The placement of devices in SMT lines becomes even more demanding. Part sizes are being reduced at an alarming rate, and at the same rate the need for novel automated verification ideas is growing. The concept of inspection such as AOI is not new, but even today there remains some confusion over what we can expect from this technology.
In Europe, AOI is still a relatively new and misunderstood technology, fraught with many incorrect or ill-informed views and claims. Despite the large number of AOI suppliers, only around 30% of board assemblers actually use this technology. Frequently, old beliefs and installed ideas regarding test strategies become barriers to change. Of course, if significant investment has been made inother technologies, it is at times difficult to change in favor of AOI – or is it? This depends on how we viewAOI. In fact, we believe that AOI can become an extremely va-luable tool as part of an inte-grated verification strategy alliedwith other methods. Users generally fall into five basic categories regarding their individual perception of AOI:
- a) Some believe that AOI does not offer any benefits to their process. They either want, or need, to invest in test and other inspection tools. They feel it is possible to make the process perfect by buying better process equipment and controlling the process variables.
- b) If AOI worked it would be great. They tried it years ago, but it was useless. Nothing has changed, it is more trouble than it is worth. A manual inspection process is all we need.
- c) The current grey-scale machines are ok and can make some contribution to my test strategy, but theyare not easy to use or repeat-able enough. False calls are a problem.
- d) The colour-highlight system out-performs grey scale, but is costly to implement.
- e) AOI is excellent, it would be impossible to effectively run production without this technology.
From these considerations it becomes clear that the AOI systems supplier’s task is quite simply one of ongoing education. It is important that users stop thinking of AOI as a simple verification tool, but rather as an in-line process-improvement means, and ultimately as a quality-enhancement tool. To do this, we must turn the database into a data acquisition instrument for other equipment as well. We need an integrated line level solution link to the factory level networks. We are developing OCR, thus facilitating traceability which is also vital.
With such a view, it is imperative that we dispel the myths surrounding AOI in production. Users need to be aware of every angle and, most importantly, that AOI is not a „fit & forget“ solution. However, once integrated into a line, it will become apparent that productiv-ity increases. We believe that by building a strong relationship between the users and ourselves, through training and service, the necessary support and education is assured.
Generally, in articles marked with the Spotlight sign we provide insight and experience in an opinion-based style. Every Spotlight item therefore reflects the opinion of its author(s).
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