Abstract: A heat sink and a method for manufacturing a heat sink are described. A plate-like base is manufactured with a plurality of parallel grooves and a plurality of fins by an impact extrusion process. A high temperature heat treatment is performed to soften the plate-like base. The fins are positioned in corresponding grooves and an equal force is applied to both ends of the plate-like base so that the grooves are deformed and the fins are fixedly positioned. The method is simpler and significantly cheaper than that for conventional heat sinks.

Abstract: A heat-radiating structure of chip provides effective heat-radiating paths and also maintains good structural stability to protect chips. A bearing rack is connected beside a flip chip type chip on a circuit substrate. The bearing rack is connected with a heat-radiating sheet. A projective portion is disposed at the center of the heat-radiating sheet facing the chip. The surfaces of the projective portion and the chip are connected together through adhesive. Several grooves are disposed on the surface of the heat-radiating sheet facing the chip to reduce the weight of the heat-radiating sheet and maintain its structural rigidity. Each side of the bearing rack is not connected together to avoid regions with a too large local thermal stress. Moreover, heat-spreading paths for hot, air are also provided to prevent the heat-radiating sheet from extra stress due to hot expansion and cold shrinkage during baking in the packaging process.

Abstract: A heat dissipation device includes a thermally conductive base plate and a plurality of thermally conductive fin plates that are in thermal communication with the base plate. Each adjacent pair of the fin plates defines a channel therebetween, through which cool air is forced to flow. Each of the fin plates has a proximate side that is proximate to the base plate, a distal side that is opposite to the base plate, and a plurality of integral ribs that extend from the proximate side to the distal side, thereby permitting heat transfer from the proximate side to the distal side along the ribs. In addition, because each of the ribs enables formation of a small turbulent flow of the cool air, a temperature boundary layer of the air is broken in each of the channels, thereby permitting heat transfer from upstream ends of the channels to downstream ends of the channels. Because the sizes of the ribs are relatively small with respect to the widths of the channels, the cool air can flow smoothly through the channels.

Abstract: An improved structure of an electric shock device includes a handle, and a plurality of retractable rod portions. The handle has an interior accommodating therein a high voltage generator and a battery unit. The handle further has a control switch at a lower rim thereof. The retractable rod portions are arranged and assembled in order of size, and equipped with a retractable function by utilizing springs and retaining rods disposed therein. The rod portions are made of insulating materials and respectively provided with parallel positive and negative electrode plates on both sides thereof. The electrode plates nearest to the handle are connected to positive and negative terminals of the high voltage generator so as to supply the rod portions with the required high voltages. The permittivity of dielectrics on the rod portions that have different diameters is caused to be equivalent so that the conductance conditions of the rod portions are the same, and the rod portions can all generate electric arcs.

Abstract: An assembly screw driver having a handle with a through hole connecting the front end and rear end of the handle; the through hole has a support device fixed therein near the front end of the handle to support and secure the base of the body of the screw driver. The body and the handle of the screw driver are detachable and the base of the body may be inserted via the rear end of the handle along the through hole to engage with the support device so that the body may be concealed in the handle.