200947717 九、發明說明： 【發明所屬之技術領域】 本發明與一種導電膠有關，特別是關於一種用於太 能電池之導電膠’其係用以形成太陽能電池基材之背部電 【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 〇逐漸從能源概念產業中脫穎而出。目前國際油價節節高 漲，全球的石油資源有限，加上京都議定書對於廢氣減量 之壤保意識抬頭，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=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 f染問題。在替代性能源中，無論是太陽能、風能、地熱 此、生質能等’均為各先進國家共同推展之目帛，其中， 尤以太陽能之應用需求最為強烈。據太陽能研究機構 ❹s:iarbuzz調查顯示’在過去二十年内，太陽能光電的需求 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«量自讀年至鳩年，已從34gmw攀升至 1，74卿’5年之間的成長逾4倍’每年平均增幅約熟。 =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^電池⑽ar eell)是一種可將光能轉換成電能之 =般是以半導體材料’ #包含單晶⑦、多晶石夕及 非曰曰矽荨石夕基材，或是化合物半導體，如GaASGap、Inp、 5 200947717200947717 IX. Description of the Invention: [Technical Field] The present invention relates to a conductive adhesive, and more particularly to a conductive adhesive for a solar battery, which is used to form a back surface of a solar cell substrate. [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, international oil prices are rising steadily, and global oil resources are limited. Together with the Kyoto Protocol's awareness of waste protection for waste gas reduction, 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 energy sources to alleviate the problem of dyeing caused by traditional power generation methods. Among the alternative energy sources, whether it is solar energy, wind energy, geothermal energy, biomass energy, etc., are the common developments of advanced countries. Among them, the application demand for solar energy is the strongest. According to a survey by the solar research institute ❹s:iarbuzz, the demand for solar photovoltaics is on the rise in the past two decades. From the perspective of the installed capacity of solar photovoltaic systems, the global amount of self-reading from the year of reading to the following year has climbed from 34gmw to 1,74, and the growth of more than four times in the past five years has grown at an average annual rate. = See the role of solar power in the future of human energy use is becoming more and more important. The battery (10) ar eell is a kind of semiconductor material that can convert light energy into electric energy. # Contains single crystal 7, polycrystalline stone and non-stone substrate, or compound semiconductor, such as GaASGap, Inp, 5 200947717
AlGaAs等Π、V族元素化合物基材所製成。以矽基材而 言，業者一般作法是在Ρ型矽基材（p_type)i面的受光區域 摻雜磷原子（phosphorus)來形成一負電極區，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 SiNx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 (effieieney)。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，back surface fleld，即背鋁 電極）。鋁背面電場可減少少數載子（及電子e_、電洞h+) ^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。製作該銘背 ❹面電場最簡單的方式係為在石夕基材背面塗佈一層無膜並燒 結使銘原子擴散進入石夕晶片内，形成-高紹摻雜濃度 (Al-dopant)之 P+層。 处為I將太陽能電池所產生的電流導引出來成為可用之 電能’半導體基材的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，ί見今-般的金屬電極主要*利用網印技術㈣咖 6 200947717 printing)在太陽能電池的兩正反面印製出網狀電極結構。 所謂的網印電極備製，即係利用網印的方法，把導電金屬 漿料（如銀膠）依照所設計之圖形印刷在已經過摻雜的矽基 材上，並在適當的燒結條件下將導電金屬漿料中的有機溶 劑揮發，使金屬顆粒與表面的矽形成矽合金，形成矽材之 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: 降低電池整體的發電效率便為此領域之技術重點。一般而 言，金屬電極的膜厚約為1〇~25um，而正面金屬的網線 (【11^61'111^)寬度約為12〇〜2〇()11111。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。 此外，就一般太陽能電池矽基材而言（即非受光面）， 其背部電極結構包含了銀電極部分（網線電極部分）與鋁電 極部分（及上述之背部電場部分）。目前一般業界作法是先 ❹在石夕基材的背面先用網印方式印上銀電極圖形，之後在於 其上形成鋁電極層，如圖一所示。由於鋁的可銲性 (+ derability)很差’無法以直接焊接方式將各太陽能電池 模塊連結’故-般業者會使用數條焊接帶i (副― nbbon)輝在太陽能電池背部部分的銀電極區域上，使各發 電模塊間彼此電性連結整合。在圖一結構中，銀電極-石夕基 材介面2(即fire化_处層）以及結電極石夕基材介面3(即 BSF層）會於燒結過程中會形成共晶層而使其緊密接合，但 銀”紹之間不易形成共晶結構，其介面處易發生剝離現象 7 200947717 (:俨：A:使仵銀電極與鋁電極間產生裂隙讓太陽能電池 =下降。故此’❺了轉換效率測試外，太陽能電池 ^於1成後還須於背部進行焊接帶1之拉力測試以及銀 ^極與㈣極介面_離測試，以確保模組背部結構的穩 固。 綜上所言，可知除了形成PN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。 目前習知技術中的導電膠都是由金屬粉末(特別是銀粉)、 玻璃熔塊（glass frit)、有機載體（vehicle)、以及添加劑 (additive)等原料所組成。其成分、含量、比例、製程參數 等都會影響到最後電極產物之性能。以背面金屬電極為 例，除了上述有關焊接帶拉力大小與銀鋁電極介面剝離程 度外，其用以形成之導電銀膠與鋁膠優劣亦會直接影響到 其太陽能電池性能之轉換效率η、開路電壓Vce(open circuit voltage)、短路電流 lsc(short circuit current)、填充因子 F.F. ❹（fill factor)、串聯電阻 Rs(series resistance)、以及分流電阻 Rsh (shunt resistance)等，亦會決定有效之燒結溫度範圍Ts 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。 【發明内容】 鑑於上述習知技術之缺點，本發明提出了一種用於太 陽能電池之導電膠，其組成包含了一定比例範圍之銀粉、 鋁粉、玻璃熔塊、有機載體以及添加劑等，係用以形成太A substrate made of a ruthenium or a group V element compound such as AlGaAs. In the case of a ruthenium substrate, it is common practice for a light-receiving region on the i-plane of the 矽-type ruthenium substrate (p_type) to be doped with a phosphorus atom to form a negative electrode region, and a region on the back side where the light is not received is corresponding. Positive electrode end. The PN junction (PN juncti〇n) 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 SiNx film) to avoid energy loss caused by light reflection. Increasing the conversion efficiency of solar cells η (effieieney). In addition to the semiconductor substrate of the above solar cell, the industry generally forms an aluminum back surface electric field (BSF) on the back surface of the stone substrate after the completion of the PN interface. Aluminum electrode). The aluminum back surface electric field can reduce the probability of a few carriers (and electron e_, hole h+) ^ back recombination, can also be used as the back electrode of the battery, thereby improving the conversion efficiency of the solar cell. The easiest way to recite the electric field on the back surface is to coat a layer of film on the back of the stone substrate and sinter it to diffuse the Ming atoms into the stone wafer to form a high-doping concentration. (Al-dopant) P+ layer. I directs the current generated by the solar cell to become available power. 'The semiconductor substrate must also form a metal electrode to conduct current to the external current load terminal (load) ) However, the metal electrode on the light-receiving surface (ie, the front side) of the substrate blocks the light-receiving surface and hinders the absorption of sunlight. Therefore, the smaller the surface area of the solar cell of the solar cell, the better, so as to increase the light-receiving area of the solar cell. The current metal electrode mainly uses the screen printing technology (4) to print the mesh electrode structure on the front and back sides of the solar cell. The so-called screen printing electrode preparation method is to use the screen printing method. A conductive metal paste (such as silver paste) is printed on the already doped germanium substrate according to the designed pattern, and volatilizes the organic solvent in the conductive metal paste under appropriate sintering conditions to make the metal particles and the surface矽 forming a bismuth alloy, forming a good ohmic contact between the bismuth materials, and thus becoming a front and back metal electrode of the solar cell. However, the excessively thin electrode wire is liable to cause disconnection, or The increase in resistance reduces the conversion efficiency of the solar cell, so how to achieve thinning: And reducing the overall power generation efficiency of the battery is the technical focus of this field. In general, the thickness of the metal electrode is about 1 〇 ~ 25 um, The front metal wire ([11^61'111^) has a width of about 12〇~2〇()11111. The use of such technology to make solar cell electrodes has the advantages of automation, high productivity and low cost. In general, the solar cell is a substrate (ie, a non-light-receiving surface), and the back electrode structure includes a silver electrode portion (the wire electrode portion) and an aluminum electrode portion (and the back electric field portion described above). The silver electrode pattern is first printed on the back side of the Shixi substrate by screen printing, and then an aluminum electrode layer is formed thereon, as shown in FIG. Due to the poor solderability (+ derability) of aluminum, 'the solar cell modules cannot be connected by direct soldering'. Therefore, the manufacturer will use several solder ribbons i (sub-nbbon) to illuminate the silver electrodes on the back part of the solar cell. In the area, each power generation module is electrically connected to each other. In the structure of Fig. 1, the silver electrode-石夕 substrate interface 2 (i.e., the fire layer) and the junction electrode substrate 3 (i.e., the BSF layer) form a eutectic layer during the sintering process. Tightly joined, but it is not easy to form a eutectic structure between silver and shovel, and the interface is prone to peeling phenomenon. 7 200947717 (: 俨: A: A crack is formed between the yttrium silver electrode and the aluminum electrode to make the solar cell = drop. Therefore, '❺ In addition to the conversion efficiency test, the solar cell must be subjected to a tensile test of the soldering strip 1 and a silver electrode and a (four) pole interface _ separation test on the back to ensure the stability of the back structure of the module. In addition to the semiconductor substrate forming the PN junction, the most important material for making solar cells is the portion of the conductive paste. Currently, the conductive adhesives in the prior art are made of metal powder (especially silver powder) and glass frit ( Glass frit), organic vehicle (vehicle), and additives (additive) and other raw materials. Its composition, content, ratio, process parameters, etc. will affect the performance of the final electrode product. Take the back metal electrode as an example, except In addition to the relationship between the tensile strength of the soldering strip and the peeling degree of the silver-aluminum electrode interface, the advantages and disadvantages of the conductive silver paste and the aluminum adhesive used for forming the conductive strip directly affect the conversion efficiency η of the solar cell performance, the open circuit voltage Vce (open circuit voltage), Short circuit current lsc (short circuit current), fill factor FF fill (fill factor), series resistance Rs (series resistance), and shunt resistance Rsh (shunt resistance), etc., will also determine the effective sintering temperature range Ts and adhesion (adhesion) Therefore, how to adjust a conductive adhesive which can improve the performance of the above solar cells is the focus of current research and development in the industry. SUMMARY OF THE INVENTION In view of the above disadvantages of the prior art, the present invention proposes a solar cell. Conductive adhesive, the composition of which contains a certain proportion of silver powder, aluminum powder, glass frit, organic carrier and additives, etc.
S 200947717 陽能電池基材之背部電極以將太陽能電池產生之電流出。 在本發明-實施例中，其導電膠的玻璃炼塊組成中含 有叙（B〇與/絲氧化物，可增加導電膠燒結後其電極在石夕 基材上的黏著力。 在本發明另一實施例中，其比較了導電膠銀粉之粒徑 大小與形狀對於電極切基材上黏著力之影響。 ❹ 人^本發明又—實施例中，其比較了導電穋中玻璃熔塊 3量對於電極在矽基材上黏著力之影響。 在本發明又一實施例中，其比較;導電膠中紹粉含量 對於電極在矽基材上黏著力之影響。 本發明導電膠之製作方式亦於本發明書中揭示， 以網印方式印在半導體基材上，並於高 Μ爐中將其燒結成固態的電極。 電膠本發明之目的’為提供—種絲成分之太陽能電池導 ❹ 本發明之另一目的，兔接投 ^ , -Β ^為扣供一種太％能電池用導電 膠、、具有優良的光電轉換效率福電極黏著力。 導電目的’為提供上述本發明太陽能咖 以下述 '形式、目的、觀點、特徵及優點將隨著 顯，^ 例中詳細的描述及其伴隨之圖式而愈見明 …細郎描述與圖式僅用以述明本發明。而本發明之範 嘴將由隨附之專利請求項來定義。 树月之範 【實施方式】 9 200947717 此處本發明將針對發明具體實施例及其觀點加以詳細 描述，此類描述為解釋本發明之結構或步驟流程，其係供 以說明之用而非予以本發明申請專利範圍限制之實。因 此，除說明書中之具體實施例與較佳實施例外，本發明亦 可廣泛施行於其他不同的實施例中。 太陽能電池背面亦需導電膠，目的在於製作電極及連 接焊接帶（ribbon)以利電池串接。本發明所提出之導電膠係 ❹用以形成太陽能電池基材背面之銀電極（即非受光面），其 技術特徵在於改善該銀電極與石夕基材之間的拉力（銀電極 於石夕基材上之黏著力）、剝離程度（peeling，銀電極與紹電 ，面間剝離現象）、以及整體太陽能電池轉換效率”。黏 著力越兩，代表導電膠燒結後電極與石夕基材之間的接合越 好。為達上述目的，本發明之導電膠成分大體上包含了銀 粉（Ag)、鋁粉（Ai)、玻璃熔塊（frit)、有機載體、以 及各類添加劑（additives)。列表中關於拉力、剝離程度、轉 ❹換效率测試之細節亦會於系列的實施例中描述。 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（flake)、球狀（spheric^)或兩者之混合。於本發 明中，其銀粉粒徑約分佈在〇 5〜1〇 〇 μιη之間，下面的實 施例中將就不同的銀粒粒徑大小與形狀來作比較。於本發 明中’只要導電夥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 銀柘比例約佔整體導電膠重量5〇〜9〇wt %(重量百分比）為 佳。 200947717 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—甘醇一丁醚（Butyl Carbitol，DB)、α _ 松油醇（alpha· Terpineol)、Texanol成膜劑等；樹脂亦以二 種以上不同分子量的纖維素混合為佳，如乙基纖維素 (Ethyl cellui〇se，Ec)、木松香、聚丙烯腈或其混合物。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導電膠重量1〇〜25wt%為佳。 在玻璃熔塊方面，其組成中含有鉍Bismuth與/或鉍氧 化物出2〇3之成分，並還包含了其他如Si〇2、B2〇3、Al2〇3、S 200947717 The back electrode of the solar cell substrate to discharge the current generated by the solar cell. In the present invention-embodiment, the glass frit of the conductive paste contains a composition (B〇//SiO oxide), which can increase the adhesion of the electrode on the stone substrate after sintering of the conductive paste. In one embodiment, the effect of the particle size and shape of the conductive colloidal silver powder on the adhesion of the electrode-cut substrate is compared. ❹ 人^ In the present invention, in the embodiment, the amount of the glass frit 3 in the conductive crucible is compared. In the further embodiment of the present invention, the effect of the electrode on the adhesion of the electrode on the ruthenium substrate is also affected by the adhesion of the electrode on the ruthenium substrate. It is disclosed in the present invention that it is printed on a semiconductor substrate by screen printing and sintered into a solid electrode in a sorghum furnace. The purpose of the present invention is to provide a solar cell guide for the silk component. Another object of the present invention is that the rabbit receives a ^, -Β ^ for a conductive adhesive for a battery of too much energy, and has excellent photoelectric conversion efficiency, and the electrode adhesion is 'the purpose of providing the above solar energy coffee of the present invention. Shape , the purpose, the point of view, the features and the advantages will become more apparent as the detailed description in the example and the accompanying drawings thereof. The description and drawings are only used to illustrate the invention. It will be defined by the accompanying patent claims. [Embodiment] 9 200947717 The present invention will be described in detail with respect to the specific embodiments of the invention and the aspects thereof. The present invention is intended to be illustrative, and not to limit the scope of the invention. The invention may be widely practiced in various other embodiments. A conductive adhesive is also required on the back surface for the purpose of fabricating electrodes and connecting ribbons for battery serial connection. The conductive adhesive system of the present invention is used to form a silver electrode (ie, a non-light-receiving surface) on the back surface of a solar cell substrate. The technical feature is to improve the tensile force between the silver electrode and the stone substrate (adhesion force of the silver electrode on the stone substrate), peeling degree (peeling, silver electrode and Shao , the phenomenon of surface peeling), and the overall solar cell conversion efficiency. The more adhesive force, the better the bonding between the electrode and the stone substrate after sintering of the conductive paste. To achieve the above purpose, the conductive adhesive composition of the present invention is substantially It contains silver powder (Ag), aluminum powder (Ai), glass frit, organic carrier, and various additives. The details of the pull, peeling, and conversion efficiency tests in the list will also be included. It is described in the series of embodiments. Silver is a medium having excellent conductivity, and in the embodiment of the invention, the silver powder particles may be flake, spheric^ or a mixture of the two. In the present invention, The particle size of the silver powder is distributed between 〇5~1〇〇μιη, and the size and shape of the different silver particles will be compared in the following examples. In the present invention, the present invention is not particularly limited in its proportion as long as the content of the conductive silver component can achieve the object of the present invention. However, in the case of the embodiment, the silver ruthenium ratio is preferably about 5 〇 to 9 〇 wt% (% by weight) based on the total weight of the conductive paste. 200947717 In the embodiment of the present invention, the organic vehicle is prepared by mixing an organic solvent and a resin, and the organic solvent is preferably a mixture of two or more solvents, such as an alcohol ether, Butyl Carbitol. , DB), α _ terpineol (alpha· Terpineol), Texanol film former, etc.; resin is also better mixed with two or more different molecular weight cellulose, such as ethyl cellulose (Ethyl cellui〇se, Ec), Wood rosin, polyacrylonitrile or a mixture thereof. In the examples, the present invention is not particularly limited in its proportion as long as the content of the organic vehicle can attain the object of the present invention. However, in the case of the embodiment, the proportion of the conductive paste is preferably from about 1 to 25 wt%. In terms of glass frit, the composition contains bismuthumth and/or bismuth oxide as a component of 2〇3, and also contains other elements such as Si〇2, B2〇3, and Al2〇3.
Zn〇、Tl2〇3、Pb〇、Sr〇、Zr〇2、Κ2〇、Μ〗成分不同比例 之組合。就實施例而言，其比例含量佔約整體導電膠重量 1〜10wt %為佳。 此外，本發明導電膠亦可視各項需求添加一定含量的 ❹添加劑，如分散劑（dispersant)、流平劑（leve】Hng叫如。、 觸變劑（thiXotropic agent)、穩定劑（stabilizer)、黏度調節劑 Oascosity adjuster)、以及介面活性劑（surfactant)等助劑， 其含量約佔導電膠整體〇〜5wt%之間。此添加劑會在有機 載體做成後添加，其主要作用係為調整膠體之黏度且具有 1與粒子均勾分散的功能’亦可增進燒結後金屬粒子的 緊役度、導電度，故添加二種以上的添加物能達到更佳的 效果。 首先參照表一’其為本發明一實施例中設計以不同玻 200947717 璃組成與銀粒形狀來測試電極的拉力、轉換效率以及剝離 程度之實驗。該實驗依所使用的銀粒形狀（片狀、球形）分 成兩大組，每大組再依所使用之玻璃種類（玻璃II、III、IV、 V、VII)分成五個比較組，上述分組之目的在於比較導電膠 中銀粒之形狀以及玻璃熔塊之成分對整體導電膠性質造成 的影響。於本實施例中，片狀銀粒組所使用之銀粉為銀粉 III，球形銀粒組所使用之銀粉為銀粉VII，兩組銀粉之組 成比例皆佔整體導電膠69.3 wt%的重量百分比。有關各銀 ® 粉種類詳細之規格請參照表二，而各實驗組使用之玻璃熔 塊成分請參照表三。 組別 1 2 3 4 5 6 7 8 9 10 銀粒形狀 片狀 片狀 片狀 片狀 片狀 球形 球形 球形 球形 球形 銀粉種類69.3 wt% 銀粉m 銀粉m 銀粉瓜 銀粉ΙΠ 銀粉m 銀粉νπ 銀粉νπ 銀粉νπ 銀粉νπ 銀粉νπ 玻瑀種類4.20 wt% 玻瑀Π 玻璃IV 玻璃va 玻璃V 玻璃Μ 玻璃H 玻璃IV 玻璃vn 玻璃V 玻瑀ΒΙ 剝離程度 優 優 優 優 優 優 劣 優 優 劣 拉力(K) 1.34 2.68 2.36 0.82 2.27 3.14 3.29 4.12 3.21 4.08 效準(％) 14.95% 15.31% 15.20% 15.14% 15.44% 15.17% 15.20% 15.22% 15.23% 15.27% Q (表一) 銀粒種類 平均粒徑 純度 形狀 銀粒I 3.45 >99% 片狀 銀粒Π 5.06 >99% 片狀 銀粒m 3.88 >99% 片狀 銀粒IV 1.79 >99% 球形 銀粒V 2.8 >99% 球形 銀粒¥1 2.12 >99% 球形 銀粒W 5.51 >99% 球形 (表二） 12 200947717 玻璃種類 Si02 b2〇3 AI2O3 ZnO Bi2〇3 Τ1203 PbO SrO Zr02 K2o P2O5 玻璃Π 9.77% 5.33% 2.93% <1% <1% <1% 80,47% <1% 0.99% <1% <1% 玻璃m 4.84% 8.31% <1% 7.07% 76.99% <1% <1% 2.26% <1% <1% <1% 玻璃IV 9.82% 8.77% 5.21% <1% 60.81% <1% <1% 14.81% <1% <1% <1% 玻璃V 13.66% 4.67% 1.43% 39.02% <1% <1% 40.01% <1% 0.18% <1% <1% 玻璃VB 23.73% 8.39% 6.31% <1% 38.18% 20.40% <1% <1% <1% 1.77% <1% (表三） 如表三所示，本發明實施例使用了約佔整體導電膠 4.20 wt %比例的玻璃熔塊，其成分包含了 Bi203、Si02、 B2O3、AI2O3、ZnO、TI2O3、PbO、SrO、Zr〇2、K_2〇、P2O5 等各種金屬氧化物組成。表三中所示之重量百分比為該成 ® 分玻璃熔塊整體之比例。 復參照表一，從各組測試結果顯示，本實施例中導電 膠依使用的銀粒形狀與玻璃種類會對拉力（即電極的黏著 力）影響，但對於太陽能電池整體的轉換效率以及電極的剝 離程度也沒有顯著的關係。導電膠所使用的銀粉粒徑越 小，其所能達到的拉力值就越大，如圖二所示，平均粒徑 2·2μπι大小之球形銀粉可以達到近6牛頓（Ν)大小的拉力水 φ 準，相較之下，5.5 μιη大小之球形銀粉粒徑僅能達到約3.5 牛頓（Ν)的拉力水平。此外須注意的是，片狀銀粉所能達到 的拉力並不如球狀銀粉佳，如圖中的三角形標記所示，儘 管其片狀銀粉平均粒徑有3.8μιη之大小，但所能達到的拉 力水準僅有3 ·0牛頓（Ν)左右，較之5 ·5μπι粒徑大小之球形 銀粉還不如。同樣的實驗結果可以在圖三中觀察到，其為 本發明實施例中分別使用球形銀粉與片狀銀粉搭配不同玻 璃熔塊成分之拉力關係圖。從圖中可知，在使用相同玻璃 熔塊的情況下，球形銀粉所能達到的拉力值都較片狀銀粉 13 200947717 來的大’顯示呈球狀的銀粉經燒結後，其產生之背銀電極 内部結構較為密實，與矽基材的表面接合性佳。反之，片 狀銀粒為主體之導電膠經燒結後，其產生之背銀電極内部 結構空洞多，與石夕基材之間的接合性差。 另一方面就玻璃熔塊成分來看，可以觀察到使用玻璃 III、玻璃IV及玻璃VII之實驗組所能達到之拉力值較佳， 不論所搭配者為片狀或球形之銀粒。參照表三之成分，其 ❹共通點在於玻璃熔塊中含有高比例的鉍氧化物Bi2〇3，顯 示鉍或鉍氧化物成分有助於提升導電膠之拉力值。此外， 就片狀銀粒之實驗組而言，可發現使用玻璃π與玻璃V組 別的拉力表現特別差，其原因在於使用高含量的氧化鉛 PbO與氧化鋅ΖηΟ ,此兩金屬氧化物雖於太陽能電池其他 性能有所助益，但明顯會使電極所具備之拉力下降。 現在請參閱下表。表四所示者為本發明另一實施例中 針對銀粒形狀、玻璃熔塊含量以及助劑（即添加劑）添加與 〇 否所作的實驗比較。 組別 1 2 3 4 5 6 7 8 9 銀粒1 珍狀 片狀 片狀 片狀 球形 球形 球形 球形 球形 玻形 銀粉種類 / wt% 4•粒I 73.50% 65.10% 65.10% 銀粒VI 73.50% 72.30% 71.30% 70.30% 69.30% 65.10% 玻璃融塊 wt % 玻璃IV 0% 1.20% 2.20% 3.20% 4.20% 8.40% 玻璃V 8.4% 8.4% . m Η 無 無 有 有 有 有 有 有 有 _剝離程廑 劣 劣 優 優 優 優 優 優 優 拉力r>n 0.1 0.7 1.2 0.3 1.7 3.1 4.1 5.86 6.81 效聿f%、 14.50% 14.96% 15.17% 15.18% 15.21% 15.35% 15.25% 15.24% 14.88% (表四） 14 200947717 本實施例中分別使用銀粒ϊ片狀銀粉與銀粒¥1片狀銀 粉，其比例介於整體導電膠65.^73 5wt%之間，視其所使 用的玻璃熔塊含量而定。銀粒j與銀粒…詳細規格請參照 上面表二。使用球形銀粉之實驗組針對不同的玻璃熔塊含 量來作比較，從實驗數據可以發現當玻璃熔塊的含量越 多，所能達到的電極拉力值就越大，其關係如圖四所示。 在不使用任何玻璃熔塊的實驗條件下，所能達到之拉力值 幾乎接近零，而8 wt%含量之玻璃熔塊卻能達到6牛頓 ❹優異的拉力表現，顯示玻璃熔塊含量越高，背銀電極中溶 融玻璃更易與熔融的銀粒相互擴散，形成一導電的共晶結 構，分佈在熔融銀粒空隙及銀_矽介面及銀_鋁介面上，故 強化背銀電極結構，使得整體拉力值增加。須注意者，使 用的玻璃熔塊含量過多，會使焊接變得困難，且電阻值 增大。以本實施例而言，其玻璃含量最佳值應佔整體導電 膠1〜10 wt %的比例。 ❹ 另方面，在表四片狀銀粒的實驗組方面，可觀察到 助劑（additive)的添加與否對整體拉力值與電極之剝離現 象程度（peeling)有很大的影響。導電膠中若不添加任何的 助劑，其内部組成粒子如銀粒、鋁粒、玻璃熔塊等便無法 在有機載體中均勻分散，燒結後所形成之銀電極結構較為 鬆散，銀-鋁介面或銀-矽介面亦無法獲得良好的接合，故 其剝離程度與拉力表現都不佳，電池的轉換效率亦有明顯 的下降。就本發明實施例而言，其添加助劑含量應佔整體 導電膠0〜5 wt %的比例為佳。 15 200947717 接下來請參昭下矣，主 士 ’’、、 表五所示者為本發明又一會竑办丨 中=τ寡與電極拉力、轉換效率之關係= 1:=下ΓΓ銀粒形狀、含量以及玻璃溶塊種類、 換效率Μ▲呂⑽加的比例越高’所能達到的電池轉 敕馬，故可知於背部銀膠中添加紹粒有助於提升 正體太％旎電池之轉換效率。 電極所具備的拉力魏 —、’，·的含量越高， 用…！ 下降幅度非常嚴重。故實際應 ❷配士二 電極剝離及拉力之考量選擇鋁粒的最佳調 _/達到σ人所而之太陽能電池特性。就本發明實施 2而言，其銘粒含量以估整體導電膠0〜5 wt %的比例為 佳0 組別 I Π m 銀粒形肤 球形 球形 球形 銀粒粒徑 銀粒VI 69.30% 65.93% 64.93% 破璃融塊 玻璃IV 4.20% 4.95% ^4.95% 鋁粒wt % 0% ^3.37% 4.37% 拉力rm 5.86 3.23 1.5 效率⑽ 15.24% 15.35% 15.41% (表五） 儘管本發明上面列表與說明中有對其實施方式中各成 分之組成與含量作明確之定義，本領域之熟習技藝者須認 知者’上述本發明實施例中導電膠之各成分組成與含量並 #揭限於一特定的數值，其組成與含量範圍將視該成分能 否達到發明之目的來作定義。 200947717 下面之實施例中將描述導電膠之配製方法。須注音該 配置方法之步驟、成分比例、各實驗參數僅供以說明本發 明之實施方式’非欲就本發明之請求項加以限定。 配製裎庠 首先，先將一定成分比例之鋁粒、玻璃熔塊加到有機 載體中，用混合器（mixer)先行預混。該有機載體可為乙基 纖維素樹脂（EC, ethyl cellul〇se)與二乙二醇丁醚（DB，A combination of different ratios of Zn〇, Tl2〇3, Pb〇, Sr〇, Zr〇2, Κ2〇, and Μ. For the examples, the proportion of the conductive paste is preferably from 1 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 bismuth additives, such as a dispersant, a leveling agent (leve), a thiXotropic agent, a stabilizer, and a stabilizer. A viscosity modifier (Oascosity adjuster), and an surfactant (surfactant) and other additives, the content of which accounts for about 5% to 5% by weight of the conductive paste. The additive is added after the organic carrier is formed, and its main function is to adjust the viscosity of the colloid and have the function of 1 and the particles are dispersed, and the adhesion and conductivity of the metal particles after sintering can be improved, so two kinds of additives are added. The above additives can achieve better results. Referring first to Table 1, the experiment of designing the tensile strength, conversion efficiency, and peeling degree of the electrode by using different glass compositions and silver grain shapes in an embodiment of the present invention. The experiment is divided into two groups according to the shape of the silver particles (sheet, sphere) used, and each group is divided into five comparison groups according to the type of glass used (glasses II, III, IV, V, VII). The purpose is to compare the shape of the silver particles in the conductive paste and the effect of the composition of the glass frit on the properties of the overall conductive paste. In the present embodiment, the silver powder used in the flake silver group is silver powder III, and the silver powder used in the spherical silver group is silver powder VII, and the composition ratio of the two groups of silver powder accounts for 69.3 wt% of the total conductive rubber. Refer to Table 2 for the detailed specifications of each silver ® powder type, and refer to Table 3 for the glass frit components used in each experimental group. Group 1 2 3 4 5 6 7 8 9 10 Silver-grained flake-shaped flake-like flakes-shaped spherical spherical spherical spherical spherical silver powder type 69.3 wt% Silver powder m Silver powder m Silver powder melon silver powder Silver powder m Silver powder νπ Silver powder νπ Silver powder Νπ Silver powder νπ Silver powder νπ Glass 瑀 type 4.20 wt% Glass 瑀Π Glass IV glass va Glass V glass Μ Glass H glass IV glass vn glass V glass 剥离 Excellent degree of separation Excellent and excellent excellent and bad good and bad tension (K) 1.34 2.68 2.36 0.82 2.27 3.14 3.29 4.12 3.21 4.08 Effect (%) 14.95% 15.31% 15.20% 15.14% 15.44% 15.17% 15.20% 15.22% 15.23% 15.27% Q (Table 1) Silver Particle Type Average Particle Size Purity Shape Silver Particles I 3.45 >99 % flake silver Π 5.06 > 99% flake silver m 3.88 > 99% flake silver IV 1.79 > 99% spherical silver V 2.8 > 99% spherical silver ¥1 2.12 > 99% Spherical silver particles W 5.51 > 99% spherical (Table 2) 12 200947717 Glass type Si02 b2〇3 AI2O3 ZnO Bi2〇3 Τ1203 PbO SrO Zr02 K2o P2O5 Glass crucible 9.77% 5.33% 2.93% <1% <1% <;1% 80,47% <1% 0.99% <1% <1% glass m 4.84% 8.31% <1% 7.07% 76.99% <1% <1% 2.26% <1% <1% <1% Glass IV 9.82% 8.77% 5.21% <1% 60.81% <1% < 1% 14.81% <1% <1% <1% Glass V 13.66% 4.67% 1.43% 39.02% <1% <1% 40.01% <1% 0.18% <1% <1% Glass VB 23.73% 8.39% 6.31% <1% 38.18% 20.40% <1% <1% <1% 1.77% <1% (Table 3) As shown in Table 3, the present invention used The glass frit accounts for about 4.20 wt% of the total conductive paste, and its composition includes various metal oxides such as Bi203, SiO 2 , B 2 O 3 , AI 2 O 3 , ZnO, TI 2 O 3 , PbO, SrO, Zr 〇 2, K 2 〇, and P 2 O 5 . The weight percentages shown in Table 3 are the ratio of the integral to the glass frit. Referring to Table 1, the test results of each group show that the shape of the silver particles and the type of glass used in the present embodiment affect the tensile force (ie, the adhesion of the electrode), but the conversion efficiency of the solar cell as a whole and the electrode There is also no significant relationship between the degree of peeling. The smaller the particle size of the silver powder used for the conductive paste, the greater the tensile force it can reach. As shown in Figure 2, the spherical silver powder with an average particle size of 2·2μπι can reach a tension water of approximately 6 Newtons. φ is quasi-, in contrast, the particle size of 5.5 μιη spherical silver powder can only reach a tensile level of about 3.5 Newtons (Ν). In addition, it should be noted that the tensile force that the flake silver powder can achieve is not as good as the spherical silver powder, as shown by the triangular mark in the figure, although the average particle size of the flake silver powder is 3.8 μηη, the tensile force can be achieved. The level is only about 3. 0 Newtons (Ν), which is not as good as the spherical silver powder with a particle size of 5 · 5μπι. The same experimental results can be observed in Fig. 3, which is a tensile force diagram of the use of spherical silver powder and flake silver powder in combination with different glass frit components in the examples of the present invention. It can be seen from the figure that in the case of using the same glass frit, the tensile force that can be achieved by the spherical silver powder is higher than that of the silver powder 13 of the slab silver powder 13 200947717, after the sintered silver powder is sintered, the back silver electrode is produced. The internal structure is relatively dense and has good adhesion to the surface of the tantalum substrate. On the contrary, after the conductive paste of the main body of the silver plate is sintered, the inner structure of the back silver electrode is large, and the bonding property with the stone substrate is poor. On the other hand, as far as the glass frit component is concerned, it can be observed that the tensile force value which can be achieved by the experimental group using the glass III, the glass IV and the glass VII is good, regardless of whether it is a sheet or a spherical silver particle. Referring to the composition of Table 3, the common point is that the glass frit contains a high proportion of niobium oxide Bi2〇3, which indicates that the niobium or tantalum oxide component contributes to the tensile strength of the conductive paste. In addition, in the experimental group of flake silver particles, it was found that the tensile strength of the glass π and the glass V group was particularly poor because the high content of lead oxide PbO and zinc oxide ΖηΟ were used, although the two metal oxides were It is helpful for other properties of the solar cell, but it obviously reduces the tensile force of the electrode. Please refer to the table below now. Table 4 shows an experimental comparison of silver particle shape, glass frit content, and additive (i.e., additive) addition and enthalpy in another embodiment of the present invention. Group 1 2 3 4 5 6 7 8 9 Silver grain 1 Jane-shaped flake-like flakes Spherical spherical spherical spherical spherical silver powder type / wt% 4•Particle I 73.50% 65.10% 65.10% Silver grain VI 73.50% 72.30 % 71.30% 70.30% 69.30% 65.10% Glass melt wt % Glass IV 0% 1.20% 2.20% 3.20% 4.20% 8.40% Glass V 8.4% 8.4% . m Η Nothing Nothing There are some _ peeling 廑Inferior superior and excellent excellent and excellent excellent excellent rally r>n 0.1 0.7 1.2 0.3 1.7 3.1 4.1 5.86 6.81 Effectiveness f%, 14.50% 14.96% 15.17% 15.18% 15.21% 15.35% 15.25% 15.24% 14.88% (Table 4) 14 200947717 This implementation In the examples, silver flaky silver powder and silver granules were used, respectively, and the ratio was between 65.^73 wt% of the total conductive paste, depending on the glass frit content used. Silver grain j and silver grain... For detailed specifications, please refer to Table 2 above. The experimental group using spherical silver powder was compared for different glass frit contents. From the experimental data, it can be found that the more the glass frit content, the larger the electrode pull value can be achieved, and the relationship is shown in Fig. 4. Under the experimental conditions without using any glass frit, the tensile force can be almost zero, and the 8 wt% glass frit can achieve an excellent tensile performance of 6 Newtons, indicating that the glass frit content is higher. The molten glass in the back silver electrode is more easily diffused with the molten silver particles to form a conductive eutectic structure, which is distributed in the molten silver grain gap and the silver-germanium interface and the silver-aluminum interface, so that the back silver electrode structure is strengthened, so that the whole The pull value increases. It should be noted that the excessive amount of glass frit used will make welding difficult and the resistance value will increase. In the present embodiment, the optimum glass content should be in the proportion of 1 to 10 wt% of the entire conductive paste. ❹ On the other hand, in the experimental group of the four-plate silver particles, it can be observed that the addition of the additive has a great influence on the overall tensile force value and the peeling degree of the electrode. If no additives are added to the conductive paste, the internal constituent particles such as silver particles, aluminum particles, glass frits, etc., cannot be uniformly dispersed in the organic carrier, and the silver electrode formed after sintering is loosely structured, and the silver-aluminum interface is loose. Or the silver-tank interface can not get a good joint, so the degree of peeling and tensile performance are not good, and the conversion efficiency of the battery is also significantly reduced. For the embodiment of the present invention, the additive additive content should preferably be 0 to 5 wt% of the total conductive adhesive. 15 200947717 Next, please refer to the next slogan, the main person '', and the five shown in the table are the other side of the invention = = = τ oligo with electrode pull, conversion efficiency = 1: = ΓΓ silver Shape, content, and type of glass dissolver, conversion efficiency Μ ▲ Lu (10) plus the higher the ratio of the battery can be reached, so it can be seen that adding granules to the back silver paste helps to improve the body too% 旎 battery Conversion efficiency. The higher the tensile strength of the electrode, the higher the content of the electrode, the use of...! The decline is very serious. Therefore, the actual adjustment of the aluminum electrode should be selected according to the consideration of the peeling and pulling force of the two electrodes, and the solar cell characteristics of the σ person should be achieved. For the implementation of the present invention 2, the content of the granules is estimated to be 0 to 5 wt% of the total conductive paste. 0 Group I Π m Silver granules Spherical spherical spherical silver granules Silver granules VI 69.30% 65.93% 64.93% broken glass frit glass IV 4.20% 4.95% ^4.95% aluminum grain wt% 0% ^3.37% 4.37% tensile force rm 5.86 3.23 1.5 efficiency (10) 15.24% 15.35% 15.41% (Table 5) Despite the above list and description of the present invention There is a clear definition of the composition and content of each component in the embodiment, and those skilled in the art will recognize that the composition and content of each component of the conductive paste in the above embodiment of the present invention are limited to a specific value. The composition and content range will be defined by whether the component can achieve the purpose of the invention. 200947717 The following describes the preparation method of the conductive paste. The steps of the configuration method, the proportions of the components, and the experimental parameters are only intended to be illustrative of the embodiments of the present invention, and are not intended to limit the claims of the present invention. Preparation of 裎庠 First, a certain proportion of aluminum particles and glass frit are added to the organic carrier, and premixed with a mixer. The organic vehicle may be an ethyl cellulose resin (EC, ethyl cellul〇se) and diethylene glycol butyl ether (DB,
Carbh〇1)之混合物，但並不限於僅能使用此類的有機溶 劑。在其他的實施例中，亦可使用其他醇醚類溶劑或可溶 纖維素樹脂類之有機溶劑，如木松香、聚丙稀腈、松油醇 等。該有機載體内亦可添加一定比例的添加劑或助劑 (▲ ditives)這些添加劑可以是黏度調整劑、分散助劑、觸 變助劑、潤濕助劑等功能性添加劑。於本實施例中，該玻 璃熔塊可含有許多氧化物玻璃成分，其組成與比例由實驗 者自行決定。在第一次預混後，接著將銀粒添加到已預混 ❹的混合物中，再用混合器加以預混。預混完成後，包含銀 粒二鋁粒、玻璃熔塊、有機載體以及添加劑之混合物會使 二三滾筒捏合機（3_r〇llmiu)幫助分散研磨均勻混合後所 得到之糊狀或膏狀物即為導電膠。 一印刷藉序 ^ 導電膠/ttj σ元成後，接著網印方式（screen printing)將 、導電膠印刷在石夕基材背面，此即石夕基材之背部銀電極部 刀老。I5銀膠完成網印後，再分別於矽基材正面與背面印 面銀電極與背面銘電極。在本發明實施例中，其正面 17 200947717 銀電極採用DuP〇nt PV-145銀膠，背面鋁電極採用gsc A168铭膠。電極印製完成後，整個矽基材會被置於—棋箱 中乾燥。對於不同性能的導電膠，其網印後所須之乾燥溫 度與時間會隨著有機載體使用之有機溶劑以及印刷重量而 有所不同。在本實施例中，其乾燥溫度設定在150〜2〇〇 C ’乾燥時間為5〜15分鐘。 燒結裎序 乾燥步驟元成後，將整個碎基材置於一紅外線傳送帶 〇 $燒結爐來對導電膠進行燒結製程。與本實施财，其燒 、”《之峰值溫度（peak temperature)可在6〇〇〜8⑼。C之間做調 整，燒結過後的導電膠會在基材的正反面形成固態的電極 並與矽基板間產生接合。 量測鋥序 拉力測試（黏著力測試）： 電極製作完成後，將—錫條（在本發明中，其成份為锡 ❺鉛合金披覆在銅片外表’截面寬約18~2mm，其錫鉛比例 為60:40)用烙鐵焊接在石夕基材背部銀電極上，絡鐵頭使用 斜刀口形狀，其焊接溫度為32〇〜35〇t，移動速度為 1 5cm/s。疋成焊接後，利用拉力機設定丨。角、速度為 120〜360mm/s之測試條件來測量背銀電極之拉=值 (adhesion strength) ° 剝離測試（peeling test): 使用3M 600 Scotch透明膠帶為測試帶，將膠帶以順 向方式緊密黏著於包含背銀電極與背鋁電極之表面區域， 200947717 其後將膠帶以9〇。請^。撕起後，觀察其剝落 圖五a, b所不。若背銀電極與背銀電極重聂 剝落並殘留在膠帶上，即未通過剝離測試，：圖五之二層會 反之’則通過測試，如圖五a所示。 不 轉換效率測試： 使用太陽能測試機對製作出之太陽能模 試，其測試條件為在光源照射強度AM1.5G的環：= ❹ 使用之太陽能測試機台型號為QuiekSun公司的i2〇CA。 【圖式簡單說明】 本發明可藉由㈣#巾若干較佳實施例與其詳細敛述 及隨附圖式得以瞭解。然而，此領域之技藝者應得以領會 有本發月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背部電極之示意圖； 圖二為本發明實施例甲銀粉粒徑與拉力之關係圖； ❹ 圖二為本發明實施例中各組不同玻璃熔塊與拉力之關 係圖； 圖四為本發明實施例中各玻璃熔塊含量與拉力之關係 圖；以及 圖五為本發明實施例中剝離測試結果之圖像。 【主要元件符號說明】 1 焊接帶 2 介面 3 介面 19A mixture of Carbh® 1), but is not limited to the use of only such organic solvents. In other embodiments, other alcohol ether solvents or organic solvents such as soluble cellulose resins such as wood rosin, polyacrylonitrile, terpineol, and the like may also be used. The organic carrier may also be added with a certain proportion of additives or auxiliaries (▲ ditives). These additives may be functional additives such as viscosity modifiers, dispersing aids, thixotropic auxiliaries, and wetting aids. In this embodiment, the glass frit may contain a plurality of oxide glass components, the composition and proportion of which are determined by the experimenter. After the first premix, the silver particles are then added to the premixed mixture and premixed with a mixer. After the pre-mixing is completed, the mixture containing the silver-coated aluminum particles, the glass frit, the organic carrier and the additive enables the two-three roller kneader (3_r〇llmiu) to help the dispersion to be uniformly mixed and the paste or paste obtained. It is a conductive adhesive. A printing order ^ conductive adhesive / ttj σ element, followed by screen printing (screen printing), conductive adhesive printed on the back of the stone substrate, which is the back of the stone substrate of the silver electrode. After the I5 silver paste is screen printed, the silver electrode and the back electrode are printed on the front and back sides of the substrate. In the embodiment of the present invention, the front surface of the 2009 20091717 silver electrode is DuP〇nt PV-145 silver paste, and the back aluminum electrode is gsc A168 gelatin. After the electrode is printed, the entire substrate is placed in a chess box to dry. For conductive pastes of different properties, the drying temperature and time required for screen printing will vary depending on the organic solvent used in the organic carrier and the printing weight. In the present embodiment, the drying temperature is set at 150 to 2 〇〇 C 'the drying time is 5 to 15 minutes. Sintering process After the drying step is completed, the entire broken substrate is placed in an infrared conveyor belt 烧结 $ sintering furnace to sinter the conductive paste. With this implementation, the "peak temperature" can be adjusted between 6 〇〇 8 (8) and C. The sintered conductive paste will form a solid electrode on the front and back sides of the substrate and Bonding occurs between the substrates. Measurement of the tensile test (adhesion test): After the electrode is fabricated, the tin bar (in the present invention, the composition of the tin-lead-lead alloy is coated on the outer surface of the copper piece) has a section width of about 18 ~2mm, the tin-lead ratio is 60:40) Soldering on the silver electrode on the back of the stone substrate with a soldering iron. The angle of the iron head is in the shape of a diagonal knife. The welding temperature is 32〇~35〇t, and the moving speed is 15cm/ s. After welding, use a tensile machine to set 丨. Angle and speed are 120~360mm/s test conditions to measure the tensile strength of the back silver electrode. Peeling test: Use 3M 600 Scotch The scotch tape is the test tape, and the tape is closely adhered to the surface area including the back silver electrode and the back aluminum electrode in a forward direction, and then the tape is 9 2009 after 200947717. Please, after tearing up, observe the peeling off figure 5a, b. No. If the back silver electrode and the back silver electrode Nie peeled off and left on the tape, that is, it did not pass the peel test. The second layer of Figure 5 will be reversed, then it will pass the test, as shown in Figure 5a. No conversion efficiency test: Solar test with solar tester. The test condition is a ring with a light source irradiation intensity of AM1.5G: = ❹ The solar test machine model used is QuiekSun's i2〇CA. [Simplified Schematic] The present invention can be implemented by (4) #巾# The detailed description and the accompanying drawings are to be understood, and the skilled in the art should be able to understand that the preferred embodiment of the present invention is intended to be illustrative and not to limit the scope of the invention. 1 is a schematic view of a back electrode in an embodiment of the present invention; FIG. 2 is a relationship diagram between particle size and tensile force of a silver powder according to an embodiment of the present invention; ❹ FIG. 2 is a relationship diagram of different glass frits and tensile force of each group in the embodiment of the present invention; 4 is a diagram showing the relationship between the content of each glass frit and the tensile force in the embodiment of the present invention; and FIG. 5 is an image of the peeling test result in the embodiment of the present invention. A welding interface with 3 interface 19 2