Reading time ( words)
These standards committee reports from the 2014 Fall Standards Committee Meetings have been compiled to help keep the industry up to date on IPC standards committee activities. This is the second in a series of reports.
The 3-11 Laminate/Prepreg Materials Subcommittee successfully revised, balloted and released IPC-4101D, Specification for Base Materials for Rigid and Multilayer Printed Boards in April 2014. Shortly after this, a few company members brought up some details in the released version that they believe requires an Amendment modification to the D revision. This took up more than 75% of the meeting to discuss and decide the items to be covered in an amendment to IPC-4101D. The other 20 to 25% of the meeting involved distributing hard copies of IPC-4101D to the 3-11 Subcommittee members listed in the document’s Acknowledgement Page.
The 3-11f UL/CSA Task Group discussed upcoming items for ballot by the STP members in the UL 796 standard for rigid or multilayer printed boards. The group went through nearly two dozen items for comment in UL 746E Ballot by the STP group on these items in this UL standard will begin shortly.
The 3-11g Corrosion of Metal Finishes Task Group reviewed the status of mixed flowing gas testing of various metal finishes for corrosion on component leads as well as printed board surfaces. Flowers of Sulfur (FoS) corrosion testing was also reviewed during the meeting.
The 3-12a Metallic Foil Task Group addressed some round-robin data results using the non-contact surface roughness test (proposed TM 2.2.22). While data is only available from three of six test facilities, data is trending to show reasonable surface roughness information.
The 3-12d Woven Glass Reinforcement Task Group examined weave size data for four weave styles (106, 1080, 2116, and 7629) measured in a round robin test format by four test facilities. Statistical analysis (Gauge R & R) of the test data was not as consistent as hoped, but was showing adequate viability of the test procedure used by the four test companies. More testing is needed.
The 4-14 Plating Processes Subcommittee reviewed revision A efforts underway on IPC-4552, Specification for Electroless Nickel/Immersion Gold (ENIG) Plating for Printed Circuit Boards. The group is using the released copy of IPC-4556, Specification for Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG) Plating for Printed Circuit Boards as a template. Some of the items to be included in the revision A were discussed: a) Work on a test vehicle to evaluate a thinner gold plate for performance, b) Other work on evaluating hypercorrosion of the electroless nickel when the immersion gold is deposited, c) A test method being developed to measure the phosphorus content in the nickel is nearly completed, and d) In order to analyze the phosphorus content of the underlying nickel, two test methods to strip the gold overplate are in development.
Assembly and Joining
The 5-11c Electronic Assembly Adhesives Task Group is approaching final draft status for a new document, IPC-HDBK-4691, Guidelines for Design, Selection, Application, and Reliability of Adhesives and Associated Processes Used for Electronics Assembly Purposes (working title). Publication target: 1 Q 2015.
The 5-21g Flip Chip Mounting Task Group is preparing revision A of IPC-7094, Design and Assembly Process Implementation for Flip Chip and Die Size Components. The committee confirmed 7094 will not contain new packaging concepts of 2.5 and 3-D package configurations (addressed separately in a, IPC-7091 byB-11 Subcommittee). To facilitate that separate approach, a limited-scope (fast-track) revision of 7094A is planned, primarily for the addition of ultra-fine-line, copper pillar, and bump-on-trace (BOT) technologies, to free up some of the shared resources for the larger, more complex IPC- 7091 effort. Target publication of 7094A is expected by 2016 IPC APEX Expo.
The 5-21k IPC-SM-817 SMT Adhesive Task Group completed follow-up on comments received on the Final Industry Review circulation of IPC-SM-817A, General Requirements for Dielectric Surface Mounting Adhesives. The document will now be balloted.