Provided among other things is an electrical device comprising: a first component that is a semiconductor or an electrical conductor; a second component that is an electrical conductor; and a strong, heat stable junction there between including an intermetallic bond formed of: substantially (a) indium (In), tin (Sn) or a mixture thereof, and (b) substantially nickel (Ni). The junction can have an electrical contact resistance that is small compared to the resistance of the electrical device.

Provided among other things is an electrical device comprising: a first component that is a semiconductor or an electrical conductor; a second component that is an electrical conductor; and a strong, heat stable junction there between including an intermetallic bond formed of: substantially (a) indium (In), tin (Sn) or a mixture thereof, and (b) substantially nickel (Ni). The junction can have an electrical contact resistance that is small compared to the resistance of the electrical device.

MicroLED devices can be transferred in large numbers to form microLED displays using processes such as pick-and-place, thermal adhesion transfer, or fluidic transfer. A blanket solder layer can be applied to connect the bond pads of the microLED devices to the terminal pads of a support substrate. After heating, the solder layer can connect the bond pads with the terminal pads in vicinity of each other. The heated solder layer can correct misalignments of the microLED devices due to the transfer process.

A mount structure includes two members that are bonded to each other with a bonding material layer having a first interface layer and a second interface layer at the interfaces with the two members. The bonding material layer contains a first intermetallic compound and a stress relaxation material. The first intermetallic compound has a spherical, a columnar, or an oval spherical shape, and the same crystalline structure as the first interface layer and the second interface layer, and partly closes the space between the first interface layer and the second interface layer. The stress relaxation material contains tin as a main component, and fills around the first intermetallic compound.

Disclosed is a die-bonding method which provides a target substrate having a circuit structure with multiple electrical contacts and multiple semiconductor elements each semiconductor element having a pair of electrodes, arranges the multiple semiconductor elements on the target substrate with the pair of electrodes of each semiconductor element aligned with two corresponding electrical contacts of the target substrate, and applies at least one energy beam to join and electrically connect the at least one pair of electrodes of every at least one of the multiple semiconductor elements and the corresponding electrical contacts aligned therewith in a heating cycle by heat carried by the at least one energy beam in the heating cycle. The die-bonding method delivers scattering heated dots over the target substrate to avoid warpage of PCB and ensures high bonding strength between the semiconductor elements and the circuit structure of the target substrate.

A method of forming a chip assembly may include forming a plurality of cavities in a carrier; The method may further include arranging a die attach liquid in each of the cavities; arranging a plurality of chips on the die attach liquid, each chip comprising a rear side metallization and a rear side interconnect material disposed over the rear side metallization, wherein the rear side interconnect material faces the carrier; evaporating the die attach liquid; and after the evaporating the die attach liquid, fixing the plurality of chips to the carrier.

Methods and apparatus are disclosed for attaching the integrated circuit (IC) packages to printed circuit boards (PCBs) to form smooth solder joints. A polymer flux may be provided in the process to mount an IC package to a PCB. The polymer flux may be provided on connectors of the IC package, or provided on PCB contact pad and/or pre-solder of the PCB. When the IC package is mounted onto the PCB, the polymer flux may cover a part of the connector, and may extend to cover a surface of the molding compound on the IC package. The polymer flux may completely cover the connector as well. The polymer flux delivers a fluxing component that facilitates smooth solder joint formation as well as a polymer component that offers added device protection by encapsulating individual connectors. The polymer component may be an epoxy.

In an aspect, a system and method for assembling a semiconductor device on a receiving surface of a destination substrate is disclosed. In another aspect, a system and method for assembling a semiconductor device on a destination substrate with topographic features is disclosed. In another aspect, a gravity-assisted separation system and method for printing semiconductor device is disclosed. In another aspect, various features of a transfer device for printing semiconductor devices are disclosed. In yet another aspect, a method and structure for heat-assisted micro-transfer printing is disclosed.

A power electronic package includes a first substrate, a second substrate oppositely disposed from the first substrate, one or more chips disposed between the substrates, and at least three spacers. The spacers control a height variation of the power electronic package and protect the chips and other electronics from experiencing excessive stress. The height of the spacers is determined based on a height of the chips, on a height of solder blocks that connect the chips to the top substrate, and on a height of solder blocks that connect the chips to the bottom substrate.

Methods and apparatus are disclosed for attaching the integrated circuit (IC) packages to printed circuit boards (PCBs) to form smooth solder joints. A polymer flux may be provided in the process to mount an IC package to a PCB. The polymer flux may be provided on connectors of the IC package, or provided on PCB contact pad and/or pre-solder of the PCB. When the IC package is mounted onto the PCB, the polymer flux may cover a part of the connector, and may extend to cover a surface of the molding compound on the IC package. The polymer flux may completely cover the connector as well. The polymer flux delivers a fluxing component that facilitates smooth solder joint formation as well as a polymer component that offers added device protection by encapsulating individual connectors. The polymer component may be an epoxy.