Flux Remover C is MicroCare’s most popular cleaner because it is affordable, nonflammable, easy to use and safe to store. It features convenient handling, powerful cleaning, speedy drying and a very low aroma.
Suitable for all types of electronics, Flux Remover C can be used on through-hole, SMT and BGA boards, plus hybrids, cables and connectors. It is highly effective on no-clean fluxes, water-based fluxes, light oils, grease and inks. With a low surface tension and high density, this product gets under tight-fitting chips, flushing residues away. It can be used in heated cleaning systems.
Key Products Features & Benefits:
Prod. No. MCC-FRC101
Flux Remover C 300g Aerosol
Q - What is an Azeotrope and why is it important?
A - Many of the MicroCare cleaning products are azeotropes, and that’s important because it lowers your costs, boosts cleaning effectiveness and enhances worker safety. In general, these are all very good things.
So the next question is, how does an azeotrope do that? For that answer, we have to go back to Chemistry 101.
First, an azeotrope is best described as “a constant boiling blend.” To be an azeotrope, the material has to be a mixture or a blend of at least two different compounds. For example, neat HFC-43-10mee is an ingredient in some MicroCare solvents, such as Vertrel® XF. But it is not an azeotrope because there’s nothing else in it but molecules of HFC-43-10mee. In contrast, Vertrel® XP is a mixture of MFC-43-10mee and isopropyl alcohol. So Vertrel® XP could be an azeotrope (and is, as we will explain in a minute).
Now let’s consider the boiling point of these materials. The boiling point of HFC-43-10mee is about 50° C / 130° F. But if you mix HFC-43-10 with a small but precise amount of methanol the boiling temperature suddenly drops to 48° C / 118° F. This is very odd and unexpected. The two chemicals are still separate and distinct in the mixture, but when mixed together they jointly lower their combined boiling point.
When we boil this mixture in a beaker the two constituents will boil off at the same rate. Let’s supposed the mixture we are testing is 97% HFC and 3% alcohol. If we measured the fumes coming off the boiling liquid, we would be pleased to notice that the mixture of fumes also was at the same 97:3 mixture. When we chill those fumes and condense the material back into a liquid state, it will have the same 97:3 mixture. In fact, no matter what we do the mixture it always stays at the 97:3 proportions. This means we have created an azeotrope.
There is a bit of magic to making azeotropes. Not all liquids form azeotropes because the density, boiling point and surface tension all has to be exactly right.
Why Do I Care?
Azeotropes are cool. Azeotropic behavior allows engineers to deliver the benefits of a mixture with the convenient handling and storage of a single compound. There are three main benefits of azeotropes:
•Perhaps the most important benefit of an azeotrope is the unexpected ability to mix flammable and nonflammable ingredients to produce a stable nonflammable mixture. This is an amazing chemical phenomenon. Imagine mixing flammable products — like alcohol — into Vertrel® XF and yet still retain the convenient handling of a nonflammable chemical. But that is exactly what happens. In contrast, if a product is merely a mix of chemicals, when there is a spill of the solvent on the factory floor some flammable chemicals may evaporate faster than other chemicals, creating a cloud of flammable vapors above the spill. This is so important for safety that the process is simulated during the “Tag Closed Cup” flammability test. With azeotropes,the ingredients never separate.
•Another benefit of azeotropes is that they are very easy to distill and recover. If the solvent in a vapor degreaser is an azeotrope then the solvent can be boiled and recycled. Meanwhile, while the contamination — the non-azeotropic stuff mixed into the solvent, such as fluxes, oils, water, belly-button lint and such — stay “trapped” at the bottom of the machine. In effect, using azeotropic solvents allows us to trap and concentrate the contamination using distillation instead of using filters and membranes and such.
•Lastly, azeotropes permit the “tweaking” of a blend to obtain unique physical properties which makes the blends useful across a broad range of applications. For example, HFC-43-10mee is a very mild cleaner. But add some other ingredients in azeotropic proportions, and you can make a blend that is almost as strong as methylene chloride, or as safe as Freon®, or almost as cheap as HCFC-141b. In other words, azeotropes allow us to customize Vertrel® to fit almost any application or budget. The possibilities are almost limitless.
About Near-Azeotropes and Co-Solvents
Sadly, not all azeotropes are created equal. To a finicky chemist, a perfect “true” azeotrope only exists at a single temperature and specific pressure where the azeotropic behavior is observed. But “close” can be good enough. Many products are successfully marketed today which are not “perfect azeotropes” but near-azeotropes. These cleaners are so close to being azeotropes that they exhibit stable azeotropic behavior.
For example, many near-azeotropes can be repeatedly evaporated, condensed, and recycled without changing the blend’s composition or other properties. Even though it is technically just a mixture of different chemicals and does not meet the exact technical description of an azeotrope, a near-azeotropic solvent behaves as if it were a single pure component solvent rather than a solvent mixture.
One popular example of a near-azeotropes is the General Purpose Flux Remover from MicroCare. This cleaner is not a perfect azeotrope in the strictest definition of the word, but offers azeotrope-like stability and can deliver the performance, safety and time-saving convenience of single-solvent operations under almost all conditions. These products have been thoroughly tested, again and again. They are so close to being true azeotropes they can be used without problems in any application requiring azeotropic behavior, such as vapor degreasing.
Lastly, sometimes there is no single solvent or azeotrope which is sufficiently strong to get the job done. In this case, some customers switch to using a bi-solvent or a co-solvent system. These systems use two solvents — one aggressive cleaning solvent, and one milder rinsing solvent — to remove the most difficult soils. For more details about co-solvents, contact MicroCare.
Q - Do l need gloves when working with MicroCare solvents?
While casual and intermittent skin contact with most of the MicroCare solvents does not represent a significant health risk, wearing gloves is certainly is a good practice, especially if skin contact is likely and prolonged. This is particularly true when cleaning stencils by hand, using the presaturated wipes.
Common sense strongly recommends that prolonged or repetitive skin contact with any solvent or chemical should be avoided. After all, the MicroCare solvents are defluxers and degreasers. They are designed to remove oils and grease. This can result in the temporary drying, itching, swelling and roughening of the skin. This temporary irritation of sensitive skin is called temporary local dermatitis. Healing is rapid after the exposure ceases. But why work so hard? Wear gloves or finger cots and stop worrying about it.
Special note for individuals cleaning optics and optical devices: many optical systems are extremely sensitive to even the slightest contamination. That’s why the “dip-and-drag” method of cleaning is often used on optical systems, to avoid the slightest change of contamination or damage to fragile optical surfaces. MicroCare recommends our Optixx™ Precision Lens Cleaner for this application, and — more to the point of this FAQ — we also recommend nitrile finger cots when cleaning optics. The solvent is so good at dissolving oils that the solvent will actually go through a wipe, dissolve the finger oils on your hand, and then redeposit those oils on other side of the wipe — on the lens surface — before you can move your finger away. So finger cots are a major boost to productivity.
When selecting gloves, check the MSDS sheet to get the EXACT chemical name or CAS number for the solvent you are using; different solvents require different types of gloves. As a general rule for MicroCare products, Viton® gloves work adequately. In some applications a more durable two-part glove might be necessary. Chose the powderless option if it is important to control nonvolatile residues in your production process. These are widely available from quality distributors everywhere. Select the best impervious gloves and protective clothing you can find if there is any risk of skin contact. Gloves, splash goggles, aprons (when handling open drums) and safety shoes with steel toes are highly recommended.
In January 2008, Chem Info Magazine ran an excellent article with a voluminous information about Personal Protective Equipment, in particular gloves and glove selection when handling chemicals. The article provides general information about chemical compatibility, latex allergies, sizing, disposal and ESD control for gloves as well as splash aprons. All of these have relevance for many of our customers. A quick read may make you a bit more knowledgeable if asked by a customer what type of glove to use with Vertrel, Bromothane as well as MicroCare aerosol products. You can download the original article at www.chem.info.com