Enhancing Thermal Performance of CSP Integrated Circuits


Reading time ( words)

In the portable electronics market, power management integrated circuits (PMICs) are increasingly found being packaged into ball grid array (BGA) and chip scale packages (CSP) for their lower material costs, improved electrical performance (no bond wire impedances), and smaller form factors. These advantages do not come without compromise: The silicon die of CSPs are no longer in direct contact with large heat-spreading thermal paddles (E-PADs) used for electrical and thermal conduction.

This is the primary performance trade-off; because the IC substrate is not in contact with an E-PAD there is no high-conductivity direct thermal connection from the substrate to the heat-spreading copper planes on the PCB. This article will discuss PCB level methods that will lower the operating temperature of CSP devices by examining methods to transfer heat from the source and transport it to the ambient environment by lowering thermal resistance of the CSP IC. There are usually multiple ways to enhance the performance while simultaneously lowering the operating temperature that can be incorporated into new boards or revisions of existing boards.

In order to meet size and weight requirements, constraints of portable electronic designs often force PCB designers to reduce the size of components and PCB real estate area. To meet these demands, the use of CSP packages to shrink the PCB area needed is a common change in designs. As a result of the reduction of total PCB area, the available options to move heat and route high-power PCB traces is also reduced. Furthermore, the thermal performance cannot be matched when a QFN is compared to an equivalent CSP package; therefore, it is imperative that the PCB is designed to optimize heat transfer from the CSP to the PCB, which in turn dissipates it into the atmosphere. The parameter measuring the heat conductivity is the junction-to-ambient thermal resistance specification, Theta-JA (ӨJA (˚C/W)).  

To read this entire article, which appeared in the January issue of The PCB Design Magazine, click here.

Share




Suggested Items

Pulsonix Collision Avoidance to Bring Mechanical Capabilities Into ECAD

05/19/2022 | I-Connect007 Editorial Team
The I-Connect Editorial Team recently spoke with Bob Williams, managing director of Pulsonix. He discussed some of the new features in the upcoming version of the Pulsonix PCB design tool, Version 12, including collision avoidance and other 3D options that allow certain MCAD functions within the ECAD environment.

A Textbook Look: Signal Integrity and Impedance

05/18/2022 | Pete Starkey, I-Connect007
Believing that I knew a bit about signal integrity and controlled impedance, I was pleased to take the opportunity to connect with an educational webinar that I hoped would extend my knowledge. In the event I was surprised at how little I actually knew, and the webinar was an excellent learning opportunity. The webinar was introduced and expertly moderated by Anna Brockman of Phoenix Contact in Germany.

Designing in a Vacuum Q&A: Carl Schattke

05/11/2022 | Andy Shaughnessy, Design007 Magazine
Not long ago, I caught up with Carl Schattke, CEO of PCB Product Development LLC and a longtime PCB designer, for his thoughts on “designing in a vacuum.” As Carl points out, if you follow PCB design best practices, knowing the identity of your fabricator is not a “must-have.” He also offers some communication tips for discovering the information you do need, including one old-fashioned technique—just asking for it.



Copyright © 2022 I-Connect007. All rights reserved.