When failure is not an option, the bar for build quality rises. At PCB Power, we build for missions where electronics must perform, every time, under heat, vibration, and long service life. We specialize in IPC Class 3 PCB assembly for programmes where reliability cannot slip.
This blog explains the changes from standard builds, why they matter, and how we deliver the extra control, documentation, and proof you need.
Who Needs Class 3?
Think aerospace controls, medical devices, industrial safety systems, rail signalling, defence platforms, oil and gas monitoring, and satellites.
In these environments, even a minor assembly defect can escalate into system failure. IPC Class 3 exists to minimize that risk by tightening acceptance criteria and enforcing disciplined process control.
Class 3 vs Class 2: What Actually Changes?
At a high level, the difference between Class 2 and Class 3 assembly comes down to how much variation is allowed and how much evidence is required to prove a board was built correctly.
Process Controls That Protect Yield
Class 3 is as much about the journey as it is about the destination.
Class 3 reliability is not achieved by inspection alone. It is built into the process.
At PCB Power, the Class 3 PCB assembly process runs as a closed-loop process that reduces variation before it reaches your product.
Stencil and paste: aperture design for correct area ratio, paste lot traceability, and controlled storage and thawing.
Reflow: profiled per assembly with uniform ramp, soak, peak, and cool, then locked and monitored.
Through-hole soldering: barrel fill confirmed, with thermal reliefs and preheat set for consistent flow.
Class 3 success depends on aligning design intent with downstream assembly controls.
Request a quote with PCB Power to engage our team on stencil design and validated reflow profiling as part of your manufacturing plan.
Documentation, Inspection, and Proof
You are not buying promises. You are buying traceability.
Workmanship to spec: trained inspectors certify joints and leads to IPC class 3 acceptance criteria.
In-process checks: AOI after placement and after reflow, with X-ray on demand for hidden joints and vias-in-pad.
Records: travellers, reflow profiles, machine logs, paste lots, and inspection reports tied to serials.
This level of traceability is often as important as the assembly itself, especially for regulated or audited programs.
Why Build Class 3 With PCB Power
Experience where it counts: dedicated Class 3 lines run by operators trained on mission-critical work.
Tight process windows: controlled materials, validated profiles, and active SPC on key stations.
Transparent reporting: you receive the data that proves conformance, not just a pass label.
Fast, practical support: early DFM feedback, quick coupon runs, and clear hand-offs from NPI to production.
Contact our team to discuss your Class 3 requirements and next steps.
FAQs
1) What is Class 3 in simple terms?
It is a workmanship standard for boards that must work every time in harsh environments. It sets stricter rules for solder joints, cleanliness, materials, and proof.
2) Do I need to redesign for Class 3?
Sometimes. Minor footprint tweaks, via choices, and test access improvements often help.
3) Can you ship with RoHS and ITAR requirements?
Yes. We separate materials and documentation streams as required and provide the records your audit needs.
4) What is the best way to start?
Send your data pack with design notes and reliability targets. We will propose a Class 3 build plan, a small proof lot, and the documentation set that travels with every batch.
