Circuit Board Repair Guide > Plated Hole Repair > 5.1 Plated Hole Repair, No Inner Layer Connection

Plated Hole Repair, No Inner Layer Connection

Repair Circuit Boards | Repair SMT Pads | Repair BGA Pads | Repair Lands | Repair Edge Contacts
Repair a Conductor | Plated Hole Repair | Base Board Repair | Replace Solder Mask or Coatings

This plated hole repair procedure covers the repair of a damaged hole that has no inner layer connection. An eyelet is used to repair the damage to the hole and the eyelet flanges replace the lands on the printed circuit board surface.

This method 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 appropriate procedure.

Damaged plated hole needs repair
Damaged Plated Hole
IPC Acceptability References
IPC-A-600 2.0 Externally Observable Characteristics
IPC-A-600 3.0 Internally Observable Characteristics
Related Procedure References
CTC 1.0 Foreword - Circuit Board Repair Guide
CTC 2.1 Handling Electronic Assemblies
CTC 2.2.1 How to Clean a Circuit Board
CTC 2.2.2 Cleaning Circuit Boards, Aqueous Batch Process
IPC 7721 5.1 Plated Hole Repair, No Inner Layer Connection

Tools and Materials
Ball Mills
Caliper Gauges      
Eyelet Press
Eyelets, Various Sizes      
Flux, Liquid
Micro Drill System
Pin Gauges
Setting Form Tool, Various Sizes      
Setting Anvil, Various Sizes      
Soldering Station      

Eyelet Selection Criteria

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

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 outside diameter.

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.

5.1 Plated Hole Repair, No Inner Layer Connection

Printed Board Type: R/F/W  |  Skill Level: Intermediate  |  Conformance Level: High  |  Rev.: E  |  Rev. Date: Mar 28, 2001

Drill out hole using Micro Drill System

Fig. 1: Drill out the hole using a
Micro Drill System and ball mill.

Clean the area.
Select an eyelet using the Eyelet Selection Criteria. Use a pin gauge and caliper to measure the existing plated hole dimensions.
Insert the appropriate ball mill into the Micro Drill System. 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).

This procedure may isolate internal connections on multilayer circuit boards.
Eyelet flange used to secure new circuit

Fig. 2: The eyelet flange can be used
to secure a new circuit in place.

Clean the area.
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.
Insert the eyelet into the hole. If a new circuit is required, the new circuit may extend into the drilled hole and the flange of the eyelet will secure the new circuit in place. (See Figure 2).
Circuit board eyelet press

Fig. 3: Set the eyelet using an
Eyelet Press.

Select the proper setting tools and insert them into an eyelet press system. (See
Figure 3).
Turn the circuit board over and rest the eyelet flange on the lower setting tool.
Apply firm even pressure to form the eyelet barrel.

Inspect the eyelet flange for evidence of damage. Refer to IPC-A-610 Acceptability of Electronic Assemblies.
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.
Plated hole repair completed

Fig. 4: Plated hole repair completed.
Visual examination, dimensional requirement of land diameter and inside diameter.
Electrical continuity measurement.

Links to Related Products

Circuit board eyelet press 110-5202  
Circuit Board Eyelet Press 110-5202
Rugged, heavy duty circuit board eyelet press precisely forms eyelets in circuit boards for repair or assembly. Eyelet press has 6.5" throat depth to accommodate 12" wide circuit boards. This eyelet press will deliver years of maintenance-free reliable production.

Plated Hole Repair Kit used to repair damaged plated through holes  
Plated Hole Repair Kit 201-3140
Plated Hole Repair Kit includes all the tools and materials you'll need to repair damaged plated through holes in circuit boards. This circuit board repair kit includes a variety of eyelet sizes, carbide ball mills for drilling, and setting tools to form the eyelets conforming to IPC guidelines.

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