Rework on PCBA

[DEVISO]

Hi I would like to know more about how rework will be managed in an electronic manufacturing company under ISO13485. Everyday there will be defects from SMT process like missing/ misplaced components and if the PCBA belongs to a medical device, do we need to document rework procedure and records for all these inline SMT defects? We are following IPC-A-610 standard and for rework we follow IPC-7711 and IPC-7721. What should be the minimum requirement we need to establish to perform in process rework on smt components?

 

[outdoorsNW]

Can you write permission to perform specific types of rework per IPC-7711 into your overall procedures? Then the person doing the rework can quickly write something along the lines of "replaced C43 due to missing component."

 

[DEVISO]

As per ISO13485, prior to any rework, procedures should be documented, reviewed and approved and risk assessment should be performed to make sure no adverse effect on the product due to rework. How this can be implemented in electronic manufacturing industry following IPC standards for rework?

 

[Tidge]

As per ISO13485, prior to any rework, procedures should be documented, reviewed and approved and risk assessment should be performed to make sure no adverse effect on the product due to rework. How this can be implemented in electronic manufacturing industry following IPC standards for rework?

PCBA can be designed and manufactured in such a way that rework is very unlikely to cause the final PCBA to be non-conforming. For example: many types of surface mount components can be quickly replaced using a hot air tool for a short duration of exposure... generally this technique can be applied in a very low-risk way. Other types of components and assembly techniques could be more difficult to rework.

The IPC standards I was certified to (in another lifetime) were mostly inspection techniques but also some assembly IIRC. From memory: the IPC standards for inspections are explicitly to look for certain types of defects... with a perhaps implicit assumption that the presence of such defects would be indicative of an assembly that would be "non-conforming". The ultimate non-conformance could be functional, or it could just be a high likelihood of inevitable functional failure... but the IPC standards were developed without knowing what the functions of any manufacturer's assemblies are.

 

[outdoorsNW]

To take the documentation work out of most electronics rework, you can make your rework instructions a reference to the correct IPC document, revision, and section(s). Make sure a qualified person approves the rework. When it comes to verifying rework per IPC definitions, in most cases repeating the inspection that led to the rework is sufficient.

You may want to have your rework people IPC certified either to J-STD-001 Space, which requires a basic soldering skills test, or to IPC7711/7721 which is a much more difficult test.

Since the IPC defines rework methods, you can predefine what is and is not allowed, You can write into your quality system anyone with X training or certification is allowed to perform rework and document it. In my past experience, each serial number had a section inside the lot information in our ERP system that allowed quick tracking of rework.

I am wondering if you are making this more complicated than it needs to be. Is this in response to an audit, customer concern, or something similar. If yes, please post so the concern can be directly addressed.

Note FDA, ISO13485, and IPC definitions are somewhat different. IPC defines both rework and repair while ISO-13485 and FDA part 820 lumps the two terms together.

Tidge: It is very difficult to totally engineer out all possible needs for rework, as defined by IPC. Many medical products have too low a volume to justify the amount of engineering, equipment, and process development efforts required to engineer out PCBA rework.

 

[Tidge]

Tidge: It is very difficult to totally engineer out all possible needs for rework, as defined by IPC. Many medical products have too low a volume to justify the amount of engineering, equipment, and process development efforts required to engineer out PCBA rework.

When I mention "engineering for rework" in this context I'm referring to the choice of using surface mount v. thru-hole, avoiding BGAs, etc. That is: was the PCBA made to be easy to rework or not?

 

[DEVISO]

To take the documentation work out of most electronics rework, you can make your rework instructions a reference to the correct IPC document, revision, and section(s). Make sure a qualified person approves the rework. When it comes to verifying rework per IPC definitions, in most cases repeating the inspection that led to the rework is sufficient.

You may want to have your rework people IPC certified either to J-STD-001 Space, which requires a basic soldering skills test, or to IPC7711/7721 which is a much more difficult test.

Since the IPC defines rework methods, you can predefine what is and is not allowed, You can write into your quality system anyone with X training or certification is allowed to perform rework and document it. In my past experience, each serial number had a section inside the lot information in our ERP system that allowed quick tracking of rework.

I am wondering if you are making this more complicated than it needs to be. Is this in response to an audit, customer concern, or something similar. If yes, please post so the concern can be directly addressed.

Note FDA, ISO13485, and IPC definitions are somewhat different. IPC defines both rework and repair while ISO-13485 and FDA part 820 lumps the two terms together.

Tidge: It is very difficult to totally engineer out all possible needs for rework, as defined by IPC. Many medical products have too low a volume to justify the amount of engineering, equipment, and process development efforts required to engineer out PCBA rework.

It was related to a customer audit, where we have only the record of what rework was performed by who (rework operator who is IPC7711/IPC7721 certified) and the test results. But the concern raised was, who approves the rework and where is the risk assessment done that this rework had no adverse effect on the form fit or function of the product. We have a workmanship procedure stating rework of PCBA is performed according to IPC7711/7721 standard , but how to explain the risk assessment of rework and we cant submit for rework approval for all these in process SMT reworks which is performed by the certified operator. Will ISO 13485 allow a blanket statement in the workmanship procedure that the rework performed by the certified person according to IPC standard will not have any adverse effect on the form fit or function of the product?

 

[Tidge]

But the concern raised was, who approves the rework and where is the risk assessment done that this rework had no adverse effect on the form fit or function of the product.

"Who approves the rework?" is a rather straightforward request from a medical device manufacturer to a supplier of PCBA... however this should have come up when the manufacturer was working out control plans with the PCBA supplier. A manufacturer should be able to come up with an evaluation and approval process for PCBA that require rework. It may of course slow things down, but if the customer wants it, this isn't unreasonable and they will accept the consequences.

"Make sure rework had no adverse affect" is a loaded consideration. In order to ask about this, the customer (the medical device manufacturer) must have some assessment that the non-rework build process is not having an "adverse effect."

If the defects were found via some sort of validated process, putting the PCBA back through that same process will probably satisfy most customers. If the customer gets specific about questioning the means of rework, having the folks who do the rework be certified via an IPC trainer ought to close any remaining gap in consensus. If the customer has evidence that PCBA that were reworked are NOT meeting form/fit/function, this should come up in the context of a SCAR, not an audit.

A supplier keeping records of which PCBA were reworked and in what way could be valuable for a medical device manufacturer in a variety of ways. For example, a PCB that has an unusual amount of metal in one spot of one layer could manifest in a specific type of assembly failure, so the designer might want to redesign, or perhaps the assembly process could be modified to improve yields.

 

[outdoorsNW]

Reading between the lines, this sounds like a customer with limited knowledge of PCBAs and may be overreacting to the common, extremely minor, and low risk rework in PCBAs. Plus the medical field typically does not make the clear distinction between rework and repair the way IPC does.