Thick Copper Bare PCB Fabrication
Heavy Copper PCB Manufacturing
Custom heavy copper PCBs up to 12 oz for high-current and power-electronics designs. PCBELEC combines layer-specific copper requirements, fabrication-focused DFM review and prototype-to-production support in one bare-board manufacturing service.
Send your board files, stackup and target copper requirements to sales@pcbelec.com
- Copper Weight Up to 12 oz
- Engineering Preparation Stackup & DFM Review
- Fabrication Orders Prototypes to Production
Heavy Copper / Thick Copper PCBs
What Is a Heavy Copper PCB?
A heavy copper PCB, also called a thick copper PCB, uses increased copper thickness on selected conductive layers. Heavy-copper constructions commonly start around 3 oz/ft² and are used in power supplies, motor drives, industrial power and other high-current designs.
Thicker copper increases the conductor cross-section for a given trace width. The resulting current and temperature performance still depends on the conductor geometry, layer position, surrounding copper and operating conditions.
PCBELEC manufactures heavy copper bare PCBs up to 12 oz, with copper requirements defined alongside the stackup, conductor rules and fabrication notes.
Larger Conductor Cross-Section
Use specified copper thickness and trace width together to define the conductor geometry for the intended power path.
Power and Control Layer Planning
Plan power conductors and control routing within the board stackup, with copper requirements assigned to the relevant layers.
Layer-Specific Copper Requirements
Identify the copper on each layer rather than assuming that one board-level copper weight applies everywhere.
Copper Definition & Stackup Planning
Specify Copper Weight by Layer
A note such as “6 oz PCB” does not fully define a multilayer build. Identify the copper requirement on each conductive layer and state whether it refers to starting foil or finished copper.
Illustrative Stackup / Layer-Specific Copper
Starting Foil Is a Process Input
Starting copper describes the foil before circuit processing. It is not automatically the same as the final conductor thickness after etching and any required plating.
Finished Copper Defines the Result
State the required finished conductor thickness and acceptance basis. Distinguish a nominal target from a minimum requirement, especially on the power-carrying layers.
Hole-Wall Copper Is a Separate Requirement
Define plated-hole copper independently from the surface conductors. A heavy outer-layer copper specification does not, by itself, establish the required hole-wall copper thickness.
Make the Copper Specification Unambiguous
Swipe horizontally to view the full specification guide.
| Specification Item | What It Describes | Include in the Fabrication Package |
|---|---|---|
| Starting copper foil | Copper foil before conductor processing and additional plating. | Identify the layer and foil requirement where the starting material is a controlled design input. |
| Finished outer-layer copper | Outer conductor copper after the relevant fabrication processes. | State the finished thickness, units, minimum or nominal basis and applicable acceptance criteria. |
| Inner-layer copper | Copper requirements for each internal conductive layer. | Identify the required foil and any finished-thickness acceptance requirements after processing. |
| Plated-hole copper | Copper deposit on the walls of specified plated holes. | Define the hole-wall copper requirement separately from surface copper weight. |
Copper Weight & Board Construction
Heavy Copper PCB Manufacturing Capabilities
PCBELEC supports heavy-copper bare-board fabrication with separately defined inner and outer copper requirements. Match the copper weight, conductor rules and board construction as one complete manufacturing specification.
- Outer-Layer Copper 3–12 oz/ft² Define the finished copper requirement on each outer layer.
- Inner-Layer Copper 3–10 oz/ft² Assign copper requirements to the designated internal layers.
- Board Construction 1–30 Layers Layer count and copper distribution are reviewed together in the stackup.
Copper Thickness and Conductor Rules
Use the copper-specific trace and spacing references below when preparing the layout. Identify the applicable copper layer and finished conductor requirements in your files.
Swipe horizontally to view all specification details.
| Specification Item | Range / Design Reference | Fabrication Definition |
|---|---|---|
| Outer-layer copper | 3–12 oz/ft² | Specify the finished copper thickness, minimum or nominal basis and applicable acceptance criteria. |
| Inner-layer copper | 3–10 oz/ft² | Identify the copper requirement on each internal layer in the released stackup. |
| Trace / space at 3 oz |
8 / 8 mil Approx. 0.20 / 0.20 mm | Layout reference for 3 oz copper; identify critical conductor widths and clearances for DFM review. |
| Trace / space at 6 oz |
12 / 12 mil Approx. 0.30 / 0.30 mm | Review the conductor pattern and etching requirements together with the specified copper thickness. |
| Trace / space at ≥8 oz |
16 / 16 mil reference Approx. 0.40 / 0.40 mm | Final conductor rules follow the selected copper weight, feature geometry and agreed DFM. |
| Plated-hole copper | Separately specified | Define hole-wall copper, finished hole sizes and related acceptance requirements independently from surface copper. |
Trace / space values are design references, not electrical-current ratings or universal limits for every stackup. Metric values are rounded equivalents.
Board Construction and Process Requirements
Swipe horizontally to view the complete table.
| Manufacturing Item | Configuration | Define with the Order |
|---|---|---|
| Layer count | 1–30 layers | Release the complete layer order, copper distribution and dielectric construction. |
| Finished board thickness | Stackup-defined thickness | Specify the finished thickness, tolerance and any critical local mechanical requirements. |
| Laminate materials | FR-4, high-Tg FR-4 and halogen-free FR-4 | Identify the material grade or required thermal and electrical properties. |
| Special board construction | Aluminum-based and hybrid builds | Provide a defined construction drawing; identify metal-base features separately from conductor copper thickness. |
| Surface finish | ENIG, ENEPIG, immersion silver, immersion tin, OSP and lead-free HASL | Select the required finish and identify any local or special finish requirements. |
| Solder mask | Mask system suitable for the specified copper profile | Define openings, exposed power copper and critical mask coverage or registration requirements. |
| Fabrication verification | Electrical testing and specified inspection requirements | Include acceptance criteria, critical dimensions and any requested test or inspection records. |
Layout, Stackup & Fabrication Preparation
Heavy Copper PCB Design for Manufacturability
Prepare the layout around the actual copper thickness and board construction. PCBELEC reviews conductor geometry, hole structures, lamination and mask requirements together before fabrication.
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Trace Width, Spacing & Etching
Use conductor rules matched to the specified copper thickness. Review narrow gaps, neck-downs and isolated features so etching compensation does not obscure the intended finished geometry.
Define for Review Copper by layer, critical finished widths and minimum electrical clearances.
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Resin Fill Between Heavy Conductors
Review the depth and spacing of heavy-copper patterns with the selected dielectric construction. Plan resin flow and fill around the conductor profile as part of the lamination stackup.
Define for Review Copper profiles, dielectric requirements, dense copper regions and isolation areas.
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Hole Structures & Interlayer Paths
Define finished hole sizes, annular rings and hole-wall copper separately. Review the board thickness, drilling and plating access together with the intended interlayer connections.
Define for Review Hole table, plating requirements, connection details and any via treatment.
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Stackup Balance & Copper Distribution
Review copper weight and distribution across the complete stackup. Identify large unbalanced copper areas and any routing regions that must remain unchanged during manufacturing preparation.
Define for Review Released stackup, copper distribution, keepouts and drawing-specific flatness criteria.
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Pad Connections & Thermal Reliefs
Identify pads that require solid connections and those using thermal reliefs. Define the connection geometry explicitly so current-path requirements and later soldering needs remain aligned.
Define for Review Pad style, spoke geometry, neck-downs and any no-change power connections.
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Solder Mask Over Thick Copper
Review mask coverage over conductor steps, openings around large pads and the available mask webs. Identify intentionally exposed copper separately from areas requiring full mask coverage.
Define for Review Mask openings, exposed power areas, critical dams and registration requirements.
Manufacturing Spacing Is Not an Insulation Rating
Copper-specific line and space references describe fabrication geometry. Determine electrical clearance and creepage from the operating voltage, environment and applicable product requirements.
Control Changes to the Power Path
Flag critical conductor dimensions, copper areas and connection features that require approval before modification. Keep the final artwork, stackup and fabrication notes on the same design revision.
Copper, Construction & Electrical Integrity
Copper Thickness and Fabrication Verification
Verify the finished heavy-copper PCB against the approved stackup, fabrication drawing and acceptance requirements. Conductor copper, plated-hole copper and electrical integrity are defined and checked as separate characteristics.
Copper Requirements
Identify the relevant layer, finished conductor requirement and hole-wall copper specification instead of relying on one board-level copper label.
Board Construction
Check the released stackup, critical dimensions and specified workmanship criteria for the actual heavy-copper build.
Bare-Board Electrical Test
Verify continuity and isolation against the approved test data to identify open or short circuits before shipment.
Define What Must Be Verified
Swipe horizontally to view the full verification guide.
| Verification Area | Inspection Focus | Specify with the Order |
|---|---|---|
| Conductor copper thickness | The copper requirement on the designated outer and inner layers, using the agreed thickness definition. | Layer identification, units, minimum or nominal basis, acceptance limits and any required measurement locations. |
| Plated-hole copper | Hole-wall copper and the specified plated-hole construction, independently of surface copper weight. | Hole types, finished hole sizes, copper requirements and any specified sectioning or sampling criteria. |
| Finished dimensions | Board thickness, routed profile, critical conductor geometry and designated mechanical features. | Dimensioned drawing, datums, tolerances and features requiring recorded inspection results. |
| Construction and workmanship | Applicable criteria for the laminate, conductor pattern, solder mask and surface finish. | Acceptance standard and revision, customer-specific criteria and any requested cross-section evaluation. |
| Electrical continuity and isolation | Intended bare-board connections and isolation between nets, checked against the approved test data. | Test-data reference, electrical acceptance requirements and any requested test summary. |
Inspection methods, locations, sampling and report deliverables follow the agreed order requirements. Identify any special verification needs before fabrication.
Bare-board electrical testing does not replace loaded temperature-rise testing or product-level thermal validation. Define those application checks separately for the completed power system.
Bare PCB Testing & InspectionEngineering Samples to Repeat Orders
Heavy Copper PCB Prototypes and Production
PCBELEC supports heavy-copper bare PCB orders from engineering samples through small batches and production. Carry the approved copper definition, stackup and fabrication requirements forward as the design moves between build stages.
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01 / Engineering Samples
Heavy Copper PCB Prototypes
Fabricate samples for your mechanical, electrical and application evaluation. Identify the intended copper thickness and board construction so the prototype represents the features you need to assess.
Define for This BuildSample quantity, layer-specific copper, stackup, critical conductor dimensions and design revision.
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02 / Pilot & Small Batch
Low-Volume Heavy Copper PCBs
Move the selected design into a limited fabrication run. Incorporate approved prototype changes and release the copper, hole and mask requirements for the next manufacturing stage.
Define for This BuildReleased files, updated fabrication notes, order quantity and required inspection records.
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03 / Production & Reorders
Production Heavy Copper PCBs
Manufacture repeat builds against the approved board specification. Reference the correct part number, revision and agreed acceptance requirements when preparing production orders.
Define for This BuildProduction quantity, delivery schedule, approved revision and changes from the previous order.
Include your required quantity and delivery date with the heavy-copper fabrication package.
Heavy Copper Bare PCB Fabrication Inquiry
Request a Heavy Copper PCB Quote
Send your board files, layer-specific copper requirements and order details for engineering review and quotation. Include the released stackup and fabrication drawing so the copper, conductor geometry and board construction are defined together.
Include with Your Inquiry
- Manufacturing Files Gerber files, NC drill data, routed outline, fabrication drawing and design revision.
- Layer-Specific Copper Inner and outer copper requirements, starting or finished basis, units and acceptance limits.
- Stackup & Materials Layer order, material requirements, dielectric construction and finished board thickness.
- Critical Features Power-conductor dimensions, plated holes, hole-wall copper and any no-change connection features.
- Finish & Verification Surface finish, mask requirements, acceptance criteria and requested inspection records.
- Order & Delivery Quantity, target delivery date, shipping destination and previous order reference, where applicable.
Send Your Heavy Copper PCB Requirements
Use the form below to share your contact details, order quantity and manufacturing files. Add the layer-specific copper, stackup, critical dimensions and documentation requirements in your project description.
- You may also email your fabrication package to sales@pcbelec.com.
- Fields marked with an asterisk (*) are required.
- PCBELEC will use the contact details and project information you submit to respond to this inquiry.
Copper Specifications & Ordering
Heavy Copper PCB FAQ
Answers to common questions about copper thickness, current paths, stackup definition and heavy-copper bare-board fabrication.
Preparing an inquiry? Include the copper requirements for each layer, not only a board-level copper label.
View the Quotation ChecklistAre heavy copper and thick copper PCBs the same thing?
The terms are commonly used for PCBs with increased conductor copper thickness. Naming thresholds vary between suppliers, so the fabrication package should state the actual copper requirement on each layer.
Heavy copper describes the circuit conductors, not necessarily a copper-core or metal-base construction.
Is a 12 oz PCB an extreme copper PCB?
Terminology varies. Extreme copper generally refers to substantially thicker copper constructions than ordinary heavy-copper builds; some industry references use the term for copper above 20 oz/ft².
This service page specifies PCBELEC heavy-copper fabrication up to 12 oz. Use the numerical copper requirement rather than the marketing term to define your order.
Can inner and outer layers use different copper weights?
Yes. Assign copper requirements to the relevant power and routing layers in the stackup. PCBELEC's listed ranges for this service are 3–12 oz/ft² on outer layers and 3–10 oz/ft² on inner layers.
Review the complete combination of copper, layer count and dielectric construction together rather than assuming that every maximum applies simultaneously.
Should I specify starting copper or finished copper?
State which requirement applies. Starting foil describes a process input, while finished copper describes the resulting conductor thickness after relevant processing.
Identify the layer, units and minimum or nominal basis. Define hole-wall copper separately from surface conductor copper.
How much current can a heavy copper PCB carry?
Copper weight alone does not establish a current rating. Conductor width and length, layer position, surrounding copper, allowable temperature rise and operating conditions all influence the result.
Provide the intended current path and application conditions as design context. Verify the completed product under its specified load and thermal conditions.
Does thicker copper require wider trace spacing?
Increasing copper thickness changes the etching and conductor-profile requirements. Wider spacing may be needed for a manufacturable pattern, so use rules matched to the selected copper thickness.
Manufacturing line-and-space references do not replace the clearance and creepage requirements of the electrical application.
What affects heavy copper PCB cost and lead time?
Key inputs include copper thickness, layer count, board area, conductor geometry, hole structures, material, surface finish, quantity and inspection requirements.
Send the released files, target quantity and required delivery date so the quotation reflects the actual manufacturing package.
Can I use the same specification for prototypes and production?
Yes. Carry the approved copper, stackup and acceptance requirements into the production release. Identify any changes to power conductors, plated holes, materials or fabrication notes.
Reference one matching revision across the artwork, drill data, stackup and drawing. Request any required inspection records with the order.
