Abstract: A process for laser forming a blind via in at least one layer of a circuit substrate having a plurality of capture pads of varying geometry can include, for at least one blind via to be formed in at least one layer of a circuit substrate, evaluating a capture pad geometry value (such as area and/or volume) within a predetermined distance from a drilling location with respect to a blind via geometry value (such as area and/or volume) to be formed at the drilling location. The process can include setting at least one laser operating parameter based on the evaluation in order to obtain a desired capture pad appearance after blind via formation. The process can include imaging a capture pad area defined as an area within a predetermined distance from a blind via drilling location in at least one layer of a circuit substrate, quantifying at least one appearance value for the imaged capture pad area, and determining an acceptability of the imaged capture pad areas based on the quantified appearance value.

Abstract: Systems and methods are provided for achieving convergent light rays emitted by a planar array of light sources. In one embodiment, an imaging device is provided for inspecting semiconductors or other objects. The imaging device includes one or more imaging lens for imaging light reflected from an object. The imaging device also includes a first light source attached to a planar circuit board and a second light source attached to the planar circuit board. The imaging device further includes a first Fresnel prism for directing light from the first light source toward the object from a first direction and a second Fresnel prism for directing light from the second light source toward the object from a second direction. In one embodiment, the imaging device also includes one or more optical elements for increasing or decreasing the divergence of the light.

Abstract: Systems and methods are provided for imaging a planar specular object such as a semiconductor wafer. In one embodiment, an imaging system for imaging a defect on a planar specular object includes a telecentric lens having a sufficiently aspherical surface such that the telecentric lens is substantially corrected for an optical aberration. The imaging system also includes a telecentric stop including an aperture therein to block light reflected from the planar specular object while allowing light reflected from the defect to pass through the aperture. The imaging system further includes a lens group having a system stop positioned between the telecentric stop and the lens group. The lens group is substantially corrected for the optical aberration independent of the telecentric lens.

Abstract: A method of removing an artifact resulting from an in-line illumination device of an imaging system from an object image. It includes obtaining a first image of the artifact using a first artifact illumination level and imaging the object using the imaging system wherein the illumination device is using an object illumination level. An artifact image is independent of the object and has pixel values related to the illumination level. Thus, the artifact can be removed by subtracting respective pixel values of an artifact image from respective values of the object image on a pixel address-by-pixel address basis. Various illumination levels can be used to create more than one artifact image. The artifact image for the subtraction can be one of the images taken or can be a scaled image where an artifact image is scaled to the object illumination level.

Abstract: A coaxial narrow angle dark field imaging system is provided. The system utilizes a telecentric lens to illuminate objects with symmetric coaxial narrow angle dark field illumination. The illumination technique is particularly suited to highlight minor features or defects on planar specular objects. In particular, the coaxial light source directs light rays towards a telecentric lens which redirects the light rays towards the substantially planar specular object. The light rays are reflected back through the telecentric lens towards a camera. To the extent that the light rays are reflected from a planar specular portion of the object the light rays are blocked by a telecentric stop. Light rays reflected from a defect or feature in the planar specular object will pass through an aperture in the stop to a camera.

Abstract: A coaxial narrow angle dark field imaging system is provided. The system utilizes a telecentric lens to illuminate objects with symmetric coaxial narrow angle dark field illumination. The illumination technique is particularly suited to highlight minor features or defects on planar specular objects. In particular, the coaxial light source directs light rays towards a telecentric lens which redirects the light rays towards the substantially planar specular object. The light rays are reflected back through the telecentric lens towards a camera. To the extent that the light rays are reflected from a planar specular portion of the object the light rays are blocked by a telecentric stop. Light rays reflected from a defect or feature in the planar specular object will pass through an aperture in the stop to a camera.

Abstract: The present invention provides a light source which improves the lighting for objects which include a nontrivial bi-directional reflectance distribution function and a nominal illumination angle. A two dimensional light source is positioned at an angle which is complementary to the nominal illumination angle such that the object is illuminated at its nominal illumination angle.