A three-dimensional inspection system is used to obtain three-dimensional information pertaining to an article having specular surfaces, such as a BGA device, by projecting a pattern of light onto the article at an oblique angle with respect to the article. The system includes patterned light projector having an optical axis disposed at an oblique angle with respect to the plane of the article being inspected and an image detector or camera disposed generally above the article being inspected to detect the image of the pattern projected on the article. The patterned light projector includes an extended light source that directs light along the optical axis and a light patterning member disposed at an angle with respect to the optical axis such that the light pattern is in focus in an image plane parallel to the plane of the article, thereby satisfying the Scheimpflug condition. The light pattern preferably includes lines of light projected onto the article with a substantially equal thickness and spacing. The spacing of the lines is preferably greater than a spacing or pitch of the specular elements, such as the solder balls on a BGA device. An image processor is coupled to the image detector to receive the image, locate the lines, and measure the lateral shift of the lines. Height information is determined from the lateral shift and projection angle using triangulation.
The present invention provides a bump shape measuring apparatus comprising an illumination optical system which illuminates bumps arranged on a board with illumination light of a low tilt angle to a surface of the board; a detection optical system where reflected light from the bumps is condensed for detection of image signals of the bumps by a high tilt angle to the surface of the board; an image processing unit where an outline of the tip and the base of each of the bumps is calculated based on the image signals of each of the bumps, and geometric characteristics including at least a position and height of each of the bumps are calculated based on the outline of the tip and the base of each of the bumps; and a main control unit where information on the calculated geometric characteristics of the bumps is displayed on a display unit.
A system for measuring the spatial dimensions of a three-dimensional object employs a lens and at least two detectors. The combination of which defines two or more object planes. The combination of the lens and the detectors define an optical axis that is normal to the object planes and passes through a focal point of the lens. At least a first and a second photodetector are optically aligned with the object through the lens. The first and second photodetectors or array of detectors are further parallel with the surface but have differing elevations relative to that surface. In addition, the first and second photodetectors are capable of motion relative to said object. Electrical output from the first and from the second photodetectors is provided to a processor that determines a distance of the object from the lens and thereby a height of the object. This system is particularly suited for measuring the spatial dimensions of solder balls mounted to a surface of a ball grid array (BGA) electronic package.
A method and arrangement are disclosed for increasing the depth contrast in microscope imaging. The method and implementation described can be designated as structured illumination for generating quasi-confocal optical sections. In implementing the method, a grating structure located in the field diaphragm plane of a microscope, the object plane and the TV intermediate image plane of a microscope are arranged confocally. The term "confocally" refers to the fact that the grating, object and the intermediate image plane are positioned on optically conjugate planes. By this arrangement, the grating structure is projected in the object plane of the microscope and the object which is structured in this way is imaged in the TV intermediate image plane of the microscope by the optical system following it. Optical sections are generated by calculating the modulation depth of the structured object. Three-dimensional acquisition of the object is achieved in that the object is imaged in a plurality of focus planes at right angles to the direction of observation and is detected using an array detector (e.g., CCD camera). The method and implementation of structured illumination described herein can primarily be used in reflection microscopy and fluorescence microscopy. In principle, the method can be applied for all linear interactions between light and matter. The use of the method is likewise not limited to the field of microscopy.
A system for measuring the spatial dimensions of a three-dimensional object employs a lens and at least two detectors. The combination of which defines two or more object planes. The combination of the lens and the detectors define an optical axis that is normal to the object planes and passes through a focal point of the lens. At least a first and a second photodetector are optically aligned with the object through the lens. The first and second photodetectors or array of detectors are further parallel with the surface but have differing elevations relative to that surface. In addition, the first and second photodetectors are capable of motion relative to said object. Electrical output from the first and from the second photodetectors is provided to a processor that determines a distance of the object from the lens and thereby a height of the object. This system is particularly suited for measuring the spatial dimensions of solder balls mounted to a surface of a ball grid array (BGA) electronic package.
A system and method are provided which enable parallel image reconstruction of multiple depth layers of an object. More specifically, a system and method are provided in which pixels are captured for an object and such pixels are processed to reconstruct voxels for multiple depth layers of the object in parallel. In one embodiment, a reconstruction processor comprises at least one input port for receiving pixels of a radiographic image of an object, and at least one input port for receiving position data associated with a received pixel. It further comprises processing logic operable to determine, based at least in part on the received position data of a received pixel, a first and second voxel of a first and second layer of the object, respectively, to which the received pixel contributes, and further operable to apply the contribution of the received pixel to the first and second voxels in parallel.
