초록 ▼

A method for packaging and protection of sensors, particularly so called microsensors is disclosed. A sensor unit (either a sensor chip or sensor package) is flip chip bonded to a substrate having a through hole, such that the sensing element is placed above the through hole. An underfill material i

A method for packaging and protection of sensors, particularly so called microsensors is disclosed. A sensor unit (either a sensor chip or sensor package) is flip chip bonded to a substrate having a through hole, such that the sensing element is placed above the through hole. An underfill material is applied in such a way that due to capillary forces, the entire common area between the sensor and the substrate is completely filled, while the sensing element is not covered by the underfill material. This provides an effective way of sealing the sensing element from the side of the package containing the electronics. For a sensor chip that has been through a first level packaging process, the above mentioned method can still be used for bonding the sensor package to a substrate containing an access hole. For some applications one or multiple layers of protective coatings can be deposited on either one side or both sides of the sensor package for protection against the operating environment. For applications where the sensor is required to operate in a controlled pressure/controlled gas environment, a cavity can be created into the substrate, and the sensor chip can be flip chip bonded (and/or sealed) to the substrate in a controlled environment. An alternative method of packaging is disclosed where the sensor chip is fixed onto the substrate, and a cap is bonded to this substrate using dummy bumps for mechanical strength.

대표청구항 ▼

[ We claim:] [1.] A method of packaging a sensor unit having an active face which includes a sensor element on the active face of said sensor unit, said method comprising the steps of:providing a substrate having a rear surface, a front surface, and electrical connection means on said rear surface;f

[ We claim:] [1.] A method of packaging a sensor unit having an active face which includes a sensor element on the active face of said sensor unit, said method comprising the steps of:providing a substrate having a rear surface, a front surface, and electrical connection means on said rear surface;forming a cavity in said substrate;locating said sensor unit over said substrate, with said active face facing in the direction of said rear surface of said substrate, and said sensor element over said cavity;electrically connecting said sensor unit to said electrical connection means;securing said sensor unit to said substrate;dispensing an underfill material at an interface between said sensor unit and said substrate;due to capillary force on said underfill material, drawing said underfill material between said interface such that said underfill material fills at least a portion of said interface between said sensor unit and said substrate without covering said sensor element; andforming a seal at said interface between said sensor unit and said substrate, said seal completely circumscribing said sensor element and isolating said sensor element and said cavity from said rear surface of said substrate.