Stampability evaluation method of copper and copper alloy sheets for leadframe and connector isn'testablished, though most of these parts are manufactured by stamping sheets. In this study, relationamong experiential order of stampability, mechanical properties obtained by tension, hardness andpunching test, and burr height of punched specimens is studied to propose the evaluation methods.Tensio tests were conducted in the high crosshead speed of 10{sup}3 mm/min. Punching tests wereconducted by using dies with a cylindrical punch which diameter is about 5mm. On the punchingtests,shearing characteristic curves or shearing stress-punch displacement curves of specimens wereobtained. From them, shearing strength and penetration depth D{sub}p of specimens weremeasured.And burr height H{sub}b of punched specimens were measured by scanning electron microscope.The values of H{sub}b and D{sub}p were divided by thickness of specimens to normalize irregularityof these thickness'.As a result, UTS, microhardness, shearing strength and normalized penetration depth D{sub}p/t were all in proportion to normalized burr height H{sub}b/ t or stampability in this study. It issupposed that hardness test is available for an easy evaluation method and punching test is availablefor an exact evaluation method of stampability.
展开▼
