XinAn PCB

IPC Standards & Classifications

Understanding IPC product types and performance classes for PCB manufacturing

What is IPC?

IPC (Association Connecting Electronics Industries) is the global trade association that develops and publishes standards for the electronics manufacturing industry. Originally founded in 1957 as the Institute for Printed Circuits, IPC now maintains over 300 active standards covering PCB design, fabrication, assembly, testing, and reliability. IPC standards are consensus-based documents developed by industry volunteers and represent accepted manufacturing practices worldwide. The most relevant IPC standards for bare PCB fabrication are IPC-6012 (Qualification and Performance Specification for Rigid Printed Boards), IPC-A-600 (Acceptability of Printed Boards), and IPC-2221/2222 (Generic/Sectional Standard on Printed Board Design). IPC-6012 defines the performance requirements that a finished PCB must meet, organized by product type and performance class. It covers dimensional tolerances, conductor requirements, hole quality, plating thickness, solderability, cleanliness, and electrical performance.

IPC Product Types

Type 1

Single-Sided & Double-Sided (No PTH)

Boards with conductors on one or both sides, without plated through-holes. Layer-to-layer connection (if double-sided) is achieved by mechanical means such as rivets, eyelets, or wire jumpers. These are the simplest PCB constructions.

Examples: Single-sided LED boards, simple consumer electronics, calculators, basic power supplies

Type 2

Double-Sided with Plated Through-Holes

Boards with conductors on both sides connected by plated through-holes (PTH). The copper barrel in the hole provides the electrical connection between top and bottom layers. This is the most common product type for general electronics.

Examples: Consumer electronics, industrial control boards, IoT modules, power converters

Type 3

Multilayer with Plated Through-Holes and/or Blind/Buried Vias

Boards with three or more conductor layers interconnected by plated through-holes and optionally blind or buried vias. Multilayer construction enables higher density, better signal integrity, and dedicated power/ground planes. The most demanding product type in terms of manufacturing process control.

Examples: Server boards, telecom equipment, automotive ADAS, medical devices, aerospace electronics

IPC Performance Classes

Class 1

General Electronic Products

Products where the primary requirement is function of the completed assembly. Cosmetic imperfections are acceptable. This class has the widest tolerances and fewest inspection criteria. Suitable for products with a limited service life or where occasional failure is not critical.

Examples: Toys, consumer gadgets, simple remote controls, disposable electronics

Class 2

Dedicated Service Electronic Products

Products where continued performance and extended life are required, but uninterrupted service is not critical. Some cosmetic imperfections are allowed within defined limits. This is the standard class for most commercial electronics manufacturing.

Examples: Communication equipment, industrial machinery, instrumentation, commercial computers, HVAC controls

Class 3

High-Performance Electronic Products

Products where continued high performance or performance-on-demand is critical. Equipment downtime cannot be tolerated, and the operating environment may be exceptionally harsh. This class imposes the tightest tolerances, most stringent inspection criteria, and highest reliability requirements.

Examples: Life-support medical devices, flight control systems, military weapons systems, automotive safety (airbag, ABS), satellite electronics

IPC-6012 Class 2 vs Class 3 Comparison

Parameter	Class 2	Class 3
Minimum Annular Ring (External)	≥ 50 μm (2.0 mil)	≥ 50 μm (2.0 mil) with no breakout
Minimum Annular Ring (Internal)	90° breakout allowed	No breakout allowed (full 360° ring)
Minimum Conductor Width Reduction	≤ 20% of minimum width	≤ 10% of minimum width
Minimum Conductor Spacing Violation	≤ 20% reduction from minimum	Not allowed
PTH Copper Plating Thickness (Barrel)	≥ 20 μm (0.8 mil) average	≥ 25 μm (1.0 mil) minimum
PTH Copper Plating Voids	≤ 3 voids, each ≤ 5% of barrel length	1 void maximum, ≤ 5% of barrel length
PTH Knee (Hole/Surface Junction)	≥ 5 μm	≥ 13 μm
Dielectric Thickness (Layer-to-Layer)	Per design within ±10%	Per design within ±10%, verified by microsection
Registration (Layer-to-Layer)	Per design requirements	Tighter tolerance, per design requirements
Surface Finish Solderability	Pass solder float test per J-STD-003	Pass solder float test, more stringent dwell time

Our IPC Compliance

XinAn PCB manufactures to IPC-6012 Class 2 as the default standard for all orders. Class 3 fabrication is available on request and must be specified at the time of quotation. Our incoming material inspection, process controls, and final inspection procedures follow IPC-A-600 acceptance criteria for the designated class. Cross-section analysis, plating thickness measurement, and solderability testing are performed per lot to verify compliance. All shipments include a Certificate of Conformance referencing the applicable IPC standard and class.