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7.5.2 Soldering Surface Mount Gull Wing Components, Continuous Flow Method
Outline
This procedure covers the general guidelines for soldering surface mount Gull Wing components. There is basically only one type of Gull Wing component. Whether leads are on two sides or four sides, or whether the component is large or small, the soldering principles are the same.

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.

Acceptability References
IPC-A-610 12.0 Surface Mount Assemblies
Procedure References
1.0 Foreword
2.1 Handling Electronic Assemblies
2.2 Cleaning
2.5 Baking And Preheating
7.1.1 Soldering Basics
7.1.2 Preparation For Soldering And Component Removal
7.1.3 Solder Joint Acceptability Criteria
IPC7711 5.5.1 Multi-Lead Method - Top of Lead
IPC7711 5.5.2 Multi-Lead Method - Toe Tip
Tools and Materials
Cleaner
Cleaner
General purpose cleaner for removing contamination.
Microscope
Microscope
It is a challenge to undertake precision repair without a good microscope.
Soldering Iron
Soldering Iron, Solder and Flux
A well maintained soldering iron is a must at every tech bench.
Wipes
Wipes
Nonabrasive, low-linting wipes for cleanup.
Images and Figures
7.5.2 Soldering Surface Mount Gull Wing Components, Continuous Flow Method
Surface Mount Gull Wing Component
7.5.2 Soldering Surface Mount Gull Wing Components, Continuous Flow Method
Figure 1: Place component and check alignment.
7.5.2 Soldering Surface Mount Gull Wing Components, Continuous Flow Method
Figure 2: Apply solder to the continuous flow solder tip to create a convex bead of molten solder.
7.5.2 Soldering Surface Mount Gull Wing Components, Continuous Flow Method
Figure 3: Slowly move the tip over the row of leads to form proper solder fillets at each joint.

Procedure 
  1. Add liquid flux to the corner pads.

  2. Place the component in position and hold it steady. The leads must be aligned with the pads. On large components this is best done by aligning the leads on opposite corners. (See Figure 1)

  3. *Place the soldering iron tip at the junction between the pad and component lead at one of the corners. Apply additional solder as needed.

  4. Remove the tip. Wait a moment for the solder to solidify before soldering the opposite corner.

  5. Apply solder to the continuous flow solder tip to create a convex bead of molten solder on the tip. (See Figure 2)

  6. Position the solder tip so that the solder bead contacts the top portion of the leads. Slowly move the tip over the row of leads to form proper solder fillets at each joint. (See Figure 3)

  7. Repeat steps 5 and 6 for the remaining sides.

  8. Clean, if required and inspect.

Procedure for reference only.