My first response would be that MIL-STD-2000 no longer exists. It has been superceded for quite a while now by industry standards such as IPC610 and ANSI-J. Those standards will state that if they do not violate conductor spacing and are firmly attached (which conformal would do a good job of), they are not a reject.... > -----Original Message----- > From: Kenny Bloomquist [SMTP:[log in to unmask]] > Sent: Wednesday, June 24, 1998 5:08 PM > To: [log in to unmask] > Subject: [TN] Mil-Std-2000A Question > > Here is another one of those sticky DOD questions. We have an > assembly, TH, > Mil-Std-2000A, that has been through assembly, test and conformal coat > (UR). As it was being plugged into an end item the operator noticed a > solder ball. How it was seen I'll never know because I can not see it > through a four power glass. That aside, under a microscope we were > able to > find 10 or 12 "tiny" solder balls. None of them reduced the conductor > with > below an acceptable spacing and all of them are encapsulated in > conformal > coat. > > Mil-Std-2000A - Paragraph 4.21.4 "Cleanliness of printed wiring, > boards and > assemblies. Printed wiring, boards and assemblies shall be free of > foreign > matter. This includes grease, silicones, flux residue, dirt, chips, > SOLDER > BALLS, insulation residue and wire clippings." > > My sensible self tells me that since these solder balls (micro-size) > do not > reduce the conductor spacing and they are encapsulated in UR that we > will > do more damage reworking these than leaving them alone. I would think > that > this is a process indicator and not a real defect. > > The Question: Does anyone out there in TechNet land have the > specmanship to > work through this or am I all wet? > > Thanks in advance for all responses. > > Ken Bloomquist > Sr. Principal Process Eng. > PRIMEX Aerospace Company > [log in to unmask] > (425) 881-8990 ext. 6645 > > ################################################################ > TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for > additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or > 847-509-9700 ext.312 > ################################################################ ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################