Semiconductor Die Separation Trench for Precise Thickness Control

The patent applies preliminary action by forming the separation trench through the entire wafer thickness before thinning operations. This pre-established separation structure defines the final die thickness boundary, allowing subsequent thinning to proceed uniformly without affecting the precision of the thickness control. The separation trench acts as a predetermined stop point that ensures consistent thickness across all dies.

The patent segments the wafer into individual die regions by forming separation trenches that divide the continuous wafer structure. This segmentation creates discrete zones with clearly defined boundaries, enabling independent thickness control for each die region. The separation trench physically divides the wafer into separable units, each maintaining the precisely controlled thickness determined by the trench depth.

The patent implements feedback control by using the separation trench depth as a reference standard for die thickness. The trench depth is precisely controlled during formation, and this predetermined depth serves as a feedback reference that ensures each die achieves the target thickness. This closed-loop approach, where the separation structure itself provides the thickness reference, enables precise control of the load current path length and consequently the electrical resistance.

The patent replaces the conventional mechanical thinning process (etching or grinding) with a separation-based approach using vertically extending trenches. Instead of relying on mechanical removal processes that are difficult to control precisely, the invention uses the formation of separation structures that define thickness boundaries through non-mechanical or precisely controllable processes, thereby substituting the imprecise mechanical system with a more accurate method.

The patent performs the separation trench formation as a preliminary action before the final thinning and separation steps. By establishing the separation structures early in the process when the wafer is still at its original thickness, the trench depth becomes a fixed reference that guides subsequent thinning operations. This preliminary establishment of separation boundaries ensures that thickness consistency is maintained throughout the process while enabling efficient final separation.

The patent segments the wafer processing into distinct phases: first forming separation trenches to define die boundaries, then proceeding with thinning and separation. This segmentation of the manufacturing process allows each step to be optimized independently - the separation trench formation ensures precise thickness definition, while subsequent steps focus on efficient die release, thereby achieving both productivity and precision.