Posts Tagged J-STD-075
Thermal Profiling and Vapor Phase Soldering
Posted by Paul Austen in Vapor Phase Soldering on September 9th, 2010
There has been some new talk by some of the best quality conscious electronic manufactures about the many benefits of an older soldering process: vapor phase soldering. Vapor phase soldering has a lot of good things to offer, now that we have gotten past the stigma of the old CFC fluids and moved on to newer chemistries. The maximum temperature that the assembly can be subjected to is dictated by the boiling point of the fluid being vaporized. Because the boiling point of the fluid is a physical constant, you might think, “Why bother running a thermal profile on the assembly being soldered.”
This idea should be considered carefully, and here are some reasons why thermal profiling in vapor phase soldering is still a very good idea:
1. Although the boiling point of the vapor phase fluids is a physical attribute that limits the maximum temperature, the condensation of the fluid onto the components can impart a lot of heat, real fast. This can subject components to the old thermal shock problem, and unless this heating rate is carefully controlled by the vapor phase machine, you may well be shocking the components. Thermal profiling is the only way to show this is under control.
2. The maximum temperature is a function of the fluid type, and one needs to be sure the correct fluid is being use. There is a fluid whose boiling point is hot enough for lead free soldering, and not too hot for leaded soldering, about 230ºC. This “happy medium” is a good compromise, so one does not have to own two different vapor phase machines, or change fluids from one process to the other, but it is another reason why thermal profiling is a good idea: to prove that the process is meeting the need of the solder paste and the limits of the components.
3. A process undocumented is a process out of control. Unless you have some evidence that the thermal profile is meeting the requirement of the solder paste and the limits of the components, you cannot prove the process is in control statistically. You can’t make process control charts if you don’t measure the process. This is at the heart of a good Thermal Quality Management (ThQM) program.
4. Your customer still wants to know what the thermal profile looks like. No matter how you solder your customer’s boards, they still want to know what they were subjected to, thermally. This is your assurance to them that you have treated their product properly.
MOLE Talk
Posted by Paul Austen in Thermal Musings on June 28th, 2010
Yes I know, I’m ripping off the Car Talk radio program name, the truly funny call-n show where two well educated brothers have the best of fun giving advise (correct for the most part) to their call-in victims about everything from car repairs to personal relationships. If you’ve not heard the program, find your local NPR radio station and check it out. And also, I’m following on the heels of Board Talk, a web based collection of questions and answers by two respected members of the electronic assembly community who do a nice job (in a “Car Talk” like format) of answering many common questions submitted by followers of the Circuitmart web based electronic assembly resource.
So why take the risk of being yet another abuser of the “Car Talk” theme? Well because I have been asked this question many times: “Why did you call it a Mole?” Call what a Mole?
You know the M.O.L.E. ® Thermal Profiler, that pocket sized 6-channel temperature measurement logger used to see if you are getting the right temperature to your solder joints without overheating your thermally sensitive components (J-STD-075) in reflow or wave soldering machines.
There is a mouth full! Well, to answer this question I thought I’d take a look at the many really cool things a Mole can be. Here are a few:
A Mole of any substance shall have the same number of atoms, molecules, ions, or other elementary units, as the number of atoms in 12 grams of carbon. That number is: 6.0225 × 10^23, AKA: Avogadro’s number. So if you want to calibrate your scale, simply pile up 602,250,000,000,000,000,000,000 atoms of carbon and you’ll have 12.001 grams.
An annual celebration of the date and time represented by the numbers 6.02×10^23 or October 23 from 6:02 a.m. to 6:02 p.m. There is a cool web site in honor of this important number in the world of chemistry and physics. Check it out.
A small gray burrowing mammal, that is for the most part blind, although they probably can tell night from day. Moles tunnel through dirt and eat small worms living mostly underground. Moles can be found in most parts of North America, Asia, and Europe, although there are no moles in Ireland.
What do you call a Mole’s baby? Yes, a Pup. A female Mole is called a sow and the male is called a boar. And if you have more than one Mole you have a “company” of Moles.
A benign skin tumor found on human skin appearing as a small, sometimes raised area, with darker pigment.
A Mexican sauce made from chili peppers, other spices, and chocolate. However, it’s pronounced “Mole-Ay” and I often take service calls from Spanish speaking customers who say they have a “Mole-ay” that is due for calibration. I recommend this dish at your favorite Mexican restaurant. However, there are many different ways to make it so if you don’t like it at one restaurant, don’t be afraid to try it again at another.
A spy who has worked their way into an organization or country for the purpose of getting information. Wasn’t there a TV show?
A pier, jetty, or junction between places separated by water. I did not know this could be called a Mole until today.
A complete line of stage and production lighting products made by the Mole-Richardson Co I’m into theatrical lighting so naturally I’d know about this one.
OK, so this has been fun. Can we get on and just answer the question, “Why did you call it a MOLE?” Taking from the best parts of the many uses of the word Mole, we grabbed the following:
- A Mole crawls through tunnels.
- A Mole secretly spies on the goings-on of something or someone without detection
- A Mole of something is a number that starts with the number 6 (6.02…)
- A Mole is a delicious Mexican sauce. OK, we took nothing from this possible definition of Mole.
Put these together and you get an instrument that goes through the dark tunnels of many different thermal processes, measures the temperature of that process without disturbing it, and does it in 6 (or 3, or 20, since the original naming of the brand) locations of that process. Only a M.O.L.E. ® can do that. So that is why we called it a Mole. So what does the acronym M.O.L.E. stand for?
M = Multichannel – more than one temperature measurement input
O = Occurrent – events that happen (or occur) at the same time
L = Logger – a recording instrument
E = Evaluator – one who makes a judgment, as in the “OK” button on the new V-M.O.L.E. and MEGAM.O.L.E.
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.
Thermally Sensitive Components and J-STD-075
Posted by Rex Breunsbach in Profiling, Reflow Profiling on March 26th, 2009
Good solder joints are not enough. A good reflow profile must consider component temperature limitations.
The new IPC standard released Dec 08, Classification of Non-IC Electronic Components for Assembly Processes, J-STD-075, calls for thermal classification of components, and recommends a marking system to help contract manufactures recognize component temperature limits during the soldering process. Failures don’t show up during initial test, but much later on in the product’s life – often six months to two years later, and well below forecasts that drive pricing and warranty policies. ALL parts have temperature limits; and until we take the time to profile the process to which we subject these parts, we can’t know if we cause harm or not.
ECD has moved in that direction with our Thermal Quality Management (ThQM™) Program. We think this will give the industry the knowledge and tools to look at ALL components in the comprehensive light necessary. Equally important, it introduces a program and method of dialog between OEM and EMS provider on soldering process issues.
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