Electronics Manufacturing Technical Articles

Papers and articles related to SMT, PCB & EMS industry.

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1757 SMT / PCB Assembly Related Technical Articles

Autonomous Driving - New systems to optimally apply potting media

Oct 17, 2019 | Scheugenpflug

There has been an increase in sealing and encapsulation applications mainly in the field of autonomous driving. Safety and assistance systems already make driving safer and more comfortable today. With increasing progress even more electronic systems will be added. The smooth functioning of computers, sensors, cameras, etc. - and thus our safety as road users - also depends on optimally applied potting media. These can be applied economically, quickly and with high quality in individual applications and are now mastered. With the changing mobility concepts, however, the prerequisites in manufacturing are changing. The requirements are often not fixed at the outset, but only develop during the course of the project. The aim here is to generate a flexible standard that enables attractive pricing and short delivery times. However, we are prepared for these developments: with our modular system consisting of scalable system modules. From this, individual processes can be taken and combined according to requirements. Our new LiquiPrep systems have recently become part of this modular system. They represent a further development of the proven A310 product family and enable reliable processing and conveying of self-levelling media. In addition to a significantly more intuitive operation, the LiquiPrep systems also offer higher performance thanks to a new, patented membrane pump and an optimized agitator. Image: Optimally applied sealants and casting materials form the basis for high quality and smooth functioning of the components. ...

Publisher: Scheugenpflug Inc.

Scheugenpflug Inc.

Producer of bonding, dispensing and potting solutions with outstanding expertise in automation. As part of the Atlas Copco Group, we have a worldwide sales & service network and access to the Group's extensive technology portfolio

Kennesaw, Georgia, USA

Manufacturer

Effect Of Voids On Thermo-Mechanical Reliability of Solder Joints

Oct 16, 2019 | Morgana Ribas, Ph.D., Siuli Sarkar, Ph.D., Carl Bilgrien, Ph.D., Tom Hunsinger - Alpha Assembly Solutions, MacDermid Performance Solutions

Despite being a continuous subject of discussion, the existence of voids and their effect on solder joint reliability has always been controversial. In this work we revisit previous works on the various types of voids, their origins and their effect on thermo-mechanical properties of solder joints. We focus on macro voids, intermetallics micro voids, and shrinkage voids, which result from solder paste and alloy characteristics. We compare results from the literature to our own experimental data, and use fatigue-crack initiation and propagation theory to support our findings. Through a series of examples, we show that size and location of macro voids are not the primary factor affecting solder joint mechanical and thermal fatigue life. Indeed, we observe that when these voids area conforms to the IPC-A-610 (D or F) or IPC-7095A standards, macro voids do not have any significant effect on thermal cycling or drop shock performance....

Publisher: Alpha Assembly Solutions

Alpha Assembly Solutions

Alpha Assembly Solutions is a world leader in the development, manufacturing, and sales of innovative materials used in the assembly electronics, industrial joining and Photo Voltaic market places.

South Plainfield, New Jersey, USA

Manufacturer

Advanced Packaging Technology

Oct 16, 2019 | ACI Technologies, Inc.

A major goal of the development of advanced packaging technology is to reduce the size, weight, and power consumption of electronics components using state-of-the-art commercial technologies. One of the novel concepts involves the use of all three spatial dimensions when designing and producing new systems. In the past, electronic structures tended to be two dimensional in nature. Generally speaking, individually packaged integrated circuit (IC) dies were interconnected on printed circuit boards. Techniques such as die and package stacking naturally contribute to a reduction of the spatial footprint of any given electronic system design. ...

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

ACI, an authorized IPC Training Center operating the National Electronics Manufacturing Center of Excellence providing analytical testing, manufacturing and repair services to the electronics industry.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

Fill the Void IV: Elimination of Inter-Via Voiding

Oct 10, 2019 | Tony Lentz - FCT Assembly, Greg Smith - BlueRing Stencils

Voids are a plague to our electronics and must be eliminated! Over the last few years we have studied voiding in solder joints and published three technical papers on methods to "Fill the Void." This paper is part four of this series. The focus of this work is to mitigate voids for via in pad circuit board designs. Via holes in Quad Flat No-Lead (QFN) thermal pads create voiding issues. Gasses can come out of via holes and rise into the solder joint creating voids. Solder can also flow down into the via holes creating gaps in the solder joint. One method of preventing this is via plugging. Via holes can be plugged, capped, or left open. These via plugging options were compared and contrasted to each other with respect to voiding. Another method of minimizing voiding is through solder paste stencil design. Solder paste can be printed around the via holes with gas escape routes. This prevents gasses from via holes from being trapped in the solder joint. Several stencil designs were tested and voiding performance compared and contrasted. In many cases voiding will be reduced only if a combination of mitigation strategies are used. Recommendations for combinations of via hole plugging and stencil design are given. The aim of this paper is to help the reader to "Fill the Void."...

Publisher: FCT ASSEMBLY, INC.

FCT ASSEMBLY, INC.

With numerous facilities in the United States, we are one of the electronics industry's leading manufacturers of lead-free solder products, superior quality stencils, and precision cut parts.

Greeley, Colorado, USA

Manufacturer

Power Interfaces

Oct 07, 2019 | ACI Technologies, Inc.

Power interfaces are required when external power sources like solar panels, fuel cells, or batteries are used to generate power for electrical devices. There are two major power interfaces commonly used, direct current to direct current (DC/DC) converters and direct current to alternating current (DC/AC) inverters. While both interfaces are designed to convert from variable DC inputs, they output to different power standards and power levels that are used in different applications....

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

Effects of Temperature Uniformity on Package Warpage

Oct 03, 2019 | Neil Hubble, Charly Olson

Knowing how package warpage changes over temperature is a critical variable in order to assemble reliable surface mount attached technology. Component and component or component and board surfaces must stay relatively flat with one another or surface mount defects, such as head-in-pillow, open joints, bridged joints, stretched joints, etc. may occur. Initial package flatness can be affected by numerous aspects of the component manufacturing and design. However, change in shape over temperature is primarily driven by CTE mismatch between the different materials in the package. Thus material CTE is a critical factor in package design. When analyzing or modeling package warpage, one may assume that the package receives heat evenly on all sides, when in production this may not be the case. Thus, in order to understand how temperature uniformity can affect the warpage of a package, a case study of package warpage versus different heating spreads is performed.Packages used in the case study have larger form factors, so that the effect of non-uniformity can be more readily quantified within each package. Small and thin packages are less prone to issues with package temperature variation, due to the ability for the heat to conduct through the package material and make up for uneven sources of heat. Multiple packages and multiple package form factors are measured for warpage via a shadow moiré technique while being heated and cooled through reflow profiles matching real world production conditions. Heating of the package is adjusted to compare an evenly heated package to one that is heated unevenly and has poor temperature uniformity between package surfaces. The warpage is measured dynamically as the package is heated and cooled. Conclusions are drawn as to how the role of uneven temperature spread affects the package warpage....

Publisher: Akrometrix

Akrometrix

Leading provider of full-field metrology solutions for substrates and packages in the OEM/CEM/SATS/PCB segments of the microelectronics industry.

Atlanta, Georgia, USA

Consultant / Service Provider, Manufacturer

Cleanliness/Corrosion Mitigation

Sep 27, 2019 | ACI Technologies, Inc.

One of the most critical factors in preventing corrosion from occurring in electronics is maintaining the state of cleanliness. This is not an easy feat to achieve. Corrosion is defined as the deterioration of a material or its properties due to a reaction of that material with its chemical environment. [1] So, to prevent corrosion from occurring, either the material or the chemical environment must be adjusted. Adjusting the material usually means application of a protective coating or replacing a more reactive material with a less reactive material. Adjusting the chemical environment usually means removing ionic species through cleaning, and removing moisture, usually with a conformal coating or hermetic package. Ionic species and moisture are problematic because they form an electrolyte which is able to conduct ions and electricity. Any metal that comes into contact with the electrolyte can begin to corrode....

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

What is the main function of hot air dry oven?

Sep 25, 2019 | climatest symor

What is the main function of hot air dry oven? Drying ovens are devices used to remove moisture and other solvents from the items placed inside them through a forced convection process, collecting it elsewhere so that the object becomes dehydrated. A drying oven causes objects to dry out through evaporation. Drying ovens use convection heating,also called air forced, in which the object is heated through air currents. Water from the object escapes into the air, raising the humidity level and causing the semi-solid membranes inside the oven to absorb the water. The end result is that the oven removes water from the object being dried, leaving it dehydrated. Drying ovens contain a system for forcing convection currents to develop, usually either a fan or turbine, which aids in the heating and drying process by ensuring that the hot air circulates,many ovens are equipped with an adjustable ventilation system that allows the user to ensure that the system has an adequate air supply. For details,pls visit our website: https://climatechambers.com/articles&latestnews/what-is-the-main-function-of-hot-air-dry-oven.html...

Publisher: Symor Instrument Equipment Co.,Ltd

Symor Instrument Equipment Co.,Ltd

Climatest Symor® is the leading environmental simulation testing equipment manufacturer in China established in 2001, located at Dayang Industrial Park,Hefei,China.

Hefei, China

Manufacturer

Thermal Capabilities of Solder Masks and Other Coating Materials - How High Can We Go?

Sep 24, 2019 | Sven Kramer

This paper focuses on three different coating material groups which were formulated to operate under high thermal stress and are applied at printed circuit board manufacturing level. While used for principally different applications, these coatings have in common that they can be key to a successful thermal management concept especially in e-mobility and lighting applications. The coatings consist of: Specialty (green transparent) liquid photoimageable solder masks (LPiSM) compatible with long-term thermal storage/stress in excess of 150°C. Combined with the appropriate high-temperature base material, and along with a suitable copper pre-treatment, these solder resists are capable of fulfilling higher thermal demands. In this context, long-term storage tests as well as temperature cycling tests were conducted. Moreover, the effect of various Cu pre-treatment methods on the adhesion of the solder masks was examined following 150, 175 and 200°C ageing processes. For this purpose, test panels were conditioned for 2000 hours at the respective temperatures and were submitted to a cross-cut test every 500 h. Within this test set-up, it was found that a multi-level chemical pre-treatment gives significantly better adhesion results, in particular at 175°C and 200°C, compared with a pre-treatment by brush or pumice brush. Also, breakdown voltage as well as tracking resistance were investigated. For an application in LED technology, the light reflectivity and white colour stability of the printed circuit board are of major importance, especially when high-power LEDs are used which can generate larger amounts of heat. For this reason, a very high coverage power and an intense white colour with high reflectivity values are essential for white solder masks. These "ultra-white" and largely non-yellowing LPiSM need to be able to withstand specific thermal loads, especially in combination with high-power LED lighting applications. The topic of thermal performance of coatings for electronics will also be discussed in view of printed heatsink paste (HSP) and thermal interface paste (TIP) coatings which are used for a growing number of applications. They are processed at the printed circuit board manufacturing level for thermal-coupling and heat-spreading purposes in various thermal management-sensitive fields, especially in the automotive and LED lighting industries. Besides giving an overview of the principle functionality, it will be discussed what makes these ceramic-filled epoxy- or silicone-based materials special compared to using "thermal greases" and "thermal pads" for heat dissipation purposes....

Publisher: Lackwerke Peters GmbH + Co KG

Lackwerke Peters GmbH + Co KG

Lackwerke Peters has progressively evolved into one of, if not the market leader for coating materials for assembled pcbs / flat packs in Europe, which includes renowned companies from aviation and aerospace technolog

Kempen, Germany

Manufacturer

Non-Destructive Test Methods

Sep 23, 2019 | ACI Technologies, Inc.

Failure analysis (FA), by its very nature, is needed only when things goawry. Before any testing is performed on the sample, a decision mustbe made as to whether or not the sample is allowed to be destroyedin the process of testing. Non-destructive testing can allow for re-use of the assembly since the functionality is not altered, but there still remains the possibility that inadvertent damage can occur through the course of the analysis. If non-destructive testing is preferred, then the following types of analysis can be performed. The testing can be divided into four categories: visual, X-ray (X-ray imaging and X-ray fluorescence), cleanliness (resistivity of solvent extract, ion chromatography, and Fourier transform infrared spectroscopy), and mechanical (non-destructive wire bond pull)....

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

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