Ask the Experts
January 24, 2018
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
Itmay depend on the type of defect and the repair performed, whether or not theassemblies performance could be affected (things like jumper wires can playhavoc on noise/emission sensitive PCBA's). It may not be possible to fullyjudge the impact of a repair on a PCBA unless you fully understand the designand the other components that will interface with that PCBA.
Inthe IPC A 610, revision F, it states in the forward section, 188.8.131.52 DefectCondition, paragraph 1: Defect Conditions SHALL be dispositionedby the manufacturer based on design, service, and customer requirements.Disposition may be to rework, repair, scrap, or use as is. Repair or "use asis" may require customer concurrence.
Ina nutshell, it's really up to your customer, but it should be written into yourcontract either way. The Class of the PCBA should only help determine what therepair 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 newlymanufactured products is conducted, appropriate approvals may be required.Unless prohibited by the customer, rework of newly manufactured products may beperformed without prior approval of the customer. Repair actions generallyrequire prior approval by the customer. Modification may require prior approvalof 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.
Perthe information provided in IPC J-STD-001 I submit the following:
J-STD-001 Paragraph 1.5.1 Hardware Defects and ProcessIndicators, states in the second paragraph that "...Defects shall[D1D2D3] be identified, documented and dispositioned by the Manufacturerbased on the design, service and customer requirements. Disposition is thedetermination of how defects are to be treated, and include, but are notlimited to, rework, scrap, use-as-is, or repair."
Henceall process or product defects as defined in the J-STD-001 shall beidentified and dispositioned per this requirement.
Paragraph 13.1 Rework, states "...hardware defects shall [N1N2D3] bedocumented before rework. Rework for Classes 1 or 2 should and for Class 3 shall[N1N2D3] be documented.:
Additionallyit states in Paragraph 13.2 Repair "... is the act ofrestoring the functional capability of a defective article in a manner thatdoes not assure compliance of the article with applicable drawings orspecifications. A hardware defect shall not [N1N2D3] be repaired untilthe discrepancy has been documented. The repair method shall [N1N2D3] bedetermined by agreement between the Manufacturer and the User."
Thereforeto answer the question "Does it specifyin an IPC document that customer approval is required for class 3 repairs?" theanswer is yes per paragraph 13.2 Rework.
This is very similar to the MRB (Material Review Boards) whowere involved in the disposition of rejected product, with the additionalinformation of how the rework or repair is to be conducted and that informationcan come from the IPC-7711/7721 Rework, Modification and Repair ofElectronic 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 anyIPC requirements that customer boards need customer approval prior to repair.It all depends on what type of contractual agreement is made with customer forrepairs. 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'sapproval and rework does not regardless of the class of the product. However,the purchase order is the governing document to establish the contractrequirements.
Engineering and Operations Management
Georgian Simion is an independent consultant with 20+ years in electronics manufacturing engineering and operations.
Contact me at email@example.com.