Electromagnetic shields for sub-modules of electronic modules are disclosed. Electronic modules may include multiple sub-modules arranged on a substrate with an electromagnetic shield arranged to conformally cover the sub-modules as well as portions of the substrate that are uncovered by the sub-modules. Electromagnetic shields are disclosed that are configured to extend between sub-modules to form one or more divider walls. The one or more divider walls may be configured to extend below mounting surfaces of electronic components in the sub-modules to provide improved reduction of electromagnetic interference (EMI) or crosstalk between various sub-modules. Electromagnetic shields are also disclosed that form perimeter sidewalls that extend below mounting surfaces of electronic components of sub-modules to provide improved reduction of EMI from other modules or other external sources.

A keyboard for secure data entry is provided. The keyboard comprises at least one or more of data entry buttons that can be depressed by a user. For each of the data entry buttons, a button actuator is provided that is movable upon the user depressing the respective data entry button and a primary capacitive sensor is provided that is arranged to determine movement of the button actuator of the respective data entry button by capacitance sampling. The button actuator is at least partly made from a conductive material. The button actuator is coupled to a defined electric potential at least during the capacitance sampling to shield the primary capacitive sensor from eavesdropping.

An active electromagnetic interference (EMI) filter includes a first amplifier and a second amplifier. The first amplifier is configured to sense noise signals on a power conductor. The second amplifier is coupled to the first amplifier and is configured to drive a cancellation signal onto the power conductor. The cancellation signal is to reduce the amplitude of the noise signals sensed by the first amplifier. An output impedance of the second amplifier is lower than an output impedance of the first amplifier.

An apparatus includes an electronic circuit, a keypad and an active-shield layer. The keypad includes one or more keys for entering data to the electronic circuit by a user. The active-shield layer is placed between the electronic circuit and the keypad, and includes one or more electrical conductors laid in a pattern that shields at least a portion of the electronic circuit. In a specified region, the one or more electrical conductors of the active-shield layer are shaped to form contacts for sensing the one or more keys.

Disclosed are a method of uniformly dispersing nickel-plated conductive particles of a single layer within a polymer film by applying a magnetic field to the polymer film and a method of fabricating an anisotropic conductive film using the same. The method of fabricating a film may include forming a liquefied polymer layer by roll-to-roll coating a polymer solution in which a plurality of conductive particles has been mixed, dispersing the plurality of conductive particles included in the liquefied polymer layer by applying a magnetic field to the liquefied polymer layer, and fabricating a solid polymer layer limiting a movement of the plurality of dispersed conductive particles by drying the liquefied polymer layer in which the plurality of conductive particles has been dispersed.

Various circuit board systems and methods of use and manufacture thereof are disclosed. A circuit board system can have a first circuit board including a substrate and a first component susceptible to electromagnetic interference carried by the substrate. The system can also include a second circuit board including a second substrate, and a shield engaged to the substrate of the first component, the shield at least partially covering the first component and being configured to protect the first component from electromagnetic interference, wherein the shield couples the substrate of the first circuit board to the substrate of the second circuit board.

Provided is an electromagnetic-wave absorber that can favorably absorb electromagnetic waves of a plurality of different frequencies in a high frequency band equal to or higher than the millimeter-wave band. The electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer 1 in which a plurality of magnetic layers 1a-1e are stacked, each magnetic layer containing magnetic iron oxide that magnetically resonates at a high frequency in a band equal to or higher than the millimeter-wave band. A value of an anisotropic magnetic field (H.sub.A) of the magnetic iron oxide contained in at least one of the magnetic layers is different from that of the magnetic iron oxide contained in another of the magnetic layers.

An electronic device having a shield structure is disclosed. The shield structure includes a conductive heat diffusion plate that is provided in a position facing a mounting surface of an electronic circuit board on which electronic components, such as a CPU, are mounted, and diffuses heat generated from the CPU, etc.; and a conductive sponge-like member that is firmly fixed to at least either the mounting surface of the electronic circuit board or a surface of the conductive heat diffusion plate which faces the mounting surface of the electronic circuit board, and is provided to separate the CPU, etc. which generate electromagnetic wave noise from antennas.

The present invention provides an electromagnetic wave suppression sheet provided with: an absorption layer which has surface resistivity of at least 100/ and which contains an electrical conductive material and an insulating material in the state where the electrical conductive material and the insulating material are in direct contact with each other, the insulating material having a dielectric loss tangent of 0.01 or larger at a frequency of 60 Hz at 20 C.; and a contact layer which is formed on a surface, of the absorption layer, opposite to a surface to be irradiated with electromagnetic waves and of which a surface in contact with the absorption layer has surface resistivity of at least 20/.

A vehicle electronic module is provided. The vehicle electronic module has a reduced size and improved productivity by replacing a sensor and an offset unit of an electromagnetic interference (EMI) filter module with a printed circuit board (PCB) winding structure. The electronic module includes a sensor that detects EMI noise of a power line and an offset unit that transmits an offset voltage for removing the EMI noise to the power line. A controller is configured to generate the offset voltage that corresponds to the EMI noise detected by the sensor. Then sensor and the offset unit are formed in a stacked structure of the PCB.