An online heat sink calculator is an essential tool for engineers designing thermal management systems. It evaluates the thermal performance of heat sinks by comparing a solid metal base to one that incorporates a vapor chamber base. By calculating thermal resistance and temperature rise (delta-T), the calculator helps determine whether a heat sink design operates within the specified thermal budget.
Components of a Thermal Network
The thermal resistance network for a heat sink includes key components (R), as shown in the diagram, which collectively determine the temperature rise (delta-T).
Heat Sink Delta-T Thermal Resistance Network
Using the Heat Sink Calculator
Engineers input the following details to compute heat sink performance:
Heat Source Information
- Power (TDP): Total dissipated power from the IC, found in the spec sheet or provided by the ASIC designer.
- Size (L × W): Used to calculate power density.
- Location: Placement on the heat sink (center, edge, or corner) affects the distance heat needs to travel.
Heat Sink Base Information
- Base Size: An initial estimate derived from the required volume.
- Material: Choose aluminum, copper, or a vapor chamber base for evaluation.
- Thickness: Combined with fin height to determine the total heat sink height.
Fin Information
- Height: Typically ranges between 10–35mm.
- Thickness and Gap: Zipper fins range from 0.2–0.6mm, with gaps at least twice the fin thickness.
- Material: Aluminum or copper options are available.
- Airflow (CFM): Increased airflow through the fin stack reduces required heat sink size and improves heat sink thermal resistance.
Heat Source Information
- Heat source power (TDP) – check the IC spec sheet or ask your ASIC designer.
- Heat source size (LxW) – used to calculate IC power density.
- Heat source location on the heat sink (center, edge or corner) – indicates how far heat needs to be moved.
Heat Sink Base Information
- Base size – an estimate of the total volume can be found using this online heat sink size calculator from which specific dimensions can initially be assigned.
- Base material – select between an aluminum or copper base, which is subsequently evaluated against a vapor chamber option.
- Base thickness – this figure plus fin height = total heat sink height.
Fin Information
- Fin height – varies but typically in the 10-35mm range.
- Fin thickness & gap – zipper fins range from 0.2-0.6mm while gap should be at least 2X thickness.
- Fin material – aluminum or copper.
- Airflow (CFM) – required heat sink size shrinks substantially as more airflow is allowed to pass through the fin stack.
Sample Heat Sink Calculator Output
Here are some calculator results from a sample heat sink application.
Add the result of the line items in red (above) to the base detla-T (below) which is shown for both a solid metal and vapor chamber base.
Once the baseline is established, engineers can begin optimization to refine dimensions, materials, or airflow parameters for enhanced heat sink performance.
By leveraging a heat sink calculator, engineers can evaluate and optimize heat sink thermal resistance and overall performance. This approach ensures that thermal solutions meet stringent requirements while staying within budget, paving the way for efficient, cost-effective designs.
