1.1 本测试方法涵盖了测试完整表面安装装置（SMD）接头的粘接强度和层间应力兼容性的方法 1.2 一种完整的SMD接头包括:；SMD（LED、电阻器等）、PTF油墨焊盘（通常为银）、导电粘合剂（通常为银）、铆接化合物（非导电）和密封剂（非导电）。 ====意义和用途====== 4.1 现有测试方法 1995财年 ，虽然非常有用，但如果应用封装圆顶，则很难执行，并且不会揭示由于整体SMT接头中的机械应力不兼容而导致的可能故障。该芯轴弯曲试验将揭示各种粘合剂之间可能存在的机械应力不相容性，这可能会导致生产处理过程中或正常使用中的热循环过程中潜在的现场故障。 4.2 现有测试方法 F2750 不包括SMD附件的详细信息，仅说明导电迹线的导电性变化。 4.3 SMD类型、连接介质、电路基板和工艺变化的不同组合可以解释测试结果的显著变化。 4.4 印刷柔性电路或其部件的弯曲会影响其视觉外观、机械完整性或电气功能。本试验方法模拟制造、安装或使用过程中可能出现的条件。 4.5 弯曲测试可能具有破坏性，因此任何测试的样品都应被视为不适合未来使用。

1.1 This test method covers a means to test a completed Surface Mounted Device (SMD) joint for bond strength and inter-layer stress compatibility 1.2 A completed SMD joint includes; SMD (LED, resistor, etc), PTF ink land (typically silver), conductive adhesive (typically silver), staking compound (non-conductive), and encapsulant (non-conductive). ====== Significance And Use ====== 4.1 The existing Test Method F1995 , while very useful, is difficult to conduct if an encapsulating dome is applied, and does not reveal the possible failures caused by mechanical stress incompatibility in the overall SMT joint. This mandrel bend test will reveal possible mechanical stress incompatibility between the various adhesives which can result in latent field failures during production handling or with thermal cycling in normal use. 4.2 The existing Test Method F2750 does not include specifics for SMD attachments and only addresses the conductivity change of the conductive trace. 4.3 The different combinations of SMD types, attachment medias, circuit substrates and process variation can account for significant variation in test outcome. 4.4 Bending of printed flexible circuit or their components can affect their visual appearance, mechanical integrity or electrical functionality. This test method simulates conditions that may be seen during manufacture, installation, or use. 4.5 Bend testing may be destructive, therefore any samples tested should be considered unfit for future use.