200947718 九、發明說明： 【發明所屬之技術領域】 特別是關於一種用於太陽 本發明與一種導電膠有關 能電池之導電膠。 【先前技術】 、太陽能發電產業是一個充滿發展遠景之新興產業，已 逐漸從能源概念產業中脫穎而出。目前 ❸涨，全球的石油資源有限’加上京都議定書對於 之環保意識抬頭，使得傳統燃石油、燃煤等發電方式受到 限制。故此’世界主要國家近年來積極研發以潔淨之二生 能源來取代礦物燃料發電，以減輕傳統發電方式所產生之 污染問題。在替代性能源中，無論是太陽能、風能、地敎 能：生質能等’均為各先進國家共同推展之目標，其中’， 尤以太陽此之應用需求最為強烈。據太陽能研究機構200947718 IX. Description of the invention: [Technical field to which the invention pertains] In particular, it relates to a conductive adhesive for solar cells of the present invention and a conductive adhesive. [Prior Art] The solar power industry is an emerging industry full of development prospects and has gradually emerged from the energy concept industry. At present, the global oil resources are limited. Together with the Kyoto Protocol's awareness of environmental protection, traditional power generation methods such as burning oil and coal are limited. Therefore, in recent years, the world's major countries have actively developed research and development to replace fossil fuel power generation with clean secondary energy to reduce the pollution caused by traditional power generation methods. Among the alternative energy sources, whether it is solar energy, wind energy, mantle energy: biomass energy, etc., are the targets of the advanced countries, among which the demand for the sun is particularly strong. Solar research institute
Solarbuzz調查顯示，在過去二十年内，太陽能光電的需求 ❹呈現向上發展的趨勢。從太陽能光電系統安裝量來看，全 球的安裝量自2001年至纖年，已從34()mw攀升至 1，744MW’ 5年之間的成長逾5倍，每年平均增幅約所〇。 可預見太陽能發電在未來人類能源利用方面扮演的角色越 來越重要。 太陽能電池⑽ar eell)是—種可將光能轉換成電能之 裝置’其-般是以半導體材料，如包含單晶石夕、多晶石夕及 非晶矽等矽基材，或是化合物半導體，如GaAs、Gap、inp、The Solarbuzz survey shows that in the past two decades, the demand for solar photovoltaics has shown an upward trend. From the perspective of the installed capacity of solar photovoltaic systems, the global installed capacity has increased from 34 () mw to 1,744 MW' over 5 years since 2001 to the annual growth rate, and the average annual growth rate is about the same. It is foreseeable that the role of solar power in the future use of human energy is becoming more and more important. A solar cell (10) is a device that converts light energy into electrical energy. It is generally a semiconductor material, such as a germanium substrate containing monocrystalline, polycrystalline, and amorphous germanium, or a compound semiconductor. , such as GaAs, Gap, inp,
AlGaAs等皿、V族元素化合物基材所製成。以矽基材而 4 200947718 吕，業者一般作法是在P型矽基材（P_type)正面的受光區域 摻雜磷原子（phosphorus)以形成一負電極區而其背面未受 光之區域則為對應之正電極端。上述半導體基材中所形成 之PN接面（pn juncti〇n)會將特定波長（”之入射光能量轉 換成電子電洞對（e- _ h+ pair)往兩電極相反方向移動而產 生出電流，該電流即為太陽能電池的電能來源。一般而言， 矽基材的受光面還會鍍上一層抗反射膜（ARC，如氮化矽 ❹SlNx薄膜），來避免光反射造成的能量損失，以增加太陽能 電池的轉換效率η (efficiency)。除了上述太陽能電池之半 導體基材外’業者-般都會在PN介面完成後於石夕基材背 面形成一層鋁背面電場（BSF，backsurfacefield)。鋁背面 電％可減少少數載子（及電子e-、電洞h+)在背面復合 (recombination)的機率，亦可用來作為電池的背面電極， 進而改善太陽能電池的轉換效率。製作該鋁背面電場最簡 單的方式係為在矽基材背面塗佈一層鋁膜並燒結使鋁原子 ❹擴散進入矽晶片内，形成一高鋁摻雜濃度（Al_d〇pant)之p+ 層。 為了將太陽能電池所產生的電流導引出來成為可用之 電能，半導體基材0兩端還須形成金屬電極來將電流導至 外部的電流負載端（load)。然，基材受光面（即正面）之金屬 電極會擋住受光面而阻礙太陽光之吸收，故太陽能電池的 正面金屬電極面積越小越好，以增加太陽能電池的受光區 域。故此，現今一般的金屬電極主要是利用網印技術⑽咖 Pnndng)在太陽能電池的兩正反面印製出網狀電極結構。 5 200947718 所謂的網印電極備製，即係利用網印的方法，把導電金屬 水料（即導電膠）依照所設計之圖形印刷在已經換雜過的石夕 基材上，並在適當的燒結條件下將導電金屬漿料♦的有機 溶劑揮發，使金屬顆粒與表面的石夕形成石夕合金，形成石夕材 之間良好的歐姆接觸，進而成為太陽能電池的正反面金屬 電極。但是，過細的電極網線易造成斷線，或使其電阻升 高而降低了太陽能電池的轉換效率’故如何達到細線化又 不，低電池整體的發電效率便為此領域之技術重點。一般 而5，金屬電極的膜厚約為1〇〜25 μηι，而正面金屬的網線 (finger line)寬度約為^0450 μπι。以此類技術來製作太陽 能電池電極有自動化、高產能及成本低之優點。 綜上所言可知，除了形成ΡΝ接面的半導體基材外， 製作太陽能電池最主要的材料就是導電膠(paste)的部分。 導電膠的成分、含量、比例、製程參數等都會影響到最後 電極產物之性能。以正面金屬電極為例，其用以形成之導 ❹電膠優劣就會直接影響到各項i要的太陽能電池性能，如 轉換效率η、開路電壓V〇c(〇pen circuit v〇1Uge)、短路電流 Isc(short circuit current)、填充因子 F F (fiU fact〇r)、串聯 電阻Rs(series resistance)、以及分流電阻& (81^加 resistance)等，亦會決定有效之燒結溫度範圍八與黏著力 (adhesion strength)之大小。故如何調配出一種能改善上述 各項太陽能電池性能之導電膠為目前業界研發之重點。 一般先前技術中的導電膠都會加入含鉛（pb)材料，如 氧化錯PbO。氧化鉛的添加能達料多優異的效果，如降 6 200947718 低導電膠的燒結溫度、降低導電膠與半導體基材之間的接 觸電阻。然而，在現今環保意識的抬頭下，含紹或含録等 污染性材料（如氧化鎘CdO)已被禁止大量使用在工業產品 上以免對人體造成傷害。故此，目前業界正在積極尋找或 開發含有其他元素成分之導電膠，以期製作出一具有優越 性能的太陽能電池。 【發明内容】 ❺ 鑑於上述習知技術之缺點，本發明提出了一種用於太 ^能，池之導電膠，其配方組成可在不含鉛（pb)成分的條 下達到或超越先前技術中含有錯成分太陽能電池所能達 丨之轉換效率以及電性表現。本發明之導電膠包含了 比例範圍之銀粉、玻璃溶塊、有機載體以及添 盆 用:連結太陽能電池基材作為-電極以將太陽能電池產ί 之電流導出。 ％。座玍 ❹ 在本發明一實施例中，其導電膠的玻璃熔a 有銘與/或鉈氧化物，且其中不人璃嫁塊組成中含 3 4何3鉛成分。此導電勝 =:驗與測試*實能達到優良的太陽能電池性能，如 開路電心。。、短路電流…填充因子π 曰不此外，其有效燒結溫度範圍亦較大。 含有it明另一實施例中，其導電膠的玻璃熔塊組成中 分^導電物以及氣化物’且其中不含任何含錯成A substrate such as AlGaAs or a group V element compound is used. It is common practice for the substrate to be doped with a phosphorus atom in the light-receiving region on the front side of the P-type germanium substrate (P_type) to form a negative electrode region and the region on the back side that is not exposed to light is corresponding. Positive electrode end. The PN junction formed in the semiconductor substrate converts incident light energy of a specific wavelength into an electron hole pair (e- _ h+ pair) to move in opposite directions of the two electrodes to generate a current. The current is the source of electrical energy for the solar cell. Generally, the light-receiving surface of the ruthenium substrate is also coated with an anti-reflection film (ARC, such as a tantalum nitride SlNx film) to avoid energy loss caused by light reflection. Increasing the conversion efficiency η (efficiency) of the solar cell. In addition to the semiconductor substrate of the above solar cell, the industry will form an aluminum back surface field (BSF, backsurfacefield) on the back side of the stone substrate after completion of the PN interface. % can reduce the probability of minority carriers (and electron e-, hole h+) in the back recombination, and can also be used as the back electrode of the battery, thereby improving the conversion efficiency of the solar cell. The simplest electric field on the back surface of the aluminum is made. The method is to apply an aluminum film on the back surface of the ruthenium substrate and sinter the aluminum atom ❹ into the ruthenium wafer to form a high aluminum doping concentration (Al_d〇pant) p+ In order to guide the current generated by the solar cell into usable electrical energy, a metal electrode must be formed at both ends of the semiconductor substrate 0 to conduct current to an external current load. However, the substrate is exposed to light (ie, The metal electrode on the front side blocks the light-receiving surface and hinders the absorption of sunlight. Therefore, the smaller the metal electrode area on the front side of the solar cell, the better, so as to increase the light-receiving area of the solar cell. Therefore, the current metal electrode is mainly using screen printing technology. (10) Coffee Pnndng) printed a mesh electrode structure on both front and back sides of the solar cell. 5 200947718 The so-called screen printing electrode preparation method uses the method of screen printing to design the conductive metal water material (ie conductive glue) according to the design. The graphic is printed on the Shixi substrate which has been replaced, and the organic solvent of the conductive metal paste ♦ is volatilized under appropriate sintering conditions, so that the metal particles form a stone alloy with the surface of the stone, forming a stone material. Good ohmic contact between them, which becomes the front and back metal electrodes of the solar cell. However, the excessively thin electrode wire tends to cause wire breakage, or The increase in resistance reduces the conversion efficiency of the solar cell. Therefore, how to achieve thinning and not, the overall power generation efficiency of the low battery is the technical focus of this field. Generally, the thickness of the metal electrode is about 1 〇 25 25 μm. The front metal has a finger line width of about ^0450 μπι. The use of such technology to fabricate solar cell electrodes has the advantages of automation, high productivity, and low cost. In summary, in addition to the formation of the splicing surface. Outside the semiconductor substrate, the most important material for making solar cells is the part of the conductive paste. The composition, content, ratio, and process parameters of the conductive paste affect the performance of the final electrode product. Taking the front metal electrode as an example, the advantages and disadvantages of the conductive paste used to directly form it will directly affect the performance of various solar cells, such as conversion efficiency η, open circuit voltage V〇c (〇pen circuit v〇1Uge), The short circuit current Isc (short circuit current), the fill factor FF (fiU fact〇r), the series resistance Rs (series resistance), and the shunt resistor & (81 ^ plus resistance), etc., will also determine the effective sintering temperature range of eight The size of the adhesion strength. Therefore, how to deploy a conductive adhesive that can improve the performance of the above solar cells is the focus of current research and development in the industry. Generally, conductive pastes in the prior art are added to lead (pb) materials such as oxidized PbO. The addition of lead oxide can achieve many excellent effects, such as the sintering temperature of the low conductive adhesive and the contact resistance between the conductive paste and the semiconductor substrate. However, under the current environmental awareness, contaminated materials such as cadmium or cadmium (such as cadmium oxide CdO) have been banned from being used in industrial products to avoid harm to humans. Therefore, the industry is actively looking for or developing conductive adhesives containing other elemental components in order to produce a solar cell with superior performance. SUMMARY OF THE INVENTION In view of the above-mentioned shortcomings of the prior art, the present invention proposes a conductive adhesive for a solar cell, whose composition can meet or exceed the prior art under the strip containing no lead (pb) component. The conversion efficiency and electrical performance of the wrong component solar cell can be achieved. The conductive paste of the present invention comprises a proportion range of silver powder, a glass soluble mass, an organic carrier, and an additional pot: a solar cell substrate is bonded as an electrode to derive a current of the solar cell. %. In one embodiment of the present invention, the glass of the conductive paste has a melting and/or cerium oxide, and wherein the composition of the non-glazed briquettes contains 3 3 and 3 lead components. This conductivity win =: test and test * can achieve excellent solar cell performance, such as open circuit. . Short-circuit current...fill factor π 曰 In addition, the effective sintering temperature range is also large. In another embodiment, the glass frit of the conductive paste is composed of a conductive material and a vaporized material, and does not contain any faulty
電池性能，如與測試證實能達到優良的太陽能 如轉換效率η、開路電壓v〇c、短路電流J 充因子F.F等各項指標。此外，其有效燒結溫度^ 7 200947718 亦較大。 本發明導電膠之製作方式亦於本發明書中揭示，其係 將本發明之導電膠以網印方式印在半導體基材上，並於高 溫爐中將其燒結成固態的電極。 本發明之一目的，為提供一種不含鉛成分之太陽能電 池導電膠； 本發明之另一目的，為提供一種含鉈成分之太陽能電 池導電膠；Battery performance, such as testing and testing, can achieve excellent solar energy such as conversion efficiency η, open circuit voltage v〇c, short-circuit current J charge factor F.F and other indicators. In addition, its effective sintering temperature ^ 7 200947718 is also larger. The method of making the conductive paste of the present invention is also disclosed in the present invention, which is obtained by screen printing a conductive paste of the present invention on a semiconductor substrate and sintering it into a solid electrode in a high temperature furnace. One object of the present invention is to provide a solar cell conductive paste containing no lead component; another object of the present invention is to provide a solar cell conductive paste containing a bismuth component;
本發月之又目的，為提供一種太陽能電池用導電 膠’其具有優良的轉換效率η、開路電壓L、短路電流^ 以及填充因子F.F ,亦具有較大的燒結溫度範圍； 本發月之又-目的，為提供一種上述本發明太陽能電 池用導電膠之製作方法。 著 摩巳 、本發明刖述之形式、目的、觀點、特徵及優點將隨 以下較佳f施财詳細的描述及其伴隨之圖式而愈見明 其細節描述與圖式❹以述明本發明。而本發明之 命將由隨附之專利請求項來定義。 【實施方式】 Μ本發明將針對發明具體實_及其觀點加 =此類描述為解釋本發明之結構或步驟流程，其係供 此，除說明奎* 乃甲。月專利㈣限制之實。因 可廣實施例與較佳實施例外，本發明亦 了廣泛軛仃於其他不同的實施例中。 本發明所提出之導電膠係用以形成太陽能電池基材之 8 200947718The purpose of this month is to provide a conductive paste for solar cells which has excellent conversion efficiency η, open circuit voltage L, short circuit current ^ and fill factor FF, and also has a large sintering temperature range; - A purpose is to provide a method for producing a conductive paste for a solar cell of the present invention. The form, purpose, viewpoint, features, and advantages of the present invention will be described in detail with reference to the detailed description and accompanying drawings. invention. The life of the present invention will be defined by the accompanying patent claims. [Embodiment] The present invention will be described with respect to the invention and its aspects plus the description of the structure or the flow of the steps of the present invention, which is for the sake of illustration, except for the description of Kui. The monthly patent (4) is limited. The invention is also broadly conjugated to other different embodiments, with the exception of the various embodiments and preferred embodiments. The conductive adhesive proposed by the invention is used to form a solar cell substrate 8 200947718
池所具偌文光面)，其技術特徵在於改善各項太陽能電 雷、ώ 了、之各項特性，如轉換效率n、開路電壓v。。、短路 以及填充因子F.F等，並於燒結後能與其下方的基 材形成良好的附著（adhesion)。為達上述目的本發明之導 電膠成刀大體上包含了銀粉（Ag)、玻璃溶塊邮）、有機載 體（vehicle)、以及各類添加劑（祕出彻）。銀是導電性非常 好的介質’於發明實施例中，銀粉顆粒可為片狀（歸… 球狀（spherical)或兩者之混合。銀粉的顆粒大小會影響導電 膠，結的速度’―般而言，銀顆粒越大則燒結速度越慢， 亦谷易產生燒結不完全之現象使電極的導電度與強度降 低^而顆粒太小又會使部分區域燒結過快，使得銀與^他 ^分之介©處產生裂縫。於本發明實施例中，其銀粉粒徑 分佈在0.1〜10.0 _之間。在實施例中，只要導電膠銀成 分含量能達到本發明之目的，本發明並不會特別對其比例 加以限定。不過就實施例而言，其銀粉比例約佔整體導電 膠重量60〜90wt %(重量百分比）為佳。 在本發明實施例中’有機載體是分別以有機溶劑與樹 脂調配而成’其有機溶劑最好是由二種以上的溶劑混合而 成，如醇醚類的二甘醇一丁醚（Butyl Carbitol，DB；)、α 松油醇（alpha- Terpineol)、Texanol成膜劑等；樹脂亦以一 種以上不同分子1的纖維素混合為佳，如乙基纖維素 (Ethyl cellulose，EC)或其混合物。在實施例中，只要有機 載體的含量能達到本發明之目的，本發明並不會特別對其 比例加以限定。不過就實施例而言，其比例含量佔約整體 9 200947718 導電膠重量10〜30wt %為佳。 在玻璃熔塊方面，其組成中含有鉈T1與/或鉈氧化物 Tl2〇/T10/ Tl2〇3之成分，並可以選擇性包含了其他如The technical characteristics of the pool are to improve various solar electric mines, smashing, and various characteristics, such as conversion efficiency n and open circuit voltage v. . Short circuit and filling factor F.F, etc., and after sintering, can form a good adhesion to the underlying substrate. In order to achieve the above object, the conductive paste forming blade of the present invention generally comprises silver powder (Ag), a glass-soluble block, an organic carrier, and various additives (Secret). Silver is a medium with very good conductivity. In the embodiment of the invention, the silver powder particles may be in the form of a sheet (spherical or a mixture of the two. The particle size of the silver powder affects the conductive paste, the speed of the knot' In other words, the larger the silver particles, the slower the sintering speed, and the more likely the sintering is incomplete, the lower the conductivity and strength of the electrode. The smaller the particles, the more the sintering will be too fast, so that the silver and ^^^ In the embodiment of the present invention, the particle size distribution of the silver powder is between 0.1 and 10.0 _. In the embodiment, as long as the content of the conductive silver component can achieve the object of the present invention, the present invention does not In particular, the ratio of silver powder is about 60 to 90% by weight (% by weight) based on the weight of the entire conductive paste. In the embodiment of the present invention, the organic carrier is organic solvent and The resin is prepared by mixing the organic solvent with two or more solvents, such as an alcohol ether of Butyl Carbitol (DB;) and alpha terpineol. Texanol film formation The resin is also preferably mixed with cellulose of one or more different molecules 1, such as ethyl cellulose (EC) or a mixture thereof. In the examples, as long as the content of the organic vehicle can achieve the object of the present invention, The invention is not particularly limited in its proportion. However, in the case of the embodiment, the proportion of the conductive rubber is preferably about 10 to 30% by weight of the total of 9 200947718. In terms of glass frit, the composition contains 铊T1 and / Or bismuth oxide Tl2 〇 / T10 / Tl2 〇 3 components, and optionally include other
PbO、Bi203、Si02、Α12〇3、Β2〇3、K2C03、ZnO、KF/CaF2/BF3 成分不同比例之組合，其平均粒徑約在1〇 μιη以下，如要 增加銀與矽之間的傳導或降低銀的電阻率（即提升轉換效 率），可再選用更小的溶塊粒徑，如平均粒徑小於5 或 1 μιη以下。在實施例中，只要玻璃熔塊的含量能達到本發 明之目的，本發明並不會特別對其比例加以限定。不過就 實施例而言，其比例含量佔約整體導電膠重量0〜10wt%為 佳。 ‘ 此外，本發明導電膠亦可視各項需求添加一定含量的 添加劑，如分散劑（dispersant)、流平劑（levelling agent)、 觸變劑（thixotropic agent)、穩定劑（stabilizer)、黏度調節劑 (viscosity adjuster)、以及介面活性劑（surfactant),助劑， ❿其含量約佔導電膠整體〇〜5wt%之間。其主要作用係為調 整膠體之黏度且具有潤濕與粒子均勻分散的功能，亦可增 進燒結後金屬粒子的緊密度、導電度，故添加二種以上^ 添加物能達到更佳的效果。 在下列的表一中，其表示了本發明實施例中用以進行 實驗比較的各組導電膠成分比例： 表一 200947718 比較例I 比較例II 應用實施例I 應用實施例II _.商品化銀麻 乙基織維素(Wt°/o) 2.6 2.6 2.6 — 2.6 有機溶劑（Wt%) 12.3 12.3 12.3 12.3 - 銀粉（wt%) 79.6 79.6 79.6 79.6 玻璃種類 玻璃A 玻璃B 玻璃C 玻璃D ' --- 玻璃含量（Wt%) 2.8 2.8 2.8 2.8 ----- 添加助劑（wt%) 2.7 2.7 2.7 2.7 --—-—— 從表一中可得知’本發明將實驗分成五組組成比例不 同之導電膠來作比較。實施例中前面四組的成分組成，除 了使用的玻璃種類不同外（玻璃A〜D)，其它成分的比例皆 相同’銀粉佔79.6wt % ;有機溶劑與乙基纖維素分別佔了 12.3 wt°/〇與2.6wt% ;玻璃含量佔2.8wt% ;而添加助劑佔 了 2.7wt %。商品化銀膠則為目前一般市面上常用之含錯 銀膠，型號為PV145(DuPont)，其目的在於比較習知技術 中含鉛銀膠與本發明不含鉛銀膠性能之差別。隨之參照表 二。表二為說明各比較組中玻璃熔塊的成分與含量組成： 表二 玻璃熔塊組成物 T1/T120/T10/T1,0, 玻璃A(wt%) 0 璃 B (wt0/〇) 玻璃C (wt%) 玻璃D 5~50 0 5~50 PbO 50〜90 50-90 0 〇 Bi2〇3 0〜1 0~1 20-50 20-50 Si02 5~20 5〜20 5-30 5-30 ai2o, 0〜1 0〜5 5~20 5〜20 b2o3 1~10 Γ 1〜10 5~20 5~20 k2co3 0〜1 1-5 0〜1 ZnO 0〜1 0〜1 0~1 1-10 KF/CaF2/BF, "5FT以彳主—山 0 0 0 0-5 可從表二中得知，各組導電膠之玻璃熔塊主要是由不1 同比例之金屬與/或金屬氧化物所組成，其中包含了鉈與鉈 氧化物（T1/T120/T10/T1203)、氧化鉛（Pb〇)、氧化鉍（Bi2〇3)、 11 200947718 ❹ 氧化矽（Sl〇2)、氧化鋁（ai2〇3)、氧化硼（b2o3)、碳酸鉀 (K2C〇3)、氧化辞（Zn〇)以及氟化物（KF/CaF2/BF3)等。在破 璃A與玻璃B的比較例中，其組成中含有5〇〜％的 氧化鉛，且不含任何的鉈與/或鉈氧化物，兩玻璃之成分差 另J在於玻璃A所含之α〗2〇3成分為〇〜iwt%，玻璃b為〇 〜5wt %為。相反地，在玻璃c與玻璃D的比較例中，其 組成中含有5〜50wt。/❶的鉈與/或鉈氧化物，以及其他比例 的金屬氧化物（如20〜50wt %的Bi2〇3、5〜20wt %的 Al2〇3)，但其甲卻不含任何鉛成分。此外，玻璃d還含有 〇〜5Wt%比例的氟化物。此實驗設計之目的在於比較含鉈 成分與含錯成分導電膠之性能，以及是否能以其他非鉛金 屬之氧化物來取代一般習知技術中常用的氧化鉛。 在本發明實施例中，其係針對各組比較例所測得之太 陽能電池特性作比較，包含了轉換效率η、開路電壓^、 短路電流Ise以及填充因子F.F等各項指標，將—在下°面 ❹作說明。首先參照圖-，其為本發明實施例各組導電膠之 轉換效率η比較。轉換效率η為太陽能電池性能中最重要 $一個指標，其關係到所接收之光能有多少比例能轉換為 I供利用之電能。可從圖中看出，比較例I與比較例Μ 乂低燒結溫度下（88代以下）的轉換效率η非常差，約只有 =到9%的水準。相較之下，應用實施例ζ與應用實施例η :在峨的燒結溫度能達到一定的轉換效率。由此看 88〇。^有錯成分的比較例卜11之有效燒結溫度範圍約在 〜960 c之間’而含有鉈成分的應用實施例I、Π之 12 200947718 有效燒結溫度範圍勒仏上 ^ 圓較大，約在86〇。(：〜96(TC之間。較大的 溫度範圍可予以更製造去 L 士 褽化者更夕的製程調整空間。而在轉換 效#面’從圖中可看出應用實施例！、Π可達到之轉換 功^大^較比較例卜Η及—般商品化銀膠來的高，、 此Ρ思味著實施例中以銘成分⑺/τΐ2〇/τι〇/τΐ2〇3)可取代 一般習知技術中之料分剌於商品化應用。就本實施例 轉換效率之實驗結果’含有銘成分的應用實施例ί、Π不 ❹ 僅轉換功率尚，其燒結溫度範圍亦廣，故於此方面可有良 好的應用。 請參照圖二，其為本發明實施例中各組導電膠之開路 電壓v:c比較。所謂開路電壓即為太陽能電池在負載無限 大的隋況了 A就疋外部電流斷路時所量到之電壓。此時 的輸出電流為0。開路電壓v〇c值關係到太陽能電池之最 大功率點（maximum power p〇int，Mpp)，即所能輸出之最大 功率…般而言’當太陽能電池所能產生之開路電壓值^ 〇與短路電流18。值越大時，其所能產生之功率輸出越大。由 圖二可看出各實驗組於各燒結溫度條件下所得到之開路電 壓voc值約略在同樣的水準，顯示本發明導電膠以蛇來取 代習知技術中的錯成分可達到與先前技術中同水準之開路 電壓V。。表現。 接著參照圖三，其為本發明實施例中各組導電膠之短 路電流Isc比較。短路電流即是太陽電池在無負荷狀態下， 也就是外部電路短路時的輸出電流，此時電壓為0。在理 想狀態下，太陽能電池的短路電流即等於照光時所產生之 13 200947718 太陽能電幵异 v°e之原理，短路電流1se之值關係到 所处二山，之最大功率點（maximum P〇wer point, MPP)，即 月匕别之最大功率。一般而言，當太陽能電池所能產生 :短：電流!sc值越大時’其所能產生之功率輸出越大。如 =h ’比較例！、„之短路電流^值在低燒結 (⑽：下)非常低，約只有7.7A之水準，進而影響到直 =燒結溫度範圍。相較之下，應用實施例卜π在燒 「= χ 860 C〜960 C之間的範圍都有著不錯的短路電流 二膜ίΐ於各燒結溫度之電流表現都較-般市售之商品 取代f知技術中的錯成分可達到相同甚至更佳的短路電ίPbO, Bi203, SiO2, Α12〇3, Β2〇3, K2C03, ZnO, KF/CaF2/BF3 combinations of different proportions, the average particle size is below 1〇μηη, to increase the conduction between silver and yttrium Or to reduce the resistivity of silver (ie, improve conversion efficiency), you can choose a smaller particle size, such as an average particle size of less than 5 or 1 μηη. In the examples, the present invention is not particularly limited in its proportion as long as the content of the glass frit can achieve the object of the present invention. However, in the case of the examples, the proportion of the conductive paste is preferably from 0 to 10% by weight based on the total weight of the conductive paste. In addition, the conductive paste of the present invention may also add a certain amount of additives according to various requirements, such as a dispersant, a levelling agent, a thixotropic agent, a stabilizer, a viscosity modifier. (viscosity adjuster), as well as surfactants, auxiliaries, and cerium, which accounts for about 5% by weight of the conductive enamel. Its main function is to adjust the viscosity of the colloid and have the function of wetting and uniform dispersion of particles, and can also increase the tightness and conductivity of the metal particles after sintering, so adding two or more additives can achieve better results. In the following Table 1, it shows the proportions of the conductive adhesive compositions of each group used for experimental comparison in the examples of the present invention: Table 1 200947718 Comparative Example I Comparative Example II Application Example I Application Example II _. Commercialized silver Hexyl acetonide (Wt°/o) 2.6 2.6 2.6 — 2.6 Organic solvent (Wt%) 12.3 12.3 12.3 12.3 - Silver powder (wt%) 79.6 79.6 79.6 79.6 Glass type glass A glass B glass C glass D ' -- - Glass content (Wt%) 2.8 2.8 2.8 2.8 ----- Additives (wt%) 2.7 2.7 2.7 2.7 ----- As can be seen from Table 1, the invention divides the experiment into five groups. Different conductive adhesives are used for comparison. In the examples, the composition of the first four groups is different except that the type of glass used (glass A to D), the ratio of other components is the same 'silver powder accounts for 79.6 wt%; organic solvent and ethyl cellulose account for 12.3 wt. /〇 and 2.6 wt%; glass content accounts for 2.8 wt%; and additive added accounts for 2.7 wt%. Commercialized silver glue is currently used in the market, and the type of silver-containing glue is PV145 (DuPont). The purpose is to compare the difference between the lead-containing silver glue and the lead-free silver glue of the present invention. Then refer to Table 2. Table 2 shows the composition and content composition of the glass frit in each comparison group: Table 2 Glass frit composition T1/T120/T10/T1,0, glass A (wt%) 0 glass B (wt0/〇) glass C (wt%) Glass D 5~50 0 5~50 PbO 50~90 50-90 0 〇Bi2〇3 0~1 0~1 20-50 20-50 Si02 5~20 5~20 5-30 5-30 Ai2o, 0~1 0~5 5~20 5~20 b2o3 1~10 Γ 1~10 5~20 5~20 k2co3 0~1 1-5 0~1 ZnO 0~1 0~1 0~1 1- 10 KF/CaF2/BF, "5FT to 彳主—山0 0 0 0-5 It can be seen from Table 2 that the glass frit of each group of conductive adhesive is mainly composed of metal and/or metal in the same proportion. Oxide consisting of lanthanum and cerium oxides (T1/T120/T10/T1203), lead oxide (Pb〇), bismuth oxide (Bi2〇3), 11 200947718 ❹ 矽 矽 (Sl〇2), oxidation Aluminum (ai2〇3), boron oxide (b2o3), potassium carbonate (K2C〇3), oxidized (Zn〇), and fluoride (KF/CaF2/BF3). In the comparative example of the glass A and the glass B, the composition contains 5 〇 to % of lead oxide, and does not contain any bismuth and/or bismuth oxide, and the difference between the components of the two glasses lies in the glass A. α 〇 2 〇 3 components are 〇 ~ iwt%, and glass b is 〇 ~ 5 wt%. On the contrary, in the comparative example of the glass c and the glass D, the composition contained 5 to 50 wt. / ❶ 铊 and / or 铊 oxide, and other proportions of metal oxides (such as 20 ~ 50wt% Bi2 〇 3, 5 ~ 20wt% Al2 〇 3), but its A does not contain any lead components. Further, the glass d also contains a fluoride in a ratio of 〇 5 5 tt%. The purpose of this experimental design was to compare the properties of the conductive composition containing the bismuth component with the wrong component, and whether it could replace the lead oxide commonly used in the conventional art with other non-lead metal oxides. In the embodiment of the present invention, it compares the solar cell characteristics measured by each group of comparative examples, and includes various indexes such as conversion efficiency η, open circuit voltage ^, short-circuit current Ise, and fill factor FF, and will be - under For details. Referring first to the drawings, it is a comparison of the conversion efficiencies η of the conductive pastes of the respective groups of the present invention. The conversion efficiency η is the most important one of the solar cell performance. It is related to the proportion of the received light energy that can be converted into I for use. As can be seen from the graph, the conversion efficiency η of the comparative example I and the comparative example 乂 乂 low sintering temperature (88 generations or less) is very poor, and only about = 9% level. In contrast, the application example 应用 and the application example η: a certain conversion efficiency can be achieved at the sintering temperature of the crucible. Let's look at 88〇. ^Comparative example of the wrong component, the effective sintering temperature range is about ~960 c' and the application of the bismuth component is the same as in the application example I, Π12 200947718 The effective sintering temperature range is larger than the circle, about 86〇. (: ~96 (between TC. The larger temperature range can be made more to the process adjustment space of the L 褽 褽 褽 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 转换 转换 转换 转换 转换 转换 转换 转换 转换 转换 转换 转换The conversion power that can be achieved is higher than that of the comparative example and the commercialized silver glue. This can be replaced by the name component (7)/τΐ2〇/τι〇/τΐ2〇3). In general, the materials in the prior art are divided into commercial applications. The experimental results of the conversion efficiency of the present embodiment 'the application examples containing the inscription components ί, Π ❹ only the conversion power is still, the sintering temperature range is also wide, so Please refer to Figure 2, which is a comparison of the open circuit voltage v:c of each group of conductive adhesives in the embodiment of the present invention. The so-called open circuit voltage is the condition that the solar cell is infinitely loaded with load A. The voltage is measured when the external current is disconnected. The output current at this time is 0. The open circuit voltage v〇c value is related to the maximum power point of the solar cell (maximum power p〇int, Mpp), that is, the maximum power that can be output... Generally speaking, when the solar cell can produce open circuit electricity The value ^ 〇 and the short-circuit current 18. The larger the value, the greater the power output it can produce. It can be seen from Figure 2 that the open circuit voltage voc obtained by each experimental group at each sintering temperature is about the same level. It is shown that the conductive paste of the present invention replaces the wrong component in the prior art with a snake to achieve the same open circuit voltage V as in the prior art. The performance is followed by reference to FIG. 3, which is a group of conductive adhesives in the embodiment of the present invention. The short-circuit current Isc is compared. The short-circuit current is the output current of the solar cell under no-load condition, that is, when the external circuit is short-circuited, and the voltage is 0. In an ideal state, the short-circuit current of the solar cell is equal to that generated when the light is illuminated. 13 200947718 The principle of solar energy is different from v°e. The value of short-circuit current 1se is related to the maximum power point (MPP) of the two mountains, which is the maximum power of monthly screening. Generally speaking, When the solar cell can produce: short: current! The larger the value of sc, the greater the power output it can produce. For example, =h 'comparative example!, „the short-circuit current ^ value is low sintering ((10): bottom) Low, about 7.7A level, which affects the direct = sintering temperature range. In contrast, the application of the example π in the range of burning "= 860 860 C ~ 960 C has a good short-circuit current two film The current performance of each sintering temperature is the same as or better than the short-circuit power of the commercially available products.
Isc表現。 接著參照圖四’其為本發明實施例中各組導電膠之填 充因子F.F比車又。填充因子F F值為最大功率點Mpp除以 開路電壓Voc和短路電流^之比例。對一個好的太陽能電 ❹池而言’除了要有高的開路電壓^與短路電流Ise外，還 要有盡篁接近1的填充因子，因為填充因子即表示最大輸 出功率與V。。、；^乘積接近之程度，越接近！其最大輸出 功率與理論上開路電壓vQe與短路電流^所能產生之功率 越相近。如圖四所示，比較例I、Π之填充因子在低燒結 /皿度下（86G c以下）非常低，大約只有3G%〜之間的水 準，亦顯示出了其有效燒結溫度範圍較窄之缺點。相較之 下應帛實施例I、以及商品化銀膠在燒結溫度^〜 960 C之間的|& ®都有著不錯的開路電壓值v。。，其值約在 200947718 65%〜75%之間不等。此實驗數據顯示導電膠以鉈與/或鉈氧 化物來取代習知技術中的錯成分可達更佳^真充因子表 現0Isc performance. Referring to Figure 4, it is a filling factor F.F of each group of conductive adhesives in the embodiment of the present invention. The fill factor F F is the ratio of the maximum power point Mpp divided by the open circuit voltage Voc and the short circuit current ^. For a good solar cell, in addition to having a high open circuit voltage and short-circuit current Ise, there must be a fill factor close to 1, because the fill factor is the maximum output power and V. . , ; ^ The closer the product is, the closer it is! The closer the maximum output power is to the theoretical open circuit voltage vQe and the short circuit current ^. As shown in Figure 4, the filling factor of Comparative Example I and Π is very low at low sintering/span (below 86G c), and is only about 3G%~, which also shows that the effective sintering temperature range is narrow. The shortcomings. In contrast, the & ® should have a good open circuit voltage value v between Example I and commercialized silver paste at a sintering temperature of ^ 960 C. . Its value is about 65%~75% between 200947718. This experimental data shows that the conductive paste replaces the wrong component in the prior art with bismuth and/or bismuth oxide.
以下之實施例中將描述導電膠之配置方法。須注意該 配置方法之步驟、成分比例、各實驗參數僅供以說明：發 明之實施方式，非欲就本發明之請求項加以限定。首先， 先製備導電膠之有機載體（vehicle)，其係將扣乃克重之乙 基纖維素樹脂（EC，ethyl cellulose)溶於5〜75克重的有機容 劑中，本實施例中使用之有機溶劑為二乙二醇丁^M bUtyl CarMt〇1) ’但並不限於僅能使用此類的有機溶劑，在 其他的實施例中，亦可使用其他_類溶劑或可溶纖維辛 樹脂類之有機溶劑。於本實施射，該溶劑之彿點約為 ㈣〜_t：之間。可在有機載體内添加少許的助劑 (additives) ’這些助劑可以是黏度調整劑、分散助劑 助劑、潤濕助劑等功能性添加劑。接著，取7〇〜95 ❹ 一般市售銀粉與10〜30克重的有機載體及WO克重的玻 璃炼塊混合，藉由使用三滾筒捏合機（Tk㈣π _幫助 散均勻，混合後所得到之糊狀或膏狀物即為導電膠。 :來用網印技術將導電膠塗佈於太陽能 二 =基材的表面有事先經過一氮化石夕抗反射處 面電場的銘膠則採用咖…膠。 :^膠，網印後的乾燥溫度與時間會隨著有 的有機溶劑與印刷番| 100韻。C之間，乾燥時斤不同’乾燥溫度約為 二夺間約為5〜3 0分鐘。正面與背面 15 200947718 導電膠的網印動作完成後，使用紅外線傳送帶式燒結爐對 導電膠進行燒結，其燒結之峰值溫度（peak temperature)可 在800〜l〇〇〇°C之間調整，燒結過後的導電膠會在基材的正 反面形成固態的電極。電極製作完成後，使用太陽能測試 機對太陽能電池進行電性的測試，以比較應用實施例與比 較例以及市面上商業化產品的導電膠效能。該太陽能測試 機台型號為QuickSun公司的120CA。在AM1 5G的太陽 狀態下來量測太陽能電池的電氣特性。 ❹【圖式簡單說明】 本發明可藉由說明書中若干較佳實施例與其詳細敘述 及隨附圖式得以瞭解。然而，此領域之技藝者應得以領會 所有本發明之較佳實施例係用以說明而非就本發明之申請 專利範圍予以限定，其中： 圖一為本發明實施例中各比較組導電膠轉換效率η對 燒結溫度之折線圖； ❹ 圖一為本發明實施例中各比較組導電膠開路電壓ν 對繞結溫度之折線圖；The configuration of the conductive paste will be described in the following examples. It should be noted that the steps, component ratios, and experimental parameters of the configuration method are for illustrative purposes only: the implementation of the invention is not intended to limit the claims of the present invention. First, an organic vehicle of a conductive paste is prepared by dissolving an ethyl cellulose (EC, ethyl cellulose) in an organic solvent of 5 to 75 grams, which is used in this embodiment. The organic solvent is diethylene glycol butyl group M bUtyl CarMt 〇 1) 'but not limited to the use of only such organic solvents, in other embodiments, other _ solvents or soluble fiber octyl resins may also be used. Organic solvents of the class. In this implementation, the solvent point of the solvent is about (four) ~ _t: between. A small amount of additives can be added to the organic vehicle. These additives can be functional additives such as viscosity modifiers, dispersing aids, and wetting aids. Next, take 7 〇 to 95 ❹. The general commercial silver powder is mixed with 10 to 30 gram of organic carrier and WO gram weight glass slab, and is obtained by mixing using a three-roller kneader (Tk(4) π _ The paste or paste is a conductive adhesive.: The screen printing technology is used to apply the conductive adhesive to the solar energy. The surface of the substrate has a gelatin in advance. : ^胶, drying temperature and time after screen printing will be accompanied by organic solvents and printing | 100 rhyme. C, when the drying is different, the drying temperature is about 2 to 3 minutes. Front and back 15 200947718 After the screen printing operation of the conductive adhesive is completed, the conductive paste is sintered using an infrared conveyor belt sintering furnace, and the peak temperature of the sintering can be adjusted between 800 〜 l 〇〇〇 ° C. The sintered conductive adhesive forms a solid electrode on the front and back sides of the substrate. After the electrode is fabricated, the solar cell is electrically tested using a solar tester to compare the application examples and comparative examples and commercialization on the market. Conductive adhesive performance. The solar test machine model is QuickCA's 120CA. The solar cell's electrical characteristics are measured in the solar state of AM1 5G. ❹ [Simplified illustration] The present invention can be implemented by several preferred embodiments. The detailed description and the accompanying drawings are intended to be understood by the claims of the claims FIG. 1 is a line diagram of the comparison between the conversion efficiency η of the comparison group and the sintering temperature of the comparative group in the embodiment of the present invention; FIG. 1 is a line diagram of the open circuit voltage ν versus the junction temperature of each comparative group of the comparative group in the embodiment of the present invention;
圖二為本發明實施例中各比較組導電膠短路電流Isc 對堍結溫度之折線圖；及 SC 圖四為本發明實施例中各比較組導電膠填充因子F F 對燒結溫度之折線圖。 .’ 【主要元件符號說明】 無 162 is a line diagram of the short-circuit current Isc of each comparative group of the conductive paste in the embodiment of the present invention; and FIG. 4 is a line diagram of the sintering temperature of the comparative group of the comparison group F F for the sintering temperature in the embodiment of the present invention. .’ [Main component symbol description] None 16