fischerscope

No.
12
01
10/09
FISCHER NEWSLETTER
Coating Thickness
Material Analysis
Microhardness
Material Testing
«editorial»
«closer examination»
Dear Readers,
Fischer spreads its involvement
with education institutions
in SEA
Once you have read this issue of
FISCHERSCOPE, you will realise that the
main focus of our efforts is rising to the
challenge of new measurement tasks.
Our new portable X-ray fluorescence
instrument enables you to make measurements on large objects. FISCHER has implemented a new concept in the development
of this instrument: a fully-fledged X-ray
device with extensive functions in a mobile
format.
For microscopic specimens, there is progress in the measurement of extremely
small structures in semiconductor technology. And in the inline measurement
sector, IfG has developed an X-ray diffraction method that can determine the
concentrations of various phases of an
element in powders.
Other innovations presented in this issue
are long-term nano indentation and a new
generation of conductivity meters.
Finally, I am pleased to introduce our worldwide service organisation and what they
offer.
We hope you enjoy reading this issue!
Walter Mittelholzer
CEO
Helmut Fischer Holding AG
Helmut Fischer AG
This year Fischer starts activities in Malaysia with seminars in Malaysian Higher
Institution of Education, the first of the series involved Multimedia University
with campuses in three locations in Malaysia and a student population of about
20,000 undergraduate and post graduate students. MMU’s is a highly ranked local
Technical University with strong links to Telekom Malaysia the government linked
telecommunications services provider, key research and development subjects
that MMU is involved in other than telecommunications, is radar, image processing,
metallurgy, material science. There was keen interest expressed by Professor
Koo of Multimedia University on Automation of Measurements, material analysis
and analysis of contaminants. A total of 40 students both under graduates
and postgraduates with 5 staff members attended the seminar conducted
where Fischer show cased pattern
recognition and various automated
measurement knowhow. A lively
discussion after the presentation was
held with staff members and postgraduate participants on possible
collaborative work and measurement
methods, subjects of key interest was
possible usage of some of Fischer’s
measurement technology to be integrated into measurement systems
that MMU does customise for local
industries.
«information from practice»
The new FISCHERSCOPE® X-RAY XAN® 500:
mobile coating thickness measurement and
material analysis from FISCHER
the mobile benchtop unit (Figure 2) under all conditions. The
hand-held unit can easily be detached from the benchtop unit
(see Figure 3) to measure large objects or take measurements
in awkward places. It is shaped for reliable placement on the
specimen to facilitate reproducible measurement of coating
thickness or material composition.
1
2
3
4
5
X.
S
Cr / µm
0.201
0.199
0.199
0.199
0.201
0.200
0.001
Ni / µm
7.60
7.58
7.58
7.59
7.61
7.59
0.01
Cu / µm
14.53
14.48
14.52
14.48
14.55
14.51
0.03
Table 1: Results of 5 individual coating thickness measurements of 5-seconds
each for Cr, Ni and Cu on a chrome-plated trim strip.
1
2
3
4
5
X.
S
d / µm
7.44
7.45
7.43
7.46
7.47
7.45
0.01
Ni / %
11.58
11.62
11.59
11.58
11.61
11.60
0.02
Figure 1: Use of the mobile XAN 500 on chrome-plated rotogravure cylinders.
Table 2: Thickness and Ni content of a ZnNi/Fe layer, 5 second measurement.
Device concept
The new FISCHERSCOPE® X-RAY XAN® 500 X-ray fluorescence
measuring system incorporates FISCHER’s many years of
experience with X-ray instruments. It is specifically designed to
meet user needs for coating thickness measurement and material
analysis in process control and quality control applications. The
XAN® 500 enables reliable and precise measurement of small parts
in a mobile benchtop unit, measurement of large and bulky parts
with a hand-held unit, and easy transport of the entire measuring
system.
The XAN® 500 works with a very small and lightweight X-ray tube,
which operates with a maximum voltage of 40 kV (optional
50 kV) and 4 W power level. The measuring spot on the specimen
is circular with a diameter of approximately 3 mm. An SDD semiconductor detector is used for optimal energy resolution and
very short measuring times. The main housing is made from a very
light but sturdy magnesium alloy. This results in a weight of 1.5 kg
for the hand-held unit (including battery) and approximately 8 kg
for the complete benchtop unit.
The mobile benchtop unit is designed to allow small objects to be
positioned easily and therefore measured reliably (see Figure 4).
From a radiation protection perspective, this ensures safe use of
Figure 2: The mobile
XAN 500. Its protective
cover functions simultaneously as instrument
housing for benchtop
use and carrying case.
FISCHERSCOPE®
The proven WinFTM® software is used for quantitative analysis,
giving the XAN® 500 the same basic functionality as all FISCHERSCOPE® X-ray devices. Coating systems, materials and alloy layers
can also be analysed easily with the WinFTM® software. The
algorithm is based on the fundamental parameter method to
obtain reliable measurement data without requiring calibration
standards. Extensive functions for statistical evaluation, documentation and exporting measurement data give users the right tools
for process control and quality assurance tasks.
Applications
The XAN® 500 can be used with a wide variety of corrosion protection coatings, decorative coatings and functional coatings
in various industrial sectors, including electronics, automotive,
aerospace, domestic appliances and many more. An example of
a typical application is a chrome-plated trim strip (Table 1), which
has a three-layer structure. Even with a measuring time of just
five seconds, very good results can be obtained for all three layers.
N o . 12
Another example is measuring
zinc nitride coatings. In this case
the nickel content of the coating
is also important, along with
the coating thickness. Table 2
shows the results with a typical
coating. Here again, the repeat
distribution is very good even
with a short measuring time.
With the new XAN® 500, many
coating thickness measurement
and material analysis tasks can
now be performed “on the go”
with customary FISCHER quality.
Dr Bernhard Nensel
Figure 3: Easy removal of the hand-
Figure 4: Once the hand-held device
held unit.
is placed into its case, the whole unit
functions as a self-contained measuring system. Shown here: even the
positioning and measurement of
small objects is straightforward.
«closer examination»
New HT2000 measurement head: nano-indentation
on a new time scale
The various curves can be attributed to different material
properties of the glass specimens; external influences are
negligible.
The measurements in the second example were taken on an
acrylic sheet. The measuring conditions (maximum force and force
exposure time) were varied in the test with increasing force, while
the test force of 5 mN was held constant for creep measurement
after the force was released (Figure 4). Clearly visible differences
can be attributed to different initial conditions. This long-term
measurement capability creates new options for characterising
coatings, in particular soft coatings and materials such as polymers
and paints.
With the new HT2000 measurement head in combination with
either the FISCHERSCOPE® HM2000 positioner or the FISCHERSCOPE® HM2000 S stand option, precision measurements can now
be made over a time frame that was previously impossible.
For temperature monitoring and documentation, the measurement head can be equipped with an external temperature sensor
to determine the temperature close to the indenter or on the
specimen.
Thanks to the excellent temperature stability of the HT2000 in an
air-conditioned environment, individual measurements extending
over several hours are now possible without any effect on the
results from longitudinal expansion of the device. The maximum
temperature changed in the vicinity of the indenter is 0.2°C over
a ten-hour period, with the applied force being varied between
several values from 5 to 2,000 mN at hourly intervals (Figure 2). For
the first time, this allows the creep characteristics of materials to
be investigated over extended periods without any influence
stemming from the instrument.
This can be illustrated by two examples. Figure 3 shows the creep
behaviour (plastic deformation of the material with constant force)
over a period of one hour for various types of glass. The measurements were taken with a Vickers indenter and a test force of
2,000 mN.
N o . 12
Figure 2: The temperature near the indenter (blue) stays nearly constant over
the 10 hours, although the force (green) is varied between 5 and 2000 mN
during that time.
FISCHERSCOPE®
Figure 3: At constant temperature, the different creep behaviours of different
Figure 4: The creep behaviour of acrylic at 5 mN (after release of force)
types of glass can be traced back to differences in material. Effects due to
is influenced decisively by the conditions of the preceding hardness
temperature-induced expansion are negligible.
measurement.
Another innovation is improved force and distance resolution.
High precision measurements are possible thanks to a noise floor
below 175 pm. Naturally, the new measurement head has a USB
port for communication with the computer. The status indicator
on the head shows the state of the instrument (switched on and
warmed up, for example) at a glance.
For more information, visit http://fischerscope.de/nano2b
Tanja Haas, MSc Physics Gottfried Bosch
«information from practice»
In situ XRD for routine production processes
X-
ra
y
Bragg equation
nλ=2dsinθ
n1
θ
d
A
B
X
n2
dsinθ
Figure 1: The diffraction of a monochromatic X-ray in the crystal lattice follows
from the conditions of the Bragg equation.
Measuring process parameters such as temperature, pH, gas
concentration or gas pressure at critical process points is now
standard practice. In situ monitoring of product characteristics by
process-level X-ray analysis is becoming increasingly common
in modern production monitoring because it eliminates the
time-consuming alternative of quality control in a test laboratory.
The Institute for Scientific Instruments (IfG) has more than a
decade of experience in process-level X-ray analysis. The use of
X-ray fluorescence (XRF) for production monitoring has become
established in recent years. We have shown in a process that
X-ray diffraction (XRD) is also suitable for quality control of
manufactured products.
Figure 2: The WO2 (011) peak is represented as a CCD camera image (upper half)
with a graph below it for quantitative analysis. The WO2 concentration can be
determined from a calibration curve. The top image shows a WO2 concentration
of 77.11% and the bottom image 2.17%.
FISCHERSCOPE®
N o . 12
In the XRF method, the fluorescent emissions of individual
elements excited by X-ray radiation are analysed. Each element
emits X-ray radiation at a specific energy level. This provides
information about the elementary composition of the specimen.
However, only limited conclusions can be drawn regarding the
presence of a particular chemical phase, and elements with low
atomic numbers are difficult to capture with XRF.
are fulfilled (Figure 1). Each structure generates a unique diffraction pattern, allowing individual crystal phases to be determined
and even enabling a clear distinction between compounds with
the same elements but different crystal structures. For example,
the gypsum (CaSO4* 2 H2O) and gypsum anhydride (CaSO4*
0.5 H2O) phases can be distinguished by their diffraction patterns,
as can a pure metal and its oxide.
If the product has crystalline bonds, phase determination is
possible with X-ray diffractometry (XRD). In this method the interaction between monochromatic X-ray radiation and the individual
crystals of a substance causes diffraction of the radiation from the
ordered crystal lattice when the conditions for Bragg diffraction
IfG and H.C. Starck jointly developed an in situ XRD analysis technique for production monitoring of a thermal reduction process
in which tungsten oxide is reduced to metallic tungsten powder
in the presence of hydrogen. The product contains unwanted
tungsten dioxide (WO2) if the reduction is not complete. For measurement, specimens are taken automatically from the product
stream at short intervals and fed into a measurement chamber.
The unwanted WO2 phase is then determined quantitatively using
XRD. After measurement, the powder sample is returned to the
product stream and a new specimen can be taken for analysis. XRD
measurement is performed with the X-ray tube and the detector
positioned at fixed angles to the specimen. The detected image
from a CCD camera is converted into a peak intensity, which is a
measure of the concentration in mass percentage (Figure 2). A
smaller angle range corresponding to the (011) peak of WO2
is used for analysis. WO2 concentrations as low as 0.2% can be
detected in the tungsten powder production process.
CC D
cam
e
ra
Sa
m
pl
e
t
re
rie
ve
r
Protec tive
housing with
X-ray tube
In situ measurements impose high demands on the integration of
the analysis system into the process (Figure 3). The entire system is
installed in an environment exposed to high temperature, high
dust burden and vibration from the production process. Aggressive gases may adhere to the specimens. With the in situ XRD
measuring system installed at H.C. Starck, we have shown that
these hurdles can be overcome and sustained process analysis in
continuous operation is possible.
Antje Schmalstieg, MSc Physics Renat Gubzhokov
IfG Institute for Scientific Instruments
Figure 3: In situ XRD system in use on a rotary kiln consists of an X-ray tube (right),
a sample chamber (centre) and a CCD camera (left).
© Copyright H.C. Starck GmbH
«information from practice»
New developments for correct thickness
measurements on microscopic structures
Figure 1: Example of small structures on wafers. Solder bumps about 30 μm thick
and 30 μm in diameter consist of a base of Cu with a 10 - 15 μm thick pad of SnAg
on top. The image was generated using confocal microscopy.
N o . 12
In the semiconductor industry and electronic components in
general, the structures to be tested get smaller and smaller. The
FISCHER XDV®-μ instruments give our customers the right tools
to correctly measure the thickness of gold, nickel, tin, tin/silver,
copper and other metallic layers on wafer pads, solder bumps or
SMDs with a diameter of 30 μm.
Reliable measurements on these small structures are only possible
when several conditions are met. First, instrument device structure
and table precision must be suitable to ensure a positioning
accuracy of less than 1 micrometre. Second, only specifically
suited X-ray optics that effectively focus all of the beam on the
measurement area can be used. Third, suitably optimised software for adjustment and evaluation is required.
FISCHERSCOPE®
Halo effect
Figure 2a: Example of a
Figure 4a: SEM image of a
scan with Sn-K over the
wafer with Sn pads 40 μm
edge of a foil. The curve of
thick. The thickness of the
the measurement points
Sn layer on each pad was
indicates a significant
measured with capillary
halo effect.
types A and C.
(capillary A)
Figure 2b: Example of a
scan with Sn-K over the
edge of a foil. The curve of
the measurement points
no halo effect.
(capillary C)
The following discussion mainly addresses the properties and
characterisation of the X-ray optics. Polycapillary lenses composed
of several hundred thousand glass capillaries of micrometre dimensions are shaped with a specific geometry according to the
tasks they must perform. X-rays from the tube are guided through
the glass capillaries by total internal reflection and focused on the
specimen. However, X-ray reflection depends on the energy of the
X-ray quanta and the reflective material. The shorter the wavelength of the radiation, the smaller the total reflection angle. At an
energy of 20 keV, the angle is approximately 0.1° with normal window glass. To obtain proper focusing of the X-rays, the bottom
ends of the glass capillaries must be aimed as accurately as possible at the same small point. This requires bending them with the
right radius. Under these conditions, X-rays with energy greater
than 20 keV can strike the sample “unfocused”. This unwanted side
effect, which is called a “halo”, previously prevented the reliable
analysis of microscopic structures with spectral energy levels
The proportions of the focused and unfocused X-ray radiation can
be determined by integrating the calculated and measured intensities. In the chart in Figure 3 it can be seen that with capillary C
over 98% of the intensity lies within 50 μm on the specimen, compared to less than 80% with capillary A. A significant fraction of the
radiation from capillary A falls in areas that are several hundred
micrometres outside the actual focus spot.
The effect of this can be illustrated using a typical example from
the semiconductor industry. On a wafer there are pads of several
sizes (50 μm, 75 μm and 100 μm) coated with tin (Figure 4a). The tin
layers on the various pad sizes are measured using both sorts of
polycapillary optics. It is clear that when the capillaries with halo
Measured thickness of Sn on pads
(with/without halo)
1.0
Relative thickness
of Sn layer (µm)
indicates X-ray optics with
0.9
0.8
0.7
Relative thickness
of Sn layer
0
25
50
75
100
Pad measurement (µm)
Figure 4b: Comparison of the results of measuring Sn thickness on pads of
Figure 3: Intensity distribu-
different sizes with the two capillary types. Using the polycapillary (with halo)
tions calculated from
one obtains a smaller result for the thickness (normalised to the value of the
the foil scans for the two
halo-free capillary). On smaller pads the loss is even greater.
capillary types in Figures
2a and 2b. For capillary A,
about 80% of the intensity
is within 50 μm; the
remainder is spread out
are used, the measured coating thickness is approximately 20%
less because roughly 20% of the radiation lands outside the pads
on the specimen. The smaller the pad, the stronger the effect, as
can be seen from Figure 4b.
over a large halo. For
capillary C, approximately
98% of the intensity is
within 50 μm.
above 20 keV, such as the Sn-K line at 25 keV. IfG in Berlin has now
succeeded in producing halo-free capillaries. Their properties and
potential uses are briefly described below.
With this innovation, IfG and FISCHER have together managed
to develop the first polycapillary optics optimally suited to the
analysis of microscopic structures. It will be used as standard in
FISCHER’s XDV®-μ devices for wafer analysis.
Marcel Bermekamp, MSc Physics
Dr Wolfgang Klöck
Polycapillary optics can be characterised by an intensity scan over
the edge of a metal foil, in this case tin (Sn-K line). The steeper the
intensity distribution, the better the focusing of the polycapillary
optics. The two figures below illustrate the difference between
polycapillary optics with and without halo.
FISCHERSCOPE®
N o . 12
«closer examination»
New SIGMASCOPE® SMP350 conductivity meter
Checking for mix-ups from automotive suppliers
Vehicle parts must be tested for crash strength. Unfavourable
changes to the material properties occur when the heat treatment
has been incorrectly applied. Aluminium alloys with various hardness grades resulting from different heat treatments are tested,
since only artificially aged profiles may be used for further processing. Vehicle manufacturers need a test for this to ensure that no
mix-ups have occurred.
Figure 1: The new SIGMASCOPE® SMP350 with high-resolution touchscreen
Figure 2: A technician uses the SIGMASCOPE® SMP350 to check material
display interface.
properties on an airplane.
The electrical conductivity of non-magnetic metals is an important
material property that provides information about how well a
metal conducts electricity as well as indirect information about
its composition, microstructure or mechanical properties. The
SIGMASCOPE® SMP350 measures specific electric conductivity
using the phase-sensitive eddy current method as described in
EN 2004-1 and ASTM E 1004. The signal processing technique
enable contactless measurement of conductivity even under a
paint or plastic coating up to 700 μm thick. This instrument
is used in numerous applications.
Probes
All probe types with multiple frequencies in the range of 15 kHz to
2 MHz are suitable for use in these applications. All probes can be
connected to the same type of device.
Aircraft industry
Testing is carried out to determine whether aluminium alloys have
been overheated during milling. Before a part is released for series
production, the conductivity of a preproduction part is fully
tested. This assesses the requirements for the material properties.
Because material properties can change while the aircraft is in
service, cells are checked periodically.
1
2
3
4
…
10
Average
Standard deviation
N o . 12
σ (MS/m)
22.46
22.53
22.56
22.54
…
22.46
22.52
0.04
Table 1: Measurements of aircraft-grade aluminium with the
SIGMASCOPE® SMP350 and the
FS40 probe. The electrical
The FS40 probes are proven for the aircraft industry. Among other
things, they can be used to test for heat damage and material fatigue.
The newly developed FS40HF probe is a high-frequency probe for
near-surface measurements. It is particularly suitable for testing
thin sheet metal and layers, as well as thermally sprayed coatings.
The new FS40LF is a low-frequency probe suitable for measurements on thick sheet metal as well as for material testing in coin
production.
A thermal sensor – either the integrated or optionally available
external one – makes it possible to measure ambient or sample
temperature. The temperature effect on conductivity is compensated automatically to avoid incorrect measurements.
Standards for calibrating the instrument are necessary because
comparative measurements are performed with the eddy current
method. Certified standards are available for the entire conductivity range. For the aircraft industry, FISCHER is the exclusive
supplier of conductivity standards traceable to Boeing.
conductivity of aircraft aluminium
is typically 19 – 24 MS/m.
Dr Sebastian Zaum
FISCHERSCOPE®
«information from practice»
Quality service – the key to long-term
customer satisfaction
FISCHER instruments are known for their outstanding precision
and long life. Two factors are crucial for this: instruments of the
highest quality and outstanding service. Therefore, excellent
service is an essential factor for determining whether or not an instrument can deliver full performance over its entire service life.
High-quality service can only be guaranteed by a highly-trained
service team. At FISCHER, our worldwide presence and broad
product portfolio make especially high demands on the service
organisation. That is why we give high priority to the regular sharing of knowledge within the service organisation. Our service
training courses provide the right tools to achieve this goal.
There are more than 90 dedicated service technicians worldwide
ready to assist our customers. The service training programme
keeps our employees trained and up-to-date at all times, therefore
ensuring outstanding expertise in the global service team.
This enables FISCHER to offer expert service and numerous
service products locally in all sales regions; these include:
• Service and maintenance agreements with yearly upkeep
• Preventive maintenance
• Repairs
• Calibration
Due to their high precision, FISCHER instruments are often used to
test critical quantities. It is therefore crucial that our instruments
are ready for use again as quickly as possible should a repair be
needed. For this reason, we keep on stock in our worldwide
branches key spare parts that are essential for operation, so they
can be delivered promptly.
The benefits of our service organisation are obvious: worldwide
service expertise and trusted support, quick response times due
to local presence, support in local languages and familiarity with
local circumstances.
That is because our sole objective is to create clear added
value for our customers through outstanding service quality.
www.helmut-fischer.com
FISCHERSCOPE®
N o . 12