UGPCBのロゴ
Enig Immersion Goldプロセスには高い平坦性の利点があります, 均一, はんだや耐食性, さまざまな電子製品のPCB表面処理プロセスで広く使用されています.
EnigはImmersion Goldとも呼ばれます. PCBの化学ニッケル含有量は一般にで制御されます 7-9% (中リン). 化学ニッケルリン含有量は低リンに分割されます (マット), 中リン (セミグロス) そして高いリン (明るい). リン含有量が高いほど, 酸耐性抵抗が強いほど. 化学ニッケルは、銅の化学ニッケルに分けられます, 銅および化学ニッケルパラジウムプロセスの化学ニッケル. 化学ニッケルの一般的な問題はそうです “黒いパッド” (多くの場合、黒いディスクと呼ばれます, ニッケル層は灰色または黒に腐食しています, はんだき性を助長しません) または “mud crack” (fracture). The gold in enig can be divided into thin gold (replacement gold, thickness of 1-5u ″) and thick gold (reducing gold, thickness of enig can reach more than 25 microinches and the gold surface is not red). UGPCB mainly produces Enig thin gold PCB.
Process flow of Enig Immersion Gold PCB
Pre-treatment (brushing and sandblasting) – acid degreaser – Double wash – micro-etch (sodium persulfate sulfate) – Double wash – preimmersion (sulfuric acid) – activation (Pd catalyst) – pure water wash – acid wash (sulfuric acid) – pure water wash – chemical nickel (Ni/P) – pure water wash – chemical gold recovery – pure water wash – super pure hot water wash dryer
ENIG Immes Gold PCB and key process control
1. Remove oil cylinder
PCB nickelized gold is usually used for pre -treatment of acidic oil removal agents. Its role is to remove mild oil and oxides of copper surfaces, achieve the purpose of cleaning and increased wetting effect. Easy to clean the board.
2. Microlytic cylinder (SPS+H2SO4)
The purpose of slight erosion is to remove the residual residue of the copper surface oxidation layer and the pre -process, maintain fresh copper surface and increase the closeness of the chemical nickel layer. The micro -etching liquid is acidic sodium sulfate solution (NA2S2O8: 80 ～ 120g/L; sulfuric acid: sulfuric acid: 20 ～ 30ml/L). Because copper ions have a greater effect on the micro -eroding rate (the higher the copper ion, the more copper surface oxidation will be accelerated. The depth is 0.5 に 1.0 μm. When changing the cylinder, it often retains 1/5 cylinder parent liquid (old liquid) to maintain a certain copper ion concentration.
3. Pre -immersion cylinder
The pre -immersed cylinder only maintains the acidity of the activated cylinder and enters the active cylinder under the fresh state (anaoamide) 新鮮な状態の下 (嫌気性). 硫酸塩の事前に浸漬されたシリンダーは、事前に浸漬された剤として使用されます. 濃度は、活性化されたシリンダーと一致しています.
4. 活性化されたシリンダー
活性化の役割は、パラジウムの層です (PD) 化学ニッケルの開始反応のための触媒結晶核としての銅表面上. その形成プロセスは、PdとCuの化学的置換反応です, そして、銅の表面はPDの層に置き換えられます. 実際には, 銅の表面を完全に活性化することは不可能です (銅の表面を完全に覆います). コストの面で, これにより、PDの消費が増加し、浸透やニッケルスローニッケルなどの深刻な品質の問題を簡単に引き起こします.
添付ファイル: 灰色の黒い堆積物が溝の壁と溝の底に現れるとき, the nitric slot is required. The process is: 1: 1 nitric acid, start the cycle pump for more than 2 hours or until the gray black sediment of the slot wall is completely removed.
5. Nickel sinking cylinder (nickel -sinking reaction)
Chemical nickel is a catalytic effect of PD. NAH2PO2 hydrolyze generates atomic H. 同時に, under the conditions of PD catalytic conditions, the H atom is restored to a single nickel and deposited on the naked copper surface (generally nickel thickness is 100-250U, the rate rate is generally, the rate is the rate, and the rate is the rate. Control at 6-8 μl).
Chemical nickel slot nitrate trough procedures: draw chemical nickel potion into a spare slot. The concentration of commercially available concentration is 65%, nitric acid with a nitrate concentration of 10-30%(V/V), open the filtration cycle or pose for at least 8 hours after at least 8 時間. After a few hours of static, check the bottom of the slot or the slot wall to be nitrated? If you do n’t clean it, you need to supplement the nitric acid until the nitrate is clean. After the nitrics are clean, you need to remove the nitric acid waste liquid and rinse it with water, and then open the tank with water for about 15 分 (at least twice). And turn on the circular filtration for 15 分, and check the water, pure water pH value (test strip or pH test) data in the tank (generally the pH value of pure water was washed between 5-7) and the conductivity (generally at 15US/ Below cm) is qualified.
6. ENIG cylinder (sinking gold replacement reaction)
The replacement reaction Immersion Gold can usually reach the limit thickness for 30 分 (generally the gold thickness is 0.025-0.1 μm), and the rate is controlled at 0.25-0.45 μm/min). Due to the low content of Immersion Gold liquid AU (generally 0.5-2.0g/L), the diffusion speed and inner layer distribution of the PCB sinking gold solution affect each other Difference. 一般的に言えば, it is normal to be 100%higher than the gold thickness of the large area of PAD. Shen Jin’s thickness requirements can control the gold thickness by regulating temperature, time or increased gold concentration. The larger the golden cylinder, より良い, not only the small changes in the AU concentration are conducive to the control of the gold thickness and can extend the cylinder cycle.
Precautions for ENIG Immes Gold PCB Manufacturing
1. When the dense spacing of soft board lines is less than 0.1 mm, the activation time should be controlled between 60~90 seconds, and Pd2+should be controlled between 10~15PPM. If nickel cannot be deposited, or there is a small piece in a board or a thin gold deposit on the circuit, it indicates that the activation concentration or time is insufficient.
2. The test plate was degreased, micro etched, pre dipped and activated. After the activation treatment, the Pd layer on the Cu surface was observed: the surface was grayish white with moderate activation (neither too much activation turned black, nor too little activation turned the color of Cu), and then nickel gold was melted without missing plating and infiltration, indicating that the activator had good selectivity.
3. Check whether the anode protection voltage is normal before production. If it is abnormal, check the cause. The normal voltage protection is 0.8~1.2V;
4. Before production, 0.3〜0.5dm2/l裸の銅の覆われたプレートは、ニッケルバスのめっきを開始するために使用する必要があります. 生産中, 負荷は0.3〜0.8dm2/lの間でなければなりません. 負荷が不十分な場合, ドラッグシリンダープレートを追加するものとします. アンチカソード沈殿装置の電圧はに設定されています 0.9 V. 電流が超えたとき 0.8 あ, タンクが裏返されます, ジョイントは定期的にチェックする必要があります.
5. シリンダーは、通常のアクティビティとパラメーターを確保するために30分前にドラッグされる必要があります. ラインが停止した後, ニッケル浴の温度は下に落ちます 60 ℃. 加熱中, 循環または空気の混合を開始するものとする. 生産中, ニッケルバスの暖房エリアで空気の攪拌を有効にするものとする, そして、プレートの敷設のエリアは、空気の攪拌から解放されなければならない;
6. 非導電性穴のニッケルゴールドメッキ: パラジウムが多すぎると、直接の電気めっきまたは化学銅に残っています, そして、ニッケルバスアクティビティが高すぎます. 塩酸酸+チオウレアが使用されている場合, 溶液の組成: チオレア20〜30g/l, 分析的純粋な塩酸10〜50ml/l, および酸脱脂剤1ml/l. 動作条件: 4〜5分; 温度は22〜28℃です, 硫酸ナトリウムはわずかにエッチングされています 80 g/l, 硫酸は20〜50 ml/lです. 別の方法は、エッチング後にソリューションを浸すことです (sulfuric acid: 100ML/L+Thiourea: 20g/l+硫酸菌: 60g/l), そして、スズを削除します, 3つのカウンターカバーの水洗浄を通過してから、ニッケルゴールドの溶融ライン全体を通過するか、プロセスが青色の荷重→チオウエアに浸されています (スイング) →洗浄 (一度) →プレートを降ろします (スクラッチしないように注意してください) → placing it in a basin filled with clean water (not in the air) → passing through the brush mill → the first micro corrosion spraying → water spraying → no need to grind the plate → air drying → loading the plate → normalizing nickel gold.
7. If the nickel deposition rate is ≥ 4MTO (the supplement amount is greater than the multiple of the cylinder opening amount), the nickel deposition rate will slow down with the increase of MTO, the gold deposition rate will slow down due to the surface activity of the nickel layer, and the plate after gold deposition will be dark. The gilding time shall be long. If the gilding liquid is replaced, the appearance shall be normal. If it is nickel or gold bath is polluted, and the activity is poor when it passes through the nickel gold bath, the gold loading rate is slow and it is difficult to deposit gold or the gold surface is colorless. 加えて, the gold surface is light white, not yellow, and slightly inferior. There are grey holes in the nickel plating plate when it comes out from the gold plating normally, and the activity of the gold bath is usually insufficient (注記: the gold layer is darkened due to organic pollution, the gold content is increased or the gold deposited for a longer time is not yellow).
8. If the nickel sink contains high phosphite (the nickel sink is gray), the nickel deposition thickness will remain unchanged (no reaction) for a long time. 一般的に, the content of sodium phosphite (NaHPO3) is controlled at<120g/l. If it reaches ≥ 120g/l, new solution shall be prepared.
9. ニッケルメッキがありません – つまり, ニッケルの薄い層が堆積し、ニッケル層は白です. これからは、ニッケルバスのバス溶液が活動が不十分であることがわかります. この方法は、タンクをドラッグしてエージェントDを追加して、ニッケルバス溶液の活性を活性化することです.
10. ニッケルゴールドの挿入物を引き出し、硝酸+塩酸で除去する.
11. ニッケル堆積物が黒い場合 (染色), 現時点では金の堆積の速度が遅くなります, その後、堆積物からの金表面は赤と黄色になります (赤と酸化).
12. ニッケル溶液のpH値が高いほど, リン含有量が低いほど. MTOが高いほど, pH値が高いほど、降水速度が遅くなるはずです.
13. The gold bath solution has low gold concentration and long service life or is not clean after washing (easy to cause gold oxidation). The liquid medicine has a long service life and high impurities (the gold surface is speckled).
14. When the gold is thin, やり直すことができます. The rework method is: pickling (1-2 分) →洗浄 (1-2 分) → gold precipitation.
15. The boards should be dried within half an hour after gold deposition. The boards should be separated by white paper of appropriate size. The board holder must wear anti-static gloves. 乾燥後, the boards shall be transported to the board inspection room within 30 minutes to avoid gold oxidation caused by acid mist.
16. When the gold concentration in the gold precipitation tank is low and polluted by nickel, copper and metal impurities, the deposition rate will decrease (the activity will become poor) and even it is difficult to deposit gold (the gold precipitation time is long and the thickness cannot meet the requirements).
17. The working temperature of the solution must be kept fluctuating at about 2 ℃. If the amplitude is too large, flake coating will be produced.
18. The line shall be stopped for less than 8 hours for the nickel bath, and the cylinder shall be towed for 10-20 分, and the line shall be stopped for more than 8 時間, and the cylinder shall be towed for 20-30 分.
19. 生産中, air agitation shall be enabled in the nickel bath heating area.
20. Large load: rough, poor nickel deposition (spontaneous decomposition, rough nickel layer), and easy decomposition failure.
21. When Ni2+in the gold bath exceeds 500ppm, the appearance and adhesion of the metal will become worse, and the liquid medicine will turn green slowly. 現時点では, the gold bath must be replaced, which is very sensitive to copper ions. 20ppm以上の降水量は減速し、ストレスの増加につながります. ニッケルの沈殿後, 不快感を避けるために長い間任されるべきではありません.
ニッケルゴールドの一般的な問題の原因分析と対応する改善措置はリストされています. 絶え間ない学習と要約を通してのみ、製品技術をより徹底的に習得できます. 豊かな経験でのみ、問題をよりよく分析して決定できます. 同時に, 液体薬をより合理的に制御および維持することができます, 科学的に, 柔軟に効果的に, 高品質とリソースの無駄を減らすことに基づいて、高い効果を達成することで製品の利益率を改善します!
