High fin density heat sinks can be fabricated via skiving, bonded fin, folded fin and zipper fin technologies. This video talks about the different types and about how Zipper Fin is a cost effective choice at high volume. The video interview is followed by a transcript of the interview.
**Hey Joe how’s it going? **
Great John, how are you?
**Good, thanks for stopping by marketing. **
Always a pleasure for engineering and marketing to come together.
**It really is and we love being in marketing because you can see some of the new products that are happening along with some of the new technology ATS is bringing forth and the way that we are dealing with our customers. I see you brought by some new technology here for us? **
Yes, new but not so new. Zipper fins is what we have here and we’ve been doing this for some time. They’ve been popular for years and years. They find a specific place in the market depending on their need and we have deployed them with great success.
**So, what exactly is a zipper fin? Can you explain the manufacturing process, the special technology or? **
Zipper fin is a multi-step assembly process, the zipper itself being made out of a sheet metal that is formed into a specific shape. That material is usually aluminum or copper and it has certain features on the fin itself (credit shakita). When placed together each fin is interlocking to its neighbor. When it’s all assembled it’s soldered to the base of the heat sink it’s a rigid body. It’s very reliable as far as fin density, shape, and its size.
**Now, why would a customer want us to build a zipper fin system? Is it cost or manufacturing quality or better heat transfer? **
Zipper fins compared to other designs that you have heard of called bonded fin. It’s similar to what we have but the tooling is a lot higher. One of the benefits with a zipper fin is you can actually manufacture a very high aspect ratio fin profile without high tooling cost. So, if you want really tall fins, really thin fins, and really tightly packed fins zipper fin may be the solution.
**That’s for more surface area right? **
Surface area exactly and also this type of zipper fin creates a duct. So when the zipper is covering the entire fin field, it creates a duct in the airflow which is much better for thermal performance.
**These are hollow in here and the reason for that is because its duct airflow, so it actually creates both a heat sinks and a duct in one piece. **
We use a lot this as well for active heat sinks with air movers, fans, or blowers. This heat sink here is in a system but its duct flow a zipper pack and also some customers even put an interface material on top of a zipper pack like this and conduct heat to the lid of a chassis.
**Do customers find it useful using this kind of device instead of other types of heat sinks in specific areas like military, or for example appliances? And is it really cost or volume driven? **
It’s mainly volume driven. Here at ATS we have a lot of zipper fins tooled up and ready to deploy on a heat sink base. So depending on the complexity on the base itself and the need for the surface area, and fin density based on the airflow these things have to align to be able to utilize a zipper fin. There are some things we cannot do via extruding, or skiving, or forging that we can do with a zipper fin.
For instance, either with copper or aluminum we can have a zipper fin that’s 0.2 millimeters thick. We cannot do that with a skiving process or an extruding process.
**You mentioned skiving, now would a customer choose this over skiving or would they make a decision based on premise not because they like one or the other? **
It really depends on what they need of the solution itself. Low volume skiving is comparable to zipper fin profile and most customers choose to skive first , but in high volume there is a breaking point where it makes sense to go to a zipper fin. With skiving we can skive aluminum and copper. A copper heat sink skived is very heavy, one of the benefits of zipper fin heat sink is we can have a have a copper base that gives us that heat spreading we can add an aluminum fin profile which reduces the weight significantly.
**There are other technologies that people use with thermal management such as ATS’s patented maxiGrip and superGRIP technologies that allow a perfect connection with the chip and allow the use of face changed material. Could those also be applied to a zipper fin? **
Yes, so as you see on the zipper fin heat sinks the fin neighbors each other all the way through. We can easily have maxiGrip or a superGRIP over the middle portion. We don’t always have to have the fin field throughout the entire width of the heat sink. We can split the fin back up if we need to allow specific features on the heat sink or clip on methods such as maxiGRIP, superGRIP, or z-clips. Push pins works as well, this is hard mounted onto the board. This heat sink is cooling about 12 total components on the bottom of this heat sink, this one utilizes the cooper for spreading and again it’s that weight factor we want to reduce so we use aluminum fins to which need to be nickel-plated when you solder.
**Now how about these two, I know these are from different applications than this one but they seem to all use zipper fin? **
The good thing about a zipper as well is if you were to stamp a fin for the zipper you can also during that stamping process allow for holes in the fins to allow crescent heat pipes. So here we have one tool for the fin itself to allow for the heat pipes and you can see this is the base of the heat sink that touches the component which is the evaporator section and the condenser section is actually the zippers away from the component then mounted to the board. But again, the zipper fin profile allows us to reduce weight significantly especially with the heat pipe application and it is one time tooling low cost production.
**What about this particular one? **
This is an all copper solution which is a stamped base, flat basic material, and a standard zipper fin copper profile that’s soldered on. So again it’s a multi-step process where you make a long zipper to break it off to your specific width, place it on the heat sink and wave solder. So again, when performance is critical these are performing some of the best numbers for heat sinks for that given envelope. Again, we can significantly increase the aspect ratio, reduce the fin thickness, and also fin density.
**And we’ve done a lot of these so it’s really a part of our design services and the we really help our customers get to the exact solution they need and not just some off the shelf solution but we give them the best cost and the best effective heat transfer.**
Exactly. We have many extrusion profiles in stock we also have many zipper fins in stock as well that we can pick and choose from depending on length, height, and orientation on a base to utilize for a solution. They need not all be square, we have some unique fins that are tooled up and we can also use the zipper fin to allow for a fin profile to be a circular (360 degrees) and we use that with a lot of active heat sinks and fans. So an axial type of zipper fins.
As you mentioned some of the industries; LEDs, embedded, military, and telecom and data-com.
**Consumer and appliances I would imagine maybe concerning the volume and the price? **
Exactly, once you do tool up if it’s something new then production will be a very low cost solution.
**If people want to know more about zipper fins they can contact us at www.qats.com.**
Absolutely! We’re here designing a lot of these and others if these are the right solution, we have the options.
To learn more, email us at ats-hq@qats.com.