Monthly Archives: September 2016

  • 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.

  • Meet our team: Nate Lelle - Customer Service Wizard and Paintball Champion

    Nate Lelle is the customer service wizard here at Kimco, but you might not know that he is also a nationally ranked paintball player, and member of the renowned Cleveland Imperial semi-pro paintball team. Kimco is proud to sponsor Nate and the Cleveland Imperial team, which has had many top finishes at top level events all over the country. Nate brings the same passion he shares for paintball to his work providing you the best customer service Kimco has to offer.

    Check out Cleveland Imperial here:

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