The IPC-6012 standard defines rigid PCBs and divides them into three quality and reliability classes: 1, 2, and 3. Our guide compares IPC-6012 Class 1 vs. Class 3 boards. Learn more about their differences and applications.
Key Takeaways
- Standard’s Definition: The IPC-6012 standard outlines the performance and reliability requirements of rigid circuit boards.
- IPC-6012 Classes: The standard divides requirements into three different classes. Class 3 is the highest standard.
- Reliability vs. Performance: Class 3 boards are designed for high reliability, while class two types prioritize performance.
- Application Difference: Class 2 circuit boards find use in commercial electronics. Class 3 PCBs are built for critical applications and extreme operating conditions.
What is IPC 6012 Class 2 PCB Standard?
The IPC-6012 Class 2 standard is an industry classification for dedicated-service electronic products. It consists of PCBs that meet high-performance needs but can fail without posing severe risks or losses.
The standard provides manufacturing and testing guidelines that are less stringent than those of the Class 3 boards. For example, it allows cosmetic imperfections that do not affect the device’s functionality.
What is IPC 6012 Class 3 PCB Standard?
The standard outlines the quality and performance requirements of high-reliability electronics. The PCBs in this group should not fail. They also operate in conditions that make them more prone to damage.
Their design and manufacturing processes are highly controlled. They also undergo the most rigorous testing steps to ensure zero defects. An example is a medical PCB whose failure could lead to a loss of life.
Resource: https://www.researchgate.net
IPC 6012 Class 2 vs. Class 3 PCB
The IPC-6012 Class 2 and IPC Class 3 requirements vary widely. The PCBs differ in their performance, quality, and reliability expectations. Here is a side-by-side comparison to help you grasp the differences.
Reliability Requirements
Class 3 board reliability requirements are high with no room for failure. They can withstand various forms of damage, including extreme heat, high humidity, and mechanical stress.
Class 2 circuit boards are comparatively less reliable. They operate in milder environments and conditions. Their applications are also less critical with acceptable downtimes.
Manufacturing Tolerances
IPC-6012 Class 3 mandates stricter manufacturing tolerances to ensure mission-critical reliability. Key differences include:
– Annular Rings: While Class 2 allows for a 90° breakout, Class 3 requires a minimum 2-mil external annular ring, ensuring no breakout occurs and providing a more robust electrical connection.
– Copper Plating: Class 3 requires a minimum average through-hole copper thickness of 25 µm. Class 2 requires a minimum of 20 µm. This added thickness significantly reduces the risk of barrel cracking.
– Structural Integrity: These tighter standards ensure the PCB can withstand extreme thermal cycling and mechanical stress without electrical failure.
Inspections and Testing
Class 3 boards undergo more inspections and testing due to their zero-tolerance for defects. The tests are 100%. They include reliability tests, such as thermal cycling and accelerated life tests.
Class 2 inspection and testing needs are less intensive, as minor defects are permitted. That said, they are more rigorous than those of group 1 boards.
Acceptable Defects
Minor defects are acceptable in the Class 2 standard if they do not impair operation. These are typically visual errors, such as component placement defects or minor issues like tiny voids.
The Class 3 standard requires 100% compliance, with no permissible design or manufacturing defects. It doesn’t matter whether the defect is visual or functional.
Estimated Lifespan
Class 3 circuit boards are designed to last longer. They operate in harsher environments, which require their structures and materials to withstand extreme conditions.
Class 2 PCBs are durable, but not as long-lasting. Their operating environments are milder. Their applications are also not as critical in terms of reliability and life expectancy.
Cost Implications
The higher design, manufacturing, and testing requirements of a Class 3 circuit board significantly increase its cost. That’s in addition to its use of expensive high-performance materials and components.
In comparison, Class 2 circuit boards are less demanding to manufacture, which makes them cheaper. They also use less costly materials and parts, which further reduces their manufacturing costs.
Resource: https://www.designworldonline.com
IPC 6012 Class 2 vs. Class 3 Standard in Applications
The two circuit board types have diverse uses depending on application conditions and reliability requirements. It also depends on the desired lifespan and various other needs.
We use Class 2 PCBs when performance is crucial, but downtime is acceptable. Example applications include consumer electronics such as TVs, kitchen appliances, communication devices, computers, and office equipment.
Class 3 boards are reserved for critical applications where reliability and durability are crucial requirements. In these uses, the PCB must always operate. In other words, failure is unacceptable.
Common applications include devices and systems in the medical, automotive, military, and aerospace industries. The PCBs are also needed in harsh industrial conditions and marine environments.
Choosing Between IPC Class 2 and Class 3 Standards
The unique differences between the two IPC standard requirements define when to use each. The following are key selection parameters based on the application needs.
When to Use Class 2 Standard: Use this standard if the PCB is meant for dedicated commercial electronics where performance and long life are essential but not critical.
When to Use Class 3 Standard: Choose this standard for mission-essential electronics, such as life-support systems, or for harsh operating environments. The PCBs cost more but offer guaranteed reliability and long life.
Conclusion
The IPC-6012 standard classifies rigid PCBs based on their performance and other requirements, including manufacturing and testing methods. The information is helpful when you must choose a suitable standard to ensure reliability and compliance with industry standards.
Venture Electronics has the capacity to manufacture all types of IPC-6012 circuit boards, including classes 2 and 3. We adhere to strict IPC requirements for each standard, ensuring your PCB operates reliably in its application environment. Don’t wait any longer. Let us produce your next IPC-rated PCBA. Contact us now.
