Rigid PCBs

Printed circuit boards have undergone a variety of changes since their invention in 1903. Today, you will find manufacturers offering various types of printed circuit boards. However, the first PCB type that was created was the rigid circuit board.

What does a Rigid PCB Consist of?

A rigid printed circuit board consists of a bare board with FR-4 glass epoxy panels. These panels are used as the primary insulation. Copper foils are laminated onto the sides of the FR-4 panel. Interconnecting circuits are etched into the copper layers. A photo resist is printed onto the core panels.

The rigid PCB can be designed in single or multiple layers. The layers of a rigid PCB can be increased up to 14 layers easily. The multiple layers allows for the creation of complex circuitry. Due to the number of FR-4 panels in each layer, these PCBs are known to be quite dense.

Materials

A range of materials can be used to create these products. Generally, the most popular materials used in the rigid PCB manufacturing process includes:

• Teflon
• Polyimide
• Aluminum
• Gold
• ENIG

Quality Compliance

Rigid PCBs are designed in accordance to regulations set down by various organizations. The PCB needs to adhere to regulations of a specific standard, depending on the industry and the application it will be used in. Many PCB manufacturers ensure that their PCB designs adhere to the following certifications based on the industry they cater to:

• UL (Underwriters Laboratories)
• ISO-9001 (International Organization for Standardization)
• AS 9100 (Aerospace Certification)
• IPC-6012/6013 (Institute of Printed Circuit Boards)
• MIL-PRF-31032 (Military Performance)
• MIL-PRF-50884 (Military Performance)

Despite the invention and use of flexible, and rigid flex circuit boards, rigid PCBs continue to be an important and popular circuit board for industrial applications.