Circuit Board Repair Guide > Base Board Repair > 3.1 How to Repair Blisters in Circuit Board Base Materials

How to Repair Blisters in Circuit Board Base Materials

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 repair mechanical or thermal blisters or delaminations in circuit board laminated base materials. The blister is then sealed by injecting a low viscosity circuit board epoxy into the blister/delamination void.

This method can only be used when the laminate base material has separated sufficiently to allow the epoxy to flow throughout the void area.

IPC Acceptability References
IPC-A-610 2.0 Externally Observable Characteristics
IPC-A-600 10.0 Laminate Conditions
Delamination blister in base board needs repair

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
IPC7721 3.1 Delamination/Blister Repair, Injection Method

Tools and Materials
Alcohol Swabs - Self-saturating Isopropyl alcohol swabs. Squeeze handle to release alcohol.
Circuit Bond Pack - Clear, superior strength epoxy in two-compartment plastic package.
Microscope - It is a challenge to undertake precision repair without a good microscope.
Micro Drill System - Versatile power tool for milling, drilling, grinding, cutting and sanding circuit boards.
Ball Mills, Abrasives, Cutting Tools - Ball mills, abrasives and cutting tools for working on circuit boards.
Mixing Picks - Unique mixing sticks have a paddle shape on one and sharp pick on the opposite end.
Oven - General purpose oven for drying, baking and curing epoxies.
Syringes - Polypropylene syringe barrels with stainless steel dispensing tips.
Wipes - Nonabrasive, low-linting wipes for cleanup.

Drill into delamination blister

Fig. 1: Drill into the delamination blister using a ball mill and a
Micro Drill.

1.  Clean the area.
2.  Drill into delamination blister with the Micro Drill and ball mill. Drill in an area clear of circuitry or components. Drill at least two holes opposite each other around the perimeter of the delamination. (See Figure 1). Brush away all loose material.
Be careful not to drill too deep exposing internal circuits or planes.
Abrasion operations can generate electrostatic charges.
3.  Bake the circuit board to remove any entrapped moisture. Do not allow the circuit board to cool prior to injecting the epoxy.
Some components may be sensitive to high temperature.
Inject epoxy into delamination blister

Fig. 2: Inject epoxy into the delamination blister.

4.  Mix the epoxy. See manufacturers instructions on how to mix epoxy without bubbles.
Exercise care to prevent bubbles in the epoxy mixture.
5.  Pour the epoxy into the epoxy cartridge.
6.  Inject the epoxy into one of the holes in the delamination. (See Figure 2). The heat retained in the circuit board will improve the flow characteristics of the epoxy and will draw the epoxy into the void area filling it completely.
7.  If the void does not fill completely, the following procedures may be used:
  1. Apply light local pressure on the board surface starting at the fill hole, slowly proceeding to the vent hole.
  2. Apply vacuum to the vent hole to draw the epoxy through the void.
8.  Cure the epoxy per Procedure 2.7 Epoxy Mixing and Handling.
9.  Scrape away any excess epoxy using a knife or scraper.
If needed, apply additional thin coating to seal any scrapped areas.
Completed base board delamination repair

Fig. 3: Base board repair completed.

1.  Visual examination for texture and color match.
2.  Electrical tests to conductors around the repaired area as applicable.

Special Order. Usually ships within 3 business days from Haverhill, MA, USA.   For customer service call 1-519-651-3060.

How to purchase.                                                           View cart Minimum order $50 + shipping
Image Description Part No., Price and Quantity
Alcohol Swab Alcohol Swabs (package of 50), 235-1000-50

Self-saturating foam swabs filled with 99% Isopropyl alcohol. Ideal for removing flux residue and cleaning surfaces prior to soldering, coating and application of epoxy. Overall Length: 4.125". Squeeze handle until it "pops" releasing alcohol into the tip.


$39.00 pkg/50

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.


$12.95 each

Mixing Pick Mixing Picks (package of 100), 115-3315-100

Unique mixing sticks have a paddle shape on one end for mixing, and sharp pick on the opposite end.


$9.50 pkg/100

Syringes 115-3902 Syringes (package of 3), 115-3902

Polypropylene syringe barrels with 0.008" diameter stainless steel dispensing tips. Ideal for precise dispensing of epoxies and other liquids.


$7.95 pkg/3


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

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

Links to Related Products

Professional Repair Kit used to repair damaged circuit boards   Professional Repair Kit 201-2100
This circuit board repair kit includes everything needed for a wide range of circuit board repair needs. The Professional Repair Kit is designed to be used for the following applications: surface mount and BGA pad repair, circuit and land repair, plated hole repair, gold edge contact repair, solder mask and base board repair. This is the most popular circuit board repair kit we sell.

Micro Drill System used for drilling, grinding, cutting circuit boards   Micro Drill System 110-4105
The Micro Drill System is a repair technician's dream and is ideal for milling, drilling, grinding, cutting and sanding circuit boards. It removes coating, cuts circuits, cuts leads, drills holes, cuts slots, shapes FR4 and performs many other procedures using various interchangeable bits. Unlike most hand-held tools, the Micro Drill has a tiny, high speed DC motor in the hand piece, eliminating cumbersome drive cables and giving you better control. A separate power supply keeps the hand piece lightweight and reduces operator fatigue. Base unit has controls for forward/reverse and speed up to 45,000 RPM.

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