The development of Cleaving — DBG + CMP process

Abstract

As telecommunication equipment that supports high-level information networks is being made portable, the requirements for telecommunication equipment to be small and lightweight are becoming stricter. Thus, miniaturization of semiconductor devices is necessary, and wafer dicing and chip thinning technologies are important key technologies to achieve it. Wafers are thinned by mechanical in-feed grinding using a grindstone containing diamond particles, and wafers are divided by mechanical blade dicing using a diamond blade. However, mechanical processes using diamond grits leave damage such as chipping, saw mark or residual strain on chip surfaces; thus, chip strength decreases. At chip thicknesses of 50 to 200 µm, such damage has to be avoided.In this study, novel manufacturing process steps for thin semiconductor devices are followed.

Die singulation technologies for advanced packaging: A critical review

“…[151][152][153][154][155][156][157] In an in-line DBG (Fig. 151,[158][159][160][161][162] Next, the wafer is mounted on a DAF tape, followed by removal of the device side surface protection tape. BSG starts with rough grinding at relatively high speed with coarse grinding means containing large sized diamond grains, followed by precision grinding at relatively low speed with fine grinding means containing small-sized diamond grains.…”

Evaluation by three-point-bend and ball-on-ring tests of thinning process on silicon die strength

“…Plasma etching after laser dicing improves significantly the die strength and the flexibility. Takyu et al [9] developed a novel manufacturing process for thin semiconductors devices based on DBG (dicing before grinding) and cleaving. With this process package could be very thin (thickness less than 20 lm).…”

Thin silicon wafer processing and strength characterization

“…The highest fracture strength is achieved by using either RIE or laser stealth dicing for the partial dicing step (Fig. 18) [44][45][46]. Note that laser ablation dicing generally results in lower fracture strength than diamond saw dicing, due to microcracks in the heat affected zone [40,42].…”

“…9) [5,28,32,37,38,40,[44][45][46]. In this process, full thickness wafers are partially diced from the frontside with either a conventional saw or by a plasma etch (with a resist mask), to a depth that is greater than the final wafer thickness.…”