If you’ve ever heard of blade dicing, you’ve probably wondered about plasma scribing and stealth dicing. These four methods are based on different principles. Depending on the type of semiconductor and the type of circuit board, dicing can be done either directly on the circuit board or by packaging dice into sanitary packages. The width of the streets, or the squares or rectangles that are left on the tape, can vary from 0.1 to 35 mm. While there are many variables that affect dicing, careful attention is required to control cracking and contamination. Precision control of several variables is essential for ensuring a more accurate process.
Blade dicing
A dicing blade is an indispensable tool for cutting and shaping a wide variety of materials, from thick-film devices to glass-on-silicon. Depending on the type of material, a dicing blade can be used for both scribing and custom shaping. A variety of parameters must be considered, including blade thickness, feed rate, spindle speed, and exposure. These factors will determine how much material is exposed to the blade.
The cutting force, or force required to cut a silicon wafer, varies depending on the size of the semiconductor wafer. For example, a dicing blade with a metal nozzle will require higher dicing forces, while a resin-bonded one will experience more radial wear. In addition, a surface morphology study revealed that the chips tended to be chipped and show obvious brittle fracture characteristics. Chipping fracture modes were cleavage and intergranular mixed cracking. During the cutting process, the blade makes ten passes, and each pass causes the SiC wafer to vibrate.
Plasma dicing
There are two main methods for dicing American semiconductor wafers, laser dicing and plasma dipping. Both methods require a high concentration of photon streams to create localized high temperatures. Laser dicing removes the area near the dicing lane. Plasma dipping involves focusing the heat into the wafer bulk. The high temperature of the laser creates voids within the dicing lane, acting like perforations. These weakened regions tear apart when the wafer expands.
Both UTAC plasma dicing and dipping are suitable for bumped solder balls and non-bumped wafers. The benefits of plasma dicing include no degradation of ball shear strength and no issues with exposed AlCu pads. Both techniques offer a high level of pass reliability, ranging from THS 85C/85%RH at 1000 hours. The webcast is designed to educate dicing professionals on the benefits of plasma dicing.
Stealth dicing
Japanese researchers have invented a new dicing process known as stealth dicing for ultrathin American semiconductor wafers. This new technology has been used to make chips with low-k dielectric constants and specialty materials, including MEMS. It could soon be used for sapphire as well. Stealth dicing reduces water consumption by up to six-hundred tons a year.
For this study, four-inch diameter silicon carbide (4H-SiC) wafers of 200 mm were chosen for the simulation. The main principle of this dicing process is to minimize chipping and cracks while achieving a smooth cutting track. The results of this simulation differ slightly, as different laser parameters produce different results. In the case of dicing a wafer, the method results in less edge breakage and a higher production rate than conventional dicing methods.
This stealth dicing method creates rows of perforations in the SD layer. Unlike laser ablation, stealth dicing is different because the laser beam does not create a “Heat Affect Zone” that damages the sensitive electronic circuitry on a wafer. While this process is more costly than laser ablation, it is still a viable alternative for cutting American semiconductor wafers.
Scribing
One of the most common problems associated with scribing American semiconductor wafers is irregularity of the scribe point geometry. Since the scribe point geometry varies depending on wafer thickness and contour, it is difficult to predict the optimum static load prior to scribing. Additionally, the scribe point geometry is prone to deformation, which complicates its use. As a result, scribing is difficult in such cases because of irregular wafer contours, which make it more challenging to prevent chip damage. In addition to this, a damaged wafer can damage active semiconductor regions.
The scribe assembly and video camera are installed in the same area of the machine. The camera lens is positioned between the scribe module and the anvil break mechanism. This arrangement helps reduce the travel of the table in the X direction, while the operator can monitor the scribe point during the scribing process. In addition, the video camera identifies the precise point of the wafer and generates a cross-hair on the video screen.
