Abstract:
A part has a body unit; and one or more leg formed on the body unit. One or more slit is formed on the body unit adjacent to the leg. The legs are inserted to insert holes of a printed wiring board or the like and soldered thereto. Since the slit is formed adjacent to the leg, the heat applied to the leg for the soldering is not radiated by the body unit by virtue of the slit. Therefore, the part can be reliably attached to the printed wiring board or the like.
Abstract:
A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.
Abstract:
A multi-layer printed circuit board including at least one layer of an electrically conducting material and at least one layer of an electrically insulating material. At least one through hole formed at least through the at least one layer of electrically conducting material. The at least one through hole includes a material plated on an interior surface thereof. At least one thermal break is provided in the at least one layer of electrically conducting material, such that heat passing between the through hole and the at least one layer of electrically conducting material passes through the at least one thermal break. At least one electrical connection provided in the at least one layer of electrically conducting material between the material plated on the interior surface of the through hole and the at least one layer of electrically conducting material. At least a portion of the at least one electrical connection is between the through hole and the at least one thermal break.
Abstract:
A circuit substrate includes a plurality of electronic devices including a heat-generating electronic device, and a printed circuit board having the plurality of electronic devices mounted thereon and having a slit hole for thermally isolating a portion for mounting the heat-generating electronic device and a portion for mounting other electronic devices.
Abstract:
A printed wiring board and an electronic device using the same with which the formation of cracks in base portions of projecting external electrodes formed on lands on the printed wiring board is certainly prevented. With respect to a printed wiring board 11 having lands 16 formed in a wiring pattern where external electrodes 13 are to be formed and a pattern-protecting film 17 having openings 17a where the external electrodes 13 are to be formed, the opening diameter D1 of the openings 17a in the pattern-protecting film 17 is set greater by a predetermined dimension than the external diameter D2 of the lands 16 and a gap is thereby provided between each of the external electrodes 13 and the pattern-protecting film 17 so that the external electrodes 13 and the pattern-protecting film 17 do not make contact with each other and as a result there is no cracking of the external electrodes 13 caused by differential thermal expansion of the external electrodes 13 and the pattern-protecting film 17. An electronic module comprising the electronic device of the invention mounted on a mother board can be widely used by being incorporated into various types of electronic equipment.
Abstract:
An electronic device comprises a substrate having electronic parts, electric conductive wires for electrically connecting between the electronic parts, a front surface on which the electronic parts and electric conductive wires are mounted, a reverse surface and at least one electronic part back portion opposite to the electronic parts; and at least one high thermal conductivity member, a thermal conductivity coefficient thereof being higher than that of the substrate, the high thermal conductivity member being connected to the electronic part back portion while the high thermal conductivity member is opposite to the electronic parts in a substrate width direction to decrease a difference in temperature between the electronic parts.
Abstract:
A ball grid array (BGA) package which has a plurality of solder balls attached to solder landings that each have a number of tabs which extend from a center area of the landing. The tabs assist in a symmetric formation of solder balls that are formed on the landings. When constructing the package, a solder mask is applied to a bottom package surface before the application of the solder balls. The solder mask has a plurality of openings which expose the solder landings and are larger than the center area of the landings. Solder balls are then placed onto the solder landings and reflowed so that the balls become attached to the landings. The fully exposed center areas of the solder landings allow the solder to flow vertically along the outer walls of the landings, thereby providing a more robust solder joint. The exposed solder landings also allow a solder flux to be thoroughly cleaned after the solder balls are attached to the landings. Additionally, the land tabs insure an even solder flow about the solder landings to produce a symmetric uniform solder balls.
Abstract:
A method of forming a multi-layer circuit board or card. The method includes the step of forming a plurality of conductive planes. The conductive planes include ground, signal, or power planes. At least one through hole is formed through at least one of the conductive planes. An electrically conductive material is deposited onto an inside surface of the at least one through hole to form a plated through hole. At least one thermal relief passage is formed at least in the at least one of the conductive planes for preventing the diffusion of heat throughout the circuit board or card during the securing or removal or chips or other components to the circuit board or card by heating the material deposited in the at least one through hole to a temperature above its melting point. The at least one thermal relief passage is located in the vicinity of the at least one through hole and is free from electrical connection therewith. An electrically insulating material is deposited on at least one side of each of the conductive planes. The planes are placed on top of each other such that a layer of electrically insulating material is located between each of the conductive planes. The conductive planes are joined together to form the multi-layer circuit board or card.
Abstract:
In a mounting board, two through-holes are formed which are used for inserting both ends of a supporting member for a vibrator. On a surface of the mounting board, a ground conductor pattern is formed. In the ground conductor pattern, two portions of arcs, where the ground conductor pattern is removed, are formed on respective peripheries of the two through-holes. Furthermore, on the mounting board, two connecting conductor patterns are formed on surfaces of portions defined by the two through-holes and so on, so as to extend from the ground conductor pattern. Both ends of the supporting member for the vibrator are respectively inserted into the two through-holes and soldered to two connecting conductor patterns.
Abstract:
A circuit board includes a circuit-conductor layer, a ground layer and a power source layer superposed in a multilayer form through dielectric layers therebetween, A heat conduction through inside of the circuit board is enhanced so that circuit chips mounted on the circuit board can be cooled down to a level capable of operating normally, The circuit board can be formed to be compact, In order to enhance the heat transfer in the circuit board, at least one of the ground layer and power source layer is formed in a multilayer manner, It is preferable to form these layers at a thickness larger than that of the circuit-conductor layer, Further, preferably, the pin of the chip mounted on the board and at least one of the ground layer and power supply layer are connected to each other in such a manner as to enhance the heat conduction.