IPC-A-610B (issued January 96), chapter 10, covers SMD solder joints, but only for externally view. §4.2 (fig. 4-15) says: "(...) blow holes, pinholes (...) are nonconforming process indicators (...)". But a "nonconforming process" is not the same as a "nonconforming product", therefore see foreword ("Nonconforming Process Indicator Condition"): " (...) not affect the form, fit & function of a product (...) the product affected will be dispositioned Use as is (...) if the company does not have a documented Process Control system (customer approved, J-STD-001, sic!), then all Nonconforming Process Indicators must be treated as Nonconforming Defects (...)" voila! Enough collective wisdom? Sometimes I have the impression plane IPC should reevancelicate the short basic principles of the requirement flowdown for electronic assemblers. The backbone would be: * J-STD-001B (soon C) for soldered electronic assemblies. Based on J-STD-001B (as backbone), table 3-1 - and the up-dates during the meanstime - for rigid pwb's the bones could be defined as: * IPC-2221 and IPC-2222 (rigid) and/or(?) IPC-D-279 (SMT) for design/layout, * IPC-6011 and IPC-6012 and IPC-A-600E for PWB manufacturer (to refer on the purchasing spec's!) Other specifications (fishbones) would be adressed by the standard-inherent requirement flowdown (IPC-SM-782, IPC-4101, IPC-SM-840, ev. IPC-CC-830 et al) Bernhard, near Zürich (for you: Zurich) PS, to the guru's: there is a litte conflict between IPC-6012 § 3.11.1 (" .. 0.1% ..") and Appendix A, p. 27, §3.11.1 (".. 9.01% ..), it isn't? -----Ursprüngliche Nachricht----- Von: Automatic digest processor [SMTP:[log in to unmask]] Gesendet am: Freitag, 12. November 1999 07:00 An: Recipients of TechNet digests Betreff: TechNet Digest - 11 Nov 1999 (#1999-367) At 10:45 AM 11/11/99 -0500, you wrote: > Hi gang, > We are cross-sectiong some solder joints, and are seeing some > voiding inside the joint itself, that appears to be "air pockets" that > were inside the joint when reflowed. There is no visible indication > externally of any voiding, but it is fairly prevalent inside various > component solder joints when cross-sectioned. > > I cannot find criteria or mention of this in the specifications I > have. ANSI/IPC-A-610A shows voiding criteria for thru-hole components, > but none for SMD. > > Does anyone have knowledge they can share on this topic? Is there a > spec on internal SMD joint voiding available? Do you guys and gals see > this occasionally in your joints? > > Please, enlighten me with your collective wisdoms! > TIA! > > Jeff Hempton > United Technologies Electronic Controls ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################