Patent ID: 6691574
Filing Date: 2004-02-17
Classification: B06B,G01N,H01L

Abstract:
A method for measuring a component Ay of an amplitude of oscillations of a tip of a capillary of a wire bonder which is clamped to a horn to which ultrasonics can be applied from an ultrasonic transducer, whereby measurement is based on a shading of a light beam by the capillary and whereby an intensity of the light beam is measured by an opto-receiver, comprising the following steps:Placing the capillary at one side of the light beam without the capillary shading the light beam and applying ultrasonics to the horn; Moving the capillary in a predetermined number of n steps into the light beam or completely through the light beam along a predetermined direction, whereby, at each of the i=1 to n steps, a direct voltage portion UDC(yi) and an alternating voltage portion UAC(yi) of an output signal of the opto-receiver as well as a co-ordinate yi are determined, whereby the co-ordinate yi designates a position of the capillary in relation to a co-ordinate axis y running perpendicularly to the light beam and whereby the component Ay to be measured runs in direction of the co-ordinate axis y; Calculating sensitivity values Si(yi) as a derivation of the direct voltage portion UDC(yi) with respect to the co-ordinate axis y as Si&af;(yi)=&dd;UDC&af;(yi)&dd;y;Selecting at least four measurement points and, for each of these at least four measurement points, calculating a value Ay,i as Ay,i=UAC&af;(yi)Si&af;(yi);â€ƒand Calculating the component Ay as an average from the values Ay,i.