US Patent 7821346 Ovenized oscillator

An ovenized oscillator package including at least a heater and a crystal package mounted on opposite sides of a circuit board. Vias extend through the body of the circuit board to transfer heat from the heater to the crystal package. Layers of thermally conductive material extend through the body of the circuit board and are in thermally coupled relationship with the vias for spreading heat throughout the circuit board and other elements mounted thereon.