In the DS Merlin, numerous complex processing workflows could be implemented in space-saving design.

Picture credits: Beckhoff Automation

Customer-specific I/O Level Promotes Highly Efficient Machine Construction 

Mühlbauer GmbH & Co. KG based in Roding, Germany, builds specialized machines used in the fields of chip card and passport production as well as in the semiconductor industry. The EJ series EtherCAT plug-in modules, in conjunction with a customer-specific signal distribution board, ensure significant reductions in errors and the time required to manufacture machines. This also results in reduced manufacturing costs and accelerated delivery times for the new DS Merlin die-sorting system.

Martin Dimpfl, Head of Electronic Engineering in the automation division, explains: “The automation division at Mühlbauer focuses on machines for semiconductor finishing, RFID and tag manufacturing, ID card and passport production, personalization machines for documents and bank cards, as well as complex inspection systems. This includes the new DS Merlin die-sorting system, which can process up to 30,000dies per hour – including complete vision inspection for possible defects. 

In addition to the considerable increase in throughput from 20,000 to 30,000chips/hour, simplified machine setup and operation, as well as improved wafer handling, it was also possible to reduce costs by 20 percent compared to the previous machine model. The standardization of the I/O system with EtherCAT plug-in modules from Beckhoff was a key contributing factor to these achievements.

The DS Merlin can process microchips up to a size of 0.2 x 0.4 mm and a thickness of 80 μm with maximum precision and speed. The respective wafer is measured, and the placement or size of the individual chips is recorded. The machine then automatically corrects the transfer of the semiconductor devices to the individual pick-and-place units. The advantage, Dimpfl says, is that “up to now, all this had to be implemented by the machine operator via teach-in. This whole effort has been eliminated.”  

With up to 30,000 dies per hour, the DS Merlin die-sorting system from Mühlbauer can process significantly more semiconductor components than its predecessor model.

Picture credits: Beckhoff Automation

Modular And Compact Machine Designs 

The machine is divided into different function modules. The automatic wafer changer first transports the wafer onto at able and then transports the processed semiconductor wafers back into a wafer cassette. The wafer table expands, rotates and moves the wafer during production. It then positions the wafer in such a way that the following die ejector (chip removal unit) can transfer the individual microchips to the upper of two inspection wheels, where the wafer film is held in position by a vacuum around the die ejector needle. All six microchip sides are 100 percent checked on the two inspection wheels. A counting module then positions, transports and seals the belt with the chips placed in it with the cover band and carries out final inspections. Once the desired quantity has been reached, the belt is cut off. 

This advanced machine was designed to be highly modular and compact, says Dimpfl. “For this reason, four different signal distribution boards with EtherCAT plug-in modules are used in the DS Merlin, for example. The main reason for introducing the new I/O concept was the significantly reduced wiring effort. This has a very positive effect on error reduction and, above all, on manufacturing time and costs. 

Maximum I/O Installation Efficiency Using EJ Modules And Custom-designed Boards

The four signal distribution boards are precisely matched to the Mühlbauer machine’s requirements and, according to Martin Dimpfl, go far beyond simple I/O signal distribution. In addition to the EJ modules, EtherCAT Servo Drives for piezoelectric and piezo-ceramic motors, flashlight controllers and logic for vision applications, as well as the complete 24/48 V voltage distribution are also included. A total of 26 EtherCAT plug-in modules are used, with digital and analog inputs/outputs as well as an incremental encoder interface, stepper motor module and bus power supply unit. “Our goal was to minimize the wiring effort within the machine and to place the signal distribution board as close to the respective components as possible. This results in an extremely compact design, and the complete wiring and testing of the unit can be carried out in the pre-assembly phase. Thus, the times for testing, production and commissioning are reduced throughout,” Dimpfl points out.

“With the comprehensive product portfolio from Beckhoff, the right control solution is available for every machine process. In addition, EtherCAT plug-in modules add another advantage to the time savings and error reductions mentioned above. Through consistent support for EtherCAT communication, they can be easily combined with the wide range of available EtherCAT Terminals. This increases our flexibility immensely, as additional customer requirements – such as the integration of special sensors or special test systems – can be implemented quickly and easily based on the same basic machine,” Dimpfl summarizes. The signal distribution board can also be designed and manufactured in-house by the customer, as a service from Beckhoff or via a third-party company.

Advantages Even For Small Series Production Starting At 10 Machines

As a specialized machine manufacturer, a modular system is indispensable for Mühlbauer because this is the only way to achieve the necessary standardization needed to use basic assemblies efficiently in different machine types, and to eliminate the need for a complete redesign for each machine. Martin Dimpfl explains: “According to our calculations, the use of EtherCAT plugin modules – including the development of the signal distribution board –already returned the investment for a small series of around 10 machines per year. As the functionality of the boards is fully tested in advance, we achieve an enormous reduction of the error rate during assembly, resulting in smooth commissioning. In the case of the DS Merlin, this saves approximately 100 hours of installation time, plus additional time saved that was previously spent on troubleshooting and debugging. Accordingly, we will successively convert all relevant machine types in our portfolio in the future, which comprises more than 200 systems with more than 10machines per year, to the Beckhoff EJ system.”  

The EtherCAT plug-in modules from the EJ series can be used in combination with the appropriate signal distribution board to efficiently implement application-specific I/O systems.

Picture credits: Beckhoff Automation

ABOUT THE AUTHOR:

STEFAN ZIEGLER 

Marketing Communications, Beckhoff Automation