8.2.2 Component Removal, Surface Mount Chip Components, Hot Tweezer Method
Outline
This procedure covers one commonly used method for removing surface mount chip components.
Note: The goal when removing any component is to remove the component as quickly as possible.
Caution - Glued Components: A small dot of epoxy is often used to hold chip components in position during wave soldering processing. Typically these components will be located on the bottom side of a circuit board that has through-hole components located on the other side. Whenever you see a board like this, you can generally assume that the chip components will be glued onto the board. You'll need to leave the tip on the component for one or two additional seconds in order to transfer enough heat to over-cure or soften the adhesive. If required, take a wooden stick or curved tweezers and push the component sideways until the glue joint finally gives way.
Minimum Skill Level - Intermediate
Recommended for technicians with skills in basic soldering and component rework, but may be inexperienced in general repair/rework procedures.
Conformance Level - High
This procedure most closely duplicates the physical characteristics of the original, and most probably complies with all the functional, environmental and serviceability factors.
Flex-Rack PCB Holder
Sturdy holder supports PCBs for rework, drilling, pad repair, and positioning.
Precision Tool Set
Nine precision-crafted tools for detailed circuit board work.
Additional Items and Supplies
Cleaner
General purpose cleaner for removing contamination.
Microscope
Precision microscope with stand and lighting for work and inspection.
Soldering Iron
Properly maintained soldering iron and properly sized soldering iron tips.
Wipes
Nonabrasive, low-linting wipes for cleanup.
Images and Figures
Surface Mount Chip Component
Figure 1: Place the tweezer tips in position. When the solder melts, lift the component off the circuit board.
Chip Capacitors generally have solid color bodies.
A - Stripe;B - Beveled Surface;The striped or beveled end is the "positive" (+) or "anode end".
Note: Determine the direction the part is to be swept off the circuit board surface. Densely packed circuit board assemblies often leave only one direction for the rework tool to follow when sweeping the part off the surface
Procedure
Tin the hot tweezer tip.
Apply a small amount of liquid flux to both ends of the component.
Place the tweezer tips in contact with both ends of the component. When the solder melts, lift the component off the circuit board. (See Figure 1)