IPC standards committee updates: printed board design, base materials, fabrication processes and high speed/high frequency

Printed Board Design

The IPC 1-10b Current Carrying Capacity Task Group discussed goals for a future revision to IPC-2152, Standard for Determining Current Carrying Capacity in Printed Board Design. The revision will focus on high current transients, flexible printed boards, microvia structures and new printed board material types.

The IPC 1-10c Test Coupon and Artwork Generation Task Group reviewed a future Addendum to IPC-2221A, Generic Standard on Printed Board Design. The addendum will represent an “overhaul” of existing test coupon designs currently provided in section 12.4 of the IPC-2221A. To date, a new A/B-R plated-through hole evaluation coupon design has been approved as a replacement for the legacy A and B and A/B test coupon designs. In addition, the task group reviewed proposed designs for a new “D” interconnect resistance coupon, a new “E” insulation resistance coupon and a new “G” solder mask adhesion coupon.

Base Materials

The 3-11 Laminate/Prepreg Materials Subcommittee plans to work on Amendment 1 to IPC-4101C, Specification for Base Materials for Rigid and Mulitlayer Printed Boards later this year. This meeting covered: 1) The inclusion of DMA testing for Tg measurement along with DSC and TMA testing; 2) Requiring some form of hard data to suppport the STII concept; 3) Continued support of using another optional metric for laminate/prepreg resin, termed fracture toughness; 4) Agreement to include a new polyimide specification sheet into Amendment 1 for IPC-4101C; 5) the potential UL reclassification of numerous FR-4 systems; 6) Establishing another ad hoc committee to explore a potential reduction (or rationalization) of some current IPC-4101 specification sheets.

The 3-11f UL/CSA Task Group met jointly with the D-12a UL 796F/ UL 746F Task Group as a large number of topics addressed involve both “rigid” and “flexible” materials. As UL standards, UL 746E, UL 796C, UL 746F and UL 796F were recently and successfully voted upon by the UL Standards Technical Panel, the discussions that occurred during this combined meeting centered on the expected topics for future STP meetings.

The 3-11g Corrosion of Metal Finishes Task Group reviewed the proposed creep corrosion test plan using mixed flowing gas to accelerate corrosion formation. Most of this review was to bring people who were not current members of the 3-11g TG up to speed on this test plan as the member participation in the bi-weekly teleconferences has gone well.

The 3-12a Metallic Foil Task Group discussed the concept of non-contact copper foil surface roughness measurements. Chris Totten’s (Rogers Corporation) data from his own optical measurement equipment did not correlate with values generated by Gould Copper in Germany.  However, the amount of data generated by both operations was not large and the extent of test method control could definitely be improved, so Totten will continue to explore what is expected to be an improved, statistically valid test method for accurately measuring the copper foil’s treated surface roughness for use in the fabrication of high frequency printed boards.

The 3-12d Woven Glass Reinforcement Task Group addressed getting E-glass manufacturers to participate in testing the dielectric constant (permittivity) of their supplied formulation for E-glass at 1 GHz frequency. So far, of the four glass manufacturers who offered to participate in the test program approximately 18 months ago, only two have submitted data (one submitted only a single data point). Six new weave styles of E-glass from two weavers have been submitted for inclusion into IPC-4412A, Specification for Finished Fabric Woven from “E” Glass for Printed Boards, Amendment 3.

The 3-12e Base Materials Roundtable Task Group considered including the concept of STII for inclusion in IPC-4101. STII assigns a numeric value to a specific laminate material. According to STII, the higher the number that results from using the STII empirically-derived equation, the better the specific laminate material will withstand lead-free soldering assembly. After much discussion, the 3-12e TG participants voted that hard data or at least empirical results that correlate with “real world” assembly was needed.

Fabrication Processes

The 4-14 Plating Processes Subcommittee discussed the round robin test program within IPC-4556, covering ENEPIG (electroless nickel/electroless palladium/immersion gold) surface finish. Also, the group plans to revise IPC-4552, Specification for Electroless Nickel/Immersion Gold (ENIG) Plating for Printed Circuit Boards, primarily to establish an upper limit on the immersion gold thickness and reset the lower limit of gold thickness if the data supports such a change.

High Speed/High Frequency

The D-22 High Speed/High Frequency Board Performance Subcommittee continued work on IPC-6018B, Qualification and Performance Specification for High Speed/High Frequency Printed Boards. The group completed the update of acceptance criteria for resin smear within PTFE laminate as well as criteria for plating folds and copper wrap plating. The subcommittee also began updating acceptance testing and frequency tables within the Quality Assurance section of the document.

The D-24b Propagation Loss Test Methods Task Group considered an update to IPC-TM-650, Method 2.5.5.12, Test Methods to Determine the Amount of Signal Loss on Printed Boards. A proposal was made to replace the existing Root Impulse Energy (RIE) methodology with a lower cost loss methodology known as SET2DIL.

More information on IPC standards:
IPC status of standardization
IPC committee home pages
Upcoming standards meetings in September 2010
Purchase IPC standards

4 Comments

  1. Mordechai
    Posted November 7, 2010 at 5:31 am | Permalink

    I am looking for a draft of
    The IPC 1-10c Test Coupon and Artwork Generation .

    • Lotta
      Posted September 20, 2011 at 4:54 am | Permalink

      You have the monopoly on useful information—aren’t monoploies illegal? 😉

      • Kim Sterling
        Posted September 20, 2011 at 3:46 pm | Permalink

        That’s actually a very good question. IPC standards follow a process overseen by the American National Standards Institute and have an extremely open development process. Any industry member can submit a comment or join a committee. The standards committee can vote to revise a standards, reaffirm it without change or even withdraw it. Without standards, industry would have higher costs, more miscommunications between suppliers and customers, and delayed time to market. If you have more questions on IPC’s standards processes or would like to join a commitee, please send an e-mail to answers@Ipc.org.

        More at:
        http://www.bsieducation.org/Education/HE/about/benefits-standards.shtml
        https://blog.ipc.org/2011/03/15/standards-are-essential-for-industry/

  2. Kim Sterling
    Posted November 8, 2010 at 9:35 am | Permalink

    I’m sorry Mordechai, the technical liaison tells me the test coupon layouts are still being designed. You can find the minutes from the last meeting here: http://www.ipc.org/CommitteeDetail.aspx?Committee=1-10C


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