Tiltable platform for additive manufacturing of a polishing pad

Patent metadata

Field	Value
Publication number	US-2018079152-A1
Application number	US-201715494302-A
Country	US
Kind code	A1
Filing date	Apr 21, 2017
Priority date	Sep 20, 2016
Publication date	Mar 22, 2018
Grant date	—

Abstract

An additive manufacturing apparatus for forming a polishing pad for chemical mechanical polishing includes a platform, an actuator system coupled to the platform to adjust a tilt of the platform, one or more printheads supported above the platform, the one or more printheads configured to dispense successive layers of feed material on the platform to be form the polishing pad, a sensing system to detect a height of a surface on or above the platform at each of a plurality of horizontally spaced points, and a controller configured to selectively operate the actuator system to adjust the tilt of the platform based on the detected height of the platform at each of the points such that the surface is moved closer to horizontal.

First claim

What is claimed is:

1 . An additive manufacturing apparatus comprising:
a platform; an actuator system coupled to the platform to adjust a tilt of the platform; one or more printheads supported above the platform, the one or more printheads configured to dispense successive layers of feed material on the platform, the layers of feed material to be formed into a polishing pad; a sensing system to detect a height of a surface on or above the platform at each of a plurality of horizontally spaced points; and a controller configured to selectively operate the actuator system to adjust the tilt of the platform based on the detected height of the platform at each of the points such that the surface is moved closer to horizontal.

2 . The apparatus of claim 1 , wherein:
the surface corresponds to a top surface of the layers of feed material, the sensing system is configured to detect a height of the top surface of the layers of feed material on the platform at each of the points, and the controller is configured to selectively operate the actuator system to adjust the tilt of the platform based on the detected height of the top surface of the layers of feed material at each of the points.

3 . The apparatus of claim 1 , wherein the surface corresponds to a top surface of the platform, and the controller is configured to selectively operate the actuator system before the one or more printheads dispense the layers of feed material.

4 . The apparatus of claim 1 , comprising a support arranged above the platform, wherein the one or more printheads are mounted to the support above the platform, and an actuator coupled to the support.

5 . The apparatus of claim 4 , wherein the controller is configured to selectively operate the actuator to vertically move the support based on the detected height of the surface at each of the points.

6 . The apparatus of claim 4 , wherein the sensing system is mounted on the support.

7 . The apparatus of claim 1 , wherein the sensing system comprises a non-contact sensor to detect the height of the surface at each of the points.

8 . The apparatus of claim 7 , wherein the sensing system comprises an optical sensor to detect the height of the layers of feed material at each of the points.

9 . The apparatus of claim 1 , wherein the controller is configured to determine a height skew based on the height of the surface at each of the points, and selectively operate the actuator system to pivot the platform so as to reduce the height skew.

10 . The apparatus of claim 9 , wherein the controller is further configured to operate the actuators to lower the platform after each of the layers of feed material is deposited so as to maintain a constant height offset between the one or more printheads and an exposed layer of the layers of the feed material from layer-to-layer.

11 . The additive manufacturing apparatus of claim 1 , wherein at least some of the points are positioned proximate to where a perimeter of the polishing pad is to be formed.

12 . The additive manufacturing apparatus of claim 11 , wherein the at least some of the points are positioned at equal angular intervals around a vertical axis through a center of where the polishing pad is to be formed.

13 . The additive manufacturing apparatus of claim 12 , wherein the points positioned at equal angular intervals around the vertical axis comprise four points.

14 . The additive manufacturing apparatus of claim 12 , wherein at least one of the points is positioned along a vertical axis through a center of where the polishing pad is to be formed.

15 . The additive manufacturing apparatus of claim 1 , wherein the actuator system comprises a plurality of vertical actuators positioned at different angular positions around a center of the platform.

16 . The additive manufacturing apparatus of claim 15 , wherein the platform is pivotally coupled to the each of the plurality of vertical actuators.

17 . The additive manufacturing apparatus of claim 15 , wherein the actuator system comprises three vertical actuators.

18 . The apparatus of claim 1 , wherein the controller is configured to adjust a dispensing operation of a second printhead in response to detecting an error condition associated with the first printhead while operating the printheads to successively dispense the layers of feed material.

19 . A method comprising:
detecting a height of a surface on or above a platform at each of a plurality of horizontally spaced points; adjusting a tilt of the platform based on the detected height of the surface at each of the points such that the surface on the platform is moved closer to horizontal; and successively dispensing a plurality of layers of feed material on the platform from one or more printheads, the layers of feed material to be formed into a polishing pad.

20 . The method of claim 19 , wherein detecting the height of the surface comprises detecting a height of a top surface of the layers of feed material at each of the points, and adjusting the tilt of the platform comprises adjusting the tilt of the platform based on the detected height of the top surface of the plurality of layers of feed material at each of the points.

21 . The method of claim 20 , comprising adjusting the tilt of the platform after depositing each layer of the plurality of layers of feed material.

22 . The method of claim 19 , wherein detecting the height of the surface comprises detecting a height of a top surface of the platform at each of the points, and adjusting the tilt of the platform comprises adjusting the tilt of the platform before successively dispensing the plurality of layers of feed material.

Assignees

• Applied Materials Inc

Inventors

• Ng Hou T
• Patibandla Nag B
• Ganapathiappan Sivapackia

Classifications

• G01N2015/1493

  Particle size · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B24B37/245

  Pads with fixed abrasives · CPC title

• B29L2031/736

  Grinding or polishing equipment · CPC title

• B24B37/26

  characterised by the shape of the lapping pad surface, e.g. grooved · CPC title