Electronics Manufacturing Technical Articles

Investigation and Development of Tin-Lead and Lead-Free Solder Pastes to Reduce the Head-In-Pillow Component Soldering Defect.

Mar 06, 2014 | Jasbir Bath, Roberto Garcia - Christopher Associates Inc. Noriyoshi Uchida, Hajime Takahashi, Gordon Clark, Manabu Itoh - Koki Solder

Over the last few years, there has been an increase in the rate of Head-in-Pillow component soldering defects which interrupts the merger of the BGA/CSP component solder spheres with the molten solder paste during reflow. The issue has occurred across a broad segment of industries including consumer, telecom and military. There are many reasons for this issue such as warpage issues of the component or board, ball co-planarity issues for BGA/CSP components and non-wetting of the component based on contamination or excessive oxidation of the component coating. The issue has been found to occur not only on lead-free soldered assemblies where the increased soldering temperatures may give rise to increase component/board warpage but also on tin-lead soldered assemblies....

Publisher: Christopher Associates Inc.

A Novel High Thermal Conductive Underfill For Flip Chip Appliation

Feb 27, 2014 | Dr. Mary Liu and Dr. Wusheng Yin

Silicon dioxide is normally used as filler in underfill. The thermal conductivity of underfill is less than 1 w/mk, which is not able to meet the current flip chip application requirements such as 3D stacked multi-chips packaging. No matter which direction the heat will be dissipated through PCB or chip, the heat has to pass through the underfill in 3D stacked chips. Therefore the increase of thermal conductivity of underfill can significantly enhance the reliability of electronic devices, particularly in 3D package devices...

Publisher: YINCAE Advanced Materials, LLC.

Screening for Counterfeit Electronic Parts

Feb 20, 2014 | Bhanu Sood and Diganta Das

In this chapter, we discuss the type of parts used to create counterfeits and the defects/degradations inherent in these parts due to the nature of the sources they come from, proposed inspection standards, and limitations of these standards. The processes used to modify the packaging of these parts to create counterfeits are then discussed along with the traces left behind from each of the processes. We then present a systematic methodology for detecting signs of possible part modifications to determine the risk of a part or part lot being counterfeit....

Publisher: CALCE Center for Advanced Life Cycle Engineering

Why Signal Always Be Loss in a High Speed, High Frequency Transmission Line

Feb 13, 2014 | Albert Chen.

The high speed transmission applications in the electronic product become inevitable developing trend. The signal integrity becomes the most important issue in the electronics industry. The material suppliers, PCB manufacturers, OEM designers commonly face the serious issue "how to keep signal integrity operated in the high speed transmission" for the modern electronic application nowadays...

Publisher: Elite Material Co., Ltd.

Understanding SIR

Feb 06, 2014 | Chris Nash, Technical Support Engineer, Eric Bastow, Senior Technical Support Engineer; Indium Corporation.

Many electronics manufacturers perform SIR testing to evaluate solder materials and sometimes the results they obtain differ significantly from those stated by the solder material provider. The difference in the results is typically the result of SIR coupon preparation. This paper will discuss the issue of SIR coupon preparation, board cleaning techniques, and how board cleanliness directly affects SIR results....

Publisher: Indium Corporation

Going Lead Free With Vapor Phase Soldering - Lead Free Is Still a Challenge For Major Industries.

Jan 30, 2014 | Andreas Thumm

As of today, the electronic industry is aware of the requirements for their products to be lead free. All components are typically available in lead free quality. This comprises packages like BGAs with BGA solder balls to PCB board finishes like HASL. The suppliers are providing everything that is needed. It is harder to get the old tin leaded (SnPb) components for new applications today, than lead free ones.

So why has not everybody changed over fully yet and how can the challenges be overcome?

A big concern in this transition process is reflow soldering. The process temperatures for lead free applications became much higher. Related with this is more stress for all the components. It affects the quality and reliability of the electronic units and products......

Publisher: IBL - Löttechnik GmbH

Testing Intermetallic Fragility on Enig upon Addition of Limitless Cu

Jan 23, 2014 | Martin K. Anselm, Ph.D. and Brian Roggeman Universal Instruments Corp.

As reliability requirements increase, especially for defense and aerospace applications, the need to characterize components used in electronic assembly also increases. OEM and EMS companies look to perform characterizations as early as possible in the process to be able to limit quality related issues and improve both assembly yields and ultimate device reliability. In terms of BGA devices, higher stress conditions, RoHS compatible materials and increased package densities tend to cause premature failures in intermetallic layers. Therefore it is necessary to have a quantitative and qualitative test methodology to address these interfaces....

Publisher: Universal Instruments Corporation

Advanced Rework Technology and Processes for Next Generation Large Area Arrays, 01005, PoP and QFN Devices.

Jan 16, 2014 | Brian Czaplicki, Director, Technical Marketing Programs, Air Vac Engineering Co., Inc.

BGA Rework is now largely mature, although new supplemental processes that provide improved process control such as Solder Paste Dipping and Non-Contact Site Cleaning can now be integrated into existing processes if the rework technology that is used allows. So what are the next set of challenges that will need to be addressed in regard to Area Array and SMT Rework? The International Electronics Manufacturing Initiative or iNEMI has recently published its 2013 Technology Roadmap for the global electronics industry which includes a section dedicated specifically to rework and repair. Of particular interest and importance is iNEMI’s gap analysis which identifies future specific gaps and challenges that will result from such factors as government regulations, disruptive technologies and new product requirements....

Publisher: Air-Vac Engineering Co., Inc.

Embedded Passive Technology

Jan 09, 2014 | Hikmat Chammas

Embedded Passive Technology is a viable technology that has been reliably used in the defense and aerospace industry for over 20 years. Embedded Passive (Resistors and Capacitors) Technology have a great potential for high frequency and high density applications. It also provides better signal performance, reduced parasitic and cross talk. This paper summarizes the selection of resistor embedded materials, evaluations of resistive material (Phase 1) and duplication of a complex digital design (Phase 2). Phase 1 –resistive materials (Foil 25Ω/sq NiCr and 1kΩ/sq CrSiO) and resistive-Ply materials (25Ω/sq and 250Ω/sq NiP) were chosen for evaluation....

Publisher: Honeywell International

Thermal Shock and Drop Test Performance of Lead-free Assemblies with No-Underfill and Corner-Underfill

Jan 02, 2014 | Bankeem Chheda and S. Manian Ramkumar, Ph.D.; Rochester Institute of Technology-CEMA, Reza Ghaffarian; Ph.D. Jet Propulsion Laboratory.

With ROHS compliance the transition to lead-free is inevitable. Several lead-free alloys are available in the market and its reliability has been the main concern. The results from this experimental research aims at making a comparison of different lead-free alloy combinations. Thermal shock and drop tests are a part of this experimental study....

Publisher: Jet Propulsion Laboratory