Circuit Board Repair Guide > Plated Hole Repair > 5.2 Plated Hole Repair, Double Wall Method

Plated Hole Repair, Double Wall Method

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 use of an eyelet for the repair of a damaged land on a hole that has an inner layer connect.

Caution
This procedure is used to restore the integrity of a through connection on a multilayer circuit board, having an inner layer connect, but ONLY if the full barrel of the plated through hole remains intact. If there is barrel damage see appropriate procedure.

Caution
This procedure will reduce the inside diameter of the hole. The minimum hole size requirement must be checked for acceptance.
 
Damaged plated hole with inner layer connection needs repair
Damaged Plated Hole with
Inner Layer Connection

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
IPC7721 5.2 Plated Hole Repair, Double Wall Method

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

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.
 

5.2 Plated Hole Repair, Double Wall Method

Printed Board Type: R/F/W  |  Skill Level: Advanced  |  Conformance Level: Medium  |  Rev.: F  |  Rev. Date: Mar 28, 2001

Insert eyelet into hole.

Fig. 1: Insert eyelet into the hole.


1. 
Clean the area.
 
2. 
Examine the hole to ensure that there is no damage to the wall of the hole. Check continuity to establish the integrity of the connection.
   
3. 
Select an eyelet using the Eyelet Selection Criteria. Use a pin gauge and caliper to measure the existing plated hole dimensions. The eyelet must have an inside diameter sufficient to receive the component lead and an outside diameter that will allow the eyelet to be inserted into the hole without force.
 
4. 
Remove oxides from the surface lands where the eyelet is to be installed using a buffer and clean.
   
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 hole and the flange of the eyelet will secure the new circuit in place. (See Figure 1).
 
Circuit board eyelet press

Fig. 2: Set the eyelet using an
Eyelet Press.


7. Select the proper setting tools and insert them into the eyelet press. (See Figure 2).
   
8. Turn the circuit board over and rest the eyelet flange on the lower setting tool.
   
9. Apply firm even pressure to form the eyelet barrel.
   
10.
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.
   
11. Clean the area.
   
12. Install the component lead and solder, if required.

Plated hole repair completed

Fig. 3: Plated hole repair completed.
Evaluation
   
1.  Visual examination, dimensional requirement of land diameter and inside diameter.
   
2.  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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