Patent ID: 7022990

Claim:
A hermetic infrared sensor package comprising: a base having a base wall and sidewalls surrounding the base wall to define a first recess within the base, the sidewalls defining a first hermetic sealing surface surrounding the first recess; a device chip within the first recess, the device chip having an infrared-sensing element thereon, the infrared-sensing element being located within the first recess at a depth below the first hermetic sealing surface and having a first depth dimension from the first hermetic sealing surface in a direction normal to the base wall; and a lid hermetically sealed with the base, the lid comprising an infrared-transmitting window and sidewalls surrounding the window, the window and the sidewalls cooperating to define a second recess in the lid, the sidewalls of the lid defining a second hermetic sealing surface surrounding the second recess and bonded to the first hermetic sealing surface of the base, the window having a second depth dimension from the second hermetic sealing surface in a direction normal to the base wall of the base, the second recess communicating with the first recess of the base to define a continuous cavity that is defined by and between the lid and the base and contains the device chip, the second depth dimension of the second recess of the lid being at least about half of the first depth dimension of the infrared-sensing element within the first recess, the sum of the first and second depth dimensions being a focal distance of the window to the infrared-sensing element.