201002417 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種保護塗層塗佈方法，尤指一種長晶用掛鋼之保護 塗層塗佈方法。 【先前技術】 應用於太陽能電池之矽晶圓材料可分為單晶與多晶兩種，石夕晶圓材料 於現在太陽能產業中市場佔有率高達90%。目前可利用CZ方式長單晶，或 者利用DSS與HEM方法製造單方向柱狀多晶石夕，上述長晶方法皆須使用陶 瓷坩鍋材料盛裝高溫液態矽金屬，一般坩鍋材料是採用熔融石英 Quaratz)或石墨材料，當使用石墨坩鍋時，高溫矽金屬易與石墨反應生成 碳化矽，而影響到矽晶品質。另當使用熔融石英坩鍋時，亦會因石英坩鍋 内的玻璃相（Vitreous silica)在高溫過程漸漸轉變為結晶相 (Devitrification) ’在坩鍋表面生成島狀的白矽石（Crist〇balite)，於長 晶過程中可能溶人娜湯，導致神凝固後生成差排。使用石英馳所產 生的另一個問題是’當長晶溫度超過石夕熔點時，石英掛鋼會因玻璃相軟化， 因而產生變形’所以常使用耐熱石墨板支揮_，由於高溫液態石夕 金屬會與石英賴反應’生成氧化雜氧，氧化⑪會與耐熱石墨板起反應， 生成碳化雜-氧化碳’而—氧化碳雜魏魅祕與氧切，而溶入 石夕金屬的碳與氧’會對太陽能電池的轉換效率造成不利的影響，尤其是對 =向性柱狀多辦’其高溫⑪金細於石英義中顧，易_金屬與石 英職在高溫長賴發生界面反應，使·#躲面發生咬觀象，並 於降溫冷卻過程因膨脹係數的差異所形成的應力，造成獅與禱鍵的破裂。 因此’ -般常於石英掛鋼内壁施加—層不與高溫石夕金屬反應的塗層， 利用此塗層簡_金屬舆石英藝的反應，並改切金雜石英賴咬 模問題H«料文獻及專觀及不_塗層騎與猶，最廣泛被 201002417 如美國專利第4515755號，Shuitsu Matsuo提出以CVD氣相析出方式 披覆一層氮化矽塗層於一石英坩鍋，塗層含有2〇%以上的p相或含8〇%以 上的α相，以避免高溫熔解矽金屬時，石英坩鍋中的氡溶入碎熔湯中，進 而影響矽晶的性質。 另如美國專利第4741925號，Chaudhuri提出以化學沉積方式通入反應 式氣體在1250 C形成α相氮化石夕塗層，但此上述兩種鍍膜方式的增厚速度 很慢，且鍍膜設備昂貴，造成製程成本高，一般僅是應用在薄膜塗層。 另如美國專利第5431869號’ Kumar研究在長晶模具上塗佈含有機黏結 劑（如alcohol, esters, acetone, and benzene)與水的氮化矽漿體，以於 長晶模具形成一塗層，有效保護模具及使矽錠易於脫模。另更於矽中加入 少量CaF2或CaCh，由於它不與純矽反應，會被石夕推至模壁，可有效阻止 矽液與模具間的反應’但由於齒化物會侵蝕氮化矽塗層，在長時間長晶過 程易導致石夕中雜質含量提高。 另美國專利第6,165,425號，Horst Lange使用氮化石夕粉末，其中氧含 量為0. 3至1. 5 wt%，鹼金屬（1-100 ppm)或鹼土族（koo ppm)、氟化 物（10-1000 ppm)、氣化物（30-1000 ppm)與碳含量（5〇_丨5〇〇 ppm)控 制在最小量，其他金屬元素含量亦同，如Fe、Cr、Co、Ni、W、Ti等等， 其個別含量最好在1-100 ppm，此法適用於非鐵合金(&、A1、Ge、Ti)的溶 解’尤其是石夕合金。同時為改善其塗層與时鋼結合度，可於其適當流體性 質下選擇加入organosilane、silicic acid esters、p〇ly〇is、polyvinyl alcohols、acrylates 及水或水與 hydrophilic 溶劑 〇!·增厚劑(celM〇se 衍生物）’然後再以塗刷或喷、Squirting、浸的方式製作塗層，之後，最 好在大於100°C下乾燥，並於500至700X下燒結一段適當時間，以作脫酯 燒結，但此專利並未詳細揭露其塗佈方法。 另美國專利第6491971號，Michael A Costantini提出坩鋼用離模塗 層系統，使用氮化石夕加入Cellulose ether與去離子水(di water)及消泡 劑’以高速攪拌混合，調至黏度為Zahn#2 60秒的漿體，利用商業用的嘴 201002417 塗設備，均勻塗佈於坩鍋上，並經1095T 3小時燒結，經Dur〇meter硬度 測量僅從89 Shore A提高至95 Shore A，其缺點是燒結後塗層強度較弱， 坩鍋進矽料或移動過程，會因碰撞或刮傷坩鍋產生塗層剝落，形成矽錠的 雜質。 此外，美國專利第6479108號，Alleppey V. Hariharant利用安定化 氧，锆或 Magnesium zirconate (MgZr〇3)或 BaHum zirc〇nate (BaZra)經 由间速電漿傭至;5英賴⑽絲，由於随粉體在高溫熔解或軟化， 因而彼覆在賴表面’作為祕熔融賴石英職反應，簡免造成污染 單晶石夕衫⑽’但在賴倾雜，由於高溫毅加熱石英職使得溫 度大幅上升，會導·致陷>!播相田總儿鹿上,,., a _ _ ..201002417 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD The present invention relates to a protective coating coating method, and more particularly to a protective coating coating method for long crystal steel. [Prior Art] The wafer materials used in solar cells can be divided into single crystal and polycrystalline. The market share of Shixi wafer materials in the solar industry is as high as 90%. At present, it is possible to use a CZ long single crystal or a DSS and HEM method to produce a unidirectional columnar polycrystalline stone. The above-mentioned long crystal method must use a ceramic crucible material to hold a high temperature liquid bismuth metal, and the general crucible material is fused silica. Quaratz) or graphite material, when using graphite crucibles, high temperature bismuth metal easily reacts with graphite to form niobium carbide, which affects the quality of twinning. In addition, when a fused silica crucible is used, the Vitreous silica in the quartz crucible is gradually converted into a crystalline phase (Devitrification) at the high temperature process to generate island-like chalk on the crucible surface (Crist〇balite). ), in the process of crystal growth may dissolve the Na Na soup, causing the god to coagulate and produce a poor row. Another problem with the use of quartz is that 'when the temperature of the crystal growth exceeds the melting point of Shishi, the quartz steel will be softened due to the softening of the glass phase, so the heat-resistant graphite plate is often used _, due to the high temperature liquid Shixia metal Will react with quartz lysate to generate oxidized hetero-oxygen, oxidation 11 will react with heat-resistant graphite sheet to form carbonized carbon-oxidized carbon - and carbon oxides will be secreted and oxygen-cut, and carbon and oxygen dissolved in Shixia metal 'The solar cell's conversion efficiency will be adversely affected, especially for the = directional columnar multi-do's high temperature 11 gold thinner than the quartz right, easy _ metal and quartz jobs in the high temperature long-term interface reaction, so that ·#The hiding phenomenon occurs when the hiding surface occurs, and the stress caused by the difference in the expansion coefficient during the cooling and cooling process causes the lion and the prayer key to rupture. Therefore, it is often applied to the inner wall of quartz steel. The coating does not react with the high temperature stone metal. The reaction of the coating is simplified, and the reaction of the quartz crystal is changed. Literature and monographs and not-coating and jujube, the most widely used by 201002417, such as US Patent No. 4515755, Shuitsu Matsuo proposed to coat a layer of tantalum nitride coating in a quartz crucible by CVD vapor deposition. 2% or more of the p phase or more than 8% of the α phase, in order to avoid melting the base metal at a high temperature, the bismuth in the quartz crucible is dissolved in the crushed soup, thereby affecting the properties of the twin. In addition, as in U.S. Patent No. 4,741,925, Chaudhuri proposes to form a phase-by-phase nitriding coating at 1250 C by chemical deposition into a reactive gas, but the thickening speed of the above two coating methods is very slow, and the coating equipment is expensive. The process cost is high and is generally only applied to the film coating. In addition, U.S. Patent No. 5,431, 869, Kumar Research, coats a long-crystal mold with a tantalum nitride slurry containing an organic binder (such as alcohol, esters, acetone, and benzene) and water to form a coating on the crystal growth mold. It effectively protects the mold and makes the bismuth ingot easy to release. In addition, a small amount of CaF2 or CaCh is added to the crucible. Since it does not react with pure hydrazine, it will be pushed to the mold wall by Shi Xi, which can effectively prevent the reaction between the mash and the mold. In the long-term crystal growth process, it is easy to cause the impurity content in Shi Xi to increase. In U.S. Patent No. 6,165,425, Horst Lange uses a nitriding powder having an oxygen content of 0.3 to 1.5 wt%, an alkali metal (1-100 ppm) or an alkaline earth (koo ppm), fluoride (10- 1000 ppm), vapor (30-1000 ppm) and carbon content (5〇_丨5〇〇ppm) are controlled to a minimum, and other metal elements are also the same, such as Fe, Cr, Co, Ni, W, Ti, etc. Etc., the individual content is preferably in the range of 1-100 ppm. This method is suitable for the dissolution of non-ferrous alloys (&, A1, Ge, Ti), especially the alloy. At the same time, in order to improve the adhesion of the coating to the steel, it is possible to select organosilane, silicic acid esters, p〇ly〇is, polyvinyl alcohols, acrylates and water or water and hydrophilic solvent under the appropriate fluid properties! (celM〇se derivative) 'The coating is then applied by brushing or spraying, Squirting, dipping, and then preferably dried at greater than 100 ° C and sintered at 500 to 700 X for a suitable period of time. De-esterification sintering, but this patent does not disclose its coating method in detail. In addition to U.S. Patent No. 649,1971, Michael A Costantini proposed a die-coating system for bismuth steel, using Cellulose ether with deionized water (di water) and defoamer to mix at high speed and adjust to a viscosity of Zahn. #2 60 seconds of slurry, using commercial nozzle 201002417 coating equipment, evenly coated on the crucible, and sintered at 1095T for 3 hours, the Durummeter hardness measurement only increased from 89 Shore A to 95 Shore A, The disadvantage is that the strength of the coating after sintering is weak. When the crucible is sucked or moved, the coating may peel off due to collision or scratching of the crucible to form impurities of the crucible. In addition, U.S. Patent No. 6,479,108, Alleppey V. Hariharant utilizes stabilized oxygen, zirconium or Magnesium zirconate (MgZr〇3) or BaHum zirc〇nate (BaZra) via a meso-speed plasma; 5 Yinglai (10) silk, due to The powder melts or softens at high temperature, so it covers the surface of the Lai's surface as a secret reaction. It is easy to cause pollution of the single crystal stone (10)'. However, due to the high temperature, the quartz temperature makes the temperature rise sharply. , will guide · trap >! broadcast phase of the total child deer,,., a _ _ ..
，出有效降低多轉長晶污㈣方式有，如改善氮化賴構性質以減少長 晶過程氮化⑦的分解(DeeQ_sitiQn)贿低獅表面積無積比例(如增 鋼Size)由以往專利文獻如美國專利第6165425號及美國專利第 _1971號所述的氮化矽燒結溫度僅在5〇〇1〇9 粉末在常壓燒結時，須加溫至.臟，才會由轉變為、才= 1100 C燒、、’。不谷易麟適當的陶竟強度，所以易於長升溫過程剝落或裂 可添加燒結促進劑與漿體黏結 為了改善氮化石夕塗層燒結體的陶瓷強度， 劑來提高其塗層強度，以利長晶製程。 【發明内容】 本發明之目的’在於提供-種長晶用職之鐘塗層塗佈方法可均 勻塗佈該襞體於該掛鋼之内壁， 料與該坩鍋進行長晶時產生介 € 進而^昇長晶材料的成品率，以 :，並提升保護塗層強度，以避免進行長晶材 面反應，且改善該長晶鑄造後的咬模現象， 以降低進行長晶的成本。 201002417 為達到上述之目的，本發明係為一種長晶用掛鋼之保護塗層塗佈方 法，先取一氮化矽粉末及一助燒劑，並加入水、一黏結劑及一消泡劑進行 攪拌為一漿體。當該漿體具適當流動性後，預熱該坩鋼，接著塗佈該漿體 至該坩鍋，以形成一保護塗層於該坩鍋，最後以高溫燒結該保護塗層。 【實施方式】 茲為使貴審查委員對本發明之結構特徵及所達成之功效有更進一步 之瞭解與認識’謹佐雖佳之實關魏合詳細之，說明如後： 請參閱第-圖’係本發明之-較佳實施例之雜示賴。如圖所示， 本實施例係提供-種長晶用_之保職層塗佈方法，於—賴之内壁形 成-保護塗層，而該義之材質選自石英、氧化|s、氧储、石墨及其他 _材料巾擇其-者。本實施例之方法可均勻塗佈該保護塗層於該聰之 内壁’而該保護塗層可減少於進行長晶時，該職内之長晶㈣與該掛鋼 產生介面反應，其中該長晶材料選自Si!i⑽、SiGe、祕及其他長晶材料 中擇其-者，且改善其鑄造後的咬翻^，進啸昇長晶材狀成品 以降低其製造成本。 本實施例所提供之方法係先執行步驟S10，取一氮化石夕粉末及一助燒 劑’並加入水、-黏結劑及一消泡劑進行娜為一浆體，其中步驟则更 =:先混合水、該黏結瓶朗泡劑形成—溶液，接著加人該氮化石夕粉 =於該溶射’最後加人該魏啦已加人化雜末之該溶液中進行 勝形成-賴。其巾聽切粉末與由水、_結航觸鋪所混合 之溶液之用量比為i u，該助燒劑之材料選自Be0、MgG、_、㈣、_、 =、祕、祕，3、副3及其他氧化物帽其—者，其用量必須介於 ^與6wt/0之間，該黏結劑之材料選自pVA、石夕膠液及石夕酸乙醋中擇其一 者’其麟賴由快至慢’崎統切峨。 八 ’利用一特殊預熱爐預熱該 5〇度之間，以尾進行塗佈， ‘該漿體具適當流動性後，先執行步驟S14 坩鍋，使該坩鍋之溫度維持於攝氏30度與攝氏 8 201002417 …通執行步驟S16 ’塗佈該聚體至該掛銷，並控制塗佈該漿體之厚度大於 150μιη，持續至塗佈完成，以形成一保護塗層於該坩鍋之内壁。最後執行步 驟S18 ’以尚溫燒結該保護塗層，其燒結溫度為攝氏1〇〇〇度至攝 之間。 反 π凊—併參閱第二®，為了避免漿射的統梦粉末發生結團或沉搬， 得控制該氮切粉末與由水、該储航__所混合之驗之用量比 為1 : 4 ’於步驟10，先添加部分氮化矽粉末至由水、該黏結劑及該消泡劑 所混合之溶液中，以形成絲體，然而當絲賴拌—段時間後，再執行 步驟S12，再添加釘的氮化石夕粉末至該漿體中，使該氮化石夕粉末均勾分佈 於該㈣中。然後再依序進行步驟S14、S16、S18。其中步驟所添加之 氮化矽粉末及步驟S12所添加之氮化轉末之總用量與由水、該黏結劑及 該消泡劑所混合之溶液之用量比必須維持1 : 4。 而本實施例顧-喷搶倾郷該為了雜絲護塗層之 品^在喷塗前，調整該喷搶之勤大小、σ#Α小及與該賴之距離， 使每次該倾所賴之喷束雜為麵形，該姻狀長度為4()公分，其 寬度為3公分與10公分之間’並控制該喷槍每次噴塗面積、喷塗速度及與 該掛鋼距離等等。然而整個喷塗過程必須控制該掛鋼的溫度維持在攝氏加 度與攝氏50度之間，因此利用紅外線測溫搶量測該坩鍋溫度，以控制塗佈 於該坩鍋之該保護塗層的厚度及其均勻性。 而本實施例之方法主要使用氮化石夕粉末製成該保護塗層，該氮化石夕粉 末具有好賴械性質、<絲(Thennal shQd〇、斷舰度與高_定性， 因此常用於陶究零組件。但由於該氮化石夕粉末熔點高，不容易燒結，一般 若以大氣燒結法’則於燒結後會訂—些的孔洞(VQids)，所職保護塗層 之組織孔隙度較高。 θ 當該氮化矽粉末被使用在長晶用坩鍋之保護塗層時，一般是以漿體塗 層方式披覆’錢覆於姆敵絲護塗層之厚度為⑽⑽與删卿之間， 且因該保護塗層披覆於該坩鍋之内壁，其燒結溫度僅介於攝氏麵度與攝氏 201002417 noo度’該保護塗層燒結後的緻密度不似卫制竟以熱壓成型的燒結 往往留下更多微小孔洞，當經過高溫及長時_小時與叫時之^ 晶過程，會使得高溫炫_金屬液，藉由毛細原理透過塗佈於該掛鋼 保護塗層的空孔’滲穿人該保護塗層，因此，降低此該保護塗層的功能了 使得長晶後鑄件表面發生咬姻題，嚴重時，甚至會使得職材料與長曰曰 材料黏結在-起’·於該獅的去除與降低得料率，或因化學溶钱: 發材純度與其光電轉換效率，因此本實施_由添加雜結趣該跡 劑’以改善上述問題。 疋 另為了獲得緻密的該保護塗層，因此本實施例以濕式混合方式添加該 黏結劑(如PVA、石夕膠液或雜乙酿等)至該槳體，提高該保護塗層未燒结時 之結合強度’以利後續燒結。而本實施例另—特徵為於該氮切粉末;添 加氧化物的助燒劑’再藉由高溫燒結處理，以獲得緻密之該保護塗層進 而降低該紐塗層與長晶材料之反應，齡髓塗層的繼與咬模現象二 -般氮化雜構可以分為高溫穩定师她低溫穩定侧α相，若該 氮化物結構含有較高的α相，則燒結體的微結構為等軸狀晶粒，若該氮化 物結構含有較高的帅，職結體的微結構為長柱狀晶粒，因此，粉末中 所含α與帅比例會影響其燒結密度。本實施例所選用之氮财粉末之α 相比例大於90%，由該氮化石嫌末製成之該保護塗層具有良好的燒結密度。 此外，考直該助燒劑添加量對石夕原料組成的影響，所以對於該助燒劑 的添加量必賴量’且燒結後的魏護塗射__不會與高溫炫_ 起化學反應。目此該助燒結狀磐必須轉於冑溫自由能时安定之陶 竟耐火材料’由Elligam Diagram的自由能變化可知，該助燒劑之材料可選 擇BeO、MgO、CaO、SrO、BaO、Ti〇2、Zr〇2、_2、γ2〇3、則3及其他不會與 石夕產生化學反應之氧化物中擇其-者，本實施例所選擇之助燒劑材料為 AhO3、Mg〇或Υ2〇3，該助燒劑之添加量須介於iw伐與加伐之間，並配合少量 的石夕膠液或PVA等其健結劑’提高雜護塗層燒結強度與魏結後的緻密 201002417 度0 此外，就該保護塗層的燒結溫度選擇，一般氮化矽陶瓷若以熱壓燒結 方式’其燒結溫度須達攝氏1650度與攝氏1800度之間，並維持高溫四小時。 但對本實關之方法^言，因添加簡織助細可提高低溫燒結強度， 以避免尚溫燒結咖·練f結構變化所產生敝縮應力’因賴受熱會發 生相變化’轉變成trydimite and cristQbalite，同時伴隨著體積收縮， 所以該保護塗層之燒結溫度須控制在1200T以内。 述了知本發明所^供之掛銷之保護塗層塗佈方法，本發明之方法 可均勻塗佈該保護塗層於該賴之内壁，以避免長晶時之長晶材料與該掛 鋼產生介面反應，並改善長晶時所產生的咬觀象，進而提昇長 成品率，以降低進行長晶之成本。 ’ 綜上所述，本發明係實為一具有新穎性、進步性及可供產 符合我國專利法所規定之專利帽要件無疑，爰依法提出發 主‘，、 祈鈞局早日賜准專利，至感為禱。 °月， 惟以上所述者，本發明之—較佳實施_已，並非 明實施之細，舉驗本個_請專利細料之_、财 神所為之鱗變化與修均應包括於本發明之申請專利範圍内。’ 月 【圖式簡單說明】 第一圖：本發明之一較佳實施例之流程示意圖；以及 第二圖：本發明之另一較佳實施例之流程示意圖。 【主要元件符號說明】 無 11There are ways to effectively reduce the multi-turning of long-grain stains (4), such as improving the nitridation properties to reduce the decomposition of the crystallization process of the crystal growth process (DeeQ_sitiQn), bribery, lion surface area, no product ratio (such as steel enlargement) from the previous patent literature The sintering temperature of tantalum nitride as described in U.S. Patent No. 6,164,425 and U.S. Patent No. 1971 is only 5 〇〇 1 〇 9 When the powder is sintered at normal pressure, it must be heated to a dirty state before it is converted into = 1100 C burned, '. Not Gu Yilin's proper pottery strength, so it is easy to lengthen the process of peeling or cracking. Adding sintering accelerator and slurry bonding. In order to improve the ceramic strength of the sintered body of the nitride coating, the agent can improve the coating strength to facilitate the growth of the crystal. Process. SUMMARY OF THE INVENTION The object of the present invention is to provide a method for coating a coating of a crystal of a long crystal, which can uniformly coat the inner wall of the steel body, and when the material is crystallized with the crucible. Further, the yield of the crystal growth material is increased to: and the strength of the protective coating layer is increased to avoid the reaction of the long crystal surface, and the biting phenomenon after the casting of the crystal growth is improved to reduce the cost of performing the growth of the crystal. 201002417 In order to achieve the above object, the present invention is a protective coating coating method for long crystal steel, which first takes a tantalum nitride powder and a sintering aid, and adds water, a binder and an antifoaming agent for stirring. For a slurry. After the slurry has proper fluidity, the niobium steel is preheated, and then the slurry is applied to the crucible to form a protective coating layer in the crucible, and finally the protective coating is sintered at a high temperature. [Embodiment] In order to make your reviewer have a better understanding and understanding of the structural features and the effects achieved by the reviewer, please refer to the following: A preferred embodiment of the invention - a preferred embodiment. As shown in the figure, the present embodiment provides a protective layer coating method for growing a crystal, and forming a protective coating on the inner wall of the substrate, and the material of the material is selected from the group consisting of quartz, oxidation|s, oxygen storage, Graphite and other materials to choose from. The method of the embodiment can uniformly coat the protective coating on the inner wall of the Cong and the protective coating can be reduced when the crystal growth is performed, and the crystal growth (4) in the occupation generates an interface reaction with the steel, wherein the length The crystal material is selected from the group consisting of Si!i (10), SiGe, and other crystal growth materials, and improves the bite turn after casting, and rises into a long crystal form to reduce the manufacturing cost. The method provided in this embodiment firstly performs step S10, taking a nitriding powder and a sintering aid and adding water, a binder and an antifoaming agent to perform a slurry, wherein the step is more: first The mixed water, the viscous bottle is formed into a solution, and then added to the nitriding powder = in the solution of the sol- ing, and the addition of the weila has been added to the solution. The ratio of the amount of the towel to the cut powder and the solution mixed by the water and the hangover is iu, and the material of the sintering aid is selected from Be0, MgG, _, (4), _, =, secret, secret, 3. For the third and other oxide caps, the amount must be between ^ and 6wt/0, and the material of the binder is selected from the group consisting of pVA, Shishi gum and Ethyl acetate. Lin Lai is going from slow to slow.八' Use a special preheating furnace to preheat the 5 degrees between the two, and apply the tail with the tail. 'After the slurry has proper fluidity, first perform the step S14 crucible to maintain the temperature of the crucible at 30 °C. Degree and Celsius 8 201002417 ... pass the step S16 'coating the polymer to the hanging pin, and control the thickness of the coated slurry to be greater than 150 μm until the coating is completed to form a protective coating on the crucible Inner wall. Finally, step S18' is performed to sinter the protective coating at a temperature of between 1 and 10 degrees Celsius. Anti-π凊—and refer to the second®. In order to avoid the agglomeration or sinking of the plasma powder, the ratio of the nitrogen cut powder to the water and the storage __ is controlled to be 1: 4 'In step 10, a portion of the tantalum nitride powder is first added to the solution mixed with water, the binder and the antifoaming agent to form a filament, but after the silk is mixed for a period of time, step S12 is performed. And adding a nailed nitriding powder to the slurry, so that the nitriding powder is uniformly distributed in the (4). Then, steps S14, S16, and S18 are sequentially performed. The ratio of the total amount of the tantalum nitride powder added in the step and the nitriding powder added in the step S12 to the amount of the solution mixed with water, the binder and the antifoaming agent must be maintained at 1:4. In the present embodiment, the product of the shredded protective coating is adjusted for the size of the smashing, the size of the smashing, and the distance from the smashing, so that each time Lai's spray is miscellaneous, the length of the marriage is 4 () cm, the width is between 3 cm and 10 cm' and controls the spray area of each spray gun, the spraying speed and the distance from the steel. Wait. However, the entire spraying process must control the temperature of the hanging steel to be maintained between Celsius and 50 degrees Celsius, so the temperature of the crucible is measured by infrared temperature measurement to control the protective coating applied to the crucible. Thickness and uniformity. The method of the present embodiment mainly uses the nitriding powder to form the protective coating, and the nitriding powder has good mechanical properties, < silk (Thennal shQd〇, ship breaking degree and high_qualification, so it is often used in ceramics) Investigate the components. However, because the melting point of the nitriding powder is high, it is not easy to sinter. Generally, if the atmosphere is sintered, the pores (VQids) will be ordered after sintering, and the porosity of the protective coating is higher. θ When the tantalum nitride powder is used in the protective coating of the long crystal crucible, it is generally coated with a slurry coating. The thickness of the coating is (10) (10) and deleted. Between, and because the protective coating is applied to the inner wall of the crucible, the sintering temperature is only between Celsius and Celsius 201002417 noo degrees. The density of the protective coating after sintering is not like the thermoforming. Sintering tends to leave more tiny holes. When the high temperature and long time _ hours and the time of the crystallization process, the high temperature _ metal liquid, through the capillary principle through the coating of the steel protective coating The hole 'penetrates the person's protective coating, therefore, lowering this protection The function of the protective coating makes the surface of the casting after the crystal growth occur. In serious cases, even the material and the long enamel material are bonded together - the removal and reduction rate of the lion, or chemical dissolution Money: the purity of the hair material and its photoelectric conversion efficiency, so this embodiment _ by adding the miscellaneous traces to improve the above problem. 疋 In order to obtain the dense protective coating, the present embodiment adds the wet mixing method. A bonding agent (such as PVA, Shixi gum or hybrid) to the paddle body improves the bonding strength of the protective coating when it is not sintered to facilitate subsequent sintering. This embodiment is further characterized by the nitrogen The powder is cut; the oxide-added sintering agent' is further processed by high-temperature sintering to obtain a dense protective coating, thereby reducing the reaction between the coating and the growth of the crystal growth material, and the subsequent embedding phenomenon - The nitridation heterostructure can be divided into a low temperature stable side α phase, and if the nitride structure contains a high α phase, the microstructure of the sintered body is equiaxed grains, if the nitride structure contains The higher the handsome, the microstructure of the job is Columnar grains, therefore, the ratio of α and handsome contained in the powder affects the sintered density. The α ratio of the nitrogen powder used in this embodiment is greater than 90%, and the protective coating made of the nitride is suspected. The layer has a good sintered density. In addition, the influence of the amount of the sintering aid on the composition of the material of Shixi is determined, so the amount of the additive to be added must be 'and the amount of the stencil after sintering __ will not The chemical reaction with the high temperature ray _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ , CaO, SrO, BaO, Ti〇2, Zr〇2, _2, γ2〇3, then 3, and other oxides that do not chemically react with Shixi, the combustion aid selected in this embodiment The material of the agent is AhO3, Mg〇 or Υ2〇3, and the amount of the sintering aid must be between iw cutting and cutting, and combined with a small amount of stone cement or PVA and other cementing agent to improve the coating The sintering strength of the layer and the density after the Weijun 201002417 degree 0 In addition, the sintering temperature of the protective coating is selected. In terms of general hot press sintering silicon nitride ceramic by 'to be up to the sintering temperature between 1650 degrees Celsius and 1800 degrees Celsius and maintaining the high temperature for four hours. However, for the method of this practical method, the addition of simple weaving can improve the low-temperature sintering strength, so as to avoid the shrinkage stress caused by the structural change of the temperature-sintering coffee, and the change of the phase change due to heat will be converted into trydimite and cristQbalite, accompanied by volume shrinkage, so the sintering temperature of the protective coating must be controlled within 1200T. The method for coating a protective coating provided by the present invention is described. The method of the present invention can evenly coat the protective coating on the inner wall of the lining to avoid the growth of the crystal growth material during the growth of the crystal. Produces an interface reaction and improves the bite phenomenon generated during the growth of the crystal, thereby increasing the long yield and reducing the cost of performing the growth. In summary, the present invention is a novel, progressive and available product that meets the requirements of the patent caps stipulated in the Patent Law of China, and the applicants are legally proposed, and the Prayer Council grants patents as soon as possible. Pray for the feeling. °月, except for the above, the present invention - the preferred embodiment _ has been, not the details of the implementation, the test _ the patent fines, the sacred changes and repairs should be included in the present invention Within the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing a preferred embodiment of the present invention; and a second drawing showing a flow chart of another preferred embodiment of the present invention. [Main component symbol description] None 11