| 摘要 |
<p>A method of calibrating a pick and place machine (31) having an on-head linescan sensor (64) 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.</p> |
