Components with free-form surfaces, undercuts or fine structures are difficult to inspect which requires great effort. In order to fulfill these measurement tasks reliably, a sensor technology expert offers advanced 3D sensors with high measurement accuracies in the micrometer range for detecting small defects. The use of a 3D matrix technology eliminates the need for time-consuming sequential scanning of the surface, which enables a faster process. The 3D sensors are ideal for a wide range of industries–from metal processing and battery production to industrial automation.

For sensors in the Surfacecontrol 3D series, Micro-Epsilon relies on non-contact measurement technology using optical methods - triangulation to be precise. The distance between the sensor and all points on a surface is measured using a triangular geometry: a so-called matrix projector in the sensor projects a striped pattern onto the surface of the measuring object with its LED light, the reflected light is recorded by two cameras in the sensor and evaluated using integrated signal processing based on trigonometric calculations. In this way, the sensor calculates the distance to each point on the surface of the measured object. The measuring method is suitable for a wide variety of surfaces, making it ideal for use in a wide range of applications and industries.

The sensors achieve recording speeds of up to 2.2 million 3D points per second, with each point having an x, y and z coordinate. Together, the measuring points result in a so-called 3D point cloud, which is generated in the sensor itself and output for further processing via standardized interfaces. It is used to generate and visualize measurement data for subsequent analysis and evaluation by software. The point clouds contain texture information of the measured object and can therefore reproduce a realistic image of the recorded object. To ensure the high quality of the products, all Micro-Epsilon sensors are calibrated and tested in the company‘s own factories and delivered ready for use with a test report.

Measuring the Smallest Components

The current generation of 3D snapshot sensors Surfacecontrol 3D are available with different measuring ranges, starting at 30 mm up to 575 mm - depending on the variant and area of application. The latest addition to the model series is the Surfacecontrol 3D 3500-30 sensor with a measuring range of 30 mm and an x/y resolution of just 8 µm. It is suitable for the inspection of measuring surfaces with 31 mm x 19.5 mm. For measurements in harsh production environments or for use on robots, the sensor is installed in a robust aluminum housing and certified to protection class IP67. With a z-axis repeatability precision of 0.25 µm, the Surfacecontrol detects even small flatness deviations and height differences. As there are no moving parts in the sensor, it is low maintenance and cannot wear out.

The precise sensors are used in electronics production, for example: here, coplanarity describes whether all contact points or soldering points of ball grid array (BGA) components lie in one plane. Deviations lead to poor electrical connections or cold solder joints. With the small measuring range of Micro-Epsilon‘s surfaceCONTROL sensors, a high-resolution 3D map of the BGA or contact points can be created - allowing users to immediately detect and rectify defects or cold solder joints. Due to the high precision, height differences, parallelism and coplanarity can be reliably detected. The decisive factors here are the extremely low measurement noise, the fast measurement time of the sensors and the high insensitivity to ambient light, which ensure the high quality of the measurement data of the finished components.

Fast Commissioning and Calibration

To provide users with the best possible support in detecting defects, the manufacturer offers 3D Inspect software, a tool for quick commissioning and setup of the sensors. The software receives the measurement data from the sensor via Ethernet and displays it in three dimensions. Users can then process, evaluate and assess the 3D data on the PC in 3D Inspect with numerous integrated measuring programs and, if required, transmit it to a control unit via Ethernet. The 3D data can also be saved on a data carrier using the software. The sensor can also be easily configured and parameterized using the software. Alternatively, customers can use an easy-to-integrate software development kit (SDK) based on the GigE Vision and Genicam industry standards. 

Author
Thomas Penski, Product Manager 3D sensor technology at Micro-Epsilon Messtechnik