There are several brands of raw materials for FR-4, including:
Isola: Isola Group is a leading global supplier of printed circuit board materials, offering various types of FR-4 materials such as IS410, IS620, and more.
Panasonic: Panasonic Corporation is a renowned global electronics manufacturer that also provides FR-4 circuit board materials.
Shengyi Technology: Shengyi Technology Co., Ltd. is one of the major PCB material suppliers in China, offering a range of FR-4 material series like S1000, S1170, and others.
ITEQ: ITEQ Corporation is a PCB material supplier headquartered in the Netherlands, providing FR-4 materials globally, such as IT-180A, IT-158, and more.
These brands represent a portion of the market, and there are many other companies that offer various types of FR-4 materials. When selecting materials, it is advisable to evaluate them based on specific requirements and engage in further discussions and consultations with suppliers.