I agree with Clark's statement. As Mike pointed out, marking may only be required out in the field or on the test bench, etc. Those individuals may not make it a habit to carry around a loop so they can read the markings. Gary On 6/17/2010 9:17 PM, Clark Webster wrote: > > > ________________________________ > > From: IPC-600-6012 on behalf of Nick Koop > Sent: Thu 6/17/2010 1:47 AM > To: [log in to unmask] > Subject: Re: [IPC-600-6012] Legibility of Marking > > > > John, > > I agree 2X seems more appropriate. Higher magnifications are unlikely > to improve legibility, and the whole point of legend marking is to be > legible to the unaided eye anyway. > > Nick > > Nick Koop > Minco Products, Inc > Flex Circuits Product Marketing Manager > Ph 763 586-2846 > Mobile 763 245-4825 > > > >>>> Thomas<[log in to unmask]> 6/16/2010 10:48 PM>>> >>>> > We indeed have an issue as 3.1.4 allows up to 3X! This needs to be > addressed quickly. My position is 2X should be max. Tom > > Sent from my iPhone > > On Jun 16, 2010, at 12:59 PM, "Dupriest, Don"<[log in to unmask]> > > wrote: > > >> Yea, looked at the 4781 some and it does good job of covering >> "qualification testing" but I think I saw it points back to 6012 for >> > >> production lot testing. So I think our job will be to add to table >> > >> 4-3 lot conformance AQL as required. The table of qualification >> test is too much so we just need to pick what makes good sense for a >> > >> lot to lot check. >> >> C. D. (Don) Dupriest >> Lockheed Martin - MFC >> Advanced Manufacturing Technology >> member of: >> Production Technical Excellence Staff >> Ph. 972/603-7724 fax: 972/603-9052 >> Email: [log in to unmask] >> >> >> >> >> -----Original Message----- >> From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of John >> Perry >> Sent: Wednesday, June 16, 2010 2:45 PM >> To: [log in to unmask] >> Subject: Re: [IPC-600-6012] Legibility of Marking >> >> Hi Wendi and Don, >> >> When we revised IPC-A-600 and IPC-6012, we put pointers in both of >> those documents to the new IPC-4781 qualification and performance >> specification for legend and marking inks (released in 2008). Prior >> > >> to IPC-4781, there was no industry standard for legend and marking >> inks aside from an obsolete MIL spec. >> >> This document is modeled after IPC-SM-840 for solder mask, and like >> > >> that document, has requirements for adhesion to printed board >> laminate as well as solder mask. >> >> We say in 3.2.10 of IPC-6012C that "Marking inks shall be permanent >> > >> and shall conform to IPC-4781 or be as specified in the procurement >> > >> documentation. >> >> I agree with Don though, that we should examine this further within >> > >> our two task groups. IPC-A-600H says the boards shall be inspected >> > >> at no greater magnification than 2X for marking legibility. >> IPC-4781 says the following: >> >> 3.1.4 Legibility After marking is tested in accordance with the >> methods outlined in this document, excluding flammability, markings >> > >> which are missing in whole or in part, faded, smeared, or shifted >> (dislodged) to the extent that they cannot be readily identified at >> > >> not more than 3X >> magnification, shall constitute failure. >> >> Opps... >> >> Best Regards, >> >> John Perry >> Technical Project Manager >> IPC - Association Connecting Electronics Industries® >> 3000 Lakeside Drive # 309S >> Bannockburn, IL 60015-1249 USA >> +1 847-597-2818 (tel) >> +1 847-615-7105 (fax) >> +1 847-615-7100 (Main) >> [log in to unmask] >> www.ipc.org >> >> >> >> -----Original Message----- >> From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of >> Dupriest, Don >> Sent: Wednesday, June 16, 2010 1:55 PM >> To: Listserv IPC-600-6012 >> Subject: Re: [IPC-600-6012] Legibility of Marking >> >> Hi Wendi, I would say yes it applies to component marking (reference >> > >> designators). Examples in 600 mostly reflect numbering (like >> traceability) but one example photo shows a component symbol. As to >> > >> legibility; I would prescribe to if you can interpret the letters or >> > >> symbol with 2X it is fine. However, this section probably could >> stand some more work. One thing we have noticed is 6012 does not >> specifically address adhesion for marking like solder mask is >> covered in 600 and 6012. It references a permanency requirement so >> > >> one would assume tape test and/or solvent resistance would be >> applicable. But a tape test may be too difficult to pass for some >> really small feature sizes/designator letters. >> >> Guess just another thing to add to the committee to do list. >> >> C. D. (Don) Dupriest >> Lockheed Martin - MFC >> Advanced Manufacturing Technology >> member of: >> Production Technical Excellence Staff >> Ph. 972/603-7724 fax: 972/603-9052 >> Email: [log in to unmask] >> >> >> >> -----Original Message----- >> From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Wendi >> > >> Boger >> Sent: Wednesday, June 16, 2010 1:05 PM >> To: [log in to unmask] >> Subject: [IPC-600-6012] Legibility of Marking >> >> Everyone, >> >> >> >> Does section 2.8 Marking in IPC-A-600 apply to Legend (component >> mark)? We are increasingly seeing designs with very small legend >> features causing discussions at final inspection as to whether they >> > >> meet >> the requirement for legibility. From what I understand legible >> means at >> no more than 2x you can understand what the symbols are. Fussiness >> > >> and >> filled in holes in letters are allowed if you can tell what the >> > letter > >> is. >> >> >> >> Would appreciate some guidance on this. >> >> >> >> Thanks, >> >> Wendi >> >> >> >> >> >> This communication is for use by the intended recipient(s) only and >> > >> may contain information that is privileged, confidential, >> proprietary and exempt from disclosure under applicable law. You are >> > >> hereby notified that any dissemination, distribution, forwarding or >> > >> copying hereof is strictly prohibited without the express written >> consent of DDi. If you have received this communication in error or >> > >> are not the intended recipient, you should destroy the message and >> any attachments or copies, and you are prohibited from retaining, >> distributing, disclosing, or using any information contained herein. >> > >> Please inform us of the erroneous delivery by return e-mail. 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