Array Reballing
The accurate placement of a new array of solder spheres is called array reballing. It is advisable if valuable resources (and money) need to be saved or to to extend the value chain.
Array reballing is typically necessary if the assembly line has misplaced the BGA grid array, if the solder paste printer has failed or if PCB pads have oxidized and the solder balls do not connect properly.
The Finetech Solution
Contactless Solder Removal
Manual residual solder removal is not a reproducible process and holds the risk of damaging nearby components as well as solder resist or PCB tracks which could result in a defective board. Therefore, Finetech offers solutions for contactless solder removal in a single sweep which allow a safe, careful and - most important- reproducible dressing even of very small sites on heavily populated boards.
After starting a reflow process, molten solder is easily removed from the board with powerful vacuum. The new generation of solder removal heads allow contactless residual solder removal without disturbing any pads or solder resist. Adjacent components and the PCB will be protected reliably from damage.
Flux Dipping
The use of a tacky flux to hold the ball in place during reflow provides a good surface tension between the interposer and the ball, which helps keep the ball aligned to the pad that it will be soldered to. It provides a good thermal transfer mechanism between the solder on the board and that which makes up the ball. Compare the flux to the grease used to cook an egg. Using a thermal transfer material always makes the job much easier.
Ball Array Placement Module
Reballing Module
BGA Reballing Kit with: frame holder with vacuum support; component support plate; reballing template
The Ball Array Placement Module allows the simultaneous precision placement of solder balls directly onto a substrate or wafer (up to 12 inches). After first executing a flux transfer, a predefined ball array is picked-up, transferred and then re-soldered onto the substrate.
Vacuum control, especially for the smallest ball diameters, guarantees secure pick up and handling as well as deformation-free placement of the balls. Using the Vision Alignment System and high resolution video optics, the balls are accurately placed. A Bonding Force Module provides precise control over the forces used during the entire pick and placement process.
Integrated Process Management (IPM)
Integrated Process Management (IPM)
Principle of process gas integration
Operating software for rework
Operating software for bonding
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
- 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. This is as easy as process development can get.