Sunday, June 24, 2018
Publication Date: 02/1/2008
Archive >  February 2008 Issue >  Special Feature: Components and Distribution > 

Dispensing Robots: EMS Providers' Right Hand
The I&J7400 is the largest dispensing robot in the current desktop robot series.

These days, the decision to justify automating a dispensing application is in itself automatic. Even with emerging industrial markets and low labor costs in the BRIC nations (Brazil, Russia, India and China), automation has become the first logical route to low cost quality assembly.

Automation Comes First
Automation is now the first consideration because of quality demands and competition. Until about two years ago, outsourcing meant exporting manual bench assembly to a lower cost manual labor pool. The outsourcing paradigm remains, but it's not always to a lower cost assembly bench, but instead to a lower cost engineering source. Dispensing automation can be simply categorized as three types of process: Bench or Desktop, Conveyor-Line and Assembly-Cell configurations. Several conveyor-line installations require extensive sophistication in vision recognition, in-process sensing and reporting — features that result in a higher cost that has offset any potential price reduction over the years. However there has been a quiet revolution in modular robot designs and extensive cost reductions have allowed global companies to economically install dispensing robots for conveyor-line and assembly cell applications.

Conveyor-Line vs. Assembly-Cell
The improvements in design and the significant cost reductions in Gantry Cartesian and SCARA type robot arms have also introduced ease of programming without any major training for their programmers. Robots have become "products-in-a-box." It is now possible to select a robot simply by the dispensing area required then bolt on the dispensing equipment and connect a simple PLC (Programmable Logic Controller) to integrate a conveyor or assembly cell controlled process.

The improvements provide opportunities for system integrators that can provide prompt turnkey solutions at a fraction of the costs that would have been charged several years ago.

Benchtop Dispensers
But the major change in assembly has been the Bench Dispensing Robot. The humble assembly bench has adopted a new role, a flexible location for automatic or semi-aautomatic assembly that can also provide economic solutions for short runs or constant medium production together with a proving area for new products.
The largest stock sized gantry robot is the I&J9000 automated dispensing series.

The bench is still very much with us and will be for many years to come — but the bench assembly process has become partially automated or automated with an attendee. An operator may either control the process or divide duties between automation and manual assembly.

A primary segment of the assembly process that is naturally designated for automation is dispensing. Dispensing beads or dots of any kind of fluid is impossible to control manually and if it isn't automated, the assembly process will invariably be compromised, resulting in rejects, rework and the inevitable product degradation. In the past, justifying the cost of automating a bench dispensing application over dispensing manually was made difficult by what had been the high capital cost of automation. This is no longer the case, and today it is more difficult to justify not automating.

Pneumatic or any type of hand dispense controllers require an operator to place the tip at the right point or, in the case of a bead, to control the position and momentum of the tip movement. Trying to manually maintain the tip where it should be and controlling the motion at the same time is uncertain, if not impossible.

But these handy dispense controllers may be used with a robot that can accurately measure the position and motion, and the controller simply takes care of the air pressure controlling a syringe or a valve. Therefore when upgrading to an automated system, the existing bench dispenser can be used with the robot, a valve and any bulk feed system.

Size Is Everything
Not so long ago a robot had to be large to be considered a "real machine". Only the Japanese and baby boomers thought that down-sizing was important. In today's industrial climate, global companies now realize that compact machines are invaluable for bench automation.

One industry that particularly takes advantage of compact size, flexibility and precision is medical device manufacturing. The medical industry is vast in its scope and incorporates many independent disciplines for device manufacture, which is unlike the electronics assembly industry where each EMS is probably a mirror of its peer. At present it's unusual to see a bench robot in an EMS for anything other than solder mask or a short run project, but in the world of medical electronics, many high-value projects are performed using bench-type devices. It has been predicted that the interest in EMS companies in involving themselves in the medical arena will probably result in an increase in more flexible assembly solutions to service the higher value demands.
The TMB200 & TMB300 SCARA robotic arms are high speed dispensing and assembly robots, which are servo driven.

Plasma treatment is yet another growing technology using compact bench robots to treat high value products prior to a process. Many medical processes are considered proprietary and highly sensitive. The result is that the majority of companies do not wish to see their techniques documented, but many of these applications have taken advantage of the low cost of benchtop robots.

The role of the bench robot has only just begun to be recognized in other sectors, and any company still using a manually operated dispensing and assembly system will change its procedure once their current production needs have been properly evaluated.

The decision to automate the bench is less obvious than with a conveyor-line system where the robot is the likely focus of the assembly operation; but when making an overall appraisal of the manufacturing process, there will always be a bench operation that is either held hostage by an irreplaceable skill-set or a built-in complacency about the process itself.

Once the decision has been made to investigate a manual system, most probably due to some catastrophic breakdown of the assembly process or the difficulty in obtaining or retaining skilled workers, the automation implementation will be comparatively straightforward. Controlling outsourced assembly is assisted by automating the process as much as possible, while methodology can be worked out by the OEM customer. Reducing manual intervention reduces potential errors introduced by differing levels of skill, hygienic care and training.

Automating the dispensing part of the process gets high marks for eliminating the possible causes of product degradation and failure. Most products have some kind of dispensing element in the process. In all but the most unusual assembly processes, this part of the manufacturing cycle should be automated.

There is little reason why an operator should have to struggle to continue to provide a perfect dot, a uniform bead or an accurate fill and be blamed for not succeeding. Whether it's a domestic or outsourced situation, there is a simple solution and it will invariably result in better products at lower cost.

For more information, contact: I&J Fisnar, Inc., 2-07 Banta Place, Fair Lawn, NJ 07410-3002 201-796-1477 fax: 201-794-7034 E-mail: Web:

search login