Printed wiring boards trends

With the conventional technology, ICs are mounted individually in plastic or ceramic single-chip packages (SCPs), such as dual-in-line packages (DIPs) or chip carriers, and the SCPs are interconnected on printed wiring boards (PWBs). The number of pins on SCPs has increased significantly, and line widths on PWBs, like IC feature sizes, have followed a historical downward trend (2). However, the basic SCP-on-PWB approach has remained predominant. 

Due to the ongoing miniaturization trend of electronic devices and for meeting some critical application requirements, several techniques and approaches for improving the thermal stability and flame retardancy of the epoxy resins have been employed. Actually, all the modern-day electronic devices contain at least one printed wired board to support... 

Since the invention of printed wiring technology by Dr. Paul Eisner in 1936, several methods and processes have been developed for manufacturing printed wiring board (PWBs) of various types. Most of these have not changed significantly over the years however, some specific trends continue to exert major influences on the types of PWBs required and the processes that create them ... 

These trends have led to the larger use of nonorganic base substrates, such as aluminum and soft iron. In addition, alternate ways to create boards have been developed. These will be discussed in this chapter, along with the traditional board structures and processes. The terms printed wiring board, PWB, and board will be used synonymously. Also, the words laminate, substrate, and panel will be used interchangeably. 

In addition to wire harness connectors, printed circuit board-attached connectors, for automotive or electronic applications, also benefit from many of SPS s performance characteristics, including low viscosity, which helps to fill thin walls and heat resistance to maintain dimensional stability through lead-free reflow soldering operations (see Table 15.2). The trend toward miniaturization in automotive electronic control modules has increased the need for compact surface mount connector technology, as opposed to bulkier through-hole and wave-soldered alternatives. 

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