Abstract: A robust windowing method of extracting Y0 and D0 values from wafer maps for utilizing the Poisson yield model is provided, in order to determine defects (i.e., failed circuits) associated with a batch of semiconductor wafers. Application of the method of the present invention provides an effective, parameter independent method of detecting reticle and repeating defects.

Abstract: A tool for the manufacture of the outer member of a cross groove type constant velocity ratio universal joint has two sets of first and second elements disposed circumferentially between one another about the axis of the tool with the elements having portions which interfit to define a surface whose shape corresponds to that required in the joint, the portions having formations which form the sets of grooves, and with the elements so shaped that portions of the first elements can be moved radially inwardly to disengage their formations from the grooves.

Abstract: A tool for use in manufacture of a hollow article with an undercut internal surface, such as the outer member of a constant velocity ratio universal joint, comprising first and second elements (34,38) together defining the shape required in the article interior and an internal cavity (40). An expander (23) fits in the cavity to hold the elements in their operative positions, and the first elements have parallel or outwardly convergent sides which enable their inward movement between the second elements after withdrawal of the expander from the cavity. After such inward movement, the first elements can be withdrawn from the shaped article, followed by the second elements.

Abstract: A tool, and method, for making the outer member of a constant velocity universal joint of the cross-groove type, the outer member being of hollow form having in its interior two sets of helical grooves of opposite hand. The tool comprises first and second parts 15, 21 mounted for axial movement relative to one another, the parts having portions 23, 17 which can be brought into and out of mutual intercalation by such axial movement, the portions 17 carrying projections 18 which form the grooves of one hand and the portions 23 carrying projections 24 which form the grooves of the other hand.