Abstract: A heat exchanger panel assembly includes two panels, one with milled channels approximately in cross-section which flow coolant, and the other a close-out nominally flat panel which is bonded to the tops of the ribs of the milled channel with a thin interlayer of a transient liquid phase (TLP) bonding agent foil as the bonding interface. The method of manufacture provides transient liquid phase bonding coupled with vacuum compression. The bonding is accomplished by vacuum compression at elevated temperature in a furnace in which a vacuum is impressed on the channels while high pressure is forced on the panel exterior which forces all bonding interfaces into intimate contact.

Abstract: An apparatus and method may be used for welding a first panel to a second panel, the first panel having an inboard side partially contacting the second panel and an opposite outboard side. The apparatus has a welding beam generator. The apparatus reduces a pressure along the inboard side of the panel relative to an adjacent pressure along the outboard side so as to produce inward deflection of the first panel along a first portion of the first panel not contacting the second panel relative to a second portion. The apparatus has locates, based on said deflection, at least one of said first portion or said second portion.