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.

   

ACCEPTABILITY REFERENCES
IPC-A-610	12.0	Surface Mount Assemblies
PROCEDURE REFERENCE
CTC 7721	1.0	Foreword
CTC 7721	2.1	Handling Electronic Assemblies
CTC 7721	2.2	Cleaning
CTC 7721	2.5	Baking and Preheating
CTC 7711	7.1.1	Soldering Basics
CTC 7711	7.1.2	Preparation For Soldering
CTC 7711	7.1.3	Solder Joint Acceptability Criteria
IPC 7711	5.5.4	Hot Air Pencil/Solder Paste Method

TOOLS & MATERIALS
Cleaner
Flux
Hot Air Tool with Tips
Microscope
Solder Paste
Wipes

PROCEDURE

1. Add a small bead of solder paste along the row of pads. (See Fig. 1).



2. Place the component in position.



3. Adjust the pressure and temperature output of the hot air tool.



4. Direct the hot air over the component with the hot air tool tip approximately 2.50 cm (1.00") from the solder joint. This initial heating will pre-dry the solder paste.
   
   

   NOTE
   Solder paste has a dull flat appearance when dried.




5. When the solder paste has dried, move the hot air tool tip to approximately 0.50 cm (0.20") above the component. Move the tool back and forth to heat all the solder joints until complete solder melt is observed. (See Figure 2).



6. Remove the tool. Wait a moment for the solder to solidify.



7. Clean, if required and inspect.