Electronics Manufacturing Training

Technical Articles From BEST Inc.

Read technical articles about electronics manufacturing added by BEST Inc.

20 technical articles added by BEST Inc.

Company Information:

BEST offers professional rework, repair and prototype builds of PCBs. Our expertise is on BGA rework and QFN rework. Our experienced instructors teach professional soldering classes as we are an IPC certified training center

Rolling Meadows, Illinois, USA

Consultant / Service Provider, Manufacturer

  • Phone 847-797-9250
  • Fax 847-797-3255

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(1) SMT parts, accessories & PCB supplies item

(74) products in the catalog

(20) technical library articles

(35) news releases

Hand Printing using Nanocoated and other High End Stencil Materials

May 29, 2019 | Bob Wettermann

There are times when a PCB prototype needs to be built quickly to test out a design. In such cases where it is known early on that there will be multiple iterations or that a "one and done" assembly will be made that there will be some SMT assemblers who choose to hand print solder paste onto the board using a "frameless" stencil. In such cases where hand printing is used, the consistency of the printing technique has typically been in question. Furthermore, the effectiveness of both the nanocoatings as well as the higher end stainless steel materials, which have been heretofore studied in controlled printing environments, will be evaluated for their impact on the hand printing process.</p><p>The purpose of the study was to determine the effectiveness of select nanocoating materials as well as certain high end stainless steel stencil materials as they relate to the manual SMT printing process. A variety of nanocoatings were applied to SMT metal stencils and solder paste volume measurements were taken to compare the effectiveness....

Solder Paste for BGA Rework | Multiple Methods for Applying Paste Flux

Mar 30, 2017 | Bob Wettermann, BEST Inc. MIT

There are multiple methods, each with its associated benefits for given applications, for printing either solder paste or paste flux for BGA rework. Each of these methods is best-suited for a given situation, board layout and skill level of operators performing the BGA rework. This discussion will layout the various methods and present the specific circumstances for which the specific technique is most wellsuited. In addition, the pluses and minuses for each of the approaches will be discussed in detail....

BGA Rework Process

Feb 01, 2017 | Bob Wettermann

BGA Rework Course encompasses the skills necessary to perform rework of electronic printed circuit boards to include PBGA and CBGA technologies. There should be 'one-stop' solution, that offers a wide range of ball grid array rework and repair services....

PCB Laser Depanelizing Using a UV Laser

Oct 06, 2016 | Bob Wettermann

One of the methods gaining in popularity for singulating rigid/flex, rigid and flex circuit boards post assembly is through the use of laser routing. This method has the advantage of speed, positional accuracy, no tooling wear and lastly no induced mechanical stresses on components during the singulating process....

Adhesive Backed Plastic Stencils vs Mini Metal Stencils

Aug 27, 2015 | Bob Wettermann, MIT

Ever since there has been a widespread usage of surface mount parts, the trend of continued shrinkage of devices with ever finer pitches has continued to challenge PCB assemblers for the rework of same. Todays' pitches are commonly 0.5 to 0.4mm with packages of tiny outline sizes, 5 -10mm square, making the rework of such devices a challenge. In addition to the handling and inspection challenges comes the board density. Spacing to neighboring components continues to be compressed so the rework techniques should not damage neighboring components....

Plastic vs Metal Stencils for Prototype Printing

Sep 11, 2014 | Bob Wettermann.

This article goes through the pluses and minuses of using plastic stencils for DIY prototypes. The release efficiency is measured and "rules of thumb" for using one type vs another is explained....

Reliability of Reworked QFNs

Sep 11, 2014 | CRANE.

In this DOD study the reliability of reworked QFNs is studied with the outcome being that a stay in place stencil does not impact the reliability of a QFN reworked using this technique...

Reballing a QFN Simplifies QFN Rework

Sep 11, 2014 | Bob Wettermann.

There are a variety of methods one can use to rework QFNs. This paper explains one of the ways to get very little center ground voiding while making it easy to place a tiny component with almost no keep out areas....

Performance of Kapton Stencils vs Stainless Steel Stencils for Prototype Printing Volumes Processes

Jul 03, 2013 | Bob Wettermann, Hung Hoang

It has been demonstrated in numerous pieces of work that stencil printing, one of the most complex PCB assembly processes, is one of the largest contributors to defects (Revelino et el). This complexity extends to prototype builds where a small number of boards need to be assembled quickly and reliably. Stencil printing is becoming increasingly challenging as packages shrink in size, increase in lead count and require closer lead spacing (finer pitch). Prototype SMT assembly can be further divided between industrial and commercial work and the DIYer, hobbyist or researcher groups. This second group is highly price sensitive when it comes to the materials used for the board assembly as their funds are sourced from personal or research monies as opposed to company funds. This has led to development of a lower cost SMT printing stencil made from plastic film as opposed to the more traditional stainless steel stencil used by industrial and commercial users.This study compares the performance of these two traditional materials and their respective impact on solder paste printing including efficiency and print quality....

Component Shortages Causing Electronics Manufacturers to "Use All Means Necessary" to Ship Products

Nov 24, 2010 | Bob Wettermann

As the electronics manufacturing and assembly industry in the US recovers to some degree from the economic crisis which began in 2008, the challenge of component shortages has risen to the top as one of the stumbling blocks for contract assemblers and cap...

A New Stenciling Method for Reworking SMT Components

Jul 15, 2010 | Bob Wettermann

When reworking more complex SMT components such as finer pitch SMT components, SMTconnectors and even area array devices, the most common method of printing on the printing selectively on the PCB has some serious shortcomings. The most significant problem...

Reworking QFN's Newly Developed Cost Effective Approach

Feb 18, 2010 | Best Inc

This paper describes a new rework process for leadless devices where the devices can be manually placed without relying on capital equipment....

Micro-Sectioning of PCBs for Failure Analysis

Jan 13, 2010 | Bob Wettermann

Micro-sectioning (sometimes referred to as cross-sectioning)is a technique, used to characterize materials or to perform a failure mode analysis, for exposing an internal section of a PCB or package. Destructive in nature, cross-sectioning requires encapsulation of the specimen in order to provide support, stability, and protection. Failures that can be investigated through micro-sectional analysis include component defects, thermo-mechanical failures, processing failures related to solder reflow, opens or shorts, voiding and raw material evaluations....

Lead-Free BGA Rework-Transition Issues

Aug 16, 2007 | Best Inc

While experienced inspectors may be able to determine the aesthetic differences between a lead-free PCB assembly and a tin-lead version, one cannot rely on the "experienced eye". "Less wetting out to the pad edges" (Figure A) and "graininess and lack of shininess of the solder joint" (Figure B) are typical comments about some lead-free solder joints. However, in cases where a Nitrogen atmosphere was present during the reflow of the solder joint (Figure C), there will be little visual differences between the lead free alloys and their tin-lead counterparts....

Selective Solder Paste Deposition Reliability Test Results.

Jun 21, 2007 | Bob Wettermann.

The rapid assimilation of Ball Grid Array (BGA) and other Area Array Package technology in the electronics industry is due to the fact that this package type allows for a greater I/O count in a smaller area while maintaining a pitch that allows for ease of manufacture (...) While there have been several studies comparing these two attachment methods, this study highlights the effect of rework technique on the electrical characteristics and reliability of reworked BGAs....

New BGA Solder Mask Repair Technique Using Laser Cut Stencils

Feb 01, 2007 | Ronald D. Schaeffer, Chief Executive Officer, Photomachining.

The increased replacement of high lead count SMT devices with BGAs and other high ball count area array packages has brought increased challenges to PCB rework and repair. Often solder mask areas surrounding BGA pad areas are damaged when components are removed....

BGA Rework. A Comparative Study of Selective Solder Paste Deposition For Area Array Packages

Feb 01, 2007 | Ray Cirimele, Best, Inc

The rapid assimilation of Ball Grid Array (BGA) and other Area Array Package technology in the electronics industry is due to the fact that this package type allows for a greater I/O count in a smaller area while maintaining a pitch that allows for ease of manufacture....

Surface Insulation Resistance (SIR) Testing

Feb 01, 2007 | Roy Johnson, Senior Staff Engineer AG Communication Systems.

Purpose: Compare the Surface Insulation Resistance of reworked BGA Test samples made with standard solder balls using a flux only reattachment and samples made including the StencilQuik™ product from Best Inc. with solder balls using a flux only reattachment....

BGA Thermal Shock Testing

Feb 01, 2007 | Roy Johnson Senior Staff Engineer AG Communication Systems.

The purpose of the testing was to compare the resistance and check for open circuit conditions of reworked BGA test samples made with and without StencilQuik™ after 500 thermal shock cycles. StencilQuick™ is a product of Best Inc. In this series of tests, the resistance of daisy chain resistance patterns running between the BGA and test board after exposure to thermal shock was measured....

StencilQuick™ Lead-Free Solder Paste Rework Study

Jan 31, 2007 | Ray Cirimele, BEST Inc

The goal of this project is to evaluate the reliability of lead-free BGA solder joints with a variety of different pad sizes using several different BGA rework methods. These methods included BGAs reworked with both flux only and solder paste attachment techniques and with or without the use of the BEST stay in place StencilQuick™. The daisy chained test boards were placed into a thermal test chamber and cycled between -25ºC to 125ºC over a 30 minute cycle with a 30 minute dwell on each end of the cycle. Each BGA on the board was wired and the continuity assessed during the 1000 cycles the test samples were in the chamber. ...

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