Power electronics focuses on the conversion, control and distribution of electrical energy at high voltage and high current. Etching technology, including photochemical wet etching and semiconductor plasma dry etching, serves as a core microfabrication method for power electronic components. Power devices require excellent electrical conductivity, thermal dissipation, mechanical stability and long-term reliability under high temperature and high voltage operating conditions. Etching processes avoid mechanical stress and edge burrs which could trigger partial discharge, arcing or thermal failure. This technology supports prototype validation and volume manufacturing for silicon and wide-bandgap power semiconductors, power module packaging, energy storage converters, industrial power supplies and electric vehicle traction inverters.

Process Flow

1. Substrate preparation & cleaning: Remove surface grease, oxides and contaminants from metal foils, silicon carbide, silicon or ceramic substrates.
2. Photoresist masking: Laminating photoresist film, UV exposure and development to define protective patterns on workpiece surface.
3. Selective etching: Deploy wet chemical etching for thin metal structures; use plasma dry etching for semiconductor wafer trenching and isolation.
4. Photoresist stripping: Remove protective mask layer once target geometry is formed.
5. Post-treatment: Precision cleaning, surface passivation, annealing or plasma treatment to optimize electrical and thermal performance.
6. Reliability inspection: Dimensional metrology, insulation test, thermal cycling test and high voltage withstand verification.

Core Advantages

1. Burr-free sharp edges: Eliminates micro burrs that cause high-voltage corona discharge and electrical breakdown in power modules.
2. Ultra-low residual stress: No mechanical stamping force, preserving flatness of thin electrodes and heat spreaders under thermal cycling.
3. High thermal & electrical performance: Controlled surface topography ensures stable current conduction and efficient heat transfer.
4. High pattern repeatability: Consistent feature dimensions for mass production of power module components.
5. Dual process options: Wet etching for copper, nickel and alloy thin sheets; dry plasma etching for Si/SiC deep trench and isolation structures.

Application Fields

• Power module packaging: Lead frames, thin metal spacers, DBC substrate metal patterns, EMI shielding foils for IGBT / SiC MOSFET modules
• Power semiconductor wafers: Trench etching, mesa isolation and micro via structures for silicon and silicon carbide power chips
• Thermal management components: Micro-channel heat sinks, thin heat spreaders and heat dissipation meshes for high-power density packages
• Current-carrying conductive parts: Busbar shims, precision electrode plates, contact springs and current sensing foils
• Energy storage power converters: Micro filter plates, current sampling grids and precision metal gaskets for battery BMS power units
• EV traction power systems: Inverter internal shielding sheets, micro fluid restrictors and power sensing diaphragms

Design Considerations

1. High voltage design requires smooth, defect-free edge profiles; sharp micro-protrusions must be eliminated to prevent partial discharge.
2. Material selection must match high-temperature operation: copper, nickel, kovar, silicon and SiC are widely adopted for power electronics.
3. Strict residue removal is mandatory. Any residual etchant or particles may lead to leakage current and long-term device degradation.
4. Etch factor limits aspect ratio for wet etching; deep vertical trenches on semiconductor wafers require anisotropic plasma etching.
5. Thermal expansion mismatch between stacked layers should be considered to avoid delamination during power cycling tests.