Minutes of Meeting – 2024-06-11 – 10:00-12:00 CEST, Tokyo Japan and virtual

Participants:

Agenda:

1.        Confirmation of meeting minutes 2024-02-21

Confirmed without changes.

2.       TC91 Subjects

2.1.       General items

2.1.1     ACEA and environmental aspects within TC 91 publications

In this week various ACEA meetings take place. Reports from the meetings will be issued to LCG afterwards in preparation for the September meeting.

2.1.2     2024 & 2025 meetings

See presentation material attached.

Agenda JIC presentation meeting on June 10^th.

Actions: Ikeda san: Upload presentation materials to IEC CP and by separate email to presenters, who are not TC91 members.

2.2.       Advanced technologies projects

2.2.1     Additive manufacturing of electronics (AME)

Coordination with ISO TC 261, TC112 and IEC TC 119 as well as with IPC/ASTM activities is necessary.

In order to distinguish between “additive manufacturing” in general and in electronics, the usage of the term “On-Site Electronic (OSE)” is proposed – see presentation material circulated together with the minutes.

Preparatory work to establish a JWG between TC91 and TC112 started. Conception presented at JIC meeting on June 10^th. First project(s) have to be identified to prepare a PWI and NP. See JIC presentation.

2.2.2     Sinter technology

GNC started work on a technical report covering all aspects of sinter technology. Experts cover the whole process chain including equipment manufacturers and users.

Status: A draft is under final preparation. It is proposed to start a PWI at TC91 Fall meetings.

IPC 4922 is already published.

2.2.3 Glass substrates - -through glass vias (TGV)

R&D project in Germany is under consideration to develop manufacturing technologies for heterogenous 3D integration using TGV interposers.

Status: No further information available yet.

2.3.       High voltage applications / Insulation coordination projects

2.3.1     Test structures for voltages >100V

GNC project to develop test structures (first perhaps a TR, depending on the output from ECPE project in Germany), IPC started similar project (guideline, which considerations should be made; project is under Bob Neves).

ECPE project is up to 1000V. Project is finished. Humidity test (65°C/ 92% r.h.) is finished; testing was up to 2000 h. A second test, 1500 h with 85°C/85% r.h. is finished. A publication of the test results is expected in September. Expected output is to get information on solder mask impact to achieve a robust design. To be continued with different material and designs to get a complete picture.

IPC develops a test method for voltages from 300V to higher values (may be 3000V).
IPC-TM-650 - 2.5.7.4. High Voltage Moisture and Insulation Resistance Test of Fabricated Printed Board Test Patterns is published, gauge R&R is in progress.

2.3.2     Creepage and clearance distances on circuit boards and components

GNC started a project to develop state of the art rules for dimensioning of creepage and clearance distances on electronic assemblies, based on IEC 60664 series, IPC 2221 and OEM specifications.

Additional information: IEC 62368-1:2023, Audio/video, information and communication technology equipment - Part 1: Safety requirements contains requirements and tests for circuit boards (Annex G.13).

2.3.3     TC47 WG6 project (IEC 63492-1 ED1)

47/2773/NP “Failure mechanisms and measurement methods to evaluate solid insulation for semiconductor devices” Cooperation between the project team and TC91 as well as TC40 experts is agreed by the project leader. Contact via Walter Huck.

Status: NP is approved, many deep technical comments received, especially to clarify the scope in relation to the basic safety standard IEC 60664-1. First investigations showed that the content of IEC 60664-4 is not applicable for those materials used in higher frequency range.

According to revised project plan CD is scheduled for 2024-06.

2.3.4     Power Semiconductors for an energy-wise society

The IEC Market Strategy Board (MSB) developed a white paper, circulated as SMB/7991/DC. This comprehensive document focuses on the strategic role of power semiconductors for an energy-wise society in order to aid in establishing guidelines within standardization bodies and to bring power semiconductors to the forefront of impending standardization proposals.

A JahG led by TC47 will be formed - see 47/2852/AC.

Action: Nomination of experts via NCs (deadline is 14.6.2024). Michael Schleicher is member of the JAHG9.

Action: Close cooperation between TC91 WG3 and WG6 with TC47 WG2 and SC 47A / SC47D is necessary to cover heterogeneous integration, e.g. wide bandgap SC in power modules. Alan and Fukuba san will take care to identify best contact persons after TC47 meetings in November.

Action for WG6 and WG1: After the first results from JAHG9 are available, information shall be collected, which kind of new (embedding) technologies exist beyond described in the existing standards of the 62878 series and in IEC 62421 for electronic modules.

2.4.       Electrochemical migration / corrosion projects

First project “Qualification and test methods for coatings” is started at German NC.

Status: A PWI is under preparation to be decided at September WG3 and plenary meeting.

2.5.       Electronic module and die attach projects

Status: These projects will need a revision and to be aligned with TC47 to avoid conflicts. Still discussing this project for CD draft in JPNC.

2.6        Resistance against cleaning solvents

Project is approved and became IEC 60068-2-88. Should be closely discussed with other TCs.

Status: The project now is in CD stage (91/1908/CD; 91/1929/CC). Draft CDV discussed at WG3 meeting, CDV is scheduled for July.

2.7 Thermal design for electronic assemblies

Status: TC91 started discussion.

TC91 WG3 discussed three documents.

1.     Measurement method used in thermal design for electronics assemblies - Part 1: Measurement requirements used in thermal design for the circuit boards or assemblies with miniaturized SMDs where the heat dissipation path to the board is dominant

2.     Measurement method used in thermal design for electronics assemblies - Part 2: Measurement method for thermal conductivity of circuit boards with polymer composites

3.     Measurement method used in thermal design for electronics assemblies - Part 3: Temperature measurement method for miniaturized SMDs on circuit boards

3.       Liaison with IEC TCs

3.1.       TC40

TC91 Project “Resistance against cleaning solvent” is of high interest for TC40.

In TC 40 experts related to high voltage applications and insulation coordination are available. We can make contact when first projects are starting.

3.2.       TC47/SC47A/SC47D

3.2.1     TC47 WG6

Interesting projects on insulating materials and flexible / stretchable materials (see 47/2777/DC, IEC 62951 series). Interesting for new materials as well for PCB industry and Semiconductor industry.

3.2.2     SC47A

See report from Fukuba san.

Main theme is heterogenous integration. Joint activities between SC47A/SC47D and TC91 become necessary. Action: An ad-hoc meeting is proposed to be arranged before next meetings to discuss, which group shall take responsibility for which area and how to coordinate projects. Fukuba, Yoshida, Ikeda and Kasuga will discuss further.

3.2.3     SC47D

New projects related to thermal characterization should be studied by TC91 as well to avoid double work.

New project approved: 63378-4 Thermal evaluation of fine pitch semiconductor packages

New project related to interposer substrate, should be aligned with existing TC91 publications. To be discussed also in TC91 WG10 and WG6. Clarification of scope and terminology is necessary.

Liaison representatives need to be discussed with new SC47D chair, A. Lucero.

3.3 TC 111

Liaison representative from TC91 to TC111 needs to be re-established or to disband liaison.

New project to develop a standard for carbon footprint is delegated by IEC SMB to TC111 and ACEA

IEC 63372 ED1: Quantification and communication of Carbon Foot PRINT and GHG emission reductions/avoided emissions from electric and electronic products and systems – Principles, methodologies, requirements and guidance

Status: 111/757/CDV under voting until 2024-07-26.

3.4 TC119

Nothing to report.

3.5 TC 124

Nothing to report.

4.       Liaison with other organizations

4.1.       AEC

AEC-Q007 Initial Release (Revision -) – Board Level Reliability (BLR) Guidelines; AEC-Q007-001 Initial Release (Revision -) – BLR Temperature Cycling Test Methodology; and AEC-Q007-002 Initial Release (Revision -) – BLR Spreadsheets

Status: Publication is available from AEC Website.

4.2.       IPC

Cooperation between IPC and IEC – MoU is now under signature.

New projects see: https://www.ipc.org/Status.

J-STD 033 is under revision. It is related to IEC 61760-4 (also under revision) and should be considered carefully.

IPC CC 830 is under revision (version D). It covers coatings. Graham Naisbitt is involved in that project. Release is planned for 2025.

IPC 6921 - Requirements and Acceptance Specification for Organic IC Substrate.
 First working draft is prepared by IPC China, Taiwan and international experts. Now open for discussion.

4.3        ISO, specifically TC44 SC12 (soldering material)

ISO-9455-18: Cleanliness of soldered printed circuit assemblies before and/or after cleaning

Corrections were added in the first half of this year. Therefore, they are currently making minor adjustments to the issue before IS.

4.4.       iNEMI

Phase 3 “Conformal coating evaluation for improved environmental protection”.

Project to develop a test board to measure the effectiveness of cleaning. Evaluate thicknesses and board structure to measure protection against corrosion.

iNEMI roadmap on organic PCB material, team is established –Tarja will keep contact. Project is ongoing, some chapters will be released soon for online check. List of chapters provided by Tarja.

New projects, please see the iNEMI Website (sustainability, smart manufacturing).

4.5.       EIPC

Technical snapshot seminars are ongoing – see EIPC Webpage.

4.6.       JEDEC

4.7.       UL

Solder limits subjects still are under discussion, like selective, wave soldering. In case actual soldering profiles are available, send to Emma. There is urgent demand for information on selective soldering.

Project on requirements and testing of conformal coating of agricultural lighting is ongoing.

New project is kicked-off: New test coupon to test delamination. Information about existing designs should be sent to Emma. The existing test pattern (UL 796 Fig. 10.1) and requirements do not reflect state of the art. AT&S supports that project. Next meeting is planned in December together with FED.

5.       Others

5.1 Conferences

APEX 2025 call for participation: https://www.ipcapexexpo.org/

Pan-European design conference January 29^th to 30^th 2025 in Vienna (Austria): https://pedc.eu/; deadline for call for papers is July 31^st.

6.       Next meetings

September 25^th 13:30 – 15:30 in conjunction with TC91 fall meeting in London.