There are five main driving factors for the development of high-performance HDI circuit board products, which affect each other. The factors considered in this type of circuit design are: circuit components (signal integrity), sheet metal, stacking, and design standards. Although circuits are crucial for considering signal integrity, cost factors cannot be ignored. Based on this, it is important to consider a compromise solution during the operation process.

　　The performance of the actual circuit varies with the rise time of the signal. These large area, high-performance HDI circuit boards handle high-speed computer buses or telecommunications signals, and are very sensitive to noise and signal reflection. The following five basic characteristics can describe signal sensitivity: characteristic impedance, low-voltage differential signal (LVDS), signal attenuation, noise sensitivity, and crosstalk interference.

　　The characteristic impedance of single ended microstrip lines, striplines, coplanar, and audio signals is determined by the dielectric constant of the substrate, plate thickness, stacking structure characteristics, and design criteria. The loss of data signals is the result of the dielectric loss of raw materials, design rules, and line length. Various types of noise, including crosstalk, such as planar rebound noise, switching noise, power spikes, etc., are the result of power coupling, stratigraphy, design rules, and raw material characteristics determined by the laminated structure of the board.

　　Reducing inductance is one of the main goals for improving the signal integrity of high-speed signal boards. SMT pads with low inductance are typically those without wiring or VIP (via in PAD) processes.