US 5,296,736 AGranted

Leveled non-coplanar semiconductor die contacts

AssigneeMotorola, Inc.

InventorsJohn K. Frei, Howard D. Knuth, Bruce R. Tegge

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Abstract

A semiconductor assembly which includes a carrier and a semiconductor die is mounted on a printed wiring board. The die includes a top active surface and a bottom active surface. The two active surfaces are non-coplanar. The carrier is made from layers of a ceramic material. Holes are formed through all but one of the layers. The layers are laminated into an integral substrate, and the substrate is fired. The holes form a cavity into but not through the substrate. The number of layers, lamination pressures, and firing parameters are all adjusted in response to the thickness of the die to insure that the height of cavity walls approximately equals the thickness of the die. Continuous metallization is applied in the cavity and on a top surface of the substrate. The die is bonded in the cavity, and conductive bumps are formed on the die and the metallization.

Claims16

Dependent claims

A carrier for substantially leveling non-coplanar semiconductor die contacts, said carrier comprising:

a substrate having an external surface and a cavity therein, said cavity being bordered by cavity walls of said substrate that extend from said external surface a predetermined distance into an interior of said substrate and being bordered by a cavity floor of said substrate that extends between said cavity walls;
an electrically continuous conductive layer having a first portion overlying said cavity floor, a second portion on said cavity walls, and a third portion on said external surface such that said first portion is electrically coupled to said third portion via said second portion of said conductive layer;
a semiconductor die having first and second active contacts located respectively on first and second non-coplanar surfaces, and wherein said cavity is dimensioned so that said semiconductor die fits within said cavity, said first active contact being electrically coupled to said first portion of said conductive layer, and said second active contact being approximately co-planar with said third portion of said conductive layer;
and
a first conductive bump positioned on said third portion of said conductive layer, said first conductive bump being electrically coupled to said first active contact of said semiconductor die by said conductive layer.

2 more elements

An assembly having substantially planar contacts, said assembly comprising:

a substrate having an external surface and a cavity therein, said external surface being substantially flat and residing in a plane, said cavity being bordered by cavity walls of said substrate that extend from said external surface a predetermined distance into an interior of said substrate and being bordered by a cavity floor of said substrate that extends between said cavity walls;
a substantially continuous conductive layer having a first portion overlying at least a portion of said cavity floor, a second portion on at least a portion of said cavity walls, and a third portion on a portion of said external surface such that said first portion is electrically coupled to said third portion by said second portion;
a die having first and second active contacts, located on first and second non-coplanar surfaces respectively, said semiconductor die residing within said cavity so that said first active contact is electrically coupled to said first portion of said conductive layer and said second contact is approximately co-planar with said third portion of said conductive layer;
a first conductive bump positioned on said second active contact of said die;
and
a second conductive bump overlying said third portion of said conductive layer, said second conductive bump electrically coupled to said first active contact of said semiconductor die by said conductive layer.

3 more elements

Dependencies are inferred from the claim text.