Overview

A custom brass busbar is a flat, burr-free current-carrying part photochemically machined from C2600, C2680 or C2800 brass sheet, used wherever a power assembly needs a shaped conductor rather than a stamped strip. Designers move to an etched conductor when one piece must carry multiple tabs, mounting slots and stepped profiles, because chemical machining cuts the outline and half-etched bend lines without a die. Ampacity is calculated from the finished cross-section, so thickness and minimum web width are fixed first, then the artwork is compensated for the etch factor. What leaves the line is a flat conductor with clean edges that seats on a mating surface without rocking.

Flatness matters as much as conductivity here. A busbar that bows by even 0.1 mm over a 100 mm contact land raises contact resistance and creates a hot spot under load, so the process avoids the roll-over and heat tint that stamping and laser cutting leave behind. Tin or nickel plating is applied after etching to keep the brass from oxidising at the joint, and adhesive or film insulation can be laminated to selected faces. When a drawing calls for tight current sharing across parallel tabs, that is where a well-controlled custom brass busbar process pays for itself in stable joint temperature.

Parameter Window

• Available Materials: brass C2600/C2680/C2800 (H62/H65 equivalents), phosphor bronze C5100 on request
• Material Thickness Range: 0.2–2.0 mm, with 0.5–1.2 mm typical for power distribution tabs
• Tolerance: ±0.05 mm on profile, ±0.03 mm on tab pitch, flatness <=0.05 mm per 100 mm
• Minimum Feature: 0.3 mm web width, 0.5 mm slot at 1.0 mm stock, scaled with gauge
• Surface Options: bare, tin plating, nickel plating, selective silver, insulating film lamination, adhesive backing
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Drawing Review — Convert the layout to vector artwork, verify current-carrying cross-section, tab pitch and bend-line positions.
2. Alloy Selection — Pick temper and grade for conductivity and formability, then confirm sheet flatness before lamination.
3. Cleaning & Lamination — Degrease and laminate dry film resist on both faces so the outline and bend lines are protected on both sides.
4. UV Exposure — Expose front and back artwork in register, indexing half-etch bend lines to the through-cut profile.
5. Development — Develop both faces and inspect that narrow webs and slot corners are fully open before etching.
6. Two-Stage Etching — Etch the half-depth bend lines first, then continue to cut through the outline, controlling undercut by Baume, temperature and time.
7. Stripping & Plating — Strip resist, neutralize, then apply tin or nickel plating and laminate insulation where the drawing specifies.
8. Flattening & Inspection — Verify flatness, profile and plating thickness against the sample, then pack with interleaving to protect contact lands.

Core Advantages

1. Tooling-free profiles: Complex tabs, slots and stepped outlines need only a new film, so low-volume and revised designs stay economical.
2. Burr-free edges: Chemical removal leaves no roll-over burr, so insulation film and mating pads are not cut or punctured during assembly.
3. Flat contact lands: Parts leave the bath flat, keeping contact resistance low and even across parallel current paths.
4. Half-etch bend lines: Scored fold lines let a flat part fold into a three-dimensional conductor without a press brake.
5. Mixed surface finishes: Tin, nickel or selective silver plating is applied after etching, so conductivity and oxidation resistance are built in.
6. Stable joint temperature: Consistent cross-section and flatness make a custom brass busbar share current evenly, avoiding local hot spots in service.

Typical Applications

• Power distribution tabs: Multi-tab conductors in inverter and converter assemblies, typically 1.0 mm C2680 with tin plating.
• Battery module interconnects: Flat links joining cell terminals, half-etched for folding over the module edge.
• Switchgear bus links: Stepped profiles that bridge breakers and terminals without spacers or bent stampings.
• Grounding straps: Wide, thin conductors with mounting slots for chassis bonding in control cabinets.
• EV charging contacts: Plated tabs carrying high continuous current, insulated on selected faces by laminated film.
• Relay and contactor plates: Shaped current paths with integral mounting ears for electromechanical assemblies.

Design Notes & Process Considerations

1. Cross-section first: Fix thickness and minimum web width from the required ampacity before drawing the outline; never thin a web below the current path.
2. Etch compensation: State the etch factor at the chosen gauge; artwork is oversized so the finished web, not the film, meets the current rating.
3. Flatness callout: Specify flatness per 100 mm and require burr-free lands wherever the part bolts to a bus or heat sink.
4. Plating specification: Name the plating metal, thickness and whether it covers contact lands only, since tin and silver change joint resistance.
5. Bend-line depth: Give half-etch depth as a fraction of thickness, typically 40–60%, so the fold is crisp but the tab does not crack.
6. Insulation clearance: Keep laminated film back from cut edges by at least 0.5 mm so the dielectric is not undercut by the etchant.