Durable energy supply systems for electronics production positioning systems

Quiet, low-vibration, low-abrasion energy supply systems for cleanroom applications

Smartphones are booming. They become more powerful with each generation. The core of a mobile power pack is a printed circuit board or card made with a laser imaging system. The high-precision machining process is performed reliably with the help of sophisticated positioning systems. Pre-assembled energy supply systems ensure the necessary long-term operational reliability, smoothness of operation, and low vibration and abrasion that is mandatory for cleanroom manufacturing.

Profile

  • What was needed: energy chains from the E6 product range and energy chains from the E3 product range as fully harnessed readychain systems
  • Requirements: continuous operation of the system 24 hours a day, seven days a week requires high availability; Low vibration and low abrasion are crucial for a trouble-free and flawless manufacturing process
  • Industry: mechanical engineering, laser imaging systems
  • Success for the customer: energy chains from the E6 and E3 product range are suitable for cleanrooms, operate smoothly, are therefore particularly low-noise and low-vibration and offer almost complete freedom from wear; the pre-assembled readychain systems considerably reduce the project planning and pre-assembly work for the customer
Other products for machine tools
Energy chains Energy chain on the Z-axis. It is exceptionally low-vibration and quiet.

Problem

In the production of smart phone circuit boards, a special exposure principle using laser technology can now achieve a significant increase in throughput compared to the past. At the same time, manufacturing costs drop significantly: important arguments in the mass production of electronic equipment.
Jenaer Antriebstechnik GmbH supplies precisely these exposure and laser structuring systems, which are later installed as mechatronic subsystems in the respective frame systems. 
Today, approx. 140 circuit boards can be exposed per hour. At least 30 smart phones are assembled with individual circuit boards with different circuit functions from an overall circuit board, a so-called panel. The continuous operation of these systems places a particular stress on all machine components. Thus, the highly complex facilities are in operation 24 hours a day, seven days a week. A plant standstill is therefore expensive and simply must not occur. Although the actual  manufacturing conditions are unproblematic, the long service life makes robust and reliable components essential in the subsystem as well.
An essential component of the system is the exposure table. It has a size of 27" x 27". After loading, the PCBs are exposed to light. The table is lowered, transported to the back and unloaded again. In the meantime, a second table has been loaded. The exposure process starts again. It is important for the scanning process that the movement is completely smooth and jerk-free so that there is no interference when printing on the PCBs. For the energy supply solution, this means that it must operate absolutely uniformly and quietly at the same time. In addition to the uniform motion profile and smooth running, low vibration and low abrasion are crucial for a trouble-free and faultless manufacturing process.

Solution

For the safe guidance of the drive, measuring system and compressed air cables as well as other media in the positioning unit, completely pre-assembled energy supply systems from igus are used, including strain relief, connectors, guide trough and mounting plates. The main advantage of the so-called readychains is that they considerably reduce the project planning and, above all, the installation effort.
While two particularly quiet energy chains from the E6 product range prove their strength on the Y-axis over a length of approx. 2m, the highly flexible energy chain from the T3 range demonstrates its efficiency on the Z-axis over a length of just under 400mm. Both systems are suitable for production under cleanroom conditions, which also prevail during the exposure of the printed circuit boards, and which is why virtually no abrasion is permitted to be generated.
The E6 energy chain system is particularly low-noise and low-vibration, which fits perfectly with the low-vibration drive concept of the linear motors in this application. It minimises the so-called polygon effect which can occur during the rolling motion of the energy chain. Since there must only be a maximum of 2µm between the target and actual positions, absolutely uniform running is required. In this application, with an inner height of 40mm and a bend radius of 63mm, all cables are safely guided on the Y-axis.
The T3 energy chain system is used on the Z-axis. It also combines smooth operation with low noise. Added to this is the ease of assembly. The side bands which snap together, replace a conventional pin/bore connection and prevent relative movements between the joints giving extremely low wear. This means virtually no wear or abrasion, which enables them to be used in cleanrooms. The novel geometrical shape of the t-band, means that hardly any polygon effect is generated in operation. It operates very harmoniously and smoothly and is therefore particularly low-vibration and quiet. Due to its low mass, the solution is suitable for applications with low fill weights and short strokes, combined with high speeds and accelerations.
 
Energy chains E6 energy chain system without classic pin/bore connection. It is currently the quietest and lowest-vibration solution in the entire igus® energy chain range.
energy chain The energy supply systems are supplied pre-assembled. There is little space available. In addition, there are tight bend radii.

Advantage pre-assembly

Due to the diverse experience of Jenaer Antriebstechnik GmbH, the automation expert originally relied on its own cable concept. However, due to the high customer requirements, the original solution was then tested in comparison in the test laboratory with chainflex cables from igus. The endurance test clearly spoke in favour of the igus product, especially with regard to cleanroom suitability. For this reason, it was decided to purchase not only the energy chains but also the pre-assembled cables from a single source. This also reduces the throughput in production.
The special requirements for core cross-section combinations and bending resistance as well as cleanroom suitability speak in favour of chainflex cables from the standard range, which can, however, also be adapted to customer requirements if necessary. Added to this in this application are their relatively high number, the tight bend radii, the small space available and the low abrasion. Furthermore, they must not influence each other in order not to impair the functionality of the entire system in the long run.