BGA 设计 制程amp;amp;焊接问题分析专题讲座.pdf

BGA設計 ,製程及焊接問題分析 Prepared By : Forrest you Date: 2013.03.11 內容: 1. BGA 的定義及類型; 2. PCBA design; 3. BGA檢查方法; 4. 問題分類及原因分析; BGA 的製造流程示意圖 或flip chip process 3 BGA package manufacturing process 4 BGA Cross-section: 5 BGA 錫球的成型方式 6 BGA 封裝的發展: PoP /Stack die 的目的? 7 BGA 錫球的防潮要求: BGA 零件為何要採取防潮包裝? 受潮後的失效模式? 8 BGA 錫球的防潮要求: BGA 封裝的吸濕性. 9 Popcorn: 受潮或多次rework Popcorning causes the BGA package to expand below the die; resulting in an increase in size (and possibly bridging) of the solder balls in the center of the package as they are squished between the package and the board. 10 BGA VIA Pad 與 PCB Pad 設計要求 11 BGA/CSP 的置件精度問題: Normal BGA: 1.5mm/1.27mm/1.0mm/0.8mm/0.5mm Pitch micro BGA/CSP: 0.4mm/0.3mm/0.25mm/0.2mm Pitch 12 BGA Pad 設計的差異: SMD or Non-SMD ? 13 BGA Reflow 視頻 14 BGA 不良檢測分析方法: Side view X-ray CSAM Cross-section 案例: PoP BGA (下層BGA) Open 15 BGA 製程不良: Mounting shift 置件位移Open 16 BGA 製程不良: Reflow 溫度不足或時間不夠 從BGA solder joint 高度判斷reflow 溫度是否足夠. 17 BGA 的不良類型原材不良 1. 缺錫球 2. 錫球的平整度 IPC 定義的平整度要求: 0.30 mm ball = 0.08 mm (ccc) 0.40 mm