Ask the Experts
April 15, 2019
Customer Approval for Repairs
We have a case where a non-aerospace customer's board was repaired without prior authorization. It was for a class 3 assembly. Does it specify in an IPC document that customer approval is required for class 3 repairs?
Expert Panel Responses
It may depend on the type of defect and the repair performed, whether or not the assemblies performance could be affected (things like jumper wires can play havoc on noise/emission sensitive PCBA's). It may not be possible to fully judge the impact of a repair on a PCBA unless you fully understand the design and the other components that will interface with that PCBA.
In the IPC A 610, revision F, it states in the forward section, 126.96.36.199 Defect Condition, paragraph 1: Defect Conditions SHALL be dispositioned by the manufacturer based on design, service, and customer requirements. Disposition may be to rework, repair, scrap, or use as is. Repair or "use as is" may require customer concurrence.
In a nutshell, it's really up to your customer, but it should be written into your contract either way. The Class of the PCBA should only help determine what the repair result should be.
Esterline Interface Technologies
Mr. Hughes has been in the electronics manufacturing field for 20 years. Operating the processes and as a manufacturing engineer for the last 14 years. He is also a CIT as well as an SMTA Certified Process Engineer.
Depending on the type of damage, as long as you meet class 3 requirements, you can make repairs. Regarding customer approval, that should be determined up front between the customer and supplier prior to manufacturing. There are some high reliability products.
That are built at IPC class 3 where rework or repair is not allowed. Again, this is determined by the customer's requirements.
Manufacturing Applications Specialist
Mr. Bush has 20 years experience in electronics contract manufacturing. Major areas of expertise include through hole, SMT, wave and selective soldering.
IPC7711 Section 1.7 establishes: When rework, repair, or modification of newly manufactured products is conducted, appropriate approvals may be required.Unless prohibited by the customer, rework of newly manufactured products may be performed without prior approval of the customer. Repair actions generally require prior approval by the customer. Modification may require prior approval of the customer.
Senior Manufacturing Engineer
Edithel is a chemical engineer with 20 year experience in manufacturing & process development for electronic contract manufacturers in US as well as some major OEM's. Involved in SMT, Reflow, Wave and other assembly operations entailing conformal coating and robotics.
Per the information provided in IPC J-STD-001 I submit the following:
J-STD-001 Paragraph 1.5.1 Hardware Defects and Process Indicators, states in the second paragraph that "...Defects shall [D1D2D3] be identified, documented and dispositioned by the Manufacturer-based on the design, service and customer requirements. Disposition is the determination of how defects are to be treated, and include, but are not limited to, rework, scrap, use-as-is, or repair."
Hence all process or product defects as defined in the J-STD-001 shall be identified and dispositioned per this requirement.
Paragraph 13.1 Rework, states "...hardware defects shall [N1N2D3] be documented before rework. Rework for Classes 1 or 2 should and for Class 3 shall [N1N2D3] be documented.:
Additionally it states in Paragraph 13.2 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. A hardware defect shall not [N1N2D3] be repaired until the discrepancy has been documented. The repair method shall [N1N2D3] be determined by agreement between the Manufacturer and the User."
Therefore to answer the question "Does it specify in an IPC document that customer approval is required for class 3 repairs?" the answer is yes per paragraph 13.2 Rework.
This is very similar to the MRB (Material Review Boards) who were involved in the disposition of rejected product, with the additional information of how the rework or repair is to be conducted and that information can come from the IPC-7711/7721 Rework, Modification and Repair of Electronic Assemblies.
Vice President, Technical Director
At EPTAC Corporation, Mr. Lambert oversees content of course offerings, IPC Certification programs and provides customers with expert consultation in electronics manufacturing, including RoHS/WEEE and lead free issues. Leo is also the IPC General Chairman for the Assembly/Joining Process Committee.
I do not think there is any IPC requirements that customer boards need customer approval prior to repair.It all depends on what type of contractual agreement is made with customer for repairs. Class 1,2 and 3 are more related to application and severity of use.
Astra Microwave Products, Hyderabad, AP India
Holds Degree in Engineering, started off as Scientist/Engineer in ISRO (Indian Space Research Organization) in Quality Assurance of Space hardware Electronics Production. Worked in the area of Parts, Material and Process; DPA, FA and Process Qualification for space and ground hardware. Later moved into Private sector and worked in the area of Quality Management Systems & ISO 9001 certification. Currently hold a position as Head-Quality in RF/Microwave Product manufacturing for Defense and Aerospace segment.
IPC does not directly dictate the number of times a repair can be conducted on a PCB. However depending on the type of repair and the type of processes used in your factory, You should not exceed 5 heat cycles on a PCB(This is the IPC Spec), i.e. SMT Bottom Manufacturing (1), SMT Top Manufacturing (2), Wave Solder Manufacturing (3), BGA change - Remove(4) and replace(5) equals 5 heat cycles.
Based on this info, if you are doing any repair with heated forced air convection, or infrared you will soon be at the limit of 5 heat cycles on your PCB. IF you are doing other repairs, example: changing of resistors or capacitor, then 3 repairs should be safe.
Based on your information provided, you are a class 3 manufacture and you are supplying for Aerospace. Your manufacturing facility be ISO TS16949 or AS9001. You should specify the number of attempts of repair that can be conducted on a product, in your Quality Management System Manual.
This will safe guard both, the customer and manufacture if there are any field failures, due to non-validated rework. I also recommend that you enforce repair validation to be conducted on your repaired product to prevent re occurrence.
Process Engineering Manager - Electronics
Altech UEC, South Africa
Currently with Altech UEC and responsible for technology road map in PCBA electronic manufacturing and technical support for PCBA electronic manufacturing for Altech UEC and its JDM's. Over 7 years in SMT, Radial Insertion, Wave solder & Test Applications.
As a general rule, the repair of an assembly requires customer's approval and rework does not regardless of the class of the product. However, the purchase order is the governing document to establish the contract requirements.
Engineering and Operations Management
Georgian Simion is an independent consultant with 20+ years in electronics manufacturing engineering and operations.
Contact me at firstname.lastname@example.org.
The experts have responded to the IPC impacts and requirements. My input comes from my experience in managing customers for EMS/Contract manufacturers. I'd say that a clearly defined Scope of Work is helpful in setting expectations from the customer side, if the customer's RFQ/RFP doesn't call out rework/repair specs. I agree that some customer purchase orders call out rework/repair specs, either in the PO body, or in the terms. Finally, a Manuf. Services Agreement, if used is a best practice. No matter whether this issue is clearly defined with the best of intentions, there will still be disputes.
Mark Edwards, Hisco Inc.