My thoughts are:
Solder splash on contacts are caused by poor process control/design and therefore should be defined as rework as with any other defect associated with process control/design. Repair should be used for defects that have been caused by defective parts.
Clive Ashmore
Global Process Manager, ASM
Mr. Ashmore is responsible for the Global Applied Process Engineering group for DEK. Clive specializes in all aspects of manufacturing engineering, with special emphasis on mass imaging technologies.
According to IPC-7711B/7721B Rework, Modification and Repair of Electronic Assemblies, the removal of solder from a gold contact finger constitutes a repair.
The definitions of the 2 classifications are as such:
Rework: The act of reprocessing non-complying articles, through the use of original or equivalent processing, in a manner that assures full compliance of the article with applicable drawings or specifications.
Repair: The act of restoring functional capability of defective article in a manner that does not assure compliance of the article with drawings or specifications.
Kevin Beattie
Quality Manager, Sunstone Circuits
Kevin is part of the Sunstone Management team. In his role as Quality Assurance Manager, Beattie’s 25+ year background in Printed Circuit Board manufacturing is a tremendous asset to the Sunstone team. In addition, he brings valuable experience from his previous roles in the following areas: process engineering, new process introductions, support of nearly every manufacturing process, and extensive knowledge of Continuous Improvement, ISO, IPC, and various other industry requirements.
It is all a question of definition. We define these activities as follows: REWORK -- an operation that is carried out to rectify a manufacturing fault or error such as a soldering defect, a missing, incorrect or malfunctioning component. It is performed on the shop floor and usually follows the Inspection and Test procedures which reveal a defect. REPAIR -- An operation carried out on an assembly that has passed all Inspection and QC tests, has been shipped and has subsequently failed "in the field". It is returned to the factory or a Repair Site where the repair is carried out. The actual procedures may be the same as Rework -- depending on the diagnosis of the fault -- but may also cover physical damage such as cracked PCB, broken traces, etc. As far as the Solder Splash is concerned -- take your pick!
Harold Hyman
Consultant, VJ Electronix
Harold Hyman has been involved in metallurgical aspects of the electronics industry since the 1950's, and in semiconductor development and engineering for STL, Ediswan & RCA. He later joined HTC, a pioneer of vapor phase soldering and continued industry experience Dynapert, GenRad, Teradyne, SRT and VJ Electronics.
Gold edge contact re-plating is considered to be a Repair, not a Rework, and is detailed as such in IPC 7711/7721 section 4.6.3 of the Repair section. The distinctions between "Repair" and "Rework" and "Modification" are also defined in IPC 7711/7721 section 1.4: - Modification The revision of the functional capability of a product in order to satisfy new acceptance criteria. Modifications are usually required to incorporate design changes which can be controlled by drawings, change orders, etc. Modifications should only be performed when specifically authorized and described in detail on controlled documentation.
- Rework The act of reprocessing non-complying articles, through the use of original or equivalent processing, in a manner that assures full compliance of the article with applicable drawings or specifications.
- Repair The act of restoring the functional capability of a defective article in a manner that precludes compliance of the article with applicable drawings or specifications.
October 2003 IPC-7711A/7721A Because you are replating using chemicals and methods not originally on the CCA BOM, you are not returning the CCA to full print compliance, so it is considered to be a Repair. It may be fully functional, but just does not comply with the original process and/or materials. Performance of Rework is generally considered to be acceptable without customer permission, but performance of Repair methods is usually more strictly controlled and the customer may allow them outright if as done per IPC 7711/7721, or may require pre-authorization by the customer, or may not allow them. It is important that this is defined clearly ahead of time within the contract, as agreed between User and Supplier (AABUS). Modifications are pre-approved changes documented by the customer and flowed down to the Supplier (usually) in the form of Engineering Change Notices (ECN). You should always discuss the ground rules with your customer or supplier as the case may be, and document it as part of the Contract.
Richard D. Stadem
Advanced Engineer/Scientist, General Dynamics
Richard D. Stadem is an advanced engineer/scientist for General Dynamics and is also a consulting engineer for other companies. He has 38 years of engineering experience having worked for Honeywell, ADC, Pemstar (now Benchmark), Analog Technologies, and General Dynamics.
In response to the second of your two questions, are there clear definitions for the terms repair and rework? Yes, IPC-7711/7721 Rev B section 1.4 Terms and Definitions provides clear distinction between Rework and Repair as follows: REWORK is the act of reprocessing noncomplying articles, through the use of original or equivalent processing, in a manner that assures full compliance of the article with applicable drawings or specifications. Whereas a REPAIR is the act of restoring the functional capability of a defective article in a manner that does not assure compliance of the article with applicable drawings or specifications. Now in response to your first question, we would define this process a Rework. We perform this rework on a regular basis. We are able to replate the gold fingers using an "equivalent processing" and we can measure the plating deposition thickness to "assures full compliance of the article with applicable drawings or specifications" as detailed in the IPC definition.
Peter Vigneau
Vice President, Circuit Technology Center
Mr. Vigneau has been a key member of the team at Circuit Technology Center since 2008. He has vast expertise, experience and understanding of complex circuit board rework, repair and modification operations. He is one of the most knowledgeable experts in this area across the globe.
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