interesting.... I have IPC-2222 dated February 1998. Table 4-10 is not listed in the "figures" section of the Table of Contents (the last Table in that chapter is 4-6) and the first sentence of 4.3.7.5 says "see table below" but there is no table. Was there an amendment to IPC-2222? onward thru the fog, Jack On 4/29/08, [log in to unmask] <[log in to unmask]> wrote: > > My hardcopy of IPC-2222 dated February 1998 does have a Table 4-10. > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Jack Olson > Sent: Tuesday, April 29, 2008 12:39 PM > To: [log in to unmask] > Subject: Re: [TN] TechNet Digest - 26 Apr 2008 to 28 Apr 2008 (#2008-114) > > Phil, > > I just found it. > Look in section 4.3.7.5 of IPC-2222 > > It is expanded to Table 4-10 of IPC-2222A working draft > and it is amazingly more complicated than my "10%" answer!!!! > > (I don't know if Revision A is published yet. If it is, refer to THAT) > > > * > > Table 4-10 Printed Board Thickness Tolerance Levels * > * > > Board Thickness (mm) [in] * > * > > Tolerances by Level * > * > > Level * > * > > A * > * > > B * > * > > C * > * > > As applied Base to Base * > > ˜ 1.6 [0.062] > > + 15 % > > + 12 % > > + 10 % > > > 1.6 to ˜ 2.3 [0.062 to 0.090] > > + 12 % > > + 10 % > > + 7 % > > > 2.3 to ˜ 3.8 [0.090 to 0.149] > > + 10% > > + 7 % > > + 5 % > > > 3.8 to ˜ 6.4 [0.149 to 0.251] > > + 10% > > + 7 % > > + 5 % > * > > As applied over Final Finishes and Coatings * > > ˜ 1.6 [0.062] > > + 20 % > > + 15 % > > + 12 % > > > 1.6 to ˜ 2.3 [0.062 to 0.090] > > + 15 % > > + 12 % > > + 10 % > > > 2.3 to ˜ 3.8 [0.090 to 0.149] > > + 12 % > > + 10 % > > + 6 % > > > 3.8 to ˜ 6.4 [0.149 to 0.251] > > + 12 % > > + 10 % > > + 6 % > > 1.6 = 0.062 > > 2.3 = 0.090 > > 3.8 = 0.149 > > 6.4 = 0.251 > > > On 4/29/08, Jack Olson <[log in to unmask]> wrote: > > > > Phil, > > > > I can only give you a partial answer (because I can't find it in any IPC > > docs either!) > > The way you are specifying it is fine, except you must allow > > +/-10% tolerance > > (I know it is 10%, but I searched every relevant doc I have for "10%", > > can't find it) > > > > The reason it is most often measured to include the plated metal, > > is because in the past it most often mattered for edge connectors. > > The edge connector had to include the distance from the gold finish > > on one side to the gold finish on the other > > > > Jack > > > > p.s. Final thickness is never measured to include the mask. > > p.s.s. I can post your question over on the IPC Designer's Council if > you > > want me to? > > > > > > > > > > Phil Nutting <[log in to unmask]> > > > Sent by: TechNet <[log in to unmask]> > > > 25.04.2008 21:52 > > > Please respond to > > > TechNet E-Mail Forum <[log in to unmask]>; Please respond to > > > Phil Nutting <[log in to unmask]> > > > > > > > > > To > > > [log in to unmask] > > > cc > > > > > > Subject > > > [TN] Specifying board thickness > > > > > > > > > > > > > > > > > > > > > Hi Technetters, > > > > > > We are reviewing how we specify finished circuit board thickness to > make > > > sure we get what we think we specified. Recent events have placed > what > > > we > > > specify under scrutiny. I've looked through IPC-2221, IPC-2222, IPC- > > > 4101B, IPC-6012B and IPC-7351A with no luck. > > > > > > Currently our documentation calls for 0.059" finished board thickness > > > without measuring the thickness of the copper. Presumably when the > > > copper > > > is added we get to 0.062" finished thickness which is important when > we > > > start stacking circuit boards on standoffs. > > > > > > How do others specify circuit board thickness? > > > > > > Is there an IPC spec I can quote chapter and verse? > > > > > > Thanks in advance. > > > > > > Phil Nutting > > > Design for Manufacturing Engineer > > > Kaiser Systems, Inc. > > > 126 Sohier Road > > > Beverly, MA 01915 > > > voice: 978-922-9300 x1310 > > > fax: 978-922-8374 > > > e-mail: [log in to unmask] > > > www.kaisersystems.com > > > > > > >