Ideally suitable for measurements in pick-and-place machines, e.g. for the inspection of coplanarity of IC pins.
The new optoNCDT 1320 and 1420 laser triangulation sensors from sensor specialist Micro-Epsilon are a world first in miniature design. They are used in pick-and-place machines, the food industry or in robot tasks. A special feature is the extremely small laser spot size, which enables high precision measurements of very small parts.
Using laser triangulation sensors, displacement, distance and position are measured on a non-contact, wear-free basis. The new optoNCDT 1320 and 1420 sensors from Micro-Epsilon are unique because for the first time, the sensors perfectly combine a compact design and integrated controller, with operation via a web interface and high precision measurements due to a small laser spot size. But where can these new compact sensors be used? One example that requires fast, high precision measurements in a minimum design envelope are automated pick-and-place machines, where extremely small components must be positioned the correct side up, at the correct location and at the correct height. Furthermore, pick-and-place machines present a unique challenge. Inspection of even smaller IC pins of a component must also be carried out in order to check that they are positioned at precisely the correct distance from the circuit board. These pins later enable connection to the circuit board. In order to guarantee proper soldering, the distance between both components must not be too high.
The so-called ‘coplanarity’ indicates if all the pins are arranged in line with each other and is therefore considered to be the critical factor that must be inspected using high precision measurement technology. The component is guided over a triangulation displacement sensor whose laser beam scans the pins. After calculation of the distance values, the sensor arrives at a decision on whether the component should be placed or removed. The requirements on the measurement technology are enormous; not only because the parts are extremely small, but also primarily due to the rapid change from shiny to matt surfaces.
The pins consist of a shiny metal, whereas the circuit board presents a matt surface. Therefore, the receiver element in the sensor is at frequent intervals alternately exposed to strong and then weak reflections – a task that the optoNCDT 1420 laser sensors are optimised to perform. The Auto Target Compensation (ATC) feature provides fast control of different reflections that occur during PCB assembly.
The laser triangulation measuring principle is based on a simple geometric relationship. Laser triangulation sensors are preferably used for high speed, high precision and high resolution measurements. A laser diode emits a laser beam, which is aimed at the target. A lens focuses the reflected rays onto a receiver element array. The distance to the measurement object can be determined by the three-point relationship between the laser diode, the measuring point on the target object, and the projection on the receiver element. Depending on the object surface, the reflected radiation is more or less intensive. Depending on the design, the optical principle supports measuring distances between a few millimetres to over one metre.
The diameter of the light spot on the target surface therefore stays small. Laser-based optical displacement sensors measure from a large distance to the target using a very small spot which enables measurements on the very small parts. The distance to the target enables measurement against critical surface for example in the food industry.
Compact and clever: the new generation of compact smart laser sensors.
The new generation of optical optoNCDT 1320 and 1420 Smart sensors is ultra compact and requires no external controller. The entire electronics for signal processing is housed in a compact sensor body. These sensors are ideal whenever easy integration and high precision measurements are required. In this sensor class, the operating concept is unique and is carried out using function keys or the innovative web interface. The sensor is connected to a PC using Ethernet. A standard web browser now offers a user-friendly interface. Using the preset enables the user to quickly select the appropriate sensor set up parameters for particular targets. In essence, this is all about the surface type of the target. A change of the presets leads to a change of the evaluation algorithm of the sensors. Weighing just 60g, the sensors are suitable for dynamic acceleration tasks on, for example, machine axes or robot arms. Measuring ranges of 10, 25 or 50mm are currently available. Further measuring ranges will be available soon. A high performance lens enables a small light spot size, which enables reliable detection of even the very smallest of target objects.
The optoNCDT 1320 is ideally suited for entry-level precision measurement tasks. The measuring rate is adjustable up to 2kHz. The ATC feature provides stable distance signal control regardless of target colour or brightness. This series of sensors can be operated via function key or via web interface where predefined settings are available.
The optoNCDT1420 offers a unique combination of speed, size, performance and application versatility for displacement, distance and position measurements. The sensor is used in restricted installation space or dynamic applications enabled by the lightweight combined with integrated controller. Even with measuring rates of up to 4kHz a precise result is achieved. Due to the universal setting and evaluation possibilities, the optoNCDT 1420 meets the requirements for use in high volume and OEM applications. As well as analogue voltage and current outputs, a digital RS422 interface provides distance information of the sensor. The fast parameter set up is done via web interface where presets and a quality slider for the selection of the measurement task are available. Furthermore, up to eight user-specific sensors settings can be stored and exported in the setup management. Loading these individual sensor settings enables extremely fast parameter set up e.g. for high volume applications.
The video signal display, the signal peak selection and a freely adjustable signal averaging enable to optimise the measurement task. The multifunction button enables quick sensor commissioning for easy measurement tasks. The connection is made either via a 3 metre-length cable with open ends or via a 0.3 metre-length pigtail with M12 connector.
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