Calibration methods for placement machines incorporating on-head linescan sensing
AssigneeCyberOptics Corporation
InventorsTimothy A. Skunes, Eric P. Rudd, David W. Duquette
Life of this patent
Estimating the term…
Abstract
A method of calibrating a pick and place machine having an on-head linescan sensor is disclosed. The calibration includes obtaining z-axis height information of one or more nozzle tips via focus metric methods, including a Fourier transform method and a normalized correlation method. Additionally, other physical characteristics such as linear detector tilt, horizontal scale factor, and vertical scale factor are measured and compensated for in the process of placing the component. Nozzle runout, another physical characteristic, is also measured by a sinusoidal curve fit method, and the resulting Z-height calibration data is used to later place the component.
Claims13
A method calibrating a pick and place machine having a physical coordinate system and at least one nozzle, the method comprising:
- attaching a target to the at least one nozzle;
- imaging the target with an on-head line scan sensor to provide a scanned image expressed in terms of a linescan coordinate system;
- and
- computing a mapping between the physical coordinate system and the linescan coordinate system based on at least two features of the target;
- and
- computing a physical characteristic as a function of the mapping.
Dependencies are inferred from the claim text.