Electronics Manufacturing Technical Articles

Stencil Design for Lead-Free SMT Assembly

Mar 05, 2018 | Chrys Shea

In order to comply with RoHS and WEEE directives, many circuit assemblers are transitioning some or all of their soldering processes from tin-lead to lead-free within the upcoming year. There are no drop-in replacement alloys for tin-lead solder, which is driving a fundamental technology change. This change is forcing manufacturers to take a closer look at everything associated with the assembly process: board and component materials, logistics and materials management, solder alloys and processing chemistries, and even soldering methods.

Do not expect a dramatic change in soldering behavior when moving to lead-free solders. The melting points of the alloys are higher, but at molten temperatures the different alloys show similar behaviors in a number of respects. Expect subtler changes, especially near the edges of a process window that is assumed based on tin-lead experience rather than defined through lead-free experimentation. These small changes, many of them yet to be identified and understood, will manifest themselves with lower assembly yields. The key to keeping yields up during the transition to lead-free is quickly learning what and where the subtle distinctions are, and tuning the process to accommodate them....

Publisher: Cookson Electronics

Troubleshooting SMT Solder Paste Problems

Mar 05, 2018 | Heraeus

Troubleshooting SMT Solder Paste Problems...

Publisher: Heraeus

Deposition of Solder Paste into High Density Cavity Assemblies

Feb 28, 2018 | Fernando Coma, Jeffrey Kennedy, Thilo Sack

Circuit functional density requirements continue to drive innovative approaches to high performance packaging. Some new approaches include; aggressive space reduction, embedded solutions, and those that offer some form of risk reduction and rework potential are now options that are being explored by customers. Requirements for assembly of these types of packages necessitate the deposition of solder paste and assembly of components into cavities of the substrates to gain z-axis density as well as area functional density. Advances in the fabrication of PWB’s with cavities using newly developed laser micro-fabrication processes along with increased circuit pitch density of 50 micron lines and spaces permit new applications for high performance electronic substrates.

First published at SMTA Pan Pacific Symposium...

Publisher: Celestica Corporation

Hand Soldering with Lead Free Alloys

Feb 22, 2018 | Metcal

As companies start to implement lead free soldering processes, hand soldering and associated techniques have been identified as key functions in the manufacturing process requiring additional research and development. Hand soldering tends to occur at the end of the process line where the circuit board has a high intrinsic value and so correct process control will have a significant affect on manufacturing costs and productivity.

This paper discusses the fundamental aspects of the hand soldering process and discusses process adaptation requirements for successful lead free implementation....

Publisher: Metcal

Making a Rigid Industry More Flexible

Feb 21, 2018 | Tuan Tran

Flex Circuits and Rigid-Flex Boards Are Taking Off...

Publisher: Power Design Services

What Makes Flex Circuit Assembly Different?

Feb 18, 2018 | Tuan Tran

Flex circuits allow manufacturers to be more creative than ever....

Publisher: Power Design Services

Design Rules For Selective Soldering Assemblies

Feb 14, 2018 | Vitronics Soltec Oosterhout

This document describes general guidelines and attention points for PCB design regarding selective soldering. The guidelines can be applied for Select Wave and/or Multi Wave soldering process in both leaded and leadfree alloy. When a PCB is designed according to these guidelines, a stable and solid solder-process can be guaranteed....

Publisher: Vitronics Soltec

Mixed Voltages And Aluminum Conductors: Assesing New Electrcal Technology

Feb 07, 2018 | Olivier Neuman

The architecture of vehicle electrical systems is changing rapidly. Electric and hybrid vehicles are driving mixed voltage systems, and cost pressures are making conductor materials like aluminum an increasingly viable competitor to copper.

This paper presents tradeoff studies at the vehicle level, and how to automatically generate an electrical Failure Mode Effects and Analysis (FMEA) report, as well as how to optimize wire sizes for both copper and aluminum at the platform level....

Publisher: Mentor Graphics

Electronic Does Not Equal Smart: Service Documentation and Brand Quality

Feb 01, 2018 | Muhammad Askar

This paper briefly summarizes the technologies underpinning the evolution in electrical system diagnosis and repair, which include schematic layout automation using prototypes and rule-based styling, instant language translation, 2D/3D view links with schematics, interactive diagnostic procedures, and dynamically-generated signal-tracing diagrams. These technologies empower after-sales service teams with state-of-the-art capabilities, which not only reduce costs but also improve brand quality in the eyes of its customers. ...

Publisher: Mentor Graphics

Fine Pitch Cu Pillar with Bond on Lead (BOL) Assembly Challenges for High Performance Flip Chip Package

Jan 17, 2018 | Nokibul Islam, Vinayak Pandey, KyungOe Kim

Fine pitch copper (Cu) Pillar bump has been growing adoption in high performance and low-cost flip chip packages. Higher input/output (I/O) density and very fine pitch requirements are driving very small feature sizes such as small bump on a narrow pad or bond-on-lead (BOL) interconnection, while higher performance requirements are driving increased current densities, thus assembling such packages using a standard mass reflow (MR) process and maintaining its performance is a real and serious challenge. (...)

In this study a comprehensive finding on the assembly challenges, package design, and reliability data will be published.

Originally published in the SMTA International 2016...

Publisher: STATS ChipPAC Inc