9.4.2 BGA Component Reballing, Braid Ball Removal, Reflow Oven Attachment Method
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Outline
This procedure covers reballing of BGA components.
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Minimum Skill Level - Expert
Recommended for technicians with advanced soldering and component rework skills and extensive experience in most 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.
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| Procedure References
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| 1.0 |
Foreword |
| 2.1 |
Handling Electronic Assemblies |
| 2.2 |
Cleaning |
| 2.5 |
Baking And Preheating |
| IPC 7711/7721 5.7.3 |
BGA Reballing Procedure - Fixture Method
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| IPC J-STD-033 |
Joint Industry Standard for Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive Surface Mount Device
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| J-STD-001 |
Requirements for Soldered Electrical and Electronic Assemblies
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| GEIA-STD-0006 |
Requirements for Using Solder Dip to Replace the Finish on Electronic Piece Parts
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| Tools and Materials
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Cleaner
General purpose cleaner for removing contamination.
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Cleaning Brushes
Disposable brushes for use with solvents for cleaning and application of coatings.
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Cleaning System
Batch or inline cleaning system for removing fluxes and contamination.
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Desolder Braid
Woven copper wire designed to wick solder from surfaces and holes.
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Gloves
Disposable, puncture-resistant gloves designed for handling mild chemicals.
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Microscope
Precision microscope with stand and lighting for work and inspection.
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Oven
General purpose oven for drying, baking and curing epoxies.
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Reflow Oven
Reflow oven with multiple zones for controlled solder reflow.
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Safety Glasses
Protect your eyes and your vision with proper safety glasses.
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Solder Flux 
Used to prepare solder surfaces and to prevent formation of oxides during soldering.
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Solder Paste
Solder paste for component soldering and rework.
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Solder Spheres
Solder balls or spheres for BGA component reballing and rework.
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Soldering Iron
Properly maintained soldering iron and properly sized soldering iron tips.
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Wipes
Nonabrasive, low-linting wipes for cleanup.
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Proprietary Information
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Images and Figures
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| BGA component prior to reballing. |
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| Figure 1. Remove existing solder spheres on BGA components using desolder braid. |
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| Figure 2. Apply tacky flux to flat BGA component pads using a brush. |
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| Figure 3. Place the BGA component(s) into a fixture and cover with the appropriate stencil. |
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| Figure 4. Reflow oven used for controlled reflow of solder balls. |
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Procedure - Braid Ball Removal
- Ensure all BGA components to be processed meet the requirements for acceptable moisture level.
Note
For information on baking and moisture level control see 2.5 Baking and Preheating
- Remove existing solder spheres on BGA components using desolder braid. Place the desolder braid on the balls to be removed and gently place the soldering iron on the desolder braid. Apply very light pressure to melt the solder balls. As the solder melts it will be drawn onto the copper desoldering braid by capillary action. Repeat as needed to remove all the solder balls. See Figure 1.
- Clean the BGA components with approved cleaning solution. Some cleaning solutions may be specified by customer or contract. Typical cleaning process uses a Cleaning Brush and Cleaner. Gently brush the surface until all evidence of flux and debris have been removed. Dry with a clean Wipe or blow off using an air gun.
Procedure - Reflow Oven Attachment
- Apply tacky flux to the flat BGA component pads using a Brush. Flux should be evenly applied across the entire BGA pad surface. Use minimal flux needed to fully cover the surface. Remove any excess flux. See Figure 2.
- Place the BGA component(s) into a fixture and cover with a matching stencil. Check to ensure the alignment is correct. See Figure 3.
- Place a quantity of the appropriate size Solder Spheres into the fixture and use a clean Cleaning Brush to distribute the Solder Spheres so they fill all the open apertures in the BGA Component Stencil. Check to be sure all the apertures are filled with only one solder sphere. Tilt the fixture and pour the excess Solder Spheres into a collection container for reuse.
Note
Avoid overloading the Solder Stencil with excess Solder Spheres as they may wedge under the stencil. This will make lifting the Stencil to remove any excess Solder Spheres difficult.
- Set up the Reflow oven with the proper profile and run the oven for 5 minutes to ensure the reflow zone temperatures are stable. See Figure 4.
Note
If a profile has not been defined a profile will need to be created.
- Place the BGA fixture and BGA components into the reflow oven. As the fixture moves through the oven the fixture and components will go through the required preheat, reflow and cooling cycles.
- When the fixture and components emerge from the reflow oven use gloves and remove the fixture and place on a flat surface. Allow the fixture and components to cool for one minutes to ensure package thermal stability prior to removing the BGA component from the fixture.
- Visually inspect the BGA components balls for proper alignment and appearance.
- Clean the BGA components in approved cleaning solution.
- Inspect the body of the BGA component for abnormalities.
- Inspect the BGA component for cleanliness.
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Procedure for reference only.
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