Ultrasonic tin soldering method

Abstract

The invention provides an ultrasonic tin soldering method. An ultrasonic tin soldering device is included and comprises a rack, a heating device, a discharging mechanism and an ultrasonic mechanism. The discharging mechanism is arranged at the upper end of the rack, and the heating device is arranged at the lower end of the rack. The ultrasonic mechanism is connected with the discharging mechanism. Different tin amounts during tin soldering are controlled according to different sizes of bonding pads; the situation that the size of a bonding pad is large, the tin amount is too small, and consequently an LED chip cannot be stably welded to the bonding pad is avoided; meanwhile, the situation that the size of a bonding pad is too small, the tin amount is too large, the LED chip moves on the bonding pad, and consequently connection is not reliable can be avoided; and the ultrasonic mechanism is used for conducting tin soldering, the tin amount can be accurately controlled, and precision ishigh.

Description

Technical field [0001] The invention relates to the field of Mini LEDs, in particular to an ultrasonic soldering method. Background technique [0002] Mini LED refers to the LED whose package size is 0.1-0.2mm, also known as sub-millimeter light emitting diode. Since the size of miniLED is in the order of 100 microns, and the size of the existing Micro LED is about 50 microns, compared with the existing Micro LED, its size is slightly larger, and its mass production is feasible and can be applied to the backlight of large-size displays . Due to its small size and flexible substrate, mini LED can also achieve a form of high-curved backlight. It adopts a local dimming design and has better color rendering. It can bring finer HDR partitions to LCD panels, and the thickness is also close to OLED. It can save up to 80% of power, so it needs backlight applications such as power saving, thinness, HDR, and special-shaped displays. It is suitable for applications such as mobile phones, ...

AI Technical Summary

Problems solved by technology

[0003] In the existing mini LEDs, tin is generally placed on the pads of the substrate by brushing solder paste. Due to the small size of the mini LED, the size of the corresponding pads is also relatively small. If the paste does not fall on the pad area, it will lead to the problem of unreliable connection, and at the same time, the amount of tin on the pad cannot be accurately controlled; this will cause the thickness of tin on adjacent pads to be inconsistent, and if the amount of tin Too little will lead to unreliable connection between the chip and the substrate, and too much tin will easily move the chip on the substrate when the chip is soldered to the substrate, which will cause the pads of the chip and the pads on the substrate to be out of alignment and connection, resulting in unreliable connection

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