SMD Assembly Line | What is LED Flip Chip

LED flip chip means that the chip can be directly attached to the ceramic substrate without bonding wires. We call it a DA chip (Directly Attached chip).

The current flip chip is different from the early flip chip transfer to a silicon or other material substrate that still requires bonding wires; compared with the traditional front-mounted chip, the traditional chip electrical connection to the substrate through metal wire bonding Face up, while the electrical side of the flip chip is down, which is equivalent to turning over the traditional wafer.
ETA began to carry out flip chip packaging research in 2011, which is an expansion and extension based on the existing eutectic technology of our company.

Luminous characteristics of LED flip chip
In fact, flip-chips have a long history, juxtaposed with vertical structures and horizontal structures. Its luminous feature is that the active layer is facing down, and the transparent sapphire layer is located above the active layer. The light emitted by the active layer needs to pass through the sapphire liner Only then can it reach the outside of the chip.

Advantages of LED flip chip
1. No heat dissipation through sapphire, good heat dissipation performance Flip-chip structure, because the active layer is closer to the substrate, shortening the heat flow path from the heat source to the substrate, the flip-chip has a lower thermal resistance, this feature makes the flip chip from light to thermal stability, the performance decline is very large small.
2. In terms of luminous performance, the luminous efficiency is higher under high current drive. Flip chips have superior current spreading performance and ohmic contact performance. The voltage drop of flip structure chips is generally lower than that of traditional, vertical structure chips, which makes flip chips very advantageous under high current drive and shows higher light efficiency.
3. Under high power conditions, flip-chips are more secure and reliable than front-mounted chips. In LED devices, especially high-power, in the form of packaging with Lens (except the traditional anti-lumen structure with protective shell), more than half of the dead lights are related to the damage of the gold wire, and the flip chip can become a gold wire free Packaging, which reduces the probability of device dead lights from the source.

4. The size can be made smaller, reducing product maintenance costs, and the optical is easier to match; at the same time, it also lays the foundation for the development of subsequent packaging processes.

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