Inge In the range of 10- 100 mm/s on the floor Best regards Guenter >-----Ursprüngliche Nachricht----- >Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Jerry Dengler >Gesendet: Mittwoch, 23. September 2009 13:47 >An: [log in to unmask] >Betreff: Re: [TN] Knock, knock, knock on the heaven's door > >Hi Inge, > >We produced a product in the US for the US market that used a socket for >a PLCC. This product's usage went up and the customer sent the >production to China. At first all was well. After the production got >to normal levels, suddenly they were getting a high level of out of box >failures. These were all sent via ship. The earlier units were being >air freighted in while the factory in China got up to speed. We found >fretting at the socket to lead interface. We believe it is vibration >from the ship that causes it. > >Recently the factory in China made 1000 units. 500 were air freighted >and 500 were sent via ship. We left the 500 units sent by air on the >skid until the ocean units arrived. We then tested all 1000 units. 122 >of the ocean units failed. None of the air units failed. > >Jerry > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Hernefjord Ingemar >Sent: Wednesday, September 23, 2009 5:59 AM >To: [log in to unmask] >Subject: Re: [TN] Knock, knock, knock on the heaven's door > >Hi Guenter, >interesting. Very interesting. You got fretting issues at 28 Hz? Caused >by floor vibration? Really? I've been involved in several fretting >problems (aircrafts), but then we had much higher frequencies, maybe >multiples of lower resonances. Our equipments were transported by ship >to the other side of the planet, and it was then the problems started. >I'll check how they were transported, time at sea etc. > >Thanks again > >/inge > >PS. What level of vibration? > > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Grossmann, Guenter >Sent: onsdag 23 september 2009 09:41 >To: [log in to unmask] >Subject: [TN] AW: [TN] Knock, knock, knock on the heaven's door > >Hi Inge > >Vibrations around? I just had recently a similar problem in an >industrial environment. Failure analysis showed fretting on socket >spring- contacts. When I made vibration measurements I found quite a >spectrum of low level vibrations on the floor but a clear resonance at >28Hz in the rack. > >Best regards > >Guenter > > > >>-----Ursprüngliche Nachricht----- >>Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Inge >>Gesendet: Dienstag, 22. September 2009 21:34 >>An: [log in to unmask] >>Betreff: [TN] Knock, knock, knock on the heaven's door >> >>Well, not exactly that, but knock, knock, knock on a earthly board. One >>customer needs fix a intermittent problem asap. 19 inch racks with >>hundreds of PTH double sided boards, old technology, no BGAs, no QFMs >>etc, but lots, lots of DIPs. The edge contact fingers have a very thick >>and good gold over nickel, and the backplane connectors have really >>stiff double tongues. >>The >>contact pressure/sq is extremly high and I think the contact spots are >>really gastight once the board is plugged in. Now, they have electrical >>issues, and they've found, that the signals are interrupted or coming >>back when they knock on the boards. Someone is going to take a flight >>the other day to fix the problem. The electricians believe, stubborn as >>mules, that the only think needed, is to take out the boards and clean >>the edge contact fingers with a solvent and that will fix it. Myself, >>with quite many year's experience from connectors, I don't think that >>is the problem, because when such robust contact springs wipe along the >>contact fingers, they slide pretty deep into the gold and makes good >>connection. Each spring has double contact ridges, so the risk that >>some dirt should cause interrupts is minimal. There is more that talks >>against their theory, namely, that the problem is still there after >>plugging, deplugging more than once. I'm sure there is a solder joint >>issue, or maybe a bond wire problem in the packages. >>Logically, this later is more likely because you have thousands of >>solder/bond joints vs, just some one hundred edge connector ditto. A >>ratio like 10,000/100 per board. Without knowing all details, what is >>your general experience between the index finger and the big toe? >> >>/Inge >> >>--------------------------------------------------- >>Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 15.0 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 15.0 >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 15.0 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 -----------------------------------------------------