Embodiments relate to using flux or underfill as a trapping layer for temporarily attaching light emitting diodes (LEDs) to a substrate and heating to simultaneously bond multiple LEDs onto the substrate. The flux or underfill may be selectively coated at the ends of electrodes of the LEDs prior to placing the LEDs on the substrate. Due to adhesive properties of the flux or underfill, multiple LEDs can be placed on and attached to the substrate prior to performing the bonding process. Once LEDs are placed on the substrate, the flux or underfill facilitates formation of metallic contacts between electrodes of the LED and contacts of the substrate during the bonding process. By using the flux or underfill, the formation of metallic contacts can be performed even without applying pressure.

A method includes placing a coupling mechanism material layer on a backside of a wafer having power devices fabricated on a frontside thereof, and placing conductive spacer blocks on the coupling mechanism material layer on a backside of the selected wafer. The method further includes activating the coupling mechanism material to bond the conductive spacer blocks to the backside of the selected wafer, and singulating the wafer to separate the vertical device stacks, each of the singulated vertical device stacks including a device die bonded to, or fused with, a conductive spacer block.

A method includes placing a coupling mechanism material layer on a backside of a wafer having power devices fabricated on a frontside thereof, and placing conductive spacer blocks on the coupling mechanism material layer on a backside of the selected wafer. The method further includes activating the coupling mechanism material to bond the conductive spacer blocks to the backside of the selected wafer, and singulating the wafer to separate the vertical device stacks, each of the singulated vertical device stacks including a device die bonded to, or fused with, a conductive spacer block.

A uniform pressure gang bonding device and fabrication method are presented using an expandable upper chamber with an elastic surface. Typically, the elastic surface is an elastomer material having a Young's modulus in a range of 40 to 1000 kilo-Pascal (kPA). After depositing a plurality of components overlying a substrate top surface, the substrate is positioned over the lower plate, with the top surface underlying and adjacent (in close proximity) to the elastic surface. The method creates a positive upper chamber medium pressure differential in the expandable upper chamber, causing the elastic surface to deform. For example, the positive upper chamber medium pressure differential may be in the range of 0.05 atmospheres (atm) and 10 atm. Typically, the elastic surface deforms between 0.5 millimeters (mm) and 20 mm, in response to the positive upper chamber medium pressure differential.

Embodiments relate to using flux or underfill as a trapping layer for temporarily attaching light emitting diodes (LEDs) to a substrate and heating to simultaneously bond multiple LEDs onto the substrate. The flux or underfill may be selectively coated at the ends of electrodes of the LEDs prior to placing the LEDs on the substrate. Due to adhesive properties of the flux or underfill, multiple LEDs can be placed on and attached to the substrate prior to performing the bonding process. Once LEDs are placed on the substrate, the flux or underfill facilitates formation of metallic contacts between electrodes of the LED and contacts of the substrate during the bonding process. By using the flux or underfill, the formation of metallic contacts can be performed even without applying pressure.

A composite is produced by providing a first and a second joining partner, a connecting means, a sealing means, a reactor having a pressure chamber, and a heating element. The two joining partners and the connecting means are arranged in the pressure chamber such that the connecting means is situated between the first joining partner and the second joining partner. A gas-tight region is then produced, in which the connecting means is arranged. Afterward, a gas pressure of at least 20 bar is produced in the pressure chamber outside the gas-tight region. The gas pressure acts on the gas-tight region and presses the first joining partner, the second joining partner and the connecting means together. The joining partners and the connecting means are then heated by means of the heating element to a predefined maximum temperature of at least 210 C. and then cooled.

An apparatus and a method for chip-to-wafer integration is provided. The apparatus includes a coating module, a bonding module and a cleaning module. The method includes the steps of placing at least one chip on a wafer to form an integrated product, forming a film on the integrated product, such that the integrated product is substantially fluid-tight, and exerting a predetermined positive pressure on the film during permanent bonding of the at least one chip to the wafer. The method further includes the step of removing the film from the integrated product after permanent bonding of the at least one chip to the wafer.