Author Archives: Keith Cathcart

  • Vision Engineering End of the Year Promotion

    OFFER 1

    FREE Smart Cam with every Lynx EVO system – a $1,910 value

    Take your inspection results to the next level with the Lynx EVO and get the Smart Calynx-evom HD digital camera and software for FREE!

    Smart CAM (EVC130) offers easy convenient image/video capture while retaining both optical paths for stereo viewing.

    • Stunning 3D (stereo) optical imaging.
    • Quickly and simply capture HD images or video.
    • Add annotation / mark-up captured images with included PC software.

    Quote AP16 with your order

    Terms and Conditions: A Lynx EVO system comprises of a head, zoom, stand, objective and ring light or 360 degree rotating viewer. Promotion runs from 11/1/2016 to 12/22/2016, orders must be placed by 12/22/2016. Distributor orders to be drop shipped. Not to be combined with any other offer. Offer available while stocks last.

     


    OFFER 2

    ½ Price 360o Rotation Viewer with Lynx EVO or EVO Cam system purchase- $1,935* savings

    Enhance your inspection with the 360o rotating viewer, at 50% off.
    The rotating viewer for the Lynx EVO and EVO Cam delivers an oblique view of the subject that can be rotated 360° degrees around a central point, making it ideal for working with evo-cam_-2 evo-camengineered, electronic, or precision parts – the fastest, simplest way to inspect all the way around a component without holding it.

    • Easy to switch between rotation view and conventional direct view.
    • View all around a component, quickly and accurately.
    • Ideal for electronics inspection (PCB solder joints, holes, pillars and thread forms), mechanical, medical and plastics components and more…
    Terms and Conditions: A Lynx EVO system comprises of a head, zoom, stand, objective and ring light. An EVO Cam system comprises of camera, stand, objective and ring light. Promotion runs from 11/1/2016 to 12/22/2016, orders must be placed by 12/22/2016. Distributor orders to be drop shipped. Not to be combined with any other offer. Offer available while stocks l

    *savings based on EVO Cam 360o viewer RRP.
    Quote AP16 with your order

  • Is Water Harmful to Electronic Components?

    hose-spraying-waterMany experts in the electronics assembly world will cringe when they hear about a manufacturer hand-washing their boards with soap and (gasp!) water. The first point to bring up here is that boards should never need to be washed. This is a clear indication that you are somehow bringing dirt into the process, whether through alcohol, brushes, or something else the boards are coming in contact with.

    Know Your Water Grade

    There are three grades of water that you can use to clean the boards; tap water, distilled water, and deionized (DI) water. For this type of precision cleaning you should never use tap or distilled water, which themselves contain contaminants that can affect your boards. If you must clean your boards with water, the only choice is deionized water.

    Deionized water is measured by the water’s resistance to electric current. 50kOHM is standard and can be purchased easily and at a relatively low cost. 1 megaohm is really the minimum required for this type of precision cleaning. In high-precision manufacturing, such as semiconductors, 20 megaohms is the industry standard. Obviously cost and availability are both big factors. As you increase the pureness of your water, it also becomes more difficult to handle.

    One option is a sealed, closed-loop system which purifies the water, performs the cleaning task, and then recycles the water. However, this type of system is costly and can result in a slow through-put. Given these restrictions when using water in the cleaning process, more and more manufacturers are switching to cleaning with solvents. The ideal solvent is strong enough to remove the contamination, while still mild enough to not damage any components on the board.

    GoKimco has a complete line of solvents, ideal for finding this healthy balance for cleaning your boards.

  • Gauging Solder Paste Volume

    stencil-printingKnowing just how much solder paste to dispense onto a stencil for a production run can often seem like a guessing game. The ultimate goal is for the paste to completely fill the aperture and release onto the board with 95% transfer efficiency. If the board is not sitting flush again the stencil, then you may see a greater than 100% transfer efficiency. This can lead to a final paste height that is higher than anticipated. Too little solder paste, and you risk not covering the board entirely, leading to an array of problems.

    The amount of paste that you dispense onto the stencil will vary depending on the size of your production run. For a smaller number of boards, ten or under, a minimal amount of paste will be needed to achieve the smooth, rolling action that you need. For larger production cycles, you will want to apply the maximum amount of solder paste possible without loading the squeegee too high, creating flooding and spilling over the sides. A good rule of thumb is 0.75” diameter down the length of the squeegee as a minimum and a 1.5” diameter as a maximum.

    Operators should always be watching for paste leaking out of the sides of the squeegee, which can result in skip defects. Paste remaining idle during the printing process can dry out and harden faster. To prevent this, operators should be trained to open the printer regularly, every 30 minutes is a good rule of thumb, and reposition the paste to the middle of the squeegee.

    It is good practice to print one dummy board before each production run. This first run often uses an excessive amount of flux and can pick up any dust or contamination that can then be loaded into the apertures of the board. Running this test board also ensures that the paste is rolling and that the squeegee is set up properly, with no streaks left behind.

    Using a quality solder paste paired with the right squeegee can make a big different in your product run.

    GoKimco has a complete line of solder paste and quality squeegees to ensure that your production process runs as smoothly as possible.

  • Epoxy Bonding Problems on RoHS Boards

    epoxy bonding rohsIf you have seen problems with epoxy bonding components to RoHS circuit boards, you are not alone. This may be related to the surface energy of the board. Generally high surface energy is a good thing, while low surface energy is detrimental. The surface energy of the solder resist varies with the many types available. Oven curing the solder resist tends to lower the surface energy because the silicones are then forced to the surface during the curing process.

    It may be useful to perform a simple control test to investigate the surface energy of the boards. This can be done using dyne pens or a contact angle test. If you are using a dyne pen, 36 to 38 dynes is average. A no-clean, assembled board would be about 32 dynes, and you would not want to work with anything lower than this.

    To perform the contact angle test, measure the contact angle of a droplet to see how much the droplet beads up or wets out onto the surface. If when you perform the droplet test you find that the beads are quite round and do not wet this indicates low surface energy and poor bondability.

    From here you should conduct a suitable gas plasma treatment on some of the boards and see if this improves bondability and adhesion. You can bond actual parts to both the control and plasma treated boards to confirm any improvement in adhesion.

    If you are bonding to a metal surface, you should always first prep the surface with etch or alcohol. This will ensure the area is clean prior to any epoxy applications. GoKimco offers a complete lining of cleaning wipes to prep the area. Visit

    To find the best epoxy solution for your application shop GoKimco.

  • Surface Texture on Solder Joints after Reflow

    surface defects reflowSeeing surface effects when using lead-free solder is not an unusual occurrence. There are many factors that could be causing texture on the solder joints after reflow.

    The following are several of the more common factors that could be contributing to this defect:

    • Thermal profile used, peak temperature and cool down rate
    • Metal finishes on the parts that were soldered, dissolution occurs which can impact color
    • Reflow atmosphere
    • Physical or chemical properties of the flux, some fluxes react more with the solder surface than others
    • Flow properties of the flux during the reflow process, some fluxes flow more rapidly than others, giving extended exposure to oxygen
    • Excessive oxidation of the parts to be soldered
    • Shelf life of the paste or how the paste was handled prior to use

    Keep in mind that while the surface of the board may look frosty, discolored, or be demonstrating shrinkage effects this does not necessarily point to a reliability issue. Instead the solder joint may remain in excellent working condition with adequate intermetallic bonding.

    If you suspect that there may be a reliability issue associated with the appearance you will need to do some pull/shear testing to examine the bond layers. Use a quality pair of shears for the most accurate results. (http://gokimco.com/search?form_key=ViRkrOmJrsyABtEG&q=shear) If there is a problem with the bond layers, examining the reflow process for problems and / or changing to a different solder paste can correct the problem.

    GoKimco has a wide variety of solder pastes so that you are sure to find one that will sort out this issue. Visit http://gokimco.com/solder-flux-mask/solder-paste.html.

  • Why Would You Have to Clean a No-Clean Soldering Flux?

    no clean flux residueIt sounds like an oxy-moron but it is a common misconception that no-clean flux never needs to be cleaned. Many in the industry have experienced the conductive residue that can be left behind by no-clean flux. This residue can be extremely hard to remove, which becomes a big problem if you are working with sensitive boards. Because the no-clean fluxes are designed to not need to be cleaned they do not come off easily, which can be problematic.

    The amount of residue that is left on the board is dependent on several factors including the amount of solids-resins, gelling agents and activators contained in the flux. There is less flux residue left on the boards when the solids content is lower. Most of today’s no-clean flux contain between 50 and 70 percent solids.

    Despite all of this, no-clean remains the most widely used type of flux. Manufacturers are in the habit of running all of their boards with no-clean, and simply cleaning only those boards that require it.

    It may be tempting to not clean your dirty boards, simply because you are using a “no-clean” flux but this can have significant adverse effects down the road. In the past, assemblers saw problems arise with in-circuit testing on these un-cleaned boards. The residues from these no-clean fluxes also lead to malfunctions in circuits with clock speeds.

    acl staticideWhile in most cases not every board being soldered with no-clean flux will need this extra step, you do need to be on the lookout for the tell-tale residue left behind and clean these boards to prevent problems down the road. One great product for doing this is ACL Staticide 8623-12 No Clean Precision Flux Remover. This product can be purchased online at KIMCO Distribution http://gokimco.com/search?form_key=OhbYqHgT3MbeEp53&q=ACL+Staticide+8623-12+No+Clean+Precision+Flux+Remover.

  • Why Isn’t My Soldering Iron Tip Tinning?

    weller soldering ironOne of the frustrations in the electronics assembly world can be when your soldering iron tip cannot be tinned. Tinning is a necessary step for all new tips. By tinning the soldering iron tip, you can keep the tip from oxidizing. The fine coating of solder that is applied to the tip is critical to the soldering process, as the tip transfers the heat from the iron to the joint that you are trying to solder.

    The real secret to tinning your soldering iron tip lies in the timing. You need to get the coating of solder on the tip before it gets hot and begins oxidizing, which can make this process a challenging if not impossible one. To prevent this oxidation you need to act quickly and efficiently applying the solder.

    Your soldering iron tip also may not be tinning if there is an oxide layer. In this case you will need to first clean this oxidation off of the tip before the tinning process.

    Another sign that there is a problem and that you will not be able to tin the soldering iron is if the tip keeps turning black when you try to solder. Less expensive soldering irons will have a tip that is more likely to get black carbon on it, contaminating your tip with this in turn. If this is a reoccurring problem, it may be worthwhile to invest in a higher-end soldering iron which will save on productivity, not to mention operator frustration, in the long-run.

    Weller is a popular manufacturer of soldering irons that can help to eliminate this problem. The Weller TCP12P Controlled-Output Field Soldering Iron is a great choice.

    KIMCO Distributing offers a wide range of soldering irons, including those from Weller. Visit http://gokimco.com/search?form_key=OhbYqHgT3MbeEp53&q=soldering+iron to browse the soldering irons available.

  • The Power of Static Electricity and Minimizing an Electrostatic Discharge

    The Power of Static Electricity

    We’ve all experienced that little static shock between ourselves and another surface or person.  While annoying, it is a relatively harmless event. That is unless it happens in certain work environments and around sensitive electronic equipment. In these cases it can be very expensive.

    That seemingly tiny charge can cause a short or even a fusing of metals together on a circuit board. It can cause damage that the naked eye can’t see. Today’s electronics are so powerful and sensitive that in the blink of an eye, they are altered by a static charge.

    What is the Cause of Electrostatic Charges?

    An electrostatic discharge is the transfer of electrons between two objects. One surface is positively charged while the other is negatively charged.  The human skin tends to accumulate positive charges, while synthetic materials gather negative charges.

    Electrostatic charges occur three primary ways:

    • Air movement around electronic equipment. This can include spray compressed air or fans near the equipment.
    • Synthetic materials placed near electronic equipment. This can be as simple as a Styrofoam coffee cup.
    • Human contact with electronic equipment. The human body can store a surprising amount of electrostatic charge. Simply handling a circuit board can discharge it.

    Minimizing and Preventing Electrostatic Charges

    There are multiple steps you can take to prevent electrostatic charges. Making sure your facility has a single common ground is a good place to start. You can also use ESD-safe compressed air. Make an effort to keep synthetic materials away from electronic equipment. But there is a simpler way to solve issues with electrostatic charges: ESD matting.

    The Purpose of ESD Matting

    ESD Matting keeps a balance between positive and negatively charged surfaces. It is a convenient and affordable way to solve a potentially expensive problem. ESD mats come in tabletop versions and in floor mats. They come in an array of colors and sizes. If you want to assure a static free environment consider the use of ESD matting.

  • Proper Tecniques for Printed Circuit Board Cleaning

    Proper Tecniques for Printed Circuit Board Cleaning

    Printed Circuit Boards are delicate pieces of electronics and it is important that they be cleaned and maintained properly. Though many may feel that dusting a PCB is sufficient for removing potentially harmful build up, there are a few different methods for removing sediment that can help extend the life and improve performance of a PCB.

    canned-airThe first and most common item used for cleaning PCBs is canned air. This highly compressed air is great for pinpointing dust and particulates without damaging or disturbing the rest of the circuit board in the process. Using a dust rag or other, harsher cleaning agent can dislodge connections and can cause major issues down the road. Rough or abrasive cleaning can break connections and damage the circuit board to the point of replacement.

    ACL StaticideThe next cleaning agents to consider are solvents. Sometimes dusting is simply not enough to remove particulates and other dust that is on a PCB. Solvents can help to remove large deposits like corrosion, rust, solids that have formed on the surface, and other issues that can damage and even stall the function of a PCB. When choosing a solvent it is always important to choose a product that has vapor rinse. This will help to remove all residue that is left after soldering.

    There are a few different ways that residues can be removed, the first is submersion of the PCB in the proper solvent. For soldering residue, water based submersions work best. It may also be sufficient to use air based cleaning to remove these harmful build up. For tougher residues using a solvent can help.

    Branson Ultrasonic CleanerUltrasonic cleaning can help to dislodge residue without much contact. The less users have to touch the PCB to remove residue the better. Extensive handling can cause damage without truly cleaning the PCB. Because these circuit boards are so small and delicate, it is important that precision is used to remove any dirt or other sediment. Taking the time to find the proper solvent for the issue at hand can save time and money in the long run and can insure a clean and well functioning PCB.

  • Why Should my Company Switch to Lead Free Soldering?

    If circuits were living creatures, solder would be the blood cells. Without this valuable tool, many of the luxuries we take for granted (like computers, smartphones and GPS) wouldn't function. For more than a century, lead based solder has been the standard for connecting resistors and capacitors to a circuit. However, a recent rise in environmental concern has the future of lead-based solder in question. It's already illegal in Europe, and it may soon suffer the same fate in the US.

    Is Lead-Based Solder Better?

    There are many hobbyists and amateur electricians who swear by lead based solder, because they think it provides a better bond. However, a skilled worker can garner quality results from a 100% lead-free solder. Most solders have a 60/40 ratio of lead to other metals, typically tin and aluminum. However, there are completely lead-free options available and their benefits far outweigh any perceived disadvantages.

    Benefits of Lead-Free Soldering

    • Safety- The threat of lead poisoning has caused this metal's elimination from virtually every phase of modern life. Precautions can be taken to prevent workers from inhaling lead vapors, but lead-free is a safer option. The National Institute for Health (NHI) suggests avoiding lead-based soldering, so there's no debate about which type is more harmful.
    • Going Green- Products made with lead-based solder can't be recycled, which creates far more waste. Lead-based solder also contaminates the ground water when it's buried in land fills.
    • Global Commerce- Products with lead-based solder have already been outlawed in Europe. Anyone looking to capitalize in foreign markets should be using lead-free.
    • Reliability- People may think that lead-based solder is more dependable, but reliable sources at Dartmouth College say otherwise. Lead-based solder has also been outlawed in Europe since 2011, and they have yet to experience any adverse effects.

    Why is Lead-Based so Popular

    It takes time to become familiar with 100% lead-free solder. It molds differently, and it may take a day or so for you grow accustom to the change. However, there is no credible data to suggest lead-free is any less reliable. Even if it did bond better, choosing lead-based solder over lead-free is like replacing the graphite in pencils with lead because it writes better. That one minor benefit is heavily outweighed by the bounty of benefits provided by the safer alternative. In general, people are typically opposed to change, but this is a simple decision to save the lives of those who build circuits and improve the health of the environment.

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