Electrochemical additive manufacturing system having conductive seed layer

Patent metadata

Field	Value
Publication number	US-2024162049-A1
Application number	US-202318533008-A
Country	US
Kind code	A1
Filing date	Dec 7, 2023
Priority date	Aug 23, 2019
Publication date	May 16, 2024
Grant date	—

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

1 - 20 . (canceled)

21 . An electrochemical additive manufacturing system, comprising:
a reaction chamber configured to retain an ionic solution that can be decomposed by electrolysis; an anode array disposed in the reaction chamber and configured to be immersed in the ionic solution; a substrate disposed in the reaction chamber, wherein the substrate comprises a plate and a conductive seed layer on the plate where the conductive seed layer defines a surface of the substrate and is configured to be in contact with the ionic solution; a mechanical positioning system configured to modify one or more of a position and orientation of one or more of the anode array and the substrate; and a microcontroller programmed to:
transmit control signals to the mechanical positioning system to modify the relative position and orientation of the anode array and the substrate so that:
the anode array and the substrate are substantially coplanar; and
the anode array is aligned with a predetermined position of one or more features of the substrate;

accept a three-dimensional model of features to be added to the substrate; and
based on the three-dimensional model of features, control the current through each anode of the anode array to construct the features on the surface of the substrate at the predetermined position.

22 . The system of claim 21 , further comprising one or more attachments that are configured to hold a position of the substrate and to provide an electrical connection to the conductive seed layer.

23 . The system of claim 22 , wherein the one or more attachments comprises at least one clamp that clamps down on the substrate.

24 . The system of claim 23 , wherein a portion of the at least one clamp is in contact with the conductive seed layer and ground of a power supply circuit of the system that supplies the current through the anode array.

25 . The system of claim 23 , wherein:
the one or more attachments comprises two clamps; a first clamp of the two clamps clamps a first side of the substrate; a second clamp of the two clamps clamps a second side of the substrate that is opposite the first side of the substrate; a portion of the first clamp is in contact with the conductive seed layer and ground of a power supply circuit of the system that supplies the current through the anode array; and a portion of the second clamp is in contact with the conductive seed layer and ground of the power supply circuit of the system.

26 . The system of claim 21 , wherein:
the substrate comprises two or more tiles; and the microcontroller is further programmed to:
transmit a first set of control signals to the mechanical positioning system to align the anode array with a first tile of the two or more tiles;
control the current through each anode of the anode array to construct the features on the first tile;
transmit a second set of control signals to the mechanical positioning system to align the anode array with a second tile of the two or more tiles; and
control the current through each anode of the anode array to construct the features on the second tile.

27 . The system of claim 21 , wherein the conductive seed layer comprises multiple sub-layers.

28 . The system of claim 27 , wherein at least one of the multiple sub-layers of the conductive seed layer is made from a material that is different than at least another one of the multiple sub-layers of the conductive seed layer.

29 . The system of claim 28 , wherein the at least one of the multiple sub-layers of the conductive seed layer is made from a first metallic material and the at least another one of the multiple sub-layers of the conductive seed layer is made from a second metallic material.

30 . The system of claim 27 , wherein:
the multiple sub-layers comprise a first sub-layer deposited directly onto the plate and a second sub-layer deposited onto the first sub-layer; and the first sub-layer is thicker than the second sub-layer.

31 . The system of claim 27 , wherein:
the multiple sub-layers comprise a first sub-layer deposited directly onto the plate and a second sub-layer deposited onto the first sub-layer; the first sub-layer is a physical vapor deposition deposited layer; and the second sub-layer is an electrodeposition deposited layer.

32 . The system of claim 27 , wherein a thickness of the conductive seed layer varies across the plate.

33 . The system of claim 32 , wherein:
the conductive seed layer comprises a first sub-layer deposited directly onto the plate and a second sub-layer deposited onto the first sub-layer; the first sub-layer has a constant thickness; and the second sub-layer is an electrodeposition deposited layer and has a variable thickness.

34 . The system of claim 21 , further comprising an electrically non-conductive layer, made of an electrically non-conductive material, disposed on at least some of the conductive seed layer of the substrate such that the non-conductive layer is interposed between the conductive seed layer and the ionic solution.

35 . The system of claim 34 , wherein the microcontroller is further programmed to successively activate selected anodes of the anode array to deposit a metallic material onto the electrically non-conductive material so that the metallic material is in contact with at least one of the features constructed on the surface of the substrate.

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