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5.1 Plated Hole Repair, No Inner Layer Connection

 
Outline
This procedure covers repairing a damaged hole with no inner layer connection. An eyelet is used to repair the damage to the hole, and the eyelet flange replaces the lands on the circuit board surface.

Caution: This procedure is used only to restore the integrity of a through connection in a double-sided board or a multilayer board where there is no inner layer connection. If there is an inner layer connection, see the appropriate procedure.

Minimum Skill Level - Intermediate
Recommended for technicians with skills in basic soldering and component rework, but may be inexperienced in general repair/rework procedures.

Conformance Level - High
This procedure most closely duplicates the physical characteristics of the original, and most probably complies with all the functional, environmental and serviceability factors.

Acceptability References
IPC-A-600 2.0 Externally Observable Characteristics
IPC-A-600 3.0 Internally Observable Characteristics
Procedure References
1.0 Foreword
2.1 Handling Electronic Assemblies
2.2 Cleaning
IPC7721 5.1 Plated Hole Repair, No Inner Layer Connection
Kits and Systems
201-2100
Professional Repair Kit
Kit to repair circuit board damage including pads, lands, conductors, base material and plated holes.
110-5202
Eyelet Press
Heavy duty eyelet press designed to set and form eyelets in circuit boards.
201-3140
Plated Hole Repair Kit
Kit to repair damaged plated holes on circuit boards using eyelets.
201-4350
Repair Skills Practice Kit
Training kit to practice circuit board repair skills prior to testing for certification.
201-7100
Precision Tool Set
Nine precision-crafted tools for detailed circuit board work.
Tools and Materials
cutting
Ball Mills, Abrasives, Cutting Tools
Ball mills, abrasives and cutting tools for working on circuit boards.
235-2106-5
Cleaning Brushes
Disposable brushes for solvent cleaning and application of coatings.
eyelets
Eyelets
Copper and brass eyelets electroplated with tin designed for repair of plated through holes.
115-3115
Measuring Microscope Pen, 25X
Pocket pen microscope with 25X measuring reticle.
115-3120
Setting Tool, Small
Used to properly form eyelets used to repair plated holes in circuit boards.
115-3122
Tool Base
Support base for Setting Tool when forming eyelets for plated hole repair.
115-3145
Tool Grip, Small
Handy tool has vise jaws to grip small items.
Additional Items and Supplies
Cleaner
Cleaner
General purpose cleaner for removing contamination.
Microscope
Microscope
Precision microscope with stand and lighting for work and inspection.
Pin Gauges
Pin Gauges
Use to provide accurate measurements for thickness and hole diameters.
Solderinmg Iron
Soldering Iron
Properly maintained soldering iron and properly sized soldering iron tips.
Wipes
Wipes
Nonabrasive, low-linting wipes for cleanup.
Eyelets and Tooling
Eyelets are used to repair plated holes in circuit boards and also to create a conductive path through circuit boards for various applications. The eyelets listed below are manufactured from copper or brass and have bright tin plating.
Part No. Type Metal ID OD LUF FD Setting Tool
115-7206-25 Flat Copper .020" .030" .094" .046" 115-3120
115-7209-25 Flat Copper .020" .030" .120" .046" 115-3120
115-7306-25 Flat Brass .030" .040" .093" .060" 115-3120
115-7336-25 Flat Brass .033" .047" .093" .080" 115-3120
115-7339-25 Flat Copper .033" .047" .125" .080" 115-3120
115-7353-25 Flat Copper .035" .047" .062" .080" 115-3120
115-7366-25 Flat Copper .036" .046" .093" .076" 115-3120
115-7453-25 Flat Copper .045" .059" .062" .090" 115-3120
115-7456-25 Flat Copper .045" .059" .090" .090" 115-3120
115-7459-25 Flat Copper .045" .059" .125" .090" 115-3120
115-7576-25 Flat Copper .057" .067" .095" .111" 115-3126
115-7676-25 Flat Copper .067" .078" .097" .130" 115-3126
115-8736-25 Funnel Brass .073" .089" .093" .125" 115-3126
All dimensions in inches, +/- .003".
Images and Figures
5.1 Plated Hole Repair, No Inner Layer Connection
Damaged Plated Hole
5.1 Plated Hole Repair, No Inner Layer Connection
Figure 1: Drill out the hole using a Micro-Drill System or Tool Grip and ball mill.
5.1 Plated Hole Repair, No Inner Layer Connection
Figure 2: The eyelet flange can be used to secure a new circuit in place.

5.1 Plated Hole Repair, No Inner Layer Connection
Figure 3: Set the eyelet using an Eyelet Press or using a Tool Grip and Setting Tools.
5.1 Plated Hole Repair, No Inner Layer Connection
Figure 4: The small cone tip end of the lower Setting Tool faces up. The large cone end of the upper setting tool faces down.
5.1 Plated Hole Repair, No Inner Layer Connection
Figure 5: Flare the eyelet barrel using the flare end of the setting tool.

5.1 Plated Hole Repair, No Inner Layer Connection
Figure 6: Flatten the eyelet barrel using the flat end of the setting tool.
5.1 Plated Hole Repair, No Inner Layer Connection
Figure 7: Completed repair.
5.1 Plated Hole Repair, No Inner Layer Connection
Figure 8: Flat flange eyelet.

5.1 Plated Hole Repair, No Inner Layer Connection
Figure 9: Funnel flange eyelet.
Eyelet Selection Criteria

ID - Inside Diameter
The eyelet inside diameter should be .075 - .500 mm (.003"-.020") greater than the component lead diameter.

OD - Outside Diameter
The clearance hole drilled through the circuit board should allow the eyelet to be inserted without force but should not exceed .125 mm (.005") greater than the eyelet's outside diameter.

LUF - Length Under Flange
The length of the eyelet barrel under the flange should be .630 - .890 mm (.025" - 035"), greater than the thickness of the circuit board. This added length allows for proper protrusion when setting the eyelet.

FD - Flange Diameter
The eyelet flange diameter should be small enough to prevent interference with adjacent lands or circuits.

Note
Be sure to select an eyelet meeting the proper criteria. An eyelet with an oversize flange may interfere with adjacent circuits. An eyelet that is too short will not protrude through the circuit board for proper setting.

Procedure
  1. Clean the area.
  2. Select an eyelet using the Eyelet Selection Criteria. Use a pin gauge and caliper to measure the existing plated hole dimensions.
  3. Insert the appropriate ball mill into the Micro-Drill System or Tool Grip. Drill out the hole removing all the plating. The drilled hole should be .025 - .125 mm (.001" - .005") larger than the eyelet O.D. (See Figure 1)
    Caution: This procedure may isolate internal connections on multilayer circuit boards.
  4. Clean the area.
  5. Apply a small amount of liquid flux to the land or circuit on the circuit board surface, if any, and tin with solder using a soldering iron and solder. Clean the area.
  6. Insert the eyelet into the hole. If a new circuit is required, the new circuit may extend into the drilled hole, and the eyelet flange will secure the new circuit in place. (See Figure 2)
  7. Select the proper setting tools and insert them into the Eyelet Press System or Tool Grip and Tool Base. (See Figure 3)
  8. Turn the circuit board over and rest the eyelet flange on the lower setting tool. (See Figures 4 and 5)
  9. Apply firm, even pressure to flare the eyelet barrel. (See Figure 5)
  10. Change the upper setting tool from a flare tool to a flat-end tool. Apply firm, even pressure to flatten the eyelet barrel. (See Figure 6)
    Note: Inspect the eyelet for evidence of damage. Refer to IPC-A-610 Acceptability of Electronic Assemblies.
  11. Apply a small amount of liquid flux and solder the eyelet flanges to the lands on the circuit board surface if necessary. Clean the area. Inspect for good solder flow and wetting around the eyelet flanges and lands. (See Figure 7)
Evaluation
  1. Visual examination, the dimensional requirement of land diameter and inside diameter.
  2. Electrical continuity measurement.
Procedure for reference only.