Thermal-expansion mismatch
Beginner
Different materials grow by different amounts when they warm up, which can bend or crack things glued together.
Novice
Silicon and circuit boards expand at different rates as temperature changes. On a small chip the difference is tiny; across a whole wafer it adds up to a large strain on the connections.
Expert
Shear strain grows with distance from the neutral point × , so it scales with part size. Large parts need compliant connectors, matched materials or careful assembly.
Explained in Wafer-scale and SRAM-heavy designs (Architectures).