1. Abstract

In high-voltage rectification applications, reverse voltage withstand margin, reverse recovery characteristics (Trr), and surge current capability (IFSM) are critical physical indicators determining system reliability. This white paper conducts an in-depth technical benchmarking of HVC Components (HVC) HVD series against comparable products from Germany's Diotec Semiconductor (2CL, BY, DD, HV series).

This report confirms that HVC's Multi-Junction Stack process and vacuum epoxy molding technology provide electrical characteristics equivalent to or superior to Diotec products across both the medium-to-high voltage range (8kV-20kV) and the ultra-high voltage range (above 100kV). The HVC HVD series serves as a Pin-to-Pin engineering-grade alternative for Diotec products in X-ray generators, industrial high-voltage power supplies, and pulsed power systems.

2. Device Architecture and Technology

2.1 Multi-Junction Stacking

• Diotec Process: Traditional processes using multiple discrete chips soldered or simple stacking.
• HVC Process: Advanced wafer-level multi-junction series technology with vertically integrated miniature PN junctions.

Advantage: Improves consistency of avalanche breakdown voltage by ~20% (EAS) versus competing products. Eliminates single-point failure from "hot spot" effects.

2.2 Vacuum Epoxy Molding

• Insulation Integrity: Vacuum molding eliminates micro-voids, blocking Partial Discharge channels under high electric fields.
• Thermal Management: Higher thermal conductivity enables operating junction temperatures up to 175°C.

3. Electrical Parameter Benchmarking

3.1 Static Characteristics: Reverse Voltage and Leakage Current

Example: 16kV specification (Diotec 2CL75 vs. HVC HVD-2CL75):

• VRRM: Both 16kV. HVC carries a 10%-15% engineering margin (actual breakdown often >17.6kV).
• Reverse Leakage Current (IR): Under 100°C, HVC's optimized passivation process suppresses IR drift to a lower level - critical for X-ray machine multiplier circuit stability.

3.2 Dynamic Characteristics: Reverse Recovery Time (Trr)

Test conditions: IF=0.5A, IR=1.0A, Irr=0.25A (Diotec BY series vs. HVC HVD-BY series):

• Standard Recovery: Consistent with Diotec.
• Fast Recovery: HVC special versions with Trr < 100ns, significantly reducing switching losses and EMI in high-frequency SMPS applications.

3.3 Extreme Characteristics: Surge Current (IFSM)

• 2CL85 example (50mA rated): HVC IFSM reaches 3.0A (8.3ms single half-sine wave) - 60x the rated current, demonstrating extremely strong transient surge withstand capability.

4. Cross-Reference Table

All HVC models have passed rigorous Fit-Form-Function (3F) verification for complete compatibility in dimensions, electrical function, and pin definitions.

5. Reliability and Compliance

5.1 Test Standards

• IEC 60747-2: Semiconductor devices - Discrete devices - Part 2: Rectifier diodes.
• MIL-STD-750: Environmental Test Methods for Semiconductor Devices.

5.2 Key Reliability Test Items

• High Temperature Reverse Bias (HTRB): 1000 hours at Tj=150°C, VR=80% VRRM.
  • Results: Leakage current change rate less than 10%, no breakdown failure.
• Temperature Cycling: -55°C to +150°C, 1000 cycles.
  • Results: No package cracks; electrical parameter drift within specifications.
• Pressure Cooker Test (PCT): 121°C, 100% RH, 2atm, 96 hours.
  • Results: No delamination, good insulation performance, confirming vacuum package hermeticity.

6. Application Engineering

6.1 Thermal Design

In high-current applications (such as BY4 at 1A), maintain moderate lead length or increase PCB copper area for auxiliary heat dissipation via leads.

6.2 Voltage Equalization Design

In ultra-high voltage (>100kV) series applications, parallel high-voltage resistors for static voltage equalization and high-voltage capacitors for dynamic voltage equalization to prevent uneven transient voltage distribution.

6.3 Layout and Insulation

PCB layout must strictly adhere to high-voltage creepage distance specifications. For applications >10kV, conformal coating or potting processes are recommended.

7. Conclusion

• Parameter Equivalence: Fully benchmarked against Diotec on VRRM, IAV, and Trr.
• Enhanced Robustness: Greater engineering margin in IFSM surge withstand and high-temperature leakage current characteristics.
• Supply Chain Advantage: As a Pin-to-Pin alternative, HVC effectively alleviates Diotec lead time pressure and reduces BOM costs.

For electronic system designs prioritizing high reliability and supply chain security, the HVC HVD series is a proven ideal engineering alternative.

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