Method for reducing conformal coatingbubble rate of QFP (Quad Flat Package) integrated circuit chip

Abstract

The invention discloses a method for reducing the conformal coating bubble rate of a QFP packaging integrated circuit chip, which comprises a QFP packaging chip, the QFP packaging chip comprises a packaging chip body and four rows of pin mechanisms uniformly arranged at the periphery of the packaging chip body, a coating surface is formed on the surface of the packaging chip body. An exhaust channel is formed between every two adjacent groups of pin mechanisms, each pin mechanism is composed of a plurality of groups of chip pins, every two adjacent groups of chip pins are arranged at equal intervals. The three-proofing paint coating method of the QFP packaging chip comprises the following steps that firstly, discontinuous circuit pre-coating treatment is conducted on the chip pins; secondly, standing, exhausting and outflow treatment; and thirdly, continuous spraying treatment is conducted. According to the method, intermittent line spraying is adopted, pins on the four sides of the periphery of the chip are pre-coated, four corners of the chip are reserved for exhausting, three-proofing paint is siphoned to the bottom of the chip after standing and buffering, then a continuous line is adopted to coat the whole surface of the chip, and the QFP packaging bubble rate can be effectively improved.

Description

technical field [0001] The invention relates to the technical field of conformal paint coating for QFP packaging, in particular to a method for reducing the bubble rate of conformal paint coating for QFP packaging integrated circuit chips. Background technique [0002] QFP packaging means square flat packaging technology. Generally, large-scale or very large-scale integrated circuit chips adopt this packaging form, and the number of pins is generally more than 100. The distance between pins of the CPU chip implemented by this package is very small, and the pins are very thin, so there is a one-time pass problem in spraying. Conformal paint is a commonly used protective coating in the PCBA processing industry and can be used to protect QFP packages. The components are protected from the erosion of water and salt spray in the environment. Conformal paint has good high and low temperature resistance performance. After curing, it forms a transparent protective film, which has e...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for reducing the rate of air bubbles in the conformal paint coating of QFP-packaged integrated circuit chips, which solves the problem that the conformal paint will flow into the bottom of the chip from the four sides of the chip at the same time, and the air at the bottom of the chip has no discharge channel to form bubbles

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