Grooved Coil Electrode Structure to Prevent Peeling Under Bending

The patent applies local quality by creating a groove structure at the specific location where the external electrode connects to the body. This groove concentrates the electrode material in a localized region, increasing the contact area between the electrode and the body at the connection point while maintaining the overall compact structure. This localized structural modification enhances the bending strength without compromising the electrode connection reliability.

The patent introduces a dimensional change by forming a groove that extends into the body from the surface. This creates a three-dimensional connection structure instead of a simple surface-level connection. The groove provides additional depth and volume for the electrode to embed into the body, distributing the stress over a larger three-dimensional space rather than concentrating it at a two-dimensional surface interface.

The groove structure creates a localized region with enhanced mechanical properties. By concentrating the electrode material within the groove boundaries, the stress is distributed more evenly across the electrode-body interface rather than concentrating at the edge. This localized structural enhancement prevents stress concentration while maintaining reliable electrode connection.

The groove structure acts as a pre-designed stress-dissipating feature that cushiones the impact of bending forces before they can cause electrode peeling. The groove geometry is designed to absorb and distribute mechanical stress, providing a buffer zone that protects the electrode connection from harmful stress concentrations during operation.

The groove structure provides an additional dimensional pathway for stress distribution. Even with a relatively short extension portion, the groove creates vertical depth that allows stress to distribute in the z-direction (depth direction) rather than only in the planar directions. This three-dimensional stress distribution mechanism enables adequate bending strength without requiring a long extension portion that would complicate manufacturing.

The groove geometry parameters (depth, width, shape) are optimized to achieve the desired bending strength with a compact extension portion. By adjusting these parameters, the design achieves sufficient mechanical strength while keeping the extension length manageable for manufacturing purposes.