US 2001/0024839 A1 · Bumpless flip chip assembly with strips-in-via and plating

Abstract

A flip chip assembly, and methods of forming the same, including a single or multi-layer substrate having a plurality of via holes or apertures of which pre-formed strips or wires inside the via holes serve as the connections between the semiconductor device and substrate circuitry. The assembling steps may include attaching an integrated circuit (IC) chip or chips to a rigid or flexible substrate circuitry having a plurality of pre-formed strips extended from the patterned circuitry and hanging inside a plurality of through holes. These through holes are aligned and placed on top of the terminal pads so that the respective traces on the substrate can be connected with the respective input/output terminal pads of the IC chip through the leads inside the via holes. After attachment, electrically conductive material is subsequently connected to these leads to the IC terminal pads through electrolytic plating, electroless (chemical) plating or solder re-flow processes. The joining material can provide mechanical support as well as electrical continuity between IC chip and the circuitry of the substrate.

Claims21

Dependent claims

A flip chip assembly, comprising:

(a) a dielectric substrate having a plurality of via apertures;
(b) said dielectric substrate having first and second opposite surfaces and a plurality of electrically conductive traces being formed on the first surface of the said dielectric substrate, each one of said traces extend into a specific via aperture through at least one lead fabricated on the top of and bent into said via aperture;
(c) a semiconductor device having a first surface and a plurality of input/output terminal pads with a stack of metal film formed thereon;
(d) said second surface of said substrate engages said semiconductor device, wherein the via apertures of said substrate are aligned on the top of said terminal pads so that at least one of said terminal pads can be at least partially exposed through said via aperture from said first surface of said substrate;
and
(e) an electrical continuity of said substrate to said semiconductor device is achieved by depositing conductive material on said bent leads of the substrate as well as on said terminal pads of said semiconductor device, thereby jointly forming an integral part in the flip chip assembly.

3 more elements

Dependencies are inferred from the claim text.

Bumpless flip chip assembly with strips-in-via and plating

Life of this patent

Bumpless flip chip assembly with strips-in-via and plating

Life of this patent

Abstract

Claims21