BGA Rework has become synonymous for SMT Rework in general. Many users’ needs focus around BGA/CSP/Flip Chip, so information found here provides a general background, applicable not only to array packages, but also to the broader SMT Rework market. Large sphere arrays (BGA), and small fine pitch arrays (CSP) demand configurations that combine precise thermal management and high resolution optics, to ensure a void-free rework process and accurate alignment.
BGA Rework - the challenges
- one system for the complete rework cycle - from component removal to re-soldering?
- Large arrays (20-65 mm) need large optical field of view, whereas smaller fine pitch CSP's (0,8-20 mm) need high magnification (both require good resolution)
- Solder removal of irregular shaped residual
- Need to remove the BGA, but leave the neighboring devices undisturbed?!
- Want instant profiling?
- Multilayer board sizes from USB stick (12x40 mm) to server board (500x465 mm)?
The Finetech Solution
Steps of BGA Rework Process
Finetech provides a single platform that can perform the complete rework cycle:
- Melt solder and remove the defective component with a specialized nozzle design
- Residual solder removal using a contactless process - done in a single sweep, it produces safe, reproducible cleaning
- Printing of solder paste on PCB, direct component printing or dispensing
- Reball either a single defective ball or an entire array
- Placement and reflow of new component ensuring accurate alignment
Controlled Mixed Soldering System
Finetech’s unique thermal management concept uses “cold” air or gas (typically nitrogen) introduced into the hot-gas stream in a mixing chamber. The chamber location is just before the air passes through the nozzle onto the component. This gas mixture results in a highly responsive system - reducing over and under-shoot to barely perceptible levels. Tracking of the pre-set temperature is optimized and when combined with mass-flow-control of gas volumes (up to 70L/min), produces an effective heat delivery system. Heater lifetime is also increased and system-to-system reproducibility is greatly enhanced (±2ºC).
Split Field Optics and Zoom Magnification
Integrated Process Management (IPM)
The Integrated Process Management (IPM) is the center piece of a FINEPLACER® system1 - the place where it all comes together. IPM is more than just thermal management. It synchronizes the control of all process modules and their related parameters:
- Controlled and precisely balanced interaction of top and bottom (pre-)heating and cooling
- Control of temperature, time, force, power, energy, flow
- Process-integrated camera and light control
- Controlled process gas integration for reduced solder contamination, minimized surface tension effects and smooth spherical solder residues
IPM is very complex, yet easy to access. Via the GUI of the operating software, the user has perfect control of all required adjustments. Just drag 'n drop to define temperature ramps or activate process modules. All settings are represented in only one profile, making for a very intuitive work flow.
The operating software provides an ever-growing library of profiles for all kinds of processes. It also offers comprehensive data logging functions essential for statistical process control.
In combination with the system-to-system process transfer capability this is as easy as process development can get.
1 FINEPLACER® core offers co-ordinated top and bottom heating but does not support IPM
Recommended Rework Systems
Amongst other factors, the recommended system mainly depends on size and pitch of your component and the required process flexiblity.
Browse our product range or get in contact with your sales contact to figure out the best equipment solution for your needs.