Back to results
US 9,756,738 B2Granted
Redistribution film for IC package
OwnerDyi-Chung Huinventor
Life of this patent
Estimating the term…
Abstract
A redistribution film for IC package is disclosed, which comprises a top redistribution layer configured on top of a bottom redistribution layer. The top redistribution layer is fabricated following PCB design rule, and the bottom redistribution layer is fabricated following IC design rule. Further, the interface between the top redistribution layer and the bottom redistribution layer is optionally made roughed to increase bonding forces therebetween.
Claims18
A fabricating process for a redistribution film for IC package, the process comprising:
- applying a release layer on top of a temporary carrier;
- applying a seed layer on top of the release layer;
- applying a first patterned photoresist on top of the seed layer;
- forming a plurality of bottom metal pads over the seed layer and in the first patterned photoresist;
- stripping the first patterned photoresist;
- forming a bottom redistribution layer, layer by layer, according to IC design rule and using the plurality of bottom metal pads as a start point, the bottom redistribution layer including
- a plurality of first conductive layers, wherein a top first conductive layer among the plurality of first conductive layers includes a plurality of first top metal pads exposed on a top surface of the bottom redistribution layer, and
- a plurality of first conductive vias coupling the plurality of first conductive layers to each other and to the plurality of bottom metal pads;
- and
- after said forming the bottom redistribution layer, forming a top redistribution layer, layer by layer, according to PCB design rule, directly on top of the bottom redistribution layer and using the plurality of first top metal pads as a start point, the top redistribution layer including
- a plurality of second conductive layers, wherein a top second conductive layer among the plurality of second conductive layers includes a plurality of second top metal pads exposed on a top surface of the top redistribution layer, and
- a plurality of second conductive vias coupling the plurality of second conductive layers to each other and to the plurality of first top metal pads,
- wherein, in a thickness direction in which the top redistribution layer is stacked on the bottom redistribution layer, a thickness of each of the plurality of second conductive layers is greater than a thickness of each of the plurality of first conductive layers.
10 more elements
A redistribution film for IC package, the redistribution film comprising:
- a bottom redistribution layer fabricated according to IC design rule, the bottom redistribution layer having a plurality of bottom metal pads and a plurality of first top metal pads, wherein a density of the plurality of bottom metal pads is higher than a density of the plurality of first top metal pads;
- a top redistribution layer fabricated according to PCB design rule, the top redistribution layer configured on top of the bottom redistribution layer and having a plurality of second top metal pads, wherein the density of the plurality of first top metal pads is higher than a density of the plurality of second top metal pads;
- a plurality of bumps configured on a top surface of the bottom redistribution layer;
- and
- a dielectric layer over the top surface of the bottom redistribution layer,
- wherein
- the plurality of first top metal pads of the bottom redistribution layer, bottom conductive features of the top redistribution layer, and the plurality of bumps are embedded in the dielectric layer,
- the bottom conductive features of the top redistribution layer are in direct electrical and physical contact with the corresponding first top metal pads of the bottom redistribution layer,
- top surfaces of the plurality of bumps are below a top surface of the dielectric layer,
- the bottom redistribution layer includes
- a plurality of first conductive layers, wherein a topmost first conductive layer among the plurality of first conductive layers includes the plurality of first top metal pads, and
- a plurality of first conductive vias coupling the plurality of first conductive layers to each other and to the plurality of bottom metal pads,
- the top redistribution layer includes
- a plurality of second conductive layers, wherein a topmost second conductive layer among the plurality of second conductive layers includes the plurality of second top metal pads, and
- a plurality of second conductive vias coupling the plurality of second conductive layers to each other and to the plurality of first top metal pads, and
- in a thickness direction in which the top redistribution layer is stacked on top of the bottom redistribution layer, the dielectric layer is (a) below the plurality of second conductive layers of the top redistribution layer and (b) above the plurality of first conductive vias of the bottom redistribution layer.
13 more elements
Dependencies are inferred from the claim text.