Method of forming an apparatus to reduce thermal fatigue stress on flip chip solder connections
AssigneeInternational Business Machines Corporation
InventorsDavid J. Alcoe, Eric A. Johnson, Matthew M. Reiss, Charles G. Woychik
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Abstract
The present invention provides a package for a semiconductor chip that minimizes stresses and strains that arise from differential thermal expansion on chip-to-substrate or chip-to-card interconnections. A collar element of one or more elements is provided. Adhesive material connects the collar element to the electric device and to the substrate that supports it, forming a unitary electrical package.
Claims21
An electrical package comprising:
- a) a substrate comprising an upper surface, said upper surface further comprising at least one electrical circuitry connecting pad;
- b) an electric device having a first modulus of elasticity and comprising upper and lower major surfaces separated by a predetermined thickness, said major surfaces defining a shape bounded by a perimeter, and said device comprising at least one connection region on said lower major surface;
- c) at least one flexible connector linking said at least one connecting pad to said at least one connection region;
- d) a collar element having a second modulus of elasticity and a first dimension and a second dimension, said first dimension comprising a length less than said device perimeter and at least a portion being bonded to said perimeter, and said second dimension being bonded to said substrate upper surface;
- and
- e) an adhesive material having a third modulus of elasticity no greater than said second modulus of elasticity, said adhesive material adhering to at least a portion of said second side of said collar and to a portion of said upper surface of said substrate, thereby creating a unitary electrical package comprising said device, said substrate and said collar.
A manufacturing intermediate for an electrical package comprising:
- a) an electric device having upper and lower major surfaces separated by a predetermined thickness, said major surfaces defining a shape bounded by a perimeter, and said device comprising at least one connection region on said lower major surface;
- b) a collar element having a first dimension and a second dimension, said first dimension comprising a length less than said device perimeter, and at least a portion being bonded to said perimeter, said collar element being attachable to a substrate;
- and
- c) a bond between at least a portion of said perimeter and said first dimension creating a unitary intermediate manufacturing electrical package comprising said device and said collar element.
A process for manufacturing an electrical package, the steps comprising:
- a) providing a substrate having a major surface and at least one electrical circuitry connecting pad disposed thereon;
- b) aligning an electrical component relative to said substrate;
- c) positioning at least one collar element relative to said substrate;
- and
- d) bonding said electrical component and said at least one collar element to said substrate.
Dependencies are inferred from the claim text.