A system and method of determining a height and/or position of at least one element on an area array device. A laser beam scans the area array device using at least two different laser light intensities. Reflected light is sampled, and the height and/or position of the element is determined using, e.g., optical triangulation.

Systems and methods for multi-dimensional metrology and inspection of a specimen such as a bumped wafer are provided. One method includes scanning the specimen with partial oblique illumination to form an image of the structure, either through the normal collection angle or through an oblique collection angle. The method also includes integrating an intensity of the image and determining a height of the structure from the integrated intensity. The integrated intensity may be approximately proportional or inversely proportional to the height of the structure. In addition, the method may include scanning the specimen with bright field illumination to form a bright field image of the specimen. The method may also include determining a lateral dimension of the structure from the bright field image. Furthermore, the method may include detecting defects on the specimen from the bright field image or the obliquely-illuminated image.

A scaling device projects a known optical pattern into the field of view of a camera, which can be employed as a reference scale in a resulting photograph of a remote object, for example. The device comprises an optical beam projector that projects two or more spaced, parallel optical beams onto a surface of a remotely located object to be photographed. The resulting beam spots or lines on the object are spaced from one another by a known, predetermined distance. As a result, the size of other objects or features in the photograph can be determined through comparison of their size to the known distance between the beam spots. Preferably, the device is a small, battery-powered device that can be attached to a camera and employs one or more laser light sources and associated optics to generate the parallel light beams. In a first embodiment of the invention, a single laser light source is employed, but multiple parallel beams are generated thereby through use of beam splitting optics. In another embodiment, multiple individual laser light sources are employed that are mounted in the device parallel to one another to generate the multiple parallel beams.

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.

A method of measuring solder bumps formed on a substrate mounting a semiconductor element thereon includes mounting a work to be measured on a work position mechanism, and scanning the work by an optical micro head to measure errors of a mount posture of the work. Each stage is controlled to correct the errors, and thereafter, the apex positions of the bumps are scanned and measured. The measurement results are collected by a personal computer, and the measurement results together with control data of each axis are sent to a main personal computer and displayed on its screen. An error of an apex position of each bump from a regression plane is calculated, and if the error is smaller than a reference value, the work is judged to be satisfactory.