Abstract:
This invention discloses a manufacturing method and a structure for printed circuit boards. The printed circuit boards are often used for supporting electronic components in circuit and conducting the heat from electronic components. The printed circuit board structure includes a laminated structure. The laminated structure comprises an electric conduction layer and an insulation layer. The electric conduction layer can be made of a special thermal conduction material, including a metal and a bracket structure of carbon element. The insulation layer can be made of thermal conduction material as well, combining a bracket structure of carbon element. The bracket structure of carbon element has high thermal conductivity so as to improve the heat conduction efficiency. The corresponding manufacturing method for this thermal conduction material can be made with chemical vapor deposition, physical vapor deposition, electroplating or the other materials preparation method. The bracket structure of carbon element can be coated on a surface of the metal and also can be mixed into the metal.
Abstract:
The specification discloses a cancellation circuit that suppresses electromagnetic interference in a high speed circuit using a function generator so as to utilize differential signals to cancel the magnetic field and to couple with the electric field without affecting the quality of signals. The differential signals are generated from a clock pin of the function generator, which is phase shifted by a phase shifter and passes through a microstrip antenna or a stripline antenna so as to emit electromagnetic waves with inversed phases, canceling the originally existent electromagnetic waves.
Abstract:
The invention is a cancellation circuit that suppresses electromagnetic interference in a high speed circuit, which achieves the objects of canceling the magnetic field and coupling the electric field through a differential signal under the premise of not affecting the signal quality. The differential signal is generated from the original high speed circuit using a phase shifter. Suitable phase shifters include a same-layer type, a meander type and a different-layer stacking type.
Abstract:
A multi-layer circuit board includes first, second, third, fourth and fifth insulating substrates, first, second, third and fourth signal wiring layers, a ground wiring layer, and a power wiring layer. The insulating substrates and the wiring layers are press-bonded to each other to form the circuit board with a thickness of about 1.2 mm. Each of the first and fifth insulating substrates has a thickness ranging from 4.175 to 4.725 mil. Each of the second and fourth insulating substrates has a thickness ranging from 5.7 to 6.3 mil. The third insulating substrate has a thickness ranging to 16.8 mil.