PCB部落格 - PCB板電鍍銅工藝淺析

1 的分類 PCB電路板 electroplating process:
Acid Bright Copper Electroplating Nickel Electroplating / Gold Electroplating Tin

2. Process flow:
Pickling → full plate copper plating → pattern transfer → acid degreasing → secondary countercurrent rinsing → micro-etching → secondary → pickling → tin plating → secondary countercurrent rinsing Countercurrent rinsing → pickling → pattern copper plating → secondary countercurrent rinsing → Nickel plating → secondary washing → immersion in citric acid → gold plating → recycling → 2-3. grade pure water washing → drying

3. Process description:
3.1 Pickling
1) Function and purpose: To remove oxides on the board surface and activate the board surface, 總濃度為5%, 有些保持在10%左右, mainly to prevent the water from being brought into the tank and causing the sulfuric acid content to be unstable;
2) The acid leaching time should not be too long to prevent the surface of the board from oxidizing; after a period of use, the acid solution should be replaced in time when the acid is turbid or the copper content is too high to prevent contamination of the copper electroplating cylinder and the surface of the board;
3) C.P grade sulfuric acid should be used here;

3.2全板鍍銅：也稱為銅, 板電, Panel-plating
1) Function and purpose: To protect the thin chemical copper just deposited, 防止化學銅氧化後被酸腐蝕, 並通過電鍍添加到一定程度.
2) Process parameters related to copper electroplating on the whole board: the main components of the bath are copper sulfate and sulfuric acid, 採用高酸低銅配方，保證電鍍過程中板面厚度分佈均勻，深孔和小孔的深鍍能力； 硫酸含量大多數為180 g/L, 大多數達到240克/L 硫酸銅的含量一般在75克左右/L, 向浴液中加入微量氯離子, 作為輔助光澤劑和銅光澤劑，共同發揮光澤效果； 銅輕劑的加入量或開瓶量一般為3-5ml/L, 而銅光劑的添加一般按千安時的方法或根據實際生產板的效果進行補充； 全板電鍍電流計算一般為2A / 平方分米乘以電路板的可電鍍面積. 對於整個董事會, 它是板長dm×板寬dm×2×2A/DM2； 銅柱的溫度保持在室溫, 一般溫度不超過32度. 它被控制在22度, 所以在夏天因為溫度太高, it is recommended to install a cooling temperature control system for the copper cylinder;
3) Process maintenance:
Replenish the copper light agent in time according to the thousand ampere hours every day, 按100-150ml加入/KAH； 檢查過濾泵工作是否正常，是否漏氣； 每2-3小時, 在陰極導電棒上塗一塊乾淨的濕布. Scrub clean; regularly analyze the copper jar copper sulfate (1 time/week), sulfuric acid (1 time/week), chloride ion (2 times/week) content, 並通過霍爾電池測試調整光劑含量, 及時補充相關原材料； 每週應清潔陽極導電棒和油箱兩端的電力連接器, 鈦籃內陽極銅球應及時補充, 電解應在0的低電流下進行.2-0.5 ASD，持續6-8小時； 每月檢查陽極鈦籃袋是否損壞, 損壞的應及時更換； 檢查陽極鈦籃底部是否有陽極污泥堆積, 如果是這樣, 及時清理； 用炭芯連續過濾6-8小時, 同時用小電流電解去除雜質； 大約每六個月, it is determined whether large-scale treatment (activated carbon powder) is required according to the pollution of the tank liquid; the filter element of the filter pump should be replaced every two weeks;
4) Major treatment procedure: A. 取出陽極, 倒出陽極, 清潔陽極表面的陽極膜, 然後放入桶中包裝銅陽極, 用微蝕刻劑將銅角表面粗糙化為均勻的粉紅色, 乾燥後用水沖洗, 將其放入鈦籃中，並放入酸槽中使用. B. 將陽極鈦籃和陽極袋在10%鹼性溶液中浸泡6-8小時, 用水沖洗並乾燥, 然後浸泡在5%的稀硫酸中, 乾燥後用水沖洗, 可隨時使用； C. 將儲罐液體轉移至備用儲罐, 添加1-3ml/L 30%過氧化氫, 開始加熱, 當溫度約為65度時，打開空氣攪拌, 保持空氣攪拌2-4小時； D. 關閉空氣攪拌, 以3-5g的速率將活性炭粉末緩慢溶解到槽液中/L. 解散完成後, 打開空氣攪拌，保持溫度2-4小時； E. 關閉空氣攪拌和加熱 , 讓活性炭粉末慢慢沉澱到罐底； F. 當溫度下降到40度左右時, 使用10um聚丙烯濾芯和助濾劑粉末將罐液過濾到乾淨的工作罐中, 打開空氣攪拌, 然後放入陽極, 掛電解板, 在0的低電流密度下電解.2-0.5ASD 6-8小時. G. 實驗室分析後, 調整硫酸含量, 儲罐中的硫酸銅和氯離子達到正常工作範圍； 按霍爾後電解板的顏色均勻, 電解可以停止, 然後在1-1的電流密度下進行電解膜處理.5ASD 1-2小時, 並且在陽極上形成均勻層. 具有良好附著力的緻密黑磷膜足够； 我. 試鍍可以.
5) The anode copper ball contains 0.3-0.6%磷, the main purpose is to reduce the anode dissolution efficiency and reduce the generation of copper powder;
6) When supplementing drugs, 如大量硫酸銅和硫酸； 加入後用小電流電解； 補充硫酸時注意安全, and when adding a large amount (above 10 liters), 它應該慢慢地分成幾次. 補充 否則, 鍍液溫度過高, 輕試劑的分解將加快, and the bath will be polluted;
7) Special attention should be paid to the addition of chloride ions, because the chloride ion content is very low (30-90ppm), 在添加之前，必須用量筒或量杯準確稱量； 1ml鹽酸含有約385ppm的氯離子,
8) Calculation formula for drug addition:
Copper sulfate (unit: kg) = (75-X) × tank volume (liter) / 1000
Sulfuric acid (unit: liter) = (10%-X) g/L × tank volume (liter) or (unit: liter) = (180-X) g/L × tank volume (liter)/1840
Hydrochloric acid (unit: ml) = (60-X) ppm × tank volume (liter)/385

3.3 Acid degreasing
1) Purpose and function: remove the oxides on the copper surface of the circuit, 油墨膜的殘留膠水, 並保證銅與圖案電鍍銅或鎳之間的結合力.
2) Remember that acid degreaser is used here, 為什麼不使用鹼性脫脂劑呢？鹼性脫脂劑比酸性脫脂劑好? 主要是因為圖形油墨不耐鹼，會損壞圖形電路, 電鍍前只能使用酸性脫脂劑.
3) Only need to control the concentration and time of the degreaser during production. 脫脂劑濃度約為10%, 時間保證為6分鐘. 稍長一點的時間不會有不良影響； 工作流體, 按100平方米補充0.5-0.8L;

3.4 Micro-etching:
1) Purpose and function: Clean and roughen the copper surface of the circuit to ensure the bonding force between the patterned copper and copper.
2) Sodium persulfate is mostly used for micro-etching agents, 粗化率穩定均勻, 水洗性好. 過硫酸鈉的濃度通常控制在60 g左右/L, 時間控制在20秒左右. 公斤 銅含量控制在20克以下/L 其他維護和更換氣缸因銅下沉而受到微腐蝕.

3.5 Pickling
1) Function and purpose: To remove oxides on the board surface and activate the board surface, 總濃度為5%, 有些保持在10%左右, mainly to prevent the water from being brought into the tank and causing the sulfuric acid content to be unstable;
2) The acid leaching time should not be too long to prevent the surface of the board from oxidizing; after a period of use, the acid solution should be replaced in time when the acid is turbid or the copper content is too high to prevent contamination of the copper electroplating cylinder and the surface of the board;
3) C.P grade sulfuric acid should be used here;

3.6圖案鍍銅：也稱為二次銅, copper plating on the circuit
1) Purpose and function: In order to meet the rated current load of each line, 每條銅線和銅孔都需要達到一定的厚度. The purpose of copper plating the line is to thicken the hole copper and line copper to a certain thickness in time;
2) Other items are the same as the whole plate electroplating on PCB板.