Archive for category Thermal Profiling
MOLE® Thermal Profiler Calibration – Why and When?
Posted by Paul Austen in Thermal Musings, Thermal Profiler, Thermal Profiling on July 26th, 2010
MOLE® Thermal Profiler Calibration – Why and When?
Calibration of electronic measurement instruments is a necessary process, even though most electronic equipment is very stable and somewhat “resistant” to the effects of environment and changes due to aging.
Q: So why calibrate if my MOLE is “in spec” every time I send it in for calibration?
Because calibration is not so much an adjustment process but rather a proofing process that shows, over time, that your MOLE has been in calibration and thus should remain in calibration, because you have a track record to prove it. Documented history of a MOLE’s performance is the only way to claim your MOLE is in calibration at any given instant.
Most good labs will tell you that when your MOLE is calibrated, it is compared to standards , typically standards that have traceability to NIST, and if it is shown to be measuring within its specified accuracy they will not make any attempt to “adjust” it. Only if it is “on the edge,” which usually means it is getting to the last 10% to 20% of the specified accuracy limit, will they make any adjustments. Your MOLE may still be “in spec” and thus “in calibration,” when the lab received it, but getting close, so they will adjust it closer to the middle of the spec. range.
If it is out-of-spec when received by the lab, then a red flag goes up and calls into question every measurement made since the last calibration! The lab will tell you how far out of spec it is, and you can decide if its measurements during that time affect the quality of the measurements made more than can be tolerated, or if they are “close enough” to still be acceptable.
Q: So, when should the MOLE be calibrated?
The number one best time to calibrate the MOLE is on a regular time-based interval, which is recommended once a year. However, there are other events which may cause you to want to seek calibration at other times of the year, such as:
- When the MOLE is subjected to rough treatment like a fall to the floor,
- When your MOLE is accidently “over heated” ,
- When you are starting a new product introduction and you are characterizing an oven and new assembly to find the right recipe,
- When a new customer’s contract stipulates you use equipment that has been recently calibrated,
- When your in-house quality program requires a calibration interval.
Getting your MOLE calibrated is easy and we want to make sure you are always making the highest quality temperature measurements.
On Reflow Soldering
Posted by Paul Austen in Reflow Profiling, Thermal Profiling on May 3rd, 2010
You know, at ECD we have been in the thermal profiling business for over 25 years. Most of what we profile is the reflow soldering process. There are many others like wave soldering, baking, drying, curing, and a host of other industrial temperature process. Still, reflow soldering is the most popular use for a thermal profiler like the MOLE. And yet, most of what can be found on the subject of reflow soldering, at least on the web, focuses on specific portions of the reflow process and not on the entire process as a whole.
For example, component manufacturers would have you avoid certain limits in temperature or temperature change rate (slope) to avoid damaging their parts. And that’s ok, but that only tells you what to avoid, temperature wise. Most solder paste manufacturers would have you believe that their paste can take most any reflow thermal process so as not to be excluded from purchase. This too is understandable and in reality, most solder pastes are good and will solder your components to your circuit board. Many standards (like IPC standards) on the subject suggest what your product MUST withstand to be considered robust and not necessarily an ideal reflow process thermal profile. This makes sense, because there is no one reflow thermal profile that will solder every possible circuit board assembly, and standards must be general in their application. Then there are the public websites that are often peppered with bias toward a specific brand of profiler in their description of what’s important or how to view it.
Each year new talent enters the work force and training in the art of reflow soldering is limited or costly. Worse yet, some learning about the reflow process only occurs from failures caused by incorrect reflow process settings. And perhaps worst of all, many reflow solder machine are still running the same setting set generations ago because no one currently available has the skill to make them better. Just because many industry veterans understand the issues around reflow soldering and thermal profiling does not mean the new talent can hit the road running. And, since most every electronic assembly will pass through either reflow soldering, wave soldering, or sometimes both, I thought it important to take a look at the reflow solder process, dissect it and consider what’s important to measure and control. Click here for the more in-depth look.
Diverse Needs, Diverse Solutions – We’ve got an App for That!
Posted by Paul Austen in M.O.L.E. MAP, MegaRIDER, OvenCHECKER, OvenRIDER, Reflow Profiling, Thermal Profiling on March 29th, 2010
How many different MOLE profilers and Test Pallets does it take to monitor a reflow solder machine? It depends on who you are and why you are monitoring it? We just want to make sure there are as many tools as there are reasons for running a thermal profile. Here are a few good reasons:
1. “I’m from the Metrology lab and it’s time for the annual calibration of your reflow oven.” We’ve got an app for that. After you’ve finished with the oven’s calibration procedure, you can run the MegaRIDER-20 with a Process Test Pallet to see if the machine is uniform across the conveyor width and has the same heating capacity as it did the last calibration or maintenance.
2. “I’m the Manufacturing Engineer and our QC Department wants me to show that this oven is in control.” We’ve got an app for that. You probably need more information than the once a year Metrology profile can provide. So weekly you can an OvenRIDER and see that every zone in the oven is performing the same using X-Bar R charts to prove it.
3. “I’m on the New Product introduction team and I need a good recipe to solder a new board without killing the parts.” We’ve got an app for that. The Super M.O.L.E.® Gold thermal profiler will let you connect T/Cs to the board to see exactly what’s going on, thermally, on the areas where you and the designer have the most concern. Use the Prediction tools in the new MAP software to lock in the perfect recipe.
4. “I’m a Line Technician and I have to know my reflow oven is ready to run product without all the wires and circuit board stuff.” We’ve got an app for that. OvenCHECKER is one pallet loaded with the most powerful profiler on the market today. It takes no more time to run than the first production board and it lets you know if the reflow oven is ready or not. No downloading, no comparing numbers on a chart, just Go, or No-Go.
The Fastest Way to Know Your profile is “OK”
Posted by Paul Austen in Extracting Parameters, M.O.L.E. MAP, Reading Profiles, Reflow Profiling, Thermal Profiler, Thermal Profiling on February 25th, 2010
Now there is a way to verify that your profile requirements are being met in less time than you ever thought possible. The letters in the name M.O.L.E.® thermal profiler have always stood for Multi-channel Occurrent Logger Evaluator. Now the patented* “OK button” feature truly makes “E” in MOLE a reality, because now the MOLE profiler can automatically compare the measured temperature profile to your pre-programmed profile requirements.
The ECD V-MOLE with patented one button “OK” profile evaluation
(The OK Button is also available on the 20-channel MEGAM.O.L.E.™ thermal profiler, and OvenCHECKER™ )
Taking only seconds, the MOLE can tell you and your oven operators if the profile just measured is in or out of specification with the universally understood Green for good (GO!) or Red for bad (STOP!).
You get to set the specification limits for any or all of the four most popular profile parameters:
- Ramp Slope
- Time Between temperatures
- Time above Liquidous
- Peak Temperature
…and you can choose which of the MOLE’s input channels to include, up to 20 channels on the MEGAM.O.L.E.™, and three on the V-M.O.L.E.™ thermal profilers.
The Specification Table in MAP Software
Using the MAP™ Profiling software, enter your specification limits for the four profile parameters in the Upper and Lower Limits table in the “Target-10 OK” tab. These values will automatically be sent to the MOLE profiler when you use the Verify Process Wizard to confirm that a previously characterized oven recipe is still performing within specification.
MAP™ Profiling Software Target-10 OK Profile tab
Once programmed, the MOLE profiler can be used many times (up to 96 times) to Verify your oven is producing the same profile, without reconnecting to your computer. Simply run the profile and press the “OK Button” on the MOLE. No more running back to the PC software to download to see the results. One push of the OK button, and you get your answer…Go, or No-Go. It’s that simple!
*U.S. Patent Number 7653502.
Why do an Oven HealthCHECK™? Why Calibrate Instruments?
Posted by Paul Austen in Reflow Oven Verification, Reflow Profiling, Thermal Profiling on January 27th, 2010
Why do an Oven HealthCHECK™? Why Calibrate Instruments?
You might ask, why should I perform an Oven HealthCHECK? In other words, why should I run a rather sophisticated measurement system through my oven to produce a rather nice looking 3-D plot of the cross belt temperature uniformity?
Figure 1: An example 3-D plot of the oven with very good cross belt uniformity, < 3ºC
I may not like the answer because I might find out my oven has a problem that I cannot fix? Sounds like a “head in the sand” sort of excuse to me.
I would ask a different question: “Why do you calibrate your bench test instruments?” Is it to find out that the instrument is out of spec? Heavens no!! That would be a nightmare because it would call into question everything that instrument was used to test since the last time it was calibrated. So why do you calibrate if the results could be so disastrous? Simple, it allows you to show and document that the instrument is and always has been “within specification.” So when the auditor asks, how do know your instruments are in calibration, you pull out the Certificates of Calibration.
Figure: What’s the first thing you check after you receive your Certificates of Calibration? The “As Received: Within Tolerance”
ECD’s Oven HealthCHECK is designed to certify and document your oven’s performance or health. It is a “calibration” done on a regular interval, say once a year, to show that the oven performance is within specification and not changing over time. It can also provide a baseline level of performance around which you can compare into the future. Further, if you have several ovens, the HealthCHECK can show you which ovens are best for applications where oven uniformity is critical.
Back this up with much simpler and more frequent verification profiles of your oven using OvenRIDER or OvenCHECKER, where simple software-generated Xbar-R control charts show daily indications of a thermal process that is “in control,” and you will no longer have to steer the auditor around your reflow oven. You can proudly show that you know your oven’s performance level and that it is consistent because you have taken the steps to measure your oven’s health as part of your Thermal Quality Management program. Such a program should be marketed, since it shows you commitment to understanding your oven’s thermal nature and you have the data to show it. This sure beats the “head in the sand” quality program which may characterize your competition.
Profiling ovens and processes with multiple conveyor speeds
Posted by Rex Breunsbach in M.O.L.E. MAP, Profiling, Solar Cell Manufacturing, Thermal Profiling on September 29th, 2009
BTU Tritan Solar Cell Furnace
Ovens used in the metallization of solar cells can have 20 or more heating and cooling zones. These ovens can become quite long if the conveyor speed in the initial curing and final cooling sections are the same as the firing section. By speeding up the conveyor speed in the firing section the oven can be shortened and temperature of the cells can be increased and decreased more quickly.
Multiple conveyor speeds are also encountered in food processing lines where the food product passes through a several machines running at different speeds.
ECD’s newest profiling software can accommodate multiple conveyor speeds. Most profiling software assumes the
Solar Cell Metalization Time-Temperature Profile
conveyor speed in all zones is the same. ECD’s new M.O.L.E. MAP® software version 2.18a allows entry of a different conveyor speed for each zone.
Proper positioning of oven zones on profile time-temperature data requires accurate knowledge of the conveyor speed. By knowing the sampling interval, length of each zone and the conveyor speed one can calculate how many temperature samples “long” a particular zone occupies.�
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