Bga maintenance technology manual information
General
This manual provides detailed information on bga maintenance techniques and aims to help engineers and technicians better understand and master key steps and concerns in bga maintenance. Through this manual, readers can have a comprehensive understanding of bga maintenance techniques and become more responsive in practice。
2. Bga basics
2. 1 bga definition
The bga (ballgridarray) fence is an integrated circuit seal. Compared to the traditional dip (two-bar direct plug-in) sealing, bga sealing can accommodate more inducements within the same area, thus improving the performance and reliability of electronic equipment。
2. 2 bga structure
The bga seal consists mainly of the following components:
Chip: integrated circuit chip。
Welding balls: spherical metals linked to chips and printed circuit boards (pcbs) attract feet。
Ceramic plate: the base that supports welding balls and chips。
Cover the shell: the shell that protects the internal structure。
3. Bga maintenance rationale
Bga maintenance is primarily for the replanting of welding balls and the repair of the shell. Its rationale is as follows:
Removal of sealed casings: bga is removed with specialized equipment and welding balls and ceramic plates are exposed。
Purge: cleaning of ceramic plates and welding balls to remove stains and residues from the surface。
Replant the ball: new welding balls are planted on the ceramic plate, with care to control the distance and height of the welding ball。
Welding: welding devices are used to connect welded balls with welding points on the printed circuit board (pcb)。
Solidification: welding balls are strongly connected to the pcb welding points by heating them up。
Testing: functional testing of bga after maintenance to ensure that its performance is satisfactory。
4. Bga maintenance tools and equipment
The following tools and equipment are required for bga maintenance:
Hot wind gun: used to heat up during the removal of the bga envelope and welding。
Tin pumps: for removing welding points on pcb。
Microscope: used to observe micro-components。
Welding material for welding。
Welding table: fixed bga and pcb to ensure stability of welding process。
Planting machines: for automating the planting process。
Detection equipment: for functional testing of bga after maintenance。
5. Bga maintenance operational steps
5. 1 preparatory phase
Know the type and form of the bga to be repaired。
Prepare appropriate maintenance tools and equipment。
Ensure that the working environment is clean and clean and that pollution is avoided。
5. 2 dismantling phase
Heated bga with a heater to deform and deform it。
Slightly vibrating pcb, auxiliary shell falling。
Check ceramic plates and welding balls to remove residual casings and stains。
5. 3 maintenance phase
Welding points on pcb are removed from the use of styl pumps。
Cleaning of ceramic plates and welding balls to ensure clean surfaces。
Welding ball spacing and height are controlled using a pyroscope or hand-planted ball。
Welding balls and pcb dots to make sure the connection is strong。
5. 4 solidification and testing phase
Heated welding points and strong connections。
Use microscopes to check weld point quality。
Perform functional tests to validate performance after bga maintenance。
6. Attention
During maintenance, it is important to keep the working environment clean and to avoid contamination。
When operating the hot wind gun, be careful to control the temperature and heating time and avoid damage to the pcb and the welding points。
During welding, the quality of welding is ensured and welding is avoided, such as welding, cold welding, etc。
During solidification, care is taken to control the heating temperature and time and to ensure that welding points are strong。
Upon completion of maintenance, functional tests are conducted to ensure that bga performance is in compliance。
7. Concluding remarks
The manual provides details of the rationale, tools, equipment and operational steps of bga maintenance technology, which is expected to be of assistance to engineers and technicians working in the area of electronic maintenance. In practice, please apply the flexibility applied on a case-by-case basis to continuously improve their maintenance skills。
8. Common bga containment type and maintenance strategy
The structure and rationale of different bga envelope types may differ. The following are some of the most common types of bga sealing and corresponding maintenance strategies:
8. 1 qfn (quadflat noleads) seal
The qfn envelope is characterized by a flow of feet spread over the four sides of the envelope, with no thrust. Maintenance strategy:
Heated wind guns were used to deform the bottom。
Remove the welding point with a suction pump。
Cleaning ceramic plates and welding balls。
Replant the ball and weld it。
Welding and functional testing。
8. 2 lga seal
Lga is sealed on the bottom of the encapsulation in a grid. Maintenance strategy:
Heated wind guns were used to deform the bottom。
Slightly vibrating pcb, auxiliary shell falling。
Check the ceramic plates and welding balls, remove the remaining shell and dirt
