Ablation method and recipe for wafer level underfill material patterning and removal

Patent metadata

Field	Value
Publication number	US-9786517-B2
Application number	US-201314021938-A
Country	US
Kind code	B2
Filing date	Sep 9, 2013
Priority date	Sep 9, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

Introducing an underfill material over contact pads on a surface of an integrated circuit substrate; and ablating the introduced underfill material to expose an area of the contact pads using temporally coherent electromagnetic radiation. A method including first ablating an underfill material to expose an area of contact pads on a substrate using temporally coherent electromagnetic radiation; introducing a solder to the exposed area of the contact pads; and second ablating the underfill material using temporally coherent electromagnetic radiation. A method including introducing an underfill material over contact pads on a surface of an integrated circuit substrate; defining an opening in the underfill material to expose an area of the contact pads using temporally coherent electromagnetic radiation; introducing a solder material to the exposed area of the contact pads; and after introducing the solder, removing the sacrificial material.

First claim

What is claimed is:

1. A method comprising:
introducing an underfill material over contact pads on a surface of an integrated circuit substrate, wherein the underfill material is selected from an epoxy material, a benzocyclobutene, a bismalleimide-type underfill material, a polybenzoxazine and a polynorbene; and
first ablating a portion of the underfill material to expose an area of the contact pads using temporally coherent electromagnetic radiation;
introducing a solder to the exposed area of the contact pads; and
after introducing the solder, second ablating a portion of the underfill material using temporally coherent electromagnetic radiation such that, following the second ablating, the underfill material on the surface of the integrated circuit substrate comprises a thickness of the contact pads,
wherein the second ablating includes ablating the underfill material selected from an epoxy material, a benzocyclobutene, a bismalleimide-type underfill material, a polybenzoxazine and a polynorbene.

2. The method of claim 1 , wherein after first ablating the underfill material to expose an area of the contact pads, exposing the contact pads to temporally coherent electromagnetic radiation.

3. The method of claim 1 , wherein first ablating comprises defining an opening in the underfill material to the contact pads.

4. The method of claim 1 , wherein the temporally coherent electromagnetic radiation is provided by a pulsed-wave ultraviolet laser.

5. The method of claim 1 , wherein prior to first ablating the underfill material, the underfill material is cured.

6. A method comprising:
introducing an underfill material over contact pads on a surface of an integrated circuit substrate, wherein the underfill material is selected from an epoxy material, a benzocyclobutene, a bismalleimide-type underfill material, a polybenzoxazine and a polynorbene;
first ablating the underfill material to expose an area of the contact pads using temporally coherent electromagnetic radiation;
introducing a solder to the exposed area of the contact pads; and
after introducing the solder, reducing a thickness of the underfill material on the surface of the integrated circuit substrate from a first thickness to a second thickness by second ablating the underfill material using temporally coherent electromagnetic radiation,
wherein the second ablating includes ablating the underfill material selected from an epoxy material, a benzocyclobutene, a bismalleimide-type underfill material, a polybenzoxazine and a polynorbene.

7. The method of claim 6 , wherein second ablating the underfill material comprises ablating the underfill material to a plane of the contact pads.

8. The method of claim 6 , wherein prior to introducing the solder, exposing the contact pads to temporally coherent electromagnetic radiation.

9. The method of claim 6 , wherein the temporally coherent electromagnetic radiation is provided by a pulsed-wave ultraviolet laser.

10. The method of claim 7 , wherein prior to first ablating the underfill material, curing the underfill material.

11. A method comprising:
introducing an underfill material over contact pads on a surface of an integrated circuit substrate, wherein the surface comprises a plurality of contact pads wherein introducing the underfill material comprises introducing the underfill material over the plurality of contact pads, wherein the underfill material is selected from an epoxy material, a benzocyclobutene, a bismalleimide-type underfill material, a polybenzoxazine and a polynorbene;
defining an opening in the underfill material to expose an area of the contact pads using temporally coherent electromagnetic radiation;
introducing a solder material to the exposed area of the contact pads; and
after introducing the solder material, reducing a thickness of the underfill material from a first thickness to a second thickness,
wherein reducing the thickness of the underfill material includes reducing a thickness of the underfill material selected from an epoxy material, a benzocyclobutene, a bismalleimide-type underfill material, a polybenzoxazine and a polynorbene.

12. The method of claim 11 , wherein reducing a thickness of the underfill material comprises ablating the underfill material to a thickness of the contact pads.

13. The method of claim 11 , wherein the temporally coherent electromagnetic radiation is provided by a pulsed-wave ultraviolet laser.

Assignees

• Dias Rajendra C
• Skoglund Lars D
• Indluru Anil R
• Prack Edward R
• Faruqui Danish
• Osborn Tyler N
• Eitan Amram
• Gosselin Timothy A
• Intel Corp

Inventors

• Dias Rajendra C
• Skoglund Lars D
• Indluru Anil R
• Prack Edward R
• Faruqui Danish
• Osborn Tyler N
• Eitan Amram
• Gosselin Timothy A

Classifications

• H10W72/0198

  batch processes · CPC title

• H10W72/952

  comprising metals or metalloids, e.g. PbSn, Ag or Cu · CPC title

• H10W72/9415

  relative to the surface, e.g. recessed, protruding · CPC title

• H10W72/29

  Bond pads specially adapted therefor · CPC title

• H10W72/019

  of bond pads · CPC title