A fingerprint sensor device and a method of making a fingerprint sensor device. As non-limiting examples, various aspects of this disclosure provide various fingerprint sensor devices, and methods of manufacturing thereof, that comprise a sensing area on a bottom side of a die without top side electrodes that senses fingerprints from the top side, and/or that comprise a sensor die directly electrically connected to conductive elements of a plate through which fingerprints are sensed.

An integrated circuit structure includes a substrate, a metal pad over the substrate, a passivation layer having a portion over the metal pad, and a polymer layer over the passivation layer. A Post-Passivation Interconnect (PPI) has a portion over the polymer layer, wherein the PPI is electrically coupled to the metal pad. The integrated circuit structure further includes a first solder region over and electrically coupled to a portion of the PPI, a second solder region neighboring the first solder region, a first coating material on a surface of the first solder region, and a second coating material on a surface of the second solder region. The first coating material and the second coating material encircle the first solder region and the second solder region, respectively. The first coating material is spaced apart from the second coating material.

An integrated circuit structure includes a substrate, a metal pad over the substrate, a passivation layer having a portion over the metal pad, and a polymer layer over the passivation layer. A Post-Passivation Interconnect (PPI) has a portion over the polymer layer, wherein the PPI is electrically coupled to the metal pad. The integrated circuit structure further includes a first solder region over and electrically coupled to a portion of the PPI, a second solder region neighboring the first solder region, a first coating material on a surface of the first solder region, and a second coating material on a surface of the second solder region. The first coating material and the second coating material encircle the first solder region and the second solder region, respectively. The first coating material is spaced apart from the second coating material.

A mounting structure includes a first substrate that has a first surface on which a functional element is provided, a wiring that is provided at a position which is different from a position of the functional element on the first surface, and is connected to the functional element, a second substrate that has a second surface facing the first surface, and a conductor that is provided on the second surface, and is connected to the wiring and the functional element, in which the shortest distance between the functional element and the second substrate is longer than a distance between a position where the wiring is connected to the conductor, and the second substrate.

A fingerprint sensor device and a method of making a fingerprint sensor device. As non-limiting examples, various aspects of this disclosure provide various fingerprint sensor devices, and methods of manufacturing thereof, that comprise a sensing area on a bottom side of a die without top side electrodes that senses fingerprints from the top side, and/or that comprise a sensor die directly electrically connected to conductive elements of a plate through which fingerprints are sensed.

A fingerprint sensor device and a method of making a fingerprint sensor device. As non-limiting examples, various aspects of this disclosure provide various fingerprint sensor devices, and methods of manufacturing thereof, that comprise a sensing area on a bottom side of a die without top side electrodes that senses fingerprints from the top side, and/or that comprise a sensor die directly electrically connected to conductive elements of a plate through which fingerprints are sensed.

An integrated circuit structure includes a substrate, a metal pad over the substrate, a passivation layer having a portion over the metal pad, and a polymer layer over the passivation layer. A Post-Passivation Interconnect (PPI) has a portion over the polymer layer, wherein the PPI is electrically coupled to the metal pad. The integrated circuit structure further includes a first solder region over and electrically coupled to a portion of the PPI, a second solder region neighboring the first solder region, a first coating material on a surface of the first solder region, and a second coating material on a surface of the second solder region. The first coating material and the second coating material encircle the first solder region and the second solder region, respectively. The first coating material is spaced apart from the second coating material.

An integrated circuit structure includes a substrate, a metal pad over the substrate, a passivation layer having a portion over the metal pad, and a polymer layer over the passivation layer. A Post-Passivation Interconnect (PPI) has a portion over the polymer layer, wherein the PPI is electrically coupled to the metal pad. The integrated circuit structure further includes a first solder region over and electrically coupled to a portion of the PPI, a second solder region neighboring the first solder region, a first coating material on a surface of the first solder region, and a second coating material on a surface of the second solder region. The first coating material and the second coating material encircle the first solder region and the second solder region, respectively. The first coating material is spaced apart from the second coating material.

A flux formulation includes an activator and a protic solvent. The activator may be glutaric acid, levulinic acid, 2-ketobutyric acid, 2-oxovaleric acid, or mixtures thereof. Suitable protic solvents include alkanediol, alkoxy propanol and alkoxy ethanol. The flux formulation may be a no-clean flux formulation that may be used in the soldering of electronic circuit board assemblies, for example, in conjunction with a support fixture having a planar back surface that minimizes vibrations during processing that might otherwise cause misalignment between a chip and a substrate prior to solder reflow.

A flux formulation includes an activator and a protic solvent. The activator may be glutaric acid, levulinic acid, 2-ketobutyric acid, 2-oxovaleric acid, or mixtures thereof. Suitable protic solvents include alkanediol, alkoxy propanol and alkoxy ethanol. The flux formulation may be a no-clean flux formulation that may be used in the soldering of electronic circuit board assemblies, for example, in conjunction with a support fixture having a planar back surface that minimizes vibrations during processing that might otherwise cause misalignment between a chip and a substrate prior to solder reflow.