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July 2016 • The PCB Magazine 15 tolerances. Taking this into consideration, an algorithm sorts the defects by whether they are in a critical area and eliminates oversensitivity alarms in less critical areas. For example, an AOI solution with intelli- gent panel understanding will ignore small de- fects in non-active areas of the design such as copper residues, ground or shielding which will not affect the functionality of the board. At the same time, it will seek the finest defects on criti- cal lines, spaces and pads. Although you cannot expect to find mul- tiple imaging technology and advanced panel understanding in every vendor's solutions, when you see their superior accuracy you will realize why it is becoming an AOI priority for PCB manufacturers. Automation-Assisted AOI Setup All PCB manufacturers want to reduce setup time in each phase of the production process. This is particularly true for producers of special- ty boards and prototypes with short runs that could require tens of new setups on a daily ba- sis. AOI setup is often a tedious, iterative pro- cess which now can be replaced with a faster, more accurate automated setup process. In AOI systems with automation-assisted setup, a non-expert operator can create an op- timal setup by visually categorizing true and false defects on the first panel of a job. Then the system automatically categorizes the de- fects into groups and sorts them according to severity, from the most critical to the least. It builds the optimal setup profile and automati- cally configures all relevant parameters accord- ingly. The result is an intuitive, optimal and much shorter setup process that is automati- cally implemented for the remainder of the run, increasing AOI throughput for the entire production cycle. Of course, automated setup can only be performed if the system can integrate with the manufacturer's CAM system and when the AOI solution provides the level of inspection accu- racy delivered by solutions with multiple imag- ing and intelligent panel understanding tech- nologies. Automated Optical Shaping Capabilities Another reason that advanced AOI capa- bilities are more important today is that now the high-quality inspection data from the AOI process can be used to integrate with automat- ed optical shaping (AOS) solutions. The most recent advances in 3D shaping mean that, in addition to shaping copper shorts where excess copper needs to be ablated, the latest AOS solu- tions can also shape opens where more copper needs to be added. Examples are shown in Fig- ures 3 and 4. When both shorts and opens are shaped in a one stop process, PCB scrap is virtually elimi- nated, even in the most advanced products such as any-layer HDI, complex MLB on mul- tiple lines areas, corners and pads. These new AOS solutions can overcome traditional limita- tions of manual shaping, enabling shaping on boards that could not be saved otherwise. FASTER, MORE ACCURATE AOI IS MORE IMPORTANT THAN EVER Figure 3: a) 3D image before shaping; b) 3D image after shaping. A B