zubair
Member level 1
Abstract
Advances in device technology are driving the need for
circuit boards capable of carrying digital signals at frequencies
greater than 1 GHz. While in recent years there have been
significant achievements in various aspects of boardmanufacturing
processes, little has been done to improve the
interconnections between non-adjacent layers in large highperformance
multi-layer boards. Standard any-layer to anylayer
interconnection techniques of drilling and plating
through holes (PTH) remain relatively unchanged since they
were first introduced in the 1960’s. The main drawback of a
PTH is that it creates an electrical discontinuity in the stripline
structure which guides a signal on the PCB layers. Whereas
reducing the diameter of the PTH minimizes this discontinuity,
the further improvements of the PTH performance are limited
by fundamental scaling restrictions of currently available
manufacturing processes. As board bandwidth requirements
are expected to more than double in the next decade, so too
will the performance required of layer-to-layer
interconnections, outstripping today’s capabilities.
The main goal of this paper is to demonstrate a novel
concept of an any-layer to any-layer interconnection technique
in a large high-performance multi-layer board. The proposed
technique introduces a true impedance-controlled wave-guide
structure for interconnections between various layers, thus
significantly reducing and even wholly eliminating the signal
discontinuity. In addition, this structure offers good isolation
and density characteristics, which enable routing more signals
through a multi-layer PCB using the same number of layers.
Moreover, the electrical performance of this structure is
entirely independent of the hole diameter. The results of our
theoretical and experimental studies of the signal performance
of this structure show that the proposed technique enables one
to improve the performance of circuit boards carrying digital
signals at multi-gigabit speeds.
Advances in device technology are driving the need for
circuit boards capable of carrying digital signals at frequencies
greater than 1 GHz. While in recent years there have been
significant achievements in various aspects of boardmanufacturing
processes, little has been done to improve the
interconnections between non-adjacent layers in large highperformance
multi-layer boards. Standard any-layer to anylayer
interconnection techniques of drilling and plating
through holes (PTH) remain relatively unchanged since they
were first introduced in the 1960’s. The main drawback of a
PTH is that it creates an electrical discontinuity in the stripline
structure which guides a signal on the PCB layers. Whereas
reducing the diameter of the PTH minimizes this discontinuity,
the further improvements of the PTH performance are limited
by fundamental scaling restrictions of currently available
manufacturing processes. As board bandwidth requirements
are expected to more than double in the next decade, so too
will the performance required of layer-to-layer
interconnections, outstripping today’s capabilities.
The main goal of this paper is to demonstrate a novel
concept of an any-layer to any-layer interconnection technique
in a large high-performance multi-layer board. The proposed
technique introduces a true impedance-controlled wave-guide
structure for interconnections between various layers, thus
significantly reducing and even wholly eliminating the signal
discontinuity. In addition, this structure offers good isolation
and density characteristics, which enable routing more signals
through a multi-layer PCB using the same number of layers.
Moreover, the electrical performance of this structure is
entirely independent of the hole diameter. The results of our
theoretical and experimental studies of the signal performance
of this structure show that the proposed technique enables one
to improve the performance of circuit boards carrying digital
signals at multi-gigabit speeds.