The biggest foe of all electronic gadgets is heat. It develops slowly and when it becomes an obvious issue, may be irreparable. Parts wear out before they appear to be meant to, products become less efficient and less effective, and products break prematurely.

That’s why proper heat pipe design is given much more consideration than is often given. It’s more than a spec sheet item. Often the distinction is between a product that works well in actual use for years and one that is prone to failures under the actual conditions of its use. This is the principle that can be found in the development of thermal solutions that have been worked out and perfected over the last several years to prevent business failures that can be avoided by better planning by companies such as PT Heatsink. This is a very important piece of engineering, and here’s why.

How Heat Pipes Actually Work

At first sight, a heat pipe appears to be a bare metal pipe. But, something smart is going on inside.

A small amount of fluid is placed in a sealed chamber that is under a vacuum. If a heat is absorbed at one end of the pipe, then that fluid will evaporate. The vapour passes to the cooler end and cools down and condenses into a liquid. It then returns to the hot end, typically via a wick design and the cycle repeats.

This allows for the transportation of much more heat than can be transported by solid metal conduction. This is the reason why heat pipes can be found in such a wide variety of applications including laptops, LED displays, telecom equipment, and many other applications that are required to deal with severe thermal loads in confined areas.

Why the Design Details Actually Matter

Not All Heat Pipes Perform the Same Way

Two heat pipes can be almost the same, and yet have very different performance. The amount of heat that a pipe can transport and the rate at which it can transport it depends on the pipe diameter, the structure of the wicks, the type of fluid used and the orientation of the pipe.

The pipe may function well on testing but not in the final position when installed in a device where the fluid returns to the pipe and the device is not oriented on its back. That is why experienced thermal engineers test the designs, with the actual conditions of operation, not necessarily in ideal conditions in the lab.

Integration With the Rest of the Cooling System

Heat pipe is typically not used as a standalone solution. Typically it is attached to a base plate or heatsink assembly, which helps to distribute and dissipate heat. A newer combination is a skived fin heatsink, which has fins that are cut from a solid block of metal, instead of being bonded or extruded.

This manufacturing process allows for closer and thinner fins increasing surface area with little increase in size. When used together with an optimized heat pipe, the system can be very efficient at enhancing the heat removal and air flow efficiency, particularly in space constrained applications like small-size heaters.

Material Choices Affect Performance and Cost

The materials used frequently for heat pipes are copper, which has good thermal conductivity, but is heavier and more expensive than aluminum. Several designs integrate both materials to achieve a combination of performance, weight and cost, depending on the requirement of the application.

Manufacturing Precision Can’t Be an Afterthought

Loose manufacturing tolerances can detract from a great design. If the bond is less than ideal between the pipe and heatsink structure, there will be thermal resistance and less efficiency. It’s not just about the concept, but the precision as well.

Common Mistakes That Reduce Efficiency

• Choosing pipe diameter based on cost rather than heat load requirements
• Not following the recommended orientation when installing in the field.
• Inadequate thermal bond between the pipe and heatsink base
• Looking at how the airflow could design around the fin structure.
• Failing to do real world testing instead of only lab testing

Any of these errors in the early stages will mean more expensive re-designs later.

Why This Matters for Your Business

When your product is hot, it tends to bite you in the ass for cutting corners on thermal design, in the form of failure, disgruntled customers, or even costly rework. Whether you need to work with a manufacturer who understands the engineering and manufacturing aspects of a thermal solution, or you’re considering skived fin solutions, having a thermal solution expert who can work with you in these areas can save you time and money in the long run.

Conclusion

This efficient heat dissipation isn’t something that just happens. From the structure of the wick to the geometry of the fins, it’s a careful engineering decision that influences the overall performance and product life.

When you need to know that you have reliable thermal performance for your next project, it may be worth finding out what PT Heatsink can do for you. Contact them today, and they’ll provide you with a solution to cool your product to fit its true needs.

Frequently Asked Questions

1) What is the difference between a heat pipe and a regular heatsink, and how can I determine if my product requires a heat pipe or a regular heatsink? Heat pipes are typically a better option than the standard finned heat exchanger when there is not enough space to create a fan-cooled heat exchanger, or a fan-cooled heat exchanger would not keep the device temperature within a safe range.

2)What is the difference between a “skived fin” heatsink and a standard heatsink? The fins are cut directly from a solid metal block versus bonding or extruding fins, which allows for thinner and more compact fins to be cut to allow for more surface area in a smaller footprint.

3) Is the orientation of heat pipes really that important to affect performance so significantly? Yes. Fluid return may be dependent upon a wick structure and gravity, so orientation will affect fluid return and overall thermal efficiency.