In flip chip assembly, the chips are mounted to a substrate, board, or carrier by flipping them over so that the top side faces down and the pads align with the corresponding pads on the external circuit; solder is then flowed to complete the interconnect. This is in contrast to wire bonding where the chip is mounted upright and wires are used to interconnect the chip pads with the external circuitry.
The advantage of the flip chip process is that the need for wire bonding is eliminated (direct chip attach) and therefore can support a final application much smaller than their counterparts.
Flip chip processes have gained popularity among manufacturers of cell phones and other small electronics where the size savings are valuable without compromising performance.
Palomar Technologies Solution
Assembly Services has supported precision direct-chip attach (DCA) LED bonding for several years. The DCA process helps minimize design space by eliminating the need for wire bonds. With both anode and cathode terminations on the bottom side of the LED, controlling the amount of flux becomes even more important.
You cannot have any bridging between the anode and cathode. Assembly Services has perfected the precision and repeatability of the DCA process, allowing Palomar Technologies to support designs with high numbers of LEDs per part.
The 3800 Die Bonder is a flexible, computer-controlled die bonder and automated component placement system that performs flip chip operations over a large work area. It also contains a look-up camera with flip chip vision processing.
|3800 Die Bonder