Multilayer polishing pads made by the methods for centrifugal casting of polymer polish pads

A system for manufacturing a multilayer chemical mechanical planarization pad using centrifugal casting, the system comprising:

• a plurality of polymer mixtures comprising at least a high density and a low density material wherein the polymer mixtures do not phase separate under ambient conditions;
• a multi-axis and multi-directional rotational centrifugal caster configured for multi-axis and multi-directional rotational centrifugal casting, the multi-axis and the multi-directional rotational centrifugal casting comprising rotating a cylindrical mold insert in a drum about a central axis and a second axis in a first direction and in a second direction respectively, the rotating the cylindrical mold insert in the drum about the central axis in the first direction being at a higher rotational velocity than the rotating the cylindrical mold insert in the drum about the second axis in the second direction;
• wherein the multi-axis and multi-directional rotational centrifugal caster comprises:
• a drum with an interior wall;
• and
• a mold insert with at least one outline of a chemical mechanical planaraization pad containing a window lining the interior wall of the drum, the mold insert adapted to confine the polymer mixture when the mold insert is rotating, the mold insert comprising channels for forming different types of chemical mechanical planarization pads and to improve slurry flow to ensure the presence of slurry on all areas of the multilayer chemical mechanical planarization pad;
• wherein the window enables optical endpoint technology;
• a dispenser exterior to the mold insert adapted to introduce the plurality of polymer mixtures into the mold insert;
• a pouring path that directs the plurality of polymer mixtures introduced by the dispenser exterior to the mold insert into an interior of the mold insert.

A method for making a multilayer chemical mechanical planarization pad using multi-axis and multi-directional rotational centrifugal casting, comprising:

• dispensing a polymer mixture comprising at least a polymer compound and a plurality of microspheres into a mold insert with at least one outline of a chemical mechanical planarization pad containing a window;
• sealing the mold insert such that the mold insert confines the polymer mixture;
• multi-axis and mufti-directional rotational centrifugal casting of the polymer mixture by rotating the mold insert about a plurality of axes segmenting the mold insert, the mufti-axis and the multi-directional rotational centrifugal casting comprising rotating the mold with the window about a central axis and a second axis in a first direction and in a second direction, the rotating the mold insert about the central axis in the first direction being at a higher rotational velocity than the rotating the mold insert about the second axis in the second direction;
• separating the polymer mixture under an influence of a centrifugal force of the multi-axis and the multi-directional rotational centrifugal casting into a solid, non-porous first layer comprising only the polymer compound and no microspheres and being free of voids or pores and being substantially uniform thickness and a second layer comprising the plurality of microspheres;
• forming a multilayer polymer sheet via gelling of the polymer mixture;
• removing the multilayer polymer sheet from the mold insert;
• and
• shaping a plurality of multilayer chemical mechanical planarization pads from the polymer sheet;
• wherein the window enables optical endpoint technology.