Circuit Board Repair Guide > Conductor Repair Procedures > 4.5.2 How to Repair Damaged Lands Using Replacement Lands and Film Adhesive

How to Repair Damaged Lands Using Replacement Lands & Film Adhesive

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 procedure is used to replace damaged and lifted lands. The damaged lands are replaced with new dry film, adhesive backed lands. The new lands are bonded to the printed circuit board surface using a circuit bonding system or bonding iron.

Caution
This method is used to replace a damaged or missing land, but the new land will not have an intermetallic connection to the remaining plated hole. The solder joint of the replaced component will restore the integrity of the electrical connection.
 
Damaged land needs replacement
Damaged Land
Caution
It is essential that the board surface be smooth and flat. If the base board is damaged see appropriate procedure

Note
This method uses new lands that are fabricated from copper foil and have a dry film adhesive coating on the back. They are available in hundreds of sizes and shapes and are generally supplied solder plated. If a special size or shape is needed it can be custom fabricated.

IPC Acceptability References
IPC-A-600 2.0 Externally Observable Characteristics
IPC-A-610 10.0 Laminate Conditions
 
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
CTC 2.5 Baking and Preheating of Printed Circuit Boards
CTC 2.7 Epoxy Mixing and Handling
IPC 7721 4.5.2 Land Repair, Film Adhesive Method

Tools and Materials
Bonding Iron, 120 VAC - Delivers the optimal heat for curing adhesive bonding film.  Bonding Tips sold separately.
Bonding Tips - Used to cure adhesive backed circuit frames for pad, land and contact repair.
Circuit Bonding System  (optional) - System for applying heat and pressure to cure adhesive bonding film.
Circuit Frames, Lands - Replacement circuits with a dry-film adhesive backing for conductor repair.
Circuit Bond Pack - Clear, superior strength epoxy in two-compartment plastic package.
Cleaner - General purpose cleaner for removing contamination.
High Temperature Tape Discs - High temperature polyimide tape discs, .50" diameter.
Knife with #16 Blades - A must-have tool for precise cutting, scraping and trimming.
Microscope - It is a challenge to undertake precision repair without a good microscope.
Scraper - Hardened stainless steel tip for scraping solder mask and removing defects.
Soldering Iron, Solder and Flux - A well maintained soldering iron is a must at every tech bench.
Tweezer, Point Tip - Fine point tweezers for precision work.
Wipes - Nonabrasive, low-linting wipes for cleanup.

4.5.2 Land Repair, Film Adhesive Method

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

Repair defective land and remove solder mask

Figure 1: Remove the defective
land and remove solder mask
from the connecting circuit.

1.  Clean the area.
 
2. Remove the defective land and a short length of the connecting circuit if any.
(See Figure 1).
 
3. Use the knife and scrape off any epoxy residue, contamination or burned material from the board surface.

Caution
Abrasion operations can generate electrostatic charges.
 
4.  Scrape off any solder mask or coating from the connecting circuit. (See Figure 1).
 
5. Clean the area.
 
6. Apply a small amount of liquid flux to the connection area on the board surface and tin with solder. Clean the area. The length of the overlap solder connection should be a minimum of 2 times the circuit width.
 
Select replacement land that matches missing land

Figure 2: Select a replacement
land that matches the missing
land.


7. The area for the new land on the board surface must be smooth and flat. If internal fibers of the board are exposed or if there are deep scratches in the surface they should be repaired. Refer to appropriate procedure.
 
8.  Select a replacement land that most closely matches the land to be replaced from the Land Circuit Frames shown below. (See Figure 2).

Note
The new replacement land may be trimmed from copper sheet.
Scrape off adhesive on back of new land

Figure 3: Scrape off the adhesive bonding film from solder joint area
on the back of new land.


9.  Before trimming out the new land carefully scrape off the adhesive film from the solder joint connection area on the back of the new land. (See Figure 3).

Caution
Scrape off the epoxy backing only from the joint connection area. When handling the replacement land avoid touching the adhesive backing with your fingers or other materials that may contaminate the surface and reduce the bond strength.
Cut out new land

Figure 4: Cut out the new land.
Cut from the plated side.


10. Cut out and trim the new land. Cut out from the plated side. Cut the length to provide the maximum allowable circuit overlap for soldering. Minimum 2 times the circuit width. (See Figure 4).
Place new land

Figure 5: Place the new land in
place using High Temperature
Tape.


11. Place a piece of High Temperature Tape over the top surface of the new land. Place the new land into position on the circuit board surface using the tape to aid in alignment. (See Figure 5).
 
12. Select a bonding tip with a shape to match the shape of the new land. See bonding tip chart below.

Note
The Bonding Tip should be as small as possible but should completely cover the entire surface of the new land.
Bond new land with a Bonding System

Figure 6: Bond the new land with
a Circuit Bonding System or
Bonding Iron with the appropriate
Bonding Tip.

13. Position the circuit board so that it is flat and stable. Gently place the hot bonding tip onto the tape covering the new land. Apply pressure as recommended in the manual of the repair system or repair kit for 5 seconds to tack the land in place. Carefully peel off the tape. (See Figure 6).

Caution
Excessive bonding pressure may cause measling in the circuit board surface or may cause the new circuit to slide out of position.
 
14. Gently place the bonding tip directly onto the land. Apply pressure as recommended in the manual of the repair system or circuit board repair kit for an additional 30 seconds to fully bond the land. The bonding film is fully cured. After the bonding cycle remove the tape used for alignment. Carefully clean the area and inspect the land.
 
Land repair completed

Figure 7: Land repair completed.
15. If the new land has a connecting circuit apply a small amount of liquid flux to the lap solder joint connection area and solder the circuit from the new land to the circuit on the circuit board surface. Use minimal flux and solder to ensure a reliable connection. High Temperature Tape may be placed over the top of the new land to prevent excess solder overflow.

Note
If the configuration permits, the overlap solder joint connection should be a minimum of 3.00 mm (0.125") from the related termination. This gap will minimize the possibility of simultaneous reflow during soldering operations. Refer to 7.1 Soldering Basics.
 
16. Remove the tape and clean the area.
 
17. Mix epoxy and coat the lap solder joint connections. Cure the epoxy per Procedure 2.7 Epoxy Mixing and Handling.

Note
Additional liquid circuit board epoxy can be applied around the perimeter of the new land to provide additional bond strength.

Caution
Some components may be sensitive to high temperature.
 
18. Carefully remove any excess bonding film inside the plated hole using ball mill or drill bit. Turn the ball mill or drill bit by hand to prevent damage to the wall of the plated through hole.
 
19. Install the proper component and solder in place.

Note
This method is used to replace a damaged or missing land, but the new land will not have an intermetallic connection to the remaining plated hole. The solder joint of the replaced component will restore the integrity of the electrical connection or an eyelet or buss wire may be used. See Plated Hole Repair Procedures.
 
20. Apply surface coating to match prior coating as required.
 
  Evaluation
 
1.  Visual examination.
 
2.  Measurement of new land width and spacing.
 
3.  Electrical continuity measurement.
 

Circuit Frame Material Specifications

Overall Frame Size: 2.25" x 1.50" (57 mm x 38 mm)
Base Material: Rolled annealed copper foil .0014" (.036 mm) thick.
Adhesive Backing: B-staged modified acrylic film adhesive .002" (.051 mm) thick.
Bonding Temperature: 475°F +/- 25°F (246°C +/- 14°C)
Bonding Time: 30 seconds
Peel Strength: Minimum 8 lbs/inch (1.43 kg/cm) after cure to FR-4 material.
Shelf Life: 1 year minimum. Each Circuit Frame package is stamped with the expiration date.
Shelf-Life items may not be returned for credit.
Plating Option - Bright Tin:     .0001" (.0025 mm) Bright Tin (Lead Free)


Special Order. Ship within 3 business days. How to purchase.

Land Circuit Frames                    Minimum order requirement $50 plus shipping.

Image Description                                                            View cart Part Number
CP050060AS Lands .050"/.060" Circuit Frame CP050060AS

Lands .050"/.060" (1.27mm/1.52mm)

Plating: Bright Tin

Enlarge        Recommended Bonding Tip: 115-2202
CP050060AS

US $44.00

 
CP067267AS Lands .067" x .267" Circuit Frame CP067267AS

Lands .067" x .267" (1.70mm x 6.78mm)

Plating: Bright Tin

Enlarge
CP067267AS

US $44.00

 
CP070080AS Lands .070"/.080" Circuit Frame CP070080AS

Lands .070"/.080" (1.78mm/2.03mm)

Plating: Bright Tin

Enlarge        Recommended Bonding Tip: 115-2204
CP070080AS

US $44.00

 
CP090100AS Lands .090"/.100" diameter Circuit Frame CP090100AS

Lands .090"/.100" (2.286mm/2.540mm) Diameter

Plating: Bright Tin

Enlarge        Recommended Bonding Tip: 115-2206
CP090100AS

US $44.00

 
CP090100BS Lands 0.090" x 0.100" Circuit Frame CP090100BS

Lands .090" x .100" (2.286mm x 2.540mm)

Plating: Bright Tin

Enlarge        Recommended Bonding Tip: 115-2206
CP090100BS

US $44.00

 
CP140210AS Lands .140"ID x .210"OD Circuit Frame CP140210AS

Lands .210" (5.334mm) Diameter

Plating: Bright Tin

Enlarge
CP140210AS

US $44.00

 
CP156097AS Lands .156"OD x .097"ID Circuit Frame CP156097AS

Lands .156" (3.962mm) Diameter

Plating: Bright Tin

Enlarge
CP156097AS

US $44.00

 
CP250125AS Lands .250"OD x .125"ID Circuit Frame CP250125AS

Lands .250" (6.350mm) Diameter

Plating: Bright Tin

Enlarge
CP250125AS

US $44.00

 
Liquid circuit board epoxy Circuit Bond Pack  MSDS, 115-3302

Clear, low viscosity, superior strength epoxy, precisely measured out into a two-compartment plastic package so it's easy to use and there's no measuring (2 gram). Shelf life: 6 months minimum.

Enlarge
115-3302

$12.95 each

 
High Temperature Tape Discs 235-3050 High Temperature Tape Discs, .50" Diameter, 235-3050

High temperature tape discs are made of polyimide film with 1.5 mil of silicone adhesive that will not leave any residue. They can withstand temperatures of up to 500°F (260°C).
235-3050

US $5.95 pkg/60

 
Knife 355-0614 Knife with #16 Blades, 355-0614

A must-have tool for precise cutting, scraping and trimming. Includes five #16 blades.


Enlarge
355-0614

$9.95 each

 
Scraper 335-3197 Scraper, 335-3197

Hardened stainless steel tip for scraping solder mask and removing defects.



Enlarge
335-3197

$9.95 each

 
Tweezer, Point Tip 335-5185 Tweezer, Point Tip, 335-5185

Fine point tweezers are perfect for precision work.



Enlarge
335-5185

$9.95 each

 

Products above ship direct from manufacturer and are special order/non-returnable. Will ship within 3 business days.



 
Bonding Iron and Bonding Tips

Bonding Tips fit into the hand held Bonding Iron (part no. 115-3102 for 120 VAC and part no. 115-3103 for 230 VAC) and the Circuit Bonding System (part no. 115-3118 which includes voltage converter for 120 VAC and 220 VAC). The bottom machined surface of each Bonding Tip is used to apply heat and pressure to bond the adhesive backed replacement pads, edge contacts, and lands to the circuit board surface. All our Bonding Tips are machined from high grade aluminum.

Image Description                                                            View cart Part Number
Bonding Iron 115-3102 Bonding Iron, 120 VAC, 115-3102

The Bonding Iron is set at the optimal temperature for curing the bonding film used to repair damaged surface mount pads, lands, edge contacts and other circuit board patterns. Bonding Tip is not included with purchase of Bonding Iron so remember to also select and purchase a Bonding Tip to match the shape of the new pad or circuit. Enlarge

115-3102

US $109.00

 
Bonding Iron 115-3103 Bonding Iron, 230 VAC, 115-3103

The Bonding Iron is set at the optimal temperature for curing the bonding film used to repair damaged surface mount pads, lands, edge contacts and other circuit board patterns. Bonding Tip is not included with purchase of Bonding Iron so remember to also select and purchase a Bonding Tip to match the shape of the new pad or circuit. Enlarge

115-3103

US $179.00

 

115-2104 Tapered Tip
Bonding Tip 115-2104

Tapered



115-2104

US $45.00

 

115-2201 Circular Tip .025"
Bonding Tip 115-2201

.025" (.635mm) Diameter

Circular

115-2201

US $45.00

 

115-2202 Circular Tip .060"
Bonding Tip 115-2202

.060" (1.52mm) Diameter

Circular

115-2202

US $45.00

 

115-2204 Circular Tip .080"
Bonding Tip 115-2204

.080" (2.03mm) Diameter

Circular

115-2204

US $45.00

 

115-2205 Circular Tip .035"
Bonding Tip 115-2205

.035" (.89mm) Diameter

Circular

115-2205

US $45.00

 

115-2206 Circular Tip .120"
Bonding Tip 115-2206

.120" (3.05mm) Diameter

Circular

115-2206

US $45.00

 

115-2301 Small Rectangle Tip .010" x .080"
Bonding Tip 115-2301

.010" x .080" (.25mm x 2.03mm)

Small Rectangle

115-2301

US $45.00

 

115-2306 Small Rectangle Tip .040" x .060"
Bonding Tip 115-2306

.040" x .060" (1.02mm x 1.52mm)

Small Rectangle

115-2306

US $45.00

 

115-2308 Small Rectangle Tip .045" x .110"
Bonding Tip 115-2308

.045" x .110" (1.14mm x 2.79mm)

Small Rectangle

115-2308

US $45.00

 

115-2310 Small Rectangle Tip .050" x .050"
Bonding Tip 115-2310

.050" x .050" (1.27mm x 1.27mm)

Small

115-2310

US $45.00

 

115-2312 Small Rectangle Tip .060" x .080"
Bonding Tip 115-2312

.060" x .080" (1.52mm x 2.03mm)

Small Rectangle

115-2312

US $45.00

 

115-2316 Small Rectangle Tip .080" x .120"
Bonding Tip 115-2316

.080" x .120" (2.03mm x 3.05mm)

Small Rectangle

115-2316

US $45.00

 

115-2318 Large Rectangle Tip .080" x .500"
Bonding Tip 115-2318

.080" x .500" (2.03mm x 12.70mm)

Large Rectangle

115-2318

US $45.00

 

115-2320 Small Rectangle Tip .095" x 095"
Bonding Tip 115-2320

.095" x .095" (2.41mm x 2.41mm)

Small

115-2320

US $45.00

 

115-2322 Large Rectangle Tip .120" x .500"
Bonding Tip 115-2322

.120" x .500" (3.05mm x 12.70mm)

Large Rectangle

115-2322

US $45.00

 

Products above ship direct from manufacturer and are special order/non-returnable. Will ship within 3 business days.



Import duties and Value Added Tax will be collected at time of delivery for all shipments outside the USA.

2CheckOut.com Inc. is a payment facilitator for goods provided by ELAB (Engineering Lab). View cart

Payment methods accepted: American Express, Visa, MasterCard, Discover, Diners Club, JCB and Paypal.

Depending on issuing bank, charges on credit card statements should appear as 2CO.COM*ELAB.

If you use Paypal, your credit card statement will show Paypal*2CheckoutCO as the merchant.



Links to Related Products


Circuit Frames used to replace pads, lands and conductors   Circuit Frames
Circuit Frames allow you to replace damaged surface mount pads, lands and conductors without the mess of liquid epoxy, with a bond strength equal to the original, in just a few minutes. Circuit Frames come in a wide variety of shapes and sizes, all with a dry-film adhesive backing, activated and cured with heat and pressure. Trim out the circuit you need and bond it to the circuit board surface using a Bonding Iron or Circuit Bonding System with the appropriate Bonding Tip.



Copyright and Disclaimer Notice Copyright CircuitMedic, Haverhill, MA 01835 USA

Related Items
Conductor Repair | Prototyping Boards | Surface Mount Resistor Kits | Surface Mount Capacitor Kits | SMT Component Storage