Conductive Inks

“Advances in Conductive Inks across Multiple Applications and Deposition Platforms”

Authors: Scott E. Gordon, Jay R. Dorfman, Daniel Kirk and Kerry Adams; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
Abstract: It has been only in recent years that the term printed electronics, with the inherent benefits of low-cost manufacturing using additive processing, has captured the attention of a much wider audience. One consequence of this attention has been the rush to invest in new materials and patterning processes. While the results so far have generated some as yet unrealized market hype, many new and emerging applications are just entering into production. But instead of requiring radical changes, many of these applications are using screen-printed conductive materials that are fundamentally similar to those materials that have been used for over 30 years. We present here a review of both traditional and emerging applications for printed electronics, with a focus on the printed functional materials. We also present several recent advances in the capabilities of conductive inks for various deposition methods. (IPC Apex Expo, February 2012)
Hole Plating

“Any Layer Via Interconnects Using Sintered Paste for Mobile Electronics”

Author: James Haley
Abstract: Tremendous capital expenditures are required to meet smartphone PCB demand by plating alone. Sintering paste requires less capital equipment vs. plating. Moreover, whereas a single plating line can cost $2 million to $3.6 million, a screen printer required for the paste process is $200,000 to 300,000, and the printer capacity can be equivalent to several plating lines. (IPC Apex Expo, February 2012)

Laminates

“Thermal Characteristics of PCB Laminates used in High Frequency Applications”

Author: John Coonrod; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
Abstract: There are many different aspects to consider for PCB thermal management. This paper investigates thermal management issues of high-frequency PCBs as they relate to material properties, insertion loss and circuit design configurations. It shows tradeoffs between these aspects that can be very beneficial for the circuit designer to be aware of. Among the considerations are material properties, insertion loss and circuit design. (IPC Apex Expo, February 2012)

Quality Assurance

“Before & After Reflow Characterization of FCBGA Voiding Utilizing High Resolution CT Scan, X-ray (2D & 3D) Imaging, and Cross Section with Digital Imaging”

Authors: Gordon O’Hara, Matthew Vandiver, Jonathan Crilly and Nick Brinkhoff; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
Abstract: A joint project between Flextronics and North Star Imaging was conducted to correlate current x-ray imaging and cross-section analysis of BGA voiding with state-of-the-art high-resolution CT scan imaging. Our primary objective was to validate the void measurements obtained from nondestructive imaging techniques, with the physically measured void measurements of cross-sectioning. A secondary goal was to characterize void properties before and after reflow. Typical AXI equipment provides one to three horizontal planes of reference for BGA void measurements. CT scan imaging provides a full 3D volumetric representation of the BGA void, allowing for size, volume and void position data, information that can be used in failure analysis and process characterization projects without physical destruction of the printed circuit board. Five 50mm FCBGA devices and five 52.5mm FCBGA devices, with known voiding, were used in the study. The voiding for each device was measured on a 3D AXI, a 2D off-axis high resolution x-ray and CT scan system. The devices then were placed on printed circuit boards and reflowed. After reflow, all voiding was measured again using each piece of equipment. In addition, select voids were cross-sectioned, polished and measured using a high-magnification digital microscope and correlated to the other x-ray imaging tools. (IPC Apex Expo, February 2012)