In the process of producing multi-layer high-frequency mixed pressure boards, many people are curious about why high-frequency board factories do not use single-core board fabrication. To understand this question, let's first have a basic understanding of how multi-layer high-frequency mixed pressure boards are typically manufactured in the PCB industry. In the following explanation by the team at BSI Circuit (a high-frequency board factory), we'll explore why multi-layer high-frequency mixed pressure boards cannot be fabricated using single-core boards.
As shown in Figure (2), the structure commonly used for multi-layer high-frequency boards and mixed pressure boards involves utilizing two core boards with an intermediate PP adhesive sheet (referred to as a pseudo six-layer structure). However, getting back to the main point, for our multi-layer high-frequency mixed pressure boards, when precise frequency information is required or when there are specific demands on the dielectric material between L1 and L2 or between L3 and L4, such as using high-frequency materials or having strict requirements on dielectric thickness ratios, it becomes necessary to use a single core board for either L1 and L2 or L3 and L4 to meet the requirements.
From this perspective, it's evident that multi-layer high-frequency mixed pressure boards cannot be fabricated using single-core boards.
