Semiconductor device packages and methods of forming the same
Semiconductor device packages and methods of forming the same are discussed. In an embodiment, a device includes: a redistribution structure comprising an upper dielectric layer and an under-bump metallization; a buffer feature on the under-bump metallization and the upper dielectric layer, the buffer feature covering an edge of the under-bump metallization, the buffer feature bonded to the upper dielectric layer; a reflowable connector extending through the buffer feature, the reflowable connector coupled to the under-bump metallization; an interposer coupled to the reflowable connector; and an encapsulant around the interposer and the reflowable connector, the encapsulant different from the buffer feature.
1 . A method comprising:
forming a redistribution structure on a carrier substrate;
forming dangling bonds on an upper dielectric layer of the redistribution structure by treating the upper dielectric layer;
forming a buffer layer on the upper dielectric layer and on an under-bump metallization of the redistribution structure by bonding a buffer material to the dangling bonds;
patterning the buffer layer with a first opening exposing the under-bump metallization;
connecting an interposer to the under-bump metallization with a first conductive connector, the first conductive connector disposed in the first opening;
encapsulating the interposer and the first conductive connector;
after encapsulating the interposer and the first conductive connector, exposing a lower dielectric layer of the redistribution structure by removing the carrier substrate;
patterning the lower dielectric layer with a second opening exposing a metallization pattern of the redistribution structure; and
connecting a semiconductor device to the metallization pattern with a second conductive connector, the second conductive connector disposed in the second opening.
2 . The method of claim 1 , wherein the dangling bonds are hydroxyl groups and treating the upper dielectric layer comprises performing a plasma treatment process with O 2 , N 2 , H 2 , or a combination thereof.
3 . The method of claim 1 , wherein the buffer material is a photosensitive polymer and patterning the buffer layer comprises exposing the buffer layer to light and developing the buffer layer.
4 . The method of claim 1 , wherein the buffer material is a molding compound and patterning the buffer layer comprises drilling the buffer layer.
5 . The method of claim 1 , wherein the upper dielectric layer has a first thickness, the buffer layer has a second thickness, and the second thickness is greater than the first thickness.
6 . The method of claim 1 , wherein the upper dielectric layer is disposed on a middle dielectric layer of the redistribution structure, a first bonding strength between the upper dielectric layer and the middle dielectric layer being less than a second bonding strength between the upper dielectric layer and the buffer layer.
7 . The method of claim 1 , wherein the buffer layer completely covers the upper dielectric layer after the patterning the buffer layer.
8 . The method of claim 1 , wherein patterning the buffer layer exposes a portion of the upper dielectric layer.
9 . A method comprising:
forming a redistribution structure on a carrier substrate;
forming a buffer layer on an upper dielectric layer and under-bump metallizations of the redistribution structure;
patterning the buffer layer to expose the under-bump metallizations;
connecting an interposer to the under-bump metallizations, the interposer having a first coefficient of thermal expansion;
removing the carrier substrate to expose a lower dielectric layer of the redistribution structure;
patterning the lower dielectric layer to expose a metallization pattern of the redistribution structure; and
connecting a semiconductor device to the metallization pattern, the semiconductor device having a second coefficient of thermal expansion, the second coefficient of thermal expansion less than the first coefficient of thermal expansion.
10 . The method of claim 9 , wherein the interposer comprises an organic substrate.
11 . The method of claim 9 , wherein the upper dielectric layer comprises a photosensitive polymer and the lower dielectric layer comprises a photoinsensitive polymer.
12 . The method of claim 9 , wherein the buffer layer comprises the same material as the upper dielectric layer.
13 . The method of claim 9 , wherein the buffer layer comprises a different material from the upper dielectric layer.
14 . A method comprising:
forming a redistribution structure on a carrier substrate, the redistribution structure including an outer insulating layer;
forming an under-bump metallization on a first side of the redistribution structure, the under-bump metallization extending through the outer insulating layer;
forming a buffer layer over the first side of the redistribution structure and the under-bump metallization, wherein the outer insulating layer is disposed on a middle dielectric layer of the redistribution structure, a first bonding strength between the outer insulating layer and the middle dielectric layer being less than a second bonding strength between the outer insulating layer and the buffer layer;
curing the buffer layer, wherein the buffer layer bonds to the outer insulating layer using covalent bonds;
patterning the buffer layer to expose a surface of the under-bump metallization, the buffer layer remaining along sidewalls of the under-bump metallization;
attaching an interposer to the under-bump metallization using a first conductive connector, the interposer having a first coefficient of thermal expansion (CTE); and
attaching a semiconductor device to a second side of the redistribution structure, the semiconductor device having a second CTE different than the first CTE.
15 . The method of claim 14 , wherein the buffer layer has a Young's modulus in a range of 0.05 GPa to 30 GPa.
16 . The method of claim 14 , wherein patterning the buffer layer comprises patterning a ring around the under-bump metallization.
17 . The method of claim 14 , wherein the redistribution structure includes an outer insulating layer, wherein the under-bump metallization extends through the outer insulating layer, wherein the buffer layer completely covers the outer insulating layer after patterning the buffer layer.
18 . The method of claim 14 , wherein the buffer layer comprises a resin with fillers disposed therein.
19 . The method of claim 14 , further comprising:
prior to forming the buffer layer, performing a treatment process on the outer insulating layer to create dangling bonds.
20 . The method of claim 1 , further comprising:
curing the buffer layer, wherein after curing the buffer layer is bonded to the upper dielectric layer with covalent bonds.