Bildverarbeitungssystem zur Erfassung der Anschlußgeometrie elektronischer SMT-Bauelemente [thesis]

Frank Breitenbach, Klaus Feldmann, Manfred Geiger
2020
In the context of the present work, a measuring principle for the acquisition of the geometric parameters of connections of multi-pole SMT components was developed, implemented and characterized. The simulation of the realized image and the development of evaluation strategies for extracting the desired parameters from the recorded data sets represented further working points. Examinations on real components and test structures served to verify the measuring principle and evaluation algorithms.
more » ... luation algorithms. The new arrangement of CCD line camera to component (non-frontal observation) presented here for the first time has the advantage that only two-dimensional images need to be evaluated, but which contain some information about the third dimension. The use of a line scan camera requires the use of a linear displacement table, which moves the component to be measured in front of the camera, but has the great advantage that the resolution of the resulting line scan is limited only in the vertical direction (along the CCD line), laterally (along the Linear movement) but can be freely varied over a wide range. With the components used here, a vertical resolution of approx. 1 and a lateral image resolution of approx. 3.5 µm / pixel could be achieved. The lateral measurement resolution (image resolution taking into account the positioning accuracy of the linear table) was around 6.4 µm / pixel. The evaluation strategy comprises two steps: 1. Examination of the periodicity of the recorded row of connections 2. Determination of the geometrical parameters of a single (incorrectly positioned) connection The first step is implemented with the help of wavelet decomposition, which is a novelty in this area. For the second step, the six significant edges of the individual connection to be examined are calculated. The position of the edges relative to one another then provides, for example, the lead width or the lead height. Based on the edge slope, it can be concluded that the connections may be tilted. In the practical part of the work, [...]
doi:10.25593/3-87525-131-8 fatcat:k6ya464tgzcufd7zfvjjns345u