電鍍原理

1、電鍍原理簡介The brief introduce of plating theory,,一. 基礎(chǔ)理論 the basis of plating,1.電鍍原理 The principle of plating:,Cathode reactions,Cathode reactions,金屬離子氧化成離子，陽極將電子釋放到外電路。Oxidation of metal to ions , the anode release of

2、electrons to external circuit,Cathode reactions,離子被還原，陰極從外電路得到電子。 Reduction of ions, the cathode draw electrons from the external circuit。,簡單金屬離子或絡離子通過電化學方法在固體表面上放電還原為金屬原子附著于電極表面從而獲得一層金屬的過程。 Plating is a process that s

3、ingle metallic ions or complex-ions was reduced to be metallic atom coating upon the surface of pole through electrochemistry.,電鍍時爲了得到具有某種特性的金屬層，如：硬度，光亮度，耐腐蝕及在電鑄方面複製同樣的形狀To obtain a metallic coating having certain prope

4、rties such as hardness, brightness, corrosion resistance and to reproduce identical forms in electroforming,2.電鍍的目的 The purpose of plating:,電鍍過程示意圖 The schematic diagram of plating process,3.主要定律----法拉第定律The major law-

5、---faraday’s law,1安培的電流1秒鐘的時間通過的電量等於1庫倫。法拉第定律：1個法拉第即96500庫倫的電量可以沉積1克當量的金屬?？水斄渴墙饘俅蟮脑恿砍端幕蟽r。One ampere flowing for one second represents one coulomb. Faraday’ law states that 96500 coulombs (one faraday) will deposit o

6、ne gram equivalent weight of a metal . Equivalent weight is the atomic weight of the metal divided by it’s valence.,鍍層重量Weight of metal deposited grams=,At.Wt.（原子量）,96500 coulombs deposit,Thickness （m

7、ils）=A/Ft2×hours,一. 基礎(chǔ)理論 the basis of plating,,Valence (化合價),,二. 脫脂工站 degrease,1.清洗劑的工作原理The working principle of detergent,(1).分散Dispersion 分散就是靠表面活化劑或清洗劑的一些組分將固體顆粒分解掉的方法。它能有效的處理掉拋光后留下的殘餘物。Dispersion is a method

8、 whereby solid particles are broken down to small particles by the action of surfactants and other components in a cleaner . It is effective for residue left from polishing operations (2).皂化 saponification皂化是將脂肪酸或脂肪油或

9、其它可反應得到污染物轉(zhuǎn)化成水溶性的混合物。提高溫度，濃度和pH值都會促進反應的速度和反應的完成。Saponification is the chemical action by which fatty acid , fatty oil or other reaction soil is converted to a water soluble compound (soap) . Elevated properly temperatur

10、es , concentration , and pH promotes the speed and completion of the reaction.(3).乳化Emulsification乳化也是一種化學過程，他是通過表面活性劑將油污分解成細小的可溶性小液滴從而分散并懸浮在溶液當中。Emulsification is a chemical process by which surfactants penetrate oi

11、ls and break them down to tiny water soluble globules dispersed and suspended in solution.,二. 脫脂工站 degrease,2.清洗的目的Purpose for cleaning:,（1）.保障鍍層的結(jié)合力。To provide adhesion on the subsequent deposits. （2）.得到高品質(zhì)的完美鍍層。To

12、obtain a high quality finish deposit.（3）.使鍍層具有期望的各種特性。To obtain the desired properties of the deposits.,3.清洗的種類The type of cleaning,（1）.機械清洗Mechanical cleaning. （2）溶劑清洗：脫脂，乳化，固液相分離。Solvent cleaning : degreasing ,emul

13、sion ,diphase. .鹼洗：浸泡，電解，乳化。Alkaline cleaning : soak ,electro ,ultrasonic.,二. 脫脂工站 degrease,4.清洗劑的三種主要成份The three major components in alkaline detergent,主體——氫氧化鈉或氫氧化鉀，硅酸鹽，碳酸鹽，濃縮磷酸鹽。 Builders—sodium hydroxide or pota

14、ssium hydroxide ,silicates ,carbonates ,condensed phosphates 添加劑——螯合物可以消除硬水和金屬離子的影響。Additives—chelating agents to counteract effects of hard water and metal ions.表面活性劑——置換和分解油污。降低金屬表面上清洗劑的表面張力，使得清洗劑可以完全覆蓋在金屬表面。 Surfac

15、tants—displace and disperse soil . Lower surface tension of cleaner at metal surface for uniform coverage .,5.電解清洗反應Electro-cleaning reaction,陽極反應Anode reaction : 4(OH)- - 4e → 2H2O+O2↑陰極反應Cathode reaction : 4H2O+4e →

16、 4(OH)-+H2 ↑,陰極釋放出氫氣，氫氣量是陽極釋放氧氣量的兩倍。某些氧化膜被還原。但有個缺點金屬離子會以疏松的贓物形式沉積在工件表面。Hydrogen liberated at the cathode. The volume of the hydrogen is twice that of oxygen generated at the anode. Certain oxide films are reduced. A dis

17、advantage is that metallic ions can deposit on the work as a loose adherent smut.,三. 酸活化工站 acid activating,2.酸洗的種類The type of acid activating:浸泡，電解soak, electro.,去除金屬表面的氧化膜，使下面的金屬層與基材有好的結(jié)合力，并中和殘留在表面的鹼性氧化膜To Remove oxid

18、es from the surface of the metal to obtain good bonding of the subsequent deposit. Neutralize any residual alkaline film left on the surface.,3.酸浸的化學反應Chemistry of pickling,Sulfuric Acid + caustic →water+ sodium sulfate,

19、Sulfuric Acid + steel → hydrogen + ferrous sulfate,Sulfuric Acid + copper oxide → water + copper sulfate,1.酸活化的作用The function of acid activating,四. 鍍鎳工站 nickel plating,結(jié)晶細緻Grain refinement.溶液導電良好Solution conductivity w

20、ell.減少陽極極化Reduces anode polarization. 提高分散能力Improves throwing power.,鍍鎳前一般先鍍一層預鎳 We 預鎳的作用Function for pre-plating nickel:用於加強結(jié)合力的起始鎳層Initial nickel layer for adhesion. 對重複電鍍的結(jié)合力有幫助Good for re-plates adhesion.防止半

21、光亮鎳中鐵雜質(zhì)的積累Prevents build up of iron in semi bright nickels.在各種電流密度下均有良好的結(jié)合力Good coverage at various current.,簡介 The brief introduce,1.預鎳 Pre-plating nickel:,2.氨基磺酸鎳的優(yōu)點 advantage of Nickel sulphamate:,1.氨基磺酸鎳(Ni(SO3NH

22、2)2.4H2O) Nickel sulphamate: 2.氯化鎳Nickel chloride: 3.硼酸Boric acid:4 .氨基磺酸(NH3SO3) aminosulfonic acid: 5 .MP-288Organic semi-brightener:,3.鍍鎳標準哈氏片 :,4.鍍液組份 : the bath components,1.氨基磺酸鎳(Ni(SO3NH2)2.4H2O) Nickel s

23、ulphamate:,作用：為鍍液提供Ni2+，具有降低鍍層內(nèi)應力覆蓋率佳，鍍層光澤性好的特點。Function: Supply Ni2+ for solutions, dropping stress, superior fraction of coverage and glossiness of deposits.,氯化物幫助陽極溶解，并與光亮劑配合以增加光亮度和填平效果。The chloride helps anodes di

24、ssolve and works with brightener for full brightness and leveling.增加導電性和限制電流密度。 Increase conductivity and limiting current density.高氯化物會提高鍍層硬度並且會導致延展性變差及帶來高的內(nèi)應力。High chlorides produces harder deposits, and can lead

25、to reduced ductility and high internal stress.,3.硼酸Boric acid:,在陰極表面作為緩沖劑并補充氫離子，維持酸堿度在某一個點以防鎳鹽沉淀。 Functions as a buffer and replenish hydrogen ions at the cathode film, maintain the pH below the point at which nickel wi

26、ll precipitate.減少針孔。 Reducing pores.,2.氯化鎳Nickel chloride:,四. 鍍鎳工站 nickel plating,4 .氨基磺酸(NH3SO3) aminosulfonic acid:用來降低鍍液的PH. reduce pH value of solution,5 .MP-288有機半光亮劑Organic semi-brightener: 含軟化劑及潤濕劑,降低了鍍液表面張力,增強

27、了鍍液對鍍件表面的潤濕作用,清除氫氣,避免針孔的產(chǎn)生.,Organic semi-brightener contain softening agent and wetting agent, can reduce interracial tension, enhance the solution wetting ability on surface of pole. degassing of hydrogen. Avoid occurr

28、ing pores.,影響因素 Affection factor:,四. 鍍鎳工站nickel plating,7.溫度Temperature:,總體範圍在50~71度。General range 50~71oC低溫會產(chǎn)生較硬的，延展性較差的沉積層，陰極效率較低。高溫情況下反之，且高溫可以提高溶液的導電性。Lower temps produce harder less ductile deposits with slightly l

29、ower cathode efficiency. Converse is true with higher temps, and higher temps improve solution conductivity.,9.陰極電流密度cathode current density:,對于避免陽極極化（將使陽極無法溶解）非常重要。電鍍時陽極面積會減小，一次定期添加金屬陽極保持陽極面積是非常重要的。 Important to avoid

30、anode polarization (inability of the anode to corrode). Anode area diminishes during plating therefore it is important to maintain the anode area with regular adds of metal.,8.陽極電流密度Anode current density:,決定鎳的沉積速度，陰極電流密度

31、和時間直接關(guān)系到鍍層的厚度。低的電流密度0. 5A/dm2 或更小，能鍍出金屬雜質(zhì)，如銅，鋅。Determines the plating rate of nickel and is directly related to the thickness obtained along with time. 5A/dm2 or less can plate out metallic impurities like copper and zi

32、nc.,6.pH 值pH factors:,總體範圍在3~5之間 General range of 3~5.低酸堿度可提高延展性，減少硬度和降低陰極效率Lower pH values tend to improve ductility, reduce hardness and reduce cathode efficiency. 高的酸堿度可減少延展性，使鍍層變硬，稍微提高陰極效率。Higher pH values (to6)

33、tend to reduce ductility produce harder deposits and slightly improves cathode efficiency.,五. 鍍錫工站 Tin plating,,1.烷基磺酸錫: 提供鍍液中的錫離子.總體範圍控制在35-55g/L。Stannous methane sulfonate: it is the source of stannous ions in methan

34、e sulfonate electrolytes.General concentrate range is controlled 35-55g/L,2.烷基磺酸: 為鍍液提供必要的導電能力,能夠保證陽極的正常溶解Methane sulfonic acid : it provides the necessary conductivity to the methane sulfonate electrolytes, and is res

35、ponsible for proper anode corrosion.,3.濕潤劑：在高速電鍍的體系中這種添加劑可以在低泡沫環(huán)境下得到優(yōu)良鍍層。它可以在很寬的電流密度範圍下得到結(jié)構(gòu)緊密，外觀均一，有光澤的，無錫鬚的鍍層。P: this additive is a low-foam carrier/grain refiner designed for use in high-speed plating equipment. This

36、 additive provides consistent, uniform, satin, whisker-free tin deposits over a very wide current density range.,,2 .酸濃縮液:濃度為70%的強酸,無色液體.濃度控制範圍為100-200ml/L,具有增強陽極溶解效率,增強鍍液導電性能,以及平整鍍膜的作用。,3 .濕潤劑WA401:降低界面張力,防止表面針孔.與WA14成分

37、相同,可通用,其濃度控制範圍為70-120ml/L,4 .光亮劑HD:增加表面光亮度.與BR14相同相同,可通用,其濃度控制範圍為2-10ml/L,5 .拓展劑RX1:一級光亮劑載體,有增加光亮範圍的作用.與RX14成分相同,可通用,其濃度控制範圍為2-10ml/L.,6 .穩(wěn)定劑SB:抗氧化劑,有效防止預防二價錫氧化為四價錫,延長鍍液的使用時間,其濃度控制範圍為2-10ml/L.,五. 鍍錫工站 Tin plating,六. 鍍鈀/鈀

38、鎳工站Pd/Ni plating,1 .氯化氨鈀(Pd(NH3)4Cl2):主鹽. 用于提供電鍍所需的鈀,一般濃度控制在29.4~49g/l之間Palladium metal: it is the source of Pd ions in electrolytes, general concentration range 29.4~49g/L,4 .氨水((NH)3.H2O):用于增加PH值,控制到7.8~8.5Ammonium h

39、ydroxide: pH can be increased by addition of 50% ammonium hydroxide, general range 7.8~8.5.,2 . 鎳補充劑:主鹽,供給電鍍所需的鎳, 一般濃度控制在9~15g/l之間.Nickel metal: it is the source of Pd ions in electrolytes, general concentration range 9

40、~15g/L,6 .鈀鎳添加劑:白色溶液,依HULL CELL TEST或依分析結(jié)果添補,其含量可用UV/VIS分析.Pallnic additive : addition of Pallnic additive solution should normally only be made on the recommendation of HULL CELL TEST or on the basis of UV/VIS analysis

41、.,5 .鈀鎳光亮劑NO.1基本光澤劑, 一般含量超出所需量,消耗量依HULL CELL TEST或分析結(jié)果添補.Brighter NO1 is the basic brightener and its concentration is normally in excess of that required. Replenishment should be made only on the basis of analysis or o

42、n the HULL CELL TEST.,3 .導電鹽:用于增加鍍液導電能力,對溶液波美值有貢獻.波美度控制為8~16.每20g的Conducting Salt可提升1 Be。.Conducting salt: This should only be used to increase electrolyte specific gravity in high drag-out situation, which should be co

43、ntrolled between 8~16 oBe, 20g/L of conducting salt increases the specific gravity by 1 oBe,鈀鎳標準哈氏片 :,七. 鍍金工站 gold plating,1 .氰化金鉀(KAu(CN)2)：主鹽.為鍍液補充金離子.一般濃度控制在11~15g/l之間.potassium gold cyanide: it is the source of Au

44、ions in electrolytes, general concentration range 8~12g/L,2 .鈷光澤劑：鈷光澤劑,為鍍液補充鈷離子,可增加鍍層的硬度及耐磨性,改善鍍層光澤,亦有調(diào)整鍍膜分布的功能.Cobalt Brightener: it is the source of Co ions in electrolytesCobalt is co-deposited with gold to increase

45、 the hardness and wear properties, improving the distribution of deposits thickness.,3 .補充光澤劑/補充添加劑: 光澤劑可以使得鍍層在金含量較低的環(huán)境下有較寬的光亮區(qū)域，并可以維持槽液添加劑濃度用,保持沉積速率,產(chǎn)品表面特性. 光亮劑應當隨著金和鈷的補加而補加。Replenish brightener/additive: maintain addi

46、tive concentration and speed of deposit, good wear property. This is an organic brightener designed to extend the bright range of the process at low gold concentrations. Replenishment of the additive should be carried o

47、ut with replenishment of the gold and cobalt.,4 .檸檬酸:用來降低鍍液的PH值;一般隨著電鍍的進行,鍍液的PH值會上升,儅PH值大于5時,過渡金屬與氰化物形成穩(wěn)定的絡合物,而不易與金共沉積, 一般PH值控制在4.4-4.7.Citric acid：it can reduce the pH value, which will increase when electrolysis. Tran

48、sition metal will reacts with any “free cyanide” then this will form the very strong complex which will not take part in co-deposited with gold when the pH value above 5. General range 4.4~4.7.,5 .平衡鹽 :其主要成份為草酸鹽,具有還原性,用于

49、抑制鍍液中Au+氧化成Au3+(無效金),是導電鹽中的一種成分.在電鍍過程易于氧化消耗.若含量低,會提高鍍層中的鈷含量及內(nèi)應力.Balance salt: Its major component is oxalate possessing reducibility, so it can prevent Au+ from being oxidized ineffective Au3+. The material is the par

50、t of the conducting salt that is oxidised during electrolysis and additions should be made based on analysis by precipitation. If the content of this material cut down for excess depleted, so the cobalt content of deposi

51、t will increase and internal stress will increase.,七. 鍍金工站 gold plating,6 .導電鹽:用于增加鍍液導電能力,對溶液波美值有貢獻.波美度控制為10~25.每16g的導電鹽可提升1Beo.Conducting salt: This should only be used to increase electrolyte specific gravity in high

52、drag-out situation, which should be controlled between 10~25 oBe, 16g/L of conducting salt increases the specific gravity by 1 Beo,八. 後處理工站post-plating,1 .NF1201:在鍍層表層形成硫化保護膜,抵抗腐蝕.濃度控制範圍為1-3ml/LIt will product resist v