Sensor applications for driving efficiency in electronics production
The manufacturing volume for electronics parts such as printed circuit boards (PCB) is steadily rising to keep up with economic demand. The industry has introduced parts miniaturisation and high-speed production systems to be able to reach production quotas. Advanced sensor technology is used to ensure reliable measurement, monitoring and inspection at every stage of the manufacturing process. This is to ensure the highest quality for the manufactured products.
The sensor requirements for such applications should be compact, easy to integrate into existing machinery and able to measure at high speed. An example of such technology is a non-contact laser triangulation sensor for measuring distance, displacement, position and thickness. The laser triangulation sensor has a compact design and is capable of adapting to rapidly changing surfaces while retaining its superior measurement accuracy. Some example applications of laser triangulation sensors in electronics manufacturing are outlined here.
Monitoring the presence and position of components in PCBs
Laser triangulation sensors have been previously used in a fully automated system to monitor the position of components in a PCB. Generally, the components in a PCB are miniature and cannot be easily detected with conventional measuring equipment. The blue laser triangulation sensors have a shorter wavelength and can measure at a higher resolution, which is suitable for this application. They also have a high measuring rate to enable short cycle testing in the production environment.
Print head positioning in laser printers
The exact distance from the print head to the object is crucial to ensure high quality of the final products in production processes. Laser triangulation sensors are compact and can be easily mounted on the print head for accurate distance detection. Conjunctively, the sensors can also measure the depth of the scribe line in the PCB to ensure that the printed components are separated.
Distance measurement in adhesive dispensers
Laser sensors have also been previously used on the glue dispensing machine. The sensors are mounted on the dispensing head to ensure that the adhesive dispenser is always at the correct working distance to the object. The advantage of using laser sensors for this application is the sensors’ capability to adapt quickly to a changing surface, ie, when the products move in the production line. They can continuously provide accurate distance measurement with high reliability.
Similarly, the laser triangulation sensors can also be used to detect the height of the paste bead during automated applications of heat conducting paste in electronics such as in LED light production. The dosage is determined by the height of the paste bead. It is crucial to achieve the correct dosage, as overloading of paste impairs its thermal resistance and too little paste may overheat the parts.
Other sensors requirements
A non-contact confocal displacement sensor can be used to measure the thickness of the protective coating on the PCB. The protective coatings are essential to protect the board from environmentally degrading compounds such as moisture. The confocal displacement sensors are suitable for this application due to their capability to achieve high-precision measurement on multi-layered objects and on thin layers, which is a limitation for laser sensors. Confocal sensors can also be used to measure the assembly gap on display glass on smartphones after the assembly process.
Bestech Australia partners with Micro-Epsilon, a world-leading company in high-precision sensors and instrumentation, to provide high-quality sensors and support for test and measurement applications in Australia and New Zealand. In addition to laser triangulation sensors, we also offer a wide variety of high-precision non-contact sensors to cover almost all measurement requirements in the electronics industry, from chip production to complex assembly monitoring.