American Made Advocacy: Success in Washington Requires Patience, Persistence, and Sustained Focus
The Government Circuit: News on Defense Electronics, Europe, and Sustainability
Defense Speak Interpreted: SWaPing Nanosatellites for Defense Systems
Advanced Packaging Means Advanced Routing Issues
January 26, 2023 | Kris Moyer, IPCEstimated reading time: 1 minute
In today’s ever-shrinking world of electronics designs, the use of BGA parts with very fine pitch features is becoming more prevalent. As these fine-pitch BGAs continue to increase in complexity and user I/O (number of balls), the difficulty of finding escape routes and fan-out patterns increases. Additionally, with the shrinking of silicon geometry leading to both smaller channel length and increased signal integrity issues, some of the traditional BGA escape routing techniques will require a revisit and/or adjustment to allow for not only successful fan-out, but also successful functioning of the circuitry of the BGA design.
Historically, BGAs could be routed using traditional full through-via structures, with dog-bone traces off the BGA pad. These BGAs were typically 1.27 mm in pitch and had sufficient clearance between the pads to place a Class 3 Level A via without violating any design rules. Additionally, the feature sizes of these packages were sufficient to fabricate in 1-ounce copper without any issues. With increases in chip complexity and I/O density, most BGA packages are now 1 mm or smaller pitch, with some packages as small as 0.4 mm pitch. With these finer pitch packages, it is no longer possible to use traditional full-thru via structures under the BGA. This, in turn, will require the use of sequential lamination and micro-via structures in order to successfully escape route the BGA. Figure 1 shows a comparison between the package and feature sizes of 484-ball 1 mm pitch BGA (U100) and a 100-ball 0.4 mm pitch BGA (U101).
First, we look at the 1 mm pitch part, then evaluate what it will take to escape all balls to the outside perimeter of the BGA. For this evaluation, we will only consider the use of stacked microvias. Staggered microvias will also work, but require significantly more board area. Additionally, the stackup will assume dual stripline for all internal signal layers.
To read this entire article, which appeared in the January 2023 issue of Design007 Magazine, click here.
Share on:
Suggested Items
Global PCB Connections: Following DFM Rules Leads to Better Boards
12/18/2024 | Jerome Larez -- Column: Global PCB ConnectionsAs a PCB field applications engineer, ensuring smooth communication between PCB designers and fabricators is one of my frequent challenges. A critical part of that dialogue is design for manufacturing (DFM). Many designers, even experienced ones, often misunderstand or overlook important DFM considerations. They may confuse design rules with manufacturing minimums, leading to technically feasible designs that are difficult or costly to produce. In this column, I will clarify some common DFM guidelines and help designers understand the difference between “design rules” and “minimums” while sharing best practices that will simplify the production process and ensure the highest quality PCB.
Sayonara to the Last Standing Copper Foil Plant in North America
12/17/2024 | Marcy LaRont, I-Connect007In July 2021, PCB007 Magazine published an interview with Michael Coll and Chris Stevens of Nippon Denkai about the new acquisition by Nippon Denkai of the last-standing ED foil manufacturer in North America. The plant in Augusta, Georgia, was formerly owned by Oak Mitsui, Inc. and had been purchased by Nippon Denkai the previous March, after which significant investment was made with the expectation of providing more jobs.
SCHMID Group Unveils Enhanced InfinityLine H+ for Electroless Copper Deposition
12/16/2024 | SCHMID GroupThe SCHMID Group, a global leader in high-tech solutions for the electronics industry, proudly announces significant updates to its flagship InfinityLine H+ Electroless Cu system. Specifically designed for the production of high- performance advanced packaging applications using mSAP and SAP processes, the system reflects SCHMID’s expertise in horizontal electroless copper deposition.
OKI Develops PCB Technology with Stepped Copper Coin Insertion to Achieve 55 Times Better Heat Dissipation in Outer Space
12/12/2024 | BUSINESS WIREThe OKI Group printed circuit board (PCB) business company OKI Circuit Technology has successfully developed multilayer PCB technology with stepped copper coin insertion to achieve 55 times better heat dissipation compared to conventional PCB. The stepped copper coin is offered in two types, circular and rectangular, to suit the shape of the electronic component mounted on the PCB. OTC is working to develop mass-production technologies with the aim of introducing PCBs incorporating this new technology into markets for compact devices or devices used in outer space or other environments where air cooling technology cannot be used.
Fresh PCB Concepts: PCB Plating Process Overview
12/12/2024 | Team NCAB -- Column: Fresh PCB ConceptsIn this installment of Fresh PCB Concepts, Mike Marshall takes the helm stating: PCBs have been the platform for the interconnection of electronic components for decades. Because of process costs and other constraints, such as mechanical properties or size limitations of the alternatives, PCBs will remain the standard low-cost interconnection technology. Rapidly increasing performance and functionality requirements of wireless and high-speed devices have challenged the development and implementation of new manufacturing solutions.