JP5232466B2 - Photovoltaic device - Google Patents

Description

  The present invention has a photovoltaic cell integrated structure in which photovoltaic cell elements having sensitivity to at least a part of light within a range from the infrared region to the visible light region are integrated on one chip, and the photovoltaic cell integrated structure, The present invention relates to a photovoltaic cell device that is converted to electricity and converts light into electricity.

  As a photovoltaic cell, there is a solar cell in which unit power generation elements formed of silicon having sensitivity to visible light and infrared light are connected in series, and a solar cell device having a configuration in which a plurality of solar cells are arranged in an array is proposed. (For example, refer to Patent Documents 1 and 2). In this type of photovoltaic device, individual photovoltaic cells are manufactured, and the photovoltaic cells are individually connected to a mounting substrate such as a printed circuit board by mounting.

  In addition, a photovoltaic device that receives infrared light energy in an invisible infrared wavelength region and generates electricity has also been proposed (see, for example, Patent Document 3).

Patent Publication No. 2824882 JP-A-2005-11869 JP 2006-237543 A

  However, in the type of photovoltaic device in which individual photovoltaic cells are manufactured and the photovoltaic cells are individually mounted and connected to a mounting board such as a printed circuit board, the operation of mounting the individual photovoltaic cells is very difficult. . In addition, since a space for mounting (arrangement space for wire bonding or the like) is required around each photovoltaic cell, mounting a large number of photovoltaic cells in order to obtain a high voltage output reduces the device area. Since it becomes large, there also existed a problem that improvement in productivity and cost reduction were difficult.

  The present invention has been made to solve the above-mentioned problems, and its purpose is easy to manufacture, and when mounting on a mounting board on a printed board or the like, the work is easy. It is an object of the present invention to provide a photovoltaic cell integrated structure that can be easily manufactured and handled, and a photovoltaic device that can improve productivity and reduce costs by using the photovoltaic cell integrated structure.

  The present invention is configured as means for solving the above problems with the following configuration. That is, in the photovoltaic cell integrated structure according to the first aspect of the present invention, a diffusion layer of a different type from the silicon substrate is provided on the surface side of one of the n-type and p-type silicon substrates. A plurality of photovoltaic cell elements are arranged in the direction of the substrate surface of the silicon substrate, and a function of holding the plurality of photovoltaic cell elements is provided on the back side of the plurality of photovoltaic cell elements. An insulating resin base material is provided, and an electrode that conducts to the silicon substrate of each photovoltaic cell element is formed at least in the hole position formed by subjecting the resin base material to a hole drilling process by chemical treatment. In addition, an electrode is formed on the surface side of the diffusion layer to be electrically connected to the diffusion layer of each photovoltaic cell element, and a cell separation groove for separating the photovoltaic cell elements from the surface side of the photovoltaic cell element. Previous Formed cuts toward thickness direction middle portion of the resin substrate, wherein the photovoltaic cell element is a means for solving the problems with the configuration held by the resin base material in a state of being separated by the cell separation groove.

  In addition to the structure of the first invention, the photovoltaic cell integrated structure of the second invention is separated on the surface side of the photovoltaic cell element at a position avoiding the formation position of the electrode conducting to the diffusion layer. An element holding / reinforcing film is formed to prevent the dispersed photovoltaic cell elements from being held and to hold the photovoltaic cell elements, and the element holding / reinforcing film is formed of an insulating film that transmits at least one of infrared light and visible light. It is a means to solve the problem with the configuration.

  Furthermore, in the photovoltaic cell integrated structure according to the third aspect of the present invention, a diffusion layer of a different type from the silicon substrate is provided on the surface side of one of the n-type and p-type silicon substrates. A plurality of photovoltaic cell elements are arranged in the direction of the substrate surface of the silicon substrate, and the plurality of photovoltaic cell elements have a function of holding the plurality of photovoltaic cell elements on the surface side of the plurality of photovoltaic cell elements. An insulating resin base material is provided, the resin base material is configured to transmit at least one of infrared light and visible light, and the resin base material is formed by drilling processing by chemical treatment. Electrodes that are electrically connected to the diffusion layers of the respective photovoltaic cell elements are formed at the hole positions, and electrodes that are electrically connected to the silicon substrate of the respective photovoltaic cell elements are formed on the back surface side of the silicon substrate. Between cell elements A cell separation groove to be separated is formed by cutting from the back surface side of the photovoltaic cell element to a middle portion in the thickness direction of the resin substrate, and each photovoltaic cell element is held by the resin substrate in a state of being separated by the cell separation groove. It is a means to solve the problem with the configuration.

  Furthermore, in the photovoltaic cell integrated structure according to the fourth aspect of the invention, in addition to the configuration of the third aspect of the invention, at least a part of the formation position of the electrode conducting to the silicon substrate is avoided on the back side of the photovoltaic cell element. A configuration in which an insulating element holding reinforcing film that holds the separated photovoltaic cell element and prevents the separated photovoltaic cell element is formed at a position is used as a means for solving the problem.

  Furthermore, the photovoltaic cell integrated structure of the fifth invention is provided with either an n-type or p-type silicon substrate and a through-hole penetrating the silicon substrate, and at least the surface of the silicon substrate has n A photovoltaic cell element is formed by providing a diffusion layer of a type different from the silicon substrate between the mold and the p-type, and a plurality of photovoltaic cell elements are arranged in the substrate surface direction of the silicon substrate, and the plurality of photovoltaic cell elements An insulating resin base material having a function of holding the plurality of photovoltaic cell elements is provided on the back surface side of the substrate, and a hole formed by subjecting the resin base material to a drilling process by chemical treatment In this position, an electrode electrically connected to the silicon substrate of each photovoltaic cell element and an electrode electrically connected to the diffusion layer are formed, and these electrodes are arranged with a space therebetween. The cell separation groove for separating the photovoltaic cell elements is cut from the surface side of the photovoltaic cell element to the middle part in the thickness direction of the resin base material, and the photovoltaic cell elements are separated by the cell separation groove. A configuration that is held by the resin base material in a state is a means for solving the problem.

  Furthermore, the photovoltaic cell integrated structure according to the sixth aspect of the present invention is the structure of the fifth aspect of the invention, in addition to the separation of the separated photovoltaic cell elements on the surface side of the photovoltaic cell elements. An element holding / reinforcing film to be held is formed, and the element holding / reinforcing film is formed of an insulating film that transmits at least one of infrared rays and visible light, and serves as a means for solving the problem.

  Furthermore, in the photovoltaic cell integrated structure according to the seventh aspect of the invention, in addition to the structure of any one of the first to sixth aspects, the resin base material includes a phenol resin, a polyimide resin, an epoxy resin, and an acrylic resin. The structure formed of any one of the base resins or the photosensitive sheet is used as a means for solving the problem.

  Further, a photovoltaic cell device according to an eighth invention includes the photovoltaic cell integrated structure according to any one of the first to fourth inventions mounted on a mounting substrate on which a wiring pattern is formed, and the photovoltaic cell integrated structure An electrode conductive to the silicon substrate is connected to the wiring pattern of the mounting substrate via solder or conductive paste, and an electrode conductive to the diffusion layer of the photovoltaic cell integrated structure is connected to the wiring pattern of the mounting substrate via wire bonding A structure formed by connection is used as a means for solving the problem.

  Furthermore, a photovoltaic cell device of a ninth invention has the photovoltaic cell integrated structure of the fifth or sixth invention, and is formed on a resin substrate of the photovoltaic cell integrated structure, on a silicon substrate of one photovoltaic cell element. A means for solving the problem is a configuration in which a wiring for conducting the conductive electrode and an electrode conducting to the diffusion layer of the other photovoltaic cell element is provided.

  Furthermore, in the photovoltaic device of the tenth invention, in addition to the configuration of the eighth or ninth invention, the resin base material of the photovoltaic cell integrated structure includes a phenol resin, a polyimide resin, an epoxy resin, and an acrylic resin. A structure formed of any one of the base materials of the resin or the photosensitive sheet serves as means for solving the problem.

  According to the photovoltaic cell integrated structure of the present invention, an insulating resin base material having a function of holding the plurality of photovoltaic cell elements is provided on the front surface side or the back surface side of the plurality of photovoltaic cell elements. The cell separation groove for separating the photovoltaic cell elements is formed by cutting from the photovoltaic cell element to the middle portion in the thickness direction of the resin base material, and the photovoltaic cell elements are separated by the cell separation groove. Since it is held by the resin base material, a plurality of photovoltaic cell elements can be easily mounted on a mounting board such as a printed circuit board while being appropriately held on the resin base material, and a photovoltaic device can be easily formed. .

  In addition, since the resin substrate can be formed thick or thin, and even if it is formed thick, it can be easily perforated by chemical treatment, so the back surface of a plurality of photovoltaic cell elements A resin base material having an appropriate thickness can be easily provided on the side or the surface side, whereby a plurality of photovoltaic cell elements can be appropriately held, and drilling can be easily performed.

  Further, in the present invention, when an insulating element holding reinforcing film is formed on the surface side or the back side of the photovoltaic cell element forming the photovoltaic cell integrated structure, the surface holding side or back side of the photovoltaic cell element is placed on the element holding reinforcing film. The integrated structure can be reinforced and the separated photovoltaic cell elements can be prevented from being dispersed, and thus the photovoltaic cell elements can be held. For example, when the photovoltaic cell integrated structure is mounted on a mounting substrate, the photovoltaic cell It is possible to prevent the cell integrated structure from being damaged.

  Furthermore, in the photovoltaic device of the present invention, without providing a mounting substrate such as a printed circuit board, the electrode conducting to the silicon substrate of one photovoltaic cell element and the electrode conducting to the diffusion layer of the other photovoltaic cell element are conducted. In the case where the wiring to be formed is formed, a photovoltaic cell device in which photovoltaic cell elements are electrically connected to each other can be configured using semiconductor technology without mounting on the mounting substrate. Therefore, the photovoltaic device of this configuration can save space compared to the configuration mounted on a printed circuit board, can improve production efficiency, can be mass-produced, and can be supplied in large quantities to the market. In addition, the manufacturing cost can be reduced.

  Furthermore, in the present invention, when the resin substrate is formed of a phenolic resin substrate or a polyimide resin substrate, these resin substrates can be used at 300 ° C. or higher. When mounting the photovoltaic cell integrated structure or photovoltaic device on the mounting substrate, lead-free solder can be used, the heat resistance of the photovoltaic device can be improved, and the environmental load can be reduced. Applications can be expanded by improving productivity.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing a configuration diagram illustrating a first embodiment of a photovoltaic cell device according to the present invention. As shown in the figure, the photovoltaic device 20 is formed by mounting a photovoltaic cell integrated structure 33 including a plurality of photovoltaic cell elements 1 on a printed circuit board 41. In the present embodiment, a total of four photovoltaic cell elements 1 are provided in two rows and two columns as shown in the perspective view of FIG. As shown in FIGS. 1 and 2, each photovoltaic cell element 1 is formed by providing a p-type diffusion layer 4 on the surface side of an n-type silicon substrate 2, and each photovoltaic cell element 1 has its surface This is a photodiode element having the light receiving surface on the side (upper side in the figure).

  Further, a plurality (four in this case) of photovoltaic cell elements 1 are arranged in the substrate surface direction of the silicon substrate 2, and a plurality of photovoltaic cell elements 1 are arranged on the back side of the plurality of photovoltaic cell elements 1. An insulating resin base material 8 having a holding function is provided. In this embodiment, the resin substrate 8 is an ultraviolet photosensitive resin substrate, and is formed of a phenol resin substrate or a polyimide resin substrate. The thickness of the resin substrate 8 is, for example, about 5 to 200 μm.

  The resin base material 8 is subjected to a drilling process by chemical treatment, and an electrode (n-side electrode) that conducts to the silicon substrate 2 of each photovoltaic cell element 1 in the hole position formed by the drilling process. 5 is formed. On the surface side of the diffusion layer 4, an electrode (p-side electrode) 6 conducting to the diffusion layer 4 of each photovoltaic cell element 1 is formed. An element surface side protective film 9 is formed on the surface side of the photovoltaic cell element 1 at a position avoiding the position where the p-side electrode 6 is formed. The element surface side protective film 9 is made of a silicon oxide film that transmits at least one of infrared light and visible light (for example, transmits light having a wavelength of 400 nm to 1000 nm), and plays a role of protecting the surface side of the photovoltaic cell element 1. .

  In the photovoltaic cell integrated structure 33, cell separation grooves 7 for separating the photovoltaic cell elements 1 are formed by cutting from the surface side of the photovoltaic cell element 1 to the middle part in the thickness direction of the resin base material 8. The photovoltaic cell element 1 is formed by being held by the resin base material 8 in a state where it is separated by the cell separation groove 7. Thus, in this embodiment, the cell separation groove 7 is a half-cut groove formed over the middle part of the resin base material 8.

  Further, an element holding reinforcing film 10 (not shown in FIG. 2) as shown in FIG. 1 is formed on the surface side of the element surface side protective film 9. The element holding reinforcing film 10 is a film that holds the separated photovoltaic cell elements 1 and holds these photovoltaic cell elements 1. In this embodiment, the element holding reinforcing film 10 is the element surface. The side protective film 9 is formed of an insulating epoxy resin that transmits at least one of infrared light and visible light (for example, light having a wavelength of 400 nm to 1000 nm). The element holding reinforcing film 10 can also be formed of an acrylic resin, a phenol resin, or a polyimide resin.

  FIG. 3 shows a manufacturing method of the photovoltaic cell device 20 according to the present embodiment. This manufacturing method will be described with reference to FIG. First, as shown in FIG. 3A, a p-type diffusion layer 4 is formed on the surface side of an n-type silicon substrate 2 with a space therebetween.

  Then, the silicon substrate 2 is divided into a plurality of unit element regions (each region delimited by a broken line in FIG. 3A) that form the individual photovoltaic cell elements 1, and each unit element region has the diffusion layer 4 formed thereon. It is set as the structure which has. The division of the unit element region defines a boundary region separated by the cell separation groove 7 formed in a later process and the battery cutout groove 27 of the chip, and a line is drawn along each unit element region. It is not intended to mark or separate.

  Next, as shown in FIG. 3B, after the element surface side protective film 9 is formed, the element surface side protective film 9 is punched to form the p-side electrode 6 in the hole. . Since the element surface side protective film 9 is a film that protects the surface side of the photovoltaic cell element 1, the thickness thereof may be as thin as, for example, about 0.5 μm.

  Thereafter, an insulating resin base material 8 is provided on the back surface side of the photovoltaic cell element 1, and the resin base material 8 is punched by chemical treatment. This drilling process is performed, for example, by irradiating the resin substrate 8 with ultraviolet light in a state where a mask is provided at a position other than the hole position on the back surface side of the resin substrate 8, The hole 18 is formed. In addition, the order of formation of the element surface side protective film 9, formation of the p side electrode 6, and formation of the resin base material 8 is not specifically limited, It sets suitably.

  Next, as shown in FIG. 3C, an n-side electrode 5 that is electrically connected to the silicon substrate 2 of each photovoltaic cell element 1 is formed for each unit element region in the hole position formed by the drilling process. On the back side, solder 19 is provided as a conductive material for electrically connecting the n-side electrode 5 to the outside. Instead of the solder 19, another conductive material such as a conductive paste may be provided.

  Next, as shown in FIG. 3 (d), a dicing tape 43 is attached to the back side of the resin substrate 8, and cell separation grooves 7 for separating the photovoltaic cell elements 1 are formed along the boundaries of the unit element regions. Then, a cut is formed from the surface side of the photovoltaic cell element 1 to a middle portion in the thickness direction of the resin base material 8. Then, the photovoltaic cell element 1 is separated by the cell separation groove 7.

  Next, as shown in FIG. 3E, an element holding reinforcing film 10 is formed on the surface side of the element surface side protective film 9 while avoiding the formation position of the p-side electrode 6. The element holding reinforcing film 10 may be formed at a position avoiding the formation position of the p-side electrode from the beginning by providing a mask or the like, or the element holding reinforcing film 10 is also formed on the surface side of the p-side electrode 6. After that, the element holding reinforcing film 10 on the surface side of the p-side electrode 6 may be removed. In addition, since the force which hold | maintains the photovoltaic cell element 1 will become strong when the thickness of the said resin base material 8 is thickened, the thickness which can fully enlarge the holding force of the photovoltaic cell element 1 by this resin base material 8 is sufficient as this resin base material 8. When it is formed (for example, 10 μm or more), the element holding reinforcing film 10 can be omitted.

  Then, as shown in FIG. 3 (f), the silicon substrate 2 and the resin base material 8 are connected to each other by the battery cutting groove 27 of the chip along the boundary line for each group of the predetermined number of photovoltaic cell elements. Disconnect. By this cutting, a plurality of photovoltaic cell integrated structures 33 each having one cut block as one photovoltaic cell integrated structure 33 are cut out and manufactured. Here, if the dicing tape 43 is peeled off, the photovoltaic cell integrated structure 33 as shown in FIG. 1 is formed.

  As described above, the photovoltaic cell integrated structure 33 according to this embodiment is manufactured, and the resin base material 8 that is easy to process is applied, and each photovoltaic cell element 1 is separated by the cell separation groove 7. In this state, by holding the plurality of photovoltaic cell elements 1 by the resin base material 8, the photovoltaic cell integrated structure 33 can be easily manufactured.

  In this embodiment, the photovoltaic cell integrated structure 33 is formed by forming the element holding reinforcing film 10 and then cutting the chip by the battery cutting groove 27. Since the strength on the surface side can be reinforced, there is an advantage that the photovoltaic cell element 1 can be more reliably prevented from being damaged during cutting. In addition, when the photovoltaic cell integrated structure 33 is mounted on the printed circuit board 41 to form the photovoltaic device 20, the photovoltaic cell element 1 can be held by the resin base material 8 with the element holding reinforcing film 10, so that the photovoltaic cell can be reinforced. The occurrence of damage to the cell element 1 can be reduced, and the workability of the mounting work can be improved.

  As shown in FIG. 2, in this embodiment, the photovoltaic cell integrated structure 33 is formed by holding four photovoltaic cell elements 1 by a resin base material 8. Therefore, as shown in FIG. 2A, the photovoltaic cell device 20 is formed by using the photovoltaic cell integrated structure 33 to form the wiring 42 to which the n-side electrode 5 and the p-side electrode 6 of the four photovoltaic cell elements 1 are connected. Is formed in advance so as to be a target wiring circuit (so as to be a wiring circuit according to the output voltage of the photovoltaic cell device 20), and the wiring 42 and the n-side electrode 5 are connected to the solder 19 and the printed circuit board. As shown in FIG. 2B, connection is made through solder 29 provided on the wiring 42 side of 41. Further, the wiring 42 and the p-side electrode 6 are connected via the bonding wire 16 via the electrode pad 50 or the like, for example. And by this connection, the circuit which connected the four photovoltaic cell elements 1 in series is formed. The photovoltaic cell elements 1 can also be connected in parallel to form a circuit.

  In this way, the connection work for connecting the photovoltaic cell integrated structure 33 to the printed circuit board 41 is much easier than the work for mounting each photovoltaic cell element 1 on the printed circuit board 41 one by one. Thus, the photovoltaic cell device 20 can be formed by quickly and accurately mounting the plurality of photovoltaic cell elements 1 together on the printed circuit board 41. Further, the method of forming the wiring 42 is appropriately set. For example, if the wiring 42 connected to the p-side electrode 6 is collectively provided on one side of the photovoltaic cell device 20, the space for arranging the wiring 42 can be reduced. Space can also be saved.

  Next, a second embodiment of the photovoltaic device of the present invention will be described. In the description of the second embodiment, the same reference numerals are assigned to the same name portions as those in the first embodiment, and the overlapping description with the first embodiment is omitted or simplified. In the second embodiment, as shown in FIGS. 4 and 5, a plurality (four in this case) of photovoltaic cell elements 1 are arranged in the substrate surface direction of the silicon substrate 2 as in the first embodiment. The formed photovoltaic cell integrated structure 33 is mounted on the printed circuit board 41, but in the second embodiment, infrared rays are formed on the surface side of the plurality of photovoltaic cell elements 1 forming the photovoltaic cell integrated structure 33. Insulating resin base material 8 that transmits at least one of visible light (for example, transmits light having a wavelength of 400 nm to 1000 nm) is provided.

  The resin substrate 8 is formed of a phenol-based resin substrate or a polyimide-based resin substrate, and has a thickness of about 1 to 100 μm. By setting the thickness of the resin base material 8 within this range, the resin base material 8 can sufficiently obtain light transmittance, and the photovoltaic cell element 1 can be well held by the resin base material 8. Can do.

  Further, the resin base material 8 is subjected to a hole forming process by chemical treatment, and a p-side electrode 6 that is electrically connected to the diffusion layer 4 of each photovoltaic cell element 1 is formed at the hole position. An n-side electrode 5 that is electrically connected to the silicon substrate 2 of each photovoltaic cell element 1 is formed on the back surface side. And the cell separation groove | channel 7 which isolate | separates between each photovoltaic cell element 1 is cut and formed from the back surface side of the said photovoltaic cell element 1 to the middle part of the thickness direction of the said resin base material 8, and each said photovoltaic cell element 1 is said cell. It is held by the resin base material 8 in a state of being separated by the separation groove.

  Further, on the back side of the photovoltaic cell element 1, an element back side protective film 11 formed of an insulating film is formed at a position avoiding the position where the n-side electrode 5 is formed. An insulating element holding reinforcing film 12 is formed on the back side of the film 11 (avoid the formation position of the n-side electrode 5). It is preferable that the element holding reinforcing film 12 is formed of a phenol resin base material or a polyimide resin base material because lead-free solder can be used when the photovoltaic cell element 1 is mounted on the printed circuit board 41. .

  The second embodiment is configured as described above. When the photovoltaic cell integrated structure 33 is manufactured, as shown in FIG. 6A, n-type silicon is used as in the first embodiment. After the diffusion layer 4 is formed on the surface side of the substrate 2 and divided into a plurality of unit element regions (regions delimited by broken lines in FIG. 6A), as shown in FIG. 6B, the photovoltaic cell element The resin base material 8 is provided on the surface of 1 and the resin base material 8 is subjected to drilling processing by chemical treatment (the hole 18 is formed). In addition, an element back surface side protective film 11 is formed on the back surface side of the photovoltaic cell element 1.

  Then, as shown in FIG. 6C, the p-side electrode 6 that conducts to the diffusion layer 4 of each photovoltaic cell element 1 for each unit element region at the hole position formed by the drilling process of the resin base material 8. Form. Further, an n-side electrode 5 that is electrically connected to the silicon substrate 2 of each photovoltaic cell element 1 is formed on the back surface side of the silicon substrate 2. The method of forming the n-side electrode 5 is appropriately set.

  Next, as shown in FIG. 6 (d), a dicing tape 43 is provided on the front surface side of the resin base material 8, and cell separation grooves 7 for separating the photovoltaic cell elements 1 are formed from the back surface side of the photovoltaic cell element 7. The photovoltaic cell element 1 is separated by the cell separation groove 7 by cutting in the middle of the resin base material 8 in the thickness direction.

  Then, as shown in FIG. 6 (e), an element holding / reinforcing film 12 is provided on the back side of the element back side protective film 11, and as shown in FIG. 6 (f), a predetermined number of photovoltaic cell elements 1 group. The silicon substrate 2 and the resin base material 8 are cut by the battery cutout groove 27 of the chip along each boundary line. After this cutting, the dicing tape 43 is peeled off, and a plurality of photovoltaic cell integrated structures 33 as shown in FIGS. 4 and 5 are manufactured.

  Even in the second embodiment, since the element holding reinforcing film 12 is formed and then the chip is cut by the battery cutout groove 27, the strength of the back surface side of the photovoltaic cell element 1 can be reinforced at the time of cutting. There is an advantage that the photovoltaic cell element 1 can be more reliably prevented from being damaged at the time of cutting. Further, when each photovoltaic cell integrated structure 33 is mounted on the printed circuit board 41, the photovoltaic cell element 1 can be protected and the workability of the mounting operation can be improved.

  Also in the second embodiment, the photovoltaic cell integrated structure 33 is disposed on the printed circuit board 41 formed as shown in FIG. 5A, and the first embodiment as shown in FIG. 5B. Similar to the embodiment, the photovoltaic cell integrated structure 33 having the plurality of photovoltaic cell elements 1 is mounted on the printed circuit board 41 on which the wiring 42 is formed by connecting via the solder 19 to form the photovoltaic cell device 20. To do. As described above, the second embodiment can be easily manufactured and can be easily mounted as in the first embodiment, and can achieve the same effects as the first embodiment.

  Next, a third embodiment of the photovoltaic device according to the present invention will be described. In the description of the third embodiment, the same reference numerals are given to the same name portions as those in the first and second embodiments, and the overlapping description is omitted or simplified. FIG. 7 is a cross-sectional view showing the configuration of the third embodiment, and FIG. 8 schematically shows a perspective view of the cross-sectional area when viewed obliquely from below.

  As shown in these drawings, the photovoltaic device 20 of the third embodiment has a photovoltaic cell integrated structure 33 including a plurality of photovoltaic cell elements 1, and in the third embodiment, a printed circuit board is used. The photovoltaic cell device 20 is formed without providing 41.

  In the third embodiment, each photovoltaic cell element 1 forming the photovoltaic cell integrated structure 33 includes an n-type silicon substrate 2, a through hole 3 penetrating the silicon substrate 2, and a p-type diffusion layer 4. The diffusion layer 4 is formed on the surface of the silicon substrate 2, the inner wall surface of the through hole 3, and the periphery of the opening of the through hole 3 in the silicon substrate 2. An element protective film 91 is formed on the front surface side of the diffusion layer 4 and the back surface side of the silicon substrate 2. Also in the third embodiment, the plurality of photovoltaic cell elements 1 are arranged in the substrate surface direction of the silicon substrate 2, and on the back surface side of the plurality of photovoltaic cell elements 1, as in the first embodiment, An insulating resin base material 8 is provided.

  The resin base material 8 is subjected to a drilling process by a chemical treatment, and the n side electrically connected to the silicon substrate 2 of each photovoltaic cell element 1 is formed at the hole position formed by the drilling process. An electrode 5 and a p-side electrode 6 electrically connected to the diffusion layer 4 of the through hole 3 are respectively formed at appropriate positions, and the p-side electrode 6 and the n-side electrode 5 are spaced from each other. Is arranged through. Note that the p-side electrode 6 may be electrically connected to the diffusion layer 4 through a diffusion layer of the same type as the diffusion layer 4 or a conductive material formed on at least the side surface of the through hole corresponding to the diffusion layer 4.

  In the third embodiment, the cell separation groove 7 that separates the photovoltaic cell elements 1 from the surface side of the photovoltaic cell element 1 in the thickness direction of the resin base material 8 is the same as the first embodiment. The photovoltaic cell element 1 is held by the resin base material 8 in a state where the photovoltaic cell element 1 is separated by the cell separation groove 7.

  The element protective film 91 formed on the front surface side and the back surface side of the photovoltaic cell element 1 is an insulating film that transmits at least one of infrared light and visible light (for example, transmits light having a wavelength of 400 nm to 1000 nm). Insulating element holding formed on the surface side of the element protective film 91 and transmitting at least one of infrared light and visible light transmitted through the element protective film 91 (for example, transmitting light having a wavelength of 400 nm to 1000 nm) A reinforcing film 10 is formed. The element protective film 91 is formed of the same film as the element surface side protective film 9 of the first embodiment, and the element holding reinforcing film 10 is formed of the same film as the element holding reinforcing film 10 applied to the first embodiment. Has been.

  Further, in the third embodiment, the resin base material 8 is provided with a wiring 14 that conducts between the n-side electrode 5 of the one adjacent photovoltaic cell element 1 and the p-side electrode 6 of the other photovoltaic cell element 1. Has been. Thus, in the third embodiment, by forming the wiring 14 on the resin base material 8, the photovoltaic cell device 1 is formed by electrically connecting the photovoltaic cell elements 1 without providing the printed circuit board 41. ing. A protective film 15 is formed on the back side of the resin base material 8, and holes 28 are formed in the protective film 15 at the positions of the battery electrodes of the photovoltaic cell device 20.

  The third embodiment is configured as described above, and is manufactured as follows. First, as shown in FIG. 9A, a through hole 3 penetrating the silicon substrate 2 is formed in the n-type silicon substrate 2, and the surface of the silicon substrate 2, the inner wall surface of the through hole 3, and the silicon substrate 2 are formed. A p-type diffusion layer 4 is formed around the opening of the through hole 3. Further, an element protection film 91 is formed on the surface side of the diffusion layer 4, the inner wall surface of the through hole 3 (inner wall surface of the diffusion layer 4), and the back surface side of the silicon substrate 2. The through hole 3 is formed by etching the silicon substrate 2. For example, the wall surface thereof becomes a (111) crystal plane as shown in FIG.

  In addition, as long as the through hole 3 is formed through the silicon substrate 2, the formation method is appropriately set and may be formed by ion irradiation or the like. Depending on the formation method of the through hole 3, The inner wall surface may be a curved surface. Further, instead of forming the diffusion layer 4 on the inner wall surface of the through hole 3, a conductive material such as metal may be formed on the inner wall surface of the through hole 3, or a conductive material such as metal is embedded in the through hole 3. It may be formed.

  Then, the silicon substrate 2 is divided into a plurality of unit element regions (regions separated by broken lines in FIG. 9A) that form individual photovoltaic cell elements 1, and each of the unit element regions is the through-hole. The hole 3 and the diffusion layer 4 are included. In the case of the third embodiment, as in the first and second embodiments, the unit element regions are not marked or separated.

  And in the back surface side of the photovoltaic cell element 1, the element protective film 91 is perforated, and the n-side electrode 5 and the through-hole 3 that are electrically connected to the silicon substrate 2 of each photovoltaic cell element 1 are diffused into the hole. A p-side electrode 6 conducting to the layer 4 is formed with a gap therebetween.

  Next, as shown in FIG. 9B, a resin base material 8 is provided on the back surface side of the photovoltaic cell element 1, and the resin base material 8 is punched by chemical treatment. As a result, the n-side electrode 5 and the p-side electrode 6 are arranged at the hole positions where the drilling has been performed. Then, using the hole 18 formed by the drilling process, as shown in FIG. 9C, the n-side electrode 5 of one photovoltaic cell element 1 and the p-side electrode of the other photovoltaic cell element 1 which are adjacent to each other. 6 is formed. Thereafter, as shown in FIG. 9D, a protective film 15 is formed on the back surface side of the resin base material 8, and the protective film 15 is subjected to a process of opening a hole 22 for connecting battery electrodes.

  Thereafter, as shown in FIG. 9 (e), a dicing tape 43 is stretched on the back surface side of the protective film 15, and the cell separation groove 7 for separating the photovoltaic cell element 1 for each unit element region is formed in the photovoltaic cell element. The photovoltaic cell element 1 is separated by the cell separation groove 7 by cutting from the surface of 1 to the middle of the resin base material 8 in the thickness direction.

  Next, as shown in FIG. 10A, the element holding reinforcing film 10 is formed on the surface side of the element protection film 91, and as shown in FIG. 10B, a predetermined number of photovoltaic cell element groups 1 are grouped. Along each boundary line, the silicon substrate 2 and the resin base material 8 are cut by the battery cutout groove 27 of the chip, and the dicing tape 43 is peeled off to manufacture a plurality of photovoltaic cell devices 20.

  The third embodiment is manufactured as described above, and the third embodiment can achieve the same effects as the first and second embodiments, and further, the third embodiment. As described below, the effects superior to those of the first and second embodiments can be obtained.

  That is, in the third embodiment, the photovoltaic cell elements 1 can be electrically connected to each other via the wiring 14 without mounting on a mounting board such as the printed circuit board 41. Space can be saved as compared with the second embodiment. In the third embodiment, since the photovoltaic device 20 can be created only by the semiconductor creation process, the production efficiency can be improved, mass production is possible, and mass supply to the market is possible. Manufacturing costs can be reduced.

  In addition, this invention is not limited to each said embodiment, Various aspects can be taken. For example, in the first embodiment, the element holding / reinforcing film 10 is provided on the surface side of the element surface side protective film 9. In the third embodiment, the surface of the element protective film 91 formed on the surface side of the silicon substrate 2. The element holding reinforcing film 10 is provided on the side, and in the second embodiment, the element holding reinforcing film 12 is provided on the back side of the element back side protective film 11, but the element holding reinforcing films 10 and 12 may be omitted. it can. Moreover, depending on the case, the element surface side protective film 9, the element protective film 91, and the element back side protective film 11 can be omitted.

  FIG. 11 (a) shows a modification of the first embodiment, and FIG. 11 (b) shows a modification of the second embodiment. The photovoltaic cell device 20 may be formed as shown in these drawings.

  The characteristic configuration of the photovoltaic cell device 20 shown in FIG. 11A different from that of the first embodiment is that the electrode 5 is arranged not only on the hole position of the resin base material 8 but also on the entire back surface side of the silicon substrate 2. It is formed in the region. Further, the characteristic configuration of the photovoltaic cell device 20 shown in FIG. 11B different from that of the second embodiment is that the electrode 5 is arranged not only in the hole position of the element back surface side protective film 11 but also on the back surface side of the silicon substrate 2. It is formed in the whole area.

  If it is set as the structure shown to Fig.11 (a), (b), the manufacturing process of the photovoltaic cell integrated structure 33 can be simplified. For example, FIG. 12 shows a manufacturing process of the photovoltaic cell device 20 shown in FIG. 11A, and the process shown in FIG. 12 will be described below. 12A is the same as the configuration shown in FIG. 3A in the first embodiment. In the step shown in FIG. 12B, the surface side of the silicon substrate 2 is shown. The processing (formation of the electrode 6 and the protective film 9) is the same as in FIG. 3B, but as shown in FIG. 12C, the back side of the silicon substrate 2 covers the entire area on the back side. After forming the electrode 5, a resin base material 8 is provided on the back side of the electrode 5, and holes are formed at appropriate positions of the resin base material 8.

  Thereafter, as shown in FIG. 12 (d), a dicing tape 43 is provided on the back surface side of the resin base material 8, and as shown in FIG. 12 (e), cell separation grooves 7 are formed. As shown, when the battery cutout groove 27 of the chip is formed, the electrode 5 is separated for each photovoltaic cell element 1. As described above, even if the electrodes 5 are formed in the entire region on the back surface side of the silicon substrate 2, the cells can be separated for each photovoltaic cell element 1 by the cell separation grooves 7. However, the formation process can be simplified, and the manufacturing process of the photovoltaic cell integrated structure 33 can be simplified.

  As shown in FIG. 11B, when the electrode 5 is formed not only in the hole position of the element back surface side protective film 11 but also in the entire region on the back surface side of the silicon substrate 2, as shown in FIG. Thus, the photovoltaic cell integrated structure 33 can be manufactured. 13A is the same as the configuration shown in FIG. 6A in the second embodiment. In the step shown in FIG. 13B, the surface side of the silicon substrate 2 is shown. Processing (formation of the electrode 6 and the resin base material 8) is the same as in FIG. 6B, but here, the electrode 5 is formed on the back surface side of the silicon substrate 2 so as to cover the entire area on the back surface side. . Thereafter, as shown in FIG. 13C, the element back surface side protective film 11 is provided on the back surface side of the electrode 5, and holes are formed at appropriate positions of the element back surface side protective film 11. Thereby, the element back surface side protective film 11 is formed at a position avoiding a part of the formation position of the electrode 5.

  Thereafter, as shown in FIG. 12 (d), a dicing tape 43 is provided on the front surface side of the resin base material 8 to form the cell separation grooves 7, and as shown in FIG. The element holding reinforcing film 12 is formed on the rear surface side of the element 11 (the element holding reinforcing film 12 is also formed at a position avoiding a part of the formation position of the electrode 5). Thereafter, as shown in FIG. 12 (f), when the battery cutout groove 27 of the chip is formed, the electrode 5 is separated for each photovoltaic cell element 1.

  Furthermore, in the third embodiment, the wiring 14 is formed on the resin base material 8. Instead of forming the wiring 14 on the resin base material 8, solder that conducts to the n-side electrode 5 and the p-side electrode 6, respectively. 19 and a conductive material such as a conductive paste may be provided, and the n-side electrode 5 and the p-side electrode 6 may be connected to the wiring 42 via the conductive material on the printed circuit board 41 or the like on which the wiring 42 is formed.

  Further, in each of the above-described embodiments, the photovoltaic cell element 1 has the n-type silicon substrate 2 and the p-type diffusion layer 4, but the photovoltaic cell element 1 has a p-type silicon substrate. 2 and an n-type diffusion layer 4 may be employed.

  Furthermore, in the present invention, the formation material and thickness of the resin base material 8, the element surface side protective film 9, the element back side protective film 11, the element holding reinforcing film 12, and the element protective film 91 are not particularly limited, It is set appropriately. For example, the resin substrate 8 and the element holding reinforcing film 12 can be formed of an acrylic resin or an epoxy resin, a photosensitive sheet, or a resin that does not have ultraviolet sensitivity. It can also be formed.

  Furthermore, in the present invention, the number of photovoltaic cell elements 1 arranged in one photovoltaic cell device 20 and the connection method are not particularly limited, and are appropriately set according to the required output power.

It is a section lineblock diagram showing typically the 1st example of an embodiment of the photovoltaic device concerning the present invention. It is typical explanatory drawing which shows the photovoltaic device of 1st Embodiment by the perspective view of the state which cut | disconnected some front sides. It is sectional explanatory drawing which shows the manufacturing process of the photovoltaic cell integrated structure applied to the photovoltaic apparatus of 1st Embodiment. It is a section lineblock diagram showing typically the 2nd example of an embodiment of the photovoltaic device concerning the present invention. It is typical explanatory drawing which shows the photovoltaic device of 2nd Embodiment by the perspective view of the state which cut | disconnected some front sides. It is sectional explanatory drawing which shows the manufacturing process of the photovoltaic cell integrated structure applied to the photovoltaic apparatus of 2nd Example. It is a section lineblock diagram showing typically the example of a 3rd embodiment of a photovoltaic device concerning the present invention. It is typical explanatory drawing at the time of seeing the section field of the photovoltaic device of the example of the 3rd embodiment from the slanting lower side. It is sectional explanatory drawing which shows the manufacturing process of the photovoltaic device of the example of 3rd Embodiment. It is sectional explanatory drawing which shows the manufacturing process following FIG. 9 of the photovoltaic device of 3rd Example. It is a cross-sectional block diagram which shows typically the photovoltaic cell apparatus of the other embodiment of a photovoltaic cell apparatus. It is sectional explanatory drawing which shows the manufacturing process of the photovoltaic cell integrated structure applied to the photovoltaic apparatus shown to Fig.11 (a). It is sectional explanatory drawing which shows the manufacturing process of the photovoltaic cell integrated structure applied to the photovoltaic apparatus shown in FIG.11 (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photovoltaic cell element 2 Silicon substrate 3 Through hole 4 Diffusion layer 5 N electrode 6 P electrode 7 Cell separation groove 8 Resin base material 9 Element surface side protective film 10, 12 Element holding reinforcement film 11 Element back surface side protective film 27 Chip battery Cutout groove 91 Element protective film

Claims (10)

  On the surface side of one of the n-type and p-type silicon substrates, a diffusion layer of a type different from the silicon substrate is provided between the n-type and the p-type to form a photovoltaic cell element. A plurality of the silicon substrate are arranged in the substrate surface direction, and an insulating resin base material having a function of holding the plurality of photovoltaic cell elements is provided on the back side of the plurality of photovoltaic cell elements. Electrodes that are electrically connected to the silicon substrate of each of the photovoltaic cell elements are formed at least in the positions of the holes formed by subjecting the base material to a hole forming process by chemical treatment, and each photovoltaic cell is formed on the surface side of the diffusion layer. An electrode is formed to be electrically connected to the diffusion layer of the element, and a cell separation groove for separating the photovoltaic cell elements is formed by cutting from the surface side of the photovoltaic cell element to a middle portion in the thickness direction of the resin substrate. It is, photovoltaic cell integrated structure, characterized in that each of the photovoltaic cell element is held by the resin base material in a state of being separated by the cell separation groove.   On the surface side of the photovoltaic cell element, an element holding reinforcing film that holds the photovoltaic cell element while preventing the separation of the separated photovoltaic cell element is formed at a position avoiding the formation position of the electrode conducting to the diffusion layer. 2. The photovoltaic cell integrated structure according to claim 1, wherein the element holding reinforcing film is formed of an insulating film that transmits at least one of infrared light and visible light.   On the surface side of one of the n-type and p-type silicon substrates, a diffusion layer of a type different from the silicon substrate is provided between the n-type and the p-type to form a photovoltaic cell element. A plurality of the silicon substrate are arranged in the substrate surface direction, and an insulating resin base material having a function of holding the plurality of photovoltaic cell elements is provided on the surface side of the plurality of photovoltaic cell elements. The material is configured to transmit at least one of infrared light and visible light, and is electrically connected to the diffusion layer of each photovoltaic cell element at a hole position formed by subjecting the resin base material to a drilling process by chemical treatment. An electrode is formed on the back side of the silicon substrate, the electrode being electrically connected to the silicon substrate of each of the photovoltaic cell elements, and a cell separation groove for separating the photovoltaic cell elements is provided in the photovoltaic cell element Behind A photovoltaic cell integrated structure, wherein the photovoltaic cell integrated structure is cut and formed from the side to a middle portion in the thickness direction of the resin substrate, and each photovoltaic cell element is held by the resin substrate in a state of being separated by the cell separation groove body.   On the back surface side of the photovoltaic cell element, an insulating element that holds the photovoltaic cell element while preventing separation of the separated photovoltaic cell element at a position avoiding at least a part of the formation position of the electrode conducting to the silicon substrate 4. The photovoltaic cell integrated structure according to claim 3, wherein a holding reinforcing film is formed.   An n-type or p-type silicon substrate and a through hole penetrating the silicon substrate are provided, and at least on the surface of the silicon substrate, n-type or p-type diffusion different from the silicon substrate is provided. A photovoltaic cell element is formed by providing a layer, and a plurality of the photovoltaic cell elements are arranged in the substrate surface direction of the silicon substrate, and the plurality of photovoltaic cell elements are held on the back side of the plurality of photovoltaic cell elements. Insulating resin base material having a function is provided, and the resin base material is electrically connected to the silicon substrate of each photovoltaic cell element in a hole position formed by subjecting the resin base material to a drilling process by chemical treatment. And an electrode electrically connected to the diffusion layer, and these electrodes are arranged with a space between each other, and a cell separation that separates the photovoltaic cell elements from each other is formed. Is cut from the surface side of the photovoltaic cell element to the middle in the thickness direction of the resin substrate, and each photovoltaic cell element is held by the resin substrate in a state of being separated by the cell separation groove. A featured photovoltaic cell integrated structure.   On the surface side of the photovoltaic cell element, an element holding reinforcing film that holds the photovoltaic cell element while preventing the separation of the separated photovoltaic cell element is formed, and the element holding reinforcing film is at least one of infrared light and visible light 6. The photovoltaic cell integrated structure according to claim 5, wherein the photovoltaic cell integrated structure is formed of an insulating film that transmits light.   7. The resin base material according to claim 1, wherein the resin base material is formed of any one of a phenolic resin, a polyimide resin, an epoxy resin, and an acrylic resin, or a photosensitive sheet. The photovoltaic cell integrated structure according to one.   The photovoltaic cell integrated structure according to any one of claims 1 to 4 is mounted on a mounting substrate on which a wiring pattern is formed, and an electrode that conducts to a silicon substrate of the photovoltaic cell integrated structure is mounted on the mounting substrate. It is formed by connecting to the wiring pattern of the substrate via solder or conductive paste, and connecting the electrode conducting to the diffusion layer of the photovoltaic cell integrated structure to the wiring pattern of the mounting substrate via wire bonding. A characteristic photovoltaic cell device.   7. A photovoltaic cell integrated structure according to claim 5 or 6, comprising: a resin base material of the photovoltaic cell integrated structure; an electrode conducting to a silicon substrate of one photovoltaic cell element; and diffusion of the other photovoltaic cell element A photovoltaic cell device characterized in that a wiring for conducting an electrode conducting to a layer is provided.   9. The resin base material of the photovoltaic cell integrated structure is formed of a base material or a photosensitive sheet of any one of a phenol resin, a polyimide resin, an epoxy resin, and an acrylic resin, or The photovoltaic device according to claim 9.

Images