Outsourced semiconductor assembly and test (OSAT) facilities provide packaging and test services to chip design teams. Their work happens at the back end of the flow, just before chips are integrated into end devices. From semiconductor fabless companies that don’t have the infrastructure for packaging and testing their devices to semiconductor foundries that focus primarily on the front end of the line, the demand for OSAT facilities is robust. In our smart everything world, where semiconductors are in such high demand, OSATs play a critical role in the electronics industry supply chain. They are essential in enabling access to the valuable data they host in their test environments.
Traditionally, collecting and analyzing test data from silicon devices being tested on automated test equipment (ATE) is nothing new. However, historically, it’s been a manual process that hasn’t happened in real time. As such, the insights gleaned often come too late to make a difference to the end product. Typically, a technician on the test floor at the OSAT produces Standard Test Data Format (STDF) files from each tester only after each wafer is tested or after a lot or sublot worth of packaged devices has been tested before the data is uploaded into a cloud-based server environment. From there, the data can be accessed by analytics software. By the time the analysis is completed, however, it may be too late to address any issue before the affected dies are further along downstream in manufacturing. Even in cases where the dies in question can be intercepted, many more dies may have been impacted by that same issue. The amount of retest and related test costs required after determining the proper corrective action is significantly higher than if the issue was addressed in real time. There are also opportunities when using manual efforts for someone to intercept the test files containing the data, raising security questions.
Another important consideration is how vast and diverse the manufacturing and testing ecosystem can be. Manufacturing and test operations are often spread across the world, supporting the various stages of chip manufacturing. Independent suppliers continuously generate high volumes of various types of chip data in different formats. Managing this data is quite challenging on many levels, from collecting and storing it, to monitoring and aligning it for quality and, ultimately, analyzing it for useful insights. Therefore, moving to a real-time automated data collection process has many benefits.