Why Worry About IPC Standards for PCB Design?

When I got started creating my first boards, the last thing I was thinking about was producing a board at huge scale, or even at low volume. As a young student, the most important thing to me was getting my great ideas to work as I imagined. Once I started working in the electronics industry as a professional, I quickly realized that the alphabet soup of standards was a useful tool for designers and manufacturers alike.

Among the most important and widely accepted standards for PCB design, fabrication, and assembly are the IPC standards. The list of IPC standards for PCB design is extensive. This set of documents covers everything from plating on exposed copper, to bare board cleanliness. Manufacturers make sure to familiarize themselves with the fabrication and assembly portions of the IPC standards for PCB design, but PCB designers should do their best to understand the design portions of the IPC standards.

What’s in the IPC Standards for PCB Design?

The short answer is: everything! Every aspect of PCB design, fabrication, and manufacturing you’ve ever considered is most likely associated with some IPC standard. Obviously, the list is too long to repeat here, but some of the important design standards are covered in the IPC standards for PCB design. Before scanning through the list below, be sure you’ve familiarized yourself with some basic guidelines for PCB design.

IPC 6012: Acceptability Criteria

When designers are building a new rigid board to comply with IPC standards and ensure manufacturability, the IPC 6012 standard is the place to get basic requirements. This set of standards, as well as the IPC-A-600 standard, will tell you what a manufacturer looks for when they receive your board. These standards address solderability, conductor width and spacing, structural integrity, and substrate material requirements. Some related standards are:

  • IPC-6011: Generic Performance Specification for Printed Boards
  • IPC-6013: Specification for Printed Wiring, Flexible and Rigid-Flex
  • IPC-6016: Qualification and Performance Specification for High Density Interconnect (HDI) Structures
  • IPC-6018: Qualification and Performance Specification for High Frequency (Microwave) Printed Boards
  • IPC- 6202: Performance Guide Manual for Single- and Double-Sided Flexible Printed Wiring Boards
  • IPC-2251: Design Guide for the Packaging of High Speed Electronic Circuit
  • IPC-7351B: Generic Requirements for Surface Mount Design and Land Pattern Standards

IPC-4761: Via Plugging

If you plan to use plugged vias, or plated-over vias, then you’ll need to review this important standard for via design. You’ll need to ensure your plugging and/or plating strategy is properly designed to ensure these structures do not fail during operation.

IPC-2221: High Voltage Clearance Standards

This standard defines safe clearance distances between conductive elements in high voltage PCBs. This standard also provides requirements on material quality, layout guidelines, and much more. A related specification for flexible PCBs is the IPC-2223 standard.

IPC-2152: High Voltage Clearance Standards

The new IPC-2152 standard provides much better guidance on designing boards with the appropriate trace width to prevent excessive temperature rise. This standard also addresses the required distance between traces and distances to copper planes.

IPC-2141A: High-Speed Controlled Impedance Standards

If you’re designing a high speed or high frequency board that requires controlled impedance routing, the IPC-2141 standard contains some impedance formulas for different trace geometries. However, the equations in these standards are known to be less accurate than other equations for microstrip and stripline impedance. Read more about the controversy here.

IPC standards for PCB design flowchart

The list of relevant IPC standards for PCB design and their application areas.

Take Advantage of Constraints in Your Design Software

Complying with IPC standards for PCB design becomes much easier when you use the right design software. I’ve never met anyone that can keep track of all the important IPC standards, and it doesn’t hurt to use design software that can help ensure compliance. If you plan to produce your board at scale, you need to ensure that important IPC design specifications are encoded in your EDA software as rules and constraints.

EDA software plays an important role in ensuring compliance with IPC standards for PCB design. EDA software, specifically for circuit and PCB design, is highly adaptable and includes tools that allow you to create nearly any conductive structure and layout you can imagine. Many design choices you make might be electrically correct, but they may not comply with IPC standards, and they may not be manufacturable. However, if you choose the right design software, you can identify DFM violations and any design choices that don’t comply with IPC standards.

The best software for PCB design will include important IPC standards as editable design constraints. If your board needs to obey more stringent standards than those defined by the IPC, you’ll need to edit an existing constraint or define a new one. While this takes some up-front time, you’ll be able to spot any design choices saves you from making a costly redesign before production.

Defining clearance constraints using IPC standards for PCB design

Example of a clearance constraint you can define in your next PCB design

There are a number of other important standards that play a role in PCB design software. Some of these have nothing to do with electrical functionality of an assembled board, and instead focus on footprints, symbols, and models used for components in PCB design software. Other standards bodies, such as the International Electrotechnical Commission (IEC) and Underwriters Laboratories (UL), set standards on PCB functionality, assembly, and their incorporation in specific products.

If you want to ensure your next board will comply with IPC standards for PCB design, you can take advantage of the rules-driven online design platform in Upverter®. This easy-to-use browser-based platform is ideal for designing new PCBs from start to finish. You can easily pick an existing template from a vast range of open-source hardware projects, and important IPC and DFM standards are defined as design constraints automatically.

You can sign up for free and get access to the best browser-based PCB layout editor, schematic editor, and component database. Visit Upverter today to learn more.

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