With the gradual development of electronic products towards short, small, light, and thin, FPC soft boards are becoming increasingly popular among design engineers, and the demand is constantly increasing. Some soft boards require non adhesive substrates to be produced in order to ensure the bending quality and frequency of the product. So, how to distinguish between adhesive substrates and non adhesive substrates? Below, the editor will explain in detail.

How can FPC manufacturers distinguish between FPC with adhesive substrate and non adhesive substrate

FPC (Flexible Circuit Board) mainly uses polyimide (PI) copper-clad laminate (FCCL) or polyester (PET) copper-clad laminate.

Flexible copper foil substrates (FCCL) are divided into two categories: traditional three-layer flexible board substrates with adhesive and new two-layer flexible board substrates without adhesive.

It is composed of flexible insulation base film and metal foil, and is composed of three different materials: copper foil, thin film, and adhesive. The flexible copper-clad laminate is called three-layer flexible copper-clad laminate (3L-FCCL), which is also known as adhesive substrate. Simply put, it means coating the PI film with adhesive and then bonding it to the copper foil.

The adhesive free flexible copper-clad laminate is called two-layer flexible copper-clad laminate (2L-FCCL), which is also known as adhesive free substrate. Because the manufacturing methods of these two types of flexible copper foil substrates are different, the material properties of the two types of substrates are also different.

There are two methods for adhesive free flexible copper-clad laminates. One is to use PI film as a carrier and immerse copper foil on its surface. The other method is to use copper foil as a carrier, coat liquid PI on the surface of the copper foil, and then cure it.

The adhesive free substrate is relatively thin, and its surface cannot be distinguished by the naked eye. Only by performing slice analysis can it be distinguished.

The above is the information compiled by the editor on how to distinguish between adhesive and non adhesive substrates. We hope it is helpful to everyone. If there are still any unclear areas, please contact QQ, WeChat or phone on the right. We have professional personnel to serve you.