 |
Package-on-Package (PoP) Rework |
|
|
PoP Rework requires an approved PoP nozzle with clamping solution as well as smart combination of efficient and selective bottom heating and precise top heating. Using advanced bottom and top heating helps avoiding PCB warpage as well as top package warpage and ensures a shorter overall profile run time (higher ramp rates). At the same time, the PCB underside temperature can be kept at lower temperatures to expose PCB and components to as minimal stress as possible.
Requirements for successful PoP Rework:
- no mechanical lateral movement
- sufficient force for lifting out of the liquid solder
- no touch and misalignment of neighbored components also on densely populated PCBs
- one single nozzle for desoldering and soldering
- advanced bottom and top heat supply with minimal stress to component
- lead-free repair according to the JEDEC guideline (DoE)
|
|
|
|
| PoP Soldering Head: Active Clamping Nozzle | |
|
|
| |
|
|
| The PoP soldering head is an easy-to-use tool for reworking stacked devices as a whole in a single reflow process. It uses vacuum-actuated mechanical clamping tweezers which avoid separating the single layers of a PoP during component removal. The PoP soldering head can be easily adapted to different component thicknesses. Furthermore it is possible to adjust the width of the clamping tweezers prior to the process when the rework arm is swiveled down to avoid affecting other components on the PCB (e.g. accidental shifting of neighboring small passives).
The video shows how a PoP package can be freely clamped by the mechanical tweezers (e.g. prior to the removal process). |
| |
|
|
Benefits:
I. Clamping Tweezers optimized for PoP Rework
- flexible clamping width according to the size of the PoP component and its clearance to surrounding components
- ultra thin clamping tweezers allow working even in clearances of 0,3 mm
- conic tweezers design allows free choice of which component of the stack should be clamped
- safe hold of the component
II. Arbitrary starting point and ending point of clamping
- freely programmable for better workflow
(controlled clamping for pick-up of reflowed component, controlled component removal from reflow nozzle)
- time-controlled synchronized clamping, no stress to solder joints
III. FINETECH approved nozzle design
- broad range of possible nozzle sizes
- all nozzles can be easily readapted to different component thickness by the customer
|
|
|
|
| Advanced Heat Input for PoP Rework | |
|
|
| |
|
|
For soldering or changing modern, high-pin-count ICs on high density assembled boards and other substrates, FINETECH has developed the hot gas soldering system COMISS. This module transforms the FINEPLACER® system into a high precision rework station. By goal-directed and exactly defined heat input, soldering tasks can be solved that formerly required hot bar or could not be solved at all.
Temperature control is performed using FINETECH's COMISS (COntrolled MIx Soldering System) which mixes heated and unheated gas. Perfect control of all process parameters means superiority over competing systems: This gives optimal results with minimal stress to the component. The COMISS module is controlled by the reflow software WinCOMISS.
The enhanced COMISS version IVPlus was specially developed for the demands of mobile device rework. It supports in-field auto-calibration and further improvement of process reliability. By auto-calibrating the integrated measuring system of the reflow module, possible production tolerances can be compensated.
Benefits:
- Contactless heating with hot gas
- Capability to use nitrogen
- Easy switching between hot gas and nitrogen for economic use
- Lowest possible thermal load to board and component
- Short soldering time, minimal thermal stress on chip's surroundings
- Rapid cool down after reflow, resulting in small-grained solder joints
- Exact keeping to required temperature
- Excellent reproducibility of soldering profiles
- Safe temperature management, even during long soldering times
- Changing of soldering tools takes just a few seconds
- Auto-calibration
|
|
|
The localized Hot Gas Bottom Heating RB07 is used when defined areas of the PCB are going to be heated preferably. The substrate or PCB will be heated from the underside by hot gas, conveyed by a tube beneath the PCB and directed to the soldering place bottom region. The nozzles are exchangeable against four diffuser sizes. Bottom heater RB07 must be used together with the micro controller driven hot gas reflow module COMISS.
This bottom heating is especially suitable for rework of mobile devices (cell phones, PDA's pacemakers, handhelds ...).
| Technical Specifications |
| Max. Air Temperature at nozzle |
360°C |
| Steadiness of Air Temp. at nozzle |
± 3% |
| Required Air Flow |
80 Nl/min at 6 bar |
| Heating Power |
900 W |
| Standard Diffuser Nozzle |
12 mm x 12 mm |
| Large Diffuser Nozzle |
100 mm x 100 mm |
| Octagonal Diffuser Nozzle |
56 mm x 56 mm |
| Small Diffuser Nozzle |
50 mm x 100 mm |
|
|
|
FINEPLACER® Pico RS (Modular rework system for smallest components and mobile devices)
FINEPLACER® Micro RS (Modular rework system for advanced and standard rework)
FINEPLACER® Jumbo (Modular rework system for very large board sizes)
FINEPLACER® CRS (Compact rework system for advanced and standard rework)
*the configuration shown on the picture may contain optional modules |
|
|
|
|
|
