3 oz Copper PCBs - Heavy Copper Manufacturer

2 oz copper on a PCB measures approximately 70 micrometers (µm) or about 2.8 mils in thickness. It is double the thickness of standard 1 oz copper (35 µm / 1.4 mils). 2 oz copper is classified as medium-weight copper and is commonly used in power distribution, industrial equipment, and applications where moderate current capacity and improved heat dissipation are required.

A PCB is classified as heavy copper when the copper weight exceeds 3 oz per layer (above 105 µm). FX PCB supports heavy copper from 3 oz up to 20 oz (700 µm), covering medium (2–4 oz), heavy (5–10 oz), and ultra-heavy (10–20 oz) classifications, enabling designs for extreme current loads, high thermal management, and mission-critical environments.

3 oz and heavier copper PCBs are used across aerospace, military, automotive (including EV modules), medical devices, industrial power systems, nuclear and solar energy, UPS systems, rail traction, welding equipment, and telecommunications. Their high current capacity and superior thermal performance make them indispensable wherever standard PCBs would fail under load.

For 3–4 oz copper, FX PCB supports up to 24 layers in sample production and 20 layers in mass production. For 5–6 oz copper, the maximum is 20 layers (sample) and 16 layers (mass production). As copper weight increases to 7–12 oz, the maximum layer count reduces to 12 layers (sample) and 10 layers (mass production) to maintain structural integrity.

Heavy copper PCBs leverage copper's exceptional thermal conductivity of 401 W/mK to dissipate heat rapidly and uniformly across the board. Thicker copper traces reduce electrical resistance and thermal resistance simultaneously, preventing hotspots, increasing thermal strain endurance in extreme environments, and eliminating the need for bulky external heatsinks in many high-power designs.

FX PCB holds ISO9001, ISO14001, and ISO13485 certifications, along with IPC-A-610 Class 2/3 compliance, UL listing, and full RoHS and REACH compliance. These certifications cover quality management, environmental management, medical device manufacturing standards, and workmanship standards, ensuring heavy copper PCBs meet the stringent requirements of aerospace, medical, automotive, and industrial customers worldwide.