24 The PCB Magazine • November 2017
Conclusion
HDI technology continues to grow and be-
come integrated into new products. But obsta-
cles are still present for the use of this technol-
ogy in applications more complex than mobile
phones and camcorders. Solutions need to be
developed for the four remaining areas of man-
ufacturing: defining density needs; EDA tools
not providing increased functionality; process
controls for fabricating reliable microvias; and
bare-board/ICT solutions once the HDI is as-
sembled.
The opportunities for innovation abound,
with ample rewards for those looking to solve
some of today's HDI manufacturing issues.
PCB
References
1. Vardaman, Jan, TechSearch International,
acquired via private communication. Report up-
dates
available by subscription.
2. Prismark Partners, The Semiconductor
and Packaging Report, August 2017.
3. Holden, H., The HDI Handbook, I-Con-
nect007, August 2008 (free download).
4. Toshiba Inc., "New Polymeric Multilay-
er and Packaging," Conference Proceedings,
Printed Circuit World Conf. V, January 1991,
Glasgow, Scotland.
5. Frayman, Felix; Kuokka, Daniel, "A Tool
for Exploring the Solution Space of a Parame-
ter Selection Problem," Journal of Artificial In-
telligence for Engineering Design, Analysis and
Manufacturing, Cambridge University Press,
April 1995, pp 135-144.
Happy Holden has worked in
printed circuit technology since
1970 with Hewlett-Packard,
NanYa/Westwood, Merix, Foxconn
and Gentex. He is currently a con-
tributing editor with I-Connect007.
To read past columns or to contact Holden,
click here.
4
layer
HDI
board
6
layer
proto
HDI
w/test
Figure 8: Assembly testing and prototype debugging provided by two extra HDI layers that are later removed.
35 YEARS OF HDI FABRICATION PROCESSES AND OBSTACLES FOR IMPLEMENTATION
