How are wafers cut?

With the development of the microelectronics industry, traditional electronic packaging technology can no longer fully meet the requirements, because this packaging technology is complex in design, high in cost, and limits the performance and reliability of ICs. The effect of the silicon wafer cutting process directly affects the performance and benefits of the chip.

The chip dicing method is different from the typical IC dicing method. Conventional IC grinding wheel dicing is to complete the cutting of materials by rotating the grinding wheel blade at high speed, thereby achieving cutting. Because the blade rotates at high speed, pure water is often needed for cooling and rinsing. Therefore, the pressure and torque generated by the high-speed rotation of the blade, the impact force generated by the pure water rinsing, and the contamination of debris and gaps can easily cause irreversible damage to the mechanical microstructure of the MEMS chip. Therefore, general IC grinding wheel dicing is not suitable for MEMS wafer dicing.

Laser cutting technology emerged in this situation, and it is widely used in MEMS wafers, RFID wafers and Memory wafers.

As a solution for laser cutting wafers, laser cutting avoids the problems in grinding wheel cutting. Optical shaping is performed using a single pulse pulse laser to focus the material surface on the inside of the material, thereby increasing the energy density in the focused area, thereby forming a nonlinear absorption effect of multi-photon absorption, so that the material is modified to produce cracks. Each laser pulse acts at an equal distance, and the formation of equal distance damage can form a modified layer in the material. The molecular bonds of the materials in the changed layer are destroyed, and the connection between the materials becomes fragile and easy to separate. After cutting, the product is completely separated by stretching the carrier film, and a gap is created between the chips. This treatment method avoids damage caused by direct mechanical contact and pure water flushing.

Laisai laser cutting technology can be used for compounds such as sapphire/glass/silicon and many semiconductor wafers.