Carbon ink, technically known as carbon-based conductive ink, is applied via screen printing and then cured to form a durable conductive layer. It is not designed as a universal solution, but rather as a specialized process for targeted applications.

Key Applications:
Carbon keypads: Ideal for devices requiring repeated pressing, such as remote controls, calculators, or appliance panels. Carbon contacts offer excellent wear resistance, tolerating hundreds of thousands of cycles.
Conductive jumpers: On single-layer PCBs, carbon ink can “bridge” across insulation areas to create circuit crossovers—an economical alternative to using double-sided boards.
Protective layers: For non-critical test pads or solder points, carbon provides limited oxidation resistance.
Unique Value Proposition:
Carbon ink delivers unmatched cost-effectiveness while providing excellent durability in specialized use cases. It is the go-to solution when the design is cost-driven and performance demands are moderate.
In PCB design and PCB Board manufacturing, surface finishing plays a decisive role in defining product performance, reliability, and final cost. For engineers and procurement managers, selecting the right process can directly influence market competitiveness. Among the many finishing options, carbon ink and electroplated gold stand out as two strategic choices. Each has its unique advantages, making the right selection critical depending on your product’s goals.

Electroplated Gold
When projects balance cost against performance, the following comparison highlights the critical differences:
| Feature | Carbon Ink (Specialized Use) | Electroplated Gold (High-Performance) |
|---|---|---|
| Cost Level | Very low, ideal for price-sensitive projects | High, best for performance-focused designs |
| Cost Up Ratio compare to OSP PCB | Double-layer: ~10–20% of board cost; Four-layer: ~5–10% |
Double-layer: ~70–100%; Four-layer: ~50–60% |
| Conductivity | Limited; suitable for signal transmission only | Excellent; extremely low resistance for high-frequency and high-speed circuits |
| Wear Resistance | Good; withstands friction, great for keypads | Superior; gold is unmatched for durability in connectors |
| Contact Stability | Adequate for low-voltage key switches | Exceptional; ensures long-term connection reliability |
| Solderability | Average, not recommended for critical joints | Excellent; provides smooth, reliable soldering surfaces |
| Typical Applications | Remote controllers, cost-saving jumpers | Gold fingers, high-reliability connectors, test pads |
Decision Guide:
Choose Carbon Ink if your product is price-sensitive, keypad-based, or focused on low-power applications.
Choose Electroplated Gold when durability, conductivity, and stable long-term performance are business-critical.
At SQPCB, we understand that process selection is not just a technical decision but a business strategy. Our strength lies in offering not only advanced PCB execution but also consultative engineering support.
Cutting-Edge Equipment for Reliability
SQPCB has invested heavily in LDI automatic exposure lines (for traces and solder mask) and inline automatic inkjet printing for legends. While this equipment requires significant capital, it ensures exceptional yield rates by eliminating defects caused by film-based processes such as dimensional shifts, misalignment, operator error, and scratches. This guarantees a consistent finish whether you choose carbon ink or gold plating.
In-House Processes for Total Control
Unlike many competitors who outsource key steps, SQPCB maintains in-house lamination, HASL (solder coating), and ENIG finishing lines. This vertical integration gives us unmatched control over both quality and delivery schedules. Clients benefit from shorter lead times and predictable, repeatable performance—essential advantages for high-stakes projects.
Our clients rely on us not only for execution but also for design-level insights and troubleshooting:
Failure Analysis Expertise: If a carbon keypad fails in testing, our team doesn’t just ship replacements—we provide root cause analysis to pinpoint whether the issue lies in process, materials, or design, helping clients avoid repeated errors.
Cost vs. Performance Balance: We can analyze your BOM and recommend where carbon ink can safely reduce cost and where gold plating is indispensable. This ensures you achieve the best cost-to-performance ratio without compromising reliability.
Priority Prototyping & Scaling: For urgent projects, SQPCB offers expedited prototypes with priority scheduling, ensuring your time-to-market goals are met without sacrificing quality.
There is no absolute winner between carbon ink and electroplated gold. The key lies in aligning the right process with your business goals. Carbon ink shines in cost-sensitive, specialized uses, while electroplated gold secures long-term reliability for high-performance designs.
With SQPCB’s advanced LDI exposure, in-house finishing lines, and consultative engineering support, you don’t need to choose blindly. We provide the expertise to help you balance performance and cost, ensuring your next product is not only competitive but also reliable in the long term.
Contact SQPCB today for a free design file evaluation—and let our experience guide your decision toward lower costs, better performance, and reliable success.