The picture shows the comparison between 0402, 0201, 01005 and the tip of a needle. The FINEPLACER® system is capable of handling these devices successfully - even in a lead free environment. The following explains FINETECH's solutions to the challenges presented by small passives rework.
01005 components are becoming more and more important these days. Preeminent reasons can be summed up in few keywords:
Integration: more functional groups on one PCB
Higher frequencies: esp. in communication or computer technology
Miniaturisation
Environment
Due to the small dimensions of the components a rework system has to face new challenges. For reproducible results with a rework system the following questions should be answered with YES. Is your preferred rework system ...
...capable to make such components visible?
...capable of secure handling of such fragile components with very low mass (0.04g/1000 pcs.)?
...capable of force-controlled handling and placement of such components?
...capable of accurate time and/or temperature defined profiling?
...capable to allow in-situ process observation of the working area?
...capable to place new components with at least 10 µm accuracy?
...capable to apply new solder material with typical dot points of 200 µm?
... easily operatable by trained operators without extreme expertise?
...upgradable with above features?
... a cost efficient rework solution?
These demands make rework of such small components very challenging, a manual rework with solder iron is plainly impossible. Considering the trend to ever smaller components and the introduction of lead-free materials, high demands are set on the rework system. There are five typical kinds of defects which can be subsumed in two general categories.
First category: The components are either missing, misplaced or shifted on the PCB (angular error).
Reasons for this category of defects could be inconsistent component pick-up of the chip shooter, static charges, wrong alignment of the component or component movement after placement due to vibration.
angular error
shifted component
Solution: These kinds of defects have to be repaired by re-adjusting the component (desolder & replace). The residual solder is reused.
The process steps:
Desolder component
Realign component
Place component into residual solder
Reflow component
The FINEPLACER® Pico with new application package for "Micro Rework" is designed for the rework of very small components. Technical features are:
5 µm placement accuracy of the rework system
High magnification video optics
Modified VARIOPlus observing video with extended magnification
LED process lighting
COMISS IVPlus- intelligent thermal management system
Swivel arm with force control
Tool-kit fitting to the application
Second category: component is either "tombstoned" or even broken and must be replaced.
Reasons for this kind of defects during the assembly process could be:
improper solder paste printing
wrong alignment of component
inappropriate reflow profiling (too much heat provided too quickly leads to flux exhaustion)
breaking due to wrong adjustment of placement force
The defects of both categories are often caused by a combination of small problems in one or more of the mentioned reasons.
"tombstoned" component
broken component
Rotation of component (angular error)
Unequal adhesion forces (tombstoning)
For defects of the second category, the component and the solder are sucked off simultaneously. Afterwards, the defect component will be replaced by soldering a new component. The solder paste will be replaced. A high-end dispenser is needed to set fine dots.
The process steps:
remove component
dispense solder paste
place component into new solder paste
reflow component
The FINEPLACER® Pico with new application package for "Micro Rework" and additional high-precision solder paste dispenser is also suitable for this category of defects. Technical features are:
5 µm placement accuracy of the rework system
High-end solder paste dispenser for very small dispense dots
High magnification video optics
Modified VARIOPlus observing video with extended magnification
LED process lighting
COMISS IVPlus intelligent thermal management system
Swivel arm with force control
Solder removal module
Tool-kit fitting to the application
For rework of such small components special tooling is necessary. Especially 01005 small passives set demands for highly precise tools.
The optimally aligned application package "Micro Rework" is available as complete rework system or as kit to retrofit your existing FINEPLACER® Pico to get a perfect configuration for sophisticated rework tasks not only focussed on 01005 components.
