【摘要】：對于軍工電子產(chǎn)品而言,如何在采用有鉛制程的情況下焊接有鉛、無鉛元器件并保證其可靠性已成為軍工單位迫切需要解決的問題。本文是以有色金屬材料學(xué)科為理論指導(dǎo),在試驗的基礎(chǔ)上,首先對有鉛無鉛混裝工藝的軍工電子產(chǎn)品的各個工藝流程的參數(shù)進行了控制,包括印刷參數(shù)、貼裝參數(shù),回流焊接參數(shù)等,完成了SMT有鉛焊膏下有鉛、無鉛元器件的混裝焊接;其次對試驗PCB板進行了可靠性驗證試驗,包括溫度循環(huán)試驗和振動試驗,最后通過使用X-Ray檢測儀對焊點進行檢測,用金相顯微鏡分別對不同焊端鍍層的元器件的焊點形態(tài)及合金層進行分析,以達到生產(chǎn)過程的穩(wěn)定、可控、可靠,使相應(yīng)工藝具有可操作性、廣泛性和一致性。本文在試驗中發(fā)現(xiàn)在成分為Sn62Pb36Ag2的有鉛焊膏焊接有鉛元器件、鍍層為純錫、鎳鈀金、錫銀銅等鍍層的無鉛元器件的條件下,在嚴格控制焊接溫度窗口在235±5℃之間,大于有鉛焊料熔點(179℃)的回流時間為80s左右,大于220℃的時間至少為4052+-秒時,能保證得到有效的Cu6Sn5合金層的厚度在4um范圍內(nèi),此混裝焊接可滿足軍用電子產(chǎn)品的可靠性。
[Abstract]:For military electronic products, how to weld lead, lead-free components and ensure their reliability has become an urgent problem to be solved by military industry units. Based on the theory of nonferrous metal materials, this paper controls the parameters of various technological processes of lead-free military electronic products, including printing parameters and mounting parameters, on the basis of experiments. Reflux welding parameters and so on, completed the SMT lead solder paste with lead, lead-free components mixed welding; Secondly, the reliability test of PCB plate is carried out, including temperature cycle test and vibration test. Finally, the solder joint is detected by using X-Ray detector. The solder joint morphology and alloy layer of the components deposited on different welding ends were analyzed by metallographic microscope in order to achieve the stability, controllability and reliability of the production process, and make the corresponding process operational, extensive and consistent. In this paper, it is found that under the conditions of lead-free components with lead soldering paste and pure tin, nickel, palladium, tin, silver, copper and so on, the welding temperature window is in the range of 235 鹵5 鈩，

本文編號：2406991