SMT, PCB, EMS Technical Articles

Effect Of Vacuum Reflow On Solder Joint Voiding In Bumped Components

Oct 31, 2022 | Arvind Srinivasan Karthikeyan, Sa'd Hamasha, Michael Meilunas, and Fred Dimock

Voids affect the thermal characteristics and mechanical properties of a solder joint, thereby affecting the reliability of the solder interconnect. The automotive sector in particular is requiring the mitigation of solder voids in various electronic control modules to the minimum possible level. Earlier research efforts performed to decrease voids involved varying the reflow profile, paste deposit, paste alloy composition, stencil aperture, and thickness. Due to the various advantages they offer, the use of Ball Grid Array packages is common across all industry sectors. They are also prone to process voiding issues. This study was performed to determine if vacuum assisted reflow process can help alleviate the voids in area array solder joints. Test parameters in this study largely focused on vacuum pressure level and vacuum dwell time....

Publisher: Auburn University

Auburn University

Auburn University is a comprehensive land-grant institution with primary missions including instruction, research, and extension/outreach.

Auburn, Alabama, USA

Research Institute / Laboratory / School

Lead-Free and Mixed Assembly Solder Joint Reliability Trends

Oct 31, 2022 | Jean-Paul Clech, Ph.D.

This paper presents a quantitative analysis of solder joint reliability data for lead-free Sn-Ag-Cu (SAC) and mixed assembly (SnPb + SAC) circuit boards based on an extensive, but non-exhaustive, collection of thermal cycling test results. The assembled database covers life test results under multiple test conditions and for a variety of components: conventional SMT (LCCCs, resistors), Ball Grid Arrays, Chip Scale Packages (CSPs), wafer-level CSPs, and flip-chip assemblies with and without underfill. First-order life correlations are developed for SAC assemblies under thermal cycling conditions. The results of this analysis are put in perspective with the correlation of life test results for SnPb control assemblies. Fatigue life correlations show different slopes for SAC versus SnPb assemblies, suggesting opposite reliability trends under low or high stress conditions. The paper also presents an analysis of the effect of Pb contamination and board finish on lead-free solder joint reliability. Last, test data are presented to compare the life of mixed solder assemblies to that of standard SnPb assemblies for a wide variety of area-array components. The trend analysis compares the life of area-array assemblies with: 1) SAC balls and SAC or SnPb paste; 2) SnPb balls assembled with SAC or SnPb paste....

Publisher: EPSI Inc.

EPSI Inc.

We work on the physical design, reliability and failure analysis of electronic components, solder joints and PCB assemblies. We provide expertise in the assessment of both standard SnPb and Pb-free solder joint reliability.

Montclair, New Jersey, USA

Consultant / Service Provider

Surfaces of mixed formulation solder alloys at melting

Oct 31, 2022 | M. J. Bozack, J. C. Suhling, Y. Zhang, Z. Cai, and P. Lall

Mixed formulation solder alloys refer to specific combinations of Sn-37Pb and SAC305 (96.5Sn–3.0Ag–0.5Cu). They present a solution for the interim period before Pb-free electronic assemblies are universally accepted. In this work, the surfaces of mixed formulation solder alloys have been studied by in situ and real-time Auger electron spectroscopy as a function of temperature as the alloys are raised above the melting point. With increasing temperature, there is a growing fraction of low-level, bulk contaminants that segregate to the alloy surfaces. In particular, the amount of surface C is nearly _50–60 at. % C at the melting point. The segregating impurities inhibit solderability by providing a blocking layer to reaction between the alloy and substrate. A similar phenomenon has been observed over a wide range of (SAC and non-SAC) alloys synthesized by a variety of techniques. That solder alloy surfaces at melting have a radically different composition from the bulk uncovers a key variable that helps to explain the wide variability in contact angles reported in previous studies of wetting and adhesion. VC 2011 American Vacuum Society. [DOI: 10.1116/1.3584821]...

Publisher: Auburn University

Auburn University

Auburn University is a comprehensive land-grant institution with primary missions including instruction, research, and extension/outreach.

Auburn, Alabama, USA

Research Institute / Laboratory / School

Microstructure and Intermetallic Formation in SnAgCu BGA Components Attached With SnPb Solder Under Isothermal Aging

Oct 31, 2022 | Anupam Choubey, Michael Osterman, and Michael Pecht

The global transition to lead-free (Pb-free) electronics has led component and equipment manufacturers to transform their tin–lead (SnPb) processes to Pb-free. At the same time, Pb-free legislation has granted exemptions for some products whose applications require high long-term reliability. However, due to a reduction in the availability of SnPb components, compatibility concerns can arise if Pb-free components have to be utilized in a SnPb assembly. This compatibility situation of attaching a Pb-free component in a SnPb assembly is generally termed "backward compatibility." This paper presents the results of microstructural analysis of mixed solder joints which are formed by attaching Pb-free solder balls (SnAgCu) of a ball-grid-array component using SnPb paste. The experiment evaluates the Pb phase coarsening in bulk solder microstructure and the study of intermetallic compounds formed at the interface between the solder and the copper pad....

Publisher: CALCE Center for Advanced Life Cycle Engineering

CALCE Center for Advanced Life Cycle Engineering

The largest electronic products research center focused on electronics reliability, is dedicated to providing a knowledge and resource base to support the development of competitive electronic components, products and systems.

College Park, Maryland, USA

Consultant / Service Provider, Training Provider

00338005-01 SMT Spare Parts Snap Switch Changer S 826B For Siemens Pick And Place Machine

Oct 31, 2022 | Germany

Model: IENENS PL EA Servo Motor Usage: Siemens Pick And Place Machine Description: Drive Module SERVO Wight: 2kg Packing: Paper Case Product Description: Motor High Light: 00338005-01 SMT Spare Parts, Snap Switch Changer SMT Spare Parts, SIEMENS Spare Parts Snap Switch Changer...

Publisher: Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Our company was established in 2013, specializing in providing SMT accessories. We are a fully electronic contract wholesaler, providing complete services, including BOM, material procurement, quality assurance,

Baoan District, Shenzhen, Guangdong, China, China

Consultant / Service Provider

0032254403 A700 Vacuum Nozzle Type 418 SIEMENS AG Pip 418 Komplett Vectra

Oct 31, 2022 | Germany

Minimum Order Quantity: 1/pcs Price: Negotiable,EXW Price Packaging Details: High quality carton packaging Delivery Time: 1-2 work days Payment Terms: L/C, D/A, D/P, T/T, Western Union, MoneyGram Supply Ability: 1000pcs monthly, delivery time 1-2 days...

Publisher: Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Our company was established in 2013, specializing in providing SMT accessories. We are a fully electronic contract wholesaler, providing complete services, including BOM, material procurement, quality assurance,

Baoan District, Shenzhen, Guangdong, China, China

Consultant / Service Provider

00341941S01 SMT Spare Parts Oben Stripping Device Plate 12*16mm Feeder

Oct 31, 2022 | Germany

Model: STRIPPING DEVICE PLATE Type: High-speed Chip Mounter Brand: SIEMENS SIPLACE ASM QUALITY: 100% Tested Usage: SIPLACE SMT Placement Machine HIGH LIGHT: Surface Mount Components, Smt Machine Part High Light: 00341941S01 SMT Spare Parts, 12*16mm SMT Spare Parts, 00341941S01...

Publisher: Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Our company was established in 2013, specializing in providing SMT accessories. We are a fully electronic contract wholesaler, providing complete services, including BOM, material procurement, quality assurance,

Baoan District, Shenzhen, Guangdong, China, China

Consultant / Service Provider

00343010-01 SMT Spare Parts SIEMENS PL EA MCH Filter G1/2 Modulair 112

Oct 31, 2022 | Germany

Type: Filter Cup Model: Siemens Placement Machine Certification: CE，ROHS Trademark: Siemens Brief Description: Feeder Fixing Screws Wight: 1kg High Light: 00343010-01 SMT Spare Parts, ROHS SMT Spare Parts, SIEMENS PL EA MCH Filter...

Publisher: Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Our company was established in 2013, specializing in providing SMT accessories. We are a fully electronic contract wholesaler, providing complete services, including BOM, material procurement, quality assurance,

Baoan District, Shenzhen, Guangdong, China, China

Consultant / Service Provider

00344065-03 KST-75-UP Siemens PCB Camera ALLIED Vision Technologies GmbH M60S

Oct 31, 2022 | Germany

Product Name: ALLIED Vision Technologies GmbH M60S Processing Customization: No Quality: 100% Tested Automatic Manual: Automatic Brand: Siemens AG Custom Processing: Yes High Light: 00344065-03, 00344065-03 Siemens PCB Camera, KST-75-UP Siemens PCB Camera...

Publisher: Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Our company was established in 2013, specializing in providing SMT accessories. We are a fully electronic contract wholesaler, providing complete services, including BOM, material procurement, quality assurance,

Baoan District, Shenzhen, Guangdong, China, China

Consultant / Service Provider

00344065-03 KST-75-UP Siemens PCB Camera ALLIED Vision Technologies GmbH M60S

Oct 31, 2022 | Germany

Product Name: ALLIED Vision Technologies GmbH M60S Processing Customization: No Quality: 100% Tested Automatic Manual: Automatic Brand: Siemens AG Custom Processing: Yes High Light: 00344065-03, 00344065-03 Siemens PCB Camera, KST-75-UP Siemens PCB Camera...

Publisher: Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Shenzhen Zhongrun Hi-Tech Technology Co., Ltd.

Our company was established in 2013, specializing in providing SMT accessories. We are a fully electronic contract wholesaler, providing complete services, including BOM, material procurement, quality assurance,

Baoan District, Shenzhen, Guangdong, China, China

Consultant / Service Provider