Grade B epoxy fiberglass laminate (commonly known as G10) and FR-4 are two materials widely used in various industries and have excellent electrical and mechanical properties. Although they look similar, there are some key differences between the two.

G10 is a high-voltage fiberglass laminate known for its high strength, low moisture absorption and excellent electrical insulation properties. Commonly used in applications requiring high mechanical strength and good electrical insulation, such as electrically insulating panels, terminal blocks and structural components in electronic equipment.

FR-4, on the other hand, is a flame retardant grade of G10. It is made of fiberglass woven cloth impregnated with epoxy resin adhesive and has excellent electrical insulation properties and flame retardancy. FR-4 is widely used in printed circuit boards (PCBs) and other electronic applications that require flame retardancy and high mechanical strength.

The main difference between G10 and FR-4 is their flame retardant properties. Although G10 has high mechanical strength and electrical insulation, it is not inherently flame retardant. In contrast, FR-4 is specifically designed to be flame retardant and self-extinguishing, making it suitable for applications where fire safety is a concern.

Another difference is the color. G10 is usually available in a variety of colors, while FR-4 is usually light green due to the presence of flame retardant additives.

In terms of performance, both G10 and FR-4 have excellent dimensional stability, high mechanical strength and good electrical insulation properties. However, when it comes to applications with stringent requirements for flame retardancy, FR-4 is the first choice.

In summary, while G10 and FR-4 share many similarities in composition and performance, the main differences are in flame retardant properties and color. Understanding these differences is critical to selecting the right material for a specific application, ensuring optimal performance and safety.