Tung kobber printpladesamling til højspændingselektronik

Highleap elektronik provides heavy copper PCB assembly services for high-current electronics, power control boards, BMS boards, EV charger electronics, industrial power modules and thermal-management applications. Heavy copper PCBAs require coordination between PCB fabrication, soldering process, component selection, current path, thermal design and inspection. Highleap manufactures and assembles boards according to customer-approved files, drawings, BOMs and test requirements.

Heavy copper generally refers to PCB constructions using thicker copper than standard signal boards. The exact copper weight should always be defined in the stackup by layer. A heavy copper board is not automatically safe for a given current; current capacity depends on copper thickness, trace width, plane area, allowable temperature rise, airflow, layer position, substrate material and product environment. The product owner should validate electrical and thermal performance at system level.

For related project pages, see power electronics PCB assembly, BMS PCB-samling og EV oplader PCB samling.

Heavy Copper PCB Assembly Capability

Heavy copper manufacturing role

Highleap can support heavy copper PCB fabrication and assembly when the construction is defined clearly and the build is within agreed capability. The drawing should state copper weight by layer, finished thickness, surface finish, solder mask, hole plating, critical dimensions, current-carrying areas and inspection requirements. When assembly is included, the package should also identify high-current components, terminals, connectors, heat-generating parts and mechanical interfaces.

Typical heavy copper PCBA uses

Fabrication and assembly coordination

Heavy copper changes both bare board production and assembly. Etching thick copper requires larger design allowances than fine signal copper. Large copper areas affect reflow balance. Through-hole terminals may need controlled solder fill. Thermal pads may need X-ray or special inspection if required. For best results, heavy copper should be reviewed as a complete PCB and PCBA process rather than a simple material upgrade.

Copper Thickness and Current-Carrying Requirements

Current capacity depends on the full design

Copper weight is only one part of current capacity. The designer should also consider trace width, copper area, number of layers, via quantity, allowable temperature rise, ambient temperature, cooling condition, board thickness, nearby heat sources and enclosure airflow. IPC-2152 is commonly used as a reference for current-carrying capacity in printed board design, but final product validation remains the responsibility of the product owner.

Design impact of thicker copper

Thicker copper can improve current carrying and heat spreading, but it also affects minimum trace and gap, etch compensation, solder mask definition, board thickness and cost. Fine-pitch components placed near thick copper areas may create assembly challenges. If the board combines control circuitry and high-current copper, the layout should separate sensitive components from high-heat and high-mass regions when possible.

Via and plane sharing

Current may move between layers through via arrays or plated features. Via count, diameter, plating thickness and layout determine how current and heat are shared. If a via array is part of a current path, it should not be treated as ordinary stitching. The drawing should identify critical via groups and any fill, cap or inspection requirement.

Termisk styring og varmeafledning

Heat spreading through copper

Heavy copper can spread heat from power components, but it does not replace a complete thermal design. Heat must leave the board through copper planes, vias, heat sinks, airflow, enclosure contact or thermal interface materials. If the board relies on a baseplate or chassis, the mechanical interface must be included in the assembly notes.

Thermal vias and exposed pads

Power devices with exposed pads may need thermal vias under or near the package. Via design should balance heat transfer, solder voiding and manufacturability. Open vias under pads can cause solder wicking; filled or capped vias may add cost but improve assembly consistency. The customer should define the via strategy based on product requirements.

Component spacing around heat sources

Heat-sensitive components such as electrolytic capacitors, sensors, optocouplers and small signal ICs should be placed with thermal exposure in mind. From the manufacturing side, spacing also helps inspection and rework access. Heavy copper boards often have large components and high thermal mass, so crowded placement can increase both reliability and assembly risk.

SMT and Through-Hole Assembly on Heavy Copper Boards

Reflow thermal balance

Heavy copper areas absorb heat differently from light copper signal areas. This can create uneven soldering conditions across the board. Stencil design, solder paste selection, reflow profile, pad geometry and component placement should be reviewed. Large copper pads may need thermal relief or process planning depending on the electrical and thermal requirements.

Through-hole power parts

Heavy copper boards commonly use through-hole connectors, terminals, relays, transformers and large capacitors. These components may need wave soldering, selective soldering or controlled manual soldering depending on design and quantity. Hole size, annular ring, copper thickness and thermal relief affect solder fill. If a solder fill percentage or inspection requirement is mandatory, it should be written into the drawing or assembly notes.

Inspection challenges

Heavy copper can make visual inspection more important and sometimes more difficult. Large solder joints, hidden pads, thermal pads and thick copper edges may need specific inspection instructions. X-ray can be used for selected hidden joints if required by the customer. Microsection may be requested for plated-hole evaluation when reliability requirements justify it.

Soldering, Reflow and Thermal Balance Challenges

Large copper heat sinking

Large copper areas can pull heat away from solder joints during reflow or through-hole soldering. This may cause insufficient wetting if the process is not adjusted. At the same time, overheating smaller components to compensate can create damage risk. A balanced process uses design review and process settings rather than excessive heat.

Stencil and solder paste planning

Power devices, thermal pads and large terminals may require special stencil apertures or paste control. The goal is to provide enough solder for thermal and mechanical reliability while avoiding bridging, floating, voiding or solder balling. If the product has strict void limits, the acceptable limit and inspection method should be defined by the customer.

Manual soldering limits

Manual soldering may be appropriate for prototypes or selected parts, but it should not be assumed for high-volume repeatability unless the process is controlled and documented. Large terminals, thick copper and high thermal mass can require operator skill and thermal control. For production, selective soldering or tooling may be more repeatable when the design supports it.

Inspection and Reliability Checks

Fokusområder for inspektion

• High-current trace and copper area quality.
• Plated-through-hole quality for terminals and via arrays.
• Solder fill and wetting for through-hole power components.
• Thermal pad solder quality for power semiconductors.
• Connector seating, orientation and mechanical clearance.
• Board flatness, outline and mounting interface.

Dokumentationskrav

Documentation may include material record, stackup confirmation, electrical test, inspection report, microsection, first article report or customer-defined functional test record. These should be requested before quotation. If a board will be used in a high-reliability product, the documentation package should reflect the risk level rather than only the lowest build cost.

Reliability considerations

Reliability depends on product design, operating current, temperature cycling, mechanical support, solder joint quality, component rating and environment. Heavy copper can support current and heat spreading, but it does not guarantee reliability alone. The complete assembly should be reviewed and validated under the customer’s intended use conditions.