Permanent change leads to success

The two companies Laudren Electronique and Ersa GmbH have known and valued each other for a good eight years – in 2014, the business contact turned into a real business relationship when an Ersa selective soldering system of the type VERSAFLOW 3/66 was purchased for big boards. The requirement set by the French EMS service provider for a concrete project was: selective soldering technology. This is understandable, since current printed circuit boards are becoming increasingly complex – more and more components need to be placed, high-mix, low-volume is becoming the order of the day for sophisticated assemblies. In this case, an XL board format was also part of the requirement package, which is mastered perfectly by the Ersa machine with maximum 610 x 610 mm. “What could have been more obvious than to call on the technological leader for selective soldering? With Ersa technology, every soldering point can be treated separately – in other words with its own parameters – in order to achieve optimum quality,” explains the process engineer responsible at Laudren Electronique. Following relevant tests, the system was designed with a dual pot system for mixed production, since installation it has been ensuring enhanced productivity and quality in 2-shift operation on the manufacturing line.

Convinced by the performance of both the selective soldering system and Ersa Service, the first inquiry for a stencil printer followed about two years later. The first generation was no longer a simple printer; as a multifunctional system it fulfilled further functions and processes along the production line. At the time, those responsible at Laudren Electronique expressed their interest in integrated 3D-SPI – even though this feature was not available on the market at the time. The French knew, however, that the Ersa development department was working on a project to develop precisely this model ready for the market as quickly as possible. For this reason, those responsible at Laudren Electronique decided to purchase a VERSAPRINT S1 stencil printer, which impressed with superior printing and SPI technology for inline manufacturing. Special features of the S1: 100% Solder-Paste-Inspection (SPI), user-oriented interface in accordance with SEMI standard (SEMI stands for Semiconductor Equipment and Materials International), automatic cleaning of the underside of the stencil, optionally retrofittable features.

Following the launch of the second generation of stencil printers VERSAPRINT 2 in 2018, the premium version of which – Ultra3 – had this desirable 3D-SPI function available, it was not long before the existing S1 were retrofitted at Laudren Electronique. This retrofit was carried out directly at Ersa headquarters in Wertheim am Main – with a machine of the type VERSAPRINT 2 Ultra3 loaned to the Laudren team on an interim basis.

How does the integrated 3D-SPI work? Three-dimensional inspection of the VERSAPRINT 2 reliably detects deviations in the volume of solder paste depot by means of laser triangulation – where a laser beam is projected onto the object to be measured, the light reflected by this is mapped under a triangulation angle on the sensor of the camera and the height information is calculated using the geometry of the lens structure. The image is obtained by moving the measuring device over the printed circuit board and scanning the laser profile. The following characteristics are evaluated: volume, area, height, short-circuit, offset. If the system determines deviations in the solder paste printing to the specifications, a 2D image of the area affected is recorded for better analysis through the operator. In addition, the 3D image can be rotated and enlarged as required for safe, efficient analysis. A further advantage of integrated inspection is the closed loop function for the correction of print offset – this is able to detect offset and correct this automatically depending on the direction of printing.