Soldering - MEDER BGA Series

Soldering Approaches for MEDER CR Series

Ever since the introduction of surface mount technology, components have gotten smaller and smaller, making it more challenging for the interconnect from the component to the PCB. With smaller and smaller components having higher and higher pin counts, the problem has become even more complex. While conventional approaches are still used, Ball Grid Arrays (BGAs) have become a popular way of dealing with this issue; but care must be taken, as we will present in detail in the following application note. We will focus on both approaches, discussing their advantages and challenges as it relates to soldering our CRF, CRR and RM relay series onto a substrate.


Soldering Challenges

PCBs have varying degrees of Thermal Coefficient of Expansions (TCEs). These TCEs often are much greater than the components to be connected. Also, the TCEs will differ for a PCB in its different planes or axes; and in many cases the plane on which the component is to be mounted has the highest TCE. Solder, being very malleable, will tend to absorb some of the movement of the component vs. the PCB during temperature excursions. With continuous temperature cycling, solder joint fatigue can develop, creating a rift or crack in the solder joint. Many variables play into this, some of which are: size of components, TCEs of the PCB and component, component plating and its thickness, PCB plating and its thickness, thickness and shape of the solder between the component and the PCB, expected number of temperature excursions including min and max temperatures, etc. ...

MEDER BGA Series Brochure