ACT - Accuracy Check Tool.pdf - 第181页
ACT with SSW 7xx / User Manual 07/2017 Edition 73 NOTICE When measuring the ceramic compo nents, the plac ement angle c annot be calculat ed, as the ceramic compon ents are too small to deliver reli able informatio n for…
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4.2.7.1 Measurement Evaluation and Measurement Data
The measurement results are then displayed as follows:
Figure 4-50: ACT measurement results
Key:
(1) Median value, can be changed with the Automatic offset correction…
button.
(2) Standard deviation at 4 sigma.
(3) Cmk: must be 4 Sigma >1.33 and 3 Sigma > 1.0.
(4) Here you can switch between the heads (gantries).
(5) Measurement details.
(6) Switches the measurement result.
(7) Here you can correct the measured offset values.
(8) If the head in use is a Twin Head, you can select the individual
segments here, if both segments have placed components on a plate.
As of software 709.xx, the result of the individual segments of a head
can also be displayed here.
X
Displays the offset values in the X direction.
Y
Displays the offset values in the Y direction.
Angle (not for Cerampads)
Displays the offset values for the placement angle.
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NOTICE
When measuring the ceramic components, the placement angle cannot be calculated, as
the ceramic components are too small to deliver reliable information for the angle.
Therefore the angle is not displayed.
For the CA-series and X-series S micron machines with C&P20 M placement heads and
the corresponding programs with "High Precision" flag, the expected measurement
accuracy is so high that the errors occurred due to the component size are irrelevant for
the result.
The measured values are highlighted in color. This allows you to see, for instance, whether
components which were positioned with a particular placement angle and by a particular segment
show particularly significant deviations.
The PDF evaluation (see section 4.2.7.3) outputs data on segments and overall values for the Twin
Head.
NOTICE
In rare cases (pickup errors and thereafter recovery placement), individual segment
assignments might not be correct. If it is necessary to know the segment assignments
when analyzing the measurement results, the placement has to be repeated until the
segment assignments are correct.
The results displayed in the Statistics area and the graphical view of the measurement results
match the selected head and the selected segment.
Mean (calculated average, offset)
The average calculated here relates to the results activated in the head selection (and for Twin
Head, segment selection). This is the calculated average, i.e. the sum of all measured values /
number of values.
Median (central value)
The median relates to the results activated in the head selection, too (and for Twin Head, segment
selection). This is the "middle one" of the measuring values. To determine the median, all
measuring values are arranged according to size. The measuring value in the middle of the list of
all measuring values then shows the median (by 5 measuring values this is the 3rd value).If there is
an even number of measurement values, the median is defined to be the arithmetic mean of the
two middle values (by 4 measuring values (x2 + x3) / 2). The median is inured to so-called runaway
values, because these will be sorted at the beginning or the end of the list of measuring values.
Standard deviation
The standard deviation is displayed as 4
σ
or as 3
σ
(for CA, micron, E by SIPLACE).
Automatic Offset Correction…
The offset data can be automatically corrected. A click on the appropriate button opens a dialog in
which the offset values to be corrected (median values) can be selected. See section 4.2.7.2.
Measured values
Displays the total number of measurements.
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Errors
Displays the number of measurement errors per measurement. The user decides whether the
number of errors is too high and whether to repeat the measurement process.
► Check the measuring plate before you repeat the measurement. Possibly the foil was not
applied to the plate without air bubbles or the surface is scratched or dirty if the plate has been
used several times.
Repeat measurement
Repeats the current measurement in the selected mode, another placement operation will not be
performed. Each measurement can only be stored once (Report created). If the measurement is
repeated it can be stored again (Create report).