Under the surface peeling of Cu- Fe- P lead frame alloy larger Fe particles were observed by energy dispersive spectroscopy. By using the large strain two-dinension plane strain model and elastic plastic finite elemen...Under the surface peeling of Cu- Fe- P lead frame alloy larger Fe particles were observed by energy dispersive spectroscopy. By using the large strain two-dinension plane strain model and elastic plastic finite element method, the cause for peeling damage of Cu-Fe-P lead frame aUoy was investigated. The results show that when the content of Fe particles is more than 30% at local Fe-rich area the intense stress coacentration in the Fe particle would make the Fe particle broken up. The high equivalent stress mutation and the mismatch of equivalent strain 10% at the two sides of intefrace make it easy to develop the crack and peeling damage on finish rolling. The larger Fe particles in the Cu-Fe-P alloy should be avoided.展开更多
Transmission electron microscopy (TEM) observations were carried out for examining the precipitation behavior in a Cu-Sn-Ni-Zn-P lead frame material. TEM observations revealed that the precipitate is hexagonal Ni5P2 a...Transmission electron microscopy (TEM) observations were carried out for examining the precipitation behavior in a Cu-Sn-Ni-Zn-P lead frame material. TEM observations revealed that the precipitate is hexagonal Ni5P2 and the orientation relationship between the Cu matrix and Ni$Pi precipitate is (111)fcc//(0001)hcp, [101]fcc//[1120]hcp, where the suffix fcc denotes the Cu matrix and hep denotes the hexagonal Ni5P2 precipitate. The Ni5P2 precipitate is ovoidal in shape at the beginning of aging at lower temperature. By prolonging the aging time or increasing the aging temperature, Ni5P2 precipitate grows and shows a rod-like shape. The Ni added Cu based lead frame material has a comparative mechanical properties with that of TAMAC15 which has been developed and used in electrical industry.展开更多
In the paper, the rough surface of KFC copper strip applied to lead frame was studied and analyzed. The method of energy spectrum analysis, SEM and metallographic analysis are adopted to study and analyze. To compare ...In the paper, the rough surface of KFC copper strip applied to lead frame was studied and analyzed. The method of energy spectrum analysis, SEM and metallographic analysis are adopted to study and analyze. To compare the component of the rough surface of KFC copper strip with one of the normal copper strip, the component abnormity is not found. But to observe its microstructure of the rough surface, there are thinner and regular dimpling in the surface before the polishing, and bigger crystal grains are found after the polishing. The coarse structure vanished when the sample is heated higher than 700℃. It is shown that current annealing technique is not reasonable and should be improved and optimized.展开更多
One of the key components in high-tech products,such as semiconductors,electronic connectors,and lithium batteries,is the lead frame,made from metals like copper and its alloys,as well as aluminum and its alloys,with ...One of the key components in high-tech products,such as semiconductors,electronic connectors,and lithium batteries,is the lead frame,made from metals like copper and its alloys,as well as aluminum and its alloys,with thicknesses ranging from 0.02 mm to 0.8 mm.In manufacturing,butt-joint and overlap-joint welding are crucial for enhancing productivity and minimizing solid waste.However,existing welding technologies face challenges with these types of joints.To overcome this,a novel spot-welding process has been developed using an advanced welding torch with a dual-layer nozzle system,comprising an inner and outer nozzle.This design offers several advantages:it precisely positions the tungsten electrode,extends its lifespan,prevents molten metal from evaporating and re-entering the melt pool,and ensures arc plasma stability.Additionally,the outer nozzle plays a crucial role in controlling the shape of the arc plasma column,melt pool formation,and the size of the welded spot.By integrating both nozzles,this technology enables welding at an extremely short arc length and low current,ensuring minimal heat input while maintaining a high-stability arc plasma,making it ideal for welding ultra-thin metal sheets.展开更多
基金Funded by the National "863" Plan of China ( No.2002AA331112) ,the Doctorate Foundation of Northwestern Poly-technical University,andthe Science Research Foundation of HenanUniversity of Science and Technology(No.2006ZY041)
文摘Under the surface peeling of Cu- Fe- P lead frame alloy larger Fe particles were observed by energy dispersive spectroscopy. By using the large strain two-dinension plane strain model and elastic plastic finite element method, the cause for peeling damage of Cu-Fe-P lead frame aUoy was investigated. The results show that when the content of Fe particles is more than 30% at local Fe-rich area the intense stress coacentration in the Fe particle would make the Fe particle broken up. The high equivalent stress mutation and the mismatch of equivalent strain 10% at the two sides of intefrace make it easy to develop the crack and peeling damage on finish rolling. The larger Fe particles in the Cu-Fe-P alloy should be avoided.
基金support of the National Natural Science Foundation of China(Grant No.59971008).
文摘Transmission electron microscopy (TEM) observations were carried out for examining the precipitation behavior in a Cu-Sn-Ni-Zn-P lead frame material. TEM observations revealed that the precipitate is hexagonal Ni5P2 and the orientation relationship between the Cu matrix and Ni$Pi precipitate is (111)fcc//(0001)hcp, [101]fcc//[1120]hcp, where the suffix fcc denotes the Cu matrix and hep denotes the hexagonal Ni5P2 precipitate. The Ni5P2 precipitate is ovoidal in shape at the beginning of aging at lower temperature. By prolonging the aging time or increasing the aging temperature, Ni5P2 precipitate grows and shows a rod-like shape. The Ni added Cu based lead frame material has a comparative mechanical properties with that of TAMAC15 which has been developed and used in electrical industry.
文摘In the paper, the rough surface of KFC copper strip applied to lead frame was studied and analyzed. The method of energy spectrum analysis, SEM and metallographic analysis are adopted to study and analyze. To compare the component of the rough surface of KFC copper strip with one of the normal copper strip, the component abnormity is not found. But to observe its microstructure of the rough surface, there are thinner and regular dimpling in the surface before the polishing, and bigger crystal grains are found after the polishing. The coarse structure vanished when the sample is heated higher than 700℃. It is shown that current annealing technique is not reasonable and should be improved and optimized.
基金supported by the funding from the Hanoi University of Industry(DHCN-No.3).
文摘One of the key components in high-tech products,such as semiconductors,electronic connectors,and lithium batteries,is the lead frame,made from metals like copper and its alloys,as well as aluminum and its alloys,with thicknesses ranging from 0.02 mm to 0.8 mm.In manufacturing,butt-joint and overlap-joint welding are crucial for enhancing productivity and minimizing solid waste.However,existing welding technologies face challenges with these types of joints.To overcome this,a novel spot-welding process has been developed using an advanced welding torch with a dual-layer nozzle system,comprising an inner and outer nozzle.This design offers several advantages:it precisely positions the tungsten electrode,extends its lifespan,prevents molten metal from evaporating and re-entering the melt pool,and ensures arc plasma stability.Additionally,the outer nozzle plays a crucial role in controlling the shape of the arc plasma column,melt pool formation,and the size of the welded spot.By integrating both nozzles,this technology enables welding at an extremely short arc length and low current,ensuring minimal heat input while maintaining a high-stability arc plasma,making it ideal for welding ultra-thin metal sheets.
