# US 8,786,059 B2 · Passivation layer surface topography modifications for improved integrity in packaged assemblies

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- Number: US 8,786,059 B2
- Document ID: US8786059B2
- Status: Granted
- Kind: B2
- Application number: 13/468,223
- Filed: 2012-05-10
- Published: 2012-09-13
- Granted: 2014-07-22
- Earliest claimed: 2009-11-25
- Assignees: International Business Machines Corporation
- Applicants: Alexandre Blander; Jon A Casey; Timothy H Daubenspeck; Ian D Melville; Jennifer V Muncy; Marie-Claude Paquet
- Inventors: Alexandre Blander; Jon A Casey; Timothy H Daubenspeck; Ian D Melville; Jennifer V Muncy; Marie-Claude Paquet
- Web page: https://patentgrep.com/patent/US8786059B2

## CPC

- H10W 74/473: {containing a filler}
- H10W 74/127: {characterised by arrangements for sealing or adhesion}
- H10W 74/012: {of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills}
- H10W 74/15: on active surfaces of flip-chip devices, e.g. underfills
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A structure and method for producing the same is disclosed. The structure includes an organic passivation layer with solids suspended therein. Preferential etch to remove a portion of the organic material and expose portions of such solids creates enhanced surface roughness, which provides a significant advantage with respect to adhesion of that passivation layer to the packaging underfill material.

## Claims

### Claim 1

A structure comprising:
a passivation layer over a base structure, said passivation layer comprising an organic polymer material and an adhesion promoter having a silicon-containing end; and
a plurality of particles in said passivation layer comprising moisture bonded to said silicon-containing end of said adhesion promoter, wherein at least some of said plurality of particles are on a surface of said passivation layer and separated by a gap not containing said organic polymer material so that said surface of said passivation layer is a roughened surface.

### Claim 2 (depends on 1)

The structure according to claim 1, further comprising:
an encapsulation layer bonded to said roughened surface of said passivation layer.

### Claim 3 (depends on 1)

The structure according to claim 1, wherein said organic polymer material is polyimide, and said adhesion promoter comprises an aminosilane-like compound.

### Claim 4 (depends on 2)

The structure according to claim 2, further comprising:
a package assembly bonded to said encapsulation layer, and
wherein said base structure is an integrated circuit assembly comprising a device layer and a metallization layer, such that said device layer is in electrical contact with a portion of said package assembly.

### Claim 5 (depends on 1)

The structure according to claim 1 wherein said particles have an average diameter between about 0.01 and 0.3 micron.

### Claim 6 (depends on 1)

The structure according to claim 1 wherein a height variation of said roughened surface of said passivation layer is in the range of about 0.01 micron to 1.0 micron.

### Claim 7 (depends on 3)

The structure according to claim 3 wherein said aminosilane-like compound is an aminosilane.

### Claim 8 (depends on 1)

The structure according to claim 1, wherein the roughened surface of said passivation layer comprises a smooth field portion and a micromask area.

### Claim 9 (depends on 8)

The structure according to claim 8, wherein the micromask area comprises a bump or a spike.

### Claim 10 (depends on 4)

The structure according to claim 4 further comprising:
a contact structure to enable electrical connection of said metallization layer to said package assembly.

### Claim 11 (depends on 10)

The structure according to claim 10 wherein said contact structure is adjacent to said encapsulation layer.

### Claim 12 (depends on 10)

The structure according to claim 10 wherein said contact structure is a solder ball.

### Claim 13 (depends on 1)

The structure of claim 1 further comprising a hard dielectric layer adjacent said passivation layer.

### Claim 14 (depends on 1)

The structure of claim 1 further comprising a density of said particles in said passivation layer wherein said density is about 10 particles per micron cubed.

### Claim 15 (depends on 1)

The structure of claim 1, wherein said particles comprise about 5 percent of said passivation layer.

### Claim 16 (depends on 1)

The structure of claim 1, where said moisture bonded to said silicon-containing end of said adhesion promoter is a hydrolysis product.

### Claim 17 (depends on 16)

The structure of claim 16, where said hydrolysis product is selected from the group consisting of H and OH.