TO-252 (DPAK) Package Dimension Details

TO-252 (also known as DPAK) is a surface-mount (SMD) power device package commonly used for medium-power devices such as MOSFETs and diodes. Below are its standard dimensions, structural features, and design considerations.

1. TO-252 Standard Dimensions (in mm)

2. Mechanical Structure Features

• 3-pin design (some models may have 2 pins):

  • Pin 1 (G/S): Gate (for MOSFET) or Anode (for diode).

  • Pin 2 (D): Drain (for MOSFET) or Cathode (for diode).

  • Pin 3 (Heat Sink): Electrically connected to the Drain (D), must be soldered to the PCB copper foil for heat dissipation.

• Heat Dissipation Method:

  • Heat is dissipated through the PCB copper foil (recommended ≥2cm² copper area).

  • High-power models may require additional heat sinks (such as the TO-252-3L variant).

3. Comparison with Similar Packages

4. Typical Device Models

5. PCB Design Recommendations

1. Pad Sizes (Recommended):

   • Heat Sink Pad: 4.5×4.5mm (minimum 3×3mm).

   • Lead Pads: 1.5×1.2mm (pitch 2.3mm).

2. Heat Dissipation Optimization:

   • Use 2oz copper thickness and multiple vias to enhance heat dissipation.

   • For high-power scenarios, external heat sinks may be needed (e.g., TO-252-3L variant).

3. Reflow Soldering Temperature Profile:

   • Peak temperature ≤260°C (for lead-free processes).

6. 3D Models and Drawings

• STEP Files: Can be downloaded from manufacturers' websites (e.g., TI, Infineon).

• Dimension Diagram:

  |-----------6.5mm-----------|
  | +-----------+             |
  | | TO-252    |             |
  | | (DPAK)    |             |
  | +-----+-----+             |
  

Conclusion

TO-252 (DPAK) is a widely used surface-mount package for medium-power devices, offering a compact and efficient solution for applications such as power management and DC-DC conversion. It provides excellent heat dissipation through its copper foil on the PCB and can handle current ratings between 10A and 50A. Proper PCB design, including appropriate pad sizes and heat dissipation considerations, is critical to ensuring the reliable performance of devices in TO-252 packages.

If you need more specific details about components or further assistance with your design, feel free to reach out!

TO-247 Package Dimension Details

TO-247 is a high-power discrete device package widely used for high-current MOSFETs, IGBTs, and diodes. Its design optimizes heat dissipation, making it suitable for high-power applications such as power supplies and motor drives. Below are the standard dimensions and key parameters.

1. TO-247 Standard Dimensions (in mm)

2. Mechanical Structure Features

• 3-pin (standard) or 4-pin (improved version):

  • TO-247-3: G (Gate), D (Drain), S (Source) or C/E (for IGBT).

  • TO-247-4 (Kelvin Pin): Adds an independent source pin to reduce switching losses (e.g., Infineon CoolMOS).

• Heat Sink (Tab):

  • Electrically connected to the middle pin (D/C), which needs to be insulated when mounted (e.g., using mica sheets and thermal grease).

• Mounting Method:

  • Fixed to the heat sink using M3 or M4 screws (insulating washers required).

3. Typical Device Models

4. Comparison with Similar Packages

5. PCB/Heat Dissipation Design Recommendations

1. Heat Dissipation Requirements:

   • Thermal resistance RθJA: Approximately 40°C/W without a heat sink, requiring forced air cooling or large heat sinks.

   • Recommended heat sink: ≥50×50mm aluminum finned heat sink (e.g., Aavid 7021).

2. Mounting Considerations:

   • Use insulating pads (e.g., mica) + thermal grease (thermal conductivity ≥3W/mK).

   • Screw torque: 0.5~0.6Nm (to avoid crushing the chip).

3. Pin Identification (from the front, left to right):

   • MOSFET: G (Gate) → D (Drain) → S (Source).

   • IGBT: G (Gate) → C (Collector) → E (Emitter).

6. Additional Considerations

For optimal performance and reliability, it is important to ensure proper heat management when using TO-247 packages, particularly for high-current and high-power applications. Additionally, following proper mounting procedures and using suitable thermal interfaces will ensure the longevity and efficient operation of the device.

TO-223 Package Dimension Details

TO-223 is a power device package that lies between TO-220 and SMD packages. It is primarily used for medium to low-power devices (under 10A), such as MOSFETs and voltage regulators. Its features include single-row through-hole and surface-mount compatibility, making it ideal for space-constrained PCB designs. Below are the detailed parameters and characteristics.

1. TO-223 Standard Dimensions (in mm)

2. Mechanical Structure Features

• Lead Form:

  • 3-pin single-row through-hole (similar to TO-220 but more compact).

  • Some models support surface-mount (SMD) with leads that can be bent for soldering.

• Heat Dissipation Design:

  • The metal heat sink is electrically connected to the middle lead (D/C), requiring insulation on the PCB.

  • Relies on PCB copper foil for heat dissipation (recommended ≥2cm² copper area).

• Mounting Method:

  • Through-Hole Technology (THT): Soldered through PCB holes.

  • Surface-Mount Device (SMD): Leads bent 90° for surface-mount soldering (ensure mechanical strength).

3. Comparison with Similar Packages

4. Typical Device Models

5. PCB Design Recommendations

1. Pad Dimensions (for SMD mode):

   • Heat Sink Pad: 5×5mm (minimum 3×3mm).

   • Lead Pad: 1.5×1.5mm (spacing 2.54mm).

2. Heat Dissipation Optimization:

   • Use 2oz copper thickness + multiple vias to enhance heat dissipation.

   • For high-power scenarios, small external heat sinks can be added (e.g., Aavid 573300).

3. Soldering Process:

   • Reflow soldering peak temperature ≤260°C (lead-free process).

6. 3D Models and Drawings

• STEP Files: Available for download from manufacturer websites (e.g., TI, ON Semi).

• Dimension Diagram:

|-----------10mm-----------|

TO-263 (D²PAK) Package Dimension Details

TO-263 (also known as D²PAK) is a surface-mount (SMD) power device package, commonly used for medium to high-power MOSFETs, voltage regulators, and diodes. It is designed to optimize heat dissipation and is ideal for applications requiring high current but limited PCB space (such as power modules and motor drives). Below are the detailed dimensions and characteristics.

1. TO-263 Standard Dimensions (in mm)

2. Mechanical Structure Features

• Pin Count:

  • 3 pins (Standard): G (Gate), D (Drain), S (Source), or corresponding polarity (diodes/regulators).

  • 5~7 pins (Enhanced): Some models add Kelvin source or sensing pins (e.g., TI's D²PAK-7).

• Heat Dissipation Design:

  • Bottom metal heat sink is electrically connected to the middle pin (usually D/C), requiring soldering to large copper areas on the PCB.

  • Relies on PCB heat dissipation (recommended copper area ≥4cm², 2oz copper thickness).

• Mounting Method:

  • Pure surface-mount (SMD) with reflow soldering, avoiding mechanical stress.

3. Comparison with Similar Packages

4. Typical Device Models

5. PCB Design Recommendations

1. Pad Dimensions (recommended):

   • Heat Sink Pad: 8×10mm (minimum 6×8mm), with multiple vias to enhance heat dissipation.

   • Lead Pad: 1.8×2.0mm (spacing 2.54mm).

2. Heat Dissipation Optimization:

   • Use 2oz copper thickness + vias (hole diameter ≥0.3mm) to connect to inner or backside copper layers.

   • For high-power scenarios, external heat sinks can be added (e.g., Aavid 581002).

3. Reflow Soldering Process:

   • Peak temperature ≤260°C (lead-free process), avoid uneven heating to prevent cold solder joints.

6. 3D Models and Drawings

• STEP/Downloadable Files: Available from manufacturers' websites (e.g., Infineon, ON Semi).

TO-264 Package Parameters Explained

The TO-264 is a high-power three-pin package, primarily used for high current MOSFETs, IGBTs, and high-voltage diodes. It is commonly found in industrial power supplies, renewable energy systems, and high-power inverters. Its size is larger than the TO-247, offering better heat dissipation, making it suitable for applications requiring 200A and above.

1. Standard Dimensions of TO-264 (Units: mm)

2. Mechanical Structure Features

• 3-pin design (Some models support 4 pins):

  • G (Gate), D/C (Drain/Collector), S/E (Source/Emitter).

  • 4-pin version: Adds Kelvin source (for optimized IGBT module driving).

• Heat Sink (Tab):

  • Electrically connected to the middle pin (D/C) and needs to be fixed using an M4 screw, with insulation treatment required.

• Installation Method:

  • Vertical or horizontal installation, typically used with large heat sinks (such as air-cooled or water-cooled heat sinks).

3. Typical Device Models

4. Comparison with Similar Packages

5. Heat Dissipation and Installation Design Recommendations

1. Heat Dissipation Requirements:

   • Thermal Resistance RθJA: Approximately 20~30°C/W without heat sink; forced cooling (such as air or water cooling) is required.

   • Recommended heat sink: ≥100×100mm aluminum finned heat sink (e.g., AAVID 0938 series).

2. Insulation Treatment:

   • Use mica sheets/ceramic pads + thermal silicone grease (thermal conductivity ≥5W/mK).

   • Screw torque: 0.6~0.8Nm (to avoid crushing the chip).

3. PCB Layout:

   • For high-voltage applications, ensure pin spacing ≥ 8mm to prevent creepage.

6. 3D Models and Drawings

• STEP/DXF Files: Available for download from manufacturer websites (such as IXYS, ON Semi).

• 7. Selection and Substitution Recommendations

  Applicable Scenarios:

  • Ultra-high voltage (≥1200V), high current (≥200A) industrial equipment.

  • Substitution for older packages like TO-3P.

  Substitution Options:

  • For higher integration, consider IGBT modules (e.g., Infineon FF600R12ME4).

  Summary

  The TO-264 package is the preferred choice for ultra-high-power discrete devices, with advantages including:

  • ✅ Very high current handling capability (500A+)

  • ✅ Dual-side heat dissipation design (when paired with large heat sinks)

  • ✅ Compatibility with high-voltage applications (6500V+)

TO-247 Plus Package Parameter Details

TO-247 Plus (or TO-247-4L) is an improved version of the standard TO-247, mainly optimized for heat dissipation and switching performance. By adding a Kelvin emitter pin (the fourth pin), it reduces gate loop interference, making it suitable for high-frequency, high-power applications (such as switch-mode power supplies and renewable energy inverters).

1. TO-247 Plus Standard Dimensions (Unit: mm)

2. Mechanical Structure Features

• 4-Pin Design:

  • Pin 1 (G): Gate (driving signal input).

  • Pin 2 (D/C): Drain (MOSFET) or Collector (IGBT).

  • Pin 3 (S/E): Power Source/Emitter (Main current path).

  • Pin 4 (Kelvin S/E): Independent detection pin used to reduce drive loop inductance and improve switching speed.

• Heat Dissipation Optimization:

  • The heat sink area is the same as the TO-247, but the internal layout has been improved to reduce thermal resistance (RθJC).

• Installation Compatibility:

  • The mounting hole distance is the same as the TO-247 (10.6mm), allowing for direct replacement (note the pin definition differences).

3. Comparison with Standard TO-247

4. Typical Device Models

5. Heat Dissipation and PCB Design Recommendations

1. Driver Circuit Design:

   • The Kelvin pin should be directly connected to the gate drive IC, avoiding shared routing with the power loop.

2. Heat Dissipation Requirements: (Further details on heat dissipation design may be included based on specific application needs.)

3. • Recommended Heat Sink: ≥50×50mm aluminum finned heat sink (e.g., Aavid 7021).

   • Thermal Materials: Ceramic insulating pads (thermal conductivity ≥3W/mK).

   3. PCB Layout Recommendations

   • Physically isolate the power loop (D-S) from the drive loop (G-Kelvin S) to reduce coupling interference.

   6. 3D Models and Dimensional Diagrams

   • STEP Files: Available for download from manufacturers like Infineon and ST (search for “TO-247-4L mechanical drawing”).

   • Pin Definition (viewed from the front, left to right):

   |-----------20.5mm----------|
   | +-----------------+       |
   | | TO-247 Plus    |       |
   | | (4 Pins)       |       |
   | +--------+--------+       |
   | | | | |                 |
   | G D/C S/E Kelvin S  | (Pin spacing 5.45mm)
   |__________________________|
   

   7. Selection and Replacement Recommendations

   • Applicable Scenarios:

     • High-frequency switching (>100kHz) or SiC/IGBT drive circuits.

     • Applications sensitive to switching loss (e.g., photovoltaic inverters, electric vehicle OBC).

   • Replacement Options:

     • If the Kelvin pin is not required, standard TO-247 can be used (with some performance sacrifice).

   Summary

   The core advantage of TO-247 Plus is the 4-pin Kelvin design, significantly reducing switching loss and oscillation risk, making it suitable for:

   • High-frequency, high-power circuits (e.g., LLC resonant converters).

   • SiC/GaN device driving (where low inductance loops are required).

   • Replacing standard TO-247 to improve system efficiency.

   Caution:

   • Match with a dedicated driver circuit (utilizing the Kelvin pin).

   • Heat dissipation design is compatible with TO-247, but pin definition differences should be noted.

TO-251 (IPAK) Package Detailed Parameters

TO-251 (also known as IPAK or TO-251AD) is a compact power device package, situated between TO-220 and TO-252. It is suitable for medium to low power MOSFETs, transistors, and voltage regulators. Its features include small size and low cost, making it ideal for space-constrained PCB designs.

1. TO-251 Standard Dimensions (unit: mm)

2. Mechanical Structure Features

• 3-pin design:

  • Pin 1 (G/B): Gate (MOSFET) or Base (Transistor).

  • Pin 2 (D/C): Drain (MOSFET) or Collector (Transistor).

  • Pin 3 (S/E): Source (MOSFET) or Emitter (Transistor).

• Thermal Design:

  • The metal heatsink is electrically connected to the middle pin (D/C), and proper PCB insulation should be ensured.

  • Relies on PCB copper foil for heat dissipation (recommended ≥2cm² copper area).

• Mounting Methods:

  • Through-hole mounting (THT): Pins inserted and soldered to PCB.

  • Surface-mount (SMD): Pins bent at 90° for surface-mount soldering (ensure mechanical strength).

3. Comparison with Similar Packages

4. Typical Device Models

5. PCB Design Recommendations

1. Pad Size (Surface-mount):

   • Thermal Pad: 5×5mm (minimum 3×3mm).

   • Lead Pad: 1.5×1.5mm (spacing 2.54mm).

2. Thermal Optimization:

   • Use 2oz copper thickness + multiple vias to enhance heat dissipation.

   • For high-power applications, a small external heatsink (e.g., AAVID 573300) can be attached.

3. Soldering Process:

   • Peak reflow soldering temperature should be ≤260°C (lead-free process).

6. 3D Models and Dimensional Diagrams

• STEP Files: Available for download from manufacturers’ websites (e.g., TI, ON Semi).

• Pin Definition (viewed from the front, left to right):

|-----------10mm-----------|
| +-----------+             |
| | TO-251    |             |
| | (IPAK)    |             |
| +-----+-----+             |
| | | | |                   |
| G D/C S/E | (Lead spacing 2.54mm)
|_________________________|

7. Selection and Replacement Recommendations

• Applicable Scenarios:

  • Space-constrained medium power applications (e.g., appliance control boards, LED drivers).

  • Flexible designs requiring both through-hole and surface-mount compatibility.

• Replacement Options:

  • For higher power: TO-220 (through-hole) or TO-252 (surface-mount).

  • For smaller size: SOT-223 (surface-mount, lower power).

Summary

The core advantage of TO-251 (IPAK) is its compact size and compatibility with both through-hole and surface-mount methods, making it ideal for:

• 5A~20A medium to low power scenarios

• Space-sensitive designs (e.g., consumer electronics)

• **Low-cost replacement for TO-220 through-hole solutions

Caution:

• Ensure mechanical strength when surface-mounting.

• For high-current applications, optimize PCB thermal design.

TO-3P Package Detailed Parameters

TO-3P is a high-power metal package mainly used for high-voltage and high-current power devices (such as transistors, IGBTs, and voltage regulators). Its heat dissipation capacity is superior to TO-220 and TO-247, and it is commonly used in industrial power supplies, motor drives, and similar applications.

1. TO-3P Standard Dimensions (unit: mm)

2. Mechanical Structure Features

• Metal Shell Design:

  • Full metal package (usually copper or aluminum) provides excellent heat dissipation, and it can be directly mounted on a heatsink.

  • The shell is electrically connected to the collector (C), requiring insulation (e.g., mica sheet + thermal grease).

• Pin Configuration:

  • 3 Pins: Base (B), Collector (C), Emitter (E) or corresponding MOSFET/IGBT polarity.

  • Some models feature 2 Pins (e.g., power diodes).

• Mounting Method:

  • Mounted on a heatsink using an M4 screw (torque recommended 0.6~0.8Nm).

3. Comparison with Similar Packages

4. Typical Device Models

5. Heat Dissipation and Mounting Design Recommendations

1. Heat Dissipation Requirements:

   • Thermal resistance RθJA: Around 15~20°C/W without a heatsink; requires forced air or water cooling.

   • Recommended heatsink: ≥100×100mm aluminum finned heatsink (e.g., AAVID 0938 series).

2. Insulation Treatment:

   • Use mica or ceramic insulator sheets + thermal grease (thermal conductivity ≥5W/mK).

3. PCB Layout:

   • For high-voltage applications, ensure pin spacing ≥8mm (to prevent creepage).

6. 3D Models and Dimensional Diagrams

• STEP/DXF Files: Available for download from manufacturers’ websites (e.g., ON Semi, Vishay).

• Dimensional Diagram:

|-----------26mm-----------|
| +-----------------+       |
| | TO-3P           |       |
| | (Metal Shell)   |       |
| +--------+--------+       |
| | | | |                  |
| B C E | (Lead spacing 5.45mm)
|__________________________|

7. Selection and Replacement Recommendations

• Applicable Scenarios:

  • High current linear amplification (e.g., audio power amplifiers).

  • High-voltage switching circuits (industrial power supplies).

• Replacement Options:

  • Modern designs may opt for TO-264 or IGBT modules (e.g., Infineon FF600R12ME4).

Summary

TO-3P is a classic high-power metal package, with advantages including:

• Excellent heat dissipation (metal shell directly conducts heat).

• High voltage/current capability (up to 300A+).

• High mechanical strength (vibration-resistant).

Cautions:

• The metal shell is live and requires insulation treatment.

• Gradually being replaced by newer packages like TO-264, but still used for retrofitting older devices.