Technical Profiling Tips
- SAVING CLASSIC PROFILES IN SuperM.O.L.E.(R)
GOLD SPC SOFTWARE 8/7/01
- Exporting Data 9/13/01
- FAQ on ECD's Profile Planner Software Tool 11/5/01
- Exporting Data # 2
- Consider Oven Loading When Planning Your Board Thermal
Profiles
- Attaching Thermocouples 06/04/02
- Thermocouple Verification 07 30 02
- Place Thermocouples in at least 2 locations
08/20/02
SAVING CLASSIC PROFILES IN SuperM.O.L.E.(R)
GOLD SPC SOFTWARE
In brief, let the software do it for you! That's right, each new download is
automatically saved to a new top row of the Spreadsheet, whether you're doing
work in SuperM.O.L.E. Gold SPC, OvenRIDER(r)
SPC or WaveRIDER(r) SPC 4.03
software or above.
This AutoM.O.L.E. Software Suite, currently distributed with new product on
CD, implements our common program interface. In the interest of simplicity,
this tech tip will focus on SuperM.O.L.E. Gold SPC.
To our many customers who have been with us from the first SuperM.O.L.E. Windows
software to even the DOS days, it is important to get out of the habit of using
the SAVE-AS command to save a profile. And, those of you with an inclination
to use the SAVE-AS command, please understand what this really does.
Beginning with SuperM.O.L.E. for Windows version 3.x and continuing with the
4.x versions [currently 4.03a] that added statistical process control (SPC)
functionality, the program is organized in a Workbook/database style. A row
of tabs appear in the lower left-hand corner of the screen for navigating around
the program. Downloaded data still creates ".MDM" files, and Workbook
files have an extension unique to the product.
SMFW 3.19 = .MSM
SMG SPC = .MPC
WR SPC = .MWR
OR SPC = .MOR
The .MDM contains the data downloaded from the M.O.L.E. and the Workbook contains
everything else - the structure of the database, it's text [including USER Notes],
SPC limits and programmed Summary Stat values, etc.
The FINDER of 3.19 and SPREADSHEET of 4.03 are the window to a given WORKBOOK's
contents. Each new download is automatically assigned a sequential FILE TAG
number that is also the name of the .MDM data file. A selected row in the Spreadsheet
corresponds to the profile that's available for viewing from the PROFILE tab
view. In 4.03, the Spreadsheet displays the "=/=" character in the
row number column when that .MDM data is NOT available [so the profile won't
be either].
The key is that the commands NEW, OPEN, and SAVE-AS from the FILE menu of the
Spreadsheet or Profile tab views operate at the Workbook level and NOT at the
download file level. New Workbooks may be created for different production lines
or customers, etc. when the complexity outstrips the Spreadsheet Filtering functionality.
The NEW command is used to create a new and separate Workbook that can be navigated
to by using the OPEN command prior to downloading data. It will be empty of
data rows until files are either downloaded or imported into it. SAVE-AS functions
as a shortcut to creating a new Workbook for a just downloaded profile run to
reside in.
Once your workbook is created using NEW or SAVE-AS, you will in the future
use the OPEN command prior to performing downloads corresponding to the criteria
of that given Workbook. If the SAVE-AS command is used each and every time,
you'll have a bunch of 'one-shot' Workbooks littering your drive. As long as
you've got a .MDM file though, you can use the IMPORT command to 'make it active'
in another Workbook.
Workbooks organization lies at the heart of data integrity for meaningful SPC
control charting and process capability studies. One set of Summary Stat Values
[Programmable Time Between and Time Above in 4.03] and one set of Lower and
Upper Specification Limits [and Control Limits if you so choose] avoids an 'apples
& oranges' approach to data collection. We encourage our customers to fully
utilize the green USER columns in a consistent way as well [Spreadsheet columns
A-E]. Dedicating certain columns to the entries of part number, production line,
customer name, operator, etc. not only provides easy implementation of Spreadsheet
Filtering, but all this text appears in the Tool Status Box of the Profile tab
view for further identification.
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Exporting Data:
ECD's SuperM.O.L.E.® Gold SPC 4.03 software is a full featured profile
analysis program from which product communication, profile development, profile
data basing and statistical process control are conducted under one roof.
On those occasions where critical profile data must be shared cross-platform
to existing corporate reporting formats and third-party SPC programs, the requirement
for SuperM.O.L.E. data exporting exists
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The method for extracting this data is to use the "List-Print Data"
command. From the Profile view, you'll find this command from the File
menu.
Selecting the File button creates a .PRN text file containing the above
information for the duration of the profile run that Excel import wizard
or a CAD or SPC program can easily open.
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Tips:
1] Set a path of your choosing for the .PRN file to be saved to so you can easily
find it [such as the Desktop].
2] Set the X-Axis to your desired units beforehand so that the first column
is truly a timestamp [Units command from the Profile menu].
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FAQ on ECD's Profile Planner
Learn More about our FREE Profile Planner:
http://www.ecd.com/products/profileplanner/
Q. What is the Profile Planner?
A. The ECD Profile Planner is an Excel Workbook that includes a database of
many of the Solder Pastes that are available for reflow soldering along with
their recommendations for Ramp, Soak, and Spike specifications. Using these
specifications and the selected oven, the Planner includes a Robust Profile
Calculator that shows you the "most robust profile" that can be generated
in that oven, with that paste. The "most robust profile" is the profile
that is closest to the "ideal profile" as presented by the paste manufacturer.
The planner, using Bob Rook's algorithm, allows you to see in which zones the
paste specification boundaries exist. The user is allowed to change the paste
specifications in the Planner and see the resulting profile that will be generated.
Q. Why use it?
A. If you want help in deciding which paste to use in an oven or want guidance
on what profile you want to achieve, the Planner will help you with this process.
Employees new to soldering profile development are barraged with masses of data
and opinions and often ask; "Where do I Start?" The Planner provides
this starting point in a concise and easy-to-use manner. Now you have a tool,
at no cost, which shows product exit temperatures at each heated zone boundary.
Throughout the Ramp, Soak and Spike regimes, the Profile Planner shows you the
optimum profile for that combination of paste and oven.
Q. How to use it?
A. 1) When you choose a Solder Paste and Oven combination, and the conveyor
speed is appropriate for your manufacturing reality, simply press the Print
Chart button located on the graph of the Robust Profile Calculator worksheet.
This Robust Profile shall be visually compared to an instrumented circuit board
assembly profile.
2) Now, bring up the SuperM.O.L.E.® Gold SPC [or competitive] program.
Select and print a previously generated original profile from an assembly somewhat
similar to your current project.
3) Compare those non-optimized results with the printed Robust Profile generated
by the Planner.
4) Then perform Dynamic Prediction to adjust oven set points to gain agreement
with the Robust Profile which represents ideal values for this combination of
paste and oven, while observing the requirements of the components the assembly
is populated with.
5) Profile your current assembly first-off and analyze the results. ECD's Xpert
Systems automate this entire process without the need for a baseline profile.
Meanwhile you see that you can take advantage of this process development tool
with any profiler make and model. See http://www.ecd.com/xpert for more information
Q. What is the Goodness Value?
A. Goodness is a relative number that attempts to quantify the 'fit' that exists
between the ideal and the robust profile. Since a temperature set point cannot
be changed mid-zone, one can observe that the more zones an oven has, the better
the chance of zone boundaries [Robust Profile] matching the Ramp to Soak and
Soak to Spike transitions of the paste specification [Ideal Profile]. The error
this is measuring may not have a significant bearing on how a part might solder.
A higher number does indicate that you are able to achieve a profile closer
to the ideal profile and recommended by the paste manufacturer.
Q. This is a great tool. However, I would like it to give the recommended settings
for the oven that I am using. Will this be in a future release?
A. It is not likely. This feature is built into AutoM.O.L.E. ® Xpert. (
http://www.ecd.com/xpert ) In developing the Xpert systems, we run a battery
of tests on each oven to determine its response to setting changes and relate
this information back to specific profiles. This data is then used in our automatic
setup process of the oven. In the Xpert - once you select the paste and board
information, it will set up the machine to achieve that profile. You can then
check the profile to be sure this occurred and adjust again if needed. Most
customers find that the initial setting is right on the money.
Q. Why are there so many parameters for each paste?
A. Each paste has a range of values for each part of the paste spec. We use
the upper and lower values to calculate a reference NOM value, which is typically
the average of the 2 values. The Planner uses the NOM value to do all of its
calculations, which is initially set to the Reference Nom Value. As a user,
you can change this Nom Value on the Paste Specifications page. You can also
change it for just this profile on the Robust Profile Calculator page (Nominal
User Set). If you change paste or oven, you need to clear this value.
Q. Why is the speed of the conveyor so fast (or slow)?
A. In order to achieve the average of Nom paste specifications as described
by that manufacture in the oven that you selected - that is the speed that the
conveyor would run. This does not mean that the oven can achieve these settings
at this speed. Use the Planner to set the speed that you run now and see the
effect on the profile. You can also change other parameters to see what flexibility
you might have.
Q. There are blank cells at the end of the Paste Specifications - can I use
this space?
A. Yes you can. There is a wizard built into the Planner that helps you add
pastes and ovens, however you can add one or two directly in the blank cells.
It will not allow you to enter the reference nom values. You can also modify
the values of any other paste.
Q. Will you add more ovens?
A. As more ovens become Xpert ready, they are added to the database. It is easy
for the user to add an oven or change the values of an existing oven.
Q. Will you account for assembly configurations?
A. No. The parts on a circuit assembly determine the oven zone settings required
to achieve proper reflow without undue thermal stress. This is a job for AutoM.O.L.E.®Xpert.
Q. If I add a paste or oven, will I lose this information when I upgrade?
A. Unfortunately, yes. If you have a paste that is not in our database, please
send the information on the paste and the manufacture to profileplanner@ecd.com
and we will try and get it included in a future release.
If you would like to learn more about the Profile Planner, please visit:
http://www.ecd.com/products/profileplanner/
To download your copy (now at version 1.07b):
CLICK HERE!
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Exporting Data #2
We continue to get inquiries on how to export data from our software - this
tip continues this thread.
While ECD's SuperM.O.L.E. Gold Software for windows has a variety of built-in
charting and reporting options, many of you have expressed a desire to be able
to export your profiling data into other applications such as Microsoft Excel.
This is a very easy task....here's how to do it:
1. From the Profile tab, select the command List-Print Data from the File menu.
http://www.ecd.com/images/tech_tip_2.gif
2. Make sure the X-axis units are set to "relative time" - this will
"Time Stamp the data"
Use the Units command from the Profile Menu
3 You will see 6 columns of time-stamped raw data.
4. Press the Print to File button and a text file you name with the extension
'.PRN' will be saved to your choice of location.
5. You can now use the Excel import wizard to transfer this comma delimited
file into an Excel spreadsheet and utilize Excel's charting and data manipulation
functions
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Consider Oven Loading When Planning Your Board Thermal
Profiles
This tip from Solder Industry Expert -
Ray Chartrand of Chartrain
Consulting
People often go to great lengths to assure their electronic assembly sees the
proper amount of heat for the correct time. This is often performed at the pilot
run or prototype stage. During these trials the assembly is generally run alone.
This is not a realistic production situation. If normal throughput sees boards
spaced one assembly apart, and the golden board is run alone, there may be a
significant change in profile.
Not all ovens are created equal and some react better to loading than others.
During a failure analysis I performed some years ago, the assembly met reflow
conditions when run alone yet dropped to 20 degrees below liquidous during production.
The oven software and heater controls were unable to detect variations on oven
loading.
Next time you assess a prototype assembly, load the oven and insert the thermocoupled
assembly in the middle of the run with assemblies before and after it. Better
safe than sorry.
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Thermocouple Attachment: A Technical Tip From
Industry Expert Ray Chartrand
How to attach a thermocouple is a subject that is often debated. Glue, tape,
foil solder, even paper clips have all been used but are they accurate and repeatable?
To answer that question, a number of years ago, I attached 6 thermocouples
to a bare copper coupon in a grid pattern. Thermocouples were attached using
63/37 solder (which was silly), Kapton tape, crazy glue, conductive epoxy, high
temp solder and a TempProbe (tm). The oven was allowed to stabilize for 30 minutes.
20 passes were made through the oven with the coupon cooled to room temp between
each run. The high temp 95/5 solder and TempProbe (tm) were the only two methods
that remained intact and repeatable for the duration of the test.
You should always verify the thermocouple attachments before profiling your
"Golden Board." The repeated use of this assembly can result in thermocouple
attachment degradation and failure. This is hardly what you need to insure process
repeatability.
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Thermocouple Verification - A Technical Tip from Ray
Chartrand
Thermocouples can degrade or become damaged through use. Before running a test
assembly or golden board or when reattaching used thermocouples it pays to insure
their function before attachment.
One simple method is to plug the thermocouples into the data recorder and allow
it to record for a few minutes. Download the data and verify to see that all
channels read the same, i.e.: room temperature.
Another way to verify function is to turn the data recorder on and immerse
the thermocouples [tightened into a bundle] into a glass of ice water. Ice remains
at one temperature 0 deg C or 32 deg F which is the value you should see when
the data is downloaded.
PS don't drink the water afterwards!
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Place Thermocouples in at least 2 Locations
From 3 channel temperature profiling units to some having almost two dozen
inputs, a lot of data can be obtained. Where to start with the attachments?
At the very least we want to see are the hottest and coldest spots on any assembly.
The hottest spot will be the PCB laminate and the coldest spot will be the largest
component or a ground plane. The goal is always to heat the largest mass to
sufficient temperature without overheating the smallest. The temperature differential
between these two is commonly referred to as the Delta T.
In addition, any heat sensitive components such as ceramic capacitors should
also be profiled.
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