Wafer Level
A global light-emitting diode (LED) specialist, Seoul Semiconductor launched a new Wafer Level Integrated Chip on PCB (Wicop) product, Wicop 2, at the Shanghai Pudong Marriott Hotel in China on Sept. 5. The new product is free from die bonding and wire bonding processes for conventional LED package manufacturing and components such as lead frames and gold wires.
At the moment, a majority of LEDs require die bonding that attaches chips on lead frames, wire bonding equipment that connects electrodes with gold wires, and components such as lead frames and gold wires for each process.
An LED produced through this process is limited in how small it can be, since the size of its chip is larger than that of its package. But Wicop is a completely new LED product that overcomes the limitations of chip scale packages (CSPs). Seoul Semiconductor developed Wicop and began mass production of the product in 2012.
The product does not need a separate packaging step since it connects a chip and a PCB directly. It does not have an intermediate substrate, which makes the sizes of the chip and the package the same, either. It is very tiny, demonstrates high efficiency, and boasts high thermal conductivity and optical density.
Chip Scale Package (CSP) technology based on silicon semiconductors can decrease the sizes of semiconductor components into those of chips. A foreign company launched a new product by applying this technology to LEDs. In 2013, domestic companies also began to develop this technology.
But the previous products cannot be called perfect CSPs, since die-bonding equipment for attaching chips on PCBs and intermediate substrates based on ceramic or silicon materials were used in making them. But Seoul Semiconductor mass produced perfect Wicop products with same-sized packages and chips, and without other materials, by directly putting chips on PCBs, and supplied them to corporate customers.