资料介绍
PCB Stack-Up -- Part 4 - Eight-Layer Boards
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PCB Stack-Up
Part 4. Eight-Layer Boards
An eight-layer board can be used to add two more routing layers or to
improve EMC performance by adding two more planes. Although we see
examples of both cases, I would say that the majority of eight layer board
stack-ups are used to improve EMC performance rather than add additional
routing layers. The percentage increase in cost of an eight-layer board
over a six-layer board is less than the percentage increase in going from
four to six layers, hence making it easier to justify the cost increase for
improved EMC performance. Therefore, most eight-layer boards (and all the
ones that we will concentrate on here) consist of four wiring layers and
four planes.
An eight-layer board provides us, for the first ti