Authored several sections and chapters on circuit assembly for industry handbooks. President of Colab Engineering, LLC a consulting agency specializing in electronics manufacturing, root-cause analysis and manufacturing improvement. If not, encourage CMs to follow storage standards, ensure PCB assembly cleanliness is strict, store and ship PCBs and PCBAs in dry packets, and do whatever else you can to make sure your boards and products are of the highest quality.A thirty year veteran of electronics assembly with major OEMs including Digital Equipment Corp., Compaq and Hewlett-Packard. Overall, you need to make sure you have quality suppliers that follow these protocols. As mentioned above, the environment should be kept at 85% RH and temperature ≤ 30☌ (86☏). This is important to maintain not only during storage but also during shipping. PCBs should always be stored in a controlled environment, meaning extreme temperature variations need to be avoided at all costs.
They also must be dry and vacuum-sealed to protect the PCBs from ESD and corrosion.
All your PCBs must be stored in moisture barrier bags with desiccant pouches to keep moisture and humidity at bay. An additional benefit is that MBBs protect your PCBs from static. These bags feature film layers that are specialized and will control moisture absorption rate. Moisture barrier bags will enclose your PCBs in a plastic or metallic shield that will keep your boards moisture free. Store PCBs in Moisture Barrier Bags (MBB) So, whenever possible, use non-moisture sensitive components. Components that are sensitive to moisture will last a day to a year before assembly. SMD components that are not sensitive to moisture will have a virtually limitless lifetime if they’re stored in environments with ≤85% relative humidity and temperatures ≤ 30☌ (86☏). Whenever Possible, Use Components Not Sensitive to Moisture Each surface finish also has a recommended shelf life which we will go into later in this article. During this period, you must protect PCBs against contamination and oxidation by using an appropriate surface finish during fabrication. Surface Finish During FabricationĪfter bare boards are fabricated, they may require temporary storage before they are assembled. That’s where PCB storage guidelines come in and why it’s so important to follow them. If you wish to enjoy the full benefits and return on investment, you need to take protective actions both during and after production to make sure the shelf life of PCBs and their components is guaranteed. PCB design and development can be quite intensive, which means you invest a lot of your time and money into it.
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