Author: DAHENG IMAGING Date: 2018-04-24
Industry: Semiconductor
Project: Stereo vision system measures solder paste's height and position
Background
Surface-mount technology (SMT) is a method for producing electronic circuits in which the components are mounted or placed directly onto the surface of printed circuit boards (PCBs). Before components are to be mounted or placed, the paste must be printed on PCB, and it is a material used to connect surface mount components to pads on the board. After pasting, the boards are placed on a conveyor belt by the pick-and-place machines. Then the components to be placed are removed from the tapes, tubes or trays and placed on the PCB by the numerical control pick-and-place machines. And then the boards with the components are conveyed into the oven where melt the solder particles in the solder paste and bond the component leads to the pads on the circuit board.
Solution
This new stereo vision inspection systems are commonly installed at the place where is in the middle position between the pasting and the mounting components. The solder paste's height and position on the flat boards is measured by stereo vision method. The basic stereo camera system consists of two cameras and a projected grating looking at the same object from different positions. Two cameras simultaneously capture the projected pattern. As for two cameras, the projected grating will be an encoding and help them to search the conjugate points separated on the left camera and on the right camera. The Z coordinate of the corresponding object point would be calculated by using the difference between the two image locations of the conjugate points, thereby getting the solder paste's height and 3D position which prove highly efficient for process improvements and quality achievements.
Presentation
Two DAHENG IMAGING MERCURY cameras are used in the successful stereo vision system, the high accuracy of its timestamp can provide a hint for the R&D engineer to check whether two images from two different cameras are simultaneous. And its precise and fast trigger respond can capture the instant very precisely. MERCURY camera's characters ensure the synchronization of two images which is an important key for a stereo vision.
Advantages
l High accuracy of timestamp
l High frame rate of U3 model
l Outstanding image quality
l Light weight and small size
l Capture the instant very precisely
l Work perfectly in the tough environments
l Stable multi-camera running
Related Products
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