**2. Dicing of wafer**

Wafer dicing is the process by which the individual unit of dies are separated from the wafer. This process may be carried out by using mechanical sawing, scribing, breaking or laser cutting. Of the several issues and challenges of RF MEMS packaging, dicing is one of the foremost challenges. In the case of ICs, the resultant contaminants or debris due to the dicing process, on the surface of the die can be easily removed by a post-dicing cleaning process, however, in the case of MEMS devices the fragile mechanical structures on the die may get damaged by these contaminants. Dicing methods such as mechanical sawing, scribing and breaking lead to debris from the dicing process which may scatter on to the die leading to buckling or breaking of the delicate MEMS structures. Therefore, the choice of the dicing process is of utmost importance in the case of RF MEMS devices.

In order to obtain least residues from the dicing process, Chicago Laser System (CLS 960) Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser has been employed. This is shown in **Figure 16**. Nd:YAG lasers are one of the most common types of laser used in cutting and welding steel, semiconductors and various alloys. These lasers typically emit light with a wavelength of 1064 nm, in the infrared.

**Figure 16.** *Chicago laser system (CLS 960) laser dicer.*

**Figure 17.** *Diced chips as seen under a microscope.*

## *Nanofibers - Synthesis, Properties and Applications*

The wafer to be diced was mounted on the dicing platform with the alignment set. The wafer is then diced into unit chips or dies with high precision. The unit dies obtained were observed under a microscope. It was visually confirmed that the RF MEMS switches were undamaged. The samples of diced chip are as shown in **Figure 17**.
