IPC-7711/7721 - Rework, Repair, and Modification of Electronic Assemblies

Introduction

The production of electronic devices (just like any other type of manufacturing) will, sooner or later, require the rework/repair of nonconforming products. Whether we like it or not, this is a common element of most manufacturing processes.

The correction of a nonconforming product is formally defined either as rework or as repair. These two terms have different meanings, so it's important to distinguish them correctly:

• Rework aims to restore full compliance with the product specification. After rework is completed, the product is "as good as new one" that didn't require any correction. Rework may require customer approval (is not mandatory).
• Repair aims to restore product functionality, but without full 100% compliance with the specification. In other words, the product will operate and function even if certain deviations for the spec remain. Repair always requires customer approval.

The IPC-7711/7721 standard also uses the term modification. This refers to situations where a conforming product is intentionally altered. These changes may involve fixing a design issue, changing the product version (upgrade/downgrade), converting to another variant, and so on.

I recommend to read the article: Rework, Repair or Modification, where we discuss these concepts in more detail in the context of IATF-16949 and IPC-7711/7721.

This article serves as an introduction to the IPC-7711/7721 standard, which covers rework, repair, and modification of assembled electronic modules. Enjoy the read!

History of IPC-7711/7721

The IPC-7711/7721 standard was developed by the Global Electronics Association (IPC) organization in 1998, based on the much older (now withdrawn) IPC-R-700 standard. Currently (as of November 2025), the latest version of IPC-7711/7721 is Revision "D", published in January 2024.

The revision / history of every IPC standard is published on the IPC website in the "Document Revision Table" section.[1]

Scope of IPC-7711/7721

The IPC-7711/7721 provides recommended procedures for performing rework, repair, and modification of assembled printed circuit boards (electronic modules, PCBAs). As the standard symbol/name suggests, it consists of two "smaller standards":

• IPC-7711 - includes procedures related to rework. Rework covers activities such as THT or SMD component replacement and solder bridge removal (shorts).
• IPC-7721 - includes procedures related to repair and modification. This includes tasks such as repairing PCB damage (traces, pads, plated holes, base material), adding additional components and jumper wires, and repairing wiring (splices).

It's also worth to note, that the IPC-7711/7721 standard does not limit the maximum number of rework or repair operations performed on a single assembled board.

IPC-7711/7721 main sections

The IPC-7711/7721 standard provides recommendations for rework, repair, and modification of assembled electronic boards in the following sections:[2]

• General Principles. This is the first section of the standard, covering topics such as the scope and purpose of the document, terminology and definitions, IPC product classes, as well as recommendations regarding the materials used, including soldering flux, SMT solder paste, lead-based alloys, lead-free alloys, adhesives, and other materials. This section also discusses tools, different heating methods, level of conformance, and personnel skill requirements.
• Common Procedures:
  • Cleaning. Cleaning the PCB of flux residues and other contaminants. Maintaining proper cleanliness levels is critical for reliability and helps reduce the risk of electrochemical migration (dendrites).
  • Coating Removal. This section provides procedures for identifying the type of protective coating (conformal coating) and describes various removal methods—from mechanical scraping, to chemical processes, to micro-abrasive blasting.
  • Coating Replacement. Replacement of solder mask layers and application of new protective layers.
  • Conditioning. Laminates and components can absorb moisture. Therefore, it is important to properly handle moisture-sensitive level (MSL) devices and reduce PCB moisture content.
  • Mixing and Applying Epoxy Resins. Recommendations for handling two-component epoxies used in certain repair procedures (IPC-7721).
  • Legend/Marking Repair. Restoring missing PCB markings using three methods: stamping, hand lettering, or stencil printing.
  • Tip Care and Maintenance. An additional but very important procedure describing how to properly maintain a soldering iron tip to keep it in good condition and extend its service life.
• Applicable Documents. A list of other standards related to IPC-7711/7721, developed by IPC, J-STD, ASTM, ESDA, and military standards (MIL-STD).
• Rework. This section corresponds directly to IPC-7711 and includes procedures such as:
  • THT desoldering (THT and PGA components).
  • Removal of SMD components (various package types: chip, SOT, QFP, BGA, etc.).
  • Preparation of solder pads (removal of solder residues, cleaning).
  • Assembly and soldering of THT components (according to J-STD-001 requirements).
  • Assembly and soldering of SMD components (various package types).
  • Removing shorts (sholder bridges).
• Repair and Modification. This section corresponds to IPC-7721 and includes advanced repair procedures such as:
  • Removal of blisters and delamination.
  • Bow and twist repair.
  • Repair of damaged holes.
  • Repair of PCB key/slots.
  • Repair of base material (e.g., laminate burns).
  • Repair of lifted conductors (pads or traces).
  • Repair of damaged conductors (trace cuts, etc.).
  • Repair of edge connectors.
  • Repair of SMD pads.
  • Repair of plated-through holes.
  • Jumper wires.
  • Installation of additional components.
  • Repair of flexible conductors.
  • Repair of wires, commonly referred to as splices.

Level of Conformance

Each rework/repair procedure is assigned a specific "level”, which indicates how closely the result of that rework or repair matches the original product's quality (and therefore its reliability). There are three defined conformance levels:

• L (Lowest Level). The lowest level. Significant differences from the original may be present. As a result, changes in performance and reliability may occur due to environmental, electrical, or later servicing factors.
• M (Medium Level). The medium level. Generally reproduces most characteristics of the original. Some changes in performance or reliability may occur under environmental, electrical, or servicing factors.
• H (Highest Level). The highest level. Most closely resembles the original and is expected to perform just like the original, even under variations in environmental, electrical, or service-related factors.

For electronics built to IPC Class 3, only the highest conformance level (H) must be used. Lower levels may be applied only if it can be confirmed that they will not negatively affect product performance (or reliability).

For Class 2 and Class 1 products, using the highest conformance level (H) is also strongly recommended.

In summary: The conformance level tells us whether a given rework/repair/modification method provides the highest possible level of quality and reliability (H), a medium level (M), or something… well, not great (L).

Skill Level

Replacing electronic components, removing and reapplying conformal coating, and performing advanced laminate repairs require focus, patience, precision, and strong manual skills. Some tasks are relatively easy (e.g., soldering simple THT parts), while others are extremely challenging (e.g., replacing BGA packages). For this reason, the IPC-7711/7721 standard defines a required skill level for each procedure. The following levels are specified:

• Intermediate (I). The lowest level. The operator has basic soldering/assembly knowledge but lacks experience with most procedures. In short… they're still learning :)
• Advanced (A). The operator handles things pretty well ;) They know most procedures but are still building deeper experience.
• Expert (E). The highest level. Extensive knowledge, strong experience, and excellent manual skills. Can remove PGA connectors, assemble QFNs, repair flexible circuits (flex), and more.

Summary

Performing rework, repair, or modification on assembled electronic boards requires proper manual skill and knowledge of soldering process, solder joint quality requirements. It is also very important to have proper soldering equipment, a microscope, and high-quality materials (flux, solder alloy, adhesives, etc.).

Another critical factor is the method used to carry out the rework/repair/modification. Not every approach to component removal, soldering will deliver high quality/reliability. That's why the electronics industry strongly recommends the proven procedures from IPC-7711 (rework) and IPC-7721 (repair and modification).

Applying these guidelines ensures that the work performed aligns with internationally recognized standard and helps to minimize the risk of field failures or other quality issues.