Differential multi-flow control nozzles, apparatus and process

摘要

Process, apparatus and nozzle device are available for controlling the soldering/and or desoldering of a land grid array (LGA) component and corresponding circuit grid present in the surface of a printed circuit board (PCB). The nozzle device comprises a vacuum cup for supporting the LGA parallel to the PCB, with the LGA and the circuit grids in contact or slightly spaced, a device for directing a continuous flow of an inert hot gas, such as nitrogen, from a gas source against the upper surface of a dielectric body of a component to conduct heat therethrough to melt an underlying LGA, vents for venting the major volume of the hot gas, adjacent the upper surface of the body of the component, and one or more vertical passages for directing a minor volume of the total gas flow from the upper surface of the component around the edges, under and horizontally through the array into a discharge chamber, and out a gas outlet. A thermocouple preferably is located at the gas outlet for sensing the temperature of the minor volume of the hot outlet gas and regulating the process, thereby avoiding exposing the melted array to the possibly disruptive force of the total hot gas flow.