The single-electrode chip has very high requirements on the die bonding in the packaging industry. For example, in the LED production process, the quality of the die bonding affects the quality of the LED finished product. There are many factors that cause LED solid crystal cracking. We only discuss the solutions to LED solid crystal cracking from three aspects of materials, machinery and man-made factors.
The chip material itself is cracked
When the chip is damaged more than 1/5 of the width of a single chip or the chip is at an oblique angle, each chip with a length of more than 2/5 or damaged to an aluminum pad is not acceptable. . The main reasons for the bad phenomenon are: 1. Improper operation of the chip manufacturer; 2. The chip incoming inspection has not been spot checked; 3. The online operation has not been selected.
Solution: 1. Notify the LED chip manufacturer to improve it; 2 Strengthen the incoming inspection and reject the chips with too many broken ratios; 3. During the online inspection of the Q, the damaged chips should be singled out and replaced with good ones.
Improper use of LED solid crystal machine
Improper suction parameters
The nozzle height and solid crystal height of the machine are directly controlled by the parameters in the machine computer. Large parameter, small height of solid absorption; small parameter, large height of solid absorption, and whether the chip is damaged is directly affected by the parameter of solid height of the machine. The main reasons for the bad phenomenon are: the machine parameters are large, the hug height is low, and the chip is overloaded, resulting in chip damage.
Solution: Adjust the machine parameters, appropriately raise the height of the nozzle or the solid crystal, and adjust the nozzle height in the first item “Pick Level” in the “Bond head menu” in the machine “SETUP” mode in VDWALL LVP615. Two “Bond Level” adjust the height of solid crystal.
Nozzle size does not match
Different size chips need to be fixed with different nozzles. Large chips use small nozzles, and the chips cannot be sucked easily, and small chips use large nozzles, and the chips are easy to break for safe. Therefore, selecting a suitable nozzle is a prerequisite for good chip fixing. The cause of the undesirable phenomenon is that the suction nozzle is too large, breaking the chip.
Solution: Use appropriate porcelain nozzle.
Rupture caused by improper operation
Failure to operate in accordance with regulations results in chip breaking. The main reasons for the bad phenomenon are: the material is not properly handled, and it falls to the ground; the chip is touched when entering the oven
Solution: When holding the material, hold your hand firmly. When entering the oven, the material should be flat and gently put in. Do not tilt or use too much force.
Heavy object crush
The chip is broken due to excessive external force. The main causes of this undesirable phenomenon are: the microscope is dropped on the material to break the chip program; the machine parts are dropped on the material; the iron plate is pressed onto the material
Solution: The microscope screws should be locked tightly; regularly check whether the machine parts equipment are loose; there should not be any objects such as iron plates on the material.