IPC 7711A.pdf - 第146页
NOTES IPC-771 1A Number: 4.1.2 Revision: Date: 2/98 Subject: Surface Mount Land Preparation P a g e2o f2 Copyright Association Connecting Electronics Industries Provided by IHS under license with IPC Not for Resale No re…
EQUIPMENT REQUIRED
Continuous vacuum desoldering system
Desoldering tip
Damp sponge
MATERIALS
Flux-cored solder
Flux
Cleaner
Tissue/wipes
PROCEDURE
1. Remove conformal coating (if any) and clean work area of any contamination,
oxides, residues or fluxes.
2. Install appropriate desoldering tip into handpiece.
3. Start with tip temperature of approximately 315°C and change as necessary.
4. Apply flux to all land areas. (See Figure 1.)
5. Thermal shock tip with damp sponge.
6. Tin bottom of tip with solder. (See Figure 2.)
7. Lower tip contacting end of row lands with tip. (See Figure 3.)
8. Confirm solder melt of contacted lands, apply vacuum and sweep tip over
remaining lands in all rows holding tip in contact with solder to extract excess
solder from PWB lands. (See Figure 4.)
9. Lift tip at end of last row, hold vacuum to clear all molten solder from the heater
chamber. (See Figure 5.)
10. Re-tin tip end with solder and return handpiece to its stand.
11. Clean lands as required for component replacement.
Figure 1 Flux Lands
Figure 2 Tin Tip
Figure 3 Position Tip
Figure 4 Melt Solder & Apply Vacuum
Figure 5 Lift Hand Piece
7711A
Rework of
Electronic Assemblies
Revision:
Date: 2/98
Surface Mount Land Preparation
Continuous Method
Number: 4.1.2
Product Class: R, F, W, C
Skill Level: Intermediate
Level of Conformance: High
Material in this manual, IPC-7711 Rework of Electronic Assemblies, was voluntarily established by Technical Committees of
IPC. This material is advisory only and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the
use, application, or adaptation of this material. Users are also wholly responsible for protecting themselves against all claims
or liabilities for patent infringement. Equipment referenced is for the convenience of the user and does not imply endorsement
by IPC.
Page1of2
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
NOTES
IPC-7711A
Number: 4.1.2
Revision:
Date: 2/98
Subject: Surface Mount Land Preparation
Page2of2
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
EQUIPMENT REQUIRED
Soldering system
Soldering handpiece
Chisel tip
Damp sponge
MATERIALS
Wicking braid
Flux
Cleaner
PROCEDURE
Caution:
The wicking method is not recommended for the removal of solder joints
in plated-through holes.
1. Remove conformal coating (if any) and clean work area of any contamination,
oxides or residues.
2. Install chisel tip into soldering handpiece.
3. Start with tip temperature of approximately 315°C and change as necessary.
4. Apply flux to lead/land areas. (See Figure 1.)
5. Remove old solder from tip and thermal shock tip with damp sponge. (See Fig-
ure 2.)
6. Place prefluxed braid on the solder to be removed. Place iron tip on the braid.
Ensure the braid contacts only the solder and the tip contacts only the braid to
prevent damage. (See Figure 3.)
7. When the observable solder flow due to solder wicking action has ceased,
remove both the soldering iron and solder braid from the solder being removed
and allow the area to cool to room temperature. (See Figures4&5.)
8. Repeat steps4-7forallremaining lead/land areas.
9. Re-tin tip with solder and return handpiece to stand.
10. Prepare lands for component replacement.
Figure 1 Apply Flux
Figure 2 Clean Tip
Figure 3 Place Braid & Iron on Land
Figure 4 Solder Flows on Braid
Figure 5 Lift Both Iron & Braid
7711A
Rework of
Electronic Assemblies
Revision:
Date: 2/98
Surface Solder Removal
Braid Method
Number: 4.1.3
Product Class: R, F, W, C
Skill Level: Intermediate
Level of Conformance: High
Material in this manual, IPC-7711 Rework of Electronic Assemblies, was voluntarily established by Technical Committees of
IPC. This material is advisory only and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the
use, application, or adaptation of this material. Users are also wholly responsible for protecting themselves against all claims
or liabilities for patent infringement. Equipment referenced is for the convenience of the user and does not imply endorsement
by IPC.
Page1of2
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---