Know More about SMT Adhesive

Posted by Alphaassembly on November 28th, 2016

SMT adhesives are used for holding the bottom side, and in some cases, mixed technology surface mount parts during the wave soldering processing. SMT stands for ‘surface mount technology’ and it is   one of the modern methods used for manufacturing electronic circuits by mounting the components or placing them directly onto a printed circuit board’s surface. PCB manufacturers and electronics assembly specialists require a high-quality and reliable SMT adhesive to make sure that the components stay in place without any damage to them and to the printed circuit board. Here are some of the things you must know about an SMT adhesive:

•    Specially formulated for electrical applications – High-quality SMT adhesives have excellent electrical characteristics, good adhesion to substrate, resistance to humidity, and reliable wet strength. The best adhesives are non-stringing and non-slumping for a more consistent and precise dot profile. They cure fast, too, so you do not have to wait a while before proceeding to the next step in production.

•    SMT adhesives are versatile – You can use them to hold passive and some active components. They can be used to bond SMDs (surface mount devices) to the PCB, too, so you can form the joint between the SMD’s body and the bare FR-4 or solder resist between solder pads. That way, components will not be displaced from their respective positions especially during the high-speed installation of passive components. Some SMT adhesives are formulated to suit laser stencil print and pin transfer applications as well.

•    It can be used with dispensing equipment – To avoid manual work, electronics assembly companies use specialized dispensing equipment to ensure a consistent and precise placement of the SMT adhesive in the shape of a dot, with different volumes to suit the various sizes of devices being assembled.

•    They are easy to see – SMT adhesive is often dyed in colors that are easy to spot, like yellow or red. That way, you know exactly where it is applied.

•    Extended shelf life – High-quality SMT adhesive remains stable in room temperature and can be stored for up to six months in the same conditions.

•    Cure profile – You need to make sure that the correct thermal profile is maintained to let the adhesive achieve a homogeneous cure and its maximum mechanical strength. The material must be heated to the right temperature for a specific time, and keep the maximum thermal ramp rate to 1.5 to 2 degrees Celsius per second to ensure that the cure is homogeneous.

About the Author:

Alpha Assembly Solutions is a premier company engaged in the development and manufacture of high quality electronics assembly materials. Since the year of its inception, way back in 1872, the company has played its role on the frontline of innovation, bringing many first-to-market products to the fore thereby, creating a premier niche for itself in the market.