Short answer: solder tabs are small stamped features that provide a solderable or weldable surface for electrical connections. They are commonly copper or brass with tin, silver, or gold plating, designed to accept a soldered wire, PCB pad, or welded busbar. The critical RFQ factors are material conductivity, plating thickness, burr direction, tab geometry, and solderability test requirements.
This guide is for engineers and purchasers sourcing stamped solder tabs, weld tabs, PCB solder terminals, battery tabs, relay tabs, and busbar connection tabs. These small parts affect assembly yield and reliability, especially in hand-soldered or wave-soldered processes.
Yonnee drawings with material, plating, thickness, tab dimensions, and assembly method through the RFQ form. For related battery and busbar parts, see EV battery tëggin parts and busbars and the copper busbar tëggin RFQ guide.
Common solder tab applications
- Battery pack interconnect tabs for spot welding or soldering to cell terminals.
- PCB solder terminals for through-hole or surface-mount wire connections.
- Relay and contactor tabs for soldered coil or power connections.
- Busbar connection tabs for bolted or soldered power distribution links.
- Capacitor and sensor tabs for welded or soldered internal connections.
- Shield grounding tabs for EMI cans and connector shells.
For precision small parts, see precision small tëggin metal ci matris for electronics.
Materials for solder tabs
Material choice depends on solderability, current capacity, mechanical strength, and cost. Copper has the best conductivity but needs protection from oxidation. Brass is cheaper but less conductive. Nickel is used where corrosion resistance matters more than conductivity.
| Material | Conductivity | Solderability | Typical plating |
|---|---|---|---|
| Copper (C110, C102) | High (100% IACS) | Good with flux | Tin, silver, or none |
| Brass (C260, C268) | Moderate (28% IACS) | Good | Tin, nickel, or silver |
| Phosphor bronze (C510, C521) | Moderate (15% IACS) | Good | Tin or silver |
| Nickel 200/201 | Low (25% IACS) | Fair, needs active flux | Gold or none |
| Nickel-plated steel | Low | Good with flux | Nickel pre-plated on strip |
| Beryllium copper | Moderate (20-25% IACS) | Good | Tin or silver |
For more on jokkoo materials, see phosphor bronze and beryllium copper jokkoo tëggin.
Plating and solderability
Solder tabs are usually plated to improve solder wetting, prevent oxidation during storage, and meet RoHS or REACH requirements. Common plating options include:
- Tin plating — most common for copper tabs. Matte tin preferred for soldering (bright tin has higher risk of whiskers). 2 to 8 microns typical.
- Silver plating — for high-power connections where tin may melt. 2 to 5 microns typical.
- Gold plating — for critical signal connections where corrosion resistance and low jokkoo resistance matter. 0.5 to 2 microns over nickel underplate.
- Nickel underplate — often used beneath silver or gold to prevent copper migration. 1 to 3 microns typical.
Plating must cover the tab surface without bridging into adjacent features or creating buildup on edges. For more on finishing, see tëggin metal ci matris plating and passivation RFQ guide.
Tab design considerations
Burr direction. On solder tabs, the burr should be on the non-solder side or specified to avoid interfering with solder flow. If the tab is used for resistance welding, a burr on the weld surface can cause inconsistent weld nuggets. Specify burr direction and maximum burr height on the drawing.
Tab thickness. Thicker tabs carry more current but take longer to heat during soldering. For hand-soldered connections, 0.3 to 0.8 mm is common. For wave or reflow soldering, 0.2 to 0.5 mm is typical. For welded tabs, thickness depends on the weld schedule and material stackup. For related design rules, see tëggin metal ci matris part design guide.
Solder hole or slot. A hole, slot, or pierce-through feature in the tab can improve solder joint strength by providing a mechanical lock and additional surface for solder wetting. The hole should be placed within the solder zone without weakening the structural connection between the tab and the rest of the part.
Tab orientation after forming. If the tab is bent relative to the main body, the bend axis, radius, and angle must be clearly dimensioned. Tabs that must align with a PCB pad or cell terminal should include true-position tolerances for both the body and the tab tip.
Tolerances
- Tab width: ±0.10 mm typical for precision tooling.
- Tab position relative to datum: ±0.13 mm.
- Tab thickness: ±0.03 mm for precision, ±0.05 mm commercial (controlled by material gauge tolerance).
- Bend angle: ±1 degree.
- Solder hole position: ±0.08 mm for precision.
- Burr height: 0.05 mm max typical, 0.03 mm max for tight requirements.
See tëggin metal ci matris tolerances guide for detailed tolerance classes.
RFQ checklist for solder tabs
- Drawing with flat pattern and formed view showing tab geometry, hole pattern, and bend details.
- Material: grade, temper, thickness, and plating (material + plating thickness).
- Annual volume and order quantity.
- Assembly method: hand solder, wave, reflow, resistance weld, or laser weld. Each method has different tab thickness and material requirements.
- Solderability test requirement: edge dip, wetting balance, or customer-specific standard.
- Burr direction and max burr height.
- Packaging: tape and reel for automated assembly, or bulk/trays.
- Current rating if applicable, to confirm tab cross-section and plating meet the ampacity.
Submit your solder tab drawings through the RFQ form. For RFQ preparation guidance, see the tëggin metal ci matris RFQ checklist.