That's correct. Thanks John. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of John Burke Sent: Wednesday, August 10, 2005 10:58 AM To: [log in to unmask] Subject: Re: [TN] PCB Storage I have done this with a regular digital scale, you just have to use a large board sample (10 - 20 - or a hundred depending on board size) to take account of the scale last digit resolution. ------------------------------------ Avanex John Burke Senior Manager RoHS Compliance [log in to unmask] 40919 Encyclopedia Circle Fremont CA 94538 tel: 510 897 4250 fax: 510 979 0189 mobile: 510 676 6312 ------------------------------------ -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Schaefer, Chris Sent: Wednesday, August 10, 2005 8:49 AM To: [log in to unmask] Subject: Re: [TN] PCB Storage Thank you... So do you know of a chemical cleaner that could be used in a batch cleaner of other that could clean tin/ lead HASL plating? Oh and from what I gather you use a precision scale to measure the suspect boards with moisture versus boards that should not have any moisture - is this correct? If true would the different materials used in manufacturing the boards and the tolerances of weight +/- throw off your readings? or would it be so minimal that it is not a factor? Thank you for your help... Much appreciated -----Original Message----- From: Stadem, Richard [mailto:[log in to unmask]] Sent: Wednesday, August 10, 2005 9:35 AM To: TechNet E-Mail Forum; Schaefer, Chris Subject: RE: [TN] PCB Storage Get a copy of IPC-STD-030B. Read it. Read the part that says the bake procedure is used to dry the board as well as the MSD components. Read the part that says the times/temperatures are a guideline. Figure out what temperature brings the moisture content down to less than 10% (lease a precision scale) without sacrificing solderability (typically 105C for 8-12 hours depending on size and type). Perform a DOE to determine what, if any, effect the baking has on solderability (DPMO up?). Train the operators in proper handling for MSDs and PWBs in a high-humidity environment. Get a McDry dessicator or two or three. Store your boards and parts in them. Baking of pwb's with ENIG finish to remove the moisture can cause the nickel oxide layer (if present from poor plating processes) to become worse. No way to tell except run a controlled lot and monitor the DPMO. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Schaefer, Chris Sent: Wednesday, August 10, 2005 8:51 AM To: [log in to unmask] Subject: Re: [TN] PCB Storage Hello All, Hope you are all having just a wonderful day in the land of Milk and Honey! HELP PLEASE... We are currently in a situation in which we have little to no control of the humidity or temperature within our facility, and probably never will. We also do not have complete compliance to our procedures from the board vendors - so we do not receive the boards as we would like them (MBBag, appropriate desiccant and volume of desiccant, HICard, solderability test results, and ionic or other cleanliness test results from each lot/ date code set). This will not change in the near future either due to the fact that we need the boards so desperately we accept almost anything. Internally we have little if any discipline when storing/ handling the boards so we are constantly baking boards and performing solderability tests (especially during the summer months). We try to keep all board packaged in an MBB with HICard with a maximum of 20 boards per bag (zip-lock), but still have humidity failures (We are in Kansas - currently 50-85%RH depending on the day). How should this be done properly? Most of the boards are Class 3 products and we are required to use 2% no-clean flux with most product, so it is difficult to solder anyways. My first question is: Can you clean the tin/ lead HASL plating with a type of chemical to remove oxides so that we do not have to send the boards back to the vendor for cleaning or re-plating? If so what is the chemical? We have tried using A4512P (Kyzen product), but this does not work well. I have been told to get something with MEK in the mixture, but I don't know for sure. My second question is: When I have Gold Immersion plated boards and they are found in the packaging to have a failed HICard, how do you remove the moisture in the board? I have read that baking this type of plating actually reduces the solderability of the board. Is this true? Please HELP... I appreciate any support I can get. Thank You. Chris Schaefer Suntron Corporation Process Engineer 540 N. Rogers Road Olathe, Kansas 66062 913.393.5878 [log in to unmask] NOTICE: This message is intended for the use of the individual entity to which it is addressed and may contain information that is privileged, confidential and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by calling 913.393.5878 or returning the original message to us. -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Joe Russeau Sent: Tuesday, August 09, 2005 3:14 PM To: [log in to unmask] Subject: Re: [TN] PCB Storage Hi Paul, This is one of those "It Depends" questions. Most of the studies I have read with respect to storage of tin-lead HASL boards suggests a shelf life of up to twelve months. I have not seen any studies for boards with that surface finish being stored for that extended period of time (2 years). In my opinion, the ideal situation would be to purchase the boards as you need them and eliminate the issues surrounding extended storage. But since you already have the boards that is not an option. My 2 cents are to make sure that if you plan on storing them, that you package for the long term (2 years) and not for the short term (6mos). I would suggest vacuum packaging them in a clean, moisture and debris resistant container (e.g. Kapak heat-sealable bag). Depending on how many boards you have to store and their dimensions, it may be advisable to store them in a dessicated environment after vacuum sealing them. Controlling the humidity is going to be key to reducing the oxidation rate. Unless you use a nitrogen blanket to store the boards, you will not eliminate oxidation, but by controlling the humidity, you should be able to slow the process a bit. It is hard to say what will happen after long term storage, but I would suggest checking a few boards (provided you have extra) for solderability. If the boards solder as you expect, then you may be safe to continue to assembly. If you have problems, you may want to consider a mild saponified wash to remove any oxidation or debris that has accumulated from storage and repeat the solderability. Best of luck! Joe Russeau Process Analyst Precision Analytical Laboratory, Inc. 4106 Cartwright Dr. Ste. A Kokomo, IN 46902 P: 765-455-1993 F: 765-455-1996 E: [log in to unmask] ----- Original Message ----- From: "Black, Paul" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, August 09, 2005 2:31 PM Subject: [TN] PCB Storage > Hi All, > > I have some bare PC boards that may be built up in the future, but not > in the near future. I would like to put them into storage until needed (anywhere from 6 months to 2 years). The boards are .062" FR-4 HASL boards. What would you recommend for protection, assuming that the storage conditions are typical of an office environment? Would I have to do anything special to them when they are removed from storage? Any suggestions would be greatly appreciated. > > Thank you, > Paul Black > Manufacturing Engineer > Kronos > E-mail: [log in to unmask] > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e To > unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt > or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives Please visit IPC web site > http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 > ----------------------------------------------------- > > --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------