PCB is the footstone of electronics industry as all electronic circuits need PCB. At present, PCB industry has been mature, with limited or declining growth rate. In 2008-2009, the output value of PCB industry fell due to fierce price competition. In 2010, electronics industry started to rebound, but PCB industry only grew by 10.5%. In 2011, the growth rate of PCB industry is expected to be only 5.1%.

The mode of 1 HDI+2 traditional circuit boards+1 HDI is adopted for internal circuit boards of ordinary mobile phones, with the traditional boards sandwiched between two HDIs.

2+2+2and 3+2+3 design modes are adopted for intermediate and high-end smart phones, with 4 layers and 6 layers of HDI respectively. In addition, the mode of 1 HDI+8 traditional circuit boards+1 HDI is applied in iPad1, with 2 layers of HDI; the design mode of 3+4+3 is applied in iPad2, with 6 layers of HDI, i.e. any layer of HDI, thus reducing the thickness to 0.88cm (The thickness of iPad1 is 1.34cm).

The thickness of new iPad is 1/3 of that of the old ones, as the HDI has changed from multilayer PCB to any layer PCB with intensive holes on. However, the holes on any layer must be punched via laser but not machine. In the future, iPhone5 will be lighter and thinner, even thinner than iPad2.

    There are four iPad2 suppliers in the world, including Tripod, a senior supplier of HDI main boards in Taiwan, the USA’s TTM, and Japan’s IBIDEN and MEIKO. Other alternative suppliers are all from Taiwan, including Nan Ya Printed Circuit Board Corporation, Gold Circuit Electronics, Compeq and Unimicron