Role of Adhesives in the Assembly of Circuit Boards
Whether you’re building a new phone or buying one to use in the office, you rely on adhesives for your electronic devices to function. From encapsulating components to conformal coating, these specialty adhesives are used in numerous applications across the circuit board assembly process. Without the right adhesive materials, electronics may experience vibration or movement that could damage delicate parts or lead to a product failure. Adhesives in electronic assembly serve several key functions, including bonding components to the printed assembled circuit board (PCB), preventing vibration, and protecting sensitive surfaces.
A critical component of the electronic industry, a solid understanding of the role adhesives play in the assembly of electronic devices is essential for manufacturers to achieve high quality results. This includes understanding the chemistry of surfaces, how that influences adhesion outcomes, and how to optimize manufacturing processes for optimal adhesion and assembly outcomes.
The most popular types of adhesives in the electronic industry include epoxy, acrylic, and hot-melt. All three are commonly used in the manufacturing process and offer a range of benefits. Hot-melt adhesives are particularly useful for the PCB manufacturing process because they bond quickly to metal or plastic components. They also work in harsh environments and provide excellent resistance to heat, moisture, and chemicals.
The Role of Adhesives in the Assembly of Circuit Boards
Acrylic and epoxy adhesives are also frequently used in the manufacturing process of PCBs. Both are often formulated to withstand the temperature and humidity conditions in manufacturing plants, and both are available in different formulations that provide various levels of flexibility and resistance to heat. In addition, acrylic and epoxy adhesives are typically easy to dispense, curing in seconds, making them ideal for fast-paced production lines.
Another common type of adhesive in the electronics industry is red glue, a polyolefin that is able to withstand high temperatures and has low moisture content. Red glue is commonly used for the assembly of flexible circuit boards because it combines flexibility with the ability to bond different materials, including copper and plastic layers. This helps to ensure that the stiffeners on a flexible circuit board will remain in place and prevent it from breaking.
In addition to bonding the components of a circuit board together, electronic adhesives are often used for additional purposes such as conformal coating and wire tacking. Conformal coatings are sprayed on top of electronic devices to protect them from dust, dirt, and moisture. These protective coatings can also help keep out noise, light, and electromagnetic fields.
Lastly, electronic adhesives are also used to hold surface-mount components in place on the printed circuit board before soldering. This prevents them from moving during the solder reflow process, reducing the likelihood of misalignment and defects.
As technology advances, more and more products rely on adhesives instead of mechanical fasteners. This increase in reliance on glues means that manufacturers must have an accurate understanding of how varying surfaces and environmental conditions impact adhesion outcomes, and be prepared to make adjustments when necessary. Having the ability to measure and monitor surface conditions in-process is the best way for manufacturers to avoid costly mistakes and ensure their products will meet consumer demand.