A semiconductor package having an aperture in a die pad and solder in the aperture coplanar with a surface of the package is disclosed. The package includes a die pad, a plurality of leads, and a semiconductor die coupled to the die pad with a die attach material. A cavity or aperture is formed through the die pad to expose a portion of the die attach material. Multiple solder reflows are performed to reduce the presence of voids in the die attach material. In a first solder reflow, the voids of trapped gas that form when attaching the die to the die pad are released. Then, in a second solder reflow, solder is added to the aperture coplanar with a surface of the die pad. The additional solder can be the same material as the die attach material or a different material.

Development of smart objects with electronic functions requires integration of printed components with IC chips or dies. Conventional chip or die bonding including wire bonding, flip chip bonding, and soldering may not be applicable to chip or die attachment on low temperature plastic surfaces used in physical objects. Printing conductive connection traces requires a smooth interface between contact pads of a chip and the surface of the physical object. In order to address this issue of chip/die attachment to a physical object, this disclosure provides embodiments to construct a fixture on a chip or die for attachment and electrical connection onto a physical object by printing operations and/or ACF bonding methods.

A method for fabricating a three-dimensional (3D) electronic device. A liquid support material (e.g., an epoxy acrylate with a photoinitiator) is applied by a laser-induced forward transfer (LIFT) process to a printed circuit board (PCB) having one or more connectors and one or more electronic components thereon, and then cured to solid form by cooling and/or exposure to ultraviolet (UV) radiation. A layer of conductive material (e.g., a metal) is printed on the solidified support material by LIFT to electrically connect the one or more electronic components to respective ones of the connectors on the PCB. Subsequently, the layer of conductive material is dried by heating and metal particles in the conductive layer sintered using a laser beam. The assembly may then be encapsulated in an encapsulant.

An emissive panel and associated assembly method are provided. The method provides an emissive substrate having an insulating layer with a top surface and a back surface, and a dielectric layer overlying the insulating layer patterned to form a plurality of wells. Each well has a bottom surface formed on the insulating layer top surface with a first electrical interface electrically connected to a first conductive pressure channel (CPC). The CPCs are each made up of a pressure via with sidewalls formed between the well bottom surface and the insulating layer back surface. A metal layer coats the sidewalls, and a medium flow passage formed interior to the metal layer. The method uses negative pressure through the CPCs to help capture emissive elements in a liquid flow deposition process.

A programmable circuit includes an array of printed groups of microscopic transistors or diodes having pn junctions. The devices are pre-formed and printed as an ink and cured. The devices have a proper orientation and a reverse orientation after settling on a conductor layer. The devices are connected in parallel within small groups. To neutralize the reverse-oriented devices, a sufficient voltage is applied across the parallel-connected diodes to forward bias only the devices having the reverse orientation. This causes a sufficient current to flow through each of the reverse-orientated devices to destroy an electrical interface between an electrode of the devices and the conductor layer to create an open circuit, such that those devices do not affect a rectifying function of the devices in the group having the proper orientation. An interconnection conductor pattern may then interconnect the groups to form complex logic circuits.

A programmable circuit includes an array of printed groups of microscopic transistors or diodes having pn junctions. The devices are pre-formed and printed as an ink and cured. The devices have a proper orientation and a reverse orientation after settling on a conductor layer. The devices are connected in parallel within small groups. To neutralize the reverse-oriented devices, a sufficient voltage is applied across the parallel-connected diodes to forward bias only the devices having the reverse orientation. This causes a sufficient current to flow through each of the reverse-orientated devices to destroy an electrical interface between an electrode of the devices and the conductor layer to create an open circuit, such that those devices do not affect a rectifying function of the devices in the group having the proper orientation. An interconnection conductor pattern may then interconnect the groups to form complex logic circuits.

A method for fabricating a three-dimensional (3D) electronic device. A liquid support material (e.g., an epoxy acrylate with a photoinitiator) is applied by a laser-induced forward transfer (LIFT) process to a printed circuit board (PCB) having one or more connectors and one or more electronic components thereon, and then cured to solid form by cooling and/or exposure to ultraviolet (UV) radiation. A layer of conductive material (e.g., a metal) is printed on the solidified support material by LIFT to electrically connect the one or more electronic components to respective ones of the connectors on the PCB. Subsequently, the layer of conductive material is dried by heating and metal particles in the conductive layer sintered using a laser beam. The assembly may then be encapsulated in an encapsulant.

Electronic assembly methods and structures are described. In an embodiment, an electronic assembly method includes bringing together an electronic component and a routing substrate, and directing a large area photonic soldering light pulse toward the electronic component to bond the electronic component to the routing substrate.

Development of smart objects with electronic functions requires integration of printed components with IC chips or dies. Conventional chip or die bonding including wire bonding, flip chip bonding, and soldering may not be applicable to chip or die attachment on low temperature plastic surfaces used in physical objects. Printing conductive connection traces requires a smooth interface between contact pads of a chip and the surface of the physical object. In order to address this issue of chip/die attachment to a physical object, this disclosure provides embodiments to construct a fixture on a chip or die for attachment and electrical connection onto a physical object by printing operations and/or ACF bonding methods.

An integrated circuit is provided. The integrated circuit includes a package base including package leads, an extracted die removed from a previous packaged integrated circuit, and an an interposer bonded to the extracted die and the package base. The extracted die includes original bond pads and one or more original ball bonds on the original bond pads. The interposer includes first bond pads electrically connected to the original bond pads with 3D printed first bond connections conforming to the shapes and surfaces of the extracted die and the interposer and second bond pads electrically connected to the package leads with 3D printed second bond connections conforming to shapes and surfaces of the interposer and package base.