Patent ID: 8276460

Claim:
A chip-on-board pressure sensor apparatus, comprising: a chip-on-board substrate defined by a first major surface and an opposing second major surface, the chip-on-board substrate having a through-hole extending from the first major surface of the chip-on-board substrate through to the second major surface of the chip-on-board substrate; a pressure transducer, the pressure transducer having: a pressure transducer die with a pressure transducer element; a constraint defined by a first major surface and an opposing second major surface with a side wall extending between the first major surface and the second major surface, wherein the side wall of the constraint defines a perimeter of the constraint, the constraint further having a through-hole that extends from the first major surface through to the second major surface of the constraint; the pressure transducer die bonded to the first major surface of the constraint, with the pressure transducer element of the pressure transducer die in registration with the through-hole of the constraint; a ceramic buffer defined by a first major surface and an opposing second major surface with a side wall extending between the first major surface and the second major surface, wherein the side wall of the ceramic buffer defines a perimeter of the ceramic buffer, the ceramic buffer further having a through-hole that extends from the first major surface through to the second major surface of the ceramic buffer; the ceramic buffer interposed between and bonded to the constraint of the pressure transducer and the chip-on-board substrate, with the through-hole of the ceramic buffer in fluid communication with the through-hole of the constraint, wherein the perimeter of the ceramic buffer extends out beyond the perimeter of the constraint, and the ceramic buffer is bonded to the chip-on-board substrate in the portion of the ceramic buffer that extends out beyond the perimeter of the constraint; and wherein said ceramic buffer includes a coefficient of thermal expansion that is between that of said constraint and said chip-on-board substrate.