Super Barrier Rectifier Diodes: Low-Loss High-Reliability Power Solutions

Super Barrier Rectifier Diodes: Structure, Principle, and Engineering Applications

Fundamental Concept and Physical Principle

In the broad family of type of diode used in modern power electronics, the Super Barrier Rectifier Diode (SBR) stands out as a high-efficiency rectification device that has become popular in switch-mode power supplies, automotive electronics, LED drivers, and other energy conversion systems.

SBRs were developed to address a long-standing limitation of traditional Schottky diodes: excessive reverse leakage current under high reverse voltage and elevated temperature conditions.

The name “Super Barrier” originates from its unique structural design—by combining a PN junction barrier with a Schottky-like metal-semiconductor contact, along with multilayer epitaxial technology, SBRs achieve low forward voltage drop (Vf) while significantly reducing reverse leakage current (Ir) and improving reverse voltage capability (VRRM).

Physically, SBRs merge the low-barrier conduction of Schottky diodes with the high reverse blocking capability of PN junctions. When forward-biased, they behave like a Schottky device, conducting through a low barrier; when reverse-biased, the PN structure suppresses carrier migration, thus minimizing leakage.

Structural Design and Manufacturing Process

The advantages of SBRs stem from their composite barrier structure.

Their construction typically includes:

1.Metal Contact Layer

Provides a low-barrier conduction path, reducing Vf to 0.2–0.45V.

2.Super Barrier PN Structure

A shallow P-layer is introduced between the metal and the N-base region to suppress reverse leakage.

3.Multilayer Epitaxy and Field-Buffer Zones

In high-voltage SBRs, multilayer epitaxy distributes the electric field, enhancing VRRM.

The manufacturing process often involves epitaxial growth, ion implantation, and metallization. For high-power packages such as TO-220 or TO-247, the backside is plated with nickel and silver to reduce thermal resistance.

For example, a high-voltage SBR may be fabricated through:

 Epitaxial growth of an N⁻ layer on an N-type silicon substrate

 Ion implantation to form the P-region

 Metal deposition (titanium, aluminum, etc.) on the P-region surface

 Backside metallization

 Wafer dicing, wire bonding, and encapsulation

This design ensures both low conduction loss and high thermal stability during operation.

Electrical Characteristics and Performance Analysis

From datasheets, the following parameters are essential when selecting SBRs:

Forward Voltage Drop (Vf)

Typically 0.2–0.45V at rated current and 25°C—lower than 0.8–1.0V for fast recovery diodes.

Reverse Leakage Current (Ir)

At high temperature (125°C), SBR leakage is 3–5 times lower than that of Schottky diodes of similar ratings.

For example, a 200V SBR may have leakage of only tens of μA at 125°C, while a Schottky could reach hundreds of μA.

Reverse Voltage Rating (VRRM)

SBRs cover 40V–600V, far higher than the typical ≤200V range of standard Schottky diodes.

Reverse Recovery Time (trr)

Slightly longer than ultra-fast Schottkys, but sufficient for applications below ~200kHz switching frequency.

Operating Temperature Range

Most SBRs operate reliably from -65°C to +150°C, with some automotive-grade parts rated up to 175°C.

Classic Models and Application Examples

1.Diodes Inc. SBR10U200P5-13

Specs: 10A, 200V, Vf = 0.45V

Package: TO-220AC

Features: High efficiency, low leakage, suitable for high-temperature SMPS

Example: Used in a 200W industrial power supply output stage, boosting efficiency by ~1.5%

2.ON Semiconductor SBR3060CT

Specs: 30A, 60V, Vf = 0.49V

Package: TO-220AB dual common-cathode

Features: Low voltage, high current, ideal for DC/DC converter secondary rectification

Example: Automotive USB charging modules

3.Vishay SBRD10200

Specs: Dual 10A, 200V, Vf = 0.48V

Package: TO-263AB

Features: Dual-channel design allows parallel operation for lower thermal resistance

Example: LED streetlight drivers

Comparison with Other Types of Diode

To understand where SBRs fit, let’s compare them with other type of diode commonly used in power circuits:

Clearly, SBRs strike a balance between low Vf, high VRRM, and low leakage, making them ideal for medium-voltage, high-efficiency rectification applications.

Application Scenarios and Design Guidelines

1.Application Scenarios

Switch-Mode Power Supply Output Rectification

Used on the secondary side of AC/DC converters to improve efficiency and reduce heat.

Automotive Electronics

Reverse polarity protection and alternator rectification in 12V–48V systems.

LED Drivers

Improve efficiency after power factor correction (PFC) stages.

Solar Inverters

Enhance DC input rectification efficiency and reduce thermal dissipation.

2.Design Guidelines

Voltage Margin: Choose VRRM 1.5–2× the operating voltage.

Package & Thermal: Use TO-220/TO-247 for high current to improve cooling.

Parallel Operation: Possible for high current but ensure current sharing and thermal balance.

PCB Layout: Shorten high-current loops, increase copper thickness.

Technology Trends

SBR technology continues to evolve toward:

Higher Voltage Ratings: Expanding to 300V, 600V ranges to replace some FRD applications.

SiC-SBR Hybrid Devices: Combining silicon carbide material with SBR structure for high-voltage, low-Vf performance.

Integration with MOSFETs: In synchronous rectifiers, SBRs act as backup devices to prevent reverse conduction.

Super Barrier Rectifier Diodes are not meant to replace every type of diode, but rather to offer a well-balanced option for specific high-efficiency rectification needs. With their combination of low forward voltage, high reverse blocking capability, low leakage, and excellent thermal stability, SBRs are an ideal choice in designs where both efficiency and reliability are critical.

As semiconductor materials and fabrication processes advance, SBRs are expected to see wider adoption in automotive, industrial, and renewable energy applications.