These standards committee reports from the 2015 Fall Standards Committee Meetings have been compiled to help keep you up to date on IPC standards committee activities. This is the third in a series of reports.
Packaged Electronic Components
The B-11 3-D Electronic Packages Subcommittee continued work on IPC-7091, Design and Assembly Process Implementation of 3-D Components. There has been significant interest in this standard from both the military and commercial markets, and the subcommittee is ensuring groups doing similar work are included in the efforts for IPC-7091.
The D-11 Flexible Circuits Design Subcommittee met to advance the Working Draft to IPC-2223D, Sectional Design Standard for Flexible Printed Boards. The group reviewed and approved new drawings depicting flexible cross-sectional construction examples and unbonded flex cross-sectional constructions for rigid-flex designs. The group also reviewed new content addressing the factors that affect impedance and capacitance control for flex and rigid-flex printed board applications so as to mitigate signal integrity issues.
The D-12 Flexible Circuits Performance Subcommittee met to advance the Working Draft to IPC-6013D, Qualification and Performance Specification for Flexible Printed Boards. The group also reviewed a cross-sectional illustrations that address voiding or delamination in the transition zone between flexible material and rigid material. The group also reviewed examples of anomalies in flexible printed board assemblies (e.g. kinks in the ribbon cable following assembly operations) and agreed to submit recommendations to the IPC 7-31b task group for addressing these issues in a future revision to IPC-A-610, Acceptability of Electronic Assemblies.
The D-13 Flexible Circuits Base Materials Subcommittee began review and updating of IPC-4202A to ultimately revise it to B revision.
The D-15 Flexible Circuits Test Methods Subcommittee began to review all flexible circuits test methods for relevance to all materials, printed boards and design standards. Most if not all test methods that apply to old flexible circuits (those that begin with “FC” are likely to be obsolete and will likely be archived.
High Speed/High Frequency
The reactivated D-22 High Speed/High Frequency Design Subcommittee met to review an initial draft of IPC-2228, Sectional Design Standard for High Frequency (RF/Microwave) Printed Boards. While agreed that the document is not intended to be used as a stand-alone document (it will support the IPC-2221B, Generic Standard on Printed Board Design), the initial draft does contain a substantial amount of “how-to 101” tutorial information for the designer as taken from the older IPC-2252, Design Guide for RF/Microwave Printed Boards. It was decided that IPC should conduct an open-ended industry survey that asks two basic questions to help steer the course of the IPC-2228:
- If a printed board fabricator switched up a job from an FR-4 board (IPC-6012) to an RF board (IPC-6018), what things would the fabricator need to focus on for that job (e.g. drilling, plating and marking)?
- What elements of fabrication and assembly are different between traditional rigid printed boards and RF printed boards that IPC should focus on (e.g. sequential lamination, back drilling and material handling)?
The D-22 High Speed/High Frequency Performance Subcommittee met to complete the process of reviewing and providing disposition to industry comments submitted during the summer 2015 Final Draft circulation of IPC-6018C, Qualification and Performance Specification for High Frequency (Microwave) Printed Boards. The document will now be prepared for official balloting and a corresponding IPC-6018CS Space and Military Avionics Applications Addendum will also be drafted for a 2016 release.
The D-24a TDR Test Methods Task Group met to review the status of the Gage R&R Validation Program for the forthcoming “B” Revision to IPC-TM-650, Method 18.104.22.168, Characteristic Impedance of Lines on Printed Boards by TDR.
The D-24b Bereskin Test Methods Task Group met to review two different industry approaches to addressing the Bereskin stripline resonator test method that lends itself to the test and measurement of Dk and Df of thin dielectric materials up to 20 GHz. An IPC-TM-650 Test Method could be developed that provides both procedures as Methods A and B.
The D-24c High Frequency Test Methods Task Group meet to review data from five participating companies in a round robin test program that will assess the state-of-the-art of test material provides and testing labs in the measurement of dielectric properties of materials at frequencies above 10 GHz. A variety of test methods are being utilized based on current practices utilized in commerce.
Rigid Printed Boards
The D-31b IPC-2221/2222 Task Group met to advance the working draft of IPC-2226A, Sectional Design Standard for HDI Printed Boards, which is the first revision effort for this standard since its original 2003 publication. Attendees were segmented into five subgroups to work on content in sections 3 through 6.
The D-33a Rigid Printed Board Performance Task Group and the 7-31a IPC-A-600 Task Group met jointly to review and approve photographs of acceptable and nonconforming anomalies for the future “J” revision to IPC-A-600, Acceptability of Printed Boards. The photographs presented were intended to address new and expanded requirements released in the new IPC-6012D, Qualification and Performance Specification for Rigid Printed Boards.
The D-35 Printed Board Storage and Handling Subcommittee met to complete the review of industry feedback to the working draft of an “A” revision to the IPC-1601, Printed Board Handling and Storage Guidelines. The group addressed comments related to measurement of moisture content, the use of oxidation arrest paper, the impact of baking on ENEPIG and ENIG surface finishes, and recommendations for resealing opened moisture barrier bags for storage of bare printed boards. A Final Draft for Industry Review will be circulated in Q4 2015.