Electronics Manufacturing Technical Articles

An Investigation Into The Durability Of Stencil Coating Technologies

Mar 13, 2019 | Greg Smith, Tony Lentz

It is well documented that Nano coatings on SMT stencils offer many benefits to those assembling PWBs. With reduced standard deviation and improved transfer efficiency nano coatings can provide, there is also a cost. As PWB assemblers work to justify the return on investment, one key question continues to arise. What is the durability or life of these coatings and what can be done in the print process to maximize the life of the coatings?

This paper addresses durability of the coatings in relation to the number of print cycles and underside wipe cycles applied as well as materials used on the underside wipe process. Different parameters will be applied and data will be collected. The results of this study will be summarized to help those using or considering the use of these nano coatings to improve their print process and suggestions will be given to maximize the life of the coatings....

Publisher: FCT ASSEMBLY, INC.

Effect of Encapsulation Materials on Tensile Stress during Thermo-Mechanical Cycling of Pb-Free Solder Joints

Mar 06, 2019 | Maxim Serebreni, Dr. Nathan Blattau, Dr. Gilad Sharon, Dr. Craig Hillman

Electronic assemblies use a large variety of polymer materials with different mechanical and thermal properties to provide protection in harsh usage environments. However, variability in the mechanical properties such as the coefficient of thermal expansion and elastic modulus effects the material selection process by introducing uncertainty to the long term impacts on the reliability of the electronics. Typically, the main reliability issue is solder joint fatigue which accounts for a large amount of failures in electronic components. Therefore, it is necessary to understand the effect of polymer encapsulations (coatings, pottings and underfills) on the solder joints when predicting reliability.

This paper presents the construction and validation of a thermo-mechanical tensile fatigue specimen. The thermal cycling range was matched with potting expansion properties in order to vary the magnitude of tensile stress imposed on solder joints...

Publisher: DfR Solutions (acquired by ANSYS Inc)

Evaluation, Selection and Qualification of Replacement Reworkable Underfill Materials

Feb 27, 2019 | Jeffrey Colish, Luis Lopez, Carlo Viola

A study was performed to investigate, evaluate and qualify new reworkable underfill materials to be used primarily with ball grid arrays (BGAs), Leadless SMT devices, QFNs, connectors and passive devices to improve reliability. The supplier of the sole source, currently used underfill, has indicated they may discontinue its manufacture in the near future. The current underfill material is used on numerous circuit card assemblies (CCAs) at several sites and across multiple programs/business areas. In addition, it is used by several of our contract CCA suppliers.

The study objectives include evaluation of material properties for down select, dispensability and rework evaluation for further down select, accelerated life testing for final selection and qualification; and process development to implement into production and at our CCA suppliers. The paper will describe the approach used, material property test results and general findings relative to process characteristics and rework ability....

Publisher: Northrop Grumman Corporation

The Influence of Clean Air on the Value-Added Chain in Electronics Production

Feb 25, 2019 | ULT

"The idea of the value chain is based on the process view of organizations, the idea of seeing a manufacturing (or service) organization as a system, made up of subsystems each with inputs, transformation processes and outputs".[1] The definition of a value-added chain by Michael E. Porter is one of many to be found in reference books, works and on websites. In principle, it involves a sequence of activities, executed by a manufacturing company to develop, produce, sell, ship, and maintain products or services. Three main parameters essentially influence a value-added chain: Direct activities − research, development, production, shipment etc. Indirect activities − maintenance, operation, occupational safety, environment etc. Quality assurance − monitoring, test/inspection; quality management etc. In particular, indirect activities and quality assurance generate a greater part of the costs in product manufacturing. This article principally focusses on the indirect activities, among them air purification....

Publisher: ULT Canada Sales Incorporated

The Impact of New Generation Chemical Treatment Systems on High Frequency Signal Integrity

Feb 20, 2019 | Jim Fuller, Sanmina-SCI; Karl Sauter, Oracle Corporation; Scott Hinaga, Cisco; Tian Qingshan, Huawei; John J Davignon, HDP User Group; Brian Butler, Introbotix; Ted Antonellis, Michael Coll, John Marshall, John Marshall, MacDermid Enthone; Joseph Smetana,

The High Density Packaging (HDP) User Group has completed a project evaluating the high frequency loss impacts of a variety of imaged core surface treatments (bond enhancement treatments, including chemical bonding and newer low etch alternative oxides) applied just prior to press lamination. Initial high frequency Dk/Df electrical test results did not show a strong correlation with any of the methods utilized within this project to measured surface roughness. The more significant factor affecting the measured loss is the choice of pre-lamination surface treatment. Most of the new chemical treatment systems outperform the older existing systems which depend upon surface roughness techniques to promote adhesion....

Publisher: Sanmina-SCI

Influence of Copper Conductor Surface Treatment for High Frequency PCB on Electrical Properties and Reliability

Feb 13, 2019 | Seiya Kido, Tsuyoshi Amatani

Development of information and telecommunications network is outstanding in recent years, and it is required for the related equipment such as communication base stations, servers and routers, to process huge amount of data in no time. As an electrical signal becomes faster and faster, how to prevent signal delay by transmission loss is a big issue for Printed Circuit Boards (PCB) loaded on such equipments. There are two main factors as the cause of transmission loss; dielectric loss and conductor loss. To decrease the dielectric loss, materials having low dielectric constant and low loss tangent have been developed. On the other hand, reducing the surface roughness of the copper foil itself to be used or minimizing the surface roughness by modifying surface treatment process of the conductor patterns before lamination is considered to be effective in order to decrease the conductor loss. However, there is a possibility that reduction in the surface roughness of the conductor patterns will lead to the decrease in adhesion of conductor patterns to dielectric resin and result in the deterioration of reliability of PCB itself.

In this paper, we will show the evaluation results of adhesion performance and electrical properties using certain type of dielectric material for high frequency PCB, several types of copper foil and several surface treatment processes of the conductor patterns. Moreover, we will indicate a technique from the aspect of surface treatment process in order to ensure reliability and, at the same time, to prevent signal delay at the signal frequency over 20 GHz. ...

Publisher: MEC Company Ltd.

Anti static IC shipping tube customization guidelines

Feb 07, 2019 | James tong

Antistatic plastic IC shipping tube customization, need to provide the following four aspects of information: First, the choice of pipe material; Second, the size of the parts or physical; Third, the length of the pipe; Fourth, the choice of plug....

Publisher: Shenzhen Sewate Technology Co.,Ltd

High Frequency Dk and Df Test Methods Comparison High Density Packaging User Group (HDP) Project

Feb 06, 2019 | Karl Sauter

The High Density Packaging (HDP) user group has completed a project to evaluate the majority of viable Dk (Dielectric Constant)/Df (Dissipation Factor) and delay/loss electrical test methods, with a focus on the methods used for speeds above 2 GHz. A comparison of test methods from 1 to 2 GHz through to higher test frequencies was desired, testing a variety of laminate materials (standard volume production with UL approval, low loss, and "halogen-free" laminate materials). Variations in the test board material resin content/construction and copper foil surface roughness/type were minimized. Problems with Dk/Df and loss test methods and discrepancies in results are identified, as well as possible correlations or relationships among these higher speed test methods....

Publisher: Oracle Corporation

Adapting Wave Soldering to High-Flexibility Manufacturing

Feb 05, 2019 | Bennett Bruntil, VP, Sono-Tek Corp

SonoFlux Servo with InSight automated board recognition system helps PCB manufacturers take steps toward greater automation and traceability and the goal of Industry 4.0....

Publisher: SONO-TEK CORPORATION

Novel Pogo-Pin Socket Design for Automated Low Signal Linearity Testing of CT Detector Sensor

Jan 30, 2019 | Mahesh Narayanaswamy

Due to the arrayed nature of the Computed Tomography (CT) Detector, high density area array interconnect solutions are critical to the functionality of the CT detector module. Specifically, the detector module sensor element, hereby known as the Multi-chip module (MCM), has a 544 position BGA area array pattern that requires precise test stimulation. A novel pogo-pin block array and corresponding motorized test socket has been designed to stimulate the MCM and acquire full functional test data. (...) This paper and presentation will focus on the socket design challenges and also key learnings from the design that can be applied to general test systems, including reliability testing. The secondary focus will be on the overall data collection and graphical user interface for the test equipment....

Publisher: General Electric