The New Chapter: The Benefits of Continuing Education
It’s Only Common Sense: You’ve Got to Hustle
Asymmetric Hybrid Printed Circuit Board Design: Warpage Considerations
August 27, 2024 | Kaspar Tsang, Gause Hu, Jimmy Hsu, Aje Chang, Alan Sun, Brian Ho, Ryan Chang, and Thonas SuEstimated reading time: 2 minutes
Editor’s note: This excerpt is from a white paper presented at IPC APEX EXPO 2024, and is intended to give an overview and recommendation on the topic. To see a list of full papers and other conference proceedings, please click here.
Abstract
The printed circuit board (PCB) accounts for a significant portion of the PCBA’s (printed circuit board assembly) BOM (bill of material) cost. Designs with hybrid PCB stackup are adopted to reduce the cost of the PCB by using less expensive laminate materials in layers that do not have routings for high-speed signals (e.g., power and ground layers). The conventional hybrid PCB stackup design is symmetrical in the middle1. This engineering technique has been employed in the data center industry for quite some time. To extend the idea and optimize the purpose of hybrid PCB stackup design, the feasibility of an asymmetric hybrid stackup is currently being studied.
Asymmetric hybrid stackup offers greater flexibility and potential cost savings in high-speed traces routing2. However, the mechanical reliability risks in the asymmetric hybrid stackup are even more challenging than those in conventional hybrid PCB stackup. In this research, a team with diverse expertise, including design, material, and PCB manufacture process, was formed to study the effects of (1) different hybrid material combinations, and (2) various asymmetric hybrid stackup constructions on mechanical reliability performance using a qualitative approach. Unlike most other research that uses test coupons as the subject, a production-level data center mainboard design was used in this study, which provides more reliable test results and more accurate assessments.
Reliability test methods and results concerning warpage, delamination, via reliability, and brief signal Integrity comparison will be discussed in this paper. Recommendations on PCB manufacturing and design guidelines to mitigate the reliability risks associated with asymmetric hybrid PCB will also be provided.
Introduction
Reliability risks (warpage, delamination, conductive anodic filament, and via reliability) remain the major concerns in the usage of asymmetric hybrid PCB stackups. Conventional wisdom suggests that the manufacturing challenges and reliability risks of asymmetric hybrid PCB stackups are even higher than with symmetric hybrid PCB stackups. This research aimed to (1) understand the effects of different copper-clad laminate (CCL) material combinations and various constructions on the reliability performance of the asymmetric hybrid stackup, and (2) establish design and manufacturing guidelines to mitigate the reliability risks of the PCB, using a qualitative approach.
To read the entire article, which originally appeared in the August 2024 Design007 Magazine, click here.
Share on:
Suggested Items
SCHMID Group Unveils Revolutionary Hyper Loop System (HLS) for Precision Etching with Sustainable Technology
11/07/2024 | SCHMID GroupThe SCHMID Group is excited to introduce the Hyper Loop System (HLS), an innovative solution setting new standards in etching technology by combining high efficiency with sustainable benefits.
HBM5 20hi Stack to Adopt Hybrid Bonding Technology, Potentially Transforming Business Models
10/30/2024 | TrendForceTrendForce reports that the focus on HBM products in the DRAM industry is increasingly turning attention toward advanced packaging technologies like hybrid bonding.
RTX's Collins Aerospace Develops High-Voltage Power Components for Clean Aviation Project
10/29/2024 | RTXCollins Aerospace, an RTX business, has completed prototype development of a solid-state power controller and power distribution panel as part of the SWITCH project, supported by the European Union's Clean Aviation Joint Undertaking (Clean Aviation).
Elementary, Mr. Watson: The Gooey Centers of Hybrid PCB Designs
10/09/2024 | John Watson -- Column: Elementary, Mr. WatsonAnyone who knows me knows that I have a special relationship with food. Taking a twist on the words of Will Rogers, "I never met a buffet I didn't like." A balanced diet, to me, means having cupcakes in both hands. One of my favorite foods is cheeseburgers. One of my colleagues at Palomar College recently invited me out for a meal, and we ended up in a burger place in San Diego. I wanted to go the conventional and safe route: a double-patty cheeseburger. My friend insisted that I try the restaurant’s special: a peanut butter cheeseburger. “Really?” I told him. “What an interesting combination.” But he insisted I try it, and since I consider myself an adventurous person, I gave it a go.
Northrop Grumman Completes Hybrid SATCOM Demonstration, Connecting to Commercial Space Internet
09/25/2024 | Northrop GrummanNorthrop Grumman Corporation successfully completed its first over-the-air demonstration of a hybrid satellite communications (SATCOM) solution, providing seamless connection with Viasat and a commercial proliferated low Earth orbit (PLEO) communications provider