The Knowledge Base: A Conference for Cleaning and Coating of Mission-critical Electronics
Defense Speak Interpreted: Is DARPA Still Around After CHIPS?
Beyond the Board: Orbital High Ground—Why Space Superiority Is Slipping Away
Showing Some Constraint: Design007 Magazine July 2025
July 10, 2025 | I-Connect007 Editorial TeamEstimated reading time: Less than a minute
Constraints shape the entire PCB industry, and every design decision introduces trade-offs, often leading to more trade-offs. Nearly every element on the board can become a constraint depending on the end product: component and drill sizes, trace widths and spacing, material choices, microvias, testing requirements, signal and power integrity, thermal demands, fabricator limitations, and supply chain risks. The list doesn't stop there. It can also include compliance with FCC, FDA, UL, and ITAR regulations.
Building a smart constraint strategy that balances electrical and manufacturing needs takes deep experience, often years in the making. Fortunately, our expert contributors, many of whom are also educators, bring exactly that level of insight. This month, we explore design constraints: the essential requirements, common challenges, and proven best practices for getting them right.
Share on:
Suggested Items
Elementary, Mr. Watson: Rein in Your Design Constraints
07/10/2025 | John Watson -- Column: Elementary, Mr. WatsonI remember the long hours spent at the light table, carefully laying down black tape to shape each trace, cutting and aligning pads with surgical precision on sheets of Mylar. I often went home with nicks on my fingers from the X-Acto knives and bits of tape all over me. It was as much an art form as it was an engineering task—tactile and methodical, requiring the patience of a sculptor. A lot has changed in PCB design over the years.
Beyond Design: The Metamorphosis of the PCB Router
06/18/2025 | Barry Olney -- Column: Beyond DesignThe traditional PCB design process is often time-consuming and labor-intensive. Routing a complex PCB layout can consume up to 30% of a designer’s time, and addressing this issue is not straightforward. We have all encountered this scenario: You spend hours setting the constraints and finally hit the Go button, only to be surprised by the lack of visual appeal and the obvious flaws in the result.
Siemens to Bring Advanced Timing Constraint Capabilities to EDA Design Flow with Excellicon Acquisition
05/19/2025 | SiemensSiemens has entered into an agreement to acquire Excellicon to bring its best-in-class software for the development, verification, and management of timing constraints to Siemens’ EDA portfolio of software for IC design
Elementary, Mr. Watson: Pushing Design Boundaries
05/29/2024 | John Watson -- Column: Elementary, Mr. WatsonOverconstraint: What a concept. Our first thoughts would be: What are we hurting by overconstraining a design? Isn't it better to be safe than sorry? What is meant by overconstraint? It means to apply excessive constraints. In engineering and mathematics, it's used when there are too many simultaneous equations to result in an exact solution. For example, fitting a line to many points is overconstrained because a line cannot be drawn simultaneously through all of the points. In PCB design, overconstraints always occur, including dimensional, electrical, manufacturing, and timing constraints. The list goes on.
Three Things to Improve High-Speed PCB Signoff, Part 2
09/27/2023 | Brad Griffin, Cadence Design SystemsAnother challenge for SerDes is losses within the channel design. At high speeds, dielectric material can be very lossy, making the appropriate selection of the right material, length, etc., critical for the channel. Many questions about stackup, trace widths, and height from the ground plane need to be defined up front. Simulating a signal with a topology explorer tool extracted from the design can be used to set up and run sweep parameters and push min/max length/spacing values into the Allegro schematic constraint manager (system capture).