Electronic circuit board BGAQFN surface mount element maintenance process

Abstract

The invention discloses an electronic circuit board BGAQFN surface mount element maintenance process. The process comprises the following operation steps of: 1, printing solder paste on a high-temperature-resistant ceramic chip by using a solder paste brushing copper sheet, and checking whether the solder paste has the phenomena of short circuit and tin insufficiency or not by using a microscope; and 2, placing a QFN surface mount element, melting the solder by using a hot air gun or reflow soldering, checking whether a welding spot has the phenomenon of short circuit and tin insufficiency by using the microscope, and installing the element by using the hot air gun or a reworking table. According to the electronic circuit board BGAQFN surface mount element maintenance process, an original QFN element maintenance method is changed, the solder paste printing steel sheet and the high-temperature-resistant ceramic sheet are used for pre-soldering tin on a QFN body bonding pad, so that the problem that solder paste cannot be printed through the steel sheet, and can only be pre-set through soldering iron after a distribution forbidding area is cancelled can be solved; after the QFN maintenance method is changed, elements without the distribution forbidding area can be maintained by adopting the solder paste printing method, and the maintenance yield is improved by 20%.

Description

technical field [0001] The invention relates to the technical field of electronic circuit boards, in particular to a maintenance process for BGAQFN chip components of electronic circuit boards. Background technique [0002] With the continuous development of today's technology, BGA / QFN is more and more used in various PCBs to replace QFP, PLCC and other components. Its characteristics are: 1) small packaging area; 3) Good reliability; 4) High yield rate of SMT; 5) Good telecommunication performance, etc. [0003] When repairing BGA or QFN components, it is necessary to fix manual printing steel sheets on the BGA pads in advance and use manual printing solder paste, and then use the method of BGA rework station for repairs. However, as electronic products become more and more complex, more and more The smaller the size, the forbidden area of ​​BGA or QFN components is often canceled when designing the PCB layout, which makes it impossible to fix the manual printing steel she...

AI Technical Summary

Problems solved by technology

[0003] When repairing BGA or QFN components, it is necessary to fix manual printing steel sheets on the BGA pads in advance and use manual printing solder paste, and then use the method of BGA rework station for repairs. However, as electronic products become more and more complex, more and more The more miniaturized, the forbidden area of ​​BGA or QFN components is often canceled when designing the PCB layout, which makes it impossible to fix the manual printed steel sheet on the BGA pad when repairing the BGA or QFN, and it is impossible to solder the PCB pad. Printing, based on the above reasons, it is necessary to study new maintenance methods