Highly reliable and manufacturable ultrafine pitch Cu-Cu interconnections for chip-last embedding with chip-first benefits Article

Kumbhat, N, Choudhury, A, Mehrotra, G et al. (2012). Highly reliable and manufacturable ultrafine pitch Cu-Cu interconnections for chip-last embedding with chip-first benefits . IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY, 2(9), 1434-1441. 10.1109/TCPMT.2012.2192120

cited authors

  • Kumbhat, N; Choudhury, A; Mehrotra, G; Raj, PM; Sundaram, V; Tummala, R

authors

abstract

  • Flip-chip packaging of Ultrafine pitch integrated circuits aggravates the stress-strain concerns as the interconnection pitch is decreased, requiring a fundamentally different system approach to interconnections, underfill processes and interfaces, and the substrate. This paper demonstrates an innovative and manufacturable solution to achieve excellent reliability at Ultrafine pitch (∼ 30μ m) using direct copper-copper (Cu-Cu) interconnections with adhesives. A number of 30-μm bump pitch test vehicles (TVs) were designed with 3 mm × 3 mm chips to extract both daisy chain resistance and single-bump resistance data. Assembled bump resistivity was found to be ∼ 3-4× lower than most solders. Performance of these TVs was studied for high temperature storage (HTS) life test, unbiased-highly accelerated stress test (U-HAST) and thermal cycling test (TCT). Test results showed that the assemblies with this next generation interconnection technology depicted excellent reliability results in HTS, U-HAST, and TCT tests. Based on these results, it is concluded that adhesive materials, provide unique opportunities for Ultrafine pitch and high performance interconnections. © 2011-2012 IEEE.

publication date

  • September 14, 2012

published in

Digital Object Identifier (DOI)

start page

  • 1434

end page

  • 1441

volume

  • 2

issue

  • 9