Ensuring A Robust Connection between the SSD's Integrated Circuits and the PCB
Underfill technology, an innovative solution, effectively addresses several limitations associated with high-bandwidth ball grid arrays (BGAs). These BGAs are commonly used to establish connections between essential components such as memory integrated circuits (ICs) and NAND flash controllers in modern solid state drives (SSDs). While BGAs are well-suited for static applications like workstations and servers, their susceptibility to mechanical stressors in dynamic environments can lead to significant malfunctions. Industries exposed to these stressors, including mission-critical operations, industrial automation, edge computing, and transportation, recognize the value of underfill technology.
Mitigating Challenges with BGAs: Fracture Risks and Tin Whiskers
Solder balls, acting as a critical link between PCB substrates and integrated circuits, are prone to fractures when subjected to mechanical and thermal stresses. These fractures inevitably result in complete device failures. Moreover, the emergence of tin whiskers—a phenomenon where hair-like projections grow from solder materials over time—presents another concern. This phenomenon can lead to short circuits within BGAs, especially in high-stress environments.
Epoxy Bonding for Enhanced Durability
Exascend employs underfill technology to provide a robust solution to mitigate the likelihood of BGA-related malfunctions. By employing epoxy bonding, integrated circuits are securely affixed to the PCB. This involves applying epoxy to create a protective layer around the solder balls that form the IC-PCB connection. The result is a resilient connection that is significantly less susceptible to factors such as friction, shocks, and thermal expansion. Additionally, the application of underfill significantly reduces the space available for tin whiskers to develop, effectively minimizing the risk of short circuits arising from this phenomenon.
Implementation in Exascend SSDs
In Exascend’s SSDs featuring underfill technology, a specialized dispenser is employed to apply epoxy resin in close proximity to all ICs attached to the PCB via BGAs. Through capillary action, the epoxy spreads throughout the entire BGA, enveloping and safeguarding all connections. The subsequent step involves subjecting the Exascend SSD to a heat-curing process using dedicated equipment. This meticulous procedure ensures the epoxy resin reaches a solid, dependable state. Once the epoxy achieves complete curing, the Exascend SSD is poised for subsequent stages, which might encompass the application of a conformal coating or final deployment within the customer’s designated application.
Shielding the entire SSD against moisture and contaminants.
Ensuring a robust connection between the SSD’s integrated circuits and the PCB.
Providing IP-rated resistance against dust and water.
MIL-STD-810-compliant flash storage for extreme environments.