The present invention stacks integrated circuit packages into circuit modules. In a preferred embodiment, solder paste and primary adhesive respectively are applied to selected locations on the flex circuitry. Supplemental adhesive is applied to additional locations on the flex circuitry, CSP, or other component. The flex circuitry and the CSP are brought into proximity with each other. During solder reflow operation, a force is applied and the CSP collapses toward the flex circuitry, displacing the primary adhesive and the supplemental adhesive. The supplemental adhesive establishes a bond providing additional support to the flex circuitry. In another embodiment, CSPs or other integrated circuit packages are bonded to each other or to other components with a combination of adhesives. A rapid bond adhesive maintains alignment of the bonded packages and/or components during assembly, and a structural bond adhesive provides additional strength and/or structural integrity to the bond.