Traditional HDI circuit boards are used for portable goods and semiconductor packaged goods. 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 to use the materials in the system to meet the performance indicators of the physical device, for example, the design of the circuit board will be affected by crosstalk, structure, and signal characteristics. For those complex, multiple-laminated circuit boards, buried vias and blind vias are simple structures. By comparing with material stability, board surface treatment and design rules, assembly process problems can be identified in circuit testing.
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 pioneering role in this area and have established many standards. Therefore, the demand for products has also changed 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 network industries have not yet felt the strong pressure of HDI technology, but due to the increase in component density, they will soon face this pressure and begin the development of HDI technology. The advantages of using HDI boards in flip-chip packaging are obvious because it reduces the pitch and increases the number of I/Os.