元器件贴放过程优化:CMM和AOI的比较

Choosing CMM or AOI When Optimizing Component Placement

随着电路板以及元器件几何尺寸的缩小,印刷电路板装配中的质量控制水平也越来越重要。同时,这些尺寸很小的元器件非常脆弱,对贴放设备的挑战也越来越严峻。在线自动光学检验系统(AOI)可以在器件贴放完成之后进行检验、核查和测量,对于大多数标准的电路板结构而言,这样的系统有助于保证产品质量。而坐标测量机(CMM)对工艺过程的定量分析可以保证贴片过程处于最佳状态,这样AOI就可以对工艺过程的质量进行评估。上述这两种工艺过程的定性和定量分析对整个工艺控制中而言都必不可少。

The importance of quality control in printed circuit board (PCB) assembly is intensifying in proportion to the shrinking geometries of boardsand components. The challenge for placement equipment is also increasing as these shrinking components are extremely fragile. Inlineautomatic optical inspection (AOI) systems used for inspection, verification and measurement after component placement can help maintaina level of quality that seems to work well for most standard board configurations.AOI checks the process in action and the CMM inspection is more time-consuming, but delivers highly accurate variable data required forgaining control of the process and for statistical trend analysis. The CMM quantifies the process to ensure placement is working at optimumperformance so the AOI can qualify the process. Both process qualification and quantification are needed for complete process control.