KYZEN Corporation

QUANTIFYING THE IMPROVEMENTS IN THE SOLDER PASTE PRINTING PROCESS FROM STENCIL NANOCOATINGS AND ENGINEERED UNDER WIPE SOLVENTS

May 22, 2023 | Chrys Shea, Mike Bixenman, T.C. Loy, Debbie Carboni, Brook Sandy-Smith, Greg Wade, Ray Whittier, Joe Perault, Eric Hanson

Over the past several years, much research has been performed and published on the benefits of stencil nano-coatings and solvent under wipes. The process improvements are evident and well-documented in terms of higher print and end-of-line yields, in improved print volume repeatability, in extended under wipe intervals, and in photographs of the stencil's PCB-seating surface under both white and UV light. But quantifying the benefits using automated Solder Paste Inspection (SPI) methods has been elusive at best. SPI results using these process enhancements typically reveal slightly lower paste transfer efficiencies and less variation in print volumes to indicate crisper print definition. However, the improvements in volume data do not fully account for the overall improvements noted elsewhere in both research and in production....

The Relationship Between Cleanliness and Reliability/Durability

Apr 17, 2023 | Debbie Carboni

Outline/Agenda * Introduction of Ionics and ROSE * Evolution in technology * Rev H in the IPC-J-STD-001 * Real World Case Study * Conclusions...

Stencil Cleaning - A Practical Approach To Improving Yields And Maximizing Your Throughput

Nov 10, 2021 | Debbie Carboni

Main Points * Technologies for the job * More than a flat piece of Stainless * Compatibility * Solubility in stencil cleaning * Influencing factors * Best Practices to reduce misprints and increase yields...

WHY CLEAN A NO-CLEAN FLUX

Nov 04, 2020 | Mike Bixenman, DBA [Kyzen Corporation] Mark McMeen, [STI Corporation] Bruno Tolla, Ph.D. [Kester Corporation]

Residues present on circuit boards can cause leakage currents if not controlled and monitored. How "Clean is Clean" is neither easy nor cheap to determine. Most OEMs use analytical methods to assess the risk of harmful residues. The levels that can be associated with clean or dirty are typically determined based on the exposed environment where the part will be deployed. What is acceptably clean for one segment of the industry may be unacceptable for more demanding segments. As circuit assemblies increase in density, understanding cleanliness data becomes more challenging. The risk of premature failure or improper function is typically site specific. The problem is that most do not know how to measure or define cleanliness nor can they recognize process problems related to residues. A new site specific method has been designed to run performance qualifications on boards built with specific soldering materials, reflow settings and cleaning methods. High impedance measurements are performed on break off coupons designed with components geometries used to build the assembly. The test method provides a gauge of potential contamination sources coming from the assembly process that can contribute to electrochemical migration....

Cleaning Flux Residue under Leadless Components using Objective Evidence to Determine Cleaning Performance

Aug 14, 2019 | Mike Bixenman - KYZEN Corporation, Vladimir Sitko, Pavel Hub - PBT Works

Cleanliness is a product of design, including component density, standoff height and the cleaning equipment’s ability to deliver the cleaning agent to the source of residue. The presence of manufacturing process soil, such as flux residue, incompletely activated flux, incompletely cured solder masks, debris from handling and processing fixtures, and incomplete removal of cleaning fluids can hinder the functional lifetime of the product. Contaminates trapped under a component are more problematic to failure. Advanced test methods are needed to obtain "objective evidence" for removing flux residues under leadless components.</p><p>Cleaning process performance is a function of cleaning capacity and defined cleanliness. Cleaning performance can be influenced by the PCB design, cleaning material, cleaning machine, reflow conditions and a wide range of process parameters.</p><p>This research project is designed to study visual flux residues trapped under the bottom termination of leadless components. This paper will research a non-destructive visual method that can be used to study the cleanability of solder pastes, cleaning material effectiveness for the soil, cleaning machine effectiveness and process parameters needed to render a clean part....

Electrochemical Methods to Measure the Corrosion Potential of Flux Residues

Jul 27, 2017 | Mike Bixenman, DBA, David Lober, Anna Ailworth - Kyzen Corporation, Bruno Tolla, Ph.D., Jennifer Allen, Denis Jean, Kyle Loomis - Kester Corporation

Reliability Expectations of Highly Dense Electronic Assemblies is commonly validated using Ion Chromatography and Surface Insulation Resistance. Surface Insulation Resistance tests resistance drops on both cleaned and non-cleaned circuit assemblies. It is well documented in the literature that SIR detects ionic residue and the potential of this residue to cause leakage currents in the presence of humidity and bias. Residues under leadless components are hard to inspect for and to ensure flux residue is totally removed. The question many assemblers consider is the risk of residues that may still be present under the body of components....

Duo-Solvent Cleaning Process Development for Removing Flux Residue from Class 3 Hardware

Jul 28, 2016 | Mike Bixenman, DBA - Kyzen Corporation | Ryan Hulse, PHD - Honeywell International | Joe McChesney - CSD Automation

Packaging trends enable disruptive technologies. The miniaturization of components reduces the distance between conductive paths. Cleanliness of electronic hardware based on the service exposure of electrical equipment and controls can improve the reliability and cost effectiveness of the entire system. Problems resulting from leakage currents and electrochemical migration lead to unintended power disruption and intermittent performance problems due to corrosion issues.

Solvent cleaning has a long history of use for cleaning electronic hardware. Limitations with solvent based cleaning agents due to environmental effects and the ability to clean new flux designs commonly used to join miniaturized components has limited the use of solvent cleaning processes for cleaning electronic hardware. To address these limitations, new solvent cleaning agents and processes have been designed to clean highly dense electronic hardware.

The research study will evaluate the cleaning and electrical performance using the IPC B-52 Test Vehicle. Lead Free noclean solder paste will be used to join the components to the test vehicle. Ion Chromatography and SIR values will be reported....

Combination of Spray and Soak Improves Cleaning under Bottom Terminations

Oct 23, 2014 | Dr. Mike Bixenman; Kyzen Corporation, Julie Fields; Technical Devices Company, Eric Camden; Foresite.

The functional reliability of electronic circuits determines the overall reliability of the product in which the final products are used. Market forces including more functionality in smaller components, no-clean lead-free solder technologies, competitive forces and automated assembly create process challenges. Cleanliness under the bottom terminations must be maintained in harsh environments. Residues under components can attract moisture and lead to leakage currents and the potential for electrochemical migration (...)

The purpose of this research study is to evaluate innovative spray and soak methods for removing low residue flux residues and thoroughly rinsing under Bottom Termination and Leadless Components...

Stencil Printing Yield Improvements

Jun 05, 2014 | Dr. Mike Bixenman, Debbie Carboni, Jason Chan

Stencil printing capability is becoming more important as the range of component sizes assembled on a single board increases. Coupled with increased component density, solder paste sticking to the aperture sidewalls and bottom of the stencil can cause insufficient solder paste deposits and solder bridging. Yield improvement requires increased focus on stencil technology, printer capability, solder paste functionality and understencil cleaning.

(...) The purpose of this research is to study the wipe sequence, wipe frequency and wipe solvent(s) and how these factors interact to provide solder paste printing yield improvement....

Compatibility of Cleaning Agents With Nano-Coated Stencils

Mar 12, 2013 | David Lober and Mike Bixenman, D.B.A.

High density and miniaturized circuit assemblies challenge the solder paste printing process. The use of small components such as 0201, 01005 and μBGA devices require good paste release to prevent solder paste bridging and misalignment. When placing these miniaturized components, taller paste deposits are often required. To improve solder paste deposition, a nano-coating is applied to laser cut stencils to improve transfer efficiency. One concern is the compatibility of the nano-coating with cleaning agents used in understencil wipe and stencil cleaning. The purpose of this research is to test the chemical compatibility of common cleaning agents used in understencil wipe and stencil cleaning processes.Compatibility of Cleaning Agents With Nano-Coated Stencils...