摘要 |
A method and structure for isolating a die from thermally induced or pressure induced differential stresses between a die and a package includes providing an intermediate layer having therein a plurality of relief channels arranged to provide a flexure for absorbing such differential stresses. The relief channels define interior and peripheral portions of the intermediate layer, and the die is typically mounted on the interior portion. The peripheral portion of the intermediate layer is then bonded to the package. The channels may be disposed along both the upper and lower surfaces of the intermediate layer, or may be disposed on only one surface. Likewise, the channels may be disposed along one or both of the length and width of the upper or lower surfaces. Reservoir channels may also be provided to prevent adhesive from flowing and bridging the relief channels. Other relief channel patterns may be implemented for other designs, including a checkboard pattern of relief channels on one side of an intermediate layer, to provide vertical stiffness and horizontal compliance. |