Laser Patterning & Metallization to Reduce Process Steps for PCB Manufacturing


Reading time ( words)

Abstract

Glass offers a number of advantages as a dielectric material, such as a low coefficient of thermal expansion (CTE), high dimensional stability, high thermal conductivity and suitable dielectric constant. These properties make glass an ideal candidate for, among other things, package substrate and high-frequency PCB applications. We report here a novel process for the production of printed circuit boards and integrated circuit packaging using glass as both a dielectric medium and a platform for wiring simultaneously.

An ultrafast laser is used to etch away the desired pattern (pads, wires and vias) in the glass, and copper plating is “seeded” through the laser-based deposition of copper droplets. The seeded area is then plated using electroless plating followed by electroplating. Demonstrations of fine pitch wires, variable diameter through holes and blind vias, and a multilayer stack are shown. The deposits have a resistivity less than a factor of 1.5x that of bulk copper for 5-10 mm wires. Plated lines in borosilicate glass of 7-10 μm width and 5-20 μm depth and line spacing down to ~10 μm are demonstrated, as well as vias with a top diameter approaching 100 μm for 150 μm glass and 40 μm for 50 μm glass.

The process presents the potential for significant material savings in terms of base materials, process chemicals, and waste disposal/recycling costs (glass is on the order of 100-fold less expensive than some current high-frequency dielectrics, and wet processes account for a large part of standard PCB/substrate manufacturing). Additionally, the processes are amenable toward other dielectric materials such as FR-4, polyimide and PTFE-based materials.

Introduction

Increased demand for high data transmission rates is driving the development of smaller PCB features. Electrical circuits are reaching the physical limitations of traditional PCB dielectric materials under which electromagnetic compatibility can be controlled.

To read the full version of this article which appeared in the August 2017 issue of The PCB Magazine, click here.

Share


Suggested Items

Weiner’s World—August 2017

09/04/2017 | Gene Weiner, Weiner International Inc.
IPC is planning to hold a special meeting on automotive electronics for senior executives during IPC APEX EXPO 2019. The meeting will be planned and produced by the IPC Ambassador Council. Its presentations will feature senior members of the entire automotive electronics supply chain.

Mr. Laminate Tells All: PTFE is About to be Banned by IEC TC111

07/10/2017 | Doug Sober, Essex Technologies Group, with Stephen Tisdale, Tisdale Environmental Consulting LLC
There, I said it. Technical Committee 111 of the International Electrotechnical Commission (IEC) is preparing to effectively ban PTFE (polytetrafluoroethylene) materials from electronics. As history goes, the electronics industry has focused on only two of the four halogens (bromine and chlorine) to be limited in order to be called “halogen-free” or more accurately “low-halogen.” But now, fluorine is being dragged down too, just because of its location in the periodic table.

Better Together: How HDP User Group Showcases the Industry’s Best Side

06/21/2017 | Barry Matties, I-Connect007
HDPUG is a non-profit trade organization comprised of members from top companies in the electronics industry, from materials suppliers and manufacturers, to OEMs and end users. Key activities include collaborating on issues facing multiple industries and bringing people together on projects who might not have met otherwise. Barry Matties met HDPUG’s European representative and project facilitator Alun Morgan at the recent EIPC Summer Conference to learn more about the group and current projects.



Copyright © 2018 I-Connect007. All rights reserved.