IPC 7711A - 第158页

NOTES IPC-771 1A Number: 5.3.1 Revision: Date: 2/98 Subject: Chip Installation P a g e2o f2 Copyright Association Connecting Electronics Industries Provided by IHS under license with IPC Not for Resale No reproduction or…

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EQUIPMENT REQUIRED
Hot air pencil
Hot air tip
Solder paste dispenser
Tweezers
MATERIALS
Solder paste
Cleaner
Solder paste dispense needles
Tissue/wipe
PROCEDURE
NOTE:
Preheating is recommended for sensitive components. (i.e., chip capaci-
tors.)
1. Install tip into hot air pencil.
2. Start with tip temperature of approximately 315°C and change as necessary.
3. Adjust pressure output so hot air scorches a tissue from approximately 0.5 cm
away. (See Figure 3.)
4. Apply a small bead of solder paste to each land using a dispenser. (See Figure
1.)
5. Position component onto lands using tweezers. (See Figure 2.)
6. Direct hot air over component with tip at a distance of 2.5 cm to pre-dry solder
paste. (See Figure 4.)
7. When pre-drying is observed (paste has dull, flat appearance), move tip closer
(0.5 cm) and heat until complete solder melt is observed. (See Figure 5.)
8. Return hot air pencil to its stand.
9. Clean, if required, and inspect.
Figure 1 Apply Solder Paste
Figure 2 Position Component
Figure 3 Adjust Pressure
Figure 4 Pre-dry Paste
Figure 5 Melt Joints
7711A
Rework of
Electronic Assemblies
Revision:
Date: 2/98
Chip Installation
Solder Paste Method/Hot air Pencil
Number: 5.3.1
Product Class: R, F, C, W
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: 5.3.1
Revision:
Date: 2/98
Subject: Chip Installation
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 iron
Chisel or conical tip
Damp sponge
Wood stick or tweezers
MATERIALS
Flux-cored solder
Flux
Cleaner
Tissue/wipes
NOTE
Preheating is recommended for sensitive components (i.e., chip capacitors).
PROCEDURE
1. Remove conformal coating (if any) and clean work area of any contamination,
oxides, residues or fluxes.
2. Install soldering iron tip in handpiece.
3. Start with tip temperature of approximately 315°C and change as necessary.
4. Apply flux to one land (optional).
5. Thermal shock tip with damp sponge.
6. Prefill one land with solder. (See Figure 1.)
7. Place the component in position and hold it with a wooden stick or tweezers.
8. Apply flux to both lands.
9. Place the tip at the junction between the prefilled land and termination area of
component.
10. Observe complete solder melt. This is evident by component dropping down
onto land. area. (See Figure 2.)
11. Pause briefly for solder to solidify
12. Solder remaining side by applying additional solder as needed. (See Figure 3.)
13. Re-tin tip end with solder and return handpiece to its stand.
14. Clean lands as required for component replacement.
Figure 1
Figure 2
Figure 3
7711A
Rework of
Electronic Assemblies
Revision:
Date: 5/02
Chip Installation
Point to Point Method
Number: 5.3.2
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
--``,``,-`-`,,`,,`,`,,`---