Patent ID: 8637992
Filing Date: 2014-01-28
Classification: H01L

Abstract:
1. A microelectronic package, comprising: a substrate having a first surface and a plurality of substrate contacts at the first surface; a microelectronic element having a front surface and contacts arranged within a contact-bearing region of the front surface, the contact-bearing region entirely located within a middle third of a distance between first and second opposed edges of the front surface, the front surface having first and second peripheral regions between the contact-bearing region and the first and second opposed edges, the contacts facing the substrate contacts and joined thereto; an underfill disposed between the substrate first surface and the contact-bearing region of the front surface of the microelectronic element, the underfill reinforcing the joints between the contacts and the substrate contacts, wherein the underfill does not contact the first and second peripheral regions; and a joining material having a Young's modulus less than 75% of a Young's modulus of the underfill and bonding the substrate first surface with the front surface of the microelectronic element.