7.5.2 Soldering Surface Mount Gull Wing Components, Continuous Flow Method

Printed Board Type: R/F/W/C
Skill Level: Intermediate
Conformance Level: High
Revision: D
Revision Date: Jul 7, 2000

OUTLINE

Surface Mount Gull Wing Component

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.

ACCEPTABILITY REFERENCES
IPC-A-610 12.0	Surface Mount Assemblies
PROCEDURE REFERENCE
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
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

Figure 1: Place component and check alignment.

TOOLS & MATERIALS
Cleaner
Flux
Microscope
Solder
Soldering Iron with Tips
Wipes

PROCEDURE    Preview a Video Clip   (Size - 500KB)

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. Figure 2: Apply solder to the continuous flow solder tip to create a convex bead of molten solder.

   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. Figure 3: Slowly move the tip over the row of leads to form proper solder fillets at each joint.

   Repeat steps 5 and 6 for the remaining sides.
   
   
8. Clean, if required and inspect.