JANUARY 2025 I PCB007 MAGAZINE 77
Happy Holden has worked
in printed circuit technolo-
gy since 1970 with Hewlett-
Packard, NanYa Westwood,
Merix, Foxconn, and
Gentex. He is currently a
contributing technical
editor with I-Connect007,
and the author of Automa-
tion and Advanced Procedures in PCB Fabrication,
and 24 Essential Skills for Engineers. To read past
columns, click here.
Figure 2: Ventec's new RCC properties and the graph of some of these materials as a function
of dielectric loss vs. Z-axis CTE. (Source: SMTA UHDI Symposium & SMTAI Pavilion)
Summary
e need for UHDI programs is great. I saw
this need at the IPC High Density PWB Con-
ference at IPC APEX EXPO 2024, and SMTA's
UHDI Pavilion last October. e next step is
to tie our HDI and UHDI manufacturing pro-
cesses to the new IPC HDI design standards
and IPC UHDI design standards. PCB007
References
1. The HDI Handbook, Chapter 5, "HDI Materials."
2. SMTA 2024 Technical Knowledge, UHDI Sympo-
sium (April 2024) and UHDI Pavilion (October 2024)
3. "Happy's Tech Talk #29: Semi-flex FR-4s," by
Happy Holden, PCB007 Magazine, May 2024.
