Abstract: A circuit board assembly includes a circuit board with two heat dissipating assemblies mounted thereon and an L-shaped back plate attached to an underside of the circuit board. Each of the heat dissipating assembly includes at least a pair of securing members at opposite corners thereof. The back plate includes a first portion and a second portion each defining at least a pair of circular protrusions corresponding to the securing members of the heat dissipating assemblies.

Abstract: A heat dissipation apparatus for dissipating heat from two heat sources includes a heat sink, and a fan mounted on the heat sink. The heat sink includes a base and a plurality of parallel fins positioned on the base, the base contacts with one of the two heat sources for thermally conducting the heat generated by the one of the two heat sources. The fan is configured to generate airflow through the fins in such a manner that airflow flows from a second side of the fins to a first side of the fins. A deflecting member is mounted on the first side of the fins for deflecting airflow from the fan towards the second of the two heat sources.

Abstract: A heat sink assembly includes a printed circuit board, a socket attached on a top surface of the board for receiving a chip, and a heat sink attached onto the chip of the board. The socket includes a plurality of legs integrally extending down from a bottom surface of the socket. The legs contact the top surface of the board to support the socket on the board. The heat sink includes a base, a plurality of fins extending up from the base, and a plurality of legs extending down from the base.

Abstract: A computer enclosure includes a chassis with a plurality of heat generating components installed therein and an airflow guide structure. The airflow guide structure includes a fan and a duct attached to the fan. A pair of airflow outlets aligned with the fan is defined in the duct. The duct includes a plurality of pivot panels pivotally attached at airflow outlets. The pivot panels are configured to guide airflow from the fan to different positions of heat generating components in the chassis.

Abstract: A circuit board includes a signal plane and a ground plane. The signal plane is configured to have a plurality of signal traces arranged thereon. Each of the signal traces includes a plurality of straight line segments. Each line segment extends along a path different from the others. The ground plane includes a plurality of tiles connected in an array. Each tile is formed by ground traces. The straight line segments of each signal trace mapped on the ground plane are arranged at an angle relative to any one ground trace of the tiles. The angle is defined within a range determined by one of ground traces of a tile and an adjacent diagonal line of the tile. A method for laying out such a circuit board is also provided.

Abstract: A mounting apparatus for mounting a heat sink on a board, includes a first locking hole defined in the heat sink, a second locking hole defined in the board, and a locking member. The locking member includes a base and a rod. The base defines a hole. A bottom of the base forms a pair of separated elastic claws around the hole. The elastic claws are inserted through the first and second locking holes. The rod includes an expanded portion. The rod slides in the hole of the base with the expanded portion located inbetween the claws to expand the claws outwards to be larger than the second locking hole to lock the locking member on the board and to mount the heat sink on the board.

Abstract: A circuit board is provided for improving signal quality, including a signal plane for a plurality of signal traces arranged thereon and a ground plane formed by a plurality of tiles connected to each other in an array. Each tile is formed by ground traces. Different line segments of a signal trace mapped on the ground plane cross ground traces of the tiles at similar angles, thereby minimizing interaction between the ground traces and the signal traces to reduce differences in impedances of the signal traces.

Abstract: A heat sink for dissipating heat from a heat source, includes a base configured to connect with a heat source, and a plurality of fins positioned on the base. A cutout is defined within the plurality of parallel fins.

Abstract: A heat dissipating device is provided. The heat dissipating device includes a seat and a plurality of fins secured on the seat. The fins are regularly aligned in a matrix. A first set of fins comprise of a convex profile.

Abstract: A chip package structure comprises a carrier, a chip and an underfill. The chip has an active surface on which a plurality of bumps is formed. The chip is flip-chip bonded onto the carrier with the active surface facing the carrier, and is electrically connected to the carrier through the bumps. The underfill is filled between the chip and the carrier. A portion of the underfill near the chip serves as a first underfill portion. The portion of the underfill near the carrier serves as a second underfill portion. The Young's modulus of the first underfill portion is smaller than the Young's modulus of the second underfill portion. The second underfill portion can be optionally replaced with a selected encapsulation. The selected encapsulation covers the chip and the carrier around the chip.

Abstract: In one preferred embodiment, an objective lens actuator includes a base, a suspension apparatus mounted on the base, a holder suspended by the suspension apparatus for holding an objective lens, a voice coil motor (VCM) for driving the holder to vibrate, and a cover. The VCM includes a first yoke, a second yoke and a pair of magnets fixed on the first yoke and the second yoke respectively. The first yoke and the second yoke respectively include a first part and a second part. The cover is made of a material having a magnetic conductivity. The cover connects the first part and the second part of each of the first yoke and the second yoke.

Abstract: A heat sink assembly includes a printed circuit board, an electronic component mounted on the printed circuit board, and a heat sink mounted on the printed circuit board for dissipating heat from the electronic component. The printed circuit board includes a heat-conduction layer. The heat sink includes a base configured to contact the heat-conduction layer, and a main body extending upward from the base configured to contact the electronic component. The cross section of the base is larger than the cross section of the main body. A plurality of fins extends from the main body.

Abstract: A printed circuit board includes a base and a signal trace laid on the base. The signal trace includes a plurality of straight line segments parallel to the first fibers. The signal trace is laid on the base in such a manner that the line segments of the signal trace mapped on the base partly superpose the first fibers and partly superpose gaps between two adjacent first fibers.

Abstract: An electronic apparatus includes an enclosure (30), a circuit board (40), a fan module (20), and an air guiding element (10) mounted in the enclosure. The circuit board includes at least one heat generating component (41) thereon. The fan module has a fan (22) and an output opening (213) corresponding to the fan. The air guiding element comprises a resisting panel (11) and a guiding panel (12) comprises a free end that extends toward the output opening of the fan module. The at least one heat generating component and the output opening are on the same side of the resisting panel. The guiding panel defines a free end (127) and a connecting end (125) connecting the resisting panel. A plane defined by the ends of the guiding panel is aligned at an angle larger than 90 degrees relative to the resisting panel.

Abstract: A mounting apparatus for mounting a heat sink on a board, includes a first locking hole defined in the heat sink, a second locking hole defined in the board, and a locking member. The locking member includes a base and a rod. The base defines a hole. A bottom of the base forms a pair of separated elastic claws around the hole. The elastic claws are inserted through the first and second locking holes. The rod includes an expanded portion. The rod slides in the hole of the base with the expanded portion located inbetween the claws to expand the claws outwards to be larger than the second locking hole to lock the locking member on the board and to mount the heat sink on the board.

Abstract: A printed circuit board assembly includes a printed circuit board, a carrier, a semiconductor chip mounted on the carrier, a plurality of tin balls soldered between the printed circuit board and the carrier for transmitting signals, and a heat sink glued to the semiconductor chip to dissipate heat. A pressing portion is formed on the bottom of the heat sink and does not make contact with the semiconductor chip. The pressing portion contacts with the periphery of the carrier to reinforce the tin balls located between the printed circuit board and the carrier.

Abstract: An electronic device includes an enclosure (30), a circuit board (40), and an airflow guiding duct (10). The enclosure includes a bottom wall (31) and a rear wall (32) perpendicular to the bottom wall. The circuit board is mounted on the bottom wall of the enclosure. The circuit board includes a first heat generating element (41) and a second heat generating element (42) near to the first heat generating element. The airflow guiding duct includes two side panels (11) and a connecting panel (13) connecting a pair of side edges (112) of the two side panels. A first opening (17) is defined by a lower edge (131) of the connecting panel and lower edges (111) of the two side panels and corresponding to the first heat generating element. The lower edges of the two side panels and the lower of the connecting panel are in the same plane. The first opening is a predetermined distance from the circuit board and the airflow guiding duct is capable of allowing air flow from different directions.

Abstract: A button assembly for pressing a switch in a computer bezel includes a button connected to an arm. A cutout is defined in the computer bezel. The button is inserted in the cutout, and the arm is pivotably mounted on the computer bezel. A pressing portion extends outward from a side of the arm. A slanted pressing plane is formed on the pressing portion. Pressing the button moves the arm so that one end of the slanted pressing plane away from the arm contacts the switch. The switch resists the pressing portion, causing the arm to rotate so that the other end of the slanted pressing plane moves forward, thereby the slanted pressing plane entirely contacts and activates the switch.

Abstract: The invention related to a method and circuit that is used to compensate for S-parameters of a passive circuit which do not satisfy passivity. The method includes the following steps: (1) getting S-parameters which do not satisfy passivity, these S-parameters being composed of an S-parameter matrix S; (2) computing matrix [S×S?], wherein matrix S? is a complex conjugate transposed matrix of the S-parameter matrix S; (3) computing the eigenvalues of the matrix [S×S?], and choosing an eigenvalue ? whose real part real(?) is the biggest; (4) computing a compensating value ?, the compensating value ? being equal to real(?)1/2×(1+?), wherein the ? is a very small positive number; and (5) dividing each of the S-parameters by the compensating value ? to get the compensated S-parameters.

Abstract: A printed circuit board assembly includes a printed circuit board with a heat generating component attached thereon, a base, and a thermal plate. The heat generating component comprises a side surface. The base defines a receiving room and an opening configured for access into the receiving room. The printed circuit board is received in the receiving room via the opening. The thermal plate is mounted on the base to cover the opening. A conducting piece is formed on the thermal plate and extends into the receiving room. The conducting piece includes a contacting portion extending from the thermal plate and in contact with the side surface. The conducting piece is configured for conducting heat from the heat generating component to the thermal plate. A heat dissipating hole is defined on the thermal plate in alignment with the contacting portion configured for dissipating heat from the base.