<Process Example>
What kind of components are been used in mobile phones? Many components such as LSI, SAW filters, LED, COMS sensors can be cited. In recent years, with the rapid miniaturization of mobile phones, the demand for these components to be smaller and thinner has increased.
Lithium Tantalite (hereafter called “LT”) is used as a material for SAW filters. Disco currently provides many applications related to LT; however the following explains the DBG process as one application to solve the processing problems facing LT.
The topic “Grinding Lithium Tantalite” was presented previously in April 28, 2006. As the final grinding thickness is made thinner, the wafer warpage tends to become bigger, as shown in the graph below. In addition, this is due to a characteristic of the LT material and as a result of this wafer warpage, breakage occurs easily.
Accordingly, by applying the “DBG process merit: Reduction of wafer breakage rate” (presented in August 10, 2005) to the LT process, it is possible to prevent wafer breakage. Furthermore, while also using the DBG merit of eliminating die side cracking, which was explained in “Reduction of backside chipping” (presented in August 10, 2005), it is possible to grind to the required roughness depending on the grinding wheel and settings of the process conditions.
The ability to currently have a mobile phone with an internal camera, which is small enough to go into a shirt pocket, is because all the components can be made smaller and thinner. By providing thinning technology for LT, which is a difficult material to cut, Disco is playing a part in miniaturizing mobile phones.
Note: The warpage amount, which is indicated in this graph, is for a 4-inch wafer. It has been ground on the backside and measured, without half-cut.
