HDI Technologies

A second valnable feature of the chart in Fig. 2.2 is the area identified as the region of advanced technologies. This is where calculations and data have shown that it is necessary to have an HDI structure. Therefore, this is the barrier, or wall of HDI on one side it is most cost effective to use traditional PWB technologies on the other side it becomes cost effective to use HDI technologies. Continuing beyond this point, HDI becomes necessary. 

Structure This factor determines the number of signal layers and the combination of through and buried vias that permit interconnection between layers and the complex blind, stacked, and variable depth vias available in high-density interconnection (HDI) technologies. 

FIGURE 23.1 The HDI technologies in use today are made up of three factors the dielectric materials, the methods of IVH formation, and the method of metallization of those z-axis via connections. In recent years up until now, 21 different HDI processes have been used. 

ADVANCED HIGH-DENSITY INTERCONNECTION (HDI) TECHNOLOGIES 23.9 Conventional lamination with pre >reg /foil or RCC Laser dril... 

MSF. Shinko of Japan developed the MSF HDI technology. It utilizes laser-drilled RCC materials and vias filled with a conductive paste. After testing, these are laminated into the parallel build-up structure. Figure 23.24 shows the typical manufacturing sequence for this HDI technology. 

Neo-Manhattan Bump Interconnect (NMBI). The NMBI technology is one of the newest of the Japanese HDI technologies. It might be considered a third-generation ... 

HDI technology after technologies as ALIVH is considered a second-generation HDI technology. NMBI was pioneered by North Corporation of Japan. 

HDI technology creates small blind microvias that are plated to provide interconnects to buried layers of circuitry. These small holes can either be coated with solder mask or filled and plated over so that the real estate of the hole can be utilized for a circuit or a component mounting pad (via-in-pad). 

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