Advanced Thermal Solutions, Inc. (ATS) is hosting a series of monthly, online webinars covering different aspects of the thermal management of electronics. This month’s webinar will be held on Thursday, Feb. 21 from 2-3 p.m. ET and will cover heat sink design and selection. Learn more and register at https://qats.com/Training/Webinars.
Marketing Communications Specialist Josh Perry sat down with Product Engineering Manager Greg Wong to discuss the process that Advanced Thermal Solutions, Inc. (ATS) engineers go through to create a heat sink and find a thermal solution for customers.
Watch the full conversation in the video below and scroll down to read the transcript of the interview.
JP: Greg, thanks again for joining us here in marketing to explain what it is that goes into designing a heat sink for a customer. So, how does that process begin?
GW: We usually start with a few basic parameters; we call them boundary conditions. So, we start with a few boundary conditions, basics like how much airflow we have, how much space constraint we have around a heat sink, and how much power we’re dissipating, as well as the ambient temperature of the air coming into the heat sink.
So, those are the real basic parts that we need to start out with and sometimes the customer has that information and they give it to us, and usually we double-check too, and then other times the customer has parts of the information, like they know what fan they want to use and they know what kind of chassis they’re putting it in and we take that information and we come up with some rough calculations so we can arrive at those things like air flow and stuff like that.
JP: When you get the data from the customer, how do you determine what the problem is, so that way you can move forward?
GW: We usually start out with an analytical analysis. So, we put pen to paper and we start out with basic principles of heat transfer and thermal resistance and stuff like that so we can understand if what we’re trying to achieve is even feasible and we can come up with some basic parameters just using that analytical analysis.
Like we can calculate what kind of heat sink thermal resistance we need or we can calculate how much air flow we need or, if we have several components in a row, we can calculate what the rough air temperature rise is going to be along that chain of parts. So, there’s a lot we can do when we get the basic information from the customer just on pen and paper.
JP: What’s the next step beyond analytical?
GW: Well, we can do some lab testing or a lot of times we also use CFD simulations and, if our customer has a model they can supply us, we can plug that into the CFD simulations and we can come up with an initial heat sink design and we can put that into the simulations as well and then we set those up and run them.
The great thing, having done these analytical analyses beforehand, we know what to expect from CFD simulations. So that way, if the simulations don’t run quite right, we already have an understanding of the problem, we know what to expect, because CFD is not 100 percent reliable.
I mean, you can go and plug all this stuff in there but you really have to understand the problem to know if the CFD is giving you a good result. So, oftentimes that’s the next stage of the process and from there we can actually produce low-volume prototypes right here in Norwood (Mass.), in our factory. We have CNC machines and manual milling machines, lathes, all that kind of stuff, and we can produce the prototypes and test them out here in our labs.
JP: How much of a benefit is it to be able to create a prototype and to be able to turn one around quickly like that?
GW: Oh, it’s great. I mean, if we had to wait to get parts from China it will take weeks to get. We can turn them around here in a few days and the great thing about that is we can test them in our labs and, you know, when it comes to getting results nothing beats the testing.
I mean, you can do analytical analysis, you can do CFD simulations, but when you actually test the part in a situation that is similar to what the actual thing is going to be that’s where the real meat comes down.
ATS engineers take customer data and using analytical modeling and CFD simulations can design the right cooling solution to meet the customer’s specific thermal needs. (Advanced Thermal Solutions, Inc.)
JP: So, we test the prototypes before sending them out to the customer? We do the testing here or do we send it to them first?
GW: It all depends on what the customer requires. Sometimes the customer has a chassis that we really can’t simulate in our labs, so we might send the prototype heat sinks to the customer and the customer will actually put them into their system to test them out.
Other times, a customer might have a concept and they don’t actually have a product yet, so we’ll mock something up in our labs and we’ll test it and it all just depends what the customer needs and also how complex the problem is.
If it’s a simple heat sink and pretty simple airflow, we might not need to test that because we understand that pretty well, but the more complex the chassis is and how the airflow bends and stuff like that, the greater benefits we get out of lab testing.
JP: Well, I appreciate it Greg. Thank you for taking us through the process of making a heat sink and solving thermal problems for our customers.
GW: Sure Josh. We love seeing new thermal challenges and coming up with ways of keeping stuff cool.
For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit www.qats.com or contact ATS at 781.769.2800 or firstname.lastname@example.org.
ATS engineers worked on a comparison of a copper heat sink with an aluminum heat sink that had embedded heat pipes running underneath the components. Analysis showed that the aluminum heat sink nearly matched the thermal performance of the copper and was within the margin required by the client. (Advanced Thermal Solutions, Inc.)
Using analytical modeling and CFD simulations, the ATS engineers determined that switching to an aluminum heat sink with heat pipes that run underneath the components yielded case temperatures that were greater than 4.35%, on average, of those achieved with the copper heat sink. The largest difference between the two heat sinks was 9.2°C, over a single component.
• Challenge: The client wanted a redesign of a custom copper heat sink to an equivalent or better aluminum heat sink with embedded copper heat pipes.
• Chips/Components: Two Inphi (formerly ClariPhy) Lightspeed-II CL20010 DSPs at 96 watts and two Xilinx 100G Gearboxes at 40 watts each.
• Analysis: Analytical modeling and CFD simulations determined the junction temperatures between the four components when covered by a copper heat sink (Design 1), by an aluminum heat sink with heat pipes that stop in front of the components (Design 2), and by an aluminum heat sink with heat pipes that run underneath the components (Design 3). The analysis demonstrated the difference between the heat sink designs in relation to thermal performance.
• Test Data: CFD analysis showed an average component case temperature of 158.8°C with the original copper heat sink design, 158.3°C with Design 2, and 152°C with Design 3. The average difference in temperature between Design 1 and Design 2 was 0.5°C and the average temperature difference between Design 1 and Design 3 was 6.8°C.
Here is a CFD simulation from the top of the aluminum heat sink with the air hidden, showing the temperature gradient through the heat sink. (Advanced Thermal Solutions, Inc.)
• Solution: The client was shown that aluminum heat sinks with heat pipes provided nearly the same thermal performance as the original copper heat sink design and at much lower cost and weight. The component junction temperature differences between Design 1 and Design 3 were well within the margin set by the client.
o The simulated air velocity is lower and the airflow cross section is larger than in the actual application, meaning absolute temperatures are higher than the customer has seen in their testing.
• Net Result: Despite using conservative thermal conductivity calculations, aluminum heat sinks with heat pipes were shown to be a more cost-effective solution for achieving the client’s thermal needs than copper.
We’ve just released our new line of standard board level heat sinks. These stamped heat sinks are ideal for PCB application, especially where TO-220 packages are used. Available now through Digi-Key Electronics or at this link from ATS http://www.qats.com/eShop.aspx?produc…
ATS has released a Consulting Project Subscription Plan (CPSP) for engineering services. From our corporate headquarters in Norwood, Massachusetts,we offers comprehensive thermal management analysis and design services for the telecommunications, medical, military, defense, aerospace, automotive, and embedded computing industries. The new plan allows ATS engineers to become an extension of your team for a pre-determined amount of hours, providing expert thermal and mechanical engineering consultation, design, simulation, testing and validation.
Services include Design, Simulation, Testing, Analysis & Prototyping
The CPSP includes the use of ATS thermal lab facilities and covers all projects approved by an authorized representative of subscribed customers. ATS thermal management analysis and design services encompass both experimental and computational simulations using proprietary tools and computational fluid dynamics software packages such as FLOTHERM and CFdesign.
Thermal Testing & Analysis
The new subscription plan gives customers priority access to ATS engineering and manufacturing resources for all chip, board, enclosure, and system related projects. ATS studies the full packaging domain, including components, circuit boards (PCBs), shelves, chassis, and system packaging.
Consulting capabilities include:
– heat sink, board and fan characterization
– heat sink design and optimization
– PCB & fan tray design and optimization
– liquid cooling design
– prototyping of heat sinks and complete cooling systems
– wind tunnel testing of components, PCBs, chassis and enclosures
ATS offers rapid prototyping of machined parts and cooling systems from its US facilities. Sheet metal fabrication and cut heat sink prototypes are quickly provided from international partners.
Liquid Crystal Thermography
ATS believes that customers who wish to remain competitive should consider a design-to-suit opportunity solution first. Contrary to common perception, this proves to be less expensive to the customer in the long run, because of the ensuing gain in product efficiency and compatibility. Working side-by-side with customers worldwide, ATS engineers provide tailored solutions to thermal and mechanical packaging challenges on real projects with real schedules.