Category Archives: Manufacturing

High Fin Density Heat Sink Manufacturing, Is Zipper Fin Best?

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**

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

Zipper Fin Heat Sinks Answer the Need for Reasonable Cost and Good Performance

ATS’s design services and manufacturing have delivered zipper fin (or stacked fin) heat sinks, in both aluminum and copper, or a combination of both materials, through our design services for the past few years. Our work has included zipper fin heat sinks with copper bases, embedded heat pipes and as standalone heat sinks. In some cases, our zipper fin heat sinks have been attached to semiconductors using either our maxiGRIP(tm) or superGRIP(tm) heat sink attachment technology, with phase change thermal interface material.

Zipper Fin Heat Sink ATS

Zipper fin heat sinks are manufactured using a single sheet of metal, most often copper or aluminum. They are manufactured in such a way that the fins interlock creating high fin density at a reasonable manufacturing cost. The unique manufacturing of a zipper fin heat sink can allow for unique, asymmetric and or radial fin geometries with the option to accommodate embedded heat pipes.  Zipper fin manufacturing also allows for heat sinks to be formed into a duct so that it creates a ducted flow for increased thermal conductivity.

ducted aluminum heat sink with zipper fin
[ATS Zipper Fin Heat Sink, from aluminum, with integrated copper base plate and the zipper finned heat sink including a duct in the design for ducted air flow through the heat sink]

Zipper fin heat sinks can be a less expensive alternative to skived heat sinks or folded fin heat sinks. Their thermal performance is similar but with a lower manufacturing cost.

zipper fin heat sinks with heat pipe embedded
[ATS Zipper Fin Heat Sink made with aluminum zipper fins,  embedded heat pipes and copper plate]

We have just published an interview with one of our engineers on our zipper fin heat sinks; it lasts about 8 minutes and talks through what ATS offers, and the differences between the various high fin density heat sink manufacturing types, so see it, or read the transcript, just click to this article on our blog:  High Fin Density Heat Sink Manufacturing, Is Zipper Fin Best?

If you have questions on our Zipper Fin or other high fin density heat sinks, please email us at or call us at 781-949-2521.

ATS Expands Its US-based Manufacturing Facilities

Advanced Thermal Solutions, Inc. has expanded its Massachusetts manufacturing facilities. This was necessary due to an increase in industrial orders and associated production requirements. The needs for metal and plastic parts and finished products have been growing as markets retool and expand, and buyers continually insist on higher quality, faster deliveries and larger volumes.

ATS expanded manufacturing services can provide contract manufacturing services on a fast, highest quality level. The Norwood facility will meet the needs of most global customers, from rapid prototyping and high volume manufacturing.

The enhanced facilities in Norwood, which is also the global headquarter for ATS, are fully equipped, environmentally responsible, and employ highly skilled staffers who work to extremely high professional standards. Multi-point inspections insure the highest quality manufactured products, from one-of-kind to multi-thousand part production orders.

ATS designs and builds for a wide range of industry requirements. Engineers and technicians manufacture for chassis-level integration, e.g. cooling hardware and other functionalities on network communication cabinets. The associates often design and fabricate stands, rack and display cabinets for retail and office environments.

Fabrication capabilities in metal and plastics include:
Metal and Plastic Extruding
Metal Stamping
CNC Machining
Metal Finishing
Sheet Metal Stamping and Plastic Forming
Plastic Welding

Besides its manufacturing facilities in Norwood, ATS operates factories in Futian, China, a thriving region of high tech manufacturing. The Futian facility is designed for making very high volumes of quality parts, as well as inventory and storage, and worldwide distribution services.

To learn more about ATS manufacturing capabilities, please visit:

ATS Contract Manufacturing Services

A “best kept secret” about Advanced Thermal Solutions is our contract manufacturing services. That’s right, ATS does contract manufacturing on a very wide variety of materials in both our rapid prototyping facility in Norwood MA and in our high volume facility in China. ATS has been doing contract manufacturing on various materials for many years, but, up to now, we haven’t talked much about it.  The reason? Our customers. They were the ones who let us know we were doing an incredible job and urged us to let others know. So this week that is what we’ll be doing here at ATS’s electronics cooling blog.

Here’s a brief list of our capabilities:


– Aluminum
-Stainless Steel

Our Norwood MA facility does the rapid prototyping and low volume production, here is a list of our equipment:

Machining Center

-vertical mills 40 X 20
-vertical mill 36 X 16
-CNC vertical mill 28 x 16
-CNC horizontal mill with dual 16 X 16 rotary pallets
-Manual vertical knee mills 9 x 50
-Mill/drill 28-1/2 X 8-1/4
-Manual horizontal knee mill 14 X 62
-Manual horizontal bed mill 11-3/8 X 51-5/8
-Manual Lathe 7 X 40

Saws & Shears

– Foot shear 36 x 16 Ga.
-Power shear 52 X 12 Ga.
-Table saws 10
-Vertical bandsaw 16 x 39
-Horizontal bandsaw 12-3/4 X 12-3/4 with automatic feed
-Chop saw 10


What else we got?
We have lots of stuff to talk about, but, rather than discuss the parts and pieces of our rapid prototyping and high volume manufacturing, its’ better to talk about examples, and we’ll be doing some of that this week here on ATS’s blog. In addition, we’ll be highlighting a very important engineering article on how to manufacture cold plates.

Rapid Prototyping and High Volume Manufacturing Through ATS Manufacturing Division

ATS manufacturing services include high precision, high capacity capabilities in metal and plastics fabrication that includes:

Metal and Plastic Extruding
Metal Stamping
CNC Machining
Sheet Metal and Plastic Forming
Plastic Welding

Your project can be submitted on-line through our on-line quote tool!

You can learn more about ATS’s manufacturing services here Rapid Prototyping and High Volume Manufacturing Through ATS Manufacturing Division

You may also contact us at 781-769-2800, email: or visit