JP2010278225A - Photoelectric conversion device, method of manufacturing the same, manufacturing apparatus, and diaphram material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate forming the wiring with a high aspect ratio on a surface of a photoelectric conversion device. <P>SOLUTION: A diaphram material A1 having a photo-setting resin is discharged from a first discharge part 52 moving to scan a surface of a substrate W, and is irradiated with an UV light from backward to be set. A wiring material is discharged from a second discharge part 54 moving further backward. When this takes place, as diaphrams B1 and B2 are formed in a peripheral part at a discharge position of the wiring material, the wiring material does not spread in a plane direction, and a wiring CW with the high aspect ratio can be formed. The diaphrams B1 and B2 are sealed along with the wiring by using the material having a refractive index equal to a sealer, or are put in a semi-curing state by light irradiation and volatilized by heat treatment after the wiring is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion device, a method and apparatus for manufacturing the photoelectric conversion device, and a partition wall material suitable for manufacturing the device.

  For example, in a manufacturing technique of a photoelectric conversion device that receives light and generates an electromotive force, such as a solar cell, it is necessary to arrange a current collecting electrode or wiring on a light receiving surface of a substrate. As a technique for forming such a wiring, there are a technique for depositing a metal as a wiring material on the surface of a substrate, a technique for printing a coating liquid containing a conductive material by screen printing or an inkjet method, and the like. The wiring for the photoelectric conversion device is preferably one that shields incident light as much as possible and does not reduce the photoelectric conversion efficiency, and has a low electrical resistance. A high height ratio is desirable. However, since the above technique generally forms a thin-film wiring, a high aspect ratio cannot always be obtained.

  On the other hand, in the field of manufacturing technologies such as organic EL elements and plasma display panels, there is also used a method of forming elements in a predetermined pattern by pouring a liquid element material between partition walls formed on a substrate such as a glass substrate. It is conceivable to adopt such a technique to cope with the above problem. For example, in the technique described in Patent Document 1, a grid line (wiring) material having fluidity with respect to a substrate surface and a sacrificial material discharged so as to sandwich both sides thereof are coextruded, and then the substrate is heat treated to sacrifice the material. By evaporating, grid lines with a high aspect ratio are obtained.

JP 2008-118150 A (FIGS. 1 and 5)

  Similar to the wiring, the partition wall material used for the photoelectric conversion device is required not to shield the incident light on the light receiving surface. However, Patent Document 1 describes plastics, ceramics, oils, cellulose, latex, polymethyl methacrylate, combinations thereof, and the like as sacrificial materials. These materials include those that do not dissipate due to heat treatment or the like, and the residue may block incident light. In addition, although Patent Document 1 does not specifically describe the heat treatment conditions, it is assumed that heat treatment for a high temperature or a long time is necessary to completely dissipate these sacrificial materials, and a material that cannot withstand such heat treatment is used. It cannot be applied to the production of the photoelectric conversion device used.

  Thus, it can be said that in the field of manufacturing technology of photoelectric conversion devices, a technique for forming wiring with a high aspect ratio has not yet been established.

  This invention is made | formed in view of the said subject, and it aims at providing the technique which can form easily the wiring of a high aspect ratio on the surface of a photoelectric conversion device.

  A first aspect of a method for manufacturing a photoelectric conversion device according to the present invention is a method for manufacturing a photoelectric conversion device in which a wiring having a predetermined wiring pattern is formed on a substrate surface having a photoelectric conversion layer, and achieves the above object. Therefore, a liquid partition material having photocurability is applied to a position corresponding to the peripheral portion of the wiring pattern on the substrate surface, and the applied partition wall material is irradiated with light to be cured, whereby the wiring A partition formation step of forming a partition at a position corresponding to the peripheral edge of the pattern, and a wiring formation step of forming a wiring corresponding to the wiring pattern by applying a liquid wiring material to the substrate surface sandwiched between the partitions And a sealing step of laminating an optically transparent sealing material on the substrate surface on which the partition walls and the wirings are formed, the partition walls being optically transparent and having a refractive index of It is characterized by the same or substantially the same as the refractive index of the encapsulant.

  In the invention configured as described above, since the wiring is formed by applying the wiring material to the region sandwiched between the partitions formed by photocuring, the ratio between the line width and the height, that is, the wiring having a high aspect ratio is formed. Can be formed. Further, since the partition walls are optically transparent and have the same or substantially the same refractive index as that of the sealing material, both of them can be regarded as optically integrated, and the partition walls do not block incident light. Therefore, it is not necessary to dissipate the partition walls after forming the wiring. For this reason, it is possible to apply this invention also when using the board | substrate which is not suitable for a high temperature process, for example, the board | substrate which contains an amorphous silicon layer, and the board | substrate which uses a resin film as a base material.

  Here, the sealing material may be an ethylene / vinyl acetate copolymer resin, and the partition material may be substantially composed of an ethylene-based resin, an acrylate monomer, and a photopolymerization initiator. The partition wall formed by photopolymerization of an ethylene-based resin and an acrylate monomer and the sealing material made of an ethylene / vinyl acetate copolymer resin have similar optical characteristics, and therefore can be suitably applied to the present invention. Is possible. Here, the term “substantially” means that addition of materials other than those described above is allowed within a range in which the optical characteristics of the partition walls are not changed.

  In particular, the acrylate monomer may be, for example, a trifunctional or higher polyfunctional acrylate, and the ethylene resin may be, for example, an ethylene / vinyl acetate copolymer resin or an ethylene / acrylate copolymer resin. These materials have good adhesion to the encapsulant made of ethylene / vinyl acetate copolymer resin and become a relatively strong structure by photocuring, reducing the stress applied to the wiring during the sealing process and damaging the wiring Can be prevented.

  The photoelectric conversion device according to the present invention is an optically transparent substrate formed on a substrate having a photoelectric conversion layer and on the substrate surface at a position corresponding to a peripheral portion of the wiring pattern corresponding to a predetermined wiring pattern. A partition wall, a wiring corresponding to the wiring pattern formed by applying a liquid wiring material to the substrate surface sandwiched between the partition walls, and optically covering the substrate surface on which the partition wall and the wiring are formed. A transparent sealing material, and the refractive indexes of the partition wall and the sealing material are the same or substantially the same.

  In the invention configured as described above, a high aspect ratio wiring can be realized by using the partition wall, and the partition wall has a refractive index equivalent to that of the sealing material, so that the partition wall does not shield incident light. From the point, high photoelectric conversion efficiency can be obtained.

  A second aspect of the method for manufacturing a photoelectric conversion device according to the present invention is a method for manufacturing a photoelectric conversion device in which a wiring having a predetermined wiring pattern is formed on a substrate surface having a photoelectric conversion layer, and the above object is achieved. In order to achieve this, the liquid partition wall material is applied to a position corresponding to the peripheral portion of the wiring pattern on the substrate surface, and the applied partition wall material is irradiated with light to be cured in a semi-cured state. A partition formation step of forming a partition at a position corresponding to the peripheral edge of the wiring pattern, and a wiring formation for forming a wiring corresponding to the wiring pattern by applying a liquid wiring material to the substrate surface sandwiched between the partitions And a heat treatment step of dissipating the partition by heat-treating the substrate on which the wiring is formed.

  The partition wall for pouring the liquid wiring material does not necessarily need to be strong, and the shape may be maintained to such an extent that the wiring material can be prevented from flowing out. From this point of view, it is not necessary to be completely cured by light, and it may be in a semi-cured state. Here, the “semi-cured state” refers to a state in which the partition walls are not completely solid, only the surface is solidified and the inside remains liquid, or the surface or the whole is solidified in a gel state. . On the other hand, the semi-cured state as described above has an advantage that the molecules constituting the partition walls are not so strongly bonded, and thus can be easily thermally decomposed by a heat treatment in a subsequent process. Therefore, it is possible to form a high aspect ratio wiring by a method in which the partition walls are dissipated and leave only the wiring. At this time, the temperature during the heat treatment can be lowered and the processing time can be shortened, so that the substrate by heat Can minimize damage.

  A third aspect of the method for manufacturing a photoelectric conversion device according to the present invention is a method for manufacturing a photoelectric conversion device in which a wiring having a predetermined wiring pattern is formed on a substrate surface having a photoelectric conversion layer. In order to achieve this, the wiring pattern is formed by applying a photocurable liquid partition material at a position corresponding to the peripheral portion of the wiring pattern on the substrate surface and irradiating the applied partition material with light. A partition forming step of forming a partition at a position corresponding to the peripheral edge of the wiring, and a wiring forming step of forming a wiring corresponding to the wiring pattern by applying a liquid wiring material to the substrate surface sandwiched between the partitions. And a heat treatment step for dissipating the partition by heat-treating the substrate on which the wiring is formed, and the partition material is an acrylate monomer and a photopolymerization initiator. It is characterized by using a liquid mainly composed of.

  In the invention thus configured, the main component of the partition wall material is an acrylate monomer. Unlike polymers in which a large number of molecules are bonded in advance, a large amount of light irradiation is required to crosslink and completely cure the acrylate monomer by light irradiation. In other words, a strong cross-linked structure is not completed by light irradiation for a short time. Therefore, it is easy to thermally decompose. By utilizing this fact, a high-aspect ratio wiring can be easily formed in the same manner as in the other aspects of the present invention by forming a semi-cured partition wall made of an acrylate monomer and applying a wiring material. In addition, the subsequent heat treatment process does not require high temperature and long time heating.

  Here, the acrylate monomer may be, for example, an acrylate or methacrylate having 3 or less functional groups. In a material containing many functional groups, a partition wall having a higher strength than necessary is formed due to complex cross-linking between molecules, and thermal decomposition is difficult. According to the experiments by the inventors of the present application, good results were obtained when an acrylate or methacrylate having 3 or less functional groups was used.

Further, for example, the partition formation step may be performed in an atmosphere containing oxygen, and the light irradiation amount to the partition material may be 5 to 200 mJ / cm ² . Since oxygen has an effect of inhibiting the curing of the partition wall material, it is possible to suppress excessive curing by performing light irradiation in an atmosphere containing oxygen. Moreover, if there is little light irradiation amount, it will not harden | cure at all. On the other hand, if there is too much light irradiation amount, hardening will advance too much. According to the experiments by the inventors of the present application, the appropriate amount of light irradiation was about 5 to 200 mJ / cm ² .

Moreover, the manufacturing apparatus of the photoelectric conversion device concerning this invention discharges the liquid partition material which has photocurability which has an acrylic ester monomer as a main component with respect to the substrate surface in order to achieve the said objective. And a light irradiator for forming a partition by irradiating the partition wall material discharged onto the substrate surface with light at an irradiation dose of 5 to 200 mJ / cm ² and curing it in a semi-cured state in an atmosphere containing oxygen And a second discharge unit that discharges a liquid wiring material to the substrate surface sandwiched between the partition walls, the first discharge unit, the light irradiation unit, and the second discharge unit, and the substrate surface And a moving mechanism that moves relative to each other.

  In the invention thus configured, a high aspect ratio wiring can be formed by applying the wiring material between the partition walls formed by curing the partition wall material in a semi-cured state. Further, by arbitrarily moving the first discharge part for discharging the partition wall material, the light irradiation part for irradiating and curing the predetermined amount of light to the partition wall material, and the second discharge part for discharging the wiring material, it is arbitrarily moved. A high aspect ratio wiring having a pattern can be easily formed. The partition material used is mainly composed of acrylate monomer, which acts as a partition in a semi-cured state, and is easily thermally decomposed by subsequent heat treatment, so that the partition remains after the device is completed. Does not block light.

  The partition wall material according to the present invention is a partition wall material applied to the substrate surface to form the partition wall, and in order to achieve the above object, an acrylic ester monomer having 3 or less functional groups, a light It is characterized by being a liquid comprising a polymerization initiator. Since such a partition wall material becomes a semi-cured state by light irradiation, it effectively functions as a partition wall when a coating liquid of an element material such as a wiring material is applied in a predetermined pattern on a substrate. Furthermore, since it is in a semi-cured state, it is easily pyrolyzed, and the heat treatment temperature can be lowered or the heat treatment time can be shortened.

  According to the method and apparatus for manufacturing a photoelectric conversion device according to the present invention, a photoelectric conversion device having a high aspect ratio wiring can be manufactured. In addition, the photoelectric conversion device according to the present invention has high photoelectric conversion efficiency because there is no shielding of incident light by the partition walls, and low power loss due to the low resistance of the wiring.

It is a figure which shows schematic structure of the manufacturing apparatus of the photoelectric conversion device which can apply this invention suitably. It is an enlarged view which shows the structure of a head part in detail. It is a figure which shows typically the mode of discharge of the partition material and wiring material from a head part. It is a flowchart which shows the manufacture procedure of the photoelectric conversion device of 1st Embodiment. It is a figure which shows typically the manufacturing process of the photoelectric conversion device of 1st Embodiment. It is a figure which shows the example of the experimental result of the partition material in 1st Embodiment. It is a flowchart which shows the manufacture procedure of the photoelectric conversion device of 2nd Embodiment. It is a figure which shows typically the manufacturing process of the photoelectric conversion device of this embodiment. It is a figure which shows the example of the experimental result of the partition material in 2nd Embodiment.

<Configuration of manufacturing equipment>
FIG. 1 is a diagram showing a schematic configuration of a photoelectric conversion device manufacturing apparatus to which the present invention can be suitably applied. This manufacturing apparatus 1 is an apparatus that forms a conductive wiring on a substrate W such as a single crystal silicon wafer having a photoelectric conversion layer formed on the surface thereof, and manufactures a photoelectric conversion device used as a solar cell, for example. is there. The apparatus 1 can be suitably used for an application in which a collecting electrode is formed on a light incident surface of a photoelectric conversion device, for example. This device is a partial modification of the device configuration described in Japanese Patent No. 3868298 previously disclosed by the applicant of the present application, and the basic configuration and operation are the same as those described in the same publication. is doing.

  In the manufacturing apparatus 1, the stage moving mechanism 2 is provided on the base 11, and the stage 3 holding the substrate W can be moved in the XY plane shown in FIG. 1 by the stage moving mechanism 2. A frame 12 is fixed to the base 11 so as to straddle the stage 3, and the head unit 5 is attached to the frame 12.

  The stage moving mechanism 2 includes an X direction moving mechanism 21 that moves the stage 3 in the X direction from the lower stage, a Y direction moving mechanism 22 that moves the stage 3 in the Y direction, and a θ rotation mechanism 23 that rotates about an axis that faces the Z direction. Have. The X-direction moving mechanism 21 has a structure in which a ball screw 212 is connected to a motor 211 and a nut 213 fixed to the Y-direction moving mechanism 22 is attached to the ball screw 212. When the guide rail 214 is fixed above the ball screw 212 and the motor 211 rotates, the Y-direction moving mechanism 22 moves smoothly along the guide rail 214 in the X direction along with the nut 213.

  The Y-direction moving mechanism 22 also has a motor 221, a ball screw mechanism, and a guide rail 224. When the motor 221 rotates, the θ-rotation mechanism 23 moves in the Y direction along the guide rail 224 by the ball screw mechanism. The θ rotation mechanism 23 rotates the stage 3 about the axis facing the Z direction by the motor 231. With the above configuration, the relative movement direction and orientation of the head unit 5 with respect to the substrate W can be changed.

  The head unit 5 includes a first discharge unit 52 that discharges liquid partition wall material onto the substrate W on the lower surface of the base 51, and a light irradiation unit 53 that irradiates UV light (ultraviolet rays) toward the substrate W. A supply pipe 522 having a check valve 521 is attached to the first discharge part 52. The supply pipe 522 is branched, and one is connected to the pump 523 and the other is connected to the tank 525 storing the partition wall material via the control valve 524. The light irradiation unit 53 is connected to a light source unit 532 that generates ultraviolet rays via an optical fiber 531.

  In addition, on the opposite side of the head unit 5 from the first discharge unit 52 with the light irradiation unit 531 in between, a second discharge unit 54 that discharges a liquid wiring material is provided. A supply pipe 542 having a check valve 541 is attached to the second discharge part 54. The supply pipe 542 is branched, one is connected to the pump 543, and the other is connected to the tank 545 for storing the wiring material via the control valve 544. The composition of the partition wall material and the wiring material will be described later.

  The motors of the stage moving mechanism 2, the pumps 523 and 544, the control valves 524 and 544, and the light source unit 532 are connected to the control unit 6, and the configuration thereof is controlled by the control unit 6, whereby the substrate W by the manufacturing apparatus 1. An upper wiring pattern is formed.

  FIG. 2 is an enlarged view showing the configuration of the head portion in more detail. More specifically, FIG. 2 (a) is a view showing the shape of the vicinity of the first and second discharge portion tips when the head portion 5 is viewed from the side, and FIG. 2 (b) is a view of the head portion 5 viewed from below. It is a figure. As shown in FIG. 2A, the inside of the first discharge part 52 is a cylindrical cavity 52a, and the lower end opens obliquely rightward in the drawing to form a first discharge port 52b. The liquid partition material transported from the tank 525 via the supply pipe 522 is discharged toward the substrate W from the first discharge port 52 b at the lower end of the first discharge unit 52.

  Similarly, the inside of the second discharge part 54 is a cylindrical cavity 54a, and the lower end is opened obliquely rightward in the drawing to form a second discharge port 54b. The liquid wiring material transported from the tank 545 via the supply pipe 542 is discharged toward the substrate W from the first discharge port 54 b at the lower end of the second discharge unit 54. The lower end of the second discharge unit 54 is located above (+ Z direction) than the lower end of the first discharge unit 52.

  Further, a lens 533 is provided at the tip of the light irradiation unit 53, and the UV light from the light source unit 532 is configured to be condensed on the partition wall material discharged from the first discharge unit 52 onto the substrate W. ing.

  As shown in FIG. 2B, a plurality of first discharge ports 52b and second discharge ports 54b are arranged in the Y direction. More specifically, the second discharge ports 54 b are provided at a plurality of locations (three locations in this example) at equal intervals on the lower surface of the second discharge portion 54. On the other hand, two first discharge ports 52b are provided in pairs on the lower surface of the first discharge portion 52 so as to sandwich the position where the second discharge ports 54b are disposed in the Y direction. In this example, three pairs (six locations) of first discharge ports 52b are provided corresponding to the three second discharge ports 54b. The lens 533 at the lower end of the light irradiation unit 53 is formed in an oval shape so as to cover all the positions where the first ejection ports 52b are arranged in the Y direction.

  Note that the number of the first and second discharge ports is not limited to this. The material of the first discharge part 52 and the second discharge part 54 is not particularly limited, but for example, silicon or zirconia crystals are used from the viewpoint that contaminants are not mixed into the discharge liquid and fine processing can be performed. be able to.

  FIG. 3 is a diagram schematically showing how the partition wall material and the wiring material are discharged from the head portion. More specifically, FIG. 3A is a side view of the state in which the partition wall material and the wiring material are discharged from the head portion 5. FIG. 3B is a view of the same viewed from obliquely above. In FIG. 3B, the light irradiation unit 53 is not shown in order to make it easier to see the state of discharge from the first discharge unit 52. Hereinafter, the basic operation of wiring formation by the manufacturing apparatus 1 will be described with reference to FIGS. 1 to 3.

  The partition material is discharged from the first discharge unit 52 by the check valve 521, the pump 523, and the control valve 524 shown in FIG. First, the pump 523 performs a suction operation with the control valve 524 being opened under the control of the control unit 6. At this time, since the check valve 521 prevents the backflow of the wiring material, the wiring material is drawn from the tank 525 to the pump 523. Next, the control valve 524 is closed under the control of the control unit 6, and the pump 523 performs an extrusion operation. Thereby, the partition wall material A1 is continuously discharged from each of the plurality of first discharge ports 52b of the first discharge section 52.

  When the partition wall material is discharged, the control unit 6 controls driving of the motors of the stage moving mechanism 2 so that the surface of the substrate W moves in the (+ X) direction below the head unit 5. . In other words, the head unit 5 moves in the (−X) direction while relatively scanning the surface of the substrate W. Thereby, the partition wall material is applied to the surface of the substrate W in a streak shape along the X direction. At this time, the partition wall material A1 is discharged from the first discharge port 52b toward the rear in the scanning movement direction, and the discharged liquid is prevented from staying in the vicinity of the first discharge port 52b.

  On the rear side (the right side in FIG. 3A) of the first discharge unit 52 in the relative movement direction of the head unit 5 with respect to the substrate W, the UV light L is irradiated from the light irradiation unit 53 to the discharged partition wall material A1. The As will be described later, the partition wall material A1 is mainly composed of a resin material having photocurability, and a crosslinking reaction occurs upon irradiation with the UV light L, and solidification starts. As a result, as shown in FIG. 3B, on the substrate W, a pair of parallel barrier ribs B1 formed by solidifying the two strips of barrier rib material A1 discharged from the pair of first discharge ports 52b, respectively. , B2, and a groove T surrounded by the partition walls B1, B2 and the surface of the substrate W is formed.

  Further, in the relative movement direction of the head unit 5 with respect to the substrate W, a second discharge unit 54 having a second discharge port 54b for discharging the wiring material A2 is provided behind the light irradiation unit 53 (on the right side in FIG. 3A). Is provided. The second discharge port 54b moves in parallel with the first discharge port 52b, and as shown in FIG. 2B, the first discharge port 52b sandwiches the arrangement position of the second discharge port 54b in the Y direction. Is provided. For this reason, the partition walls B1 and B2 are formed on both sides of the discharge position of the wiring material A2 from the second discharge port 54b on the substrate W.

  The wiring material A2 is a conductive paste having a silver filler and a vehicle (a mixture of resin, some organic solvent, thickening material, etc.), and if it is simply applied to a flat substrate surface, it will flow and spread in the plane direction. It is difficult to form a wiring having a high aspect ratio (ratio of the height to the wiring width). In a photoelectric conversion device, since shielding of incident light by wiring causes a decrease in photoelectric conversion efficiency, the wiring width is desirably as small as possible (typically about 50 μm). On the other hand, in order to suppress the loss due to the electrical resistance of the wiring, it is necessary to increase the cross-sectional area of the wiring, and a wiring having a high aspect ratio is desired.

  In this manufacturing apparatus 1, since the wiring material A2 can be poured into the groove portion T sandwiched between the partition walls B1 and B2 formed of the photocurable resin as described above on the surface of the substrate W, FIG. As shown, since the applied wiring material does not spread in the surface direction and the thickness can be maintained, the wiring CW having a high aspect ratio can be obtained by volatilizing the solvent component of the wiring material A1.

  That is, in this apparatus 1, the partition material A1 and the wiring material A2 are discharged from the first discharge port 52b and the second discharge port 54b, respectively, and the substrate W is moved in the X direction while irradiating the light irradiation unit 53 with UV light. By causing the head unit 5 to scan and move with respect to the surface of the substrate W, the number of wires CW (three in this example) parallel to each other and corresponding to the number of the second ejection ports 54b can be formed. In addition, by performing this operation by changing the relative positions of the head unit 5 and the substrate W in the Y direction, a large number of wirings CW can be formed on the surface of the substrate W. Furthermore, by controlling the scanning movement path of the head unit 5, it is possible to form the wiring CW having an arbitrary pattern on the surface of the substrate W.

  Here, the partitions B1 and B2 can also be a factor for blocking incident light. In the following, two embodiments of the present invention in which a photoelectric conversion device is formed using the above-described apparatus 1, and a photoelectric conversion device that does not block incident light by the partition walls B1 and B2 can be formed. explain.

<First Embodiment>
In the first embodiment of the method for manufacturing a photoelectric conversion device according to the present invention, the partition walls B1 and B2 are made of a material having optical characteristics similar to those of a sealing material provided on the substrate surface in order to protect the substrate after wiring formation. Form. Specifically, the partition walls B1 and B2 are formed of a material that is optically transparent and has the same or substantially the same refractive index as the sealing material. By doing so, it can be considered that the partition walls B1 and B2 do not exist optically.

  FIG. 4 is a flowchart showing a manufacturing procedure of the photoelectric conversion device of this embodiment. Moreover, FIG. 5 is a figure which shows typically the manufacturing process of the photoelectric conversion device of this embodiment. First, an unprocessed substrate W is carried into the apparatus 1 (step S101). At this time, the substrate W is placed on the stage 3 with the photoelectric conversion layer on which the wiring is to be formed facing upward. Then, the apparatus 1 is operated as described above, and the partition wall material A1 is applied to the surface of the substrate W and cured by light irradiation to form the partition walls B1 and B2 (step S102; partition wall forming step). Further, the wiring material A2 is applied to the groove T surrounded by the partition wall thus formed (step S103; wiring formation step). In the manufacturing apparatus 1 described above, steps S102 and S103 can be simultaneously performed by scanning the head unit 5.

  Thereafter, the substrate W coated with the wiring material is unloaded from the apparatus 1 (step S104), is dried by a known drying processing apparatus (step S105), and the solvent contained in the wiring material A2 is volatilized to obtain the wiring CW. . The substrate W coated with the wiring material may be dried by being left in the coating apparatus 1 for a while.

  At this stage, as shown in FIG. 5A, the surface of the substrate W is in a state in which the wiring CW sandwiched between the partition walls B1 and B2 is formed. Subsequently, in order to protect the wiring and the substrate surface, a sealing material is laminated on the substrate surface (step S106; sealing process). Specifically, as shown in FIG. 5 (b), a sheet-like sealing material S is placed on the substrate W, and this is heated and pressure-pressed, as shown in FIG. 5 (c). The sealing material S is brought into close contact with the upper surface of the substrate W so that the surface of the substrate W is completely covered with the sealing material. As the sealing material S, EVA (ethylene / vinyl acetate copolymer) resin can be suitably used from the viewpoints of high transparency, adhesion to the surface of the substrate S, and durability.

  Thereby, as shown in FIG. 5 (d), the surface of the substrate W is sealed with the sealing material S together with the partition walls B1, B2 and the wiring CW, and the photoelectric conversion device D1 is completed. At this time, if the refractive index of the partition walls B1 and B2 is substantially the same as that of the sealing material S, the sealing material S and the partition walls B1 and B2 can be regarded as an integral unit. That is, it is equivalent to sealing the surface of the substrate W on which only the wiring CW without a partition wall is formed with the sealing material S.

  Examples of the partition wall material suitable for the first embodiment are shown below. According to the experiments by the present inventors, when EVA resin is used as the sealing material, when the partition wall material A1 made of an acrylate monomer, an ethylene resin, and a photopolymerization initiator is used, the wiring material A2 is poured. It has been found that a partition wall that functions well as a barrier rib and that has substantially the same refractive index as that of the sealing material and does not block incident light can be formed after the device is completed. In addition, if it is a grade which does not reduce transparency, you may contain some materials other than this. Further, from the viewpoint of application workability, the viscosity of the partition wall material is suitably about 200 m to 20000 cPa · s.

  Among these, as the acrylic ester monomer, for example, trimethylolpropane triacrylate, isocyanuric acid EO-modified triacrylate, pentaerythritol tri (or tetra) acrylate, ditrimethylolpropane triacrylate, dipentaerythritol penta (or hexa) acrylate, etc. A trifunctional or higher polyfunctional acrylate is desirable.

  Examples of the ethylene resin include copolymer resins of ethylene and vinyl esters such as vinyl acetate and vinyl propionate, copolymer resins of ethylene and unsaturated carboxylic acid esters such as methyl acrylate and ethyl acrylate, A copolymer resin of ethylene and an unsaturated carboxylic acid such as acrylic acid or methacrylic acid or an ionomer thereof, a copolymer resin of ethylene and an α-olefin, or a mixture of two or more of these can be used.

  Examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one-1-hydroxy-cyclohexyl-phenyl-ketone and bis (2,4,6 trimethylbenzoyl) -phenylphosphine. Fin oxide and the like can be used.

  FIG. 6 is a diagram showing an example of an experimental result of the partition wall material in the first embodiment. The first discharge port 52b has a width (Y direction) of 20 μm and a height (X direction) of 60 μm, and the composition of the partition wall material A1 is changed, and the obtained partition wall width (W) and height (H), The suitability for press working (press temperature 200 ° C.) and the transparency after lamination were evaluated. The materials used in this experiment are as follows.

(1) Acrylic acid ester monomer Aronix M-305: manufactured by Toagosei Co., Ltd., pentaerythritol acrylic acid ester (special polyfunctional acrylate),
(2) Ethylene resin Evaflex EV260: manufactured by Mitsui DuPont Polychemical Co., Ltd., ethylene vinyl acetate copolymer resin,
Elvalloy EMA1609AC: manufactured by Mitsui DuPont Polychemical Co., Ltd., ethylene methyl acrylate copolymer resin,
High Milan 1652: Mitomer DuPont Polychemical Co., Ltd., ethylene methacrylic acid copolymer ionomer,
Nukurel NO908C: manufactured by Mitsui DuPont Polychemical Co., Ltd., ethylene methacrylic acid copolymer resin,
(3) Photopolymerization initiator IRGACURE 184: Ciba Specialty Chemicals, 1,2α-hydroxydialkylphenone (alkylphenone photopolymerization initiator),
IRGACURE 819: manufactured by Ciba Specialty Chemicals, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (phosphine oxide photopolymerization initiator).

  In any composition, good partition walls can be obtained, and by applying a conductive paste as the wiring material A2 to the grooves between the partition walls formed in this way, for example, wiring CW having a line width and height of about 50 μm. Could be formed. In addition, although the above-mentioned acrylate monomer M-305 is a polyfunctional acrylate, when a polypropylene glycol diacrylate was used instead of this as a bifunctional acrylate, the softening point of the partition wall was low, and it did not endure press processing. .

  As described above, in this embodiment, a partition wall is formed at a peripheral portion of a position where a wiring on the substrate W is to be formed, and a wiring material is applied to a groove portion sandwiched between the partition walls, thereby reducing the line width and reducing the thickness. A certain high aspect ratio wiring can be formed. This partition is left even when the device is completed. In this case, since the partition wall is formed of a transparent material having substantially the same refractive index as that of the sealing material, in the device after sealing with the sealing material, the partition wall does not shield incident light and is high. Photoelectric conversion efficiency can be obtained.

<Second Embodiment>
Next, 2nd Embodiment of the manufacturing method of the photoelectric conversion device concerning this invention is described. In this embodiment, as in the above-described Patent Document 1, after the partition wall is formed and the wiring material is applied, the partition wall is dissipated by heat treatment to leave only the wiring. Patent Document 1 did not disclose the partition material in detail, but this embodiment proposes a specific material that functions well as a partition when a wiring material is applied and that can be easily dissipated by heat treatment. .

  FIG. 7 is a flowchart showing the manufacturing procedure of the photoelectric conversion device of this embodiment. Moreover, FIG. 8 is a figure which shows typically the manufacturing process of the photoelectric conversion device of this embodiment. As in the first embodiment, first, an unprocessed substrate W is carried into the apparatus 1 (step S201). At this time, the substrate W is placed on the stage 3 with the photoelectric conversion layer on which the wiring is to be formed facing upward. Then, the apparatus 1 is operated as described above, and the partition wall material A1 is applied to the surface of the substrate W and cured by light irradiation to form the partition walls B1 and B2 (step S202; partition wall forming step). Further, the wiring material A2 is applied to the groove T surrounded by the partition walls formed in this way (step S203; wiring formation step). In the manufacturing apparatus 1 described above, steps S202 and S203 can be simultaneously performed by scanning the head unit 5. Thereafter, the substrate W coated with the wiring material waste contaminated material is unloaded from the manufacturing apparatus 1 (step S204).

  The processing performed using the manufacturing apparatus 1 in FIG. 1 is the same as that in the first embodiment except for the composition of the partition wall material. That is, steps S201 to S204 in FIG. 7 correspond to steps S101 to S104 in the first embodiment (FIG. 4). The state of the substrate at this point is as shown in FIG. 8A, which is the same as that shown in FIG.

  Thereafter, in this embodiment, by baking the substrate, the partition walls B1 and B2 are volatilized and dissipated to leave only the wiring CW (step S205, FIG. 8B; heat treatment step). Although the firing temperature is as high as 700 ° C., the firing time is as short as 15 seconds, so there is almost no damage to the substrate W. The short baking time is due to the composition of the partition wall material, which will be described later.

  Next, as in the first embodiment, the device is completed by sealing the surface of the substrate W with a sealing material (step S206, FIGS. 8C to 8D), but in this embodiment, sealing is performed. The process is not essential and may be omitted. In this embodiment, since the partition walls are dissipated before sealing, only the wiring CW is sealed together with the surface of the substrate W. Therefore, as shown in FIG. 8E, the completed device D2 does not have a partition wall and does not shield incident light.

  Next, the composition of the partition material will be described. In this embodiment, by adjusting the partition wall material, a semi-cured state in which the partition after photocuring is not completely solidified, that is, only the surface is solidified and the inside is in a liquid state, or the whole is solidified in a gel state. Like that. In this way, when the wiring material is applied, the semi-cured partition wall prevents the wiring material from flowing out and enables a high aspect ratio wiring to be formed, while the partition wall can be easily dissipated by a short time or low temperature heat treatment. .

  According to the experiments by the present inventors, the partition wall material having such a function includes a liquid mainly composed of an acrylate ester monomer and a photopolymerization initiator, in particular, the number of functional groups as the acrylate ester monomer. Those using 3 or less can be suitably used. Acrylic acid ester monomers with a small number of functional groups do not undergo a high degree of cross-linking when exposed to light for a short period of time. It becomes. This is convenient as a partition wall to be dissipated later. This is because the partition wall in this case only needs to have a shape retention enough to prevent the outflow of the liquid wiring material, so there is no problem even in a semi-cured state, and since the bond between molecules is weak, it is highly volatile and easily This is because it can be dissipated.

  Moreover, the viscosity of the partition wall material is desirably about 200 m to 20000 cPa · s, and in order to adjust the viscosity, an appropriate amount of a polymer having high thermal decomposability such as methyl cellulose and PMMA (polymethyl methacrylate) may be added in addition to the above. These polymers have the function of maintaining the cross-sectional shape of the partition walls as a thickener, and the cured product formed by photocuring has a matrix structure in which a liquid resin is wrapped, thereby preventing bumping during firing. There is also an effect to prevent.

  Among these, acrylate monomers include acrylate monomers such as monofunctional acrylates such as phenol EO modified acrylate, nonylphenol EO modified acrylate, 2-ethylhexyl EO modified acrylate, tricyclodecane dimethylol diacrylate, polypropylene glycol diacrylate, Bifunctional acrylates such as polyethylene glycol diacrylate, trifunctional acrylates such as trimethylolpropane triacrylate, trimethylolpropane PO-modified triacrylate, and the like can be used.

  Further, methacrylate monomers such as ethyl methacrylate, n-butyl methacrylate, butoxydiethylene glycol methacrylate, 2-hydroxyethyl methacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate and the like may be used.

  Examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one-1-hydroxy-cyclohexyl-phenyl-ketone and bis (2,4,6 trimethylbenzoyl) -phenylphosphine. Fin oxide and the like can be used.

  In this type of photocurable resin, oxygen generally acts as a factor that inhibits curing. For this reason, it is desirable to perform application | coating and light irradiation in the atmosphere containing oxygen, for example, air | atmosphere. By doing so, it is possible to delay the curing of the partition wall material and to easily maintain the partition wall in a semi-cured state.

  FIG. 9 is a diagram showing an example of an experimental result of the partition wall material in the second embodiment. The first discharge port 52b has a width (Y direction) of 60 μm and a height (X direction) of 150 μm, and the composition of the partition wall material A1 is changed to change the viscosity of the partition wall material, the obtained partition wall width (W) and the height. (H), thermal degradability (treatment temperature 700 ° C.) was evaluated. The materials used in this experiment are as follows.

(1) Acrylic ester monomer Light ester 9EG: manufactured by Toagosei Co., Ltd., polyethylene glycol # 400 dimethacrylate (bifunctional methacrylate),
Aronix M-225: manufactured by Toa Gosei Co., Ltd., polypropylene glycol diacrylate (bifunctional acrylate),
Aronix M-321: manufactured by Toa Gosei Co., Ltd., propylene oxide modified trimethylolpropane triacrylate (trifunctional acrylate),
Aronix M-305: manufactured by Toa Gosei Co., Ltd., pentaerythritol acrylic ester (special polyfunctional acrylate),
(2) Polymer Etocel N-7: Dow Chemical Company, ethyl cellulose,
Dianal BR-105: Mitsubishi Rayon Co., Ltd. acrylic resin,
(3) Photopolymerization initiator IRGACURE 184: manufactured by Ciba Specialty Chemicals, 1,2α-hydroxydialkylphenone (alkylphenone photopolymerization initiator),
IRGACURE 819: bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (phosphine oxide photopolymerization initiator).

  Among these, sample No. whose main component is polyfunctional acrylate. No. 4 had poor thermal decomposability, and a residue was observed on the substrate surface after the heat treatment (indicated by “x” in FIG. 9). Sample No. with low viscosity No. 1 has a very high thermal decomposability (indicated by “」 ”), but the partition wall is wide and low because of its low viscosity. Sample No. Nos. 2, 5, and 6 had good thermal decomposability (indicated by “◯” marks) and sufficient partition wall height. Sample No. In No. 3, the shape of the partition wall is good, but the thermal decomposability is slightly inferior (indicated by “Δ” mark).

  Sample No. In each sample except 4, there was almost no residue on the surface of the substrate W after the heat treatment. Further, since the wettability of the wiring material is lowered when at least the surface of the partition wall is cured, the applied wiring material can be retained in the groove T, and mixing of the partition wall material and the wiring material also occurs. Absent. In each sample, wiring having a line width and height of about 50 μm could be formed by applying a wiring material between the formed partition walls.

In addition, 5 to 200 mJ / cm ² was appropriate as the light irradiation amount to these materials, that is, the integrated value (integrated light amount) of the irradiated light amount. If the amount of light irradiation is larger than this, curing proceeds too much and the thermal decomposability deteriorates, and if it is less than this, it hardly cures and does not function as a partition.

  As described above, in this embodiment, a partition is formed by applying a light curable resin as a partition material to the substrate surface and irradiating with light, and after applying a wiring material to a groove portion sandwiched between the partitions, firing is performed. By volatilizing the partition walls, a high aspect ratio wiring can be formed. At this time, the partition wall material is easily volatilized at the time of firing by not completely curing the partition wall material but keeping it in a semi-cured state. For this reason, the partition walls can be dissipated at a low baking temperature or in a short baking time. For this reason, it is possible to apply the above-described wiring formation technology to a device using a material that cannot withstand heat treatment at a long time or at a high temperature.

<Others>
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, the composition of the partition wall material shown in each of the above embodiments is a partial example, and the present invention is not limited to this, and other combinations of the materials listed above may be used. Good.

  In each of the above embodiments, the wiring is formed only on one surface of the substrate W. However, the present invention can be applied to the case where the wiring is formed on both surfaces of the substrate W.

  In each of the above embodiments, a photoelectric conversion device as a solar cell is manufactured by forming wiring on a silicon substrate having a photoelectric conversion layer, but the substrate is not limited to silicon. For example, the present invention can also be applied when wiring is formed on a thin film solar cell formed on a glass substrate. Moreover, since the manufacturing method of 1st Embodiment does not require the heat processing at high temperature essentially, it can be applied also to manufacture of the photoelectric conversion device which uses a resin film etc. as a board | substrate, for example. The present invention can also be applied to photoelectric conversion devices other than solar cells.

  The present invention is particularly suitably applied to a field where a thin line width, that is, a high aspect ratio wiring is required, such as a light receiving surface of a solar cell, and shielding of incident light by a partition wall may be a problem. can do.

1 Photoelectric conversion device manufacturing apparatus 2 Stage moving mechanism (moving mechanism)
21 X-direction moving mechanism 22 Y-direction moving mechanism 23 θ rotation mechanism 52 First discharge portion 53 Light irradiation portion 54 Second discharge portion A1 Partition material A2 Wiring material B1, B2 Partition CW Wiring W Substrate

Claims (11)

In a method for manufacturing a photoelectric conversion device for forming a wiring having a predetermined wiring pattern on a substrate surface having a photoelectric conversion layer,
A liquid partition material having photocurability is applied to a position corresponding to the peripheral portion of the wiring pattern on the surface of the substrate, and the applied partition material is irradiated with light to be cured. A partition forming step of forming a partition at a position corresponding to the peripheral edge;
Forming a wiring corresponding to the wiring pattern by applying a liquid wiring material to the substrate surface sandwiched between the partition walls; and
A sealing step of laminating an optically transparent sealing material on the substrate surface on which the partition and the wiring are formed,
The method for manufacturing a photoelectric conversion device, wherein the partition wall is optically transparent, and the refractive index thereof is the same as or substantially the same as the refractive index of the sealing material.   The method for producing a photoelectric conversion device according to claim 1, wherein the sealing material is an ethylene / vinyl acetate copolymer resin, and the partition material substantially includes an ethylene-based resin, an acrylate monomer, and a photopolymerization initiator. .   The method for producing a photoelectric conversion device according to claim 2, wherein the acrylic ester monomer is a trifunctional or higher polyfunctional acrylate.   The method for producing a photoelectric conversion device according to claim 2 or 3, wherein the ethylene resin is an ethylene / vinyl acetate copolymer resin or an ethylene / acrylate copolymer resin. A substrate having a photoelectric conversion layer;
An optically transparent partition wall formed on the substrate surface at a position corresponding to the peripheral edge of the wiring pattern corresponding to a predetermined wiring pattern;
A wiring corresponding to the wiring pattern, in which a liquid wiring material is applied to the substrate surface sandwiched between the partition walls;
An optically transparent sealing material covering the substrate surface on which the partition and the wiring are formed,
The photoelectric conversion device, wherein the partition walls and the sealing material have the same or substantially the same refractive index. In a method for manufacturing a photoelectric conversion device for forming a wiring having a predetermined wiring pattern on a substrate surface having a photoelectric conversion layer,
A liquid partition wall material is applied to a position corresponding to the peripheral edge of the wiring pattern on the substrate surface, and the applied partition wall material is irradiated with light to be cured in a semi-cured state, whereby the peripheral edge of the wiring pattern A partition forming step of forming a partition at a position corresponding to the portion;
Forming a wiring corresponding to the wiring pattern by applying a liquid wiring material to the substrate surface sandwiched between the partition walls; and
And a heat treatment step of dissipating the partition by heat-treating the substrate on which the wiring is formed. In a method for manufacturing a photoelectric conversion device for forming a wiring having a predetermined wiring pattern on a substrate surface having a photoelectric conversion layer,
A liquid partition material having photocurability is applied to a position corresponding to the peripheral portion of the wiring pattern on the surface of the substrate, and light is applied to the applied partition material, so that the peripheral portion of the wiring pattern is applied. A partition formation step of forming a partition at a corresponding position;
Forming a wiring corresponding to the wiring pattern by applying a liquid wiring material to the substrate surface sandwiched between the partition walls; and
A heat treatment step of dissipating the partition by heat-treating the substrate on which the wiring is formed,
A method for producing a photoelectric conversion device, wherein a liquid mainly composed of an acrylate monomer and a photopolymerization initiator is used as the partition wall material.   The method for producing a photoelectric conversion device according to claim 7, wherein the acrylate monomer is an acrylate or methacrylate having 3 or less functional groups. The method for manufacturing a photoelectric conversion device according to claim 7 or 8, wherein the partition wall forming step is performed in an atmosphere containing oxygen, and the light irradiation amount to the partition wall material is set to 5 to 200 mJ / cm ² . A first discharge unit that discharges a liquid partition material having photocurability mainly composed of an acrylate monomer to the substrate surface;
A light irradiating unit that forms a partition by irradiating the partition wall material discharged onto the substrate surface with light at an irradiation amount of 5 to 200 mJ / cm ² and curing it in a semi-cured state in an atmosphere containing oxygen;
A second discharge part for discharging a liquid wiring material to the substrate surface sandwiched between the partition walls;
An apparatus for manufacturing a photoelectric conversion device, comprising: a moving mechanism that integrally moves the first ejection unit, the light irradiation unit, and the second ejection unit relative to a substrate surface. A partition material applied to the substrate surface to form a partition,
A partition material characterized by being a liquid comprising an acrylic ester monomer having 3 or less functional groups and a photopolymerization initiator.

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