Essemtec doubles dispensing speed and accuracy [Sep 2011]

September 26, 2011 10:17 am

Essemtec, one of the global leaders in manufacturing of highly flexible surface mount technology (SMT) production equipment introduces the new Scorpion automatic dispensing system. The machine is built on the Paraquda machine base, which enables highly accurate dispensing and performance of up to 100’000 dots per hour. The machine can be equipped with up to four different dispensing valves and is designed for flexible and productive dispensing in electronics manufacturing, LED assembly and other industries.
New machine base increases speed and accuracyThe Scorpion can dispense up to 100’000 dots per hour with an accuracy of ±25 μm (3s). The exceptional performance is achieved due to the new dispenser base, the Paraquda machine platform. Its XY-portal is built on a robust mineral cast chassis that provides excellent damping and smooth motion at high speed. The H-Drive features precision linear measuring devices to guarantee highest accuracy for demanding tasks.  The XY-drive is so powerful that it can move up to four independent dispensing valves simultaneously. This minimises changeover time between different applications and allows multiple media to be dispensed in one run.
Twin Dispensing: Simultaneous Operation Saves Time The Scorpion implements a twin dispensing mode for the production of high volumes. Two valves can dispense simultaneously on two different locations, the distance between the valves is adjustable.
Typical twin dispensing applications include LED manufacturing and electronics assembly with multiple printed panels. When the distance between two panels is constant, two jet valves can apply glue dots simultaneously. Twin dispensing can double throughput for such applications. Freedom of MotionThe working range of the Scorpion is bigger than most other dispensing systems. The dispensable area is specified at 650 x 500 mm (25.6 x 19.7″) for a standalone machine and 510×470 mm (20×18.5″) for inline machines. However, the working area can be used flexibly and can be equipped with customer-specific substrate holders.
Each of the dispensing valves (maximum of four) is equipped with an independent, highly accurate C-drive with an 85 mm stroke (3.34”). As such, the Scorpion can dispense on multiple levels, and it can dive into cavities or vault over components.
Any Metering Valve Almost any kind of dispensing valve can be used with the Scorpion. Standard valves include time-pressure, archimedean screw and piezo-flow-valve for solder pastes. The ideal valve for an application is determined by the user or by process specialists.
The maximum performance of the Scorpion is achievable with Jet valves that allow drops to be shot over several millimetres and, therefore, does not need vertical motion. The Jet valve recommended by Essemtec provides a wide application range. It dispenses liquid media and highly viscose pastes as well as filled adhesives or cyanacrylates.
 The Jet valve solves many otherwise difficult dispensing tasks. It even can dispense continuous lines by placing dots close to each other. Large and small volumes can be altered, which is not feasible with other valve types.
Needle distance control with laser sensorFor a Jet valve, the distance to the substrate generally is not important. When dispensing with a needle, however, the distance between the needle and the substrate is one of the most important process parameters. If the substrate is warped, a constant distance must be guaranteed. For this, Scorpion includes an accurate, fast regulation system.
A high precision laser sensor scans the substrate prior to dispensing with an accuracy of 1 μm. During dispensing, the position of the dispensing head is automatically corrected and follows the surface.
One of the Scorpion’s extraordinary features is the automatic needle calibration system that measures the needle length with an accuracy of 1 μm. This feature simplifies needle exchange and increases process reliability.
The innovative cleaning station for dispensing needles and Jet valves ensures good conditions for quality dispensing. The device uses only vacuum for cleaning and is more reliable than traditional mechanical cleaning systems.
Simple for Operators, Flexible for SpecialistsThe graphical user interface of the Scorpion makes setup and production easy tasks for the operator. The process specialist, however, can still influence all dispensing parameters and can fine tune the dispensing process as desired. Programming is possible by teach-in, by importing coordinates or using pick-and-place data.  Proven system with potential for the futureScorpion Dispensers are available beginning August 2011. The machine, however, has been in practical use for months already along with the Paraquda pick-and-place, which is the base of the Scorpion Dispenser. It has proven its reliability in many electronics production facilities worldwide. l