Evaluation of Cu capping alternatives for polyimide-Cu MCM-D

Conference PaperinProceedings - Electronic Components and Technology Conference · February 2001with1 Read
DOI: 10.1109/ECTC.2001.927977 · Source: IEEE Xplore
Conference: Electronic Components and Technology Conference, 2001. Proceedings., 51st

    Abstract

    Among the 3 types of polyimide (PI) systems, pre-imidized,
    polyamic ester and polyamic acid, the latter has been shown to react
    with Cu surfaces when it is spun coated. This paper reviews Cu-polyimide
    adhesion and diffusion data and present various wet process alternatives
    to minimize Cu diffusion into poly(biphenyl dianhydride-p-phenylene
    diamine) (BPDA-PDA) polyamic acid precursor. Two different process
    options were investigated: a precoat or adhesion promoters (A1100, AP420
    and benzotriazole) prior to the polyamic acid apply, and an additive
    (Tetrazole or BTA) formulated in the PAA solution. The 5 processes were
    compared with respect to adhesion, capacitance, dielectric constant and
    reliability. Only the BTA formulation had adhesion problems which were
    attributed to the A1100 precoat used. A1100 as a precoat was further
    evaluated on various copper surfaces and curing environments. All
    proposed solutions performed well when used on a MCM-D/C module which
    was used to extract electrical parametrics and was further subjected to
    reliability testing