September 20, 2007 The bottom line is that inspection criteria (Class 1 versus Class 2 versus Class 3) alone does not define the overall qualify of a product regarding expected life of fielded product. I argued with IPC Task Groups for years that IPC specs should be class less. We argued this concept vigorously when we first developed NATIONAL-STD-SOLDERING (aka. J-STD-001). I wanted IPC specs to be based solely on what is required technically, and not based on what type of equipment was being produced. I lost. The real issue that folks should strive for in any manufacturing process is good process control. If you have a good product design and an effective system of process control in place, based on the physics of soldering, solder should go where it is supposed to go and you should wind up with a good quality solder joint regardless of what product class is specified (Basically you should always get Class 3 by default). Adding product classes to IPC specifications just opens the door for folks to ship less than perfect quality products. Although implementing a well documented (using metrics) and effective process control system costs $ up-front, the long term payoff is better quality and less $ based on equipment lifetime considerations and customer satisfaction. If you are looking to save money, the answer is not to revert to a lower product class designation. A better approach is to spend some up front $ and form a team of knowledegable folks to do an in-depth evaluation of your existing manufacturing processes by engaging one or more Black Belts to do a Kaizen event or a Value Stream Map (VSM) of your existing manufacturing processes to drive for continuous process improvement. Only then will you truly achieve long term product quality and lower life time cost reductions. >From: Rob Strecker <[log in to unmask]> >Reply-To: TechNet E-Mail Forum <[log in to unmask]>, Rob Strecker ><[log in to unmask]> >To: [log in to unmask] >Subject: [TN] Reliability of Class 1,2,3 >Date: Wed, 19 Sep 2007 08:15:05 -0600 > >I was wondering if there is any documentation out there stating the >reliability of products built to IPC class 1 compared to class 2 or 3? >We are a class 2 manufacture and are looking at reducing our >inspections, however will this put us in the class 1 category by default >if we only catch defects at functional test? What inspection must we do >in order to maintain class 2? > > > >Thanks, > >Rob > > > > >--------------------------------------------------- >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 -----------------------------------------------------