Flexible routing for chip on board applications

Patent metadata

Field	Value
Publication number	US-9287189-B2
Application number	US-201213713407-A
Country	US
Kind code	B2
Filing date	Dec 13, 2012
Priority date	Nov 7, 2012
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

Methods, systems, and apparatuses for semiconductor devices are provided herein. A semiconductor device includes an array of conductive pads for signals. One or more non-linear compliant springs may be present to route signals from the conductive pads to interconnect pads formed on the semiconductor device to attach bump interconnects. Each non-linear compliant spring may include one or more routing segments. The semiconductor device may be mounted to a circuit board by the bump interconnects. When the semiconductor device operates, heat may be generated by the semiconductor device, causing thermal expansion by the semiconductor device and the circuit board. The semiconductor device and circuit board may expand by different amounts due to differences in their thermal coefficients of expansion. The non-linear compliant springs provide for compliance between the conductive pads and bump interconnects to allow for the different rates of expansion.

First claim

What is claimed is:

1. A semiconductor device, comprising:
a silicon die having an electrically conductive die pad;
at least one routing segment configured as a non-linear compliant spring in at least one routing layer formed on the silicon die, the at least one routing segment being electrically conductive, wherein the non-linear compliant spring comprises a first routing segment and a second routing segment, and wherein the first and second routing segments intersect at a joint and form an acute angle; and
an electrically conductive interconnect pad formed at a surface layer of the semiconductor device, the interconnect pad configured to mount an interconnect member, the at least one routing segment coupled between the die pad and interconnect pad, and the non-linear compliant spring configured to at least enable compliance to facilitate positional displacement of the interconnect pad relative to the die pad.

2. The semiconductor device of claim 1 , wherein the non-linear compliant spring is configured to enable compliance along an axis parallel to a plane of a routing layer formed on the silicon die.

3. The semiconductor device of claim 1 , wherein the non-linear compliant spring is configured to enable compliance along an axis orthogonal to a plane of a routing layer formed on the silicon die.

4. The semiconductor device of claim 1 , wherein the first and second routing segments are in a same routing layer formed on the silicon die.

5. The semiconductor device of claim 1 , wherein the first and second routing segments are in different routing layers formed on the silicon die.

6. The semiconductor device of claim 1 , wherein the non-linear compliant spring further comprises:
at least one additional routing segment that intersects with at least one other routing segment of the non-linear compliant spring at an additional joint to form an additional acute angle.

7. The semiconductor device of claim 1 , wherein the non-linear compliant spring comprises:
a curved routing segment.

8. A method for forming a semiconductor device, comprising:
forming a first electrically insulating layer on a surface of an integrated circuit (IC) region, the IC region including at least one conductive pad;
forming at least one routing segment configured as a non-linear compliant spring in at least one routing layer within the first electrically insulating layer, the at least one routing segment being electrically conductive and being coupled to the conductive pad through an opening in the first electrically insulating layer;
forming a second electrically insulating layer over the at least one routing segment; and
coupling an interconnect member to the at least one routing segment through an opening in the second electrically insulating layer.

9. The method of claim 8 , wherein said forming at least one routing segment configured as a non-linear compliant spring in at least one routing layer within the first electrically insulating layer comprises:
forming a first routing segment; and
forming a second routing segment connected to the first routing segment by a first joint;

wherein the first routing segment and second routing segment form an acute angle.

10. The method of claim 8 , wherein said forming at least one routing segment configured as a non-linear compliant spring in at least one routing layer within the first electrically insulating layer comprises:
forming a first routing segment and a second routing segment in the at least one routing layer on the first electrically insulating layer, the first and second routing segments being coupled together at a first joint, and the first routing segment being connected to the conductive pad through the opening.

11. The method of claim 8 , wherein said forming at least one routing segment configured as a non-linear compliant spring in at least one routing layer within the first electrically insulating layer comprises:
forming a first routing segment in a first routing layer within the first electrically insulating layer, the first routing segment being connected to the conductive pad through the opening;
forming an intermediate electrically insulating layer on the first routing layer; and
forming a second routing segment in a second routing layer on the intermediate electrically insulating layer, the second routing segment being electrically coupled to the first routing segment through an opening in the intermediate electrically insulating layer at a first joint.

12. The method of claim 8 , wherein said forming at least one routing segment configured as a non-linear compliant spring in at least one routing layer within the first electrically insulating layer comprises:
forming a curved routing segment within the first electrically insulating layer.

13. The method of claim 8 , wherein said forming at least one routing segment configured as a non-linear compliant spring comprises:
configuring the non-linear compliant spring to have a compliant region where stiffness is substantially constant with spring deformation.

14. An integrated circuit (IC) package, comprising:
an IC die having a plurality of electrically conductive die pads on a first surface of the IC die;
at least one electrically insulating layer formed on the first surface of the IC die;
a plurality of routing segments configured as non-linear compliant springs in at least one routing layer within the at least one electrically insulating layer, the plurality of routing segments being electrically conductive;
a plurality of first electrically conductive interconnect pads on a surface of the at least one electrically insulating layer, each of the respective plurality of routing segments coupled between a respective die pad of the plurality of die pads and a respective first electrically conductive interconnect pad of the plurality of interconnect pads, and each non-linear compliant spring configured to at least enable compliance to facilitate positional displacement of the respective electrically conductive interconnect pad relative to the respective die pad; and
a plurality of electrically conductive interconnect members, each respective electrically conductive interconnect member attached to a respective electrically conductive interconnect pad on the surface of the at least one electrically insulating layer, including a respective electrically conductive interconnect member attached to a respective electrically conductive interconnect pad.

15. The IC package of claim 14 , wherein the plurality of non-linear compliant springs are configured to enable compliance along an axis parallel to a plane of a routing layer within the at least one electrically insulating layer.

16. The IC package of claim 15 , wherein the plurality of non-linear compliant springs further comprise:
a centrally located first set of non-linear compliant springs configured to have a first stiffness; and
a peripherally located second set of non-linear compliant springs configured to have a second stiffness, the first stiffness being greater than the second stiffness.

17. The IC package of claim 15 , wherein the plurality of non-linear compliant springs further comprise:
a centrally located first set of non-linear compliant springs configured to have a first compliance region corresponding to a first spring deformation region;
an intermediately located second set of non-linear compliant springs configured to have a second compliance region corresponding to a second spring deformation region, the second spring deformation region being wider than the first spring deformation region; and

Assignees

• Broadcom Corp

Inventors

• Bhagavat Milind S
• Sandhu Javed Iqbal
• Khan Rezaur Rahman
• Tan Teck Yang

Classifications

• H10W72/29

  Bond pads specially adapted therefor · CPC title

• H10W72/9415

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

• H10W72/9223

  with redistribution layers [RDL] · CPC title

• H10W72/923

  Bond pads having multiple stacked layers · CPC title

• H10W72/01938

  in gaseous form, e.g. by CVD or PVD · CPC title