The rework station is also called the rework system, which is used to rework the circuit board's BGA, CSP, QFP, PLCC, SOIC and other surface mount components (SMD). SMD rework station is mainly composed of top heating body, bottom heating body, optical alignment system, temperature feedback system, overall structure, pcb fixture, PC and operating software. Because the solder joints of the BGA are invisible at the bottom of the device, re-soldering the BGA requires a rework system with a spectroscopic vision system to ensure accurate alignment when mounting the BGA.
BGA rework equipment requirements:
● With Vision image alignment system;
● It is better to have a temperature curve test function;
● With bottom heating function, it can preheat the bottom of the PCB to prevent warping;
●When using hot air heating method, choose as many nozzle types as possible;
● For long-term consideration, we can repair CSP, flip chip, POP and other new packaged devices.
Different pcb manufacturers, the difference between their repair systems is mainly due to different heating sources, or different ways of hot air flow. Commonly used heating sources are hot air, infrared, hot air ten infrared.
1.Hot air rework system
Also called hot air rework station, it is the most commonly used rework system. The hot air rework station is mainly composed of the host controller system, hot air heating system, heating system at the bottom of the workbench, worktable holding the printed board, aligment spectroscopic system, high resolution camera and color monitor. The temperature curve can be monitored and adjusted at any time during rework.
The main features of the hot air rework system: it is not easy to damage the SMD and the substrate or surrounding components; different SMDs require different nozzles; and PCB design needs to consider leaving 3-5mm rework space.
2. Infrared heating rework system
The infrared heating rework system uses infrared heating, and the centering adopts a spectroscopic (red and white) system. The visual centering and heating are separated into two places, that is, the visual centering, the device is mounted, and then the table is moved below the heater for welding . If equipped with an endoscope inspection system, real-time images of the two settlements of the solder ball during BGA and CSP welding can be observed.
The main features of the infrared heating rework system are: no nozzle is required for rework, and the design needs to consider leaving a small space for rework; it is more suitable for rework of high-density pcb assembly boards (such as mobile phone circuit boards), and can also repair SMD and other SMD devices and Through-hole components.
3. Hot air-infrared rework system
Hot air-infrared rework system is heated by hot air at the top and infrared preheated at the bottom. The hot air-infrared rework system combines the advantages of hot air and infrared rework systems; rapid heating; sufficient pre-heating at the bottom to achieve heating of the entire board and uniform temperature; more suitable for rework of large boards and lead-free products.