IPC 7711A.pdf - 第327页
OUTLINE This procedure covers the general guidelines for modifications that involve adding components. REFERENCES 1.0 Index 2.1 Handling Electronic Assemblies 2.2 Cleaning 2.5 Baking and Preheating TOOLS & MATERIALS …
NOTES
IPC-7721A
Number: 6.2.2
Revision:
Date: 10/03
Subject: Jumper Wires, BGA Components, Through Board Method
Page4of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
OUTLINE
This procedure covers the general guidelines for modifications that involve adding
components.
REFERENCES
1.0 Index
2.1 Handling Electronic Assemblies
2.2 Cleaning
2.5 Baking and Preheating
TOOLS & MATERIALS
Cleaner
Cleaning Wipes
Flux
Microscope System
Soldering Iron with Tips
Solder
GENERAL RULES
1. Added components may need to be secured with adhesive, or by other means,
if the component leads or component body would be subjected to mechanical
stress.
2. Leads of added components should not be inserted into plated holes occupied
by another component lead.
3. Added components placed on the circuit board surface should be placed on the
component side of the assembly or circuit board unless otherwise specified.
4. Added components shall not be raised above the board surface beyond allow-
able dimensions.
5. Added components shall not cover over pads or vias used as test points.
6. Added components shall not cover other component foot prints unless the lay-
out of the assembly prohibits mounting in other areas.
7. Added component leads may require insulation to avoid contact with compo-
nent body or other conductors.
8. Removal of existing solder from a connection point may be necessary to avoid
bridging, or excess solder, in the final connection.
9. Consider design limitations and product use environments when stacking com-
ponents.
10. Do not exceed minimum component lead bend radius.
11. When possible, component identification marking shall be legible.
7721A
Repair and
Modification of
Printed Boards and
Electronic Assemblies
Revision:
Date: 03/01
Component Modifications
and Additions
Number: 6.3
Product Class: R,F,W,C
Skill Level: Advanced
Level of Conformance: N/A
Material in this manual 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.
Page1of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
PROCEDURE
1. When required, form the component leads and clean the area.
2. When required, secure the component in place by bending leads or other
mechanical means.
3. Apply flux to the connection.
4. Place the soldering iron tip at the connection between both leads. Apply a small
amount of solder at the connection of soldering iron tip and lead to form a solder
bridge.
5. Immediately feed solder into the joint from the side opposite the soldering iron tip
until the proper fillet is achieved. Remove the solder and iron simultaneously.
6. When required, clean the flux residue.
7. Inspect.
IPC-7721A
Number: 6.3
Revision:
Date: 03/01
Subject: Component Modifications and Additions
Page2of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---