Method for maintaining AQFN (Advanced Quad Flat No-Lead Package) mobile phone motherboard and maintenance table

Abstract

The invention discloses a method for maintaining an AQFN (Advanced Quad Flat No-Lead Package) mobile phone motherboard and a maintenance table. The method comprises the following steps of: 1, fixing the motherboard to be maintained, an upper air gun and a lower air gun on respective fixing tables which are adjusted in place respectively; 2, setting proper temperature and air speed of the upper air gun and the lower air gun respectively; 3, simultaneously starting the upper air gun and the lower air gun for heating and unsoldering; 4, cleaning a bonding pad; 5, smoothly coating a solder wire of the bonding pad; 6, performing chip balling; and 7, simultaneously starting the upper air gun and the lower air gun for heating and reflow soldering. The maintenance table comprises a pedestal 1, a stand 2, a lower air gun fixing table 3, a motherboard fixing table 4 and an upper air gun fixing table 5, wherein the stand 2 is fixed at a middle position of the pedestal 1; the lower air gun fixing table, the motherboard fixing table and the upper air gun fixing table are sleeved on the stand respectively; and each fixing table is provided with an adjusting, locking and fixing structure opposite to the stand. The maintenance method and the maintenance table have the advantages of high maintenance efficiency and low reject ratio; and the maintenance table is low in cost, has small occupied area and is suitable to be arranged on a mobile phone production line.

Description

technical field [0001] The invention relates to a method for repairing the motherboard of an AQFN mobile phone and a repair platform specially used for the repair method. Background technique [0002] QFN (Quad Flat No-lead Package) is a surface-mount chip packaging technology with small pad size, small volume, and plastic as the sealing material. Since the large exposed pad in the center of the bottom is soldered to the heat dissipation pad of the PCB, QFN is relatively incompatible with BGA chip packaging technology (Ball Grid Array Package, that is, ball grid array packaging technology) or TFBGA technology (Thin Fine-Pitch Ball Grid Array) ,), with excellent electrical and thermal properties. [0003] AQFN (Advanced QFN) is an improved QFN packaging technology. Unlike general QFNs, the pins of AQFN protrude, unlike traditional QFNs where the pins are flush with the chip packaging (molding). From the appearance, AQFN and TFBGA are a bit similar, but in actual packaging,...

AI Technical Summary

Problems solved by technology

[0015] Due to the above reasons, in order to complete the maintenance, the temperature setting of the heat gun needs to be very high, reaching 360-390°C, and the heating time for maintenance needs to be very long, 7-10 minutes

[0016] (2) Long-term high-temperature maintenance leads to a large number of waste products

However, using this rework station, the maintenance efficiency is too low, and the maintenance time for a single chip takes 8 to 10 minutes; calculated based on 20 hours of work per day, the daily maintenance capacity of each device is 120 motherboards

Moreover, the system of this rework station is complicated, equipped with a computer control system, and the cost is relatively high, each of which is more than RMB 100,000

In addition, this rework station originally used for repairing computer motherboards occupies a relatively large area of ​​1.5 square meters. It is not suitable to be deployed on mobile phone production lines, and it is only suitable for piecemeal repairs.

[0023] Therefore, this type of BGA computer motherboard rework station is not suitable for AQFN product repair equipment on mobile phone production lines

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