AMT's Precise Die-Level Solution for 2.5D/3D IC Testing
Miniaturization and performance demands in ICs have led to complex 2.5D and 3D stacking, integrating multiple dies. Ensuring these "Known Good Stack Dies" (KGSDs) requires innovative testing. AMT's test handler tackles this with a new method for precise die-level testing.
2.5D and 3D IC packaging involve stacking multiple dies, either side-by-side on an interposer (2.5D) or directly atop each other (3D). While this compact design fosters exceptional performance, it presents tough testing hurdles. Conventional probing techniques struggle to achieve the necessary precision for reliable connections with the intricate network of electrical connections (interconnects) between the stacked dies.
Traditionally, KGSD testing for 2.5D/3D die has relied on wafer-level testing. While wafer-level testing offers advantages in terms of scale by testing multiple dies simultaneously, it fails to accurately replicate the final packaged environment. On the other hand, die-level testing offers a more comprehensive evaluation by focusing on individual singulated dies. However, the densely populated connection points (bumps or pads) in 2.5D/3D dies often lead to poor contact between the probing pins and the die's interconnect points, resulting in unreliable test results.
AMT's handler offers a new solution for precise die-level testing of 2.5D/3D chips. It uses a high-resolution camera and a vacuum chuck to meticulously capture connection points and precisely position the die, achieving 5μm accuracy. Additionally, the vacuum pressure applied by the chuck firmly holds the die in place, further enhancing test reliability by minimizing the risk of movement during the testing process.
One of the most significant advantages of AMT's innovative method lies in its ability to conduct parallel testing of multiple 2.5D/3D die. The test handler has the capability of simultaneously handling and testing up to 64 stacked and singulated dies. This feature maximizes equipment utilization and significantly improves testing throughput, leading to increased production efficiency. Furthermore, a key differentiator lies in the system's ability to perform testing directly on the thermally controlled stage, eliminating the need for temperature chambers commonly used with die-carrier methods. This not only simplifies the test setup but also mitigates the risk of dust particle contamination that can arise when using chambers for high/low-temperature testing.
The precise, efficient, and temperature-controlled nature of AMT's test handler translates into several benefits. Early identification of faulty 2.5D/3D die at the individual die level significantly reduces rework costs associated with defective packages. By eliminating these defective dies before the packaging stage, the method minimizes material waste and streamlines production processes. This translates to substantial cost reductions for manufacturers and ensures a higher yield of functional IC packages.
In conclusion, AMT's test handler represents a significant breakthrough in KGSD testing for 2.5D/3D die. By addressing the inherent challenges associated with these intricate packaging configurations, this innovative solution empowers engineers with a tool for precise, efficient, and reliable testing. This not only enhances the quality and yield of advanced IC packages but also paves the way for further advancements in high-performance computing applications that rely on 2.5D/3D technology.