However, these calculations work best when no overlapping features are obscuring the QFN, such as if it were on a single-sided board
. The reality, as seen in Figure 1, is you are usually not so lucky!
The test board is a single-sided board
with all the SMA (subminiature version A) connectors located on the top layer (TABLE 2).
Mitsubishi Gas Chemical's PCB business consists of Japan Circuit Industry (JCI) and Tai Hong Circuit Industry in Taiwan, which has a single-sided board
manufacturing plant in Dongguan, China.
The pad dimensions on a single-sided board
are often larger than those on a PCB with PTHs in order to provide sufficient adhesive strength between the base material and copper cladding to which joints are soldered.
Turkey seems to have cornered the local market on TV manufacturing, with three single-sided board
makers of decent size.
Breakdown of Taiwanese PCB technology distribution for 2002 and 2004 CATEGORY 2002 2004 Single-sided board
3% 2% Double-sided board 8% 7% Multilayer board 68% 57% Flex 8% 15% IC substrate 13% 19% Source: TPCA and NTI
We feel that the single-sided board
is a product onto itself.
Mexico once boasted of making more than 30 million TVs, but the manufacture of small sets has shifted to China, stagnating its single-sided board
Components are spread out on single-sided boards
. Manufacturers also need to emphasize flexible form factors.
FPCs include single-sided boards
(single-layer circuits), double-sided boards (two layers of circuits with insulating film in between), or multilayer boards (three or more layers of circuits) (FIGURE 1).
The designs feature low component count and leverage simple magnetics and single-sided boards
yielding power densities of 14.2 W/1n3.