201133510 六、發明說明： 【發明所屬之技術領域】 本發明係關於-種太陽電池之背面電極用在呂糊。 【先前技術】 ,通常結晶矽太陽電池係使用一種厚180〜220微米之p_ ，矽基板。在P_型石夕基板之前表面上形成厚0.2〜0.6微米之 ，而且在Ν·型雜質層上循序地形成抗反射用 ^層與前面電極。此外在ρ柳基板之背表面上形成紹 私極。此铭電極係藉由使用網版印刷等塗佈紹糊，將塗佈 =糊乾燥，然後在低溫(約_。〇及高溫_〜95〇。〇二段 ，結已乾燥之雜而職。在此錢結程料 ^ Ρ-型石夕基板中而形成A1_Si合金層。此偏合金層形^ ^場⑽F)層續止由太陽電池產生之電子重組，及改良 太陽電池產生之載體的收集效率。太陽電池之效率受 陽 與均勻性影響。即在減小咖層之厚度時太 W池之效率降低，及在增加其厚度時其效率增加。 同時為了降低太陽電池之縣，近紅減抑晶圓之 在過度地減抑晶圓之厚度時，以日圓由於石夕 曰曰囡與鋁間之熱膨脹係數差而弓翹，因而矽晶圓裂開。 雷2乃服以上之問題’其必須減小作為背面電極之紹 妙、而ίίί，及此目的可藉由減少銘糊之塗佈量而完成。 塗佈較少量之紹糊時跡廣(其為背面電場層)之厚 太陽電池之效率退化，及在共燒結程序期間 t極層中逐漸地形賴球及/或凸塊。在此情形，在電極 曰中形成之㈣及/或凸塊降低㈣圓之背表面的平坦性， 而且應力針在這些㈣及/或凸虹，因而在太陽電池製 4/16 201133510 程或太陽電池模組製程期間造成太陽電池破裂。 之链ί $驗在共燒結程序_形成較少 3二 提議如下:韓國專利登記第1◦姻580 I不種銘糊，其係包括粒度為〇 5〜1〇微米 機媒液、及金屬炫氧化物；韓國未審查專利申靖安I門第 10-2008-0068638铗姐-土 寸明木公開第 Μ之胁’其係包括粒度為2〜20 有機職'及金额氧化物；韓國未 番查專利^案公開第職Q8⑻572 粒度為2〜20微米之歸、玻料、 !譲心二：二國一未審查專利申請案公開第 η乎之A:㈣—馳糊’其係包絲度為4〜10 性破料、乙氧㈣、乙氧化鈦、及發煙石夕 糊均;二玻料與有機媒液，以上專利文件揭示之鋁 、杳於》、或無機添加劑。然而這些添加劑因為其如殘 子^或者在_共燒結程序期間成孔，使得銘糊之 效率：、此:::低而成問題，因而不良地影響太陽電池之 声佶 之匈賴為紹粉具有1()〜2g微米之最大粒 八中形成之孔而可能形成鋁凸塊。 L發明内容】 及本:====上先前技藝發生之問題而完成’ 電流㈣與斷路電:二:生 -r 5/16 201133510 之效率。 為了完成以上之目的，本發明之一個實施形態提供— 種太陽電池之背面電極用鋁糊，其係包括：鋁粉，其中 將平均粒度（Dm)為4〜6微米之铭粉、與平均粒度（d5 ) 為2〜4微米之铭粉以&4〜9·5:0·5重量比之比例 本發明之另一個實施形態提供一種製造太陽電池之方 法，其係包括使用此鋁糊形成背面電極之程序。 依照本發明之铭糊由於使用二或更多種平均粒产 不同之鋁粉來改良鋁糊與紋理化矽晶圓間之接觸，而在= 燒結程序期間可防止太陽電池弓翹且可使鋁球及/或凸塊之 形成以及變黃之發生最小化，可大幅增加短路電流㈣與斷 路電壓(Voc)之值，及可明顯地改良太陽電池之效率。 【實施方式】 本發明提供一種太陽電池之背面電極用鋁糊，其係包 括：鋁粉，其中將D5〇=4〜6微米之在呂粉、與D5〇=2〜4 微米之叙粉以6:4〜9.5:0.5重量比之比例混合。 在此’’Dm”表示鋁粉之平均粒度。 通常為了放大接收太陽光之面積而财域電池之前 後表面紋理化。通常單晶碎晶圓係以金字塔之形式纹理 化’而且此金字塔具有2〜丨5微米之高度及2〜2()微来之寬 度。相反地圓係以不規則迷陣之形式紋理化。 將紋理化H在其背表面上藉網版印刷、凹版印刷或平 板印刷塗覆論，錢’然後共燒結形成料&在此程 =田IS粒子之大小過大時’ ！g糊不易接觸⑪晶圓 此在印刷及乾燥後於織財晶圓之 隙。在共燒結程序期間，凹節通過_層==: 6/16 201133510 表面’而附帶I呂球及/或凸塊之發生。 然而本發明人發現，在使用具有單一粒度分布之鋁粉 時，即使粒度小仍無法以鋁粉輕易地充填間隙，而在使用 二或更多種平均粒度不同之鋁粉時可使間隙之形成最 小化。 …个如Θ之太Μ %〜〜月囬龟極用鋁糊包 括：鋁粉，其中將D5〇=4〜6微米之鋁粉、與D5〇=2〜4 微米之鋁粉以6:4〜9.5:0.5重量比之比例混合。 *在使用平均粒度分布偏離以上範圍之⑽製備雜 守’紹糊不能深人轉人紋理化⑦晶圓巾，而且純中之 亦增加。目此切^上紐__成背表面場 3 ’紹電極之電岐有變低，及無法防切晶圓弓想。 日士 在使用具有此平均粒度分布之紹粉製備紹糊 ^亦^深场滲人紋理切㈣巾，而域财之孔隙 ^電極之f因此麵晶圓上均句地形成背表面場(BSF)層， 二且變，、，及防止石夕晶圓弓-。因此在使用以此 增加，而且^糊製造太陽電池時’太陽電池之短路電流值 因在轉a ^率亦增加。此相此方式製造之太陽電池 序後可防止於ls電極中發生之變黃而有利。 按编量提供—種太陽電池之背面電極賴糊，其 二〜75重量%之㈣，其中將 6:4〜9 5.0 5會、旦 ^ 與D5〇=2〜4微米之鋁粉以 糊所括,75重量%之量的•柿 _s 低於65重量％時，具有在煅燒程序後印 7/16 201133510 刷之銘層變薄的問題’使得未充分地形成背表面場(BSF) 層’因而增加太陽電池之效率。此外在其中所包括銘粉之 量大於75重量％時’其有印刷之鋁層過厚，因而造成石夕晶 圓弓翹的問題。 本發明之鋁糊係可包括0.01〜5重量％，較佳為〇.〇5〜3 重量％，更佳為0.1〜1重量％之量的玻料。在玻料之量小於 0.01重量％時，其有矽晶圓易弓翹，及鋁糊與矽晶圓間之黏 附性降低的問通。此外在其量大於5重量％時，其有電阻變 南’因此降低太陽電池之效率的問題。 玻料可為Bi2〇3-Si〇2-Al2〇rB2〇3-SrO。玻料可包括但不201133510 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a back electrode for a solar cell. [Prior Art] Generally, a crystalline germanium solar cell system uses a p_, germanium substrate having a thickness of 180 to 220 μm. An anti-reflection layer and a front electrode are sequentially formed on the surface of the P-type stone substrate with a thickness of 0.2 to 0.6 μm. In addition, a private pole is formed on the back surface of the pliu substrate. The electrode is coated by using a screen printing method, etc., and the coating is dried, and then dried at a low temperature (about _. 〇 and high temperature _~95 〇. 〇 second section, the knot has been dried. The A1_Si alloy layer is formed in the carbon-based material of the 结-type stone substrate. The partial alloy layer shape (10)F) layer continues the electron recombination generated by the solar cell, and the carrier of the modified solar cell is collected. effectiveness. The efficiency of solar cells is affected by yang and uniformity. That is, the efficiency of the W pool is lowered when the thickness of the coffee layer is reduced, and the efficiency is increased when the thickness thereof is increased. At the same time, in order to reduce the solar cell count, the near-red reduction wafer is excessively reducing the thickness of the wafer, and the yen is cracked due to the difference in thermal expansion coefficient between the stone and the aluminum. open. Ray 2 is the problem of the above. It must be reduced as a back electrode, and the purpose can be achieved by reducing the amount of coating. The thickness of the solar cell is degraded by coating a relatively small amount of the paste (which is the back electric field layer), and the balls and/or bumps are gradually formed in the t-layer during the co-sintering process. In this case, the (4) and/or the bumps formed in the electrode turns lower the flatness of the back surface of the circle (4), and the stress needles are in these (four) and/or convex rainbows, thus in the solar cell system 4/16 201133510 or the sun The solar cell is broken during the battery module process. The chain ί $ in the co-sintering process _ formation less 3 two proposals as follows: Korean patent registration 1st marriage 580 I not a kind of paste, which includes particle size of 〇5~1〇 micron machine liquid, and metal dazzle Oxide; Korean unexamined patent Shen Jingan I door 10th-2008-0068638 铗 sister- soil inch Mingmu public Μ Μ ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ^ The case of the open position Q8 (8) 572 particle size of 2 ~ 20 microns of the return, glass, 譲 heart two: two countries an unexamined patent application disclosure of the first arbitrarily A: (four) - 糊 ' ' 其 其 其 其 其~10 Severe materials, ethoxy (tetra), TiO 2 , and smoulder paste; two glass materials and organic media, the above patent documents disclose aluminum, bismuth, or inorganic additives. However, these additives are made into pores because they are, for example, remnant or during the co-sintering process, so that the efficiency of the paste::::: is a problem, thus adversely affecting the sound of the solar cell. An aperture formed in the largest particle of 1 () to 2 g of micron may form an aluminum bump. L invention content] and this: ==== on the previous technical problems and completed 'current (four) and open circuit: two: raw -r 5/16 201133510 efficiency. In order to accomplish the above object, an embodiment of the present invention provides an aluminum paste for a back electrode of a solar cell, which comprises: aluminum powder, wherein the average particle size (Dm) is 4 to 6 μm of the powder, and the average particle size (d5) A powder of 2 to 4 μm in a ratio of & 4 to 9·5:0·5 by weight ratio. Another embodiment of the present invention provides a method of producing a solar cell, which comprises forming the aluminum paste. The procedure for the back electrode. The paste according to the present invention improves the contact between the aluminum paste and the textured tantalum wafer by using two or more aluminum powders of different average grain yields, and prevents the solar cell from being bent and can be made aluminum during the sintering process. The formation of balls and/or bumps and the occurrence of yellowing are minimized, which greatly increases the values of short-circuit current (4) and open circuit voltage (Voc), and can significantly improve the efficiency of solar cells. [Embodiment] The present invention provides an aluminum paste for a back electrode of a solar cell, which comprises: aluminum powder, wherein D5〇=4~6 μm in Lu powder, and D5〇=2~4 micron in the powder 6:4 to 9.5: 0.5 by weight ratio of the mixture. Here, ''Dm' indicates the average particle size of the aluminum powder. Usually the surface of the front surface of the financial domain is textured in order to amplify the area of the received sunlight. Usually the single crystal chip is textured in the form of a pyramid' and this pyramid has 2 ~ 丨 5 microns height and 2 to 2 () micro width. Conversely the circle is textured in the form of irregular puzzles. Textured H borrows screen printing, gravure or lithography on its back surface Coating theory, money 'then co-sintering material & in this process = the size of the field IS particles is too large '!g paste is not easy to contact 11 wafers after printing and drying in the gap of the weaving wafer. In the co-sintering During the procedure, the concave section passes through the _ layer ==: 6/16 201133510 surface 'with the occurrence of I Lu balls and/or bumps. However, the inventors have found that even when the aluminum powder having a single particle size distribution is used, the particle size is small. It is still not possible to easily fill the gap with aluminum powder, and the formation of the gap can be minimized when two or more aluminum powders having different average particle sizes are used. Including: aluminum powder, which will be D5〇=4~6 microns The aluminum powder and the aluminum powder of D5〇=2~4 micrometers are mixed in a ratio of 6:4 to 9.5:0.5 by weight. *In the use of the average particle size distribution deviating from the above range (10), the preparation of the miscellaneous 'success can not be deep People are textured 7 wafers, and the purity is also increased. The purpose of this is to cut the new __ into the back surface field 3 'the electrode of the electrode has become lower, and can not prevent the cutting of the wafer bow. Using the powder with this average particle size distribution to prepare the paste, and also the deep field infiltration of the texture (four) towel, and the surface of the pores of the surface of the electrode, so that the back surface field (BSF) layer is formed on the wafer. Second, change, and, and prevent the Shixi wafer bow - so the use of this increase, and ^ paste manufacturing solar cells 'the solar cell short-circuit current value also increased due to the transfer rate. This phase is manufactured The solar cell sequence can prevent the yellowing which occurs in the ls electrode and is favorable. According to the amount of the solar cell, the back electrode of the solar cell is affixed, which is ～75 wt% (4), which will be 6:4~9 5.0 5 Will, Dan ^ and D5 〇 = 2 ~ 4 microns of aluminum powder is included in the paste, 75% by weight of the persimmon _s less than 65% by weight, After the calcination process, the problem of thinning the inscription layer of the brush 7/16 201133510 is such that the back surface field (BSF) layer is not sufficiently formed, thus increasing the efficiency of the solar cell. In addition, the amount of the powder contained therein is greater than 75 weight. When % is used, the printed aluminum layer is too thick, which causes the problem of the stone wafer. The aluminum paste of the present invention may comprise 0.01 to 5% by weight, preferably 〇. 〇 5 to 3% by weight, more Preferably, the glass material is 0.1 to 1% by weight. When the amount of the glass material is less than 0.01% by weight, the enamel wafer is easy to bow, and the adhesion between the aluminum paste and the ruthenium wafer is lowered. When the amount thereof is more than 5% by weight, there is a problem that the electric resistance becomes south, thus reducing the efficiency of the solar cell. The glass material may be Bi2〇3-Si〇2-Al2〇rB2〇3-SrO. Glass can include but not
莫耳％之Si〇2、i〜ίο莫耳％之Sr0、與2〇〜4〇莫耳％之Be〗。 在玻料中有效地使用SrO以降低玻料之軟化點。在破 料不包括SrO日f，玻料之軟化點提高，使得在燒結太陽電 池期間雜軟化不足’結果紹糊與⑪晶圓間之黏附性降 低’因而降低太陽電池之效率。然而在玻料包括過量之⑽ 時，玻料之軟化點過低，而在鋁電極中生成凸塊。Moer% of Si〇2, i~ίο Moer% of Sr0, and 2〇~4〇 Moer% of Be. SrO is effectively used in the glass to reduce the softening point of the glass. In the case where the material does not include SrO day f, the softening point of the glass material is increased, so that the impurity softening during the sintering of the solar cell is reduced, and the adhesion between the wafer and the 11 wafer is lowered, thereby reducing the efficiency of the solar cell. However, when the glass material includes an excess of (10), the softening point of the glass material is too low, and bumps are formed in the aluminum electrode.
此外用於本發明之玻料可具有_〜6〇(rc之敕化點。在 幾媒液之量低於2G重量％時，具有紹 因此降低鋁糊之印刷性的問題。此外 8/16 201133510 因吩關降低， 如果合 用於太欲叫 傲潤劑、添加劑等。 用於本發明之有機 或更多之有機溶劑、及】2S 里抽可包括75重量％ 媒液係可進-步包括 之聚合物樹脂。又有機 1〜1〇重量％之添加劑。或更少之濕潤劑與搖變劑、及 有機溶劑可具有15G〜WC之沸點，使得其可防 之流動力。常用有機溶劑之實施例可包括 二醇二丙二醇正·二丙二 醇•二二乙二 己基醚、三乙二二 醇己細、乙二醇· 丁基_、乙4土峡、二乙二醇乙基峻、三乙二醇正 取人乙—知本基醚、萜品醇、Texanol®、乙二醇等。 醇二合物樹脂之實施例可包括聚乙烯轉規酮、聚乙烯 ί。;^一醉、乙基纖維素、松脂、酚樹脂、丙烯酸樹脂 較隹&物之量按有機媒液之總量計係可為1〜25重量％， |呂才為5 25重量°/q。在聚合物樹脂之量小於1重量％時， 目之印刷性與分散安定性退化。此外其量高於25重量％ 、J無法印刷鋁糊。 麵rt至於搖交劑與濕潤劑，可使用常用於相關領域之搖變 β人濕潤劑而無限制。 劑，^加劏可為常用於相關領域之分散劑等。作為分散 二使可使用市售界面活性劑，而且其可獨立地或彼此纪合 用。界面活性劑之實施例係可包括：非離子性界面活 201133510 性劑，如醚（包括炫基聚氧乙婦醚、院芳基聚氧乙烯醚、聚 氧乙烯-聚氧丙烯共聚物等）、酯-醚（包括甘油酯之聚氧乙烯 醚、山梨醇酐酯之聚氧乙烯醚、山梨醇酯之聚氧乙烯醚等）、 酯（包括聚乙二醇脂肪酸酯、甘油酯、山梨醇酐酯、丙二醇 酯、糖酯、烷基聚葡萄糖苷等）、及含氮界面活性劑（包括脂 肪酸烷醇醯胺、聚氧乙烯脂肪酸醯胺、聚氧乙烯烷基胺、 胺氧化物等）；及聚合界面活性劑，如聚乙烯醚 '聚乙烯吡 咯烷酮、聚丙烯酸、聚丙烯酸-順丁烯二酸共聚物、聚-12-經基硬脂酸等。 市售界面活性劑產品之實施例可包括hypermer KD(由 Uniqema Corp·製造）、AKM 0531 (由 NOF Corp.製造）、KP(由 Shinetsu Kagaku Kogyo Corp.製造）、POLYFLOW(由 Kyoei Kagaku Corp·製造）、EFTOP(由 Tokemu Products Corp.製 造）、Asahi guard、Surflon(由 Asahi Glass Corp.製造）、 SOLSPERSE(由 Geneka Corp.製造）、EFKA(由 EFKA Chemicals Co” Ltd.製造）、PB 821(由 Ajinomoto Co.，Inc.製 造）、BYK-184、BYK· 185、BYK-2160、Anti-Terra U(由 BYK Corp.製造)等。 分散劑之量按有機媒液之總量計係可為1〜l〇重量％ , 較佳為1〜5重量％。 依照本發明之鋁糊可使用同時自動及公轉之行星式混 合器而容易地製備。即此鋁糊可藉由將上述成分按對應組 成比例置於行星式混合器中，然後攪拌使固體在有機媒液 中適當地混合及分散而製備。在25。〇使用Brookfield HBDV-III Ultra Rheometer 或心軸 CpE_52 測量.其黏度時，. 以此方式製備之鋁糊在5卬111具有20,000〜200,000卬5之黏 10/16 201133510 =。輪乜為可製備鋁糊使得其具有4〇,〇〇〇〜1〇〇,〇〇0()恥之黏 传用ίΓ本發服供—種製造太陽電狀方法，其係包括 吏用此叙_成背面電極之步驟。 带二t式製造之太陽電池因其不易弓，及在電極層 與斷或凸塊’使得_純路電流㈣ 、包&(VOC)之值，及明顯地改良其效率而有利。 下實以下實施例而更詳細地敘述本發明。然而以 限制。以^=例證本發明，而且本發明之範圍不受其 本發明之範ΐ r"j可由縣此技藝者適#地修改而不背離 實施例1:鋁糊之製備 3重I0/。之〇5〇=4〜ό微米的鋁粉、盥7曹旦 D50=2〜4微米的叙粉(4〜6微米：2 吟、里/〇之 鋁粉總量=70重哥 十9·Η重里比例）， 比例的玻料、·重$%之具有以下表1所示組成 、容於-st心 量％之有機媒液(其係使乙基纖唯♦ 办於-㈣巾财驗歧 ^隹素 用同時自動及公轉之混合器將混合物以：二：後使 拌3分鐘而製備蝴。 職卿之轉迷搜 11/16 «λ 201133510 表1 成分 莫耳％ AI2O3 6.5% SrO 5.5% Bl2〇3 26.0% Β2Ο3 30.0% Si02 32.0% 總共 100% Tg (轉移點） 453 熱膨脹係數(l〇々°C) 77 Tdsp 507 實施例2:鋁糊之製備 以如實施例1之相同方式製備鋁糊，除了加入42重量 %之D5〇=4〜6微米的鋁粉、與28重量％之D5〇=2〜4微米的 鋁粉(4〜6微米：2〜4微米=6:4(重量比例），鋁粉總量=70重 量％)。 實施例3:鋁糊之製備 以如實施例1之相同方式製備鋁糊，除了加入66.5重 量％之D5〇=4〜6微米的鋁粉、與3.5重量％之D5〇=2〜4微米 的鋁粉(4〜6微米：2〜4微米=9.5:0.5(重量比例），鋁粉總量 =70重量％)。 實施例4:鋁糊之製備 以如實施例1之相同方式製備鋁糊，除了加入58.5重 量％之D50=4〜6微米的鋁粉、與6.5重量％之D50=2〜4微米 的鋁粉(4〜6微米：2〜4微米=9:1(重量比例），鋁粉總量=65 重量％)、及34.5重量％之有機媒液。 實施例5:鋁糊之製備 以如實施例1之相同方式製備鋁糊，除了加入67.5重 12/16 201133510 量％之〇5〇=4〜6微米的鋁粉、與7.5重量％之〇5〇=2〜4微米 的|呂粉(4〜6被米，2〜4被米=9:1(重量比例），叙粉總量巧; 重量％)、及24.5重量％之有機媒液。 比較例1:鋁糊之製備 以如實施例1之相同方式製備鋁糊，除了加入35重量 %之〇5〇=4〜6微米的紹粉、與35重量。/。之D5〇:=2〜4微采的 鋁粉(4〜6微米：2〜4微米=5:5(重量比例），鋁粉總量=7〇重 量％)、及29.5重量％之有機媒液。 比較例2:鋁糊之製備 以如實施例1之相同方式製備鋁糊，除了加入7〇重量 %之Ε>5〇=2〜4微来的紹粉、及29.5重量％之有機媒液。 測試例：製造太陽電池及測試其特徵 將大小為156 X 156 ¾米及厚200微米之單晶矽晶圓表 面紋理化’使得金字塔之高度為約4〜6微米，然 紋理化矽晶圓之N-側塗覆SiNx。繼而在矽晶圓之背表^上 印刷匯流排條然後乾燥，然後使用250篩目之網版印刷板 在其上塗佈實施例1至5及比較例丨至2之各鋁糊，使得 鋁糊j重量為1.5±0.1克，然後乾燥。此外使用銀糊在矽晶 圓之前表面上印刷手指線(flnger line)然後乾燥。 繼而將已進行以上程序之矽晶圓在紅外線爐中共燒 結，使得燒結區之溫度為720〜900。(：，因而製造太陽電池二 一在共燒結程序中可使石夕晶圓之前與背表面通過帶式焯 而门日守共燒結。在此帶式爐包括約6〇〇。〇之燒毁區及 8〇〇 950 C之燒結區。在此帶式爐中將有機物質自鋁糊二銀 糊去除，然後熔化塗佈在矽晶圓之背表面與前表面上^鋁 糊與銀糊而形成電極。 13/16 201133510 所製造太陽電池之弓翹程度係藉由將太陽電池之四邊 與底部相配’然後測量其中央部分已提高之裎度而評估。 此外以肉眼觀察在鋁背面電極周圍產生之凸塊與鋁球，及 將其計數。結果係示於以下表2。 使用由FitTech Corporation製造之SCM-100(其為—種 評估太陽電池之性能的裝置)評估所製造太陽電池之效率。 結果係示於以下表3。 表2 實施例 1 實施例 2 實施例 3 實施例 4 實施例 5 比較例 1 比較例 2 D5〇=4~6 微米： 2~4微米（重量比 例） 9:1 6:4 9.5:0.5 9:1 9:1 5:5 僅 d50= 2〜4微 米 鋁粉含量 70 重量％ 70 重量％ 70 重量％ 65 重量％ 75 重量％ 70 重量％ 70 重量％ 弓勉（毫米） 02-0.3 0.3-0.5 0.1-0.2 0.2-0.3 0.5-0.8 1.5-2.0 2.5-3.0 凸塊數量 0 1 0 1-2 0 1-2 10-12 表3 實施例 1 實施例 2 實施例 3 實施例 4 實施例 5 比較例 1 比較例 2 Pmax (瓦） 4.2272 4.15587 4.24815 4.1705 4.25596 3.9002 3.7483 效率 (%) 17.691 17.392 17.778 17.453 17.811 16.322 15.687 FF (%) 79.342 ^8.329 79.194 78.42 79.561 74.73 72.116 Isc 8.5322 8.53653 8.53601 8.53601 8.53651 8.3981 8.3767 Voc 0.6244 0.62152 0.62843 0.62302 0.62667 0.6214 0.6205 Rs 0.00622 0.0074 0.00735 0.00754 0.00697 0.00816 0.00986 ※Pmax=太陽電池之最大功率 Isc=短路電流(A)Further, the glass material used in the present invention may have a deuteration point of _~6 〇 (rc). When the amount of the several vehicle liquid is less than 2 G weight%, there is a problem that the printability of the aluminum paste is lowered. 201133510 Reduced by the order, if it is used too much for the arsenic, additives, etc. Organic or more organic solvents used in the present invention, and 2S extraction can include 75% by weight of the vehicle can be further included The polymer resin, and the organic 1~1% by weight of the additive, or less the wetting agent and the rocking agent, and the organic solvent may have a boiling point of 15G~WC, so that it can prevent the flow force. Examples may include diol dipropylene glycol n-dipropylene glycol • di diethylene dihexyl ether, triethylene diethylene glycol fine, ethylene glycol · butyl _, B 4 earth gorge, diethylene glycol ethyl jun, three Ethylene glycol is taken from human B - benzyl ether, terpineol, Texanol®, ethylene glycol, etc. Examples of the alcohol dimer resin may include polyethylene trans ketone, polyethylene ί. Base cellulose, turpentine, phenol resin, acrylic resin, the amount of 隹 & It may be 1 to 25% by weight, and Lu is 5 25 weight/q. When the amount of the polymer resin is less than 1% by weight, the printability and dispersion stability are deteriorated. Further, the amount is more than 25% by weight. J can not print aluminum paste. Face rt As for the burdant and humectant, the shaken β human humectant commonly used in the related field can be used without limitation. The agent, the ruthenium can be used as a dispersant commonly used in related fields. Commercially available surfactants can be used as the dispersion two, and they can be used independently or in combination with each other. Examples of surfactants can include: nonionic interface activity 201133510 agents, such as ethers (including thio-polyoxyethylene) Ether, aryl polyoxyethylene ether, polyoxyethylene-polyoxypropylene copolymer, etc., ester-ether (including polyoxyethylene ether of glyceride, polyoxyethylene ether of sorbitan ester, sorbitol ester) Polyoxyethylene ether, etc., esters (including polyethylene glycol fatty acid esters, glycerides, sorbitan esters, propylene glycol esters, sugar esters, alkyl polyglucosides, etc.), and nitrogen-containing surfactants (including fatty acid alkyl esters) Alcohol amine, polyoxyethylene fatty acid decylamine, polyoxyethylene Alkylamine, amine oxide, etc.; and a polymeric surfactant such as polyvinyl ether 'polyvinylpyrrolidone, polyacrylic acid, polyacrylic acid-maleic acid copolymer, poly-12-base stearic acid, and the like. Examples of commercially available surfactant products may include hypermer KD (manufactured by Uniqema Corp.), AKM 0531 (manufactured by NOF Corp.), KP (manufactured by Shinetsu Kagaku Kogyo Corp.), and POLYFLOW (manufactured by Kyoei Kagaku Corp.). ), EFTOP (manufactured by Tokemu Products Corp.), Asahi guard, Surflon (manufactured by Asahi Glass Corp.), SOLSPERSE (manufactured by Geneka Corp.), EFKA (manufactured by EFKA Chemicals Co. Ltd.), PB 821 (by Ajinomoto Co., manufactured by Ink.), BYK-184, BYK·185, BYK-2160, Anti-Terra U (manufactured by BYK Corp.), and the like. The amount of the dispersing agent may be 1 to 10% by weight, preferably 1 to 5% by weight based on the total amount of the organic vehicle. The aluminum paste according to the present invention can be easily prepared using a planetary mixer which is simultaneously automatic and revolving. That is, the aluminum paste can be prepared by placing the above components in a planetary mixer in a corresponding composition ratio, followed by stirring to appropriately mix and disperse the solid in the organic vehicle. At 25.测量 Measured by Brookfield HBDV-III Ultra Rheometer or mandrel CpE_52. The viscosity of the aluminum paste prepared in this way has a viscosity of 20,000~200,000卬5 at 5卬111 10/16 201133510 =. The rim is capable of preparing an aluminum paste such that it has 4 〇, 〇〇〇 〜1 〇〇, 〇〇 0 () 耻 之 黏 黏 Γ Γ Γ Γ 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造 制造The step of forming the back electrode. A solar cell fabricated with a two-t type is advantageous because it is not easy to bow, and the electrode layer and the break or bump are made such that the values of the pure current (4), the package & (VOC) are significantly improved. The invention will be described in more detail below with reference to the following examples. However, it is limited. The invention is exemplified by ^=, and the scope of the invention is not limited by the scope of the invention, and can be modified by the skilled person without departing from the embodiment 1: preparation of the aluminum paste 3 weight I0/. Then 5〇=4~όmicron aluminum powder, 盥7 Cao Dan D50=2~4 micron powder (4~6 microns: 2 吟, 〇/〇 aluminum powder total=70重哥十9· Η重里比例), the ratio of glass material, weight %% has the composition shown in Table 1 below, and contains ~% of the amount of organic media (which makes the ethyl fiber only ♦ in - (four) towel test The mixture was prepared by mixing the mixture at the same time with automatic and revolving: 2: After mixing for 3 minutes, the butterfly was prepared. The singer's resounding search 11/16 «λ 201133510 Table 1 Ingredient Moer % AI2O3 6.5% SrO 5.5 % Bl2〇3 26.0% Β2Ο3 30.0% Si02 32.0% Total 100% Tg (transfer point) 453 Thermal expansion coefficient (l〇々°C) 77 Tdsp 507 Example 2: Preparation of aluminum paste Prepared in the same manner as in Example 1. Aluminum paste, except for adding 42% by weight of aluminum powder of D5〇=4~6 microns, and 28% by weight of aluminum powder of D5〇=2~4 microns (4~6 microns: 2~4 microns=6:4 ( Weight ratio), total amount of aluminum powder = 70% by weight.) Example 3: Preparation of aluminum paste An aluminum paste was prepared in the same manner as in Example 1, except that 66.5 wt% of aluminum powder of D5〇=4 to 6 μm was added. With 3.5% by weight D5〇=2~4 micron aluminum powder (4~6 micrometers: 2~4 micrometers=9.5:0.5 (weight ratio), total aluminum powder=70% by weight). Example 4: Preparation of aluminum paste as implemented An aluminum paste was prepared in the same manner as in Example 1, except that 58.5 wt% of aluminum powder of D50 = 4 to 6 μm, and 6.5 wt% of D50 = 2 to 4 μm of aluminum powder (4 to 6 μm: 2 to 4 μm = 9:1 (weight ratio), total aluminum powder = 65 wt%), and 34.5 wt% of an organic vehicle. Example 5: Preparation of aluminum paste An aluminum paste was prepared in the same manner as in Example 1, except that 67.5 was added. Weight 12/16 201133510 Quantity% 〇5〇=4~6μm aluminum powder, with 7.5wt% 〇5〇=2~4μm|Lu powder (4~6 is m, 2~4 is m= 9:1 (weight ratio), a total amount of powder; wt%), and 24.5 wt% of an organic vehicle. Comparative Example 1: Preparation of aluminum paste An aluminum paste was prepared in the same manner as in Example 1, except that 35 was added. 5% by weight of 〇5〇=4~6 microns of Shao powder, with 35 weights of D5〇:=2~4 micro-mined aluminum powder (4~6 microns: 2~4 microns=5:5 (weight Proportion), total amount of aluminum powder = 7 〇 wt%), and 29.5% by weight of organic vehicle. Comparative Example 2: Preparation of aluminum paste An aluminum paste was prepared in the same manner as in Example 1 except that 7 wt% of ruthenium > 5 〇 = 2 to 4 μm of Shao powder, and 29.5% by weight of an organic vehicle were added. Test Example: Manufacture of solar cells and testing of their characteristics. The surface of a single crystal germanium wafer having a size of 156 X 156 3⁄4 m and a thickness of 200 μm is textured. The height of the pyramid is about 4 to 6 μm, and the wafer is textured. The N-side is coated with SiNx. Then, the bus bar is printed on the back surface of the wafer and then dried, and then the aluminum pastes of Examples 1 to 5 and Comparative Examples 2 to 2 are coated thereon using a 250 mesh screen printing plate to make aluminum. The paste j weighed 1.5 ± 0.1 g and was then dried. Further, a silver paste was used to print a flnger line on the surface before the twinning circle and then dried. Then, the wafers which have been subjected to the above procedures are co-fired in an infrared furnace so that the temperature in the sintering zone is 720 to 900. (:, Thus, the solar cell manufacturing of the solar cell can be used in the co-sintering process to make the Shixi wafer and the back surface pass through the belt 焯 and the door is co-sintered. The belt furnace includes about 6 〇〇. Zone and 8 950 C sintering zone. The organic material is removed from the aluminum paste and silver paste in the belt furnace, and then melt coated on the back surface and the front surface of the silicon wafer. The electrode is formed. 13/16 201133510 The degree of bowing of the manufactured solar cell is evaluated by matching the four sides of the solar cell to the bottom and then measuring the increased degree of the central portion of the solar cell. Furthermore, it is visually observed around the aluminum back electrode. The bumps and aluminum balls were counted and the results are shown in Table 2. The efficiency of the manufactured solar cells was evaluated using SCM-100 manufactured by FitTech Corporation, which is a device for evaluating the performance of solar cells. The results are shown in Table 3 below. Table 2 Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 D5 〇 = 4 to 6 μm: 2 to 4 μm (weight ratio) 9:1 6:4 9.5:0.5 9:1 9:1 5:5 only d50= 2~4 micro Rice aluminum powder content 70% by weight 70% by weight 70% by weight 65% by weight 75% by weight 70% by weight 70% by weight Bow 勉 (mm) 02-0.3 0.3-0.5 0.1-0.2 0.2-0.3 0.5-0.8 1.5-2.0 2.5- 3.0 Number of bumps 0 1 0 1-2 0 1-2 10-12 Table 3 Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Pmax (Watt) 4.2272 4.15587 4.24815 4.1705 4.25596 3.9002 3.7483 Efficiency (%) 17.691 17.392 17.778 17.453 17.811 16.322 15.687 FF (%) 79.342 ^8.329 79.194 78.42 79.561 74.73 72.116 Isc 8.5322 8.53653 8.53601 8.53601 8.53651 8.3981 8.3767 Voc 0.6244 0.62152 0.62843 0.62302 0.62667 0.6214 0.6205 Rs 0.00622 0.0074 0.00735 0.00754 0.00697 0.00816 0.00986 ※Pmax = maximum power of solar cell Isc = short circuit current (A)
Voc=斷路電壓(v)Voc = open circuit voltage (v)
Rs=串聯電阻 FF=填充因子 實施例6:鋁糊印刷量之控制 改&條件而將實施例1製備之鋁糊以1.0克、1.2克、 14/16 201133510 ]5 1 8 古 x ^ _ •兄、與2.0克之量印刷，然後以上述之相同方式 刀P席J之!呂物。結果係示於以下表4。 表4Rs = series resistance FF = fill factor Example 6: Control of the amount of aluminum paste printing & conditions The aluminum paste prepared in Example 1 was 1.0 g, 1.2 g, 14/16 201133510] 5 1 8 ancient x ^ _ • Brother, print with a quantity of 2.0 grams, and then knife P in the same way as above! The results are shown in Table 4 below. Table 4
~T知’基於銘糊印刷量’太陽電池之效率差異 此可得到充分之太陽電池效率，即使是相較於使 用、，句2克之小量鋁糊(其為市售量)時。 雖然為了例證之目的已揭示本發明之較佳具體實施 :’熟悉此技藝者應了解，在不背離在所附申請專利範圍 =之本發明之範圍及精神下，各種修改、添加 為可行。 【圖式簡單說明】 Μ 【主要元件符號說明】~T knows 'Based on the difference in the amount of printing ink' efficiency of solar cells, this gives a sufficient solar cell efficiency, even when compared to the use, a small amount of aluminum paste (which is commercially available). Although the preferred embodiment of the invention has been disclosed for the purpose of illustration, it will be understood by those skilled in the art that various modifications and additions are possible without departing from the scope and spirit of the invention. [Simple description of the diagram] Μ [Main component symbol description]
S 15/16S 15/16