Electrochemical additive manufacturing method using deposition feedback control

Patent metadata

Field	Value
Publication number	US-11881412-B2
Application number	US-202217982338-A
Country	US
Kind code	B2
Filing date	Nov 7, 2022
Priority date	Aug 23, 2019
Publication date	Jan 23, 2024
Grant date	Jan 23, 2024

Abstract

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 μm or more, diameters of 10 μm or below, and inter-pillar spacing below 20 μm. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

First claim

What is claimed is:

1. An electrochemical additive manufacturing method, comprising steps of:
placing a surface of a semiconductor die, having electrical connection pads, into an electrolyte solution, wherein an object to be manufactured is constructed by electrochemically depositing material onto the electrical connection pads of the semiconductor die;
placing an anode array in contact with the electrolyte solution, wherein:
the anode array comprises a plurality of deposition anodes; and
each of the plurality of deposition anodes is configured to provide current that flows therefrom to the electrical connection pads of the semiconductor die through the electrolyte solution, resulting in deposition of the material onto the electrical connection pads of the semiconductor; and

manufacturing the object by transmitting control signals to the anode array so that the material deposited onto the electrical connection pads forms columns that initiate on respective ones of the electrical connection pads at locations that are spaced apart along a surface of the semiconductor die by a first distance, and that are angled at a slant, relative to the surface of the semiconductor die and away from each other, so that connection points, defined by terminal ends of the columns, are spaced apart, in a direction parallel to the surface of the semiconductor die, by a second distance that is greater than the first distance.

2. The electrochemical additive manufacturing method according to claim 1 , wherein each one of the columns comprises a first portion, which is angled at a first angle relative to the surface of the semiconductor die, and a second portion, which is angled at a second angle relative to the surface of the semiconductor die, wherein the second angle is different than the first angle and a non-orthogonal angle is defined between the first portion and the second portion of each one of the columns.

3. The electrochemical additive manufacturing method according to claim 2 , wherein the second angle is an orthogonal angle and the first angle is an oblique angle.

4. The electrochemical additive manufacturing method according to claim 2 , wherein the non-orthogonal angle defined between the first portion and the second portion is an obtuse angle.

5. The electrochemical additive manufacturing method according to claim 4 , wherein:
each one of the columns comprises a bend; and
the first portion of each one of the columns is connected to the second portion of the corresponding one of the columns by the bend.

6. The electrochemical additive manufacturing method according to claim 2 , wherein an entire length of the first portion of each one of the columns is more than an entire length of the second portion of the corresponding one of the columns.

7. The electrochemical additive manufacturing method according to claim 2 wherein the second portion of each one of the columns extends directly from the a corresponding one of the electrical connection pads of the surface of the semiconductor die.

8. The electrochemical additive manufacturing method according to claim 2 , wherein the first portions of the columns comprise the terminal ends.

9. The electrochemical additive manufacturing method according to claim 2 , wherein manufacturing the object further comprises forming additional columns so that at least two of the columns are angled relative to the surface of the semiconductor die in the same general direction, wherein a minimum distance between the second portions of the at least two of the columns is more than a minimum distance between the first portions of the at least two of the plurality of interconnection features.

10. The electrochemical additive manufacturing method according to claim 9 , wherein
a first offset, in a direction parallel to the surface of the semiconductor die, between the second portion of a first one of the at least two columns the second portion of a second one of the at least two columns is greater than a second offset, in the direction parallel to the surface of the semiconductor die, between the connection point of the first one of the at least two columns and the connection point of the second one of the at least two columns.

11. The electrochemical additive manufacturing method according to claim 9 , wherein the first angle of a first one of the at least two columns is different than the first angle of a second one of the at least two columns.

12. The electrochemical additive manufacturing method according to claim 9 , wherein:
a non-orthogonal angle is defined between the first portion and the second portion of each one of the at least two columns; and
the non-orthogonal angle defined between the first portion and the second portion of a first one of the at least two columns is different than the non-orthogonal angle defined between the first portion and the second portion of a second one of the at least two columns.

13. The electrochemical additive manufacturing method according to claim 9 , wherein:
an entire length of the first portion of a first one of the at least two columns is different than an entire length of the first portion of a second one of the at least two columns; and
an entire length of the second portion of the first one of the at least two columns is different than the entire length of the second portion of the second one of the at least two columns.

14. The electrochemical additive manufacturing method according to claim 13 , wherein:
the first one of the at least two columns is adjacent to the second one of the at least two columns; and
the entire length of the first portion of the first one of the at least two columns is greater than the entire length of the first portion of the second one of the at least two columns; and
the entire length of the second portion of the first one of the at least two columns is greater than the entire length of the second portion of the second one of the at least two columns.

15. The electrochemical additive manufacturing method according to claim 14 , wherein the second angle is an orthogonal angle.

16. The electrochemical additive manufacturing method according to claim 14 , wherein:
in a first direction, parallel to the surface of the semiconductor die, from a point on the surface of the semiconductor die, the first one of the at least two columns is before the second one of the at least two columns;
in a second direction, parallel to the surface of the semiconductor die and opposite the first direction, from the point on the surface of the semiconductor die, a third one of the at least two columns is before a fourth one of the at least two columns;
the entire length of the first portion of the third one of the at least two columns is greater than the entire length of the first portion of the fourth one of the at least two columns; and
the entire length of the second portion of the third one of the at least two columns is greater than the entire length of the second portion of the fourth one of the at least two columns.

17. The electrochemical additive manufacturing method according to claim 2 , further comprising depositing an inert material onto the semiconductor die between the first portions of the columns, after the first portions of the columns are formed and before the second portions of the columns are formed.

18. The electrochemical additive manufacturing method according to claim 1 , wherein:
a seed layer is on top of the semiconductor die;
the material is deposited onto regions of the seed layer; and
the electrochemical additive manufacturing method fu

Assignees

• Fabric8Labs Inc

Inventors

• Pain David
• Edmonds Andrew
• Herman Jeffrey
• Pateros Charles
• Shaik Kareemullah

Classifications

• H10W70/041

  Connecting or disconnecting interconnections to or from leadframes, e.g. connecting bond wires or bumps · CPC title

• H10W40/037

  Assembling together parts thereof · CPC title

• H10W72/0198

  batch processes · CPC title

• H10W72/237

  Multiple bump connectors having different shapes · CPC title

• H10W72/247

  Dispositions of multiple bumps · CPC title