# US 7,411,297 B2 · Microfeature devices and methods for manufacturing microfeature devices

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- Number: US 7,411,297 B2
- Document ID: US7411297B2
- Status: Granted
- Kind: B2
- Application number: 11/407,435
- Filed: 2006-04-20
- Published: 2006-08-24
- Granted: 2008-08-12
- Earliest claimed: 2004-06-14
- Assignees: Micron Technology, Inc.
- Inventors: Shijian Luo; Tongbi Jiang
- Web page: https://patentgrep.com/patent/US7411297B2

## CPC

- H10W 72/20: Bump connectors, e.g. solder bumps or copper pillars; Dummy bumps; Thermal bumps
- H10W 74/012: {of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills}
- H10W 74/014: {using batch processing}
- H10W 74/15: on active surfaces of flip-chip devices, e.g. underfills
- H10W 72/242: {relative to the surface, e.g. recessed, protruding}
- H10W 72/251: {Materials}
- H10W 72/856: {Bump connectors and die-attach connectors (bumps embedded in underfills H10W74/15)}
- H10W 72/90: Bond pads, in general
- H10W 72/9415: {relative to the surface, e.g. recessed, protruding}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Microfeature devices, microfeature workpieces, and methods for manufacturing microfeature devices and microfeature workpieces are disclosed herein. The microfeature workpieces have an integrated circuit, a surface, and a plurality of interconnect elements projecting from the surface and arranged in arrays on the surface. In one embodiment, a method includes forming a coating on the interconnect elements of the microfeature workpiece, producing a layer over the surface of the microfeature workpiece after forming the coating, and removing the coating from at least a portion of the individual interconnect elements. The coating has a surface tension less than a surface tension of the interconnect elements to reduce the extent to which the material in the layer wicks up the interconnect elements and produces a fillet at the base of the individual interconnect elements.

## Claims

### Claim 1

A microfeature device, comprising:
a microelectronic die having an integrated circuit and a plurality of bond-pads electrically coupled to the integrated circuit;
a plurality of conductive interconnect elements projecting from the die and electrically coupled to corresponding bond-pads;
a sacrificial coating on at least a portion of the individual interconnect elements, wherein the sacrificial coating has a first surface tension and the interconnect elements have a second surface tension greater than the first surface tension; and
a layer over the die and proximate to the interconnect elements.

### Claim 2 (depends on 1)

The microfeature device of claim 1 wherein the layer comprises a protective layer.

### Claim 3 (depends on 1)

The microfeature device of claim 1 wherein the layer comprises an underfill layer.

### Claim 4 (depends on 1)

The microfeature device of claim 1 wherein the layer comprises an underfill layer, and wherein the underfill does not cover the interconnect elements.

### Claim 5 (depends on 1)

The microfeature device of claim 1 wherein the layer comprises an underfill layer including filler elements.

### Claim 6 (depends on 1)

The microfeature device of claim 1 wherein the sacrificial coating comprises Silane.

### Claim 7 (depends on 1)

The microfeature device of claim 1 wherein the layer has a third surface tension greater than the first surface tension of the sacrificial coating.

### Claim 8 (depends on 1)

The microfeature device of claim 1 wherein the sacrificial coating covers the die proximate to the interconnect elements and the layer covers a portion of the sacrificial coating.

### Claim 9 (depends on 1)

The microfeature device of claim 1 wherein the sacrificial coating encases the individual interconnect elements.

### Claim 10 (depends on 1)

The microfeature device of claim 1 wherein:
the individual interconnect elements include a proximal portion and a distal portion; and
the sacrificial coating covers the proximal portion and not the distal portion of the individual interconnect elements.

### Claim 11 (depends on 1)

The microfeature device of claim 1 wherein the sacrificial coating inhibits the layer from wicking up the interconnect elements.

### Claim 12

A microfeature workpiece, comprising:
a plurality of microelectronic devices having a surface;
a plurality of conductive balls arranged in discrete arrays on the surface and electrically coupled to corresponding microelectronic devices;
a sacrificial film covering the individual conductive balls, the sacrificial film having a first surface tension and the conductive balls having a second surface tension greater than the first surface tension; and
a layer over the surface of the microelectronic devices.

### Claim 13 (depends on 12)

The microfeature workpiece of claim 12 wherein the layer comprises a protective layer over the surface.

### Claim 14 (depends on 12)

The microfeature workpiece of claim 12 wherein the layer comprises an underfill layer over the surface.

### Claim 15 (depends on 12)

The microfeature workpiece of claim 12 wherein the layer comprises an underfill layer over the surface, and wherein the underfill does not cover the conductive balls.

### Claim 16 (depends on 12)

The microfeature workpiece of claim 12 wherein the layer comprises an underfill layer including filler elements.

### Claim 17 (depends on 12)

The microfeature workpiece of claim 12 wherein the sacrificial film comprises Silane.

### Claim 18 (depends on 12)

The microfeature workpiece of claim 12 wherein the layer has a third surface tension greater than the first surface tension of the sacrificial film.

### Claim 19

A microfeature workpiece, comprising:
a plurality of microelectronic devices having a surface;
a plurality of conductive interconnect elements projecting from the surface and electrically coupled to corresponding microelectronic devices, the individual conductive interconnect elements including a proximal portion and a distal portion opposite the proximal portion;
a sacrificial film covering the proximal portion and not the distal portion of the individual conductive interconnect elements, the sacrificial film having a first surface tension and the conductive interconnect elements having a second surface tension greater than the first surface tension; and
a layer over the surface of the microelectronic devices.

### Claim 20 (depends on 19)

The microfeature workpiece of claim 19 wherein the layer comprises a protective layer.

### Claim 21 (depends on 19)

The microfeature workpiece of claim 19 wherein the layer has a third surface tension greater than the first surface tension of the sacrificial film.