Abstract: A screen for brazing a heat exchanger including a plurality of core plates and a base plate. The plurality of core plates may be formed from an aluminum alloy brazing sheet containing magnesium and may have a shape having a taper portion at a periphery. The base plate may be larger and thicker than a core plate of the plurality of core plates. The plurality of core plates and the base plate may be heated and brazed under an inert gas atmosphere. The screen may include a metal tube enclosing a stacked body of the plurality of core plates. The tube may follow the outer border of the plurality of core plates such that a specific minute gap is defined between an inner wall face of the tube and a tip edge of the taper portion.

Abstract: A brazing sheet may be used for brazing under an atmosphere of an inert gas without flux. The brazing sheet may include at least three layers. The at least three layers may include a core material, a brazing material layer, and an intermediate layer. The at least three layers may be cladded by an outermost layer of the brazing material layer. The intermediate layer may be disposed on a face of the core material. The core material may be composed of a first aluminum alloy including at least one of (i) 0.20 weight % to 1.0 weight % of Cu, (ii) 0.8 weight % to 1.8 weight % of Mn, and (iii) 0.25 weight % to 1.5 weight % of Mg. The intermediate layer may be composed of a second aluminum alloy including 0.20 weight % or less of each of Si and Fe and 0.10 weight % or less of each of Cu, Mn, and Cr.