1. On the PCB board, copper is a strong conductor with a high melting point, but it’s essential to keep it cool.
2. You need to size the trace width appropriately to maintain the temperature within a specific range.
3. Here, you must consider the current flowing through a given trace.
4. When dealing with power rails, high-voltage components, and other heat-sensitive parts of the board, the trace width should be calculated based on the current and desired impedance.
5. Most tables do not account for controlled impedance routing.
6. While tables are useful, they may not provide accurate temperature rise predictions; thus, a calculator is often required.
7. Alternatively, use the IPC2152 nomogram to ensure that the current-temperature relationship remains within the operating range for controlled impedance traces.
1. A common challenge in PCB design and routing is determining the optimal trace widths to keep device temperatures within a specified range for a given current, and vice versa.
2. Although copper has a high melting point and can endure elevated temperatures, ideally, you should keep the temperature rise of the board within 10°C.
3. Allowing PCB traces to reach very high temperatures increases the ambient temperature around the component, thereby placing a greater burden on active cooling measures.
4. The IPC-2152 standard is essential for sizing traces and vias, providing formulas to calculate current limits for specific temperature rises.
5. However, these formulas do not account for controlled impedance routing.
6. Using a PCB trace width versus current table is a good starting point for determining trace width or cross-sectional area.
7. This helps establish an upper limit on the allowable current, which can then be used to size traces for controlled impedance routing.
8. Electrical properties of the substrate change at high temperatures, and prolonged operation at high temperatures can discolor and weaken substrates.
9. This is why designers often size traces to keep temperature rise within 10°C.
10. Another reason is to accommodate a wide range of ambient temperatures rather than a specific operating temperature.
11. The trace width versus current table below shows trace widths and corresponding current values that limit temperature rise to 10°C for 1 oz/sq. ft. copper weight.
12. This provides guidance on how to size PCB traces effectively.
13. Trace thickness depends on the copper weight; we include the standard 1 oz/sq. ft. value, but high-current boards often need heavier copper for higher temperature rises.
14. If controlled impedance routing is required, verify that the calculated trace size meets specified constraints.
15. The data provided is for FR4 substrates, but other applications may require aluminum core PCBs, ceramic substrates, or high-speed laminates.
16. Using substrates with higher thermal conductivity will enhance trace cooling by removing heat from the traces.
17. For a first-order approximation, the temperature rise scales with the ratio of the thermal conductivity of the desired substrate to that of FR4.
18. If different copper weights are used, verify trace size for temperature rise and current, then use the IPC-2152 nomogram for accurate sizing.
19. This is an effective method for sizing conductors for specific current and temperature rise.
20. If you select a trace width, you can determine the current that will result in a specific temperature rise.
21. The red arrows illustrate how to determine the required trace width, copper weight (i.e., trace cross-sectional area), and current for a specific temperature rise.
22. For instance, select a conductor width (140 mils), then trace horizontally to the desired copper weight (1 oz/sq. ft.).
23. From there, trace vertically to the desired temperature rise (10°C), and then trace back to the y-axis to find the corresponding current limit (2.75A).
24. The orange arrow illustrates the reverse process: start with the desired current (1A) and trace horizontally to the desired temperature rise (30°C).
25. Next, trace vertically to determine the trace size.
26. If specifying 0.5 oz/sq. ft. copper weight, trace back horizontally to the y-axis to find the conductor width of approximately 40 mils.
27. For 1 oz/sq. ft. copper weight, the required trace width would be 20 mils on the PCB board.
2. You need to size the trace width appropriately to maintain the temperature within a specific range.
3. Here, you must consider the current flowing through a given trace.
4. When dealing with power rails, high-voltage components, and other heat-sensitive parts of the board, the trace width should be calculated based on the current and desired impedance.
5. Most tables do not account for controlled impedance routing.
6. While tables are useful, they may not provide accurate temperature rise predictions; thus, a calculator is often required.
7. Alternatively, use the IPC2152 nomogram to ensure that the current-temperature relationship remains within the operating range for controlled impedance traces.
1. A common challenge in PCB design and routing is determining the optimal trace widths to keep device temperatures within a specified range for a given current, and vice versa.
2. Although copper has a high melting point and can endure elevated temperatures, ideally, you should keep the temperature rise of the board within 10°C.
3. Allowing PCB traces to reach very high temperatures increases the ambient temperature around the component, thereby placing a greater burden on active cooling measures.
4. The IPC-2152 standard is essential for sizing traces and vias, providing formulas to calculate current limits for specific temperature rises.
5. However, these formulas do not account for controlled impedance routing.
6. Using a PCB trace width versus current table is a good starting point for determining trace width or cross-sectional area.
7. This helps establish an upper limit on the allowable current, which can then be used to size traces for controlled impedance routing.
8. Electrical properties of the substrate change at high temperatures, and prolonged operation at high temperatures can discolor and weaken substrates.
9. This is why designers often size traces to keep temperature rise within 10°C.
10. Another reason is to accommodate a wide range of ambient temperatures rather than a specific operating temperature.
11. The trace width versus current table below shows trace widths and corresponding current values that limit temperature rise to 10°C for 1 oz/sq. ft. copper weight.
12. This provides guidance on how to size PCB traces effectively.
13. Trace thickness depends on the copper weight; we include the standard 1 oz/sq. ft. value, but high-current boards often need heavier copper for higher temperature rises.
14. If controlled impedance routing is required, verify that the calculated trace size meets specified constraints.
15. The data provided is for FR4 substrates, but other applications may require aluminum core PCBs, ceramic substrates, or high-speed laminates.
16. Using substrates with higher thermal conductivity will enhance trace cooling by removing heat from the traces.
17. For a first-order approximation, the temperature rise scales with the ratio of the thermal conductivity of the desired substrate to that of FR4.
18. If different copper weights are used, verify trace size for temperature rise and current, then use the IPC-2152 nomogram for accurate sizing.
19. This is an effective method for sizing conductors for specific current and temperature rise.
20. If you select a trace width, you can determine the current that will result in a specific temperature rise.
21. The red arrows illustrate how to determine the required trace width, copper weight (i.e., trace cross-sectional area), and current for a specific temperature rise.
22. For instance, select a conductor width (140 mils), then trace horizontally to the desired copper weight (1 oz/sq. ft.).
23. From there, trace vertically to the desired temperature rise (10°C), and then trace back to the y-axis to find the corresponding current limit (2.75A).
24. The orange arrow illustrates the reverse process: start with the desired current (1A) and trace horizontally to the desired temperature rise (30°C).
25. Next, trace vertically to determine the trace size.
26. If specifying 0.5 oz/sq. ft. copper weight, trace back horizontally to the y-axis to find the conductor width of approximately 40 mils.
27. For 1 oz/sq. ft. copper weight, the required trace width would be 20 mils on the PCB board.
