Sample preparation method and test method of layer-adding adhesive film for FCBGA packaging substrate

The invention discloses a layer-adding adhesive film sample preparation method and a test method for an FCBGA packaging substrate, and the sample preparation method comprises the following steps: providing at least two layer-adding adhesive films for the FCBGA packaging substrate, each layer-adding adhesive film comprising a first film layer, a layer-adding adhesive film layer and a second film layer which are stacked in sequence; respectively tearing off the first film layer of each layer-adding adhesive film to expose the layer-adding adhesive film layer, oppositely superposing the sides, exposed with the layer-adding adhesive film layers, of the two layer-adding adhesive films, and placing the superposed layers on a substrate to complete sample pre-stacking; pressing the pre-stacked samples, and baking the pre-stacked samples; the baked sample is cut in a special-shaped staggered cutting mode; and stripping the second film layers on the two sides of the cut sample to obtain a sample to be detected. Therefo