【簡(jiǎn)介】
摘要:采用赫爾槽試驗(yàn)、哈林陰極法、貼濾紙法及穩(wěn)態(tài)陰極極化測(cè)量,研究了分別由ACTl和普通國產(chǎn)焦磷酸鹽配制的鍍銅液的性能差別,采用絡(luò)合能力指數(shù)(CAI)對(duì)不同品質(zhì)焦磷酸鉀的絡(luò)合能力進(jìn)行評(píng)價(jià)。結(jié)果表明,采用絡(luò)合能力指數(shù)高的ACTl焦磷酸鹽配制的鍍銅液,其分散能力、絡(luò)合能力和鍍層致密性、孔隙率均優(yōu)于以絡(luò)合能力指數(shù)低的普通焦磷酸鹽配制的鍍銅液。雜質(zhì)正磷酸根離子嚴(yán)重影響ACTl焦磷酸鹽鍍銅液的極化性能:隨著其質(zhì)量濃度增大,槽電壓升高,鍍液的絡(luò)合能力降低。三聚磷酸根離子對(duì)ACTl焦磷酸鹽鍍銅液的極化性能影響不大。
關(guān)鍵詞:電鍍銅;焦磷酸鹽;絡(luò)合能力指數(shù);分散能力;陰極極化;金相組織;孔隙率
中圖分類號(hào):TQl53.14 文獻(xiàn)標(biāo)志碼:A
文章編號(hào):1004—227X(2009)02—0008—04
Effect of pyrophosphate quanty on copper electroplating//SUN Song-hua*,WANG Jun,
Abstract:The performance differences between the Cu plating baths prepared respectively with ACTI and ordinary China—made pyrophosphates were studied by Hull cell test, Haring cell method,filter paper method and steady—state cathodic polarization measurement.The complexing capabilities of potassium pyrophosphates of different qualities were evaluated by determination of complexing capability index fCAI).The results showed that the CU plating bath prepared with ACTI pyrophosphate has higher throwing power and complexing capability than that prepared with ordinary pyrophosphate,producing Cu deposits with better compactness and less porosity.Orthophosphate ions,as impurities,greatly affect the polarization of ACTI pyrophosphate Cu plating bath.The increase in the mass concentration of orthophosphate results in an increased cell voltage and a decreased complexing capability of the bath. Tripolyphosphate ions have a slight effect on the polarization of ACTI pyrophosphate Cu plating bath.
Keywords:copper electroplatin9;pyrophosphate;complexing capability index;throwing power;cathodic polarization; metallographic structure;porosity
First-author’S address:Home Office of American ChemTech Inc.in Asia,Hangzhou 3 1 1 200,China
1 前言
銅鍍層廣泛用于鋼鐵件多層鍍覆以及鍍錫、鍍金、鍍銀等的“底”層,以提高基體金屬與鍍層的結(jié)合力。當(dāng)銅鍍層無孔時(shí),可大大提高表面鍍層的抗蝕性。目前,工業(yè)上最普遍的電鍍銅方法是使用含氰化物鹽類的鍍液[1-3]。氰化鍍液最大的缺點(diǎn)是具有毒性,在使用過程中對(duì)環(huán)境帶來危害。采用低毒或無毒的鍍銅方法是電鍍行業(yè)的發(fā)展趨勢(shì)。
焦磷酸鹽鍍銅工藝成分簡(jiǎn)單,鍍液穩(wěn)定,電流效率高,均鍍能力和深鍍能力較好,鍍層結(jié)晶細(xì)致,鍍速快,電鍍過程中沒有刺激性氣體逸出,是一種低毒、性能優(yōu)異的鍍銅方法[4-6]。焦磷酸鹽鍍液的主要成分是供給銅離子的焦磷酸銅和作為絡(luò)合劑的焦磷酸鉀,此兩者能相互作用而生成絡(luò)鹽焦磷酸銅鉀。焦磷酸鉀除了與銅生成絡(luò)鹽外,還有一部分游離于鍍液中,它不僅可使絡(luò)鹽穩(wěn)定,而且可提高鍍液的均鍍能力和深鍍能力。本文根據(jù)焦磷酸鹽鍍銅方法,比較了不同品質(zhì)的焦磷酸銅和焦磷酸鉀對(duì)鍍液及鍍層性能的影響,并分析了雜質(zhì)正磷酸根離子和三聚磷酸根離子對(duì)電鍍液的影響。
2 實(shí)驗(yàn)
2.1材料
ACTl焦磷酸鉀K4P207和ACTl焦磷酸銅 Cu2P207·4H20均由美國化學(xué)技術(shù)公司提供,并分別采用ACTl 2156-2002及ACTl 2157-2002標(biāo)準(zhǔn)檢測(cè)(以離子交換柱色譜法分離樣品中的焦磷酸鹽、正磷酸鹽、三聚磷酸鹽、三偏磷酸鹽和多聚磷酸鹽后,采用磷鉬酸喹啉重量法測(cè)定);普通焦磷酸鉀K4P207