安美特 电镀基础知识培训

REQUIREMENTS 要求


SOURCE OF DIRECT CURRENT 直流电源 A PLATING TANK 电镀槽 A SOLUTION CONTAINING THE DISSOLVED SALTS OF THE METAL TO BE PLATED 含有待镀的可溶性金属盐的溶液 ANODE ( POSITIVE ELECTRODE ) 阳极（正电极） A PREPARED OBJECT CATHODE ( NEGATIVE ELECTRODE ) 准备好的待镀工件--阴极（负电极）
Ni++ + 2eO2 + 2H2O + 4eO2 + 4H+ + 4e-
RATE OF CURRENT FLOW 电流速率
Ohm’s Law 欧姆定律
Amperes安培 = Volts 伏特 Ohms 欧姆 I 电流= E 电压 R 电阻
FARADAY’S LAW 法拉第定律 Factors 要素
58.7
2
x grams
CALCULATING THICKNESS FROM WEIGHT 从重量计算厚度
Thickness = WT
density x area
1um=10 -4 cm 1mil = 25. 4 um
EXAMPLE :
wt = 0.136 grams
. Density of Ni = 8.9
POLARIZATION 极化
E = IR E = Volts伏特 ( potential difference电位差 ) R = Resistance电阻 ( resistance of solution to the flow of current 溶液对电流的阻抗) I = Current电流 ( flow of electricity电荷的移动 ) E = CURRENT电流 (I) X RESISTANCE电阻 (R) Ep = Change in potential difference due to Polarization from resistance. 由于电阻升高造 成的极化,极化导致的电位差的改变.
WEIGHT OF NICKEL PLATED 电镀镍的重量
KNOWN FACTORS已知的条件
Current 电流= 50 amps安培 Time 时间 = 15 mins分钟 原子量 At. Wt. Ni = 58.7 Valence = 化合价, 2 价
CALCULATION 计算
96,500 = 45,000 X = 13.7 GRAMS 克
Thicknபைடு நூலகம்ss = 0.136
8.9 x 4
Area = 4 cm2
Answer = 1.5 mils
CURRENT IN CELL 电镀槽中的电流
Anode阳极-e = cathode阴极 +e
Anode阳极-e = corrosion溶解 -e + Oxygen氧 -e
Cathode阴极+e = plating所镀金属+e + hydrogen氢+e


NICKEL 镍 Copper 铜
DECORATIVE CHROMIUM 装饰铬 TESTING 测试 FILTRATION 过滤 TROUBLE SHOOTING 故障处理
WHAT IS ELECTROPLATING ? 什么是电镀？

THE DEPOSITION OF A METALLIC COATING UPON A NEGATIVELY CHARGED CATHODE BY THE PASSING OF AN ELECTRIC CURRENT 在电流通过时，有金属层沉积在带负电荷 的阴极表面.
The exchange of electrons at the anode and the cathode or the total flow of current at each electrode is always equal. 电子在阳极和阴极上交换,在阴阳极上流动的电 流总是相等的。
DEPOSITION WITH H 2 LIBERATION 伴随着氢气释放的沉积
Basic ELECTROCHEMISTRY 基本的电化学理论
ELECTROCHEMISTRY 电化学 Plating Cell 电镀槽
Rectifier整流器
+
Ni++
_ Ni++
+
Cl-
ClCATHODE阴极 ANODE阳极
ANODE阳极
CATHODE REACTIONS 阴极反应
Cathode 阴极
WHAT IS DIRECT CURRENT ? 何为直流电？

THE FLOW OF ELECTRONS IN THE SAME DIRECTION BETWEEN POSITIVE AND NEGATIVE ELECTRODES 在正负电极之间电子向同样的方向移动.
WHAT IS A PLATING SOLUTION ? 电镀液是什么？

A CONDUCTING MEDIUM FOR THE MOVEMENT OF METAL IONS IN SOLUTION BETWEEN AN ANODE AND A CATHODE 溶液中在阳极与阴极间金属离子移动的导电 介质.
WHAT IS pH ? 什么是pH值？
THE MEASUREMENT OF ACIDITY OR ALKALINITY 用来度量酸碱度的 ON A SCALE FROM 0 TO 14 pH值的范围处于0-14之间 0 TO 6.9 BEING ACIDIC AND 7.1 TO 14 ALKALINE AND 7.0 BEING NEUTRAL. 小于7的为酸性，大于7且小于等于14的为碱性， 7.0为中性
Amperes 安培
Time 时间
Equivalent Weight of Metal 金属当量
FARADAY’S LAW 法拉第定律
One ampere flowing for one second represents one coulomb. Faraday’ law states that 96,500 coulombs (one Faraday) will deposit one gram equivalent weight of a metal. Equivalent weight is the atomic weight of the metal divided by it’s valence.
ANODE REACTIONS 阳极反应
Anode 阳极
Oxidation of metal to ions 金属氧化成阳离 子 Release of electrons to external circuit 将 电子释放至外部电路 TYPICAL REACTION 典型的反应

Ni
4OH2H2O
Atotech (China) Chemicals Ltd.SH 安美特上海青浦分公司
PRESENTS
ELECTROPLATING TRAINING 电镀培训
OUTLINE 内容提要


INTRODUCTION 介绍 ELECTROCHEMISTRY 电化学 CLEANING & PREPLATE 清洗及预镀

HOW ARE PLATING SOLUTION MAINTAINED ? 如何维护电镀液？



CHEMICAL ANALYSIS OF THE CONSTITUENTS 持续的化学分析 HULL CELL PLATING TESTS 赫氏槽电镀测试 ADDITION OF CHEMICALS 添加化学品 ELIMINATION OF CONTAMINANTS 去除污染物 PERIODIC PURIFICATION 定期净化 REGULAR INSPECTION OF PARTS FOR DEFECTS 缺陷/次品的常规检查 PHYSICAL TESTING 物理测试
Reduction of ions离子还原反应 Draw electrons from the external circuit从 外部电路中吸收电子 TYPICAL REACTION 典型的反应

Ni++ + 2e2H+ + 2e4H2O + 4e-
Ni (metal 金属)
H2 2H2 + 4(OH)-
METAL SALTS IN PLATING SOLUTION 电镀液中的金属盐 SOLUBLE METAL ANODES 可溶性的金属阳极

WHAT ARE ANODE BAGS ? 什么是阳极袋？

ANODE BAGS ARE POROUS MEMBRANES PLACED AROUND ANODES TO COLLECT SLUDGE FORMING ON THE DISSOLVING ANODE 阳极袋是包扎在阳极外面,会将电镀过程中产 生的阳极泥收集在袋内的多孔的袋。
% Efficiency效率 = Actual Ni Plated实际镀的镍 X 100 Theoretical (Faraday’s Law ) 理论的（法拉第定律）
FACTORS AFFECTING PLATING CURRENT 影响电镀电流的因素


Hydrogen Liberation ( cathode ) 氢气释放（阴极） Oxygen Liberation ( anode ) 氧气释放（阳极） Polarization 极化 Concentration Polarization ( Diffusion ) 浓度极化（扩散） Hydrogen Overvoltage 氢过电位
1安培的电流1秒的时间通过的电量等于1库仑。
法拉第定律：1个法拉第即96,500库仑的电量可以 沉积1克当量的金属。克当量是金属的原子量除以 它的化合价.
FARADAY’S LAW 法拉第定律
weight of metal deposited 沉积的金属重量
96,500 Coulombs Deposit At. Wt. = grams 96,500库仑的镀层 Valence
WHAT IS THE PURPOSE ? 电镀的目的是什么？

TO OBTAIN A METALLIC COATING HAVING CERTAIN PROPERTIES SUCH AS HARDNESS, BRIGHTNESS, CORROSION RESISTANCE AND TO REPRODUCE IDENTICAL FORMS IN ELECTROFORMING. 是为了得到具有某种特性的金属层，如：硬 度、光亮度、耐腐性及在电铸方面复制同样 的形状.
WHAT IS A METAL ION ? 什么是金属离子？

A METAL ION IS AN ATOM OF A METAL HAVING A POSITIVE ELECTRICAL CHARGE 金属离子是带正电荷的金属原子(失去电子)
WHAT ARE THE SOURCES OF METAL IONS ? 金属离子来自何处？
POLARIZATION 极化
EP= Polarization Ep
E
R= E I I
CONCENTRATION POLARIZATION 浓度极化
CONCENTRATION OF METAL IONS BUILD ON THE SURFACE OF THE ANODE 阳极表面的金属离子浓度 CONCENTRATION OF THE METAL IONS DECREASE AT THE SURFACE OF THE CATHODE 阴极表面的金属离子浓度减少 CHANGE IN ANODE AND CATHODE FILMS CAUSES POLARIZATION 阳极和阴极膜层的改变导致了极化
NET RESULT 最终的结果 Cathode Efficiency Reduced 阴极电流效率的降低 pH Increased pH值升高
1.
2.
H2 2H+ Ni+2 Ni+2
Anode阳极
Cathode阴极
PLATING EFFICIENCY AND TIME OF PLATING 电镀效率和电镀时间