3 g and the former is the difference between the two generations of promotion in the voice and data transmission speed, it can handle images, music, video streaming and other forms of media, including web browsing, telephone meetings, e-commerce, and other information services. 3 g can achieve mobility, interactive and distributed three big business, is "anytime, anywhere" global satellite network connection.

        The biggest bright spot of 3 g is Shared 2 m bandwidth data business, it can make the world within the scope of any user using a small cheap mobile station, realize to the satellite from land to sea world three-dimensional communication network, to ensure the global roaming user anywhere, at any time to communicate with anyone, and can provide with wired telephone voice quality, provides intelligent network business, multimedia, packet radio, entertainment and broadband service.

        For the PCB industry, the rapid growth of the 3 g technology makes HDI PCB to new development to adapt to the demand of the 3 g technology. Now with 2 + c + 2 3 g communication technology is given priority to, along with the mobile phone function increases the strength and product size shrink, must make the printed circuit board design is more and more to the second-order, third-order and even more high-density interconnect horizon. Increasing mobile phone function, under the premise that the PCB area basically remain unchanged, mobile phone use HDI board has the following trends: one is the basic for the second order structure of HDI, some even need a third-order HDI structure; Second is that the space basic line width in about 75 um / 75 um, smaller 50 um / 50 um; Minimum BGA holes are 0.5 mm, soon will be 0.4 mm; Three are stacked design of blind/buried hole need plating copper fill holes or resin plug hole, to ensure the interconnection reliability and board face flat to the whole; Buried four is blind hole, hole diameter and the diameter of the welding plate is more and more small, the whole board bore laser hole density basic in 70000 ~ 120000 per square foot. As 3 g mobile phone becomes a "personal multimedia center", the third order HDI is bound to become the mainstream of 3 g mobile phone in the future.