PCB Temperature Rise Calculator
Understanding PCB Thermal Design
1. Basic Principles
PCB thermal management involves copper area, thermal vias, and layer stacking to effectively dissipate heat from components.
ΔT = P × θja
θja = 1 / (h × A)
Rvia = L / (k × A × N)
Rcu = L / (k × W × t)
Common Questions
What is PCB Temperature?
PCB temperature refers to the operating temperature of printed circuit boards during operation and manufacturing processes. It affects reliability, performance and lifetime of electronic components.
PCB Temperature Limits
| Parameter | Temperature Range | Notes |
|---|---|---|
| Operating Temperature | -40°C to +85°C | Commercial grade |
| Storage Temperature | -55°C to +125°C | Non-operating |
| Soldering Temperature | 230-260°C | Lead-free process |
Best Temperature for Soldering PCB
Recommended soldering temperatures:
- Lead-based solder: 315-330°C
- Lead-free solder: 350-370°C
- Reflow peak: 235-250°C
- Hand soldering: 300-350°C
- Maximum exposure: 10-30 seconds
2. Key Parameters
Important PCB thermal parameters:
- Copper Area
- Copper Thickness
- Thermal Vias
- Layer Count
- Board Material
- Component Power
3. Design Factors
Consider these factors in PCB thermal design:
- Component Location
- Copper Distribution
- Via Pattern
- Layer Stack-up
- Air Flow
- Space Constraints
4. Optimization Tips
Tips for optimizing PCB thermal performance:
- Maximize Copper Area
- Use Thermal Vias
- Consider Inner Layers
- Optimize Component Placement
- Add Thermal Relief
- Consider Heat Spreading
PCB Storage and Handling
PCB Storage Temperature and Humidity
| Condition | Requirement | Duration |
|---|---|---|
| Short-term Storage | 20-30°C, 30-60% RH | <6 months |
| Long-term Storage | 5-21°C, 20-50% RH | >6 months |
| Baking Required | 125°C | 4-8 hours |
PCB Temperature Testing
Methods for measuring PCB temperature:
- Thermal imaging camera
- Embedded temperature sensors
- Thermocouple measurements
- Infrared thermometer
- Temperature indicator labels
PCB Temperature Rise
Factors affecting PCB temperature rise:
- Component power dissipation
- Copper thickness and area
- Thermal via density
- Board material (FR4 vs high Tg)
- Ambient conditions
PCB Temperature Ratings
| Material | Tg (°C) | Applications |
|---|---|---|
| FR4 Standard | 130-140 | General use |
| High Tg FR4 | 170-180 | Lead-free |
| Polyimide | 260+ | High temp |
Troubleshooting Guide
Common Temperature Issues
| Problem | Possible Causes | Solutions |
|---|---|---|
| PCB Delamination | • Excessive temperature • Poor material quality • Moisture exposure | • Control process temperature • Use high Tg material • Proper storage |
| Hot Spots | • Poor thermal design • Component clustering • Insufficient copper | • Improve layout • Add thermal vias • Increase copper area |
| Solder Issues | • Wrong temperature • Poor profile • Contamination | • Adjust temperature • Optimize profile • Clean surfaces |
Temperature Monitoring
Best practices for PCB temperature monitoring:
- Use multiple measurement points
- Monitor critical components
- Record temperature profiles
- Set temperature alerts
- Regular thermal imaging
PCB Temperature Rise Calculator
How to calculate PCB temperature rise:
- Determine power dissipation
- Calculate thermal resistance
- Consider copper area effect
- Account for thermal vias
- Add safety margin
Industry Standards
PCB Temperature Standards
| Standard | Description | Requirements |
|---|---|---|
| IPC-2221 | Generic PCB Design | • Temperature ratings • Thermal management • Design guidelines |
| IPC-4101 | Base Materials | • Tg specifications • Thermal properties • Material grades |
| J-STD-020 | Moisture Sensitivity | • Reflow profiles • Storage conditions • Baking requirements |
Temperature Testing Standards
- IPC-TM-650 2.4.24: Glass Transition Temperature
- IPC-TM-650 2.4.25: Time to Delamination
- IPC-9701: Temperature Cycling
- MIL-STD-883: Thermal Testing
- JEDEC JESD22-A104: Temperature Cycling
Compliance Requirements
- RoHS: Lead-free soldering temperatures
- UL 796: Operating temperature ratings
- IEC 61189: Test methods for materials
- ISO 9455-17: Thermal properties testing
- ASTM D3850: Thermal analysis methods
Documentation Requirements
Required temperature-related documentation:
- Material datasheets with Tg values
- Thermal test reports
- Temperature profile records
- Storage condition logs
- Thermal simulation results
Quick Reference
Copper Properties
1 oz: 35 µm
2 oz: 70 µm
3 oz: 105 µm
4 oz: 140 µm
Design Tips
- • Use 2 oz copper
- • Add thermal vias
- • Connect layers
- • Avoid thermal islands
- • Consider airflow
Common Values
Via Properties
Drill: 0.3-0.4 mm
Plating: 25 µm
Spacing: 0.8-1.0 mm
Pattern: Grid/Array
Temperature Rise
Low: <10°C
Medium: 10-30°C
High: 30-50°C
Critical: >50°C