12 / SERVICE · Rework

Rework PCB — precise repair and component replacement per IPC 7711/7721

Rework is the process of repairing or modifying an assembled PCB: replacing damaged or faulty components, correcting soldering defects, removing and re-soldering BGA packages. We carry out rework as per the IPC 7711/7721 standard — with full documentation of every repair and quality verification after the process.

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IPC
7711/7721
BGA
QFN · QFP · LGA
AOI
3D + X-Ray

What is PCB rework and when is it needed?

Rework is the repair or modification of a PCB after assembly — as opposed to production from scratch. The need for rework arises in several situations: a component defect detected after a functional test, an assembly error requiring correction, a design change requiring component replacement (ECO), or repair of a device returned from service.

Unlike series assembly on the line, rework requires precise, controlled, point intervention — removing one component without damaging neighbouring elements and the board, then re-mounting it with the same solder joint quality as in factory assembly.

The IPC 7711/7721 standard defines the permissible methods, thermal parameters and acceptance criteria for rework — it is what distinguishes professional repair from a makeshift soldering iron intervention.

Soldering and rework methods at Siltegro

01

BGA replacement

Removing and re-mounting BGA (Ball Grid Array) components — a process requiring controlled heating, removal of old solder balls, preparation of the solder field and precise placement of the new component. Joint quality verified by X-Ray inspection after rework.

02

SMD soldering

Manual and selective soldering of surface-mount components during rework — replacing resistors, capacitors, QFN chips and other SMD components without damaging neighbouring solder fields.

03

THT soldering

Replacement of through-hole components during rework: connectors, transformers, power elements. Precise desoldering without overheating the laminate and neighbouring traces.

04

Automatic soldering for series repairs

For rework covering a larger number of identical boards — e.g. correcting an error detected across a whole batch — we use automated soldering stations ensuring repeatability of the correction regardless of the number of units.

05

Repair of assembly defects

Correction of solder bridges, cold joints and component misalignment detected during AOI or X-Ray inspection — repair without restarting the whole batch.

When is rework the right solution?

Defect detected after a functional test

If a single board or batch fails a test because of one faulty component — rework lets you fix the problem without scrapping the whole board.

Design change requiring component replacement (ECO)

When the project documentation changes after production starts — rework implements the change on already-assembled boards instead of waiting for a new series.

Pilot batch update after field tests

If the first production batch passed internal or target-condition tests but needs a correction before the full series launch — rework lets you implement the change for the existing batch without repeating the entire assembly.

Correction detected during X-Ray or AOI inspection

When inspection reveals a problem with a specific solder joint — a point repair is faster and cheaper than re-assembly.

IPC 7711/7721 — the technical standard of rework

IPC 7711/7721 is the international standard defining the permissible repair and modification procedures for electronic assemblies. It covers, among others, the permissible thermal profiles when removing and mounting components, the joint quality acceptance criteria after rework, and the requirements for PCB surface preparation after component removal.

Carrying out rework as per IPC 7711/7721 means that every repair is documented, repeatable and verifiable — not an ad hoc intervention, but a controlled technical process.

What sets us apart in rework PCB?

X-Ray inspection after rework

Verification of BGA joint quality after replacement using radiographic inspection — confirmation that the new joint meets the same standards as factory assembly.

Rework as a documented process

Every repair is recorded as per the Siltegro traceability system — batch number, description of the correction performed, verification result after rework.

Team with factory assembly experience

Rework is performed by operators who know the SMT and THT assembly process from the ground up — they understand not only how to repair a joint, but why the defect occurred.

Technical parameters

StandardIPC 7711/7721
Component scopeBGA, QFN, SMD, THT
Soldering methodsManual, selective, automatic
Verification after reworkX-Ray inspection, AOI, functional tests
DocumentationFull repair record in the traceability system
Contact time24 hours

What to prepare for a rework request?

01

Problem description

Which component requires replacement or which defect was detected

02

Board documentation

Schematic, BOM or project number if the board was produced by Siltegro

03

Number of units

A single repair or a whole-batch correction

04

Deadline

Whether rework is urgent (return repair) or planned (ECO implementation)