Integrated circuit die package stiffeners of metal alloys having exceptionally high CTE
US12183688B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 2021 |
| Grant date | Dec 31, 2024 |
| Priority date | — |
| Expiry date | May 4, 2043 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K7/1461
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A stiffener for an integrated circuit (IC) package assembly including an IC die electrically interconnected to a substrate. The stiffener is to be mechanically attached to the substrate adjacent to at least one edge of the IC die and have a coefficient of linear thermal expansion (CTE) exceeding that of the substrate. The stiffener may be an “anti-invar” metallic alloy. Anti-invar alloys display “anti-invar” behavior where thermal expansion of the material is significantly enhanced relative to other compositions of the particular alloy system. A package stiffener may be a high-Mn steel, for example, such as ASTM International A128. In other examples, a package stiffener is a MnCuNi, FeNiMn, or FeNiCr alloy having an average CTE over a range of 25-100° C. of at least 18 ppm, and a room temperature modulus of elasticity of at least 120 GPa.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.