IPC Classes and Complying with IPC Standards for PCB Design

Zachariah Peterson
|  Created: October 5, 2020
IPC Classes and Complying with IPC Standards for PCB Design

Whether you work in electronics design, manufacturing, or even defense, the alphabet soup of standards organizations is extensive and may seem daunting. The IPC standards are among the most widely accepted and important standards for PCB designs. If you are a professional designer and you are designing consumer electronics products or more specialized systems, you’ll need to stay aware of the IPC standards.

These standards are meant to ensure performance and reliability and are accepted by a number of industries. These standards are meant to ensure the performance and reliability of PCBs and electronic products in a number of industries. Complying with these standards at the design level and during manufacturing becomes much easier when you use the right design software. Take a look at how Altium Designer can help you remain compliant with IPC standards.

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The only unified PCB design suite with design and verification features that can be tailored to IPC standards.

Among the many electronics standards organizations, the organization that all designers should be aware of is IPC. These industry standards are designed to ensure the reliability and manufacturability of printed circuits and other electronic assemblies. The goal of the IPC standards is to ensure that electronics products are reliable, safe, and manufacturable. No matter which industry you work in, IPC likely defines standards that specify important requirements for your products.

Very few people have ever read the entirety of the IPC standards, simply due to their breadth and depth. If you are a PCB designer, there are some very important standards with which you should become familiar. When you use the right design software with integrated compliance tools, it may be easier than you think to comply with IPC standards and design to different IPC product classes. Altium Designer’s integrated design rule engine lets you define important IPC standards as design constraints, which helps you comply with these important standards.

IPC Standards on PCB Design and Manufacturing

The IPC standards include multiple manufacturing requirements for all aspects of a printed circuit board. These manufacturing requirements ultimately translate back to design requirements, and designers need PCB design software to help ensure their boards will be compliant with IPC design requirements. Some examples include via and microvia manufacturing, solder joint strength requirements, solder mask material and thickness, material properties for substrates, and several other manufacturing requirements.

What IPC Sections are Relevant to PCB Design and Manufacturing?

There are many sections of the IPC standards, and not all sections are applicable to every circuit board design. Some important design standards that are meant to ensure mechanical strength and thermal stability are IPC 2152, IPC 4761, and IPC 6012E. The IPC-A-600 series includes many important standards for PCB manufacturing and electronics assembly. These standards have important consequences for PCB manufacturers and assemblers as they determine the parameters used in fabrication processes. Finally, the IPC-1752A Material Declaration Management standard defines reporting formats for data exchanged between designers, distributors, and manufacturers.

For component designers and PCB designers, IPC 7351 specifies footprint and land pattern requirements for SMT components. Component manufacturers and PCB designers should keep these specifications in mind when designing their pinouts and land patterns to ensure solderability and reliable electrical connections. Certain classes of designs,

Screenshot of the IPC Compliant Footprint Wizard in Altium Designer

You can design an IPC-7351 compliant component footprint in Altium Designer.

What Do PCB Designers Need to Know About IPC Classes?

The IPC standards define four product classifications. Class 1 defines requirements for general printed circuit boards with a limited life and simple functions. These boards are meant for one-time use or throwaway products. Class 2 defines design requirements for electronic products that require extended service life and on-demand performance. These boards tend to have more complicated functions than would be found in simple devices and are often part of a larger system, such as a computer or television.

Class 3 PCBs have tighter in-manufacturing tolerances and more stringent reliability requirements as opposed to Class 1 and Class 2 boards. Someone that is not a professional designer is likely designing a Class 1 circuit board. More complex products tend to be built to Class 2 or Class 3. IPC Class 3/A takes the Class 3 reliability requirements and applies them to military and/or aerospace electronic products. Other important standards organizations for military products include ISO, MIL, FAA, and SAE.

To get a more thorough view of IPC requirements as they apply to PCB manufacturing, you can view the IPC’s manufacturer’s checklist.

Differences Between IPC Class 2 and Class 3

Products defined as Class 3 must be built according to criteria that includes plating thickness, laminate/solder mask selection, PCB manufacturing processes, material qualifications, and quality inspection. The major differences between Class 2 and Class 3 are in the component placement requirements for SMT components. Class 3 places stricter cleanliness requirements on the assemblies, defines a definite plating thickness in through-hole vias, and plating thickness on the surface of PCBs.

PCB designers need to address all these fabrication requirements during the design phase. Addressing these issues as you design will prevent a redesign once you send your board to your manufacturer. Following important IPC standards on design and fabrication also helps ensure you have the highest possible board yield.

Screenshot of the PCB Rules and Constraints Editor in Altium Designer

Via design is an important aspect of reliability in different IPC class products.

How Altium Designer Helps You Stay Compliant

Altium Designer includes all the design tools you need for design, manufacturing, and documentation in an integrated design environment. These features are designed to be adaptable, ensuring your board will be compliant with IPC standards for PCB design. The power of Altium Designer is its rules-driven design engine, which allows you to define important IPC class standards as design rules and constraints.

Altium Designer Helps You Comply With IPC Standards for PCB Design

As you create your circuit board, the online DRC engine in Altium Designer checks your PCB layout against your design rules as you create your circuit board. Every design feature in the program reads from these design rules as you build your board. The verification features automatically check your design against standard and customized design rules, helping you remain compliant with IPC standards for PCB design.

Screenshot of the a panelized PCB in Altium Designer

You can ensure this panel obeys important IPC standards for PCB design when you use Altium Designer.

With the rules-driven design engine in Altium Designer, you can ensure important IPC standards for PCB design are automatically checked as you create your circuit board. No matter which IPC class you want to design to, you’ll be able to create high-quality circuit boards and take them to production with Altium Designer.

Altium Designer on Altium 365 delivers an unprecedented amount of integration to the electronics industry until now relegated to the world of software development, allowing designers to work from home and reach unprecedented levels of efficiency.

We have only scratched the surface of what is possible to do with Altium Designer on Altium 365. You can check the product page for a more in-depth feature description or one of the On-Demand Webinars.

About Author

About Author

Zachariah Peterson has an extensive technical background in academia and industry. He currently provides research, design, and marketing services to companies in the electronics industry. Prior to working in the PCB industry, he taught at Portland State University and conducted research on random laser theory, materials, and stability. His background in scientific research spans topics in nanoparticle lasers, electronic and optoelectronic semiconductor devices, environmental sensors, and stochastics. His work has been published in over a dozen peer-reviewed journals and conference proceedings, and he has written 1000+ technical blogs on PCB design for a number of companies. He is a member of IEEE Photonics Society, IEEE Electronics Packaging Society, and the American Physical Society, and he currently serves on the INCITS Quantum Computing Technical Advisory Committee.

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