SOLDERBALL PIN~TM TECHNOLOGY

摘要

We will detail the theory and qualification of a new interconnect with integrated Solderball Pin~TM technology that enables efficient automated manufacture of surface mount PCB subassemblies, such as board-mounted point of load power modules. Power modules manufactured as a printed circuit board (PCB) subassembly are parallel stacked to a customer's host PCB. These modules are representative of many other motherboard/daughterboard assemblies that require interconnects with a high degree of mechanical and electrical integrity. Managing coplanarity variances between the PCB modules and motherboards during the final assembly process is critical to ensure that all contact points form robust solder joint connections. Solderball Pin~TM technology employs a highly conductive copper pin that incorporates an integrated solder ball that interfaces to the host PCB. Solderball~TM pins add two important attributes to parallel stacked assemblies by providing additional solder and allowing the sub-assembly to drop slightly when the solder becomes liquid. This drop occurs when the weight of the upper mezzanine PCB module overcomes the buoyancy of the molten solder, made possible by the enhanced pin to solder ball design. These two attributes allow Solderball? Pin technology to automatically compensate for PCB co-planarity [1] variances up to .015"during solder reflow. The inherent design of solderball pins allows designers of PCB-based modules complete flexibility to determine the optimal pattern and positioning of individual interconnects. Therefore, engineers are able to maintain design and layout consistency between new SMT versions and through-hole versions, ensuring a smooth roadmap of evolutionary product offerings and surface mountable product options. Power modules or other PCB-based daughter-board assemblies that are manufactured using solderball pin~TM interconnects can be delivered to OEMs or contract manufacturers as surface mount components that are ready for assembly into the customers' final products using standard automated placement and SMT reflow soldering methodologies.