Abstract:
A multi-layer circuit board includes first, second, third, fourth, fifth, sixth and seventh insulating substrates; first, second, third, fourth and fifth signal wiring layers; first and second ground wiring layers; and a power wiring layer. Each of the first and seventh insulating substrates has a thickness ranging from 2.5 to 6.5 mil. Each of the second, fourth and sixth insulating substrates has a thickness ranging from 3 to 9 mil. Each of the third and fifth insulating substrates has a thickness ranging from 3 to 23 mil. The first signal wiring layer has a first resistance with respect to the first ground wiring layer. The second signal wiring layer has a second resistance with respect to the first ground wiring layer and the power wiring layer. The third signal wiring layer has a third resistance with respect to the first ground wiring layer and the power wiring layer. The fourth signal wiring layer has a fourth resistance with respect to the second ground wiring layer and the power wiring layer. The fifth signal wiring layer has a fifth resistance with respect to the second ground wiring layer. The first, second, third, fourth and fifth resistances are within the range of 49.5 to 60.5 ohms.
Abstract:
In order to reduce electromagnetic inductive interference due to power source current, in a multi-layer printed board on which a multiplicity of high-speed and high-frequency circuit elements are mounted, a multi-layer printed board has a construction such that on both upper and lower sides of a power source layer 1 provided with power source wiring 6, are laminated ground layers 2 via respective first insulating material layers 4, and on one or both of the upper and lower sides of these is laminated a signal layer 3 provided with signal wiring, via a second insulating material layer 5.
Abstract:
A multilayer wiring board of this invention includes first and second power source patterns of a first potential and a third power source pattern of a second potential. A wiring pattern formed in a signal wiring layer is positioned between the first power source pattern of the first potential and the third power source pattern of the second potential. A hole is connected to the wiring pattern and passes through the first and second power source patterns of the first potential and the third power source pattern of the second potential. A first gap is formed between the first power source pattern of the first potential and the hole. A second gap is formed between the second power source pattern of the first potential and the through hole and is larger than the first gap. Another multilayer wiring board of the present invention includes a top surface, a signal wiring provided on the top surface, a first power source pattern formed in a first power source layer in a position which is the closest to the signal wiring, a second power source pattern formed in a second power source layer and a hole which is connected to the signal wiring and passes through the first and second power source patterns. A first gap is formed between the first power source pattern and the through hole. A second gap is formed between the second power source pattern and the through hole and is larger than the first gap.
Abstract:
A multilayer printed circuit board and a corresponding fabrication method are disclosed, which circuit board achieves a relatively high degree of wiring density and a relatively high degree of wiring design freedom. These advantages are obtained in the inventive printed circuit board by electrically connecting power conductors or ground conductors using through holes. On the other hand, signal conductors in any two adjacent signal wiring layers are electrically connected using via holes extending only through an intervening electrically insulating layer. Preferably, the electrically insulating layer is a layer of photosensitive resin and the via holes are formed using conventional photolithographic techniques.
Abstract:
A circuit board includes a circuit-conductor layer, a ground layer and a power source layer superposed in a multilayer form through dielectric layers therebetween, A heat conduction through inside of the circuit board is enhanced so that circuit chips mounted on the circuit board can be cooled down to a level capable of operating normally, The circuit board can be formed to be compact, In order to enhance the heat transfer in the circuit board, at least one of the ground layer and power source layer is formed in a multilayer manner, It is preferable to form these layers at a thickness larger than that of the circuit-conductor layer, Further, preferably, the pin of the chip mounted on the board and at least one of the ground layer and power supply layer are connected to each other in such a manner as to enhance the heat conduction.
Abstract:
A printed circuit board backpanel uses stripline construction to allow emitter coupled logic. (ECL) signals and transistor-transistor logic (TTL) signals on the same signal layer, while providing electromagnetic interference (EMI) emission control.
Abstract:
A multilayer wiring board structure includes a plurality of conductor layers and insulation layers interleaved between each ones of the conductor layers. The conductor layers includes power (or ground) line layers and signal line layers, and one type of insulation layer having lower relative permittivity and another type of insulation layer having higher relative permittivity is used between power (ground) line layers interposed by signal line layer(s).
Abstract:
A multilayer printed circuit board for TTL logic components provides an approximate 100 ohm characteristic impedance between external microstrip signal lines and internal ground and voltage planes. The addition of two internal microstrip signal plane lines permits a much greater interconnectability capability and also saves a large percentage of spatial area for component mounting while still maintaining the 100 ohm impedance characteristic.
Abstract:
A thick film multilayer substrate using a green ceramic sheet is constructed such that at least three conductor layers and at least two dielectric layers are alternately arranged in turn on the green ceramic sheet substrate, a power supply line being formed in the second conductor layer and thus interposed between the first and third conductor layers in which grounded conductors are formed.