Printed circuit board for prevention of unintentional electromagnetic interference

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• and
• (c) a multi-layered structure disposed at a marginal end of said printed circuit board between said ground layer and said power-supplying layer, said multi-layered structure having a function of disallowing d.c. current communication between said ground layer and said power-supplying layer, said multi-layered structure comprising a compound layer and a dielectric layer both of which are alternately deposited, said compound layer comprising a resistive layer, and metal layers sandwiching said resistive layer therebetween.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• (c) a resistive film extending from an upper surface to a lower surface through a sidewall of said printed circuit board;
• (d) pads formed on said upper and lower surfaces of said printed circuit board;
• and
• (e) a capacitor formed on one of said upper and lower surfaces of said printed circuit board,
• said ground layer and said power-supplying layer being in electrical communication with each of said pads through via-holes at a marginal end of said printed circuit board,
• said resistive film being in electrical communication with one of said pads through said capacitor, and being in direct electrical communication with the other of said pads.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• (c) a resistor formed on a sidewall of said printed circuit board;
• (d) pads formed on upper and lower surfaces of said printed circuit board;
• and
• (e) a capacitor formed on one of said upper and lower surfaces of said printed circuit board,
• said ground layer and said power-supplying layer being in electrical communication with each of said pads through via-holes at a marginal end of said printed circuit board,
• said resistor being in electrical communication with one of said pads through said capacitor, and being in direct electrical communication with the other of said pads.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• (c) two pads formed on a common surface among upper and lower surfaces of said printed circuit board;
• (d) a resistor disposed on said common surface of said printed circuit board;
• and
• (e) a capacitor formed on said common surface of said printed circuit board,
• said ground layer and said power-supplying layer being in electrical communication with each of said pads through via-holes at a marginal end of said printed circuit board,
• said resistor and said capacitor being electrically connected in series with each other between said pads.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another, said power-supplying layer comprising a plurality of sections;
• (c) two pads formed on a common surface among upper and lower surfaces of said printed circuit board for each of said sections of said power-supplying layer;
• (d) a resistor disposed on said common surface of said printed circuit board for each of said sections of said power-supplying layer;
• and
• (e) a capacitor formed on said common surface of said printed circuit board for each of said sections of said power-supplying layer,
• said ground layer and said power-supplying layer being in electrical communication with each of said pads through via-holes at a marginal end of each of said sections,
• said resistor and said capacitor being electrically connected in series with each other between said pads.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• (c) a plurality of pad-pairs formed on a common surface among upper and lower surfaces of said printed circuit board at a marginal end thereof, adjacent pad-pairs being spaced away from each other by a distance W defined as a half or smaller of a wavelength associated with an upper limit frequency within a frequency band to be suppressed;
• (d) resistors disposed on said common surface of said printed circuit board;
• and
• (e) capacitors formed on said common surface of said printed circuit board,
• each of said ground layer and said power-supplying layer being in electrical communication with a pad in each of said pad-pairs through a via-hole at a marginal end of said printed circuit board,
• each of said resistors and each of said capacitors being electrically connected in series with each other between pads in each of said pad-pairs.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another, said power-supplying layer comprising a plurality of sections;
• (c) a plurality of pad-pairs formed on a common surface among upper and lower surfaces of said printed circuit board for each of said sections of said power-supplying layer, adjacent pad-pairs being spaced away from each other by a distance W defined as a half or smaller of a wavelength associated with an upper limit frequency within a frequency band to be suppressed;
• (d) resistors disposed on said common surface of said printed circuit board for each of said sections of said power-supplying layer;
• and
• (e) capacitors formed on said common surface of said printed circuit board for each of said sections of said power-supplying layer,
• each of said ground layer and said power-supplying layer being in electrical communication with a pad in each of said pad-pairs through a via-hole at a marginal end of each of said sections,
• each of said resistors and each of said capacitors being electrically connected in series with each other between pads in each of said pad-pairs.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• and
• (c) a magnetic layer formed in said dielectric layer sandwiched between said ground layer and said power-supplying layer, said magnetic layer including a magnetic loss and having a center located at about a distance S measured from an edge of said printed circuit board in a lengthwise direction of said printed circuit board, said distance S being defined as one-fourth of a wavelength associated with a frequency to be depressed.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• and
• (c) a magnetic layer formed in said dielectric layer sandwiched between said ground layer and said power-supplying layer, said magnetic layer including a magnetic loss and occupying an area having an outer boundary spaced away from an edge of said printed circuit board by a distance S, said distance S being defined as one-fourth of a wavelength associated with a frequency to be depressed.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• and
• (c) a magnetic layer formed between said ground layer and said power-supplying layer, said magnetic layer including a magnetic loss and coextending with said printed circuit board.

A printed circuit board comprising:

• (a) at least one dielectric layer;
• (b) at least two metal layers one of which acts as a ground layer, another one of which acts as a power-supplying layer, and the others of which, if any, act as a wiring layer in which a signal pattern is formed, said dielectric layer and said metal layers being alternately formed one on another;
• and
• (c) an electrically insulating layer formed between said ground layer and said power-supplying layer, said electrically insulating layer including a magnetic loss.