IPC 7711A - 第311页

OUTLINE This procedure covers the repair/modification of printed boards and electronic assemblies by the use of jumper wires to complete electrical continuity between two points. This procedure is meant to provide a foun…

NOTES

IPC-7721A

Number: 5.3

Revision:

Date: 2/98

Subject: Plated Hole Repair, Inner Layer Connection

Page4of4

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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OUTLINE

This procedure covers the repair/modification of printed boards and electronic

assemblies by the use of jumper wires to complete electrical continuity between two

points. This procedure is meant to provide a foundation for adding jumper wires dur-

ing the repair/modification process. The techniques and guidelines are based on

general commercial and industry practices.

Jumper wires fall into three (3) categories

1. Those that are considered wires and are installed during assembly. The routing,

termination, and bonding of these jumper wires are documented by engineering

instructions or drawing notations.

2. Those that are added after assembly to effect a change or modification. The

routing, termination, and bonding of these jumper wires are documented by engi-

neering change notice instructions or drawing notations.

3. Those that are added to correct a defect.

This procedure has nine main sections.

1. References

2. Tools and Materials

3. General Rules

4. PC Board Preparation

5. Jumper Wire Selection

6. Jumper Wire Preparation

7. Jumper Wire Termination and Routing

8. Jumper Wire Bonding

9. Jumper Wire Termination Figures

REFERENCES

1.0 Foreword

2.1 Handling Electronic Assemblies

2.2 Cleaning

2.5 Baking and Preheating

TOOLS & MATERIALS

Adhesive, Hot Melt

Adhesive, Quick Set

Cleaner

Cleaning Wipes

Flush Cutter

Flux, Liquid

Smooth Pliers

Solder

Soldering Iron with Tips

Tape Dots

Wire

Wire, Adhesive Coated

Wire Stripper

Figure 1 Route jumper wires.

Figure 2 Use sleeving through PTH.

Figure 3 Use insulated wire if

required.

Figure 4 Bond wires using tape dots

or strips.

7721A

Repair and

Modification of

Printed Boards and

Electronic Assemblies

Revision:

Date: 11/99

Jumper Wires

Number: 6.1

Product Class: R/F/W/C

Skill Level: Intermediate

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.

Page1of10

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

--``,``,-`-`,,`,,`,`,,`---

GENERAL RULES

1. Jumper wires should be placed on the component side of the assembly or

printed board unless otherwise specified.

2. Jumper wires shall be routed in an XY manner as directly as feasible, making as

few bends as possible. (See Figure 1.)

3. Jumper wires shall not be raised more than 3.2 mm [0.125 in] above the board

surface or not above components or leads in such a way that they will interfere

with PC board mounting.

4. Bare conductor jumper wires longer than 12.7 mm [0.50 in] shall not be used.

Bare conductor jumper wires shorter than 12.7 mm [0.50 in] shall not violate the

minimum electrical clearance.

NOTE

The 12.7 mm [0.50 in] dimension refers to the length between terminations.

5. Jumper wires may pass over lands provided sufficient slack is available so that

the wire can be moved away from the land for component replacement. Jumper

wires shall not pass over pads or vias used as test points.

6. Jumper wires shall not be routed under or over component leads or component

bodies. Contact with heat sinks must be avoided.

7. Jumper wires shall not pass through component foot prints unless the layout of

the assembly prohibits the routing in other areas.

8. Jumper wires shall have stress relief.

9. Jumper wires may be routed through plated through holes provided the wire is

insulated and insulation sleeving is placed in the hole. If a hole is needed, use

the following method. (See Figure 2.)

A. Drill a hole 0.25 mm [0.010 in] larger than the insulation diameter.

B. Inspect the hole for burs or exposed internal circuits.

C. Document the added hole on a control drawing.

NOTE

Be careful that the drilled hole does not interfere with surface and internal con-

ductors.

10. Jumper wires soldered into plated through holes must be discernible on the

opposite side.

11. Jumper wires soldered to lifted or clipped component leads may require insula-

tion to prevent shorting. (See Figure 3.)

12. Jumper wires may be terminated by a variety of methods. See illustrations.

PC BOARD PREPARATION

1. Clean the area.

NOTE

When wires are in place cleaning will often be more difficult.

2. Remove coating material or oxidization as necessary from the component leads,

pads, or conductors where wire terminations will be soldered. Clean the area.

Figure 5 Bond wires using adhesive.

Figure 6 Adhesive coated wires are

heat bonded.

IPC-7721A

Number: 6.1

Revision:

Date: 11/99

Subject: Jumper Wires

Page2of10

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

--``,``,-`-`,,`,,`,`,,`---