Perfect Line - Arnold Gruppe

Production & Inspection Production Technology Germany
Especially in the wafering
process, the adhesive
must fulfill two basic
requirements: high
strength and temperature
resistance during the
wafer cutting process
and a universal behavior
during de-bonding of
the cut wafer from
the wire saw beam
with either tempered
water or weak acetic or
lactic acid.
always keeps the adhesive homogeneous. It
is, therefore, always enough adhesive glue in
the system─even in case of changing
containers─and thus allowing continuous
production. There is no need to maintain rest
quantities in the container during container
change nor is it necessary to drain material
supply hoses. The additional material savings
of expensive adhesive substrate is a
considerable side effect.
The adhesive dosing system requires extremely
low maintenance, is flexible and
scalable for different requirements. Within a
few minutes, a simple and fast exchange of
the complete mixing head including the dosage
unit is possible. If necessary, a fast
change of the adhesive medium is possible.
The system may be operated with two cartridges
for 950 Cubic Centimeters (ccm)
each, which corresponds to a total of 1900
ccm. This is beneficial for small to medium
volume production. For example, this is suitable
for a production volume of 100 megawatt
with only one cartridge exchange required
per day. An enormous advantage over
conventional cartridge systems which
require─based on the identical production
volume─up to eight cartridge changeover
cycles per day. In case of large serial productions,
it is recommended to operate with
cost-effective container material with approximately
30 liter material content. In automated
bonding process there are savings
of at least 50% in glue consumption compared
with manual glueing by using larger
containers and linear reduction of the consumption
through the automatic application
of adhesive.
Fully Automated and Reproducible Glueing
The robot in the glueing system is programmed,
controlled and coordinated by intelligent
software tools. With the new developed
software tool AEPS (Arnold Easy Programming
System), customer’s own system
operators are now in the position to create
84
and edit movement and also process parameters
within the robot and glueing controller
intuitively to a certain admissible extent by
themselves (Photo 5). Expert knowledge
about the robot and PLC programing is not
required.
This software tool allows the optimization
of the characteristics of the adhesive bead,
changing of the robot velocity during adhesive
application, editing of the glueing bead
position as well as changing the bead thickness
and other parameters. Simply and safely
by just selecting the required position at
the central touch screen, process or movement
data can be added, deleted or edited.
But even more intuitive programing functions
are available via the Human Machine
Interface (HMI). These adhesive-specific
data include, for example, the required mixing
ratio of the two components, basic geometry
data of the wire saw beam and glass
plate, setting of the required distance between
brick pieces on the wire saw beam;
extended service functions such monitoring
the remaining amount of adhesive within the
system, adhesive-aging supervision, container
changeover cycles, status indication for all
system components, failure analysis and
many more.
The AEPS software tool simply can be
operated directly at the glueing system (System
OPC), or offline at any Windows-based
office-PC. The operator or the process expert
is able to adapt the adhesive process to
the changing production requirements without
time and effort. Program and process
changes are monitored automatically, thus
ensuring the traceability of changes.
By means of the process analysis tool
ARPAT (Arnold Remote Production Analysis
Tool), process data are collected within
the running production in real time, visualized
and recorded. These include not only
quality-related production data, but also machine
parameters and measurement data,
error messages, etc. In addition, there is an
interface for data transfer to higher-level
process control systems (SCADA, MES,
etc.).
Thanks to the wide variety of functionalities
of ARPAT, operator and quality control
department will receive important process
and production data. Based on data received
from the dispense unit during the adhesive
application, ARPAT creates a standard process
protocol from the actual processed part
but also provides diagnostic data in respect
to the dispense process from earlier process
cycles up to a period of minimum four
weeks in the past. For example, continuous
monitoring of the actual material pressure in
the dosing system prior to mixing can indicate
correct material feeding of the two components
but can be also an indication of material
blockages or even air bubble inclusions.
Based on the actual motor speed, the
correct material flow including the correct
mixing ratio during application can be monitored.
By counting all motor revolutions of
the doser during automatic glueing, the applied
material volume per brick is calculated.
For quality tracing purposes, there is
even the possibility to secure an image of the
bead of adhesive applied per brick.
The storage of process data, for example
material flow, pressure, etc., also serves the
purpose of later process analysis. Within a
closed loop of data receipt, data analysis and
parameter change, the operator or process
expert can react quickly as soon as changes
appear. Specifically for sensitive processes
like glueing, this appears to be extremely
important since batch-related material
changes, adhesive aging, and other changing
conditions will always require some handson
system for improvements. Thanks to
ARPAT and AEPS, this becomes an easy
task without expensive assistance from often
only externally available robot, or programing
specialists.
Small Cause a Big Effect
The level of automation in the wafer production
is already very high. With the aim to
reduce the costs while improving quality and
yield, upstream processes must also be reconsidered.
Solutions of highly automated
adhesive glueing systems are already existing
and an essential factor for optimization
of the Total Cost of Ownership (TCO). The
example of a 100 MW plant makes abundantly
clear that the investment is worthwhile
in an automated adhesive glueing system.
The enormous reduction in the glueing
material and labor costs combined with a
significant increase in yield by approximately
three percent show total savings of approximately
US$1.1 million based on a calculated
wafer price of US$1.20. The investment
in an automatic glueing system pays
for itself in less than a year. But critical to
sustainable success is not only a well-balanced
automated system equipped with
high-quality system components for each
process step and a high flexibility to ever
changing conditions, but also the ease of use
by locally available personnel.
Dipl.-Ing. Wolfgang Schürgers, Member of the
Board of the Arnold Group (www.arnold-gruppe.
de), is responsible for sales and marketing. Schurgers
has 28 years of international successful
experiences in the fields of automation, robotics
and glueing processes in the automotive and
photovoltaic industry. Within the range of responsibility
of Schürgers, Business Development
at Arnold Group, the automated glueing process
is considered as key technology in automated
brick processing lines.
REFERENCES
1) International Technology Roadmap for Photovoltaics (ITRPV.net), Results 2010; 4.1.2,
Material Cell Processing
June, 2012