JP2011129641A - Wiring forming method and wiring forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of forming fine wiring with a controlled aspect ratio with high throughput as wiring forming technique for forming wiring on a principal surface of a substrate. <P>SOLUTION: A guide clamp 33 having clamped a wire CW is passed over a substrate W mounted on a stage 10, and the wire WC is extended along the principal surface of the substrate by being pressed with an end clamp 13. An excessive wire is cut with a cutter 14, and conductive paste P is applied orthogonally to the wire CW, so that the wire is fixed. Then the substrate is baked to fuse low-melting-point metal on a surface of the wire CW, so that the wire is fixed to the substrate W and the conductive paste P is baked. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wiring forming method and a wiring forming apparatus for forming a wiring on a main surface of a substrate, and more particularly to a technique for forming a fine wiring.

  In the technical field of forming a predetermined wiring on a substrate, particularly when forming a wiring with a fine line width of about several tens of μm, a coating liquid containing a wiring material is applied to the substrate by an inkjet method or a screen printing method. A technique for forming such fine wiring is known. For example, in the technique described in Patent Document 1, a current collecting electrode is formed by applying a conductive paste to the surface of a semiconductor substrate for a solar cell element by a screen printing method.

Japanese Unexamined Patent Publication No. 2007-062079 (for example, FIG. 1 and FIG. 3)

  In the technical field where such wiring formation technology is expected to be applied, the ratio of the thickness of the wiring to the width of the wiring (aspect ratio) is particularly appropriate, as in the case of the current collecting electrode in the photoelectric conversion element such as the solar cell described above. In some cases, controlled wiring is required. However, in the wiring forming method by coating as described above, the line width increases when a large amount of coating solution is applied at one time. Therefore, in order to obtain a wiring with a fine line width and a thickness, a small amount of coating work is required. There is a problem that it is theoretically difficult to form wiring with a controlled aspect ratio at a high throughput.

  The present invention has been made in view of the above problems, and provides a technique capable of forming a fine and controlled aspect ratio wiring with a high throughput in a wiring forming technique for forming a wiring on a main surface of a substrate. is there.

  In order to achieve the above object, the wiring forming method according to the present invention includes a disposing step of disposing a thin wire-shaped wiring material having a surface formed of a conductive material along a main surface of the substrate, and the conductive material. And an adhering step of adhering to the main surface of the substrate by melting with heat. In the invention configured as described above, a desired wiring pattern can be formed on the substrate by arranging the thin wire material along the main surface of the substrate. The formed wiring pattern can be fixed to the main surface of the substrate by melting the conductive material on the surface of the wiring material by heat. Therefore, the aspect ratio of the wiring formed on the substrate can be controlled by the cross-sectional shape of the wiring material, and the wiring formation throughput can be made higher than that of the conventional technique in which the thickness is obtained by recoating. .

  In the present invention, the wiring material may be, for example, a core wire covered with the conductive material having a melting point lower than that of the core wire. In this way, by heating to a temperature not exceeding the melting point of the core wire, the conductive material is brought into close contact with the main surface of the substrate while maintaining the cross-sectional shape of the wiring by the core wire, and the aspect ratio is high and the electrical characteristics are excellent. Wiring can be formed. As such a core wire material, for example, a metal wire, a carbon fiber wire, a glass fiber wire or the like can be used.

  In particular, when the core wire is conductive, such as a metal wire, the core wire and the conductive material on the surface take on the conductivity as a whole, so that the electrical resistance of the wiring can be reduced. it can. As such a metal material, gold, copper, aluminum, stainless steel, or the like can be suitably used. A metal can also be used as the conductive material. As a result, the electrical resistance of the wiring can be kept low. As such a metal material, a metal having a low melting point is particularly preferable, and for example, tin, a solder alloy, indium or the like can be suitably used.

  Moreover, after the arrangement step and before the fixing step, a coating step of applying a coating liquid to the substrate main surface and fixing the wiring material to the substrate main surface may be further provided. By doing so, it is possible to prevent the wiring material disposed on the main surface of the substrate from being deformed or changing its position before being fixed. In addition, for example, when a conductive paste having conductivity after solidification is used as the coating solution, fine wiring formed by the wiring material and wiring having a large cross-sectional area formed by the conductive paste are mixed. A wiring pattern can be formed.

  This method is particularly effective when the current collecting electrode is formed on the solar cell substrate. That is, in the disposing process, a large number of wiring materials are disposed on the main surface of the substrate substantially in parallel, and in the applying process, for example, a conductive paste is applied as a coating solution so as to cross these, and the surface of the wiring material is fixed in the fixing process. The conductive material is melted and fixed to the main surface of the substrate. While the wiring material fixed to the substrate becomes a finger electrode with a high aspect ratio, the conductive paste has a function of temporarily fixing the wiring material before fixing and as a bus electrode having a large cross-sectional area intersecting with the finger electrode after fixing. Function. Thus, by applying this wiring forming method, it is possible to manufacture a solar cell with excellent electrical characteristics with a small number of man-hours.

  Further, as a method of heating the wiring material in the fixing step, for example, a method of heating the wiring material from the outside (referred to as “indirect heating method” in this specification) can be considered. As a specific aspect of this method, for example, a heating means such as a heater is disposed in the vicinity of the wiring material disposed on the main surface of the substrate, or the substrate on which the wiring material is disposed is baked in a baking furnace. it can. Further, as another method, a method of energizing the wiring material to generate heat (referred to as “direct heating method” in this specification) can be considered, and as a specific aspect thereof, the wiring material is stretched along the main surface of the substrate. An electrode is brought into contact with both ends of the wiring material, and a current can flow from the electrode to the wiring material.

  In order to achieve the above object, the wiring forming apparatus according to the present invention includes a substrate holding means for holding a substrate, a supply means for supplying a thin wire-shaped wiring material whose surface is formed of a conductive material, and the substrate. Arrangement means for arranging the wiring material along the main surface of the substrate held by the holding means, and heating means for heating and melting the conductive material to fix it to the main surface of the substrate. It is characterized by. In the invention configured in this way, as in the invention of the wiring forming method described above, the wiring can be formed with high throughput while the aspect ratio of the wiring formed on the substrate is controlled by the cross-sectional shape of the wiring material. it can.

  In this case, there may be further provided application means for applying the coating liquid to the substrate main surface on which the wiring material is arranged by the arrangement means and fixing the wiring material to the substrate main surface. By doing so, the wiring material before fixing can be fixed. Moreover, it becomes possible to form various wiring patterns by using a coating liquid having conductivity after solidification.

  According to the wiring forming method and the wiring forming apparatus according to the present invention, the fine wire-shaped wiring material is disposed along the main surface of the substrate, and the conductive material on the surface of the wiring material is melted by heat and fixed to the main surface of the substrate. Therefore, the aspect ratio of the wiring formed on the substrate can be controlled by the cross-sectional shape of the wiring material, and the wiring can be formed with high throughput.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the main structures of 1st Embodiment of the wiring formation apparatus concerning this invention. It is the figure which looked at the wiring formation apparatus of FIG. 1 from diagonally upward. It is a flowchart which shows the wiring formation process in 1st Embodiment. It is a figure which shows typically operation | movement of each part in wiring formation processing. It is a figure which shows the state of the board | substrate after paste application | coating. It is a figure which shows the cross-section of the wire in this embodiment. It is a figure which shows the example of the cross-sectional shape of the wire after a baking process. It is a figure which shows 2nd Embodiment of the wiring formation apparatus concerning this invention. It is a flowchart which shows the wiring formation process in 2nd Embodiment.

  FIG. 1 is a side view showing a main configuration of a first embodiment of a wiring forming apparatus according to the present invention. FIG. 2 is a view of the wiring forming apparatus of FIG. 1 as viewed obliquely from above. This wiring forming apparatus 1 forms conductive electrode wiring on one main surface Wa of a substrate W such as a single crystal silicon wafer having a photoelectric conversion layer formed on the surface thereof, for example, a photoelectric used as a solar cell. An apparatus for manufacturing a conversion device. That is, this apparatus 1 can be used suitably for the use of forming electrode wiring on the light incident surface of a photoelectric conversion device, for example. In this specification, orthogonal coordinate axes X, Y and Z axes are defined as shown in FIGS. 1 and 2, respectively. According to this definition, the XY plane represents a horizontal plane, and the Z direction means upward in the vertical direction.

  In the wiring forming apparatus 1, a stage 10 having an upper surface substantially the same size as the substrate W and on which the substrate W can be placed is provided. A heating plate 11, a pair of scanning nozzles 12, 12, and a pair of end clamps 13, 13 are provided above the stage 10.

  The heating plate 11 is for heating the substrate W placed on the stage 10, and includes a heater 111 and is disposed so that its lower surface faces the upper surface 10 a of the stage 10. Further, the scanning nozzles 12 and 12 are configured to discharge the conductive paste supplied from the paste supply unit 2 from the discharge port provided at the lower end and to be integrally movable in the Y direction. Further, the end clamps 13 and 13 are plate-like members that are respectively provided above both ends of the substrate W in the X direction and whose length in the Y direction is longer than the length of the substrate W in the Y direction. The end clamps 13 and 13 can freely move up and down. When the end clamps 13 and 13 are lowered, the lower surface 13 a abuts against the peripheral edge of the substrate W and presses the substrate W against the stage 10.

  In addition, a pair of cutters 14 and 14 whose upper end portions are sharp blades are provided at both ends of the stage 10 in the X direction. The cutters 14 and 14 are movable up and down, and the upper ends of the cutters 14 and 14 are lifted to the upper side of the upper surface Wa of the substrate W on the stage 10 as necessary, and are stretched on the substrate W as will be described later. Cut the wire.

  A wire supply unit 3 is provided on the side of the stage 10. The wire supply unit 3 includes a wire delivery block 31, a guide nozzle 32, and a guide clamp 33 for delivering an extremely fine wire CW having a diameter of about 10 to 100 μm. (In this example, 8 sets) are provided. The wire delivery block 31 includes a bobbin 311 around which the wire CW is wound, a support base 312 that rotatably supports the bobbin 311, and an arm 313 that extends from the support base 312 toward the stage 10. The same number of wire delivery blocks 31 as the number of wires to be formed are arranged at equal intervals in the Y direction. The tip of the arm 312 is formed in a ring shape so as to insert the wire CW.

  The guide nozzle 32 includes a main body 321 provided with a guide groove (not shown) for inserting the wire CW on the upper surface, and an arm 322 extending from the main body 321 toward the wire delivery block 31. The same number of guide nozzles 32 as the number of power lines are arranged at equal intervals in the Y direction. The tip of the arm 322 is formed in a ring shape so as to insert the wire CW. The wire CW pulled out from the bobbin 311 passes from the arm 313 on the wire delivery block 31 side through the arm 322 on the guide nozzle 32 side, and its leading end CWa is positioned by the guide nozzle 32 and protrudes near the stage 10.

  The arrangement pitch of the guide nozzles 32 in the Y direction is variable and is set to be the same as the arrangement pitch of the wirings to be formed on the substrate W. Thus, the wire CW is positioned near the stage 10 at a pitch corresponding to the wiring arrangement pitch. On the other hand, the arrangement pitch of the wire delivery block 31 can be changed by transferring the wire between the wire delivery block 31 and the guide nozzle 32 via the arms 313 and 322. It can be arbitrarily set according to the size of the bobbin 311 regardless of the pitch.

  Between the guide nozzle 32 and the stage 10, it extends along the Y direction and can be opened and closed in the vertical direction, and clamps and holds the tip of the wire CW held by the guide nozzle 32 in the closed state. A guide clamp 33 is provided. The guide clamp 33 is movable in the X direction from one end side (right side in FIG. 1) to the other end side (left side in FIG. 1) of the substrate W across the stage 10 in a closed state. Yes. That is, the guide clamp 33 moves horizontally from the upper right to the upper left of the stage 10 in a state where the tips of the plurality of wires CW respectively held by the plurality of guide nozzles 32 are collectively clamped.

  As the guide clamp 33 moves, the wire CW is pulled out from the bobbin 311. Therefore, when the guide clamp 33 is moved to the upper left of the stage 10, the wire CW drawn from each bobbin 311 is stretched in parallel above the substrate W.

  In FIG. 1 and FIG. 2, a dotted arrow attached in the vicinity of each member represents the moving direction of the member. However, in FIG. 1, description of the movement direction of the operation nozzle 12 that moves in the Y direction, that is, the direction perpendicular to the paper surface of FIG. 1 is omitted.

  In addition, the wiring forming apparatus 1 includes a control unit 6 that forms the above-described components and executes a wiring forming process described later, and a driving mechanism 7 for driving the components. The operation of each component of the wiring forming apparatus 1 described above is realized by operating the control unit 6 and the drive mechanism 7.

  Next, the operation of the wiring forming apparatus 1 configured as described above will be described. In the wiring formation process shown below, a plurality of thin and parallel electrodes called finger electrodes and a bus with a large cross-sectional area perpendicular to these finger electrodes are formed on the surface of the substrate W on which a photoelectric conversion layer for solar cells is formed. This is a process for forming a current collecting electrode composed of electrodes called electrodes. This wiring formation process is realized by the control unit 6 executing a control program prepared in advance to operate each part of the apparatus.

  FIG. 3 is a flowchart showing the wiring formation process in the first embodiment. FIG. 4 is a diagram schematically showing the operation of each part in the wiring formation process. In addition, in each small drawing of FIG. 4, while showing the position of each member after execution of the process demonstrated below typically, the moving direction is shown by the broken-line arrow about the member moved at the next process of the said process. Yes.

  First, the wiring forming apparatus 1 is initialized (step S101). The initialization state in this apparatus is a state in which the substrate W is removed from the states shown in FIGS. That is, in the initialization state, the heating plate 11 and the end clamp 13 are retracted above the stage 10 and the cutter 14 is retracted below the stage 10. The guide clamp 33 is located between the stage 10 and the guide nozzle 32 and is open. Further, the scanning nozzle 12 is in a position retracted to the back side in FIG. Further, the leading portion CWa of the wire CW pulled out from the bobbin 311 protrudes from the guide nozzle 32.

  In this state, the substrate W to be processed is loaded from the outside and placed on the stage 10 (step S102). Subsequently, the guide clamp 33 is closed, and the eight wire tip portions CWa protruding from the eight sets of guide nozzles 32 are collectively clamped (step S103, FIG. 4A). Then, with the wire clamped, the guide clamp 33 is passed over the substrate W and moved to the opposite side in the (−X) direction (step S104, FIG. 4B). As a result, the wire CW is stretched over the substrate W. The pitch between the wires is kept constant by the guide nozzle 32, and the eight wires CW are stretched parallel to the upper part of the substrate.

  Next, the end clamps 13 and 13 are lowered and brought into contact with the substrate W, whereby the wire CW is pressed against the end portion of the substrate W to be clamped (step S105, FIG. 4C). As a result, the eight wires CW are arranged in parallel to each other in the X direction along the substrate surface Wa (arrangement step).

  When both ends of the wire CW are clamped on the substrate W by the end clamps 13 in this way, the guide clamp 33 releases the wire clamp, returns to the initial position, and newly clamps the wire protruding from the guide nozzle 32. By clamping the wire before cutting the wire, the next wire can be stretched smoothly. A mechanism for holding the tip of the wire may be separately provided before releasing the guide clamp 33 moved to the left end. Further, another set of guide clamps may be provided, and the guide clamp moved to the left side may be kept at that position and the wire near the guide nozzle 32 may be clamped with another set of guide clamps. .

  Then, the cutter 14 is raised along the end surface of the stage 10, and the wire CW extending from the end surface of the end clamp 13 is cut (step S106). Subsequently, while discharging the conductive paste P from the scanning nozzles 12 and 12, the scanning nozzles 14 and 14 are moved in the (−Y) direction, that is, in FIG. In FIG. 4, the sheet is moved from the back side to the near side (step S107, FIG. 4 (d)).

  FIG. 5 is a diagram showing the state of the substrate after applying the paste. In this figure, the end clamp 13 is not shown. The moving direction (Y direction) of the scanning nozzles 14 and 14 is a direction orthogonal to the stretching direction (X direction) of the wire CW stretched over the substrate. Therefore, the paste P discharged from the scanning nozzles 14 and 14 is applied on the wire CW stretched over the substrate main surface Wa in the vicinity of both ends of the substrate W in the X direction. Thereby, on the board | substrate, the both ends vicinity of the wire CW is temporarily fixed by the paste P, and it will be in the state which does not move (application | coating process). That is, it is possible to release the clamp of the wire at the end of the substrate by the end clamps 13 and 13 (step S108). At this point, the wire CW and the conductive paste P are disposed on the main surface Wa of the substrate corresponding to the desired pattern.

  After retracting the end clamps 13 and 13 upward, instead, the heating plate 11 is lowered to come close to the substrate main surface Wa, and the wire CW and the conductive paste P disposed on the substrate main surface Wa are set in a predetermined manner. The wire CW and the paste P are baked by heating to a temperature (step S109; fixing step).

  The wire CW used in this embodiment has at least the surface thereof made of a conductive material, and is particularly made of a low melting point conductive material. In such a configuration, the conductive material on the surface of the wire is melted by the baking process, and the wire CW is fixed to the substrate W and electrically conducted. By setting the material and baking conditions so that the shape of the wire does not collapse greatly by melting, the wire CW stretched over the substrate W adheres to the substrate W in an almost intact shape, and fine electrode wiring (finger electrodes) Will function as. When the molten conductive material wraps around the gap between the wire and the substrate, the contact area between the two becomes large, and a low electrical resistance is obtained. Further, when the conductive paste P applied to the substrate W is baked by baking, the conductive paste P functions as a bus electrode that is wider and intersects with the finger electrodes.

  That is, by performing the baking process, the wire CW stretched over the substrate W and the applied paste P function as electrodes. Even when an insulating film is formed on the surface of the substrate W, it is possible to break the insulating layer and ensure conduction between the substrate and the electrode (fire-through) by performing the baking process. By carrying out the substrate W on which the electrodes are thus formed from the apparatus 1 (step S110), the wiring formation process is completed.

  FIG. 6 is a view showing a cross-sectional structure of the wire in this embodiment. Moreover, FIG. 7 is a figure which shows the example of the cross-sectional shape of the wire after a baking process. The wire CW used in this embodiment has, for example, the following cross-sectional structure. A wire CW1 illustrated in FIG. 6A is a so-called clad wire in which the surface of a metal core wire 911 is covered with a metal surface layer 912 having a melting point lower than that of the core wire 911. Here, as the core wire 911, a material having excellent conductivity such as gold, silver, copper, aluminum, nickel, brass, and stainless steel is preferable. On the other hand, for the surface layer 912, tin, lead, solder alloy, indium, or the like which is lower than the core wire 911 and has good conductivity can be used. Such a wire CW1 can be obtained, for example, by passing through the core wire 911 while melting the metal to be the electroless plating or the surface layer 912.

  As shown in FIG. 7A, the surface layer 912 is fused to the substrate main surface Wa by the baking process, so that conduction between the wire CW1 and the substrate main surface Wa is ensured. At this time, by performing the baking process at a temperature lower than the melting point of the core wire 911, the cross-sectional shape of the core wire 911 does not change. That is, the cross-sectional shape of the wiring obtained by the baking process is almost similar to the cross-sectional shape of the core wire 911. That is, the cross-sectional shape of the wiring can be controlled by the cross-sectional shape of the core wire 911 and the thickness of the surface layer 912, and a wiring having a desired aspect ratio can be obtained.

  Further, the wire CW2 illustrated in FIG. 6B is entirely formed of a low melting point metal 921 such as tin or a solder alloy. Further, for example, silver, copper, brass, or the like may be used as long as it is possible to perform heating enough to melt the surface in the baking process. Even in such a configuration, by appropriately setting conditions such as temperature and time in the baking process, it is possible to fix the substrate W to the substrate W while maintaining a shape close to the original shape.

  In addition, in the wire CW3 illustrated in FIG. 6C, a thin core wire 931 is covered with a thick surface layer 932. In such a structure, since the electrical conduction is mainly performed by the surface layer 932 having a large cross-sectional area, the core wire 931 does not necessarily need conductivity. In this sense, the core wire 931 may be an insulator as long as it has an action of maintaining an appropriate tensile strength and shape. For example, glass fiber or carbon fiber, a steel wire having low conductivity but high tensile strength, etc. is used. May be. In particular, a material having a low coefficient of thermal expansion is preferable in order to prevent disturbances such as bending of the wiring and floating from the substrate W due to the expansion and contraction of the wire due to heat.

  As shown in FIG. 7B, in the case where the core wire 931 is thin and the surface layer 932 is thick, when the surface layer 932 is melted by baking, so-called sagging occurs, and the cross-sectional shape of the wiring is easily broken to reduce the aspect ratio. Therefore, in this case, management of temperature and time in the baking process is important for maintaining the cross-sectional shape of the wiring.

  In addition, the wire CW4 illustrated in FIG. 6D is obtained by forming the core wire 941 as a stranded wire made of a plurality of strands and covering the surface layer 942 thereon. Also in this case, the core wire 941 may be either a conductive material or an insulating material. With such a configuration, as shown in FIG. 7C, even if the surface layer 942 is melted, the cross-sectional shape of the wiring can be avoided from being greatly collapsed.

  As described above, in this embodiment, in order to form a fine wiring with an appropriately controlled aspect ratio on the substrate W, the wire CW having a surface made of a conductive material having a relatively low melting point is used as the substrate. Wiring is performed by stretching along the main surface Wa and heating this to melt the wire surface and fix the wire to the substrate. According to such a configuration, the aspect ratio of the wiring can be controlled with good controllability depending on the cross-sectional shape of the wire, and the wiring can be formed with a higher throughput than the wiring forming technique by applying the coating liquid. .

  In addition, by applying a paste-like coating liquid to the substrate W on which the wires CW are provided and fixing the wires CW, the wiring pattern formed before the baking process is not broken. The applied paste can also be used as wiring by firing.

  Next, a second embodiment of the wiring forming apparatus according to the present invention will be described. In the first embodiment described above, the conductive material on the surface of the wire by the “indirect heating method” referred to in this specification, in which the heating plate 11 is brought close to the wire CW disposed along the substrate W and the wire CW is heated from the outside. Was melted and fixed to the substrate W. In contrast, in the second embodiment described below, the wire surface is melted and fixed to the substrate W by a “direct heating method” in which the wire CW itself generates heat.

  FIG. 8 is a view showing a second embodiment of the wiring forming apparatus according to the present invention. FIG. 9 is a flowchart showing a wiring formation process in the second embodiment. First, the difference between the operation and the first embodiment will be described. Note that, in the configuration of the wiring forming apparatus according to the second embodiment, portions common to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the wiring forming process according to the first embodiment, the wire CW is stretched over the substrate W placed on the stage 10, clamped by the end clamp, and cut by the cutter 14 (steps S <b> 101 to S <b> 106 in FIG. 3). ) Is exactly the same in the wiring formation process of the second embodiment (steps S201 to S206 in FIG. 9). The subsequent operation is different.

  As shown in FIG. 8A, in the second embodiment, after the wire is cut, the current source 44 is electrically connected between the end clamps 43 and 43 that clamp both ends of the cut wire CW. (Step S207). The end clamp 43 is made of a conductive material. Therefore, a conductive path is formed to return to the current source 44 via the current source 44, one end clamp 43, the wire CW on the substrate main surface Wa, and the other end clamp 44, and current flows through the wire CW. By passing a current set appropriately, the temperature of the wire CW rises due to Joule heat, and the surface melts and adheres to the substrate main surface Wa.

  Therefore, at this time, the wire CW is fixed to the substrate surface and the finger electrode is formed, and the clamp by the end clamp 43 can be released and the substrate W can be carried out (steps S208 and S209). Since it is not necessary to fix the wire by applying the paste, the conductive paste application for forming the bus electrode can be performed by using an application apparatus different from the present apparatus. In addition, the baking process for the wire is unnecessary in principle, but when the baking process is performed for baking the paste, a baking apparatus different from the coating apparatus can be used. Therefore, the wiring forming apparatus of this embodiment does not require a heating plate, a scanning nozzle, a paste supply unit, and a mechanism for driving them. A device configuration common to the first embodiment can be used except that these configurations are unnecessary and a configuration for energizing the wires is required. Of course, the paste application or baking process may also be performed in the apparatus of the second embodiment. In this case, paste application is performed after execution of step S207 of FIG. 9, and baking processing is performed after execution of step S208.

  As described above, when each process of forming a wire, applying a conductive paste, and baking is performed by different apparatuses, the time for which one apparatus is occupied for processing on one substrate is shortened. This contributes to greatly improving the throughput when processing on a plurality of substrates is continuously performed. In addition, depending on the type of wiring to be formed, at least one of paste application and baking may be omitted, which further improves the throughput.

  As in the first embodiment, the aspect ratio of the formed wiring can be controlled by the structure of the wire CW to be used. As the wire CW, a wire having the same structure as that described in the first embodiment can be used.

  Here, in the second embodiment, the handling when energizing the plurality of wires CW arranged on the substrate W will be described. When a plurality of wires are connected in parallel and energized, the wires may break due to current concentration on a specific wire, or other wires may not be heated sufficiently. In order to deal with such a problem, for example, the following can be performed.

  For example, as shown in FIG. 8B, one of the end clamps 43 is electrically separated corresponding to each wire, and a current is supplied to each of the separated end clamps 431 to 438. The sources 441 to 448 may be connected one by one. In this way, since the appropriate current flows through each wire, the above problem does not occur.

  Further, as shown in FIG. 8C, a single voltage source 46 is connected to each of the electrically separated end clamps 431 to 438 via resistors 451 to 458, respectively. Also good. Also in this case, since the current flowing through each wire is limited by the resistors 451 to 458, the above problem can be avoided.

  Further, as shown in FIG. 8D, a single current source 44 is provided for the end clamps 431 to 438 that are electrically separated, and a wire for supplying current is sequentially switched by a switch 47. However, the same effect can be obtained. In these configurations, the other end clamp 43 may be configured to electrically short-circuit a plurality of wires.

  As described above, in the second embodiment of the wiring forming apparatus according to the present invention, heat is generated by passing a current through the wire CW stretched along the substrate main surface Wa, and the surface is melted to be fixed to the substrate. I am doing so. According to such a configuration, it is possible to form fine wiring with a desired aspect ratio with a high throughput as in the case of the apparatus of the first embodiment.

  As described above, in each of the above embodiments, the stage 10 functions as the “substrate holding means” of the present invention. The wire CW corresponds to the “wiring material” of the present invention, and the wire supply unit 3 functions as the “supplying unit” of the present invention. In this embodiment, the guide nozzle 32, the guide clamp 33 and the end clamp 13 (43) function as an “arrangement unit” of the present invention. Further, the heating plate 11 in the first embodiment and the current source 44 in the second embodiment all function as the “heating means” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, eight wirings are formed at equal intervals on the substrate W, but the number of wirings formed and the pitch are not limited to this. Further, for example, a wire supply unit that supplies only one wire may be provided, and a plurality of wirings may be formed in order.

  In the above embodiment, the wiring is formed using the wire having a substantially circular cross-sectional shape, but the cross-sectional shape and aspect ratio of the formed wiring can be arbitrarily controlled by appropriately changing the cross-sectional shape. It is possible.

  In the above embodiment, the conductive material on the surface of the wire is heated and melted by providing a heating plate on the substrate or by passing a current through the wire. For example, the stage on which the substrate is placed is used as a hot plate. The wire may be heated from the stage. Moreover, you may make it perform the baking process after paste application with another apparatus.

  Further, in order to prevent the wires arranged along the substrate from floating especially at the central portion of the substrate, the upper surface of the stage may be provided with a slight curvature so as to protrude upward.

  In the first embodiment, the pair of scanning nozzles 14 and 14 for applying the conductive paste to the substrate W are provided. However, the number of scanning nozzles is not limited to this, and the pattern to be formed is not limited to this. Depending on the situation, one or three or more may be provided.

  In the first embodiment, the wire disposed on the substrate is fixed with a conductive paste, and the conductive paste functions as an electrode after firing. For the purpose of simply fixing the wire, It is not an essential requirement that the paste has conductivity. In that sense, for example, a material that becomes a non-conductive protective film may be applied. Moreover, in the said 2nd Embodiment, although direct current is sent and heated to the wire arrange | positioned at the board | substrate, you may make it send alternating current. In particular, if a high-frequency current is allowed to flow, it is expected that the current concentrates on the surface due to the skin effect, and the temperature of the wire surface is selectively increased.

  Moreover, although the said embodiment applies this invention to the apparatus for manufacturing the solar cell module which has an electrode which made the finger electrode and the bus electrode orthogonal, the application object of this invention is limited to this. However, the present invention can be applied to various uses that require fine wiring formation.

  The present invention can be applied to an apparatus and method for forming fine wiring on a main surface of a substrate, and can be suitably applied particularly when it is necessary to control the aspect ratio of wiring.

3 Wire supply section (supply means)
10 stages (substrate holding means)
11 Heating plate (heating means)
13, 43 End clamp (arrangement means)
32 Guide nozzle (arrangement means)
33 Guide clamp (arrangement means)
44 Current source (heating means)
CW wire (wiring material)
W substrate

Claims (9)

A disposing step of disposing a thin wire-shaped wiring material whose surface is formed of a conductive material along the main surface of the substrate;
A wiring forming method comprising: a fixing step of melting the conductive material by heat and fixing the conductive material to the main surface of the substrate.   The wiring formation method according to claim 1, wherein the wiring material is obtained by coating a core wire with the conductive material having a melting point lower than that of the core wire.   The wiring forming method according to claim 2, wherein the core wire has conductivity.   The wiring forming method according to claim 2, wherein the conductive material is a metal.   5. The coating method according to claim 1, further comprising a coating step of coating a coating liquid on the substrate main surface and fixing the wiring material to the substrate main surface after the arranging step and before the fixing step. Wiring formation method.   6. The wiring forming method according to claim 1, wherein in the fixing step, the wiring material is heated to melt the conductive material.   The wiring forming method according to claim 1, wherein in the fixing step, the conductive material is melted by energizing the wiring material to generate heat. Substrate holding means for holding the substrate;
Supply means for supplying a thin wire-shaped wiring material whose surface is formed of a conductive material;
Disposing means for disposing the wiring material along the main surface of the substrate held by the substrate holding means;
Heating means for heating and melting the conductive material and fixing the conductive material to the main surface of the substrate. The wiring forming apparatus according to claim 8, further comprising a coating unit that applies a coating liquid to the substrate main surface on which the wiring material is disposed by the arranging unit and fixes the wiring material to the substrate main surface.

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