Lead Free 标准制程介绍

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Scope 范围 This standard is a collection of visual quality acceptability requirement for electronic assemblies (e.g. PCBA). 该标准收集了电子组装件(如PCBA)的外观质量可接收标准。 Classification 等级 >>Class 1 -- General Electronic Products 等级1--一般电子产品 Includes consumer products, some computer and computer peripherals suitable for applications where cosmetic imperfections are not important and the major requirement is function of completed electronics. 包括消费类产品, 某些计算机和计算机外围设备.用于这些产品的印制板其 外观缺陷并不重要,主要要求是印制板的功能.
Standardized outline for joint of PTH components including top and bottom side are acceptable for tin-lead and lead-free
标准的通孔元件焊点即可介绍(包含Top, Bottom面)
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Lead Free Workmanship Standard
Prepared by Changdeng Lin
Flextronics Corporate Presentation
Training Introduction
2013/4/24
• Purpose 目的 1. To provide a basic lead free knowledge for visual quality acceptability requirement for electronic assemblies. 提供了关于电子组装件的无铅外观质量可接收标准的基础知识。 2. To provide comparison of workmanship standard between Tin-Lead and LeadFree product. 提供有铅与无铅产品工作质量标准的区别．
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Flextronics Corporate Presentation
Solder Joint Requirement Discrepancy
2013/4/24
3. BGA Components
Tin-Lead:
Collapse solder ball are not acceptable. 锡球坍塌不可接受.
• Reference Document 参考文件 IPC-A-610D Acceptability of Electronic Assemblies.电子组装件接受标准.
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Flextronics Corporate Presentation
IPC-A-610D Introduction
2013/4/24
Lead-Free:
Collapse solder ball are acceptable. 无铅制程中允许焊球坍塌.
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Flextronics Corporate Presentation
Solder Joint Requirement Discrepancy
2013/4/24
4. PTH Components
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Flextronics Corporate Presentation
IPC-A-610D Introduction
2013/4/24
>>Class 2– Dedicated Sevice Electronic Products. 等级2--一专用服务电子产品. Includes communications equipment, sophisticated business machines, and instruments where high performance and extended life is required and uninterrupted service is desired but not critical. Certain cosmestic imperfections are allowed. 包括通讯设备,高级商用机器和仪器.这些产品要求高性能和长寿命,同时希望能 够不间断地工作,但这不是关键要求.允许有某些外观缺陷.
Flextronics Corporate Presentation
Solder Joint Requirement Discrepancy
2013/4/24
Lead Free: •The bottom of the tear is visible. 可见的热撕裂的底部 • The tear or shrink hole does not contact the lead, land or barrel wall. 热撕裂或收缩孔不触及到引脚，焊盘或通孔内壁.
Lead-Free:
Lead free alloys are more likely to have: • Surface roughness (grainy or dull). • Greater wetting contact angles. 无铅合金呈现以下特点： 表面粗糙(颗粒状或灰暗色)． 润湿角较大.
Lead-Free:
Lead free alloys are more likely to have: • Surface roughness (grainy or dull). • Greater wetting contact angles. 无铅合金呈现以下特点： 表面粗糙(颗粒状或灰暗色)． 润湿角较大.
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Flextronics Corporate Presentation
Solder Joint Requirement omponents
Tin-Lead:
Typical tin-lead connections have from a shiny to a satin luster, generally smooth appearance and exhibit wetting as exemplified by a concave meniscus between the objects being soldered. The wide range of solder alloys in use may exhibit from low or near zero degree contact angles to nearly 90° contact angles as typical. 典型的有铅焊点呈现光泽，光滑的表面，并使焊盘 与焊接零件有良好的弯月型润湿，表面形状呈凹面状. 焊点形成一个小于或等于90度的连接角．
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Flextronics Corporate Presentation
Solder Joint Requirement Discrepancy
2013/4/24
Connatural Property For Lead Free Solder Joint
•Surface roughness (grainy, dull or ruffly), sight crack. It is caused by connatural property of solder alloys. Can not be decided for defect. 无铅焊点表面灰暗，常有起皱和轻微裂纹，这是 材料固有特性，一般不能判断为缺陷。 •More larger void in inner solder alloy. 25% or less voiding is acceptable. It will not affect component reliability 无铅焊点内部孔洞较大，只要不超过体积的25 ％即不能判断为缺陷，孔洞不影响可靠性。 •Less Fillet lifting caused by shrinking of lead free solder alloy is acceptable while it should meet wetting and visual requirement. 无铅通孔插装焊点会有收缩导致的焊角翘离，只要 润湿和外观良好，一般不能判断为缺陷。
Normally, Class 2 is used in our company.
本公司一般用二级标准
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Flextronics Corporate Presentation
IPC-A-610D Introduction
2013/4/24
>>Class 3– High Performance Electronic Products. 等级3--一高性能的电子产品. Includes the equipment and products where continued performance or performance-on-demand is critical. Equipment downtime cannot be tolerated and must function when required, such as in life support items or flight control systems. Assemblies in this class are suitable for applications where continued performance or performance –on-demand is critical. 持续包括要求连续工作或所要求的性能很关键的那些设备和产品.对这些设备(例 如生命支糸统或飞行控制糸统)来说,不允许出现停机时间,并且一旦需要就必须工作. 本等级的印制板适合应用在那些要求高度质量保证且服务是极其重要的产品.