JP2001339086A - Solar battery and method of manufacturing the same, and semiconductor device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar battery and a semiconductor device which have stability and a high light-receiving efficiency, are capable of regular arrangements of semiconductor particles easily, and has a high bonding strength between a substrate and semiconductor particles, and to provide a method of manufacturing the solar battery and a method of manufacturing the semiconductor device. SOLUTION: Recessed parts 17a are formed on the surface of a substrate 17 so that each inner wall consists of a reflecting surface 17c, and a plurality of spherical cells 10 are arranged along each longitudinal direction to be mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solar cell, a semiconductor device, a method for manufacturing a solar cell, and a method for manufacturing a semiconductor device. More particularly, the present invention relates to a solar cell using spherical cells, a semiconductor device,
The present invention relates to a method for manufacturing a solar cell and a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art An internal electric field is generated at a pn junction of a semiconductor. When light is applied to the pn junction to generate an electron-hole pair, the generated electrons and holes are separated by the internal electric field.
Electrons are collected on the n side and holes are collected on the p side. When a load is connected to the outside, a current flows from the p side to the n side. Utilizing this effect, solar cells have been put into practical use as elements for converting light energy into electric energy.

In recent years, a technique has been developed in which a semiconductor element is manufactured by forming a circuit pattern on a spherical semiconductor (Ball Semiconductor) having a diameter of 1 mm or less, such as single crystal or polycrystalline silicon.

As one of the methods, a method of manufacturing a solar array in which a large number of semiconductor particles are connected using an aluminum foil has been proposed (Japanese Patent Application Laid-Open No. Hei 6-13633). In this method, as shown in FIG. 10, a semiconductor particle 207 having an n-type skin portion and a p-type interior is placed in an aluminum foil opening through an aluminum foil 201.
209 so that it protrudes from both sides of the
Is removed, and an insulating layer 221 is formed. Next, the p-type interior 21
1 and the insulating layer 221 thereon are removed, and a second aluminum foil 219 is bonded to the removed region 217.
The flat area 217 is the second aluminum foil 2 as a conductive part.
19 to provide a good ohmic contact.

[0005]

However, in such a method, there is a limit in high-density arrangement, and it is difficult to position on an aluminum foil, and particularly when a large number of semiconductor particles are mounted. There is a problem that the workability is poor and the semiconductor particles are susceptible to variations in diameter and shape of the semiconductor particles, and it is difficult to obtain a regular arrangement. In addition, there are problems in the adhesion strength between the substrate (aluminum foil) and the semiconductor particles and the stability of the joint. Also, for the formation of the electrodes, contact terminals to both the skin portion of the first conductivity type and the inside of the second conductivity type are necessary.However, it is possible to form the contact terminals reliably without reducing the light receiving area. Is difficult,
Therefore, there is a problem that the light receiving efficiency is deteriorated.

Furthermore, in order to perform stable mounting, it is necessary to increase the adhesion between the semiconductor particles and the substrate. Therefore, there is a problem that the light receiving area is reduced when the bonding area is increased.

The present invention has been made in view of the above-mentioned problems, and is stable, has high light receiving efficiency, can easily obtain a regular array, and has a high adhesion strength between a substrate and semiconductor particles. It is an object to provide a strong solar cell, a semiconductor device, a method for manufacturing a solar cell, and a method for manufacturing a semiconductor device.

[0008]

A first solar cell according to the present invention comprises a substrate having a concave portion having at least a part of a side wall constituting a reflecting surface, and a light receiving means for receiving reflected light from the reflecting surface. And a spherical cell fixed in the concave portion. According to such a configuration, by fixing the spherical cell in the concave portion, the adhesion strength between the substrate and the spherical cell is increased, and the spherical cell is chemically stable. In addition, since the inner wall of the concave portion is used as a reflection surface and the incident light is efficiently guided to the light receiving surface of the solar cell, a highly efficient and highly reliable solar cell can be obtained.

A second aspect of the present invention is the solar cell according to the first aspect, wherein a plurality of spherical cells are arranged in a row in the concave portion along the longitudinal direction. According to such a configuration, even if the spherical cells slightly vary in diameter and shape, a regular arrangement can be easily obtained.

According to a third aspect of the present invention, in the solar cell according to the first aspect, a groove is provided on a bottom surface of the concave portion, and a plurality of spherical cells are arranged in a row so as to connect the spherical cells to the groove. It is characterized by being arranged. According to this configuration, even if the spherical cells have slight variations in diameter and shape, a regular arrangement can be easily obtained, and by bonding the spherical cells to the grooves, the adhesion strength between the substrate and the spherical cells can be improved. It gets even stronger.

According to a fourth aspect of the present invention, in the solar cell according to any one of the first to third aspects, a light transmitting resin is filled in the concave portion. According to such a configuration, a stronger and more stable connection becomes possible, and the life can be greatly improved.

In a fifth semiconductor device according to the present invention, a substrate having a recess has two rows of grooves formed at a predetermined distance from each other along a longitudinal direction on a bottom surface of the recess. A plurality of spherical cells are arranged in two rows so as to be connected to the two rows of grooves. According to such a configuration, even if the spherical cells have a slight variation in shape and shape, a regular arrangement can be easily obtained, and the spherical cells are connected to the two rows of grooves in the concave portion so that the substrate and the substrate can be connected to each other. The adhesion strength of the spherical cell is increased, and it is chemically stable.

According to a sixth method of manufacturing a solar cell of the present invention, there is provided a step of preparing a substrate having a concave portion in which at least a part of a side wall constitutes a reflecting surface; A spherical cell on which a conductive semiconductor layer is formed is fixed to a concave portion of the substrate so that a plurality of spherical cells are arranged in a row along a longitudinal direction, and the substrate or a conductive pattern provided on the substrate is electrically connected. Forming a contact in the first conductive type semiconductor layer of the spherical cell;
A step of electrically connecting an electrode formed on the substrate and a contact of the first conductivity type semiconductor layer. According to this method, even if the spherical cells slightly vary in diameter and shape, a regular array can be easily formed. In addition, a solar cell having high adhesion strength between the substrate and the spherical cell and being chemically stable can be formed. Further, since the inner wall of the concave portion is used as a reflection surface and the incident light is efficiently guided to the light receiving surface of the solar cell, a highly efficient and highly reliable solar cell can be formed.

According to a seventh aspect of the present invention, there is provided a method for manufacturing a solar cell, comprising: a substrate having a plurality of recesses at least a part of a side wall of which constitutes a reflection surface, and having a groove on the bottom surface of each of the plurality of recesses Preparing and fixing a spherical cell having a second conductive type semiconductor layer formed on the surface of the first conductive type semiconductor layer such that a plurality of spherical cells are arranged in a row so as to be connected to the groove. Electrically connecting to a substrate or a conductive pattern provided on the substrate, forming a contact on a first conductivity type semiconductor layer of the spherical cell, an electrode formed on the substrate, Electrically connecting the contact of the one-conductivity-type semiconductor layer to the contact. According to this method, even if the spherical cells slightly vary in diameter and shape, a regular array can be easily formed. In addition, the adhesion strength between the substrate and the spherical cell is further increased, and a chemically stable solar cell can be formed. Further, since the inner wall of the concave portion is used as a reflection surface and the incident light is efficiently guided to the light receiving surface of the solar cell, a highly efficient and highly reliable solar cell can be formed.

According to an eighth method of manufacturing a semiconductor device of the present invention,
At least a part of the side wall has a plurality of recesses forming a reflection surface, and two rows of grooves formed at predetermined intervals on the bottom surface of each of the plurality of recesses along the longitudinal direction. Preparing a substrate having a second conductive type semiconductor layer formed on the surface of the first conductive type semiconductor layer, forming a plurality of spherical cells in such a manner as to be connected to the two rows of grooves. Fixing the substrate so as to be arranged in a row, and electrically connecting to a substrate or a conductive pattern provided on the substrate; forming a contact on the first conductive type semiconductor layer of the spherical cell; Electrically connecting the electrode formed on the first conductive type semiconductor layer and the contact of the first conductive type semiconductor layer. According to this method, even if the spherical cells slightly vary in diameter and shape, a regular array can be easily formed. In addition, a semiconductor device having stronger adhesion between the substrate and the spherical cell and being chemically stable can be formed.

According to a ninth aspect of the present invention, in the method for manufacturing a solar cell and a semiconductor device according to any one of claims 6 to 8, in the step of forming a contact on the first conductivity type semiconductor layer of the spherical cell, The method is characterized in that a contact is formed by grinding so that a part thereof is removed, and forming a bonding pad on the first conductive type semiconductor layer on the ground surface of the spherical cell. According to this method, the connection between the first conductive type semiconductor layer of the spherical cell and the electrode can be easily formed by wire bonding or the like.

According to a tenth aspect of the present invention, in the method for manufacturing a solar cell and a semiconductor device according to the ninth aspect, the ground surface of the spherical cell and the projection of the substrate are formed at the same height. Features. According to such a method, by forming the ground surface of the spherical cell and the convex portion of the substrate at the same height, when the substrate is conductive, the insulating film can be easily attached. Further, the spherical cell and the convex portion of the substrate can be ground in the same step.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a solar cell, a semiconductor device, a method of manufacturing a solar cell, and a method of manufacturing a semiconductor device according to the present invention will be described in detail with reference to the drawings.

(First Embodiment) As shown in FIG. 1, a solar cell according to a first embodiment is formed on an insulating substrate 17 so that an inner wall forms a reflection surface. The recessed portion 17a is formed, and a plurality of spherical cells are arranged in a line along the longitudinal direction and mounted.

As shown in the schematic cross-sectional view of FIG. 2, a spherical cell having a p-type semiconductor layer 11 (first conductivity type semiconductor layer) and an n-type semiconductor layer 12 (second conductivity type semiconductor layer) forming a pn junction. 10 is a conductor pattern to be an n-type electrode (not shown)
Is fixed to the concave portion 17a of the insulating substrate 17 with the conductive paste 16 and electrically connected thereto. The concave portion 17a of the insulating resin substrate 17 has a reflecting surface 17c on one of the wall surfaces surrounding the concave portion. This reflection surface 17
c is formed at such an inclination angle that the reflected light is efficiently reflected to the spherical cell 10.

The spherical cell 10 has a ground surface 10a from which a part of a sphere has been ground, and is used to electrically insulate the p-type semiconductor layer 11 and the n-type semiconductor layer 12 on the ground surface 10a. An insulating resin 14 is formed, on which a conductive resin 13 for connecting the p-type semiconductor layer 11 and the p-type electrode 15 provided on the convex portion 17b of the insulating resin substrate 17 is formed.
Are formed.

Next, an example of a specific manufacturing method will be described below. First, an example of a method of forming the spherical cell 10 used in the present invention will be described. A p-type polycrystalline silicon particle having a diameter of 1 mm is dropped while being heated in vacuum to form a p-type polycrystalline silicon sphere (p-type semiconductor layer) 11 having good crystallinity,
On this surface, an n-type polycrystalline silicon layer (n-type semiconductor layer) 12 is formed by a CVD method using a mixed gas such as silane containing phosphine. Here, in the CVD process, a thin film is formed by supplying and discharging a gas heated to a desired reaction temperature while conveying a silicon ball in a thin tube.

In this step, the p-type polycrystalline silicon particles are heated in a vacuum and dropped to form a sphere, thereby forming a p-type polycrystalline silicon sphere (p-type semiconductor layer) 11. By contact with the gas of
It is also possible to form the type polycrystalline silicon layer (n-type semiconductor layer) 12.

A thin film may be deposited outside the n-type polycrystalline silicon layer (n-type semiconductor layer) 12 by a transparent conductive film (for example, ITO) sputtering method or the like. Furthermore, by a sputtering method or the like outside the transparent conductive film,
An anti-reflection film may be formed.

Next, a method of manufacturing a solar cell using the above-described spherical cell 10 will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view of each step of manufacturing the solar cell according to the present embodiment.

As shown in FIG. 3A, an insulating resin substrate 17 having irregularities (for example, polyprosterene, acrylic, etc.) is prepared. The concave portion 17a of the insulating resin substrate 17 has a reflection surface 17c on one of the wall surfaces surrounding the concave portion. The p-type electrode 15 of the solar cell is formed on the protrusion 17b. The reflection surface 17c is formed at an angle set so that reflected light is efficiently reflected on the spherical cell 10. Further, it is preferable to coat the reflective surface 17c with a metal thin film having a high reflectivity.

Next, as shown in FIG. 3B, the spherical cell 10 having the n-type semiconductor layer 12 formed on the surface of the p-type semiconductor layer 11 is replaced with a conductive paste 16 (for example, Ag paste or the like). Are fixed so as to be in contact with the wall surface facing the reflection surface 17c in the concave portion 17a of the insulating resin substrate 17 having irregularities, and are mounted side by side regularly.

The concave portion 17a may be filled with a light-transmitting resin or the like. The light transmitting resin selected here is the concave portion 17.
It is necessary to have a refractive index capable of efficiently guiding the reflected light from the reflection surface 17c formed on the inner wall of the spherical cell 10 to the light receiving region of the spherical cell 10. As a result, a stronger and more stable connection becomes possible, and the life can be greatly improved.

Next, as shown in FIG. 3C, in order to expose the p-type semiconductor layer 11 by mechanical polishing, a part of the wall surface facing the reflection surface 17c of the spherical cell 10 is removed. Grinding.

Next, as shown in FIG. 3D, the p-type semiconductor layer 11 on the ground surface of the spherical cell 10 and the n-type semiconductor layer 1
An insulating resin 14 (for example, an epoxy resin, a silicone resin, or the like) for electrical insulation with the second resin 2 is applied.

Next, as shown in FIG. 3E, the p-type semiconductor layers 11 exposed by grinding or the p-type electrodes provided on the projections 17b of the insulating resin substrate 17 are connected. Therefore, the conductive resin 13 is applied to the ground surface. Alternatively, instead of the conductive resin 13, a conductive paste, a metal, a metal clip, a wire bond, ultrafine particles, or the like may be used.

(Second Embodiment) In a solar cell according to a second embodiment, as shown in a perspective view of a main part in FIG. 4, an inner wall is formed on a surface of a metal substrate 27 so as to form a reflection surface. Recess 27a is formed, and a groove 28 is formed on the bottom surface of the recess 27a.
And a plurality of spherical cells 10 are arranged in a row and mounted so that the spherical cells are connected to the grooves 28.

As shown in the schematic cross-sectional view of FIG. 5, the semiconductor device has a p-type semiconductor layer 11 (first conductivity type semiconductor layer) and an n-type semiconductor layer 12 (second conductivity type semiconductor layer) forming a pn junction. The spherical cell 10 is fixed to the concave portion 27a of the metal substrate 27 serving as an n-type electrode by a conductive paste 26 and electrically connected to the groove 28 in the concave portion 27a. The concave portion 27a of the metal substrate 27 has a reflection surface 27c on one of the wall surfaces surrounding the concave portion. This reflection surface 27c is
The angle of inclination is such that reflected light is efficiently reflected from the spherical cell 10.

The spherical cell 10 has a ground surface 10a from which a part of a sphere has been ground, and serves to electrically insulate the p-type semiconductor layer 11 and the n-type semiconductor layer 12 on the ground surface 10a. The insulating film 24 is formed on the ground surface 10a and the convex portion 27b.
The p-type electrode 25 of the solar cell is formed on the insulating film 24.

A highly doped polycrystalline silicon layer 11b is formed on the p-type semiconductor layer on the ground surface 10a, and a bonding pad 23 is formed on the polycrystalline silicon layer 11b.
Are formed, and the bonding pad 23 and the p-type electrode 25 are connected by a bonding wire 29.

Next, a method of manufacturing a solar cell according to the present embodiment will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view of each step of manufacturing the solar cell according to the present embodiment. The method of forming the spherical cell 10 is as described in the first embodiment.

First, as shown in FIG. 6A, a groove 28 is formed in advance in a concave portion 27a of a metal substrate 27 having irregularities (for example, Al, Cu, SUS, etc.). The concave portion 27a of the metal substrate 27 has a reflection surface 27c on a wall surface surrounding the concave portion. The reflecting surface 27c is a surface for efficiently reflecting the reflected light.
It is formed at an angle set to reflect to zero.
Further, the reflection surface 27c may be coated with a metal thin film or the like having a higher reflectance than the metal substrate 27.

Next, as shown in FIG. 6B, the spherical cell 10 is fixed so as to be engaged with the groove 28 in the concave portion 27a of the metal substrate 27, and the concave portion 27 of the metal substrate 27 having unevenness is formed.
a, and is fixed so as to be in contact with the wall surface facing the reflection surface 27c in FIG.

The concave portion 27a may be filled with a light transmitting resin or the like. The light-transmitting resin selected here is the concave 27
It is necessary to have a refractive index capable of efficiently guiding the reflected light from the reflecting surface 27c formed on the inner wall of the spherical cell 10 to the light receiving area of the spherical cell 10. As a result, a stronger and more stable connection becomes possible, and the life can be greatly improved.

Next, as shown in FIG. 6C, a part of the spherical cell 10 on the wall surface side facing the reflection surface 27c is removed by mechanical polishing so that the p-type semiconductor layer 11 is exposed. As described above, a highly doped polycrystalline silicon layer 11b is formed on the ground surface 10a of the p-type semiconductor layer by selective vapor deposition, and the bonding pad 2 is formed thereon.
3 is provided.

Next, as shown in FIG. 6D, the electrical connection between the convex portion 27b of the metal substrate 27, the p-type semiconductor layer 11 on the ground surface of the spherical cell 10, and the n-type semiconductor layer 12 is obtained. An insulating film 24 for insulation is attached.

Next, as shown in FIG. 6E, a p-type electrode 25 of the solar cell is formed on the insulating film 24 by a conductive film or a plating method.

Next, as shown in FIG. 6F, the p-type electrode 25 and the bonding pad 23 are connected by a bonding wire 29. Alternatively, a conductive paste, a metal, a metal clip, a wire bond, ultrafine particles, or the like may be used instead of the bonding wire 29.

(Third Embodiment) As shown in FIG. 7, a semiconductor device according to a third embodiment has a spherical cell 10 in each recess 37a of a metal substrate 37 having a plurality of irregularities.
Are arranged and mounted in two rows in each recess.

As shown in the schematic sectional view of FIG. 8, the semiconductor device includes a p-type semiconductor layer 11 (first conductivity type semiconductor layer) and an n-type semiconductor layer 12 (second conductivity type semiconductor layer) forming a pn junction. The spherical cell 10 has two rows of grooves 38a, 38 in the recess 37a.
The conductive paste 36 is fixed to the concave portion 37a of the metal substrate 37 so as to be related to b.

The spherical cell 10 has a ground surface 10a in which a part of a sphere is cut off, and is used to electrically insulate the p-type semiconductor layer 11 and the n-type semiconductor layer 12 on the ground surface 10a. The insulating film 34 is formed on the ground surface 10a and the convex portion 37b.
The p-type electrode 35 of the semiconductor device is formed on the insulating film 34.

A highly doped polycrystalline silicon layer 11b is formed on the p-type semiconductor layer on the ground surface 10a, and a bonding pad 33 is formed on the polycrystalline silicon layer 11b.
Are formed, and the bonding pad 33 and the p-type electrode 35 are connected by a bonding wire 33a.

Next, a method of manufacturing a semiconductor device according to the present embodiment will be described with reference to FIG. FIG. 9 is a schematic cross-sectional view of each step of manufacturing the semiconductor device according to the present embodiment. The method of forming the spherical cell 10 is as described in the first embodiment.

First, as shown in FIG. 9A, an uneven metal substrate 37 (for example, Al, Cu, SUS, etc.) is used. Two rows of grooves 38a and 38b are formed in the recess 37a.

First, as shown in FIG.
a, 38b so as to be connected to each other.
Are fixed, and are regularly arranged and mounted so as to be in contact with the wall surfaces on both sides of the metal substrate 37, respectively. Sphere cell 1 in each row
Although 0 is arranged so as not to contact as shown in the figure, it may be arranged so as to make contact.

Next, as shown in FIG. 9C, the p-type semiconductor layer 11 is exposed by mechanical polishing. As shown in the figure, grinding is performed so as to remove a part of the spherical cell 10, and a highly doped polycrystalline silicon layer 11b is formed on the ground surface 10a of the p-type semiconductor layer by selective vapor deposition, A bonding pad 33 is provided thereon.

Next, as shown in FIG. 9D, the convex portion 37b of the metal substrate 37, the p-type semiconductor layer 11 of the ground surface of the two rows of spherical cells 10 sandwiching the convex portion 37b, Insulating film 3 for electrical insulation from n-type semiconductor layer 12
Paste 4

Next, as shown in FIG. 9E, a p-type electrode 35 is formed on the insulating film 34 by a conductive film or a plating method.

Next, as shown in FIG.
Electrode 35 and two rows of spherical cells 10 sandwiching the convex portion 37b
Are respectively connected by bonding wires 39. Alternatively, a conductive paste, a metal, a metal clip, a wire bond, ultrafine particles, or the like may be used instead of the bonding wire 39.

The two rows of spherical cells 10 in the recess 37a are also provided.
, The first conductive type semiconductor layer 11 may be n-type and the second conductive type semiconductor layer 12 may be p-type. Thereby, series connection of circuits using the semiconductor device can be realized.

In each of the above embodiments, the first conductivity type will be described as p-type and the second conductivity type will be described as n-type. The same applies to the case where the first conductivity type is n-type and the second conductivity type is p-type. Can be manufactured. Although a spherical cell using a p-type polycrystal as a spherical substrate is used, a p-type single crystal or p-type amorphous silicon may be used.

In the first and second embodiments, the solar cell has been described. However, the present invention can be applied to a light emitting element. That is, by using a light emitting element such as a light emitting diode as a spherical cell, and forming a reflecting surface in the concave portion so that light from the light emitting element can be efficiently guided forward, extremely high luminous efficiency is obtained. A high light-emitting element can be obtained.

[0058]

As described above in detail, according to the solar cell, the semiconductor device, the method for manufacturing the solar cell, and the method for manufacturing the semiconductor device according to the present invention, the spherical cell is fixed in the concave portion, and the substrate Since the adhesion strength of the spherical cell is increased and the sphere cell is chemically stable, the life of the product can be extended. In addition, since the inner wall of the concave portion is used as a reflecting surface and the incident light is efficiently guided to the light receiving surface of the solar cell, the light receiving efficiency can be improved, and a highly efficient and highly reliable solar cell can be obtained. In addition, since a plurality of spherical cells are arranged in a row along the longitudinal direction in the concave portion of the uneven substrate, even if the spherical cells have slight variations in diameter and shape, regular arrangement can be easily performed. Further, by providing grooves in the concave portions, the regular arrangement can be further simplified and the adhesion strength between the substrate and the spherical cells can be increased. In addition, since the serial and parallel switching connection of the circuits is easy, the output control can be simplified. Furthermore, since the manufacturing process can be simplified,
Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a solar cell according to a first embodiment.

FIG. 2 is a schematic sectional view illustrating a solar cell according to the first embodiment.

FIG. 3 is a schematic cross-sectional view illustrating manufacturing steps (a) to (e) of the method for manufacturing a solar cell according to the first embodiment.

FIG. 4 is a perspective view of a main part of a solar cell according to a second embodiment.

FIG. 5 is a schematic cross-sectional view illustrating a solar cell according to a second embodiment.

FIG. 6 is a schematic sectional view illustrating manufacturing steps (a) to (f) of a method for manufacturing a solar cell according to a second embodiment.

FIG. 7 is a perspective view of a main part of a semiconductor device according to a third embodiment.

FIG. 8 is a schematic sectional view illustrating a semiconductor device according to a third embodiment.

FIG. 9 is a schematic sectional view illustrating manufacturing steps (a) to (f) of a method for manufacturing a semiconductor device according to a third embodiment.

FIG. 10 is a schematic sectional view illustrating a conventional solar cell.

[Explanation of symbols]

 Reference Signs List 10 spherical cell 10a ground surface 11b polycrystalline silicon layer 11 first conductive semiconductor layer 12 second conductive semiconductor layer 13 conductive resin 14 insulating resin 15, 25, 35 p-type electrode 16, 26, 36 conductive paste 17 Insulating resin substrate 17a, 27a, 37a Recess 17b, 27b, 37b Convex 17c, 27c, 37c Reflecting surface 23, 33 Bonding pad 24, 34 Insulating film 27, 37 Metal substrate (n-type electrode) 28, 38a, 38b Groove 29, 39 Bonding wire

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F051 AA02 BA11 BA17 CB27 DA01 DA03 DA20 EA01 EA17 EA20 FA16 FA17 FA30 GA03 GA11 GA20 JA02 JA14

Claims (10)

[Claims] 1. A substrate having a concave part at least a part of a side wall of which forms a reflective surface; a spherical cell fixed in the concave part so as to receive light reflected from the reflective surface;
A solar cell comprising: 2. The solar cell according to claim 1, wherein a plurality of spherical cells are arranged in a row in each of the concave portions along a longitudinal direction. 3. The method according to claim 1, wherein a groove is formed on a bottom surface of each of the concave portions, and a plurality of spherical cells are arranged in a row so as to connect the spherical cells to the grooves. Solar cell. 4. The solar cell according to claim 1, wherein a light transmissive resin is filled in the recess. 5. A substrate having a concave portion has two rows of grooves formed at a predetermined distance from each other along the longitudinal direction on the bottom surface of the concave portion, and is connected to the two rows of grooves. A plurality of spherical cells arranged in two rows as described above. 6. A step of preparing a substrate having a concave portion in which at least a part of a side wall constitutes a reflective surface; and forming a spherical cell having a second conductive type semiconductor layer formed on a surface of a first conductive type semiconductor layer. Fixing a plurality of spherical cells in a row along the longitudinal direction to the concave portion of the substrate, and electrically connecting to a conductive pattern provided on the substrate or the substrate; and Forming a contact on the first conductivity type semiconductor layer; and electrically connecting the electrode formed on the substrate and the contact of the first conductivity type semiconductor layer. Battery manufacturing method. 7. A step of preparing a substrate having a plurality of recesses at least a part of a side wall of which constitutes a reflection surface, and providing a groove having a groove on a bottom surface of each of the plurality of recesses; A spherical cell having a second conductive type semiconductor layer formed on the surface thereof is fixed so that a plurality of spherical cells are arranged in a row so as to be connected to the groove, and a substrate or a conductive pattern provided on the substrate is fixed. Electrically connecting to the first conductive type semiconductor layer of the spherical cell; electrically connecting the electrode formed on the substrate and the contact of the first conductive type semiconductor layer. A method of manufacturing a solar cell. 8. At least a part of the side wall has a plurality of recesses constituting a reflection surface, and is formed on a bottom surface of each of the plurality of recesses so as to have a predetermined interval along a longitudinal direction. Preparing a substrate having two rows of grooves, and a plurality of spherical cells having a second conductivity type semiconductor layer formed on the surface of the first conductivity type semiconductor layer so as to be connected to the two rows of grooves. Fixing the spherical cells so that the spherical cells are arranged in two rows, and electrically connecting the spherical cells to a substrate or a conductive pattern provided on the substrate; and forming a contact in the first conductive semiconductor layer of the spherical cells. And a step of electrically connecting an electrode formed on the substrate and a contact of the first conductivity type semiconductor layer. 9. A step of forming a contact on the first conductivity type semiconductor layer of the spherical cell, grinding the part so as to remove a part of the spherical cell, and forming a first surface of the ground surface of the spherical cell.
9. The method for manufacturing a solar cell and a semiconductor device according to claim 6, wherein a contact is formed by forming a bonding pad on the conductive semiconductor layer. 10. The method for manufacturing a solar cell and a semiconductor device according to claim 9, wherein the ground surface of the spherical cell and the projection of the substrate are formed at the same height.