Wafer hot-pressing ultrasonic ball planting device and process

Abstract

The invention discloses a wafer hot-pressing ultrasonic ball planting device and a process thereof. The ball planting device comprises a heating table, an ultrasonic rod and a chopper. A heating coil is wound on the chopper. The heating coil is connected with a power supply through a switch. A temperature measuring device is connected with a power control module. The power control module is connected with the power supply. The power control module controls the power of the power supply according to the head temperature of the chopper detected by the temperature measuring device, so that the head temperature of the chopper is maintained at a desired level. According to the technical scheme of the invention, the chopper is heated to a required process temperature by the heating coil, and a golden wire in the chopper is also heated. Meanwhile, the ultrasonic energy is transmitted to the chopper through the ultrasonic rod. Under the combined action of the friction heat and the heat transferred from the heating coil to the golden wire, the golden wire is melted and the ball planting process is completed. According to the technical scheme of the invention, the chip burning problem on the wafer can be solved. Meanwhile, the displacement of patterns on the wafer is avoided, and the ball planting efficiency is high.

Description

technical field [0001] The invention relates to the improvement of wafer ball planting technology, specifically refers to a device and a process for ball planting a wafer by using hot-press ultrasonic technology, and belongs to the technical field of wafer ball planting. Background technique [0002] In the miniaturization of CSP (Chip Scale Package) for surface acoustic wave (SAW) filters, a ball-attach operation is performed on a patterned wafer, which is then flipped onto a substrate. The ball planting process is used to replace the original lead process, so that the chips on the wafer can be connected with external circuits. [0003] figure 1 It is a schematic diagram of ball planting on a wafer in the prior art. The ball planting process mainly involves a heating table 1 , an ultrasonic bar 2 and a rivet 3 , and the rivet 3 is installed at the front end of the ultrasonic bar 2 . During ball planting, the wafer is placed on the heating table, and the heating table is h...

AI Technical Summary

Problems solved by technology

The existing ball planting process has the following disadvantages: 1. Directly heat the wafer, which may cause burn hazards to the chips on the wafer due to the increase in temperature; 2. Heat the wafer through a heating table, in order to minimize the heat of the device Discharge effect requires slow heating, long heating time, and low ball planting efficiency; 3. Due to the anisotropy of thermal expansion of the wafer, if it is directly heated, the graphics on the wafer have displacement problems, which increases the recognition of graphics by the equipment time

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