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Saponifier needed to stop

Michael Parker


Saponifier needed to stop | 5 October, 2001

I am looking to learn of possible causes and solutions for the following problem.

A potential customer is demanding that I use a saponifier in the aqueous wash, he has lab test results of former CM's products that leads him to believe it is necessary.

The problem is at a PGA socket, its growing oxidation on the contacts. This has been verified by a independent lab using an environmental chamber. The product is an industrial computer PCBA that is expected to have a 7-10 year working life.

The customer claims that DI water alone is not good enough. I normally operate at 18 Megohms resistivity with my water. He wants to add the saponifier, thinking its a detergent that cleans better. I think the saponifier is acting like a coating, leaving a residual film that stops or slows down the oxidation of the socket leads.

All information you can share would be greatly appreciated.

Help me Mr. Wizard!

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Saponifier needed to stop | 6 October, 2001

Mr. Wizard is not currently available. You get the wizzer. Maybe your dream date will show later.

Get your own lab tests done. Show your potential customer that your boards are clean. That�s the issue. The issue is not how you go about cleaning them.

Saponifiers are very useful, depending on the type of flux. They�re designed for rosins and resins. The two primary methods, nowadays, for cleaning rosins and resins are: * Semiaqueous. A cleaning process using a solvent followed by a hot water rinse and drying. * Saponifiers. Alkaline chemicals, added to water, that convert rosin/resin flux residues in the water to soluble soaps.

Assuming you�re using an aqueous flux, a saponifier won�t do dip about removing flux res. Even if you wanted to use a saponifier with your aqueous, is your washer BIG enough [have enough sections / isolation] to run a saponifier?

Responding to the conflicting theories: ADD THE SAPONIFIER, IT�S A �NEW & IMPROVED� DETERGENT: It�s not a detergent. It�s a badass base [alkali] that when dissolved in water produces hydrogen ions. The pH of a saponifier must be at least 10.5 to get the hydrogen peroxide in the water going. [Watch your safety compliance manager snap to attention, when you tell him that!!!] SAPONIFIER IS A PROTECTIVE COATING: If the sections of the washer that come after the saponifier section [i.e., Wash 1, Wash 2, Rinse, DI Rinse, etc] are not operating, there will be a saponifier coating on the product. If left on the product, a coating of saponifier will be more disastrous than leaving flux on the product.

If I had to guess why a PGA socket was growing fuzz after aqueous wash, I�d guess that it wasn�t dried properly. If you fill a PGA socket with water and then add the component, it could take a looooong time to dry-out, all the while presenting the perfect medium for corrosion and other crunchy things. Even if you don�t stuff the socket, it�ll still take a looong time to dry.

An alternate hypothesis takes the �poor drying� spiel [above] a step further and speculates the socket was never properly cleaned, still retaining flux / wash res. It would be interesting to review the lab test results to determine what the source or ID of the residue on the sockets.

I�d say the solution is to either: * Loose the socket. [I know. I know. �The socket is important to our customers� ability to maintain the board." Sure. Customers don�t replace processors, they replace memory. Wuttevah.] * Selective solder the socket in NC, as a third process. * Dry the socket after cleaning. * "Seal" the socket with a low-res tape to prevent solder / cleaning materials from entering the socket. * Determine if there is a more appropriate socket.

For more on saponifiers: contact Frank Cala at Church & Dwight [], he�s written a [THE???] book [�Aqueous Cleaning Technology For Electronic Assemblies� F. R. Cala & A. E. Winston; Electrochemical Publications; ISBN 0 901150 31 2] on saponifiers, a SMTA member, and very smart.

Always remember: Give the customer what he asks for, so long as he�s not too retarded.

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Michael Parker


Saponifier needed to stop | 8 October, 2001

Dream date? Would that be the St. Pauli girl? I like 'em built for comfort!

Thanx for the reply. As usual, you are a fount of information and I will be checking the resource you mentioned. I haven't had much direct experience with saponifiers, now that you have explained the basics, I can proceed.

The customer in question is adamant about using a saponifier because his environmental testing of the PCBA came out "clean" once a saponifier had been used. I could not get much info out of him. He didn't know the paste or processes used by his former CM. I will probably get a batch cleaner for PCBA's for the saponifier and leave my in-line system as is.

I am still trying to avoid saponifiers if I can prove a process that doesn't need it, that includes an independent labs study.

As far as replacing the socket, I don't know what the customer will agree to, it seems that most of my customers with Pentium class processors want sockets. That is probably out of fear of having to replace expensive chips by SMT rework methods versus an easy remove and replace. Makes sense in a proto run but not for prolonged production.

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Saponifier needed to stop | 8 October, 2001

No wizard here just a troll....Sorry I can not spout a Fountain of information Like "The Dave F" but here is an additive..... Having worked at a Lab for testing Soaponifiers, cleanliness, and contamination when a customer says "we had a lab check it and its clean" scares the bejesus outta me and I equate it to a used car salesman "Have I got a deal for you" or even more relavant an internet salesman "Have I got a Dot Com for you"...OK OK maybe not that bad but the effect is the same "DO YOU BELEIVE IT" Have it retested. We have had customer tell us it is clean only to find out they used street water and a monsterous amounts of chlorides were left behind. We would ask for the test proceedures and results and duplicated the test using industry standards. I agree with Dave....the Socket maybe harboring residue.

Some of the Soaponifier manufacturers have some great info available...Zetron, Petroferm, and Kyzen all have good information. Also, Aqueous Technologies have good information to be shared.

Hope this helps,

Cal Manncorp

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Michael Parker


Saponifier needed to stop | 9 October, 2001

Cal - even trolls were smart enough to outwit most back in the day.

I appreciate your input as well as Dave's. I agree about doing the retest. I just didn't have the right info, just some gut feel that made me question the purported lab results. I have accessed to websites to get technical info on saponifiers and Kyzen has an excellent tech article, a study done for Data General. I will probably get my lab to emulate that procedure and see what flies. I cannot use the Kyzen product, too much regulatory baloney to deal with over an alcohol based saponifier. I'll probably go with an inorganic cleaner, if that is the necessary outcome.

Thanx once again.

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Michael Parker


Correction on misinformation | 9 October, 2001

I just realized my last posting has some incorrect references. Blame it on last nights sour mash! (St. Pauli girl didn't respond!)

The article I referenced was found at the AlphaMetals website, a study done for AlledSignal, in conjunction with Church & Dwight (Armakleen brand, I believe)

The article also mentioned an alcohol based saponifier used in the study. That's probably where I associated KYZEN with the article.

My bad.

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