Micro Dispensing Techniques

Micro dispensing is the technique of producing accurate and repeatable liquid media dosages in volumes of less than one micro-litre. The continuing miniaturisation in almost all technical areas creates constant challenges for industry, research & development facilities. Micro dispensing is one of those challenges. Ever smaller quantities of adhesives, liquids, oils, greases and a multitude of other media must be dispensed reliably and accurately in both dose volume and positional placement within the shortest cycle times possible.

Dispensing Techniques

Basically there are two different dispensing techniques - The classic Contact Dispensing and the latest Non-Contact Dispensing.

Contact Dispensing

Contact dispensing is as old as dispensing itself where there is the application of small amounts of a material supplied from a suitable container, at certain positions on a work piece. A good example for this is in applying adhesive from a tube. To transfer the adhesive, it requires contact between the tip of the tube and the part onto which the adhesive has to be deposited.

Typical problem areas with this type of dispensing method are....

Relatively slow dispensing
Part has to be contacted
Part could be damaged during contact
Adhesive forms threads on separation from part causing mess
Adhesive is not in the expected place
Adhesive dispense quantities can vary and are difficult to reproduce (big variation)

Despite of these disadvantages, contact dispensing is still used in the majority of automated processes today.

The reasons for this are....

Lack of knowledge regarding non-contact dispensing technology & systems
Few manufacturers of non-contact dispensing systems
No direct access to dispensing area on part (e.g. undercuts)
Material not suitable for non-contact dispensing

Non Contact Dispensing (Jetting)

Due to increasing demands for shorter cycle times and higher accuracy in almost all areas of production, non-contact dispensing is gaining ever increasing popularity. A good example for this application is the attachment of very small electronic components (SMD parts) onto printed circuit boards and substrates. In such cases, the component carrier needs to be positioned in one plane only, so that the adhesive can be transferred without contact.

These examples demonstrates the advantages of non-contact dispensing....

Elimination of a feed motion of the part (saving of process time)
Rapid ejection of the adhesive (saving of process time)
No contact with the work piece (no damage or mess)
Even application of adhesive independent of part topography and surface structure

Suitability Of Materials To Be Dispensed

With the appropriate experience and know-how in dispensing, a large number of materials can be dispensed with the non contact method.

To assure the suitability of your material for non-contact dispensing, we offer you a comprehensive consultation and initial material dispensing test - all free of charge.

Benefits of using Liquidyn Dispense Valves over Piezo Dispensing Systems

Liquidyn systems utilise a simpler technology compared to Piezo Dispensing Systems, which means that…..

Liquidyn Dispense Valves are much easier & simpler to use
Liquidyn Dispense Valves are more flexible to use (i.e. easy for the customer to adapt the valve himself to the process)
Liquidyn Dispense Valves are more robust than Piezo Valves – The more complicated, the more things that can go wrong !!
Liquidyn Dispense Valves are easier to trigger yourself - they can be triggered directly from a suitable PLC or through a V10

For all these reasons the Liquidyn is a more cost effective and optimised solution for precision micro dispensing application.
 

Do you have an application for Micro Dispensing - if so, please complete our on-line enquiry form by clicking here