10.7 Component Reclaim, Leadless Components

Outline

This procedure outlines the process for reclaiming leadless components for reuse.

Minimum Skill Level - Expert

Conformance Level - High

Tools and Materials

BGA Rework System Hot air or infrared BGA component rework system.

Cleaner General purpose cleaner for removing contamination.

Cleaning System Batch or inline cleaning system for removing fluxes and contamination.

Gloves Disposable, puncture-resistant gloves designed for handling mild chemicals.

Heat Gun Temperature adjustable heat gun used for a range of heating applications.

Hot Air Tool Tool and nozzles to deliver precise flow of hot air.

Hot Plate Temperature adjustable heated plate to pre-heat components and circuit boards prior to tinning and reflow.

Microscope Precision microscope with stand and lighting for work and inspection.

Oven General purpose oven for drying, baking and curing epoxies.

Solder Flux Used to prepare solder surfaces and to prevent formation of oxides during soldering.

Wipes Nonabrasive, low-linting wipes for cleanup.

Procedure

1. Ensure the components meet the acceptable Moisture Sensitivity Level (MSL) for processing. 
   Note: For details on baking and moisture control, refer to Procedure 2.5 Baking and Preheating..
2. Remove conformal coating from the component if present. See Section 2 for conformal coating removal guidelines.
3. If needed, clean the rework area to remove contamination, oxides, or residues. 
4. Secure the circuit board in a board holder (See Figure 2) or on the base of the rework tool or system (See Figures 3 and 4). A hot plate may be used to provide added bottom-side heating. 
5. Install the appropriate size nozzle based on the component type. Set system controls to the required settings to minimize thermal stress and prevent overheating.
6. Apply flux to component leads. (See Figure 5)
7. Align the component under the nozzle. (See Figure 6)
8. Lower the nozzle, check the alignment, and adjust as needed. 
9. If a vacuum lift is available, lower the vacuum pickup until it contacts the component.
10. Initiate the hot gas reflow cycle, observing the solder melt on all leads. Then activate the system vacuum and raise the nozzle and component a minimum of 25mm above the circuit board. (See Figure 6)
11. Turn off the heated air flow while maintaining the vacuum to retain the component.
12. Allow the component to cool for at least 10 seconds before removal.
13. Clean the component as required. Visually inspect for cleanliness and physical condition.
14. If the component is to be resoldered manually, lead restoration may not be required. If the component will be processed using automatic placement equipment, or if the specification requires specified lead finish conditions, refer to Section 11.

Evaluation

1. Visual examination
2. Tests or other inspection criteria as specified.

Images

Component Reclaim, Leadless Components

Select the proper nozzle based on the component size.

Secure the circuit board in a board holder or on the base of the rework system. A hot plate may be used to provide added bottom-side heating.

Typical hot-air rework tool.

Typical hot-air rework system.

Apply flux to the component terminations.

Direct hot air over the component until complete solder melt has been observed. Then lift the component off the board surface.