The Smart Group has produced a nice little set of images that seem suitable for solder paste print acceptance criteria. As you suggest, direct measurement of solder paste height is not one of the acceptance criteria. Though, it may make sense to include height, if it can be measured easily enough to be cost effective. Variation is the attribute of interest. If you are getting 1 to 1.5 mil variation and start seeing 3 or 4 mil something is up. > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Tempea, Ioan > Sent: Wednesday, April 21, 2004 10:46 AM > To: [log in to unmask] > Subject: [TN] IPC standard on paste height? > > Hi Technos, > > the fact that paste height is maybe not a relevant and > worthwile factor to measure has been brought up several times > on this forum. My experience also says that I will have the > same acceptable joints whether using a 6 mil stencil or a 5 > mil one, if the paste deposits are uniform (nice bricks). But > if I write a procedure setting the control zone between 5.5 > to 8 mils I will get flamed by both the customers auditing > the process and my bosses. > > Is there any standard/handbook/specification that sets > control limits for the height of the paste after stencil > printing? Or which prescribes other measurable indicators for > good printing? > > I must mention that I only have an LSM that can measure the > height, no volume checking available. > > Thanks, > Ioan --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------