Multi-layered printed wiring board

A multi-layered printed wiring board comprising:

• at least one power supply layer;
• at least one around layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers,
• said at least one power supply layer being provided thereon with a circuit in the form of branch wirings for imparting impedance thereto,
• wherein said at least one power supply layer is interposed between ground layers with said insulators arranged on either side of said power supply layer sandwiched between said power supply layer and each of said ground layers.

A multi-layered printed wiring board comprising:

• at least one power supply layer;
• at least one ground layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers,
• said at least one power supply layer being provided thereon with a circuit in the form of branch wirings for imparting impedance thereto,
• wherein said impedance imparting circuit is composed of line patterns providing a greater inductance in limited regions than an inductance to be generated in other regions.

A multi-layered printed wiring board comprising:

• at least one power supply layer;
• at least one around layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers,
• said at least one power supply layer being provided thereon with a circuit in the form of branch wirings for imparting impedance thereto,
• wherein said impedance imparting circuit is composed of at least one of winding, intersecting and spiral line patterns.

A multi-layered printed wiring board comprising:

• at least one power supply layer;
• at least one ground layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers,
• said at least one power supply layer being provided thereon with a circuit in the form of branch wirings for imparting impedance thereto
• wherein insulators sandwiching said power supply layer therebetween contain magnetic substance therein,
• wherein said magnetic substance containing insulators have magnetic permeability having both a real number part which is not decreased in a predetermined frequency band and an imaginary number part which has uniform characteristics in said predetermined frequency band.

A multi-layered printed wiring board comprising:

• at least one power supply layer;
• at least one ground layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers,
• said at least one power supply layer being provided thereon with a circuit in the form of branch wirings for imparting impedance thereto
• wherein insulators sandwiching said power supply layer therebetween contain magnetic substance therein,
• wherein said insulators contain magnetic substance having hysteresis characteristic which is not saturated, but excited with a dc current running through circuits mounted on said multi-layered printed wiring board and operated independently with each other.

A multi-layered printed wiring board comprising:

• at least one power supply layer;
• at least one ground layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers,
• said at least one power supply layer being provided thereon with a circuit in the form of branch wirings for imparting impedance thereto
• wherein insulators sandwiching said power supply layer therebetween contain magnetic substance therein,
• wherein said insulators sandwiching said at least one power supply layer therebetween is made of one of a sintered ferrite and a mixture of ferrite powder and resin.

A multi-layered printed wiring board comprising:

• at least one power supply layer;
• at least one around layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers,
• said at least one power supply layer being provided thereon with a circuit in the form of branch wirings for imparting impedance thereto
• wherein insulators sandwiching said power supply layer therebetween contain magnetic substance therein,
• wherein said insulators sandwiching said at least one power supply layer therebetween is made of NiZn family sintered ferrite.

A multi-layered printed wiring board comprising:

• at least one power supply layer including main wirings for distributing a dc current entirely to said printed wiring board with a dc voltage drop being depressed, and branch wirings for enhancing high frequency impedance to isolate circuits in terms of high frequency, which circuits are mounted on said multi-layered printed wiring board and operated independently with each other;
• at least one ground layer;
• at least one signal layer;
• and
• insulators sandwiched between said layers.