Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberCN101088167 A
Publication typeApplication
Application numberCN 200580017453
PCT numberPCT/JP2005/021782
Publication date12 Dec 2007
Filing date28 Nov 2005
Priority date28 Nov 2005
Also published asCN101088167B, EP1870942A1, EP1870942A4, EP1870942B1, EP2219227A2, EP2219227A3, EP2219227B1, US8173895, US20080105297, US20100193028, WO2007060743A1
Publication number200580017453.4, CN 101088167 A, CN 101088167A, CN 200580017453, CN-A-101088167, CN101088167 A, CN101088167A, CN200580017453, CN200580017453.4, PCT/2005/21782, PCT/JP/2005/021782, PCT/JP/2005/21782, PCT/JP/5/021782, PCT/JP/5/21782, PCT/JP2005/021782, PCT/JP2005/21782, PCT/JP2005021782, PCT/JP200521782, PCT/JP5/021782, PCT/JP5/21782, PCT/JP5021782, PCT/JP521782
Inventors西田隆彦, 中谷光德, 森川浩昭, 唐木田升市
Applicant三菱电机株式会社
Export CitationBiBTeX, EndNote, RefMan
External Links: SIPO, Espacenet
太阳能电池单元 Solar cell translated from Chinese
CN 101088167 A
Abstract  translated from Chinese
通过具备光电变换层、在上述光电变换层的一个面一侧设置的第一电极、在上述光电变换层的另一个面一侧设置的第二电极以及在上述光电变换层的另一个面一侧在上述光电变换层的面内方向上其外缘部与上述第二电极交叠、同时将其角部作成圆角部、设置成大致四角形状并用于从上述第二电极取出输出的第三电极,得到有效地防止了与上述第二电极交叠地设置的上述第三电极的剥离的太阳能电池单元。 By providing the photoelectric conversion layer, a first electrode on one surface of the photoelectric conversion layer provided on the side of the second electrode at the other face side of the photoelectric conversion layer is disposed and the other surface side of the photoelectric conversion layer In the in-plane direction of the photoelectric conversion layer and the outer edge portion overlapping the second electrode, while its corners made round portions, disposed substantially square shape, and a third electrode from said second electrode lead-out output, effectively prevented peeling overlapping with the second electrode of said third electrode is provided a solar cell.
Claims(4)  translated from Chinese
1.一种太阳能电池单元,其特征在于具备:光电变换层;在上述光电变换层的一个面一侧设置的第一电极;在上述光电变换层的另一个面一侧设置的第二电极;以及第三电极,在上述光电变换层的另一个面一侧、在上述光电变换层的面内方向上其外缘部与上述第二电极交叠,同时将其角部作成圆角部,设置成大致四角形状,用于从上述第二电极取出输出。 A solar cell, the apparatus comprising: a photoelectric conversion layer; a first electrode on one surface of the photoelectric conversion layer provided on the side; a second electrode in the other face side of the photoelectric conversion layer disposed; and a third electrode, the other surface side of the photoelectric conversion layer, in the in-plane direction of the photoelectric conversion layer is the outer edge portion and the second electrode overlap, while being made corners rounded portion, provided a substantially rectangular shape, for the output from the second electrode lead-out.
2.如权利要求1中所述的太阳能电池单元,其特征在于:上述第二电极是铝电极,上述第三电极是银电极。 The solar cell unit according to claim 1, wherein: said second electrode is an aluminum electrode, the third electrode is a silver electrode.
3.一种太阳能电池单元,其特征在于具备:光电变换层;在上述光电变换层的一个面一侧设置的第一电极;在上述光电变换层的另一个面一侧设置的第二电极;以及第三电极,在上述光电变换层的另一个面一侧、在上述光电变换层的面内方向上其外缘部与上述第二电极交叠,同时将其角部作成倒角部,设置成大致四角形状,用于从上述第二电极取出输出。 3. A solar cell, characterized by comprising: a photoelectric conversion layer; a first electrode on one surface of the photoelectric conversion layer is provided on the side; a second electrode in the other face of the photoelectric conversion layer is disposed on one side; and a third electrode, the other surface side of the photoelectric conversion layer, in the in-plane direction of the photoelectric conversion layer is the outer edge portion and the second electrode overlap, while the corners thereof chamfered portions made, provided a substantially rectangular shape, for the output from the second electrode lead-out.
4.如权利要求3中所述的太阳能电池单元,其特征在于:上述第二电极是铝电极,上述第三电极是银电极。 4. The solar cell as described in claim 3, wherein: said second electrode is an aluminum electrode, the third electrode is a silver electrode.
Description  translated from Chinese
太阳能电池单元 Solar cell

技术领域 FIELD

本发明涉及太阳能电池单元,特别是涉及防止产生电极剥离的太阳能电池单元。 The present invention relates to a solar cell, particularly to prevent the electrode peeling of the solar cell.

背景技术 BACKGROUND

太阳光发电是使用作为无限能量的光能来发电、不释放有害物质的清洁的发电方法。 Solar power is used as the light infinite energy to generate electricity generation method does not release harmful substances clean. 在该太阳光发电中使用了作为将来自太阳的光能变换为电能以产生电力的光电变换元件的太阳能电池单元。 Used as a solar cell converting light energy from the sun into electrical energy to generate electricity in a photoelectric conversion element in the solar power generation.

通常,通过利用网板印刷在硅衬底的背面上印刷银膏和铝膏并进行干燥、烧结来形成一般生产的太阳能电池单元的受光面的背面上的电极。 Typically, by the use of screen printing on the back surface of the silicon substrate of the printed silver paste and the aluminum paste and dried, sintered to form an electrode on the back surface of the light-receiving surface of the solar cell is generally manufactured by. 在此,在硅衬底的背面的大致整个面上形成的铝起到正电极的作用。 Here, substantially the entire surface of the aluminum back surface of the silicon substrate is formed functions as the positive electrode. 但是,在制作太阳能电池模块时,不能直接在用铝形成的铝电极上焊接取出输出用的接线。 However, in the production of the solar cell module can not be directly formed on the aluminum electrode aluminum wiring out of the output of the welding. 因此,在硅衬底的背面上形成了银电极并使该银电极与铝电极部分地互相交叠作为取出输出用的电极(例如,参照专利文献1、专利文献2)。 Thus, on the back surface of the silicon substrate and a silver electrode formed of the silver electrode and the aluminum electrode partially overlap each other as electrode lead-out output (e.g., see Patent Document 1, Patent Document 2).

这样,在太阳能电池单元的衬底的背面上以部分地互相交叠的方式形成了用于实现高输出的铝电极和取出输出用的银电极。 Thus, on the back surface of the substrate of the solar cell to partially overlap each other is formed for realizing a high output of an aluminum electrode and a silver electrode out output. 而且,在该铝电极与银电极交叠的部分中,硅衬底的硅、铝电极的铝、银电极的银这三种金属部分地实现了合金化。 Further, the aluminum electrode and a silver electrode portion overlapping, the silicon of the silicon substrate, the aluminum of the aluminum electrode, a silver electrode silver three metals alloyed partially implemented.

专利文献1:特开2003-273378号公报专利文献2:特开平10-335267号公报但是,由于在烧结时急剧的加热和冷却中起因于各构件的热膨胀系数之差而产生的应力,该互相交叠的部分变得非常脆弱。 Patent Document 1: JP 2003-273378 Patent Document 2: JP-A No. 10-335267 DISCLOSURE However, due to rapid heating at the time of sintering and cooling due to the difference in thermal expansion coefficient of each member of the generated stress, the mutual overlapped portion becomes very fragile. 因此,在烧结后,例如在铝电极上交叠了银电极的情况下,在该互相交叠的部分中有时银电极的角部剥离。 Under Therefore, after sintering, for example, on a silver electrode aluminum electrode overlap case, the overlapping portion of each corner portion of the silver electrode is sometimes peeled off.

此外,为了降低太阳能电池单元的成本,有必要进一步减薄价格比率高的硅衬底。 In addition, in order to reduce the cost of the solar cell, it is necessary to further thin the silicon substrate price ratio high. 但是,如果仅谋求减薄硅衬底,则在减薄的硅衬底中,与厚的硅衬底的情况相比,起因于硅与铝的热膨胀系数之差的硅衬底的翘曲变大。 However, if only to seek thinned silicon substrate, the silicon substrate is thinned in comparison with the case of thick silicon substrate, warpage due to the difference of thermal expansion coefficient of silicon and aluminum silicon substrate becomes great.

这样,在较大地产生了硅衬底的翘曲的情况下,在烧结后的制作工序中存在产生硅衬底的裂纹使生产成品率下降或因硅衬底的裂纹使制造本身变得不可能等的问题。 Thus, to generate the next larger silicon substrate warped, after sintering in the presence of cracks in the manufacturing process of the silicon substrate so that production of cracks due to decrease in yield or the manufacturing of the silicon substrate itself becomes impossible and other problems.

作为对于这些问题的对策,例如可考虑重新评价铝膏的材料、改善电极材料的热收缩率来抑制硅衬底的翘曲的方法。 As a countermeasure for these problems, such as the aluminum paste may be considered a re-evaluation of the material, to improve the thermal shrinkage of the electrode material to suppress warpage of the silicon substrate methods. 但是,即使仅变更铝膏的材料,根据材料组合的情况,因铝与银的热收缩率之差,仍然在银电极的一部分中产生剥离。 However, even if the change is only the aluminum paste material, combination of materials according to the situation, because the difference between the thermal shrinkage of the aluminum and silver, still peeling in a part of the silver electrode.

在这样的情况下,当银电极的剥离程度较大时,也存在因太阳能电池单元的堆叠所引起的该太阳能电池单元的裂纹的产生或太阳能电池单元的特性下降而导致生产成品率下降这样的问题。 In this case, the degree of peeling when a silver electrode is large, there is generated or solar cell characteristics due to the stacking of the solar cell caused by the crack of the solar cell decline caused by the production of such a decrease in yield issue.

发明内容 SUMMARY

本发明是鉴于上述的问题而进行的,其目的在于得到有效地防止了电极剥离的太阳能电池单元。 The present invention is carried out in view of the above problems, and an object thereof is to effectively prevent the peeling of the electrode of the solar cell.

为了解决上述的课题来达到目的,与本发明有关的太阳能电池单元的特征在于具备:光电变换层;在光电变换层的一个面一侧形成的第一电极;在光电变换层的另一个面一侧形成的第二电极;以及第三电极,在光电变换层的另一个面一侧在光电变换层的面内方向上其外缘部与第二电极交叠,同时将其角部作成圆角部,设置成大致四角形状,用于从第二电极取出输出。 In order to solve the above problems to achieve the object, the present invention relates to a solar cell that includes: a photoelectric conversion layer; a first electrode on a surface side of the photoelectric conversion layer is formed; the other surface of a photoelectric conversion layer forming a second electrode side; and a third electrode, the other surface side of the photoelectric conversion layer in the in-plane direction of the photoelectric conversion layer and the second electrode which overlap the outer edge portion, while its rounded portion of the corner portion made , disposed substantially quadrangular shape, for the output from the second electrode lead-out.

对于与本发明有关的太阳能电池单元来说,通过在具备光电变换层、在光电变换层的一个面一侧形成的第一电极和用于从在光电变换层的另一个面一侧设置的第二电极取出输出的第三电极的太阳能电池单元中这样来设置第三电极,使其外缘部与第二电极交叠、同时将其角部作成圆角部、设置成大致四角形状,由于即使在第三电极的角部中也能可靠地键合该第三电极与第二电极,故起到可实现有效地防止了第三电极的剥离的太阳能电池单元这样的效果。 For the solar cell with the present invention is concerned, by the availability of the photoelectric conversion layer, a first electrode on a surface side of the photoelectric conversion layer is formed from one side and to the other surface disposed on a first photoelectric conversion layer Second electrode lead-out electrode of the output of the third solar cell in this way to set the third electrode to the second electrode overlap with the outer edge portion, while its corners made round portions, disposed substantially rectangular shape, since even in the the corner portion of the third electrode can be reliably bonded to the third electrode and the second electrode, so play can be achieved effectively prevents such an effect of the peeling of the third electrode solar battery cell.

此外,与本发明有关的太阳能电池单元起到下述的效果:即使在谋求为了降低太阳能电池单元成本的硅衬底的减薄的情况下,也没有象现有技术那样在硅衬底中产生多个衬底裂纹的情况,可充分地予以对应,可增加可使用的材料种类的选择自由度。 In addition, the solar cell with the present invention plays the following effects: the case of seeking to reduce thinning of the cost of silicon solar cell substrates, unlike the prior art has not produced in the silicon substrate even in a plurality of substrates crack case, be sufficiently correspond, the type of material that can be used to increase the freedom of choice.

而且,由于与本实施形态有关的太阳能电池单元将第三电极的角部作成了圆角部,故可减小第三电极的面积,可削减电极材料的使用量。 Further, since the present embodiment in the corner of the solar cell as a portion of the third electrode became rounded portion, it is possible to reduce the area of the third electrode, the amount of the electrode material can be reduced. 由此,与本实施形态有关的太阳能电池单元起到可谋求材料费的削减、可实现廉价的太阳能电池单元这样的效果。 Thus, with this embodiment of the solar cell may be seeking to play the material cost reduction, such an effect can be achieved cheap solar cell.

附图说明 Brief Description

图1-1是表示与本发明的实施形态1有关的太阳能电池单元的示意结构的剖面图。 Figure 1-1 shows the embodiment of the present invention is a schematic sectional view relating to the structure of the solar cell.

图1-2是表示与本发明的实施形态1有关的太阳能电池单元的表面一侧(受光面一侧)的示意结构的平面图。 Figure 1-2 is a plan view of an embodiment of the present invention relating to the surface side of the solar cell (light receiving surface side) of the schematic structure.

图1-3是表示与本发明的实施形态1有关的太阳能电池单元的背面一侧(与受光面相反的面一侧)的示意结构的平面图。 Figure 1-3 is a view of an embodiment of the present invention is related to the back side of the solar cell (opposite to the light receiving surface and the receiving surface side) plan view showing a schematic structure.

图1-4放大地表示在与本发明的实施形态1有关的太阳能电池单元中硅、铝、银这三种金属部分地合金化后的合金部的周边。 Figure 1-4 shows an enlarged scale in the periphery of an embodiment of the present invention is related to the solar cell silicon, aluminum, silver three partially alloying metal alloy portion.

图1-5是放大地表示在与本发明的实施形态1有关的太阳能电池单元的背面上设置的铝电极和背面银电极部分地交叠后的区域B和区域C的周边部的剖面图。 Figure 1-5 is an enlarged cross-sectional view showing the peripheral portion of the region B and the region C the aluminum electrode and the back-surface silver electrode portion on a back surface with an embodiment of the present invention is related to a solar cell arranged to overlap after.

图2是放大地表示在现有的太阳能电池单元的背面上设置的铝电极和背面银电极部分地交叠的区域B'和区域C'的周边部的剖面图。 Figure 2 is an enlarged cross-sectional view provided on the back surface of a conventional solar cell rear surface aluminum electrode and a silver electrode region B partially overlapping 'and region C' of the peripheral portion of FIG.

图3-1是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-1 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图3-2是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-2 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图3-3是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-3 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图3-4是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-4 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图3-5是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-5 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图3-6是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-6 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图3-7是表示在与本发明的实施形态1有关的太阳能电池单元的制造中在银膏的印刷中使用的网板掩模的一例的平面图。 Figure 3-7 is a plan view showing the embodiment of the present invention is the manufacture of a solar cell related to use in the printing of a silver paste in one example of screen mask.

图3-8是表示在与本发明的实施形态1有关的太阳能电池单元的制造中在银膏的印刷中使用的网板掩模的一例的剖面图。 Figure 3-8 is a sectional view showing the manufacturing of an embodiment of the present invention is related to a solar cell used in the printing silver paste in the example of screen mask.

图3-9是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-9 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图3-10是说明与本发明的实施形态1有关的太阳能电池单元的制造方法的剖面图。 Figure 3-10 is an explanatory view showing a method of Embodiment 1 of the present invention is related to a solar cell.

图4-1是用于说明应用了本发明的实施形态1的具体的太阳能电池单元的背面一侧(与受光面相反的面一侧)的尺寸的平面图。 Figure 4-1 is a view for explaining the application of the specific embodiment of the invention the back side (opposite to the light receiving surface and the receiving surface side) of the size of a plan view of a solar battery cell.

图4-2是用于说明应用了本发明的实施形态1的具体的太阳能电池单元的背面银电极的形状和尺寸的平面图。 Figure 4-2 is a plan view for explaining the back-surface silver electrode specific embodiment of the present invention the solar cell of a shape and dimensions.

图5-1是表示与本发明的实施形态2有关的太阳能电池单元的背面一侧(与受光面相反的面一侧)的示意结构的平面图。 Figure 5-1 is a diagram showing Embodiment 2 of the invention related to the back side of the solar cell (opposite to the light receiving surface and the receiving surface side) plan view showing a schematic structure.

图5-2放大地表示在与本发明的实施形态2有关的太阳能电池单元中硅、铝、银这三种金属部分地合金化后的合金部的周边。 Figure 5-2 shows an enlarged periphery after the embodiment 2 of the invention related to the solar cell silicon, aluminum, silver three metals partially alloyed alloy portion.

图5-3是放大地表示在与本发明的实施形态2有关的太阳能电池单元的背面上设置的铝电极和背面银电极部分地交叠的区域D和区域E的周边部的剖面图。 Figure 5-3 is an enlarged cross-sectional view of the aluminum electrode and the back-surface silver electrode partially overlapping regions D and E of FIG region on the back surface of the peripheral portion of Embodiment 2 of the present invention is related to a solar cell provided.

图6-1是用于说明应用了本发明的实施形态2的具体的太阳能电池单元的背面一侧(与受光面相反的面一侧)的尺寸的平面图。 Figure 6-1 is a view for explaining the application of the specific embodiment of the invention the back side (opposite to the light receiving surface and the receiving surface side) plan view dimensions of the solar cell 2.

图6-2是用于说明应用了本发明的实施形态2的具体的太阳能电池单元的背面银电极的形状和尺寸的平面图。 6-2 is a plan view for explaining the back-surface silver electrode specific embodiment of the present invention the solar cell 2 shape and size.

符号的说明10半导体层部11硅衬底13n型扩散层13an型扩散层14p+层15反射防止膜17铝电极17a铝膏层19背面银电极19a银膏层21表面银电极21a银膏层23合金部25网格27乳剂31背面银电极33合金部具体实施方式以下,根据附图详细地说明与本发明有关的太阳能电池单元的实施形态。 SYMBOLS 10 of the semiconductor layer portion 11 of the silicon substrate 13n-type diffusion layer 13an layer 14p + -type diffusion layer 15 of the antireflection film 17 is an aluminum paste layer 17a aluminum electrode 19 back-surface silver electrode silver paste layer 19a 21 21a-surface silver electrode silver paste layer 23 alloy 25 mesh 27 33 emulsion 31 on the back of a silver alloy electrode specific embodiments will be described below in detail with the accompanying drawings embodiments of the present invention is related to a solar cell according to. 再有,本发明不限定于以下的描述,在不脱离本发明的要旨的范围内,可适当地变更本发明。 Further, the present invention is not limited to the following description, without departing from the scope of the gist of the present invention, the present invention can be suitably changed. 此外,在以下的附图中,为了容易理解起见,有时各附图间的缩放比例和各构件间的缩放比例与实际不同。 Further, in the following drawings, for easy understanding purposes, sometimes scaling scaling between the drawings and the respective members between different from the actual.

实施形态1. Embodiment 1.

图1-1~图1-3表示与本发明的实施形态1有关的太阳能电池单元的示意结构,图1-1是表示与实施形态1有关的太阳能电池单元的示意结构的剖面图。 Figure 1-1 to Figure 1-3 shows the embodiment of the present invention is related to a schematic structure of a solar cell, Figure 1-1 shows a first embodiment 1 a schematic sectional view relating to the structure of the solar cell. 此外,图1-2是表示与实施形态1有关的太阳能电池单元的表面一侧(受光面一侧)的示意结构的平面图,图1-3是表示与实施形态1有关的太阳能电池单元的背面一侧(与受光面相反的面一侧)的示意结构的平面图。 In addition, FIG. 1-2 is a plan view showing a first embodiment related surface side of the solar cell (light receiving surface side) of the schematic structure, and Fig 1-3 shows a first embodiment related to the back surface of a solar cell side (opposite to the light receiving surface side and receiving side) plan view showing a schematic structure. 再有,图1-1是图1-3的线AA的剖面图。 Further, FIG. 1-1 is a line AA of FIG. 1-3 cross-sectional view.

与本实施形态有关的太阳能电池单元,如图1-1~图1-3中所示,具备下述部分而构成:由作为半导体衬底的p型硅衬底即p型层11、该p型层11的表面的导电类型反转后的n型扩散层13和包含高浓度杂质的p+层(BSF层:背面场)14构成的作为光电变换层的半导体层部10;在该半导体层部10的受光面上设置以防止入射光的反射的反射防止膜15;在该半导体层部10的受光面上设置成大致棒状的作为受光面电极部的表面银电极21;以取出电力和入射光的反射为目的在半导体层部10的背面的大致整个面上设置的作为背面电极部的铝电极17;以及用于从该铝电极17取出电力的作为取出电极部的背面银电极19。 With this embodiment of the solar cell, as shown in Figure 1-1 to Figure 1-3, have the following part constituted by: a semiconductor substrate of p-type silicon substrate, i.e., p-type layer 11, the p conductivity type n-type diffusion layer 11 of the surface-type inverted layer 13 containing a high concentration of impurities and the p + layer: as a photoelectric conversion layer composed of a semiconductor layer portion (BSF layer back surface field) 14 10; in the semiconductor layer portion the light receiving surface 10 is provided to prevent the reflection of incident light reflection prevention film 15; the semiconductor layer of the light receiving surface 10 is disposed substantially rod-receiving surface of the silver electrode as a surface electrode portion 21; and the incident light to remove electricity an aluminum electrode is used as a reflective back electrode portion 17 in substantially the entire surface of the object back surface portion of the semiconductor layer 10 is provided; and a back-surface silver electrode 19 is taken out from the electrode portion 17 of the aluminum electrode is used as the power out.

在这样构成的与本实施形态有关的太阳能电池单元中,如果太阳光从太阳能电池单元的受光面一侧(反射防止膜15一侧)照射并到达内部的pn结面(p型层11与n型扩散层13的结面),则在该pn结面上的电子空穴对的空穴与电子分离。 In the present embodiment in the solar cell thus constructed, if the light receiving surface side of sunlight from the solar cell (antireflection film 15 side) is irradiated and reach the internal pn-junction (p-type layer 11 and n junction) type diffusion layer 13, the electron-hole separation in the pn junction surface of the holes and electrons. 分离的电子朝向n型扩散层13移动。 Separated electrons toward the n-type diffusion layer 13 is moved. 另一方面,分离的空穴朝向p+层14移动。 On the other hand, the separated holes move toward the p + layer 14. 由此,在n型扩散层13与p+层14之间产生电位差,使p+层14的电位提高。 Accordingly, between the n-type diffusion layer 13 and the p + layer 14 to produce a potential difference, the potential of the p + layer 14 is improved. 其结果,与n型扩散层13连接的表面银电极21成为正极,与n型扩散层13连接的铝电极17成为负极,在外部电路(未图示)中流过电流。 As a result, the surface silver electrodes 13 are connected to the n-type diffusion layer 21 serves as a cathode, and an aluminum electrode 13 is connected to the n-type diffusion layer 17 serves as an anode, the external circuit (not shown), a current flows.

接着,说明与本实施形态有关的太阳能电池单元的特征。 Next, a feature of this embodiment of the solar cell. 如图1-3和图1-4中所示,在与本实施形态有关的太阳能电池单元中,在p+层14上铝电极17与背面银电极19部分地交叠。 As shown in FIG. 1-3 and 1-4, in the present embodiment in the solar cells, the p + layer 19 on the aluminum electrode 17 and the back part, the silver electrode 14 overlap. 图1-4放大地表示图1-3的平面图中的背面银电极19的周边,放大地表示在太阳能电池单元的背面上设置的铝电极17与背面银电极19部分地交叠的部分。 Figure 1-4 shows an enlarged plan view of Figures 1-3 outside the back-surface silver electrode 19, an enlarged scale, the aluminum electrode on the back surface of the solar cell 17 provided with the back-surface silver electrode 19 partially overlapping portions. 此外,图1-5放大地表示图1-1的剖面图中的背面银电极19的周边,是放大地表示在太阳能电池单元的背面上设置的铝电极17和背面银电极19部分地交叠的区域B和区域C的周边部的剖面图。 Furthermore, Figure 1-5 shows an enlarged cross-sectional view 1-1 of FIG surrounding the back-surface silver electrode 19, is an enlarged back-surface silver electrodes 17 and 19 partially overlap the aluminum electrode on the back surface of the solar cell disposed The region B and region C in cross-sectional view of the peripheral portion.

在该铝电极17与背面银电极19部分地交叠的区域B和区域C中,硅衬底的p+层14的硅、铝电极17的铝、背面银电极19的银这三种金属部分地合金化,如图1-4和图1-5中所示,形成了合金部23。 In the aluminum 17 and the region B and region C back-surface silver electrode 19 partially overlapping electrode, the silicon substrate 14 of p + silicon layer, aluminum, silver back-surface silver electrode 19 of the aluminum electrode 17 of the three metal part alloying, as shown in FIG. 1-4 and FIG. 1-5, the alloy portion 23 is formed. 再有,在图1-1和图1-5中,对于区域B和区域C,各金属(硅、铝、银)的边界是清晰的,但由于该部分部分地被合金化,故实际上当然是不清晰的。 Further, in the Figure 1-1 and Figure 1-5, for the area B and area C, each metal (silicon, aluminum, silver) is a clear boundary, but since the portions being alloyed, it actually Of course, it is not clear.

在此,在与本实施形态有关的太阳能电池单元中,如图1-3和图1-4中所示,背面银电极19在硅衬底的面内方向上呈大致四角形(长方形)。 Here, in the present embodiment in the solar cell, as shown in 1-3, and a substantially rectangular (rectangle) shown in Figures 1-4, back-surface silver electrode 19 was in the in-plane direction of the silicon substrate. 而且,背面银电极19在大致四角形(长方形)的角部中呈曲线形状。 Further, back-surface silver electrode 19 at a substantially quadrilateral (rectangular) in a corner portion curved shape. 详细地说,将背面银电极19的大致四角形(长方形)的角部作成了圆角部。 In detail, the back-surface silver electrode is substantially rectangular (rectangular) as the corner portion 19 become rounded portion.

由此,在与本实施形态有关的太阳能电池单元中,如图1-5中所示,在铝电极17和背面银电极19部分地交叠的区域B和区域C中可靠地形成合金部23,即使在背面银电极19的端部中,也可靠地键合了背面银电极19与铝电极17。 Accordingly, in the present embodiment in the solar cell, shown in Figure 1-5, in the region 17 and the regions B and C back-surface silver electrode 19 partially overlapping the aluminum electrode portion 23 is reliably formed alloy , even in the back end portion of the silver electrode 19, but also reliably bonded to the back-surface silver electrode 19 and aluminum electrode 17.

在现有的太阳能电池单元中,背面银电极19的形状在硅衬底面内方向上呈大致四角形(长方形),将该大致四角形(长方形)的角部作成了大致直角。 In the conventional solar cell, the shape of the back-surface silver electrode 19 on a silicon substrate in-plane direction substantially quadrangular (rectangular), the approximately rectangular (rectangle) as the corner portion become substantially right angle. 而且,即使在现有的太阳能电池单元中也与本实施形态的太阳能电池单元同样,如图2中所示,也具有铝电极17和背面银电极19部分地交叠的区域B'和区域C'。 Moreover, even in the conventional solar cell in this embodiment also the solar cell Similarly, shown in Figure 2, also has a back-surface silver electrodes 17 and 19 partially overlap in areas B 'and C aluminum electrode area '.

在这样的太阳能电池单元中,该互相交叠的部分因在制造中途的烧结时的急剧的加热工序和冷却工序中产生的、起因于各构件的热膨胀系数之差而产生的应力的缘故变得非常脆弱。 In such a solar cell, which overlap each other in part by way of manufacture during sintering abrupt heating step and cooling step generated sake stress difference in coefficient of thermal expansion of the respective members due to be generated is very fragile. 因此,在烧结后,在该铝电极17和背面银电极19部分地交叠的区域B'和区域C'中,如图2的区域C'中所示,在背面银电极19的角部中,有时背面银电极19从铝电极17剥离。 Therefore, after sintering, the aluminum 17 and the back-surface silver electrode 19 region B partially overlap 'and region C' electrode, as shown in region C 2 of the 'illustrated, the corners of the back-surface silver electrode 19 sometimes back-surface silver electrode 19 is peeled from the aluminum electrode 17. 而且,该应力容易集中于背面银电极19的锐利的角部。 Moreover, the stress tends to concentrate on sharp back-surface silver electrode 19 of the corner portion. 即,因该应力的集中,在背面银电极19的锐利的角部中不能正常地形成合金部23,存在从该直角角部产生背面银电极19的剥离的趋势。 That is, due to the concentrated stress, in the back-surface silver electrode 19 is a sharp corner portion can not be formed properly in the alloy portion 23, the presence of back-surface silver electrode to generate trend 19 is peeled off from the right-angle corners.

因此,在与本实施形态有关的太阳能电池单元中,为了消除背面银电极19的锐利的角部而将角部作成了圆角部,以免应力集中于背面银电极1 9的角部。 Thus, in the present embodiment in the solar cell in order to eliminate sharp corners and back-surface silver electrode 19 as the corner portions become rounded portion, so as to avoid stress concentration on the corner portion 19 of the back-surface silver electrode. 由此,在与本实施形态有关的太阳能电池单元中,可缓和集中于背面银电极19的角部的应力,如图1-5中所示,在铝电极17和背面银电极19部分地交叠的区域B和区域C中可靠地形成合金部23,提高了铝电极17与背面银电极19间的键合力、铝电极17和背面银电极19的衬底键合力。 Accordingly, in the present embodiment in the solar cell, will ease the stress concentrated on the corner portion of the back-surface silver electrode 19, shown in Figure 1-5, the back-surface silver electrodes 17 and 19 partially cross aluminum electrode overlapping areas B and C in the region 23 to form an alloy reliably improve the aluminum electrodes 17 and 19 keys back together silver electrode and aluminum electrode substrate bonding force 17 and 19 on the back of a silver electrode. 因而,按照与本实施形态有关的太阳能电池单元,起到即使在背面银电极19的角部中也可靠地键合背面银电极19与铝电极17从而可实现有效地防止了背面银电极19的剥离的太阳能电池单元的效果。 Thus, in accordance with this embodiment of the solar cell, even when played back-surface silver electrode at the corner portion 19 is also securely bonded to the aluminum back-surface silver electrode 19 and the electrode 17 which allows for effectively preventing the back-surface silver electrode 19 effect peeling of the solar cell.

在圆角尺寸R比合金部23的尺寸大的情况下,不能部分地形成铝电极17与背面银电极19的合金部,作为背面银电极19是不适当的。 In the fillet R larger than the size of the alloy portion 23 of the case size, can not be partially formed silver alloy portion 17 and the back electrode 19 aluminum electrode, as the back-surface silver electrode 19 is inappropriate. 因而,如图1-4中所示,有必要以能可靠地形成合金部23的方式来决定决定合金部23的尺寸的铝电极17和背面银电极19在背面银电极19的长边方向上交叠的部分的尺寸L1、L3和铝电极17和背面银电极19在背面银电极19的短边方向上交叠的部分的尺寸L5、L7的值。 Thus, shown in Figure 1-4, it is necessary to be able to reliably manner alloy portion 23 is formed to determine the longitudinal direction 19 back-surface silver electrode 19 on the decision of the size of the alloy portion 23 of the aluminum electrode 17 and the back-surface silver electrode portion overlapping dimension L1, L3, and aluminum electrode 17 and the portion of the back-surface silver electrode 19 dimension L5 in the shorter side direction of the back-surface silver electrode 19 overlap, the value of L7. 另外,如后述那样利用网板印刷形成铝电极17和背面银电极19,也应考虑铝膏和银膏的印刷时的位置偏移来决定上述尺寸。 Further, as described later are formed by screen printing the aluminum electrode 17 and the back-surface silver electrode 19, should also consider the location of the offset printing an aluminum paste and silver paste to determine the time of the above dimensions.

此外,在现有的太阳能电池单元中,在为了降低太阳能电池单元的成本而谋求硅衬底的减薄的情况下,与使用了厚的硅衬底的情况相比,起因于硅与铝的热膨胀系数之差的硅衬底的翘曲变大。 Furthermore, in conventional solar battery cells, in order to reduce the cost of the solar cell and seek a silicon substrate thinned, with a thickness of the case of using the silicon substrate as compared, caused by the silicon and aluminum warping the difference in thermal expansion coefficient of the silicon substrate becomes large. 而且,在较大地产生了硅衬底的翘曲的情况下,在烧结后的制造工序中存在产生硅衬底的裂纹使生产成品率下降或因硅衬底的裂纹使制造本身变得不可能等的问题。 Moreover, in the next generation greatly warped silicon substrate, in the presence of the manufacturing process after sintering cracks silicon substrate so that the production yield due to cracking or decrease the manufacturing silicon substrate itself becomes impossible and other problems.

即使在变更铝电极的材料、改善电极材料的热收缩率来抑制硅衬底的翘曲作为对于这些问题的对策的情况下,根据材料组合的情况,因铝与银的热收缩率之差也在背面银电极的一部分中产生剥离。 Under countermeasure for these issues, the combination of materials according to the situation, because the difference between the thermal shrinkage of the aluminum and silver aluminum electrode even when the change material, to improve the thermal shrinkage of the electrode material to suppress warpage of the silicon substrate, as also peeling in a part of back-surface silver electrode. 而且,在背面银电极的剥离程度较大的情况下,与由太阳能电池单元的堆叠引起的该太阳能电池单元的裂纹的产生或太阳能电池单元的特性下降有关,引起生产成品率下降这样的问题。 Moreover, in the larger degree peel back silver electrode case, with the characteristics produced by the solar cell or the solar cell caused by stacking the solar cell of the decrease of cracks, causing production problems such as decreased yield.

但是,在与本实施形态有关的太阳能电池单元中,如上所述,提高了在硅衬底的背面上形成的铝电极17与背面银电极19间的键合力、铝电极17和背面银电极19的与硅衬底的键合力,可有效地防止背面银电极19的剥离或铝电极17的剥离。 However, in the present embodiment in the solar cell, as described above, to improve the aluminum electrode on the back surface of the silicon substrate 17 formed with a key 19 of the back-surface silver electrode force, the aluminum electrode 17 and the back-surface silver electrode 19 and the bonding force of the silicon substrate, peeling the peeling can be effectively prevented or aluminum electrode 19 back-surface silver electrode 17. 由此,可使铝电极17与背面银电极19间的键合、铝电极17和背面银电极19的与衬底的键合变得可靠。 By this, the aluminum electrode 17 and the back of the silver electrode 19 is bonded, and aluminum electrodes 17 and 19 on the back of a silver electrode substrate together with the bond becomes reliable.

因而,按照与本实施形态有关的太阳能电池单元,起到下述的效果:即使在为了降低太阳能电池单元的成本而减薄硅衬底的情况下,也没有像现有技术那样在硅衬底中产生多个衬底裂纹的情况,可充分地予以对应,可增加可使用的银膏种类的选择自由度。 Thus, in accordance with this embodiment of the solar cell, play the following effect: even in the case in order to reduce the cost of the solar cell and the thinning of the silicon substrate, the prior art did not like in the silicon substrate generating a plurality of substrates in the case of cracks, can be sufficiently correspond, the silver paste may be used to increase the freedom of choice of the kind.

再者,在与本实施形态有关的太阳能电池单元中,由于将在现有的太阳能电池单元的背面银电极中理应存在的锐利的角部作成圆角部,故背面银电极19的面积变小,削减了在背面银电极19中使用的银膏的量。 Furthermore, in the present embodiment in the solar cell, since the sharp corners at the back of the conventional silver electrode of the solar cell should be made present in round portions, and the area of back-surface silver electrode 19 becomes small , reducing the amount used in the 19 back of the silver electrode silver paste. 因而,按照与本实施形态有关的太阳能电池单元,起到可谋求材料费的削减、可实现廉价的太阳能电池单元这样的效果。 Thus, in accordance with this embodiment of the solar cell, may play a seek material cost reduction, such an effect can be achieved cheap solar cell. 在后面叙述银膏的具体的削减效果。 In particular the silver paste described later reduction effect.

接着,说明如上述那样构成的与本实施形态有关的太阳能电池单元的制造方法。 Next, a manufacturing method of the present embodiment in a solar cell configured as described above. 为了制造与本实施形态有关的太阳能电池单元,首先,如图3-1中所示,例如对利用提拉法制造的p型的单晶硅锭或利用铸造法制造的多晶硅锭进行切片,得到p型的硅衬底11'。 To manufacture the present embodiment in the solar cell, first, as shown in Figure 3-1, for example, by a pulling method for producing a p-type single crystal silicon ingot or an ingot casting method using a polysilicon fabricated sliced to give p-type silicon substrate 11 '. 然后,例如用约几wt%~20wt%的氢氧化钠或碳酸氢氧化钠刻蚀除去约10μm~20μm的厚度,除去切片时产生的硅表面的损伤层及污染等。 Then, for example, about several wt% ~ 20wt% of sodium hydroxide or sodium carbonate removed by etching a thickness of about 10μm ~ 20μm, and pollution removal of the damaged layer produced by slicing the silicon surface and the like.

再者,根据需要用盐酸和过氧化氢的混合溶液清洗,除去在衬底表面上附着的铁等的重金属类。 Further, if necessary using a mixed solution of hydrochloric acid and hydrogen peroxide water to remove heavy metals such as iron adhered on the substrate surface. 其后,用在同样的碱性低浓度液中添加了IPA(异丙醇)的溶液进行各向异性刻蚀,例如形成纹理(texture)以使硅(111)面露出。 Thereafter, in the same low concentration of alkaline solution added IPA (isopropyl alcohol) was subjected to anisotropic etching, for example, a texture (texture) to the silicon (111) plane is exposed.

接着,为了形成pn结而形成n型扩散层13a。 Next, in order to form a pn junction and an n-type diffusion layer 13a. 在该n型扩散层13a的形成工序中,例如使用氯氧化磷(POCl3),在800℃~900℃的氮、氧的混合气体气氛中进行扩散处理,如图3-2中所示,热扩散磷,在硅衬底11'的整个面上形成导电类型反转后的n型扩散层13a。 In the step of forming the n-type diffusion layer 13a, for example using phosphorus oxychloride (POCl3), nitrogen diffusion treatment at 800 ℃ ~ 900 ℃ and oxygen mixed gas atmosphere, as shown in Figure 3-2, the heat diffusion of phosphorus in the silicon substrate 11 'of the entire surface of an n-type diffusion layer 13a of the reversed conductivity type. 再有,该n型扩散层13a的薄层电阻例如约为几十(30~80~Ω/□,n型扩散层13a的深度例如约为0.3μm~0.5μm。 Further, the n-type diffusion layer 13a for example, a sheet resistance of about several tens (30 ~ 80 ~ Ω / □, depth of the n-type diffusion layer 13a for example, about 0.3μm ~ 0.5μm.

接着,为了保护受光面一侧的n型扩散层13a,用网板印刷法印刷高分子抗蚀剂膏并使其干燥以形成抗蚀剂。 Next, in order to protect the n-type diffusion layer side of the light-receiving surface 13a, a polymer resist printing paste by screen printing method and dried to form a resist. 然后,例如在20wt%的氢氧化钾溶液中浸渍几分钟,除去在硅衬底11'的背面及侧面上形成的n型扩散层13a。 Then, for example, 20wt% of potassium hydroxide solution was immersed a few minutes, to remove n-type diffusion layer 13a on the silicon substrate 11 'is formed on the back surface and side surfaces. 其后,用有机溶剂除去抗蚀剂,如图3-3中所示,得到在表面(受光面)的整个面上形成了n型扩散层13的硅衬底11'。 Thereafter, the resist was removed with an organic solvent, as shown in Figure 3-3, the entire surface to obtain a surface (light receiving surface) of the n-type silicon substrate forming a diffusion layer 13 of 11 '.

接着,如图3-4中所示,在n型扩散层13的表面上以一样的厚度形成氧化硅膜、氮化硅膜或氧化钛膜等的反射防止膜15。 Next, as shown in Figure 3-4, the upper surface of the n-type diffusion layer 13 to a uniform thickness to form a silicon oxide film, a silicon nitride film or a titanium oxide film reflection preventing film 15. 例如,在氧化硅膜的情况下,用等离子CVD法以SiH4气体和NH3气体为原材料,在大于等于300℃的加热温度下并在减压下形成反射防止膜15。 For example, in the case where the silicon oxide film by plasma CVD method with SiH4 gas and NH3 gas as a raw material, heating at a temperature of not less than 300 ℃ under reduced pressure and the antireflection film 15 is formed. 折射率例如约为2.0~2.2,反射防止膜15的最佳的膜厚约为70nm~90nm。 E.g., a refractive index of about 2.0 to 2.2, the optimum thickness of the antireflection film 15 is about 70nm ~ 90nm.

接着,使用网板印刷法,在硅衬底11'的背面(与受光面相反的面)的整个面上如图3-5中所示印刷包含玻璃的铝膏并使其干燥,在硅衬底11'的背面的整个面上形成铝膏层17a。 Next, using the screen printing method, the back surface of the silicon substrate 11 '(the surface opposite to the light receiving surface) of the entire surface of the printing as shown in Fig. 3-5 an aluminum paste containing a glass and dried, in the silicon substrate the entire surface of the bottom 11 'of the aluminum paste layer formed on the back surface 17a. 在该铝膏层17a中,与背面银电极19的形成部位对应地设置了开口。 In the aluminum paste layer 17a, the parts forming the back-surface silver electrode 19 are provided corresponding to the openings. 用形成网板掩模的线径、乳剂厚度等可调整铝膏的涂敷厚度。 Forming a stencil mask with a diameter, thickness and other adjustable emulsion coating thickness of aluminum paste.

接着,使用网板印刷法,在形成了铝电极17的硅衬底11'的背面(与受光面相反的面)上如图3-6中所示印刷背面银电极19用银膏并使其干燥,形成银膏层19a。 Next, using the screen printing method, the back surface of the silicon substrate in the formation of the aluminum electrode 17, 11 '(the surface opposite to the light receiving surface receiving) printed on the back-surface silver electrode 19 as shown with the silver paste in Figures 3-6 and allowed to and dried to form a silver paste layer 19a. 此时,如图1-3中所示,使银膏层19a的形状成为将角部作成了圆角部的大致四角形(长方形)。 At this time, as shown in Figure 1-3, so that the shape of the silver paste layer 19a becomes the corner portions become rounded portion as a substantially rectangular (rectangle). 在此,例如,如图3-7和图3-8中所示,可使用对于网格25由乳剂27形成了图案的网板掩模进行银膏的印刷。 Here, for example, as shown in FIG. 3-7 and FIG. 3-8, the grid 25 may be used for the emulsion 27 is formed by a screen mask pattern is printed with silver paste.

再者,使用网板印刷法,在形成了反射防止膜15的硅衬底11'的表面(受光面)上印刷表面银电极21用的银膏并使其干燥,如图3-9中所示,形成银膏层21a。 Furthermore, using the screen printing method, in the formation of the antireflection film 15 of the silicon substrate 11 'of the surface (light receiving surface) of silver paste on the printed surface of the silver electrode 21 and dried by, as shown in Figure 3-9 shown, to form a silver paste layer 21a. 用形成网板掩模的网格的线径、乳剂厚度等也可调整银膏的涂敷厚度。 Forming a stencil mask with mesh diameter, thickness, etc. You can also adjust the emulsion coating thickness of the silver paste.

接着,在用于电极形成的烧结工序中,同时在600℃~900℃下对表面和背面电极用膏层进行几分钟~十几分钟的烧结。 Subsequently, in the sintering step for the electrode formed, while at 600 ℃ ~ 900 ℃ the surface and the back electrode several minutes to ten-odd minutes sintering paste layer. 在硅衬底11'的表面(受光面)一侧,银膏层被烧结,如图3-10中所示,成为表面银电极21,而在反射防止膜15熔融的期间内,银材料通过银膏中包含的玻璃材料与硅衬底11'的硅接触,反射防止膜15再次固化。 In the surface of the silicon substrate 11 '(light receiving surface) side, the silver paste layer is sintered, as shown in Fig. 3-10, to become silver electrode surface 21, the antireflection film 15 is melted during the silver materials by glass material with the silicon substrate included in the silver paste 11 'is in contact with silicon, antireflection film 15 solidified again. 由此来确保表面银电极21与硅的导通。 Thereby ensuring conduction surface silver electrode 21 and silicon. 一般将这样的工艺称为烧透法(fire-through process)。 Such a process generally known as burn through Act (fire-through process).

另一方面,在硅衬底11'的背面(与受光面相反的面)一侧,铝膏层被烧结,如图3-10中所示,成为铝电极17,银膏层被烧结,如图3-10中所示,成为背面银电极19。 On the other hand, the back surface of the silicon substrate 11 '(the surface opposite to the light receiving surface) side, an aluminum paste layer is sintered, as shown in Fig. 3-10, the aluminum electrode 17 becomes, the silver paste layer is sintered, e.g. As shown in Figure 3-10, become back-surface silver electrode 19. 在此,铝膏的铝与硅衬底11'的硅反应,在铝电极17的正下方形成p+层14。 Here, the aluminum paste of aluminum and the silicon substrate 11 'of silicon reaction, p + layer 14 immediately below the aluminum electrode 17 is formed. 一般将该层称为BSF(背面场)层,对太阳能电池的能量变换效率的提高有贡献。 This layer is generally referred to as BSF (back surface field) layer, the energy conversion efficiency of the solar cell to improve contribute. 而且,硅衬底11'中被n型扩散层13和p+层14夹住的区域成为p型层11。 Further, the silicon substrate 11 'is sandwiched between the n-type diffusion layer region 13 and p + layer 14 becomes a p-type layer 11.

此外,在银膏与硅衬底11'直接相接的部位中,直接与硅衬底11'的硅反应,此外,在与铝膏接触的部位中,硅衬底11'的硅、铝膏(铝电极17)的铝、背面银电极19的银这三种金属部分地形成合金。 In addition, in the silicon substrate 11 with the silver paste 'parts in direct contact directly with the silicon substrate 11' of silicon reaction, moreover, in contact with the aluminum paste portion, the silicon substrate 11 'of silicon, aluminum paste (aluminum electrode 17) of aluminum, silver three back-surface silver electrode 19 is formed in part of metal alloy. 利用以上的工序,利用太阳能电池单元制造工艺完成单元。 By the above step, the solar cell manufacturing process completion unit. 再有,在单元制作工序后的模块制作工序中,在该银电极3上配置用于向外部取出输出的铜制的接线。 Further, at the unit manufacturing step after the step of fabricating the module, disposed on the silver electrode 3 for copper wiring to an external lead output.

再有,只通过背面银电极的形状的变更,就可实现上述的太阳能电池单元,不变更已有的设备,只通过背面银电极用的银膏的网板印刷时的掩模形状的变更,就可实现上述的太阳能电池单元。 Further, only by changing the shape of the rear surface silver electrode, can achieve the above-described solar cell, without changing the existing equipment, by only changing the shape of the mask back-surface silver electrode with a silver paste when the stencil printing, can achieve the above-described solar cell.

接着,关于背面银电极的削减面积和银膏的削减量,举出具体的例子来说明。 Then, on the reduction of the area and reduce the amount of silver paste on the back of a silver electrode, specific examples to illustrate. 在此,如图4-1和图4-2中所示,以按以下的条件构成了在纵方向上以2列排列了相邻的背面银电极19的太阳能电池单元的情况为例来说明。 Here, as shown in FIG. 4-1 and FIG. 4-2, the situation under the following conditions to form the in the longitudinal direction are arranged adjacent to two silver electrodes of the solar cell rear surface 19 of example to illustrate the .

·背面银电极19的长边长度L1=9.8mm·背面银电极19的短边长度L5=7.8mm·背面银电极列间的距离L9=75mm·背面银电极列中的两端的背面银电极19间的距离L11=135mm·背面银电极列中相邻的背面银电极19间的距离L13=22.5mm在表1中表示在上述那样的尺寸的太阳能电池单元中在使背面银电极19的圆角部的曲率半径R以0.5mm的间距从1.0mm至3.0mm变化时的背面银电极19的削减面积和银膏削减率。 The back of the silver electrode 19 on the back of a silver electrode distance · 19 long side length L1 = 9.8mm · length of the short side of the back of the silver electrode 19 L5 = 7.8mm · back of the silver electrode between columns L9 = 75mm · back of the silver electrode column ends distance between L11 = 135mm · back-surface silver electrode column adjacent back-surface silver electrodes 19 of L13 = 22.5mm in Table 1 shows the size of the above-described solar battery cells in the back silver electrode 19 of the fillet portion with the radius of curvature R of 0.5mm pitch from 1.0mm to 3.0mm rear surface silver electrode 19 changes when the area reduction rate and the reduction of silver paste.

〔表1〕 [Table 1]

如在表1中所示,随着使背面银电极19的圆角部的曲率半径R从1.0mm至3.0mm变大,背面银电极19的削减面积(mm2)从0.9mm2增加到7.7mm2。 As shown in Table 1, with the back-surface silver electrode 19 so that the radius of curvature R of the round portion is increased from 1.0mm to 3.0mm, back-surface silver electrode cutting area (mm2) 19 from 0.9mm2 to 7.7mm2. 而且,银膏削减率(%)、即银膏的削减效果从1.1%增加到10.1%。 Moreover, silver paste reduction rate (%), the effect of reducing the silver paste from 1.1% to 10.1%. 由此,通过应用本发明,可削减背面银电极19用的银膏量,在与本实施形态有关的太阳能电池单元中可谋求材料费的削减,可以说能实现廉价的太阳能电池单元。 Thus, by applying the present invention, the amount of silver paste can be reduced back-surface silver electrode 19 with, in the present embodiment in the solar cell may seek to cut material costs, it can be said to achieve an inexpensive solar cell.

实施形态2. Embodiment 2.

在实施形态2中,说明与本发明有关的太阳能电池单元的另一形态。 In Embodiment 2, illustrating another form of the present invention relating to the solar cell. 与实施形态2有关的太阳能电池单元的基本的结构与上述的与实施形态1有关的太阳能电池单元是同样的。 Embodiment 2 The basic structure of the solar cell with the above-described Embodiment 1 related to the solar cell is the same. 因而,在以下只说明与实施形态2有关的太阳能电池单元和与实施形态1有关的太阳能电池单元的不同点。 Thus, in the following only the differences will be described with Embodiment 2 of the solar cell and a first embodiment related to the solar cell. 在以下的附图中,对于与实施形态1有关的太阳能电池单元同样的构件附以与实施形态1相同的符号。 In the following drawings, parts with the first embodiment relating to the same member of the solar cell with the same reference numerals as Embodiment 1.

图5-1~图5-3表示与本发明的实施形态2有关的太阳能电池单元的示意结构,图5-1与图1-3对应,是表示与实施形态2有关的太阳能电池单元的背面一侧(与受光面相反的面一侧)的示意结构的平面图。 Figure 5-1 to Figure 5-3 shows the embodiment 2 of the invention related to a schematic structure of the solar cell, corresponding to Figure 5-1 and Figure 1-3, which shows the back of the second embodiment related to the solar cell side (opposite to the light receiving surface side and receiving side) plan view showing a schematic structure. 此外,图5-2与图1-4对应,放大地表示图5-1的平面图中的背面银电极31的周边,放大地表示在太阳能电池单元的背面上设置的铝电极17与背面银电极31部分地交叠的部分。 Furthermore, Figure 5-2 and Figure 1-4 corresponding, enlarged plan view showing the periphery of FIG. 5-1 back-surface silver electrode 31, an enlarged scale, the aluminum electrode on the back surface of the solar cell 17 provided with the back-surface silver electrode 31 partially overlapping portions.

而且,图5-3与图1-5对应,放大地表示背面银电极31的周边,是放大地表示在太阳能电池单元的背面上设置的铝电极17和背面银电极31部分地交叠的区域D和区域E的周边部的剖面图。 Furthermore, Figure 5-3 and Figure 1-5, magnification showing the surrounding back-surface silver electrode 31, is an enlarged and the back-surface silver electrode 31 partially overlapping area of the aluminum electrode 17 on the back surface of the solar cell disposed sectional view of a peripheral portion of the D and E regions. 由于与实施形态1有关的太阳能电池单元的剖面结构和太阳能电池单元的受光面一侧(表面一侧)的示意结构与实施形态1的情况是同样的,故可参照图1-1和图1-2。 As with the first embodiment relating to a cross-sectional structure of a solar cell and a solar cell light-receiving surface side (surface side) in the case of a schematic structure of Embodiment 1 is the same, it can refer to Figure 1-1 and Figure 1 -2.

在此,本实施形态中的背面银电极31与实施形态1中的背面银电极19对应,如图5-1和图5-2中所示,在将角部作成了倒角部而不是作成圆角部这一点上与实施形态1的情况不同。 In this, the present embodiment of the back-surface silver electrode 31 in Embodiment 1 corresponding back-surface silver electrode 19, as shown in FIG. 5-2 and 5-1, at the corner portions as would be made instead of the chamfered portion This round portion on the case of Embodiment 1 is different.

在此,在与本实施形态有关的太阳能电池单元中,如图5-1和图5-2中所示,背面银电极31在硅衬底的面内方向上呈大致四角形(长方形)。 Here, in the present embodiment in the solar cell, as shown in Figure 5-2 and 5-1, back-surface silver electrodes 31 in the in-plane direction of the silicon substrate has a substantially rectangular (rectangle). 而且,将背面银电极31的大致四角形(长方形)的角部作成了倒角部。 Moreover, the back-surface silver electrode is substantially rectangular (rectangular) as the corner portion 31 become a chamfered portion.

而且,虽然背面银电极的角部的形状与实施形态1的情况不同,但在铝电极17和背面银电极31部分地交叠的区域D和区域E中,使硅衬底的p+层14的硅、铝电极17的铝、背面银电极31的银这三种金属部分地合金化,如图5-2和图5-3中所示,形成了合金部33。 Moreover, although the shape of the corner portion of the embodiment of the case of a back-surface silver electrode is different, but in the back-surface silver electrodes 31 and 17 partially overlap region D and the region E aluminum electrode, the p + silicon substrate layer 14 silicon, aluminum, aluminum electrodes 17, 31 of the back-surface silver electrode silver three alloying metal part, as shown in FIG. 5-2 and FIG. 5-3, the alloy portion 33 is formed. 再有,在图5-3中,对于区域D和区域E,各金属(硅、铝、银)的边界是清晰的,但由于该部分部分地被合金化,故实际上当然是不清晰的。 Further, in Figure 5-3, for the area D and area E, each metal (silicon, aluminum, silver) is a clear boundary, but because this portion is partially alloyed, in fact, of course it is not clear .

由此,在与本实施形态有关的太阳能电池单元中,如图5-3中所示,在铝电极17和背面银电极31部分地交叠的区域D和区域E中可靠地形成合金部33,即使在背面银电极31的端部中,也可靠地键合了背面银电极31与铝电极17。 Accordingly, in the present embodiment in the solar cell, as shown in Fig. 5-3, 17 and back-surface silver electrode 31 partially overlapping the region D and the region E aluminum alloy electrode portion 33 is reliably formed , even in the back-surface silver electrode 31 in the end portion, also securely bonded to the back-surface silver electrode 31 and aluminum electrode 17.

在与本实施形态有关的太阳能电池单元中,为了消除背面银电极31的锐利的角部而将角部作成了倒角部,以免应力集中于背面银电极31的角部。 In this embodiment of the solar cell, in order to eliminate the sharp corner portion of the back-surface silver electrode 31 and the chamfered corner portions become portions as to avoid stress concentration on the corner portion 31 of the back-surface silver electrode. 由此,在与本实施形态有关的太阳能电池单元中,可缓和集中于背面银电极31的角部的应力,如图5-3中所示,在铝电极17和背面银电极31部分地交叠的区域D和区域E中可靠地形成合金部33,提高了铝电极17与背面银电极31间的键合力、铝电极1 7和背面银电极31的衬底键合力。 Accordingly, in the present embodiment in the solar cell, will ease the stress concentrated on the corner portion of the back-surface silver electrode 31, as shown in Fig. 5-3, 17 and back-surface silver electrode aluminum electrode 31 is partially cross- Alloy 33 overlapping areas D and E in the region reliably formed to improve the aluminum electrode 17 and the key 31 back silver electrode force, aluminum electrode substrate keys 17 and 31 on the back of a silver electrode force. 因而,按照与本实施形态有关的太阳能电池单元,起到即使在背面银电极19的角部中也可靠地键合背面银电极19与铝电极17从而可实现有效地防止了背面银电极19的剥离的太阳能电池单元的效果。 Thus, in accordance with this embodiment of the solar cell, even when played back-surface silver electrode at the corner portion 19 is also securely bonded to the aluminum back-surface silver electrode 19 and the electrode 17 which allows for effectively preventing the back-surface silver electrode 19 effect peeling of the solar cell.

在倒角尺寸C比合金部33的尺寸大的情况下,不能部分地形成铝电极17与背面银电极31的合金部,作为背面银电极31是不适当的。 In the C chamfer dimension larger than the size of the alloy portion 33 of the case, can not be partially formed alloy portions 17 and back-surface silver electrode 31 aluminum electrode, as the back-surface silver electrode 31 is inappropriate. 因而,如图5-2中所示,有必要以能可靠地形成合金部33的方式来决定合金部33的尺寸的铝电极17和背面银电极31在背面银电极31的长边方向上交叠的部分的尺寸L21、L23和铝电极1 7和背面银电极31在背面银电极31的短边方向上交叠的部分的尺寸L25、L27的值。 Thus, as shown in Figure 5-2, it is necessary to be able to reliably manner alloy portion 33 is formed to determine the size of the aluminum electrode 17 and the alloy portion 33 of the back-surface silver electrode 31 at the back of the hand over the longitudinal direction of silver electrode 31 L21 size of the portion of the stack, and the size of the portion L25 L23 aluminum electrode 17 and the back-surface silver electrode 31 on the short side direction of back-surface silver electrode 31 overlap, the value of L27. 另外,如后述那样利用网板印刷形成铝电极17和背面银电极31,也应考虑铝膏和银膏的印刷时的位置偏移来决定上述尺寸。 Further, as described later are formed by screen printing the aluminum electrode 17 and the back-surface silver electrode 31, should also consider the location of the offset printing an aluminum paste and silver paste to determine the time of the above dimensions.

此外,在与本实施形态有关的太阳能电池单元中,也如上所述,可使铝电极17与背面银电极31间的键合、铝电极17和背面银电极31的与衬底的键合变得可靠。 Further, in the present embodiment in the solar cell, it is also described above, the aluminum electrode 17 and the back can silver electrode bonding 31, the aluminum electrode 17 and the back-surface silver electrode substrate together with the bond becomes 31 was reliable. 因而,在与本实施形态有关的太阳能电池单元中,也起到下述的效果:即使在为了降低太阳能电池单元的成本而减薄硅衬底的情况下,也没有像现有技术那样在硅衬底中产生多个衬底裂纹的情况,可充分地予以对应,可增加可使用的银膏种类的选择自由度。 Thus, in the present embodiment in the solar cell, and also play the following effect: even in the case in order to reduce the cost of the solar cell and the thinning of the silicon substrate, as there is no prior art in silicon generating a plurality of substrates in the case of the substrate cracks, can be sufficiently correspond, the silver paste may be used to increase the freedom of choice of the kind.

再者,在与本实施形态有关的太阳能电池单元中,由于将在现有的太阳能电池单元的背面银电极中理应存在的锐利的角部作成倒角部,故也使背面银电极的面积变小,削减了在背面银电极31中使用的银膏的量。 Furthermore, in the present embodiment in the solar cell, since the sharp corners at the back of the conventional silver electrode of the solar cell should be made present in the chamfered portion, it is also so that the area of back-surface silver electrode becomes small, reducing the amount used in the 31 back of the silver electrode silver paste. 因而,在与本实施形态有关的太阳能电池单元,也起到可谋求材料费的削减、可实现廉价的太阳能电池单元这样的效果。 Thus, in the present embodiment in the solar cell, may also play a seek material cost reduction, such an effect can be achieved cheap solar cell.

再有,除了在对银膏层进行网板印刷时如图5-1中所示将角部作成了倒角部的大致四角形(长方形)以外,可用与实施形态1的情况同样的工序制作与本实施形态有关的太阳能电池单元。 Further, at the time of addition to the silver paste layer by screen printing in the corner portion as shown in Figure 5-1 would be substantially rectangular chamfered portion (rectangular) as shown, can be used in Embodiment 1 was used and the production process For a solar cell morphology of the present embodiment. 而且,也只通过背面银电极的形状的变更,就可实现与本实施形态有关的太阳能电池单元,不变更已有的设备,只通过变更在网板印刷背面银电极用的银膏时所使用的掩模形状,就可实现上述的太阳能电池单元。 Moreover, only by changing the shape of the rear surface silver electrode, can be achieved with this embodiment of the solar cell, without changing the existing equipment, by only changing when the silver paste screen printing on the back of the silver electrode to be used The mask shape can achieve the above-described solar cell.

接着,关于背面银电极的削减面积和银膏的削减量,举出具体的例子来说明。 Then, on the reduction of the area and reduce the amount of silver paste on the back of a silver electrode, specific examples to illustrate. 在此,如图6-1和图6-2中所示,以按以下的条件构成了在纵方向上以2列排列了相邻的背面银电极31的太阳能电池单元的情况为例来说明。 Here, as shown in Figure 6-1 and Figure 6-2, a case in the longitudinal direction are arranged in two adjacent back-surface silver electrodes of the solar cell 31 under the following conditions constitutes an example to illustrate .

·背面银电极31的长边长度L21=9.8mm·背面银电极31的短边长度L25=7.8mm·背面银电极列间的距离L9=75mm·背面银电极列中的两端的背面银电极31间的距离L11=135mm·背面银电极列中相邻的背面银电极31间的距离L13=22.5mm在表2中表示在上述那样的尺寸的太阳能电池单元中在使背面银电极31的倒角部的倒角尺寸C以0.5mm的间距从1.0mm至3.0mm变化时的背面银电极31的削减面积和银膏削减率。 • The length of the long side of the back of the silver electrode 31 L21 = 9.8mm · length of the short side of the back of the silver electrode 31 L25 = 7.8mm · distance between the back of the silver electrode column L9 = 75mm · the back row of the back silver electrode silver electrode ends 31 distance between L11 = 135mm · back-surface silver electrode column adjacent back-surface silver electrode 31 of L13 = 22.5mm are shown in Table 2. In the above-described dimensions of the solar battery cells 31 in the back silver electrode chamfers Department C chamfer dimension to 0.5mm pitch from 1.0mm to 3.0mm on the back of the silver electrode 31 changes reduce the area and reduce the rate of silver paste.

〔表2〕 [Table 2]

如在表2中所示,随着使背面银电极31的倒角部的倒角尺寸C从1.0mm至3.0mm变大,背面银电极31的削减面积(mm2)从2.0 mm2增加到18.0mm2。 As shown in Table 2, with the back-surface silver electrode 31 so that the chamfered portion of the chamfer dimension C becomes larger from 1.0mm to 3.0mm, back-surface silver electrode 31 cut area (mm2) from 2.0 mm2 to 18.0mm2 . 而且,银膏削减率(%)、即银膏的削减效果从2.6%增加到23.5%。 Moreover, silver paste reduction rate (%), the effect of reducing the silver paste from 2.6% to 23.5%. 由此,通过应用本发明,可削减背面银电极31用的银膏量,在与本实施形态有关的太阳能电池单元中可谋求材料费的削减,可以说能实现廉价的太阳能电池单元。 Thus, by applying the present invention, the amount of silver paste can be reduced back-surface silver electrode 31 with, in the present embodiment in the solar cell may seek to cut material costs, it can be said to achieve an inexpensive solar cell.

再有,在实施形态1和实施形态2的任一情况下,为了得到更大的银膏的削减效果,有必要将曲率半径或倒角尺寸取得较大,但如果取得过大,则不能形成铝与银的合金部。 Further, in Embodiment 1 and Embodiment 2 either case, in order to obtain a greater effect of reducing the silver paste, it is necessary to obtain the curvature radius or chamfer size is larger, but if made too large, can not be formed the portion of the aluminum alloy and silver. 在实际选定曲率半径或倒角尺寸时,有必要考虑在印刷铝电极和银电极用的膏时所产生的位置偏移,有必要以能可靠地形成合金部的方式来决定曲率半径和倒角尺寸。 When the actual size of the selected radius of curvature or chamfered, it is necessary to consider the location of offset printing with an aluminum electrode and a silver electrode paste produced, it is necessary to fashion alloy portion can be reliably formed to determine the radius of curvature and pour angular size.

此外,与上述实施形态1和实施形态2有关的太阳能电池单元是本发明的实施形态的一例,本发明不由上述的记述来限定,在不脱离本发明的要旨的范围内,可适当地变更。 In addition, the above-described first embodiment and the second embodiment related to the solar cell embodiment of the present invention is an example, the present invention is defined not by the above description, without departing from the scope of the gist of the present invention, may be appropriately changed.

产业上的可利用性如上所述,与本发明有关的太阳能电池单元对于铝电极与取出输出用的银电极部分地互相交叠的结构的太阳能电池单元是有用的。 INDUSTRIAL APPLICABILITY As described above, the solar cell of the present invention pertains to an aluminum electrode and a silver electrode output taken partially overlap each solar cell structure is useful.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
CN101981704B25 Mar 200927 Mar 2013夏普株式会社Solar cell, solar cell string and solar cell module
CN102017173B12 May 200924 Apr 2013株式会社爱发科Thin film solar battery module and method for manufacturing the same
Classifications
International ClassificationH01L31/0224
Cooperative ClassificationH01L31/022425, Y02E10/50, H01L31/0504
European ClassificationH01L31/0224B2, H01L31/0224B2B
Legal Events
DateCodeEventDescription
12 Dec 2007C06Publication
6 Feb 2008C10Request of examination as to substance
15 Aug 2008REGReference to a national code
Ref country code: HK
Ref legal event code: DE
Ref document number: 1111807
Country of ref document: HK
6 Jul 2011C14Granted
25 Nov 2011REGReference to a national code
Ref legal event code: GR
Ref country code: HK
Ref document number: 1111807
Country of ref document: HK