7.5.2 Validation of Processes for Production and Service Provision

S

Shredder

I have smoke coming out of my ears trying to understand the "special processes" portion of this 7.5.2.

For the past three years, we have passed AS9100 audits with an exclusion to 7.5.2., since this states: "the organization shall validate any processes for production and service provision where the resulting output cannot be verified by subsequent monitoring or measurement, and as a consequence, deficiencies become apparent only after the product is in use or the service has been delivered"... "often referred to as special processes". Ok, check, got that part... Any work that we do with an outside service supplier comes back to our shop, goes through a thorough QA review prior to being sent to the customer. We make PWB's, no assembly, that's it, copper, laminate, holes and traces. So for us, we do not do any special processes that cannot be validated in house... any OSS processes take place PRIOR to final QA testing procedures, therefore the process IS validated in house, before delivery, our failures don't make it out the door. Any failure that takes place outside of our company after delivery would realistically be due to components and/or assembly, which we do not have any control over or responsibiltiy to. Anyway...

I have had an auditor recently tell me regarding our exclusion and I quote "Bull---t! If your telling me you don't have special processes you're lying", my explainations falling on deaf ears :argue:. I don't feel like changing my entire quailty system for a client auditor, but at the same time I'm not sure how to address the validity of this claim, successfully. Any feedback from anyone out there?

A sincere advance thank you to anyone who can help me wrap my brain around this finding.
 
J

Jason PCSwitches

You state "around this finding", so that tells me you got an NC on this correct?

What was cited as the evidence on noncompliance??
 
S

Shredder

My apologies, I should have clarified. Yes, I have a "nice" audit finding over this issue and a request for corrective/preventative action that I have to complete.
 
J

Jason PCSwitches

My apologies, I should have clarified. Yes, I have a "nice" audit finding over this issue and a request for corrective/preventative action that I have to complete.

How does the NC read - verbatim??
 
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S

silentrunning

My thinking is that until he finds the special process that you're not validating, he has no basis for an NC.
 

AndyN

Moved On
How can I put this to you? Pretty much your whole process of making a circuit board (well, the important bits, the trackwork, plating etc) is a "special" process!

The process of plating has always been considered a special process! The process parameters and controls are what define the quality of the plated pcb - how much plating is deposited, the shaped etc. I can tell you from some hard won experiences, that the quality of adhesion/plating etc cannot be inspected.

I probably wouldn't have phrased it in that manner, but maybe it's because your system doesn't call it a 'special' process, because it's not special. You do, however, have to meet those requirements, since you are plating.

BTW - I was responsible for pcb quality for a number of interesting and informative years!
 
S

Shredder

Basically: "within the aerospace industry, fabrication of PWB is considered a special process; however Company X has taken an exclusion to this requirement".

My response is I can understand how big aerospace company considers my product a special service they outsource [to my company], but since it's my product, my processes and validations, why does my system automatically have requirements for becoming a mirror of theirs? It's confounding!
 

Sidney Vianna

Post Responsibly
Leader
Admin
So for us, we do not do any special processes that cannot be validated in house... .
So, do you validate the process or not? You are claiming an exclusion to 7.5.2, but you just wrote that you "validate the process" in house. There is a difference between inspection and validation. Many people mistakenly believe that a thorough visual inspection negates the need for process validation.

In principle, the manufacturing of printed wire boards contain several processes that could be deemed special, such as: Chemical etching, lamination, exposed conductor plating and coating, solder resist, electrochemical migration, etc.

Chances are, you do have sub processes that should be validated. But to know for sure, a thorough review of your customer requirements and the specifications associated with your outsourced processes would have to be done. I don't think your auditor did a good job of articulating his statement of nonconformity, but I don't think he is totally off the mark here.
 

AndyN

Moved On
Basically: "within the aerospace industry, fabrication of PWB is considered a special process; however Company X has taken an exclusion to this requirement".

My response is I can understand how big aerospace company considers my product a special service they outsource [to my company], but since it's my product, my processes and validations, why does my system automatically have requirements for becoming a mirror of theirs? It's confounding!

You simply have to be able to answer the question 'Can you check the quality of the track work, plating, adhesion of plating, plating thickness, track undercut, etc by inspecting the product, and assure the quality (at a reasonable cost, too) to the customer?

The answer is NO! It isn't possible. (at least not in the more advanced markets)
 
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Big Jim

Admin
I have smoke coming out of my ears trying to understand the "special processes" portion of this 7.5.2.

For the past three years, we have passed AS9100 audits with an exclusion to 7.5.2., since this states: "the organization shall validate any processes for production and service provision where the resulting output cannot be verified by subsequent monitoring or measurement, and as a consequence, deficiencies become apparent only after the product is in use or the service has been delivered"... "often referred to as special processes". Ok, check, got that part... Any work that we do with an outside service supplier comes back to our shop, goes through a thorough QA review prior to being sent to the customer. We make PWB's, no assembly, that's it, copper, laminate, holes and traces. So for us, we do not do any special processes that cannot be validated in house... any OSS processes take place PRIOR to final QA testing procedures, therefore the process IS validated in house, before delivery, our failures don't make it out the door. Any failure that takes place outside of our company after delivery would realistically be due to components and/or assembly, which we do not have any control over or responsibiltiy to. Anyway...

I have had an auditor recently tell me regarding our exclusion and I quote "Bull---t! If your telling me you don't have special processes you're lying", my explainations falling on deaf ears :argue:. I don't feel like changing my entire quailty system for a client auditor, but at the same time I'm not sure how to address the validity of this claim, successfully. Any feedback from anyone out there?

A sincere advance thank you to anyone who can help me wrap my brain around this finding.

I suspect that you do not have a clear understanding as to what a special process is.

In the simplest of terms, it is a process that you cannot tell the outcome of from normal inspection. Some processes that nearly always fit into that category are welding, brazing, soldering, and plating. Since plating is part of what you need to do to make your product, it fits into that category.

Lets take a closer look at the processes mentioned. Although you can tell a lot about a weld from inspection, you really can't tell if there was sufficient penetration to properly bond two pieces of metal together. The only absolute way to know for certain is to pull it apart, destroying the piece, to confirm that it did not come apart at the seam, but that it pulled parent metal with the weld. If you need to destroy the part to confirm a proper weld, how can you sell it?

Brazing and soldering are similar to each other. It is not welding, since you do not mingle the metal pieces. It is necessary to get the molten solder or brazing material hot enough to flow over the entire mating surface as well as have the parts clean enough and the use of appropriate flux so that there is a good bond. Again, you can tell a lot about a solder joint from inspection, but it is possible to have a good looking joint that is unsatisfactory. Again, you need to destroy it to tell for sure and that makes it unsellable.

Plating quality cannot be told simply by inspection although you can tell a lot. You cannot tell if the plating will flake off when bent simply from inspection. You cannot tell that the surfaces were clean enough to ensure the proper bond of the plating material to the base material. Once again, you can tell more from a destructive test, but then you can't sell it.

So what do you do when you can't tell the quality from normal inspection (verification)? You validate it. How do you validate a special process? The answers are given in the letters of 7.5.2.

Again, in the simplest of terms. You can validate plating by following the plating specification (recipe) and part of the validation is keeping records of your process controls. Tank chemistry logs, recording the math used to calculate the tank times and the rectifier settings. Recording the actual tank times and rectifier settings.

You validate soldering by a combination of training and then visual inspection following a known set of standards. The J standard for training the operators comes to mind. The number of the related one does not come firmly to mind, but I think part of the number is 160. Both of these are revised every five years or so. The most current is 2010. Both of those standards are not fully useful without the training aspect.

There is more than one way to validate welding, depending on the application, but the premier method is by certifying the welder. The welder is trained, then samples of his welding are provided to a welding certification lab where it undergoes a battery of NDT followed by pulling the samples apart. The certifications are specific to the metal involved, the type of equipment used, the thickness of the metal, the type of joint, and even the position of the weld (gravity's effect on the molten puddle plays a big factor). To be a broadly certified welder, it takes a lot of samples so it can be a very expensive undertaking. Once the welder is certified it is presumed that the welds are good, although in some schemes the testing has to be repeated from time to time.

It is very likely that you actually are validating your special processes and don't realize it.

A really big thing to point out is that just because earlier auditors didn't catch it before doesn't mean it is right.
 
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