-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueMechatronics
Our expert contributors discuss the advent of mechatronics in PCB design, the challenges and opportunities this creates for circuit board designers, and the benefits—to the employee and the company—of becoming a mechatronics engineer.
Creating a Culture of Collaboration
PCB designers could learn quite a bit from NASA and the private companies that develop spacecraft: Every one of these vehicles is a testament to the value of collaboration among disparate stakeholders. Without a collaborative culture, the rocket might never get off the ground.
Breaking High-speed Material Constraints
Do you need specialty materials for your high-speed designs? Maybe not. Improvements in resins mean designers of high-speed boards can sometimes use traditional laminate systems. Learn more in this issue.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - design007 Magazine
PCB Cooling Strategies, Part 1
January 19, 2018 | Bin Zhou, EDADOCEstimated reading time: 7 minutes
![](https://iconnect007.com/application/files/5316/3125/0829/bin_zhou.jpg)
With the development of communication and IT industries and the ever-increasing demand for information analysis, many chip makers have racked their brains trying to provide customers with better technology, such as increased computing power and storage capacity of chips as well as diversifying their product offerings.
For example, Huawei unveiled the Kirin 970 processor and Apple introduced their A11 processor to entice potential customers. However, the heat generated by the chips during operation, especially during high-speed operation, causes the internal temperature of the mobile phone to rise rapidly. If the heat is not effectively dissipated, the internal parts of the mobile phone will fail due to overheating and the reliability will decline. This issue must be addressed properly, or you will see disastrous results similar to Samsung’s Galaxy S7 phones. The circuit board heat management is very important, not just for cell phones, but for other electronics as well.
Traditionally, electronic equipment was cooled through technical means, structural modes and design techniques to meet the requirements of reliability and service life. With the improvement of communication and IT products and the ever-increasing demand for portability, the power consumption of information equipment is on the rise while the volume tends to decrease. Device density is high, so high heat flux density cooling needs are becoming more urgent, and thermal design will face enormous challenges.
Each electronic product requires a specific thermal design methodology, from the early architecture design and device selection, through PCB design, final assembly and packaging. Each section has a corresponding heat management plan. This requires thermal design engineers to use their theoretical knowledge combined with practical experience to develop a reasonable thermal design.
PCB design has a direct impact on product performance and time to market. Devices on the PCB have their own temperature range, and any temperature outside of this range will greatly reduce the efficiency or failure of the device, resulting in damage. Therefore, heat dissipation is a key issue to consider in PCB design.
The PCB substrate is in direct contact with the components, so its cooling capacity directly affects the cooling of the entire system. We know that the heat of components is not conducted by the PCB itself, but by the surface of the components from the ambient air. So, the heat dissipation characteristics are dependent on the size of electronic products. Today, the miniaturization of product components and high-heat-generating assembly mean that we will need to alter our cooling methods. Heat dissipation on the surface will not be enough for conventional PCB designs.
At the same time, due to the use of QFP, FPGA, BGA and other highly integrated surface mount components, the heat generated by the components will be transmitted to the PCB. Therefore, the best way to increase the PCB’s cooling capacity is by conduction through the PCB itself. This means the choice of the PCB laminate is particularly important.
When selecting the PCB laminate, we must analyze the work environment. Plate heat dissipation capacity and thermal conductivity & heat resistance are closely linked. Thermal conductivity (K, °C) is the quantity of heat transmitted under stable heat transfer conditions.
Currently, there are five types of substrates used in the PCB market. They are: paper substrates, composite substrates, epoxy glass fiber cloth substrates, adhesive-coated copper foil (RCC), and special substrates in HDI.
- Paper substrates (FR-1, FR-2, FR-3) are the cheapest, but the soldering temperature is more stringent and is easily dampened and blistered. Any temperature of more than 260°C will cause it to turn yellow and it has poor heat characteristics. The thermal conductivity is much lower than 1.0W/mK.
- Composite substrates (CEM-1, CEM-3) are made of two kinds of materials: fiberglass cloth base and wood pulp paper base. It is an upgraded version of the paper substrate, with improved performance & mechanical machinability. However, it can only maintain 50 seconds at 260°C (Figure 4). Compared to the paper substrate alone, the thermal shock resistance does not greatly improve, and the thermal conductivity is less than 1.0W/mKK
Page 1 of 2
Suggested Items
Trouble in Your Tank: Materials for PWB Fabrication—Drillability and Metallization
07/16/2024 | Michael Carano -- Column: Trouble in Your TankLaminate materials are the building blocks on which printed circuit boards are manufactured. Circuit board designers rely on the critical electrical properties of the materials to design the interconnects, and with the drive toward IoT (internet of things), autonomous driving, and virtual and augmented reality, material properties take on a very high level of importance.
Beyond Prepreg: The Glassless ‘Revolution’
06/25/2024 | Marcy LaRont, PCB007 MagazineAs our industry rallies around the call to action for HDI and UHDI, we find unparalleled and myriad laminate options. This abundance is rivaled only by the question surrounding them: Can they measure up to the high technology packaging demands required in our near future? Unsurprisingly, recent developments in FR-4-esque materials for high-speed and high-density designs, as well as newer, glassless technology for replacing traditional glass-impregnated laminates and prepreg, are garnering much interest. I caught up with Alun Morgan, technology ambassador for Ventec International Group, to ask about the impending “glassless revolution” and how it’s poised to solve some of our manufacturing challenges.
Connect the Dots: Designing for Reality—Lamination and Materials
06/19/2024 | Matt Stevenson -- Column: Connect the DotsAs many of you have likely figured out, I am quite passionate about the subject of designing PCBs for the reality of manufacturing. I wrote a book about it and I participate in an I-Connect007 On the Line with… podcast series dedicated to the subject. This companion article will focus on multilayer lamination, keeping the bigger picture in mind: Realistic PCB designs should prioritize manufacturability and reliability of the PCB as well as meet the other design requirements. So, one must account for the production variables associated with individual manufacturing partners.
Day 2: A Full Day at the EIPC Summer Conference
06/19/2024 | Pete Starkey, I-Connect007Editor's note: This is the third and final report from the EIPC Summer Conference. It was a bright and early start to the second day of the 2024 EIPC Summer Conference at the European Space Centre, Noordwijk, The Netherlands, June 4-5. A short journey by bus from the hotel in Leiden and our security passes from the day before got us through the gate and to our seats in the Newton Room for Session 4, “Material Studies,” moderated by Martyn Gaudion.
Looking Into Space: EIPC Summer Conference, Part 2
06/17/2024 | Pete Starkey, I-Connect007“Innovative Development of PCB Technology and Design” was the theme of the second session of the 2024 EIPC Summer Conference, June 4-5, at the European Space Centre, Noordwijk, The Netherlands.