manufacture of solar cells, conductive electrode materials are pasted on the front and back surfaces of a substrate and printed in a predetermined pattern, and then heat-treated (dried and dried) while moving in a heat-treating furnace continuously or intermittently. There is a step of firing. Usually, in a heat treatment furnace used for such heat treatment, a drying region for drying the material to be heat treated and a firing region for firing the material to be heat treated are sequentially provided from the inlet side to the outlet side of the furnace. The material to be heat-treated is dried while being transported through the drying region, then is fired while being transported through the firing region, and is then carried out of the furnace.

  As a transport mechanism for transporting an object to be heat treated in a heat treatment furnace, a mesh belt conveyor is widely used when the object to be heat treated is a solar battery cell (see, for example, Patent Document 1). However, the mesh belt conveyor has a very large heat capacity of the mesh belt itself, and energy equal to or higher than the energy required for heating the object to be heat-treated is consumed for heating the mesh belt. In addition, baking after drying in solar cells, that is, baking of electrode materials made of aluminum or silver onto the substrate surface, is quickly heated to about 800 ° C. in a short time, and then rapidly cooled. In the mesh belt conveyor having a large heat capacity, it is difficult to realize such an ideal heat treatment state.

  Recently, the heat capacity is smaller than that of mesh belt conveyors, and rapid heating and cooling is possible. Therefore, tension is applied to the walking beam and wire such as wire, and the wire is like a walking beam. A transport mechanism that performs a transport operation has also been used (see, for example, Patent Documents 2 to 5). However, in a heat treatment furnace using these transfer mechanisms, since at least a part of a transfer part (beam or wire) on which the object to be heat-treated is placed and moved is always in the furnace, Thus, when cracks occur in the heat-treated material due to thermal shock during firing on the part existing in the furnace, it is difficult to remove the broken pieces from the transport section. For this reason, the heater must be turned off and the operation of the furnace must be stopped for a long time, which has had a great effect on productivity.

JP 2002-203888 A JP 2003-261222 A JP 2004-286425 A JP 2004-286426 A JP 2004-286434 A

  The present invention has been made in view of such a conventional situation. The object of the present invention is low energy consumption, and it is easy to obtain an ideal heat treatment state of an object to be heat treated. Heat treatment that can easily remove debris from the transport section without stopping the operation of the furnace or just stopping for a short time when cracking of the heat-treated material occurs on the transport section inside To provide a furnace.

  In order to achieve the above object, according to the present invention, the following heat treatment furnace and solar battery cell are provided.

[1] A heat treatment furnace that performs a predetermined heat treatment on the heat treatment object while conveying the heat treatment object, and as a transport mechanism for transporting the heat treatment object, the heat treatment object is put into the furnace, An input side transport mechanism for transporting to a predetermined position in the furnace; and a unloading side transport mechanism for receiving the heat-treated material from the input side transport mechanism at the predetermined position and transporting from the predetermined position to the outside of the furnace. The transporting mechanism and the unloading-side transport mechanism are configured to transport the object to be heat-treated by a cantilevered beam that periodically operates in a predetermined cycle, and the input-side transporting mechanism and the unloading-side transporting mechanism. A heat treatment furnace in which the entire beam is completely out of the furnace at the time of loading and unloading the object to be heat treated.

[2] A drying region for drying the material to be heat-treated and a firing region for baking the material to be heat-treated are provided in this order from the inlet side to the outlet side of the furnace, and the material to be heat-treated is provided in the drying region. The heat treatment furnace according to [1], wherein the transfer is performed by the input-side transport mechanism, and the workpiece is transported by the unloading-side transport mechanism in the firing region.

[3] The heat treatment furnace according to [1] or [2], wherein a support roller that supports the beam in contact with the lower side of the beam is provided.

[4] A holding jig for holding the heat-treated object in contact with only the edge of the object to be heat-treated is attached to the beam of the carry-out side transport mechanism. The heat treatment furnace according to any one of [1] to [3], wherein the width of the portion in contact with the heat-treated product is 2 mm or less.

[5] The cycle time of one operation of the loading side transport mechanism and the unloading side transport mechanism is any one of the above [1] to [4], which is an integral multiple of the cycle time of the other operation. Heat treatment furnace.

[6] A heater is provided as a heating means in the furnace, and the heater is positioned above the object to be heat-treated and does not overlap with a region through which the object to be heat-treated is viewed from directly above the furnace. The heat treatment furnace according to any one of [1] to [5], which is provided at such a position.

[7] In the firing region, a rectifying plate extending downward from the furnace ceiling portion is provided at a position between the heater and the passage region of the heat-treated material when viewed from directly above the furnace, and above the heater. The heat treatment furnace as set forth in [6], wherein an air supply port is provided at the top and an exhaust port is provided above a region through which the heat-treated object passes.

[8] The above [1] to [7], wherein the height L from the inner bottom surface of the furnace to the transfer surface satisfies L ≧ 1.3 × D in relation to the maximum dimension D of the workpiece. The heat treatment furnace according to any one of the above.

[9] A solar battery cell manufactured using the heat treatment furnace according to any one of [1] to [8].

  The heat treatment furnace of the present invention uses a beam having a smaller heat capacity than the mesh belt as a transport mechanism, so that it consumes less energy and is easy to heat and cool quickly, making it ideal for the object to be heat treated. Easy to obtain heat treatment. Furthermore, since the beam that moves with the object to be heat-treated is completely out of the furnace at the time of loading and unloading the object to be heat-treated, the heat-treated object is cracked on the beam inside the furnace. In this case, it is possible to easily remove debris from the beam outside the furnace without stopping the operation of the furnace or just stopping for a short time. Further, since the solar battery cell of the present invention is manufactured in an ideal heat treatment state in the heat treatment furnace as described above, it is compared with the solar battery cell produced in a heat treatment furnace using a mesh belt as a transport mechanism. Therefore, good characteristics (such as power generation capacity) can be expected.

  As described above, the heat treatment furnace of the present invention is a heat treatment furnace that performs a predetermined heat treatment on the object to be heat treated while conveying the object to be heat treated, and the heat treatment furnace serves as a conveyance mechanism for conveying the object to be heat treated. A loading-side transfer mechanism for loading an object into the furnace and transporting it to a predetermined position in the furnace; and a unloading side for receiving the material to be heat-treated from the charging-side transfer mechanism at the predetermined position and transporting it from the predetermined position to the outside of the furnace A transfer mechanism, wherein the input side transfer mechanism and the output side transfer mechanism transfer the object to be heat-treated by a cantilever beam that periodically operates in a predetermined cycle. The entire beam of the transfer mechanism and the unload-side transfer mechanism is configured to be completely out of the furnace when the workpiece is put in and taken out.

  Hereinafter, representative embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and is within the scope of the present invention. It should be understood that design changes, improvements, and the like can be made as appropriate based on the general knowledge of vendors.

  FIGS. 1 to 3 are schematic cross-sectional views showing an example of an embodiment of a heat treatment furnace according to the present invention in a cross-section along the conveying direction, FIG. 1 is a state when an object to be heat-treated is charged, and FIG. FIG. 3 shows a state at the time of delivery from the input side transport mechanism to the carry-out side transport mechanism, and FIG.

  The heat treatment furnace of this embodiment is provided with a drying region 9 for drying the object to be heat-treated 51 and a baking region 19 for baking the object to be heat-treated 51 in this order from the inlet side to the outlet side of the furnace, and drying. In the region 9, the workpiece 51 is transported by the input-side transport mechanism, and in the firing region 19, the workpiece 51 is transported by the unloading-side transport mechanism. The heat treatment furnace having such a configuration has an advantage that the heat treatment object can be dried and fired in a single furnace.

  The input side transport mechanism provided on the entrance side of the furnace includes a beam 22 having a cantilever structure extending in the horizontal direction and having one end supported by a beam support 21. The beam support 21 is configured to periodically repeat the ascending, advancing, descending, and retreating operations with a predetermined stroke by a driving mechanism (not shown). Perform periodic operation.

  In the vicinity of the tip of the beam 22, a holding jig 23 for holding the object to be heat-treated 51 in contact with only the edge of the object to be heat-treated 51 is mounted. When the object to be heat-treated 51 is a solar battery cell, an electrode material obtained by kneading metal particles mainly composed of silver or aluminum with an organic solvent or a polymer resin to form a paste is not limited to the surface of the substrate. If the back surface is also printed by screen printing and the beam 22 is in direct contact with it in the dry region 9, the printed surface may be peeled off at the contact area, or scratches or burn marks may be attached. In addition to adversely affecting the performance and appearance of the heat-treated product 51, the peeled printed surface may adhere to the beam 22 and contaminate the transport system. For this reason, it is desirable to use the holding jig 23 as described above and limit the contact of the transport mechanism to the heat-treated object 51 only to the edge of the heat-treated object 51 on which no electrode material is printed.

  A support roller 24 that supports the beam 22 in contact with the lower side of the beam 22 is provided near the end of the beam 22 opposite to the side supported by the beam support 21. Since the beam 22 is a cantilever structure and the center of gravity is eccentric, it is preferable to provide a support roller 24 that can rotate in this way to support the beam 22 from below and stabilize the beam 22.

  The carry-out side transport mechanism provided on the outlet side of the furnace has a beam 32 having a cantilever structure extending in the horizontal direction and having one end supported by a beam support 31. The beam support 31 is configured to periodically repeat the forward and backward movements with a predetermined stroke by a driving mechanism (not shown) in a predetermined cycle, whereby the beam 32 also performs the same periodic movement. Do.

  In the vicinity of the tip of the beam 32, a holding jig 33 for holding the workpiece 51 in contact with only the edge of the workpiece 51 is mounted. When the object to be heat-treated 51 is a solar battery cell, as described above, the electrode material mainly composed of aluminum is also printed on the back surface of the substrate, and the reactivity in the electrode material is high. If aluminum is in direct contact with the beam 32 at a high temperature in the fired region 19, there is a possibility that the performance of the article 51 to be heat-treated or the appearance thereof may be deteriorated due to the reaction between the two at the contact portion. For this reason, it is desirable to use the holding jig 33 as described above and limit the contact of the transport mechanism to the heat-treated object only to the edge of the heat-treated object 51 on which no electrode material is printed.

  In the same manner as the input side transport mechanism, in the unload side transport mechanism, the beam 32 is in contact with the lower side of the beam 32 near the end of the beam 32 opposite to the side supported by the beam support 31. A support roller 34 is provided to support 22. Since the beam 32 is a cantilever structure and the center of gravity is decentered, it is preferable to provide a support roller 34 that can rotate in this way to support the beam 32 from below and to stabilize the beam 32.

  In addition to these transfer mechanisms, the heat treatment furnace according to the present embodiment includes a take-out mechanism that receives, from the carry-out side transfer mechanism, the heat-treated object 51 transferred to the outside of the furnace through the exit of the furnace by the carry-out side transfer mechanism. The take-out mechanism has a beam 42 having a cantilever structure extending in the horizontal direction and having one end supported by a beam support 41. The beam support 41 is configured to periodically repeat the ascending and descending operations with a predetermined stroke by a driving mechanism (not shown) in a predetermined cycle, whereby the beam 42 also performs similar periodic operations. Do.

  A holding jig 43 for holding the object to be heat-treated 51 in contact with only the edge of the object to be heat-treated 51 is mounted near the tip of the beam 42. When the object to be heat-treated 51 is a solar battery cell, as described above, the electrode material mainly composed of aluminum is also printed on the back surface of the substrate, and immediately after passing through the firing region 19, In some cases, the inside of the aluminum particles having high reactivity in the electrode material may be in a molten state, and when it is in direct contact with the room temperature beam 42 outside the furnace, the heat-treated object 51 is discolored at the contact portion or the performance is increased. There is a risk of lowering. For this reason, it is desirable to use the holding jig 43 as described above and limit the contact of the transport mechanism to the heat-treated object only to the edge of the heat-treated object 51 on which no electrode material is printed.

  In the drying region 9, a required number of linear heaters 1 are arranged in a direction orthogonal to the conveying direction, and the temperature is controlled using the thermocouple 4 so as to obtain a desired temperature condition. In order to improve the heat retaining property of the furnace, the insulating material 2 is covered except for the entrance / exit of the input side transport mechanism. Organic components and the like in the electrode material generated during drying are exhausted from the exhaust pipe 3 using a gas such as air introduced from the air supply pipe 5.

  A necessary number of linear heaters 11 are arranged in the firing region 19 in parallel with the transport direction, and the temperature is controlled using a thermocouple 14 so as to obtain a desired temperature condition. In order to improve the heat retaining property of the furnace, the insulating material 12 is covered except for the entrance / exit of the carry-out side transport mechanism. Organic components and the like in the electrode material generated during firing are exhausted from the exhaust pipe 13 using a gas such as air introduced from the air supply pipe 15.

  In the heat treatment furnace having such a configuration, first, when the object to be heat-treated 51 is charged, as shown in FIG. 1, the loading-side transfer mechanism on the furnace inlet side is in a state where the entire beam 22 is completely out of the furnace. In this state, the object to be heat-treated 51 is placed on the holding jig 23 attached to the beam 22. At this time, the carry-out side transport mechanism on the outlet side of the furnace is also in a state where the beam 32 is completely out of the furnace. In the present invention, “at the time of charging” means that the object to be heat-treated 51 is placed on the holding jig 23 of the feeding-side transport mechanism (the object to be heat-treated is directly placed on the beam 22 without using the holding jig 23). In this case, it is assumed that the time point when it is placed on the beam 22).

  Next, the beam 22 ascends and moves forward (moves in the direction of the furnace outlet), the workpiece 51 is placed in the furnace, and, as shown in FIG. 2, is transferred from the input side transport mechanism to the unload side transport mechanism. It conveys to the terminal part of the dry area 9 which is a position. At the same time, the beam 32 of the carry-out side transport mechanism moves backward (moves in the direction of the furnace entrance), and stops in a state where the tip portion reaches below the tip portion of the beam 22.

  Subsequently, as shown in a partially enlarged view in FIG. 4, the beam 22 descends, and the workpiece 51 is mounted on the beam 32 from the holding jig 23 mounted on the beam 22 in the descending process. Is transferred onto the holding jig 33, and the transfer from the loading side transport mechanism to the unloading side transport mechanism is completed. In the example of FIG. 4, the number of the beam 22 of the carry-out side transport mechanism is one and the number of the beam 32 of the carry-out side transport mechanism is two. In general, this is the processing temperature for firing rather than drying. As the processing temperature increases, the closer the distance between the object to be heat-treated and the beam, the more uneven the processing temperature of the object to be heat-treated and the non-uniform product characteristics. The arrangement is such that the beam 32 for transporting the heat-treated product is arranged farther from the object to be heat-treated 51. In addition, since one beam 22 descends between the two beams 32 of the carry-out side transport mechanism in this way, delivery can be performed without interference between the beam 22 and the beam 32.

  After the delivery is completed in this way, the beam 22 moves backward, and at the same time, the beam 32 moves forward. As shown in FIG. 3, both the beams 22 and 23 are completely out of the furnace again. Finally, as shown in a partially enlarged view in FIG. 5, the beam 42 of the take-out mechanism rises, and in the course of the rise, the object to be heat-treated 51 is moved from above the holding jig 33 attached to the beam 32. Is transferred onto the holding jig 43 attached to the transfer mechanism, and transferred from the carry-out side transfer mechanism to the take-out mechanism. In the example of FIG. 5, the beam 42 of the take-out mechanism is one like the beam 22 of the carry-out side transfer mechanism, and this one beam 42 rises between the two beams 32 of the carry-out side transfer mechanism. By doing so, the beam 42 and the beam 32 can be delivered without interference.

  As described above, in the heat treatment furnace of the present invention, the conveyance mechanism for conveying the object to be heat-treated is divided into two, and the cantilever structure is used for each conveyance mechanism, so that the object to be heat-treated is placed and moved. Since the entire conveying unit, that is, the entire beam can be taken out of the furnace, if the material to be heat-treated breaks on the beam inside the furnace, the operation of the furnace is not stopped or a short time is required. Debris can be easily removed from the beam outside the furnace simply by stopping. Further, since a beam having a smaller heat capacity than that of the mesh belt is used as the transport mechanism, energy consumption is low, rapid heating and rapid cooling are easy, and an ideal heat treatment state of the object to be heat treated can be easily obtained.

  The basic transfer operation in the heat treatment furnace of the present invention is as described above. However, when drying and firing are performed continuously, the time for performing the drying treatment and the time for performing the firing are usually different. is there. In order to cope with this, in the present invention, each transport mechanism is configured so that the cycle time of one operation of the input side transport mechanism and the carry-out side transport mechanism is an integral multiple of the cycle time of the other operation. It is preferable to adjust the cycle time of operation.

  For example, when the drying time is longer than the firing time, the cycle time of the input-side transport mechanism is set to n times (n; an integer) the cycle time of the output-side transport mechanism, and the input-side transport mechanism is operating for one cycle. If the carry-out side transport mechanism operates n times as many cycles, it is possible to select appropriate values for the drying time and the baking time. Further, if both the transport mechanisms are started simultaneously with the positional relationship as shown in FIG. 1 as the origin, the workpiece to be heat-treated between the transport mechanisms can be reliably delivered, and no delivery error occurs. On the other hand, when the drying time is shorter than the firing time, for example, when the drying time is 1 / n times the firing time, the cycle time of the carry-out side transport mechanism is set to n times the cycle time of the input side transport mechanism. A holding jig so that the input-side transport mechanism operates n times as long as the side-side transport mechanism operates for one cycle, and n workpieces are mounted on the beam of the transport-side transport mechanism. And the carry-out side transfer mechanism may start the transfer operation in the firing region when n heat-treated objects are placed on the beam of the carry-out side transfer mechanism.

  Of course, the loading-side transport mechanism and the unloading-side transport mechanism may operate in the same cycle time, and the unloading-side transport mechanism is operated quickly only during the firing of the object to be heat treated. A waiting time may be provided so that the beam of the input side transport mechanism stops and waits until the next heat-treated object is transported to the delivery position in a state where the tip of the beam has returned to the delivery position.

  In the heat treatment furnace of the present invention, as shown in FIG. 4 and the like, a holding jig 33 for holding the object to be heat-treated 51 in contact with the beam 32 of the carry-out side transport mechanism only in contact with the edge of the object to be heat-treated 51 is provided. When mounting, it is preferable that the width a of the portion of the holding jig 33 that contacts the workpiece 51 is 2 mm or less. As described above, when the workpiece 51 is held by the holding jig 33, if the width a of the contact portion between the two is too large, the maximum temperature reached at the contact portion during firing is lower than that in other portions. Become.

  As a result, for example, when the object to be heat-treated 51 is a solar battery cell, the cell conversion efficiency is lowered at the contact portion where the maximum temperature reached is low. As a result of investigating the relationship between the width a of the contact portion and the cell conversion efficiency in the contact portion, the present inventors have found that if the width a of the contact portion is 2 mm or less, the maximum of the contact portion and other parts. It was found that the difference in temperature reached could be kept small, and the cell conversion efficiency was almost uniform over the entire cell surface.

  FIG. 6 is a schematic explanatory view showing an example of the in-furnace structure of the firing region in a cross section orthogonal to the transport direction. In the heat treatment furnace of the present invention, as shown in this figure, it is preferable to provide the heater 11 as a heating means at a position above the workpiece 51. As described above, in the heat treatment furnace of the present invention, when a crack of the heat treatment object occurs on the beam of the transport mechanism, the debris remaining on the beam can be easily removed by taking the beam out of the furnace. There are also pieces that fall from the beam in the furnace without staying on top.

  Therefore, if the heater is provided at a position below the object to be heat-treated, fragments of the object to be heat-treated dropped from the beam may be placed on the heater. In addition, even if cracking of the object to be heat-treated does not occur, for example, when the object to be heat-treated is a solar battery cell, the electrode material or the like peeled off from the substrate due to friction or the like may fall and fall on the heater. Yes. In these cases, there is a possibility that the efficiency of the heater for substantially heating the inside of the furnace is lowered or the heater wire is disconnected. Furthermore, in the case where a glass tube is used as the outer tube of the heater, when the electrode material falls and adheres to the glass tube as described above, the reaction between the glass and the electrode material proceeds instantaneously at a high temperature. In some cases, the heater breaks down and the furnace must be shut down for several hours to replace the heater.

  If a heater is provided at a position above the object to be heat treated, such trouble can be avoided. In a conventional heat treatment furnace for firing solar cells, heaters are provided at both the upper and lower positions of the solar cells, which are the objects to be heat treated, and the front and back surfaces of the solar cells are entirely exposed by the radiation of the heaters. It was common to heat and ensure temperature uniformity on the front and back. However, as a result of investigations by the present inventors, it has been found that even when a heater is provided only at a position above the solar battery cell, temperature uniformity on the front and back sides can be ensured without problems.

  This is because the heater's exothermic light is multiple-reflected by the furnace wall according to Huygens's principle, and the front and back of the solar cells are uniformly heated by radiation, and the heat absorbed by the furnace wall is the atmosphere near the furnace wall. This is because the temperature uniformity of the solar cells is ensured by the effect of warming the gas and increasing the convection to sufficiently contribute to the rise in the furnace temperature and the temperature of the solar cells.

  Further, as shown in FIG. 6, when the heater 11 is provided at a position above the object to be heat-treated 51, a furnace is used so that the heater 11 is not easily contaminated by the organic vapor or combustion gas 53 generated from the object to be heat-treated 51. It is preferable to provide the heater 11 at a position that does not overlap with the passage region of the object to be heat-treated 51 when viewed from directly above. Further, a rectifying plate 17 extending downward from the furnace ceiling portion is provided at a position between the heater 11 and the passage region of the object to be heat-treated 51 when viewed from directly above the furnace, and an air supply port 16 is provided above the heater 11. The exhaust port 13 is preferably provided above the passage region of the object to be heat-treated 51.

  By doing so, the gas such as air introduced into the furnace through the air supply port 16 is heated by the heater 11, then flows from the lower end of the rectifying plate 17 to the passage region of the object to be heat-treated 51, A flow of an atmosphere is created in which the organic vapor and combustion gas 53 generated from the heat-treated product 51 rise and are discharged from the exhaust port 13 to the outside of the furnace, and are generated by the organic vapor and combustion gas 53 generated from the heat-treated material 51. Contamination of the heater 11 can be more effectively prevented.

  In the heat treatment furnace of the present invention, the height L from the inner bottom surface of the furnace to the transfer surface satisfies L ≧ 1.3 × D in relation to the maximum dimension D of the object to be heat treated 51. Is preferred. Here, the “maximum dimension D of the object to be heat treated” refers to the dimension of the largest (longest) portion of the object to be heat treated, for example, the long side when the object to be heat treated is rectangular, and the diameter when it is circular. Equivalent to. In addition, the “transport surface” means the lower surface (bottom surface) of the beam, and when the beam moves in the vertical direction, it means the lower surface of the beam when the beam is in the most lowered state. To do.

  When the height L from the inner bottom surface of the furnace to the transfer surface and the maximum dimension D of the workpiece 51 satisfy the above relationship, the workpiece 51 falls from the beam 32 as shown in FIG. Even if it is randomly deposited on the bottom of the furnace, the height does not reach the conveying surface if it is at the level of several hundred sheets. Therefore, a situation in which the operation is suddenly stopped due to the transfer being hindered by the dropped heat-treated object 51 is less likely to occur, and planned production can be performed.

  In the heat treatment furnace of the present invention, the type and shape of the heater used for the heating means are not particularly limited, and a suitable one can be appropriately selected according to the use of the furnace. Moreover, in the said embodiment, although the thing which integrated the drying area | region and the baking area | region was shown as a form of a furnace, the heat processing furnace aiming at any one of drying and baking may be sufficient. The material to be heat-treated in the heat-treating furnace according to the present invention is not particularly limited, but it can be particularly suitably used for heat-treating relatively small and flat products such as solar cells. .

  The solar battery cell of the present invention is manufactured by heat treatment in the heat treatment furnace of the present invention described above, and by using a heat treatment furnace using a beam having a small heat capacity as a transport mechanism, rapid heating and Quick cooling becomes easy and it is possible to realize a more ideal heat treatment state, so compared to solar cells manufactured in a conventional heat treatment furnace using a mesh belt with a large heat capacity as a transport mechanism. Good characteristics (power generation capacity, etc.) can be expected. In particular, as described above, in the case of manufacturing in a heat treatment furnace using a holding jig such that the width of the portion contacting the edge of the solar battery cell is 2 mm or less, the cell conversion efficiency at the contact portion is reduced. There is almost no deterioration, and almost uniform conversion efficiency can be realized on the entire cell surface.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used as a heat treatment furnace for performing heat treatment of a solar battery cell or the like and a solar battery cell having good characteristics.

It is the schematic explanatory drawing which showed the example of embodiment of the heat processing furnace which concerns on this invention with the cross section along a conveyance direction. It is the schematic explanatory drawing which showed the example of embodiment of the heat processing furnace which concerns on this invention with the cross section along a conveyance direction. It is the schematic explanatory drawing which showed the example of embodiment of the heat processing furnace which concerns on this invention with the cross section along a conveyance direction. It is the schematic explanatory drawing which expanded and showed the state at the time of delivery to the carrying-out side conveyance mechanism from a loading side conveyance mechanism. It is the schematic explanatory drawing which expanded and showed the state at the time of delivery from the carrying-out side conveyance mechanism to the taking-out mechanism. It is the schematic explanatory drawing which showed the example of the in-furnace structure of a baking area | region with the cross section orthogonal to a conveyance direction.

Explanation of symbols

1: heater, 2: heat insulating material, 3: exhaust pipe, 4: thermocouple, 5: air supply pipe, 9: drying region, 10 :, 11: heater, 12: heat insulating material, 13: exhaust pipe, 14: thermocouple , 15: air supply pipe, 16: air supply pipe, 17: current plate, 19: firing region, 21: beam support, 22: beam, 23: holding jig, 24: support roller, 31: beam support, 32: Beam: 33: holding jig, 34: support roller, 41: beam support, 42: beam, 43: holding jig, 51: object to be heat treated, 53: organic vapor or combustion gas.

Claims (10)

A heat treatment furnace for performing a predetermined heat treatment on the heat treatment object while conveying the heat treatment object,
As a transport mechanism for transporting the material to be heat treated, the material to be heat treated is placed in a furnace and transported to a predetermined position in the furnace, and the material to be transported from the input side transport mechanism at the predetermined position. A carry-out side conveyance mechanism that receives the heat-treated product and conveys the heat-treated product from the predetermined position to the outside of the furnace. The object to be heat-treated is conveyed by a beam, and the whole of the beam of the input-side transfer mechanism and the unloading-side transfer mechanism is before the heat-treated object is put into the furnace and after being taken out of the furnace. A heat treatment furnace that is completely out of the furnace.   From the entrance side to the exit side of the furnace, a drying region for drying the heat-treated material and a firing region for firing the heat-treated material are sequentially provided, and the heat-treated material is conveyed in the drying region. 2. The heat treatment furnace according to claim 1, wherein the heat treatment furnace is provided by the input side transfer mechanism, and the heat treatment object is transferred by the carry-out side transfer mechanism in the firing region. The heat treatment furnace according to claim 1, further comprising a support roller that contacts the lower side of the beam of the input side transport mechanism to support the beam. The heat processing furnace as described in any one of Claims 1-3 which provided the support roller which contacts the lower side of the beam of the said carrying-out side conveyance mechanism and supports the said beam. A holding jig is attached to the beam of the carry-out side transport mechanism so as to hold only the edge of the object to be heat-treated and hold the object to be heat-treated. The heat treatment furnace according to any one of claims 1 to 4 , wherein the width of the contacting portion is 2 mm or less. The heat treatment furnace according to any one of claims 1 to 5 , wherein a cycle time of one operation of the input side transfer mechanism and the carry-out side transfer mechanism is an integral multiple of a cycle time of the other operation. A heater is provided as a heating means in the furnace, and the heater is located above the object to be heat-treated and does not overlap with the passage region of the object to be heat-treated when viewed from directly above the furnace. The heat treatment furnace as described in any one of Claims 1-6 provided in. In the firing region, a rectifying plate extending downward from the furnace ceiling portion is provided at a position between the heater and the passage region of the heat-treated material when viewed from directly above the furnace, and an air supply is provided above the heater. The heat treatment furnace according to claim 7 , wherein an opening is provided and an exhaust port is provided above a region through which the heat-treated object passes. Height L from the inner bottom surface of the furnace to the conveying surface, wherein the relationship between the maximum dimension D of the heat-treated, to any one of claims 1-8 satisfies the L ≧ 1.3 × D The heat treatment furnace described. Solar cells produced using the heat treatment furnace according to any one of claims 1-9.

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