Patent ID: 8829661
Filing Date: 2014-09-09
Classification: H01L,H05K

Abstract:
1. A method for forming an electrical assembly, comprising: providing multiple electronic devices with primary faces where electrical contacts are located, opposed rear faces, and edges extending between the primary and rear faces; providing a perforated warp control sheet having multiple openings therein sized to accept the multiple electronic devices and having a first coefficient of thermal expansion (CTE); providing a temporary support adapted to receive the multiple electronic devices and the perforated warp control sheet on a principal surface thereof; then in either order, placing the perforated warp control sheet and the multiple electronic devices on the principal surface of the temporary support, with the multiple electronic devices in the openings in the perforated warp control sheet so that gaps are located between the edges of the electronic devices and edges of the openings in the perforated warp control sheet, and wherein the primary faces of the electronic devices are oriented toward the principal surface of the temporary support; providing plastic encapsulation material at least in the gaps, wherein a characteristic of the plastic encapsulation material is that a second CTE of the plastic encapsulation material is equal or greater than the first CTE; curing the plastic encapsulation material, wherein the characteristic that the second CTE is equal to or greater than the first CTE results, after curing, in a panel containing the multiple electronic devices and the perforated warp control sheet having a convex warp wherein a first surface of the panel at which the primary faces are exposed has a convex curve; and separating the devices, the perforated warp control sheet and the plastic encapsulation in the gaps from the temporary support, thereby providing the panel containing the multiple electronic devices and the perforated warp control sheet joined by the plastic encapsulation.