Traditional HDI circuit boards are used for portable products and semiconductor package products. The third category of HDI applications: high-speed industrial system applications. The difference between this type of printed circuit board used in telecommunications and computer systems and the above two types of circuit boards is that the PCB board size is large and the focus is on electrical performance, while the packaging of PBGA and CCGA is very complicated.
How the materials in the system are used to meet the performance specifications of the physical device, for example, the design of the circuit board can be affected by crosstalk, structure and signal characteristics. For those complex, multi-lamination circuit boards, buried and blind vias are simple structures. Assembly process issues can be identified during circuit testing by comparison with material stability, board surface treatment, and design rules.
The classification of HDI products is determined by the latest development of HDI and the strong demand for HDI products. Mobile companies and their suppliers have played a role in this area and have developed many standards. Therefore, the demand for products also changes the technical limitations of mass production, making the price more affordable. Japan's consumer industry has taken the lead in HDI products. The computer and networking industries have not yet felt the strong pressure of HDI technology; but due to the increase of component density, they will soon face this pressure and start the development of HDI technology. The advantages of using HDI boards in flip-chip packaging are obvious, as it reduces pitch and increases I/O count.
