The laser cutting process and edge effect control for ultra-thin ferrite cores represent a core technical challenge in the manufacturing of high-frequency magnetic components. As electronic devices evolve toward higher frequencies and miniaturization, ferrite core thicknesses have been reduced to millimeter or even submillimeter scales. Traditional mechanical cutting often causes brittle fractures and geometric inaccuracies due to stress concentration, whereas laser cutting, with its non-contact nature and high energy density, enables precision processing of ultra-thin ferrite materials. However, the instantaneous high temperatures generated during laser cutting can induce heat-affected zones (HAZ) and lattice distortions, exacerbating magnetic domain structure damage near the cutting edges. This degradation impacts the high-frequency magnetic permeability and loss characteristics of the core, necessitating deep alignment between process parameters and material properties.

Optimizing laser cutting requires coordinated regulation of pulse frequency, scanning speed, and power density. For instance, when using nanosecond pulsed lasers, maintaining a repetition frequency range of 20–50 kHz alongside a scanning speed of 6–8 m/s balances cutting efficiency with reduced thermal accumulation. Experimental results indicate that excessive single-pulse energy (e.g., exceeding 0.8 mJ) triggers microcrack propagation at the edges. Gradient energy density control technology, achieved through dynamic adjustment of the laser spot diameter (gradually varying from 20 to 50 μm), enables more uniform stress distribution in the molten zone. Additionally, laminar-flow-assisted gas (e.g., nitrogen) effectively suppresses oxide layer formation, reducing cutting surface roughness to Ra ≤ 1.6 μm.

Edge effects primarily manifest as magnetic performance degradation near the cutting surface, governed by multiscale coupling mechanisms. Microscopically, laser-induced thermal shock causes localized amorphization of the spinel structure at ferrite grain boundaries, forming magnetic dead zones approximately 5–15 μm thick. At the mesoscale, thermally induced stress exacerbates domain wall pinning, increasing high-frequency eddy current losses. Studies reveal that adjusting the laser cutting angle from vertical incidence to 75° oblique cutting leverages lateral ablation to remove thermally damaged layers, reducing magnetic permeability loss in the effective magnetic circuit cross-section from 12% to below 4%. This spatial geometric optimization offers a novel approach to edge effect mitigation.

Composite process innovations demonstrate significant potential for active edge effect suppression. Post-laser-cutting low-temperature plasma annealing (300–400°C in an argon environment) restores microstructural order at the cutting surface, recovering the core’s power loss density to over 92% of the uncut material. Another advanced approach integrates laser-waterjet hybrid processing, where real-time water-cooling compresses the HAZ thickness to below 3 μm, while hydraulic removes molten slag and enables reconstruction of magnetic domain structures. A case study on high-frequency transformers showed that cores processed with this hybrid method exhibited an 18°C reduction in temperature rise and a 23% improvement in Q factor at 2 MHz compared to traditional laser-cut counterparts.

Future advancements will focus on intelligent closed-loop process control. Integrating online spectral monitoring systems to analyze plasma radiation characteristics during cutting enables dynamic laser parameter adjustments to compensate for material batch variations. Deep learning algorithms can autonomously establish cutting quality prediction models, such as automatically matching optimal pulse waveforms based on ferrite compositions (e.g., MnZn/NiZn systems). As femtosecond laser costs decline, their ultra-short pulse (10^-15-second level) characteristics promise to eliminate thermal conduction-type edge effects fundamentally, paving the way for atomic-level precision in ultra-thin ferrite core processing.