LED is the abbreviation of Light Emitting Diode (LED). It is a solid-state cold light source that uses semiconductors as luminescent materials. When a forward voltage is applied to both ends, the carriers in the semiconductor recombine, release energy, and emit photons. , Produces visible light. LED lamps have a life of up to 10,000 hours, and their luminous efficiency is ten times that of incandescent lamps and twice that of fluorescent lamps. At the same time, it is anti-vibration, safe, not easy to break, and environmentally friendly. It is the fourth generation of new energy after incandescent lamps, fluorescent lamps, high-intensity high-pressure sodium lamps and metal halide lamps. Its unique light-emitting method has become a typical energy-saving and environmentally friendly Green light source.
LEDs are small in size, light in weight, low in price, long in life, and environmentally friendly. They are widely used in backlighting, road traffic, transportation, and display screens. With the advancement of LED chip technology, the expansion of the market and the increase of people's requirements, LED cutting technology is constantly improving. In the early days due to technical limitations, the cutting of non-metal substrate materials (mainly sapphire) during LED production was mainly diamond dicing, but the sapphire material was too hard, and the diamond wear was relatively large, and it was diced. The latter material will cause a certain degree of physical deformation, produce fine cracks, and then affect the performance of the device.
The second generation of diamond grinding wheel blade sawing is by embedding tiny diamond particles around a nickel wheel blade of a certain size and thickness. When cutting, the grinding wheel blade will cut along the cutting path through high-speed rotation, so as to realize the cutting of the LED wafer. With the vigorous development of GaN-based sapphire substrate LEDs that conform to the times and the continuous development and innovation of laser pointer technology, the third generation of cutting methods has emerged, that is, laser scribing technology. The current mainstream laser scribing technology mainly uses laser "thermal cutting", that is, by guiding and focusing the laser beam, the focus of the beam is focused to the position of the cutting material.
The focused laser beam can release a large amount of energy in a very short time, melt or even vaporize the material at the site, and at the same time use the movement of the laser device's galvanometer to form cutting marks, thereby achieving the purpose of wafer cutting. Although the "thermal cutting" technology using lasers can have huge advantages in cutting speed and cutting quality, with the development of LED applications, the market has more stringent requirements for LED production. Laser "hot cutting" due to the existence of a large amount of slag on the cutting surface and edge chipping during cutting, so people began to turn laser scribing technology to "cold cutting" based on ultrashort pulse lasers.
In order to solve some of the remaining problems of the laser scribing "thermal cutting" technology, scientific researchers continue to make technical explorations. The green laser pointer invisible cutting technology invented by Hamamatsu Co., Ltd. solves the defects of laser scribing cutting technology to a certain extent. The working principle of the laser stealth cutting technology is to use an ultra-short pulse laser beam with a wavelength that can pass through the semiconductor chip. After being focused, it passes through the surface of the cutting material, and the beam is focused on a point inside the material, and then the beam follows the set Cutting line scan. Compared with the previous laser scribing technology, the laser stealth cutting technology belongs to a dry processing method, so there will be no defects caused by the wet processing process, and it can reduce the working time required during production.