ANALYSIS OF SINGLE-SIDE SHEARING BY USING PUNCH WITH HIGH SLENDERNESSRATIO

Shearing of thin sheet metal has often relied on the photo etching met hod [Thin Film Microelectronics, p. 95, 252, Chapman and Hall (1965); Appl. Phys. 27(9), 1 (1975); Metals Handbook, p. 240, ASME (1967)] [1- 3]. This is because electronic parts are generally extremely small in size and highly precise in form. The lead frame for IC and LSI integra ted circuits is an example of the products obtained by this method. Sh earing of such small and delicate parts in commercial quantities requi res a carefully designed and manufactured shearing tool and die [J. Ja p. Soc. Technol. Plastic. 33(379), 971 (1992); J. Mater. Process Techn ol. 32(3), 571 (1995)] [4, 5]. The tool must be slender enough to prod uce narrow slots and small holes; therefore, the tool lacks rigidity a nd may malfunction, damaging the tool surfaces as the tool buckles and binds, or if the buckling is excessive, breaking completely. This pap er reports and discusses the theoretical analysis and experiments conc erning several kinds of punch bending caused by the shearing force and side force. The knowledge of the side force acting on the shearing to ol is necessary for the analysis of shearing phenomena and the design of shearing tools. (C) 1997 Elsevier Science Ltd. All rights reserved.