MOUNTING METHOD AT WAFER LEVEL

PROBLEM TO BE SOLVED: To provide a mounting method at wafer level for a simplified process by appropriately forming a stress buffer layer on a wafer instead of an underfill. SOLUTION: A patterned photoresist is formed on a wafer 100 so as to cover a bump formation position and a plurality of scribe lines. A stress buffer layer 109 is formed on a region not covered with the photoresist. After the photoresist is removed, a plurality of first openings are provided on the stress buffer layer 109. The stress buffer layer and the scribe line are covered with a stencil comprising a plurality of second openings 115 or a second patterned photoresist 114. The first opening is exposed at the second opening, which is filled with a solder material 116 for a reflow process. Then the stencil or the second patterned photoresist 114 is removed. A wafer packaged like this is directly connected to an external carrier after dicing.