Carbon ink PCBs are a special type of printed circuit board (PCB) made using thermosetting carbon paste (i.e., carbon ink) with excellent conductivity. The carbon ink is applied to the PCB surface using a screen-printing process and, after curing, forms a thick film protective layer. This carbon layer is both conductive and has a certain resistance value, which is why carbon ink PCBs are also known as Carbon Thick Film PCBs or Printed Carbon Resistors (PCR).

Functions of Carbon Ink

In PCB manufacturing, the primary function of carbon ink is to connect adjacent copper areas, forming conductive pathways between circuit traces or between traces and components. Additionally, the cured carbon ink layer provides a protective coating that not only ensures conductivity but also meets specific resistance requirements. This enables the circuit to achieve both electrical conductivity and impedance adjustment functionalities.

Precautions for Printing Carbon Ink

 1. Ensure the printing machine operates with stable temperature and pressure.

 2. Keep the printing nozzle clean and free of impurities.

 3. Control the thickness of the carbon ink layer to avoid short circuits between conductive layers.

 4. Ensure precise printing alignment to guarantee reliable circuit connections.

 5. After printing, ensure the carbon ink is completely dry to prevent issues in subsequent processes and maintain circuit performance.

 6. Inspect the printed output to ensure it is accurate and free of defects.

Main Applications of Carbon Ink PCBs

Carbon ink PCBs are primarily used in areas such as keypads, where conductivity and wear resistance are required. They were commonly used in products like TV remote controls, telephones, children's toys, and computers for keypad positions. Today, they are also utilized in products like elevators.