Polishing Pad with Secondary Window Seal

A polishing pad for a chemical mechanical polishing apparatus, comprising:

• a polishing article having a polishing surface and an aperture formed through the polishing article, the aperture including a first section adjacent the polishing surface and a second section adjacent the first section, wherein the polishing article includes a projection extending inwardly into the aperture such that the first section has a different lateral dimension from the second section, the projection having a first surface substantially parallel to the polishing surface, the polishing article including a lower portion on a side of the first surface farther from the polishing surface;
• a window having a first portion positioned in the first section of the aperture and a second portion extending into the second section of the aperture, the window having a second surface substantially parallel to the polishing surface;
• a first adhesive adhering the first surface of the projection to the second surface of the window to secure the window to the projection;
• and
• a second adhesive of different material composition than the first adhesive, the second adhesive positioned laterally between the second portion of the window and the lower portion of the polishing article.