Configuration of Optical Vision Measurement System

The optical Vision Measurement system is mainly composed of four parts: workbench, drive control, CCD camera system and software system. The working principle as follows:

The core structure of the automatic optical Vision Measurement system is a set of CCD camera system, AC servo control x, y workbench and image processing system.

When performing the inspection, first place the printed circuit board to be inspected on the workbench of the optical measurement system. After positioning, call out the measuring program of the product to be inspected.

The x, y workbench sends the circuit board under the lens. After the lens captures the image of the circuit board, the processor will move to the next position on the x, y workbench to capture it, and then perform the corresponding calculation.

By continuously processing the image, a higher inspection speed is obtained. The optical image detection system automatically standardizes the size of the PCB through the program. The actual value and tolerance to be measured can be input. After analysis, processing and judgment, defects are found and the location prompts are given. At the same time, files are generated, waiting for the operator to further confirm or send to the relevant department for improvement.

How to measure height with optical vision measurement system

Since the emergence of various micro-via technologies in 1995, the industry has gradually adopted technologies such as CO2 laser, UV/YAG laser and photo-imaging dielectric materials in mass production lines.

These new technologies have led to a change in the design concept of circuit boards, from the previous careful use of 0.3mm through holes to the extensive use of blind holes and micro-vias, especially in high-density applications (such as mobile phones, computers, various boards and IC packaging). Holes with aspect ratios greater than 8:1 and diameters less than 0.3mm have become increasingly common, especially on circuit boards for servers, substrates and workstations. How to control the quality of such through holes?

The principle of measuring height with optical image measurement system is based on finding the focal length difference between the two clearest surfaces at different heights.

From the perspective of physical optics, the so-called "clear" is the imaging between one focal length and two focal lengths. That is to say, within a certain section, the imaging is clear.

When the focal length difference between the two surfaces is accumulated during autofocus, the accuracy of the Z axis cannot be compared with that of the X and Y axes. This requires good control and technology, and the software must also have high technical content. The iqualitrol measuring instrument uses software jointly developed.

The light source can be adjusted arbitrarily in five circles, eight directions and forty blocks. The Z-axis accuracy can also be controlled at around 5um, which is really beyond the reach of other software.