High precision semiconductor component alignment systems

Abstract

High speed high precision alignment sensor systems for use on surface mount component placement machines. Light systems are used to correctly align and position component parts. The sensor system consists of a light source and an optical lens system causing more of the light from a light source to pass the component in order to obtain a sharper component image on a sensor array. Due to the optical lens systems disclosed, either low powered lasers, light emitting diodes, or other suitable light sources can be used in the system since optical efficiency is substantially increased over prior systems since more of the radiated light is collected from the light source for measurement at the detector. The sensor system is mounted directly on the carrying mechanism for the surface mount component placement machine. During transit of the component between the bin of components and the circuit board upon which the component is to be placed, the component is rotated and the sharp shadow which falls on the detector array is monitored. Several processing algorithms are disclosed for determining correct component angular orientation and coordinate (X,Y) location of the component on the quill. Thereafter, the sensor sends correcting signals to the component placement machine.