| 摘要 |
AN IMAGE INSPECTION METHOD AND APPARATUS IS PROVIDED FOR INSPECTING AN OBJECT, SUCH AS A SEMICONDUCTOR PACKAGE OR COMPONENT 100, WITH A TOP SURFACE AND A BOTTOM SURFACE HAVING FEATURES OF INTEREST TO BE INSPECTED. THE OBJECT IS ILLUMINATED BY A TOP ILLUMINATION 104 AND A BOTTOM ILLUMINATION 100 USING SMOOTH DIFFUSE LIGHT SUCH AS LED. FILTERS 105 MAY BE PLACED ABOUT THE OBJECT FOR BLOCKING THE TOP ILLUMINATION 104 ,FROM INTERFERING WITH THE BOTTOM ILLUMINATION 103 AT PERIPHERAL REGIONS WHILE ALLOWING THE UPWARDLY PROJECTING BOTTOM ILLUMINATION 103 TO PASS THROUGH TO BE CAPTURED BY AN IMAGE SENSOR CAPABLE OF SENSING THE WAVELENGTHS OF THE TOP AND BOTTOM ILLUMINATIONS 104 & 103. THE IMAGE SENSOR SUCH AS A CCD CAMERA 106 IS PLACED ABOVE THE OBJECT FOR CAPTURING AT THE CENTRE OF AN IMAGE FRAME THE TOP ILLUMINATION 104 REFLECTED OFF THE SURFACE AND AT THE PERIPHERY OF THE SAME IMAGE FRAME THE BOTTOM ILLUMINATION 103 REFLECTED OFF THE BOTTOM SURFACE. THE BOTTOM SURFACE IMAGE MAY ALSO BE REFRACTED WITH A PRISM TO BE CAPTURED BY THE CAMERA 106..
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