Dual-mode hybrid control flip chip mounting method

Abstract

The invention discloses a dual-mode hybrid control flip chip mounting method. The method comprises the steps that a mounting head is driven to move in a position mode; the contact force between a chipand a substrate is measured; mode switching is started at the moment when the contact force is larger than a set threshold value, the position mode output quantity u and the force mode output quantity u<f> are respectively multiplied by a function related to a weight factor [eta] and [eta] is continuous and derivable in a defined interval, the position mode is switched into the force mode within a mounting switching time period [delta], and no impact is generated in the switching process; after switching is completed, the force mode output quantity u<f> applies pressure to the chip; and after a period of time of pressing, the mounting head is controlled to move reversely to complete the flip chip mounting process, and the next flip chip mounting process can be carried out. According tothe flip chip mounting method, smooth switching between the two modes is achieved, the position mode and the force mode exist within the mounting switching duration at the same time, sudden switchingis avoided, the set threshold value of the pressure appears before following errors, and control is achieved more accurately.

Description

Technical field [0001] The invention relates to the technical field of chip flip-chip packaging, and further relates to a dual-mode hybrid control chip flip-chip method. Background technique [0002] Flip chip is a leadless structure and generally contains circuit units. In the field of chip flip-chip bonding, chip bonding is the most critical part of flip-chip bonding. In the chip bonding process, the chip is carried by the placement head and transferred to the substrate. Due to the extrusion between the placement head and the chip, the larger Force impact is likely to cause cracks in the chip, resulting in the failure of the chip and antenna interconnection; in order to ensure the reliability of the paste package, after the chip is placed on the substrate pad, the placement head needs to be pressed for a period of time with a certain contact force, but it cannot The chip is crushed during the contact process. [0003] In order to prevent the chip from being crushed, it is neces...

AI Technical Summary

Problems solved by technology

[0004] The traditional switching method controls the movement of the placement head by monitoring whether the following error exceeds the threshold in real time. The generation of the following error depends on the blocking force. When the following error exceeds the threshold, a large impact has been exerted on the chip, which may cause chip damage.

[0005] Moreover, it is difficult to determine the threshold of following error. If the threshold is set too small, if the PID parameters are incorrect or frictional resistance and other factors occur during high-speed motion, the following error will increase sharply, and the chip will stop moving before reaching the substrate, resulting in placement Failed; if the threshold is set too high, the impact on the chip will be too large, which will easily damage the chip

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