QFP packaging chip welding method

Abstract

The invention provides a QFP packaging chip welding method in the technical field of chip welding. The QFP packaging chip welding method comprises the steps: preparing a welding steel mesh; placing the welding steel mesh on a PCB of a QFP packaging chip to be welded, and enabling the first through hole and the second through hole to be aligned with the welding position; printing solder paste on the welding steel mesh, so that the solder paste permeates into the first through hole, the second through hole and the extension part; taking down the welding steel mesh from the PCB, and placing the pins of the QFP packaging chip to be welded on the solder paste of the PCB based on the welding positions; heating the solder paste on the PCB is heated, enabling the solder paste located below the grounding bonding pad to adsorb the grounding bonding pad upwards after being heated, enabing the solder paste located below the pins to be fused with the pins after being heated, and completing the welding of the QFP packaging chip. The method has the advantages that the pseudo soldering rate of QFP packaging chip soldering is greatly reduced, and the product yield is improved.

Description

technical field [0001] The invention relates to the technical field of chip welding, in particular to a QFP package chip welding method. Background technique [0002] As the integration of electronic chips becomes higher and higher, QFP packaging technology emerges as the times require. The QFP package is the quad flat package technology (Quad Flat Package), which is a flat package with four side pins. It is one of the surface mount packages. The distance between them is small and the pins are thin. It is generally used in large-scale or very large-scale integrated circuits, and the number of pins is generally more than 100. [0003] For the soldering of QFP packaged chips, traditionally, a flat steel mesh is used to print solder paste on the position to be soldered. However, the traditional method has the following disadvantages: due to the many pins of the QFP packaged chip, and the pins are not on the same plane as the ground pad in the middle, the pins will be higher t...

AI Technical Summary

Problems solved by technology

However, the traditional method has the following disadvantages: due to the many pins of the QFP packaged chip, and the pins are not on the same plane as the ground pad in the middle, the pins will be higher than the ground pad by a certain distance, and there is a height difference, which often leads to The ground pad cannot be effectively soldered, and it is prone to false soldering during mass production

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