Fluke DATAPAQ SolarPaq User manual

SolarPaq
USER MANUAL
for use with
Issue 1
MA5050A

SolarPaq
User Manual
for use with
Issue 1
Datapaq
®is the world’s leading manufacturer
of process temperature-monitoring
instrumentation. The company maintains
this leadership by continual development
of its advanced, easy-to-use systems.
DATAPAQ PART NO. MA5050A
Europe & Asia
Datapaq Ltd.
Lothbury House, Cambridge Technopark
Newmarket Road
Cambridge CB5 8PB
United Kingdom
Tel. [phone]
Fax [phone]
Email [email protected]
www.datapaq.com
North & South America
Datapaq, Inc.
3 Corporate Park Dr., Unit 1
Derry
NH 03038
USA
Tel. [phone]
Fax [phone]
Email [email protected]
www.datapaq.com

© Datapaq Ltd., Cambridge, UK 2009
All rights reserved
Datapaq Ltd. makes no representations or warranties of any kind
whatsoever with respect to the contents hereof and specifically
disclaims any implied warranties of merchantability or fitness for any
particular purpose. Datapaq Ltd. shall not be liable for errors
contained herein or for incidental or consequential damages in
connection with the furnishing, performance or use of the Datapaq
software, associated hardware or this material.
Datapaq Ltd. reserves the right to revise this publication from time to
time and to make changes to the content hereof without obligation to
notify any person of such revisions or changes.
Datapaq, the Datapaq logo and Solar Tracker are registered
trademarks of Datapaq. Microsoft and Windows are
registered trademarks of Microsoft Corporation.
Manual set in 10 pt Gill Sans.
User manuals are available in other languages;
contact Datapaq for details.
SAFETY WARNINGS
For safe use of Datapaq equipment, always:
•Take care to follow its supplied instructions.
•Observe any warning signs shown on the equipment itself.
Indicates potential hazard.
On Datapaq equipment this normally warns of high
temperature, but where you see the symbol you should
consult the manual for further explanation.
Warns of high temperatures.
Where this symbol appears on Datapaq equipment, the
surface of the equipment may be excessively hot (or
excessively cold) and may thus cause skin burns.

CONTENTS
7 Introduction
9 Basic Hardware and Its Use
9 System Components
9 Thermal Barriers
10 Thermocouple Probes
17 Running a Temperature Profile
17 Overview
18 Preparing the Logger
18 Installing the Logger in the Thermal Barrier
19 Placing the System in the Furnace
19 Removing from the Furnace and Downloading Data
20 Preparing the Data for Analysis
21 Using Hardwired Telemetry
21 Troubleshooting
23 Anti-reflective Coating (Sputtering)
23 Thermal Barrier
24 Thermocouples
26 Running a Temperature Profile
27 Contact Firing (Metallization)
27 Thermal Barriers
28 Thermocouples
30 Running a Temperature Profile
31 Module Lamination
31 Thermal Barrier and Frame
32 Thermocouples
32 Running a Temperature Profile

SOLARPAQ Introduction 7
Introduction
Datapaq
®SolarPaq, incorporating Insight™Solar Tracker®software, is a
complete system for monitoring and analyzing the temperature profiles of
products within a wide range of heat-treatment processes used in the
manufacture of photovoltaic cells. Power and flexibility make SolarPaq a perfect
tool for process-temperature monitoring, from commissioning and
troubleshooting to process optimization, ensuring consistent quality of product
and maximum efficiency.
Insight software’s innovative analysis techniques help in identifying problems,
fine-tuning the process and reducing running costs. Powerful reporting
facilities allow the user to generate customized printouts, including any or all of
the analysis results or raw temperature data.
The materials and procedures detailed in this manual are intended to aid
SolarPaq users in obtaining accurate and repeatable temperature profiles.
Datapaq has developed specific solutions for the most commonly profiled
processes used in the manufacture of crystalline photovoltaic cells, and these
are covered here in some detail. There is also general guidance on the
considerations to be followed when using the SolarPaq system in associated
industries such as the manufacture of thin-film photovoltaic cells.
This manual contains the following sections:
•Basic Hardware and Its Use (p. 9) – An introduction to thermal barriers
and thermocouple probes, their specifications, and use.
•Running a Temperature Profile (p. 17) – The stages of obtaining a
temperature profile that are common to all processes in the manufacture of
photovoltaic cells, including the use of hardwired telemetry to follow the
development of the temperature profile in real time.
•Aspects of using the SolarPaq system that are specific to different processes:
anti-reflective-coating (sputtering) (p. 23), contact-firing
(metallization) (p. 27) and module lamination (p. 31).
The dedicated manual supplied with the data logger should be read in
conjunction with this manual. It provides information on operating the logger,
including:
•Installing Insight and establishing communication between logger and PC.
•Resetting the logger with new data-collection parameters.
•Downloading the collected data to the PC.
•Use of telemetry.
•Troubleshooting logger problems.

For full details on use of the Insight software, refer to the online Help system
available after the software is installed.
8 Introduction SOLARPAQ

Basic Hardware and
Its Use
To accommodate the range of different processes which are involved in the
manufacture of photovoltaic cells, SolarPaq systems are supplied in a variety of
configurations, depending on the intended application. The information in this
chapter applies to all systems. Some processes in cell manufacture require
special additional considerations, and these are dealt with separately:
•Anti-reflective coating (sputtering) processes (p. 23).
•Contact firing (metallization) (p. 27).
•Module lamination (p. 31).
For use of the data logger, and for any further special-purpose hardware,
see the documentation supplied with it.
System Components
A typical SolarPaq system comprises:
•Data logger, with communications lead and charger.
•Data logger user manual (specific to the logger model).
•Thermal barrier – to protect the logger during its time in the furnace.
•Thermocouple probes.
•SolarPaq User Manual.
•Insight Solar Tracker software.
Thermal Barriers
The thermal barrier provides the thermal and mechanical protection necessary
for the data logger to survive in the hostile environment of the furnace.
A range of barriers is available to suit different loggers and different processes,
and the specification and use of a selection of these are described in the
appropriate sections of this manual.
Micro-porous ceramic insulation covered by a ceramic fiber cloth provides the
primary thermal protection, enabling the system to operate at high
temperatures for extended periods.
SOLARPAQ Basic Hardware 9

When used in vacuum processes, and when the barrier has been left standing
for some time, the vacuum may take longer than normal to pump out due to out-
gassing from the ceramic insulation.
Selecting a Thermal Barrier
Before running a temperature profile of a given process, the user must ensure
that the SolarPaq system is suitable.
The thermal barrier used must have a specified thermal duration which exceeds
that of the time/temperature profile to be experienced within the process (see
barrier specifications elsewhere in this manual).
Failure to ensure use of a suitable thermal barrier may lead to the
barrier and/or logger suffering irreparable damage.
The physical size of the SolarPaq system (primarily the thermal barrier) needs
to be considered in order to ensure that it can freely and safely pass through
the process. Particular attention must be given to ensuring that it can be safely
loaded into and recovered from the furnace.
In case of any doubts on the choice of thermal barrier, contact Datapaq with
full details of the process.
Thermocouple Probes
Thermocouple probes utilize the Seebeck effect, discovered in the nineteenth
century, by which an e.m.f. is produced in any electrically conducting material
that is not at uniform temperature. The actual voltage measured is proportional
to the temperature difference between the thermocouple’s ‘hot’ and ‘cold’
junctions (the hot junction being the measurement junction, and the cold
junction being the junction of thermocouple and measurement instrumentation).
The practical implementation of thermocouples requires sophisticated
electronics to eliminate potential measurement errors which include poor
linearity over the measurement range, and inaccuracy due to temperature
variations at the cold junction. To accommodate these the electronics in the
measuring system must simulate a temperature of 0°C at the cold junction, as
well as compensating for any non-linearity over the range of thermocouple
operation.
Over the years, ‘standard’ thermocouples have been developed using materials
chosen for sensitivity, linearity (consistency of sensitivity over the useful
temperature range), price and availability. Current standards include types K,
N, R, S and T, each type being identified by its connector color.
10 Basic Hardware SOLARPAQ

Thermocouple Specifications
The standard thermocouple probe for furnace operation in photovoltaic-cell
manufacture is type K, which has a hot junction combining nickel-chromium
alloy and nickel-aluminum alloy. International specifications for type K define a
sensitivity and linearity over the range 0–1,250°C, though operating range is
limited in practice by the cable insulation (see below).
Probe
Type
Temperature
Range
Cable Insulation Accuracy of Probes Supplied by
Datapaq
K-150°C to 1,370°C Mineral, PTFE, ceramic ±1.1°C (or ±0.4% if greater) at
0–1,250°C
Type K thermocouples supplied by Datapaq are supplied with green
connectors and cables, following the IEC584 color standard.
Thermocouple Cable Insulation
The practical operating temperature of the thermocouple probes is limited by
the cable insulation material’s temperature characteristics. In processes used
for the manufacture of photovoltaic cells, the probe insulation recommended is
primarily mineral and PTFE.
Insulation Upper Temperature Limit
Mineral insulation (MI) 1,250°C
PTFE 265°C
Binder-less glass fiber 1,000°C
Mineral-insulated (MI) probes have an enclosed junction providing increased
immunity to electrical interference, which is particularly useful in sputtering
processes (p. 23). They are less flexible than PTFE, but suitable for use up to
1,250°C.
Binder-less glass fiber provides a very lightweight flexible insulation suitable
for high temperatures. It is used in processes such as contact firing.
PTFE (polytetrafluoroethylene)-insulated probes are suitable for general-
purpose use at temperatures up to 265°C. PTFE is a robust, flexible, non-stick
material, with a low thermal mass and therefore a quick response time.
WARNING
PTFE does not support combustion, but decomposes above 265°C producing small
amounts of toxic fumes.
The important products from PTFE thermal decomposition are as follows.
SOLARPAQ Basic Hardware 11

At Temperatures Greater Than Product
400°C See note*
430°C Tetrafluoroethylene
440°C Hexafluoropropylene
475°C Perfluoroisobutylene
500°C Carbonyl fluoride*, which, in moist air,
converts to the acid gas hydrogen fluoride
* May also be produced if PTFE tape is kept at 400°C for an extended time.
Health-hazard Data
•Inhalation of decomposition products from PTFE can produce ‘polymer
fume fever’, which has symptoms similar to influenza.
•There is no risk from ingestion or skin contact.
•There are no medical conditions generally aggravated by exposure to PTFE.
Emergency and First-aid Procedures
•If there is accidental contact with PTFE fumes, remove the person
concerned to clean air.
•Self-contained breathing apparatus and protective clothing should be worn
when fire-fighting.
Thermocouple Types and Accessories
Ultra-fine High-temperature Thermocouples
Mineral-insulated cable, diameter 0.5 mm. Complies with
BSEN 60584.2 Class 1. Maximum 1,100°C for short
durations.
PA1570 0.3 m/1 ft
PA1571 0.6 m/2 ft
PA1572 1.0 m/3.3 ft
Adhesive-patch Thermocouple
Attaches directly to light-gauge metal or plastic with
adhesive patch and/or high-temperature tape. Ideal where
fast response is required or in infra-red processes. PTFE-
insulated cable. Maximum 265°C.
PA0061 1.0 m/3.3 ft
PA0060 1.5 m/4.9 ft
PA0062 3.0 m/9.8 ft
12 Basic Hardware SOLARPAQ

Binder-less Glass-fiber Thermocouple
1/0.2 flat-pair cable, hot junction flattened for improved thermal contact. Complies with ANSI
MC96.1 Special Limits of Error. Maximum 1,000°C.
PA1144 0.5 m/1.6 ft
PA1145 1.0 m/3.3 ft
Kapton Tape – High-temperature Adhesive
For securing exposed-junction thermocouples. Pressure-sensitive silicone adhesive. Maximum
400°C.
HT0090 9 m/29.5 ft
Working with Thermocouple Probes
Datapaq probes cover a huge range of possible usages. Choose suitable types
for your process, and for the individual probes’ locations, from those listed
above.
The process temperature may determine the choice of thermocouples’
insulation material. PTFE is to be preferred if the temperature of the process is
low enough to permit its use; see p. 11.
The mechanical design of the thermocouple tip (the hot junction) needs to
be suitable for the product to which it will be attached. For measuring surface
temperature of a crystalline cell, a very lightweight flat tip is best. When
measuring the temperature of thicker glass panels, a heavier probe can be used
for greater robustness.
The length of the thermocouples should be selected to ensure that there is
adequate wire to connect the product back to the data logger, but they should
not be so long that excess wire could get caught or trapped as the system
passes through the process.
The thermocouple type (K, N, R, S or T) must match that of the data logger
used.
Probe Location
The product’s geometry and the process’s thermal requirements define the
number and location of the thermocouples required for the test. In some
instances it is necessary to install an array of thermocouples to provide
coverage over the entire area of the product. In others, the thermocouples are
located to monitor a specific part of the product.
SOLARPAQ Basic Hardware 13

Probe Attachment
Attaching probes to the product is a key step in obtaining accurate and
repeatable temperature profiles. There are a number of options, depending on
the exact nature of the product and the temperatures at which it is processed:
•Adhesive tape.
•Adhesive cement, either high-temperature epoxy or ceramic can be used.
•Mechanical attachment using a clamping mechanism.
The thermal mass of the thermocouple tip and of its fixing method must be low
compared to that of the product. This will ensure that measurements are a true
reflection of the product temperature that would occur in normal production.
The tip of the thermocouple probe must be in good mechanical contact with
the product when monitoring surface temperature. Poor thermal contact will at
best result in slowing the rate at which the product heats the probe and at worst
prevent the probe from achieving the same temperature. Ensure probe tips are
clean before attaching.
To assist repeatability and obtain maximum lifetime from the probes, it is
preferable to use as a test-piece a standard example of the product to which the
thermocouples are permanently attached.
Testing Thermocouple Probes
Although thermocouples are generally robust, they can be damaged during
handling. To confirm their correct operation after installation, either:
•Set up the system as if to monitor a profile run using hardwired telemetry
(see p. 21 for details), and note the temperatures registered by the
thermocouples as they are displayed in Insight – or
•Use a type-K digital thermometer, attaching each thermocouple in turn to
the thermometer’s connector – or
•With a full set of thermocouples attached to the logger, and the logger
connected to the PC, open the Diagnostic section of the Communications
Setup dialog in Insight; this shows current probe temperatures.
Proceed as follows.
1. Note readings first at ambient temperature: thermocouples registering no
data in Insight, or an open circuit with a digital thermometer (*OC* in the
Communications Setup dialog), may be broken. Inconsistent readings may
indicate an intermittent short circuit.
2. If a satisfactory ambient reading is recorded, apply heat to the
thermocouple-tip via fingers or other heat source. An increased
temperature should register:
14 Basic Hardware SOLARPAQ

○If the reading does not change, the thermocouple is short circuit and
must be replaced.
○If the probe measures air temperature, the cable may have damage which
has created a new hot junction.
○If the thermometer shows a decrease, the thermocouple connections are
reversed.
3. Confirm correct operation at 100°C by placing the thermocouple-tip in
boiling water.
4. Replace any thermocouples with damaged cables.
SOLARPAQ Basic Hardware 15

16 Basic Hardware SOLARPAQ

SOLARPAQ Running a Temperature Profile 17
Running a Temperature
Profile
The information in this chapter applies to all SolarPaq systems, and should be
read in conjunction with detailed guidance on use of the specific system:
•Anti-reflective coating (sputtering) processes (p. 23).
•Contact firing (metallization) (p. 27).
•Module lamination (p. 31).
A temperature profile can be acquired by two means:
•Standard profiling – After the logger and product have been passed
through the furnace, data is downloaded from the logger into the PC to be
displayed and analyzed by the Datapaq Insight software.
•Using hardwired telemetry – As the logger gathers data from the
product inside the furnace, this is communicated directly to the PC by a
hardwired connection. The temperature profile can be watched developing
as it happens, i.e. in real time. See p. 21.
This chapter describes the basic stages of running a product or test-piece through
the furnace in order to obtain a temperature profile without telemetry.
Overview
Before running your product and the data logger through the furnace you will
use the Insight software to reset the logger, i.e. to prepare it for receiving fresh
data. After the logger has been retrieved from the furnace, you will use Insight
again to download the profile data and save it to disk. The stages are as follows.
•Choose positions for, and attach, the thermocouple probes.
•Setup communication between the data logger and your PC (if this has not
already been done for a previous profile run).
•Reset the data logger so that it is ready to receive fresh data; in the process
of doing this you will also be able to set the sample collection interval and
the method used to trigger the start of data collection, and to check the
logger’s battery status.
•Install the logger in its thermal barrier.
•Run the test-piece and logger/barrier through the furnace.
•Download the data from the logger into the Insight software.

18 Running a Temperature Profile SOLARPAQ
•If necessary, set the furnace start position within the data.
•Add any additional information that you wish to have recorded with the
profile data.
After this, Insight can be used to analyze the profile data as required.
Preparing the Logger
If the data logger is being connected to a PC for the first time, it is necessary
to enable communication between them. The logger must also be reset before
a profile run – using Insight software – to establish its data-collection
parameters. See the dedicated user manual for your logger, or Insight’s Help
system.
Note that the logger’s recommended sample interval (selected during the reset
process)differs according to the process being monitored. See the relevant section
of this manual.
If there is any doubt that the logger’s battery charge may be inadequate for the
profile run, this must also be checked by using the reset procedure.
For the procedures involved, see your dedicated logger manual or the Insight
Help system. Note that, since its last use, the logger must have cooled below 35°C
(comfortable to hold without gloves).
Installing the Logger in the Thermal
Barrier
Ensure the thermal barrier has cooled sufficiently since its last use.
1. Plug the thermocouples into the logger’s numbered sockets. If you are using
a process file, ensure that the probe/socket numbers on the logger
correspond to those used to define probe numbers and locations in that file
(see the Insight software for an introduction to process files: press function
key F1, or select Help > Contents from the menu bar, and click the section
‘Process Files: Furnace, Recipe, Product’).
2. Ensure the barrier’s seals are clean and undamaged. A good seal between
thermal barrier and thermocouple cables is essential if the data logger is to
be protected. Ensure that the thermocouple cables do not cross over
where they exit the barrier, as this will ensure the best possible seal when
the barrier is closed.

SOLARPAQ Running a Temperature Profile 19
3. If the trigger mode is Start Button, press and hold the start button for
about 1 second until the green LED starts to flash.
4. Close the thermal barrier, ensuring that the lid is securely fastened.
Placing the System in the Furnace
Line speed through the furnace may be very high, so care must be taken to
prepare everything before loading any part of the system into the process. It is
often the case that access space, and access time, at the entrance to the
process are limited, so plan how you intend to install the system.
1. Place the instrumented test-piece onto the furnace’s conveyor or loading
mechanism with the thermocouple cables towards the rear, ensuring that
the assembly is positioned such that it will not foul any part of the furnace
as it passes through. In most applications, the best results are obtained if
the test-piece enters the process before the thermal barrier, ensuring least
thermal disturbance as the product temperature measurements are taken.
2. If the system will be in the process for a long time, note the time at which
it entered so that the expected exit time can be calculated.
Removing from the Furnace and
Downloading Data
WARNING
The thermal barrier – and possibly the logger – will be hot. Use protective gloves.
Recover the system as soon as it exits the furnace – or at the first opportunity
that access to the system is feasible and safe. Sufficient space must be available
near the furnace to allow appropriate handling procedures.
Open the thermal barrier and remove the logger.
Failure to remove the logger from the hot thermal barrier could damage the logger.
Opening the thermal barrier fully and placing it on a cold surface will increase
its rate of cooling.
If the setup permits, the thermocouple probes can be left in place for
subsequent profile runs. Leaving the thermocouples in place will reduce wear
and cable stress and so maximize their life.
If it is necessary to stop data acquisition manually, press and hold the
logger’s red stop button until the red and green logger-status LEDs are on

20 Running a Temperature Profile SOLARPAQ
simultaneously. A red logger-status LED flashing every 5 seconds indicates data
stored in the logger but not yet downloaded to the PC.
Download the data from the logger to the PC using the Insight software. For
the procedures involved, see your dedicated logger manual or the Insight
Help system (on Insight’s menu bar, select Help > Contents).
Preparing the Data for Analysis
For full details of Insight’s powerful analysis capabilities, see the online Help
system: on Insight’s menu bar, select Help > Contents > Data Analysis. Before
starting full analysis of the downloaded data, it may be advisable to:
•Apply a process file (see the Insight software for an introduction to
process files: press function key F1, or select Help > Contents from the
menu bar, and click the section ‘Process Files: Furnace, Recipe, Product’).
•Specify the furnace start position in the data (see below).
•Apply thermocouple correction factors to the data (see below).
•Record any notes specific to the profile run (see below).
Specifying Furnace Start
If you have not applied a process file to the data during download (see above),
or if the process file you applied did not specify that the furnace start
position be adjusted, you may want to adjust the furnace start position now:
from the menu bar, select Process > Adjust Furnace Start, or use the right-click
menu.
This can be valuable as it permits different paqfiles, i.e. data from different
temperature profile runs, to be compared with each other. If you do not wish
to adjust the furnace start at this point, you may still do so at any time
subsequently.
For an explanation of furnace start, and how to adjust it, click Help in the Adjust
Furnace Start dialog.
Thermocouple Correction Factors
It is possible to increase accuracy by using calibration data for the
thermocouples to establish correction factors. If correction factors are known
for a range of temperature values, and if a linear relationship is assumed
between adjacent temperature values, appropriate corrections can then be
applied to all data within the calibrated temperature range. Insight stores these