A leading global supplier of assembly materials to the electronic assembly, component and microelectronic marketplaces.

Manufacturer of Assembly Material, Soldering

Kester is a leading global supplier of assembly materials to the electronic assembly, component and microelectronic marketplaces. Our products include an array of basic and high-tech attachment materials including traditional soldering chemicals, bar and wire solder and paste products. We serve a worldwide customer base with facilities in North America, Europe and Asia. We are an Illinois Tool Works (ITW) Company. ITW is one of the world’s leading diversified manufacturers of specialized industrial equipment, consumables, and related service businesses with more than 100 years of history and over 800 decentralized business units in nearly 60 countries. Kester offers the following solutions:

  • Solder Paste
  • Liquid Solder Flux
  • Solder Wire
  • Bar Solder
  • Tacky Solder Flux (TSF)
  • Preforms
  • SE-CURE™ advanced materials
  • A full spectrum of global customer technical support

Kester Postings

5 products »

Liquid Solder Flux

Lead-free wave and selective soldering systems require exposing the flux to slightly higher soldering temperatures. Lead-free alloys traditionally wet metal surfaces more slowly than tin-lead. Kester liquid fluxes for lead-free assembly have new a...

Solder Materials

Liquid Solder Flux

Solder Paste

Kester offers a complete line of solder paste to fit the needs of the electronic assembly market. The preferred products below cover the complete range of application types including No-Clean, Water Soluble, Halogen-Free and Lead-Free. ...

Solder Materials

Solder Paste

Solder Wire

Kester wire products have been developed to provide superior performance for hand soldering in the electronics industry. While the globally available preferred products are listed below, other combinations and core fluxes may be available. The Kes...

Solder Materials

Solder Wire

Tacky Solder Fluxes

Kester Tacky Solder Fluxes (TSFs) are the industrial standard for Flip Chip and BGA Sphere Attach. With viscosities optimized for high speed application and holding of a chip or sphere in place prior to reflow, Kester TSF’s enable wide process ...

Solder Materials

Tacky Solder Fluxes

Bar Solder

Manufactured by a special process that controls the inclusions of oxides and metallic and non-metallic impurities, Kester Ultrapure® is the industry standard bar solder for use in high tech electronic applications where lower surface tension and ...

Solder Materials

Bar Solder

15 technical articles »

Reactivity Of No-Clean Flux Residues Trapped Under Bottom Terminated Components

Jul 20, 2017 | Bruno Tolla, Ph.D., Jennifer Allen, Kyle Loomis - Kester Corporation, Mike Bixenman, DBA - KYZEN Corporation

As electronic devices increase functionality in smaller form factors, there will be limitations, obstacles and challenges to overcome. Advances in component technology can create issues that may have time delayed effects. One such effect is device failure due to soldering residues trapped under bottom terminated components. If the residues trapped under the component termination are active and can be mobilized with moisture, there is the potential for ion mobilization causing current leakage....

How to Use the Right Flux for the Selective Soldering Application

May 17, 2017 | Bruno Tolla Ph.D, Denis Jean, Xiang Wei Ph.D

The selective soldering application requires a combination of performance attributes that traditional liquid fluxes designed for wave soldering applications cannot fulfill. First, the flux deposition on the board needs to be carefully controlled. Proper fine tuning of the flux physicochemical characteristics combined with a process optimization are mandatory to strike the right balance between solderability and reliability. However, localization of the flux residue through the drop jet process is not enough to guarantee the expected performance level. The flux needs to be designed to minimize the impact of unavoidable spreading and splashing events.

From this perspective a fundamental understanding of the relationships between formulation and reliability is critical. In this application, thermal history of the flux residues (from room temperature to solder liquidus) is a key performance driver. Finally, it is necessary to conduct statistically designed experiments on industrial selective soldering machines in order to map the relationships between flux characteristics and selective process friendliness....

Partially-Activated Flux Residue Impacts on Electronic Assembly Reliabilities

Dec 29, 2016 | Yanrong Shi, Ph.D., Kyle Loomis, Jennifer Allen, Bruno Tolla, Ph.D.

The reliabilities of the flux residue of electronic assemblies and semiconductor packages are attracting more and more attention with the adoption of no-clean fluxes by majority of the industry. In recent years, the concern of "partially activated" flux residue and their influence on reliability have been significantly raised due to the miniaturization along with high density design trend, selective soldering process adoption, and the expanded use of pallets in wave soldering process. When flux residue becomes trapped under low stand-off devices, pallets or unsoldered areas (e.g. selective process), it may contain unevaporated solvent, "live" activators and metal complex intermediates with different chemical composition and concentration levels depending on the thermal profiles. These partially-activated residues can directly impact the corrosion, surface insulation and electrochemical migration of the final assembly.

In this study, a few application tests were developed internally to understand this issue. Two traditional liquid flux and two newly developed fluxes were selected to build up the basic models. The preliminary results also provide a scientific approach to design highly reliable products with the goal to minimize the reliability risk for the complex PCB designs and assembly processes.

This paper was originally published by SMTA in the Proceedings of SMTA International


Lead-free SMT Soldering Defects How to Prevent Them

Oct 23, 2012 | Peter Biocca, Senior Development Engineer

Tin-Silver-Copper alloys are the primary choice for lead-free SMT assembly. Although there are other options available such as alloys containing bismuth or indium and other elements, tin-silver-copper solders, also known as SAC alloys are by far the most popular. They are used by approximately 65% of users, as last surveyed by Soldertec in 2003....

SnCu Based Alloy Design for Lower Copper Dissolution and Better Process Control

Feb 13, 2009 | Peter Biocca, Senior Engineer, Technical Manager; Kester ITW,

To meet the market demand for a best-in-class, low-cost leadfree alloy for wave, selective and dip soldering...

Creating Solder Joint Reliability with SnCu Based Solders Some Practical Experiences

Jan 15, 2009 | Peter Biocca, Senior Market Development Engineer, Kester.

Tin-silver-copper has received much publicity in recent years as the lead-free solder of choice. SAC305 was endorsed by the IPC Solder Value Product Council in the United States as the preferred option for SMT assembly; most assemblers have transitioned to this alloy for their solder paste requirements. The SAC305 alloy due to its 3.0% content of silver is expensive when compared to traditional 63/37 for this reason many wave assemblers are opting for less costly options such as tin-copper based solders for their wave, selective and dip tinning operations....

Lead-Free Reliability - Building It Right The First Time

Jul 01, 2008 | Peter Biocca

As lead-free and RoHS compliancy fast approaches, it is more important than ever to build it right the first time. Lead-free assembly and RoHS will bring about numerous changes and the number of variables with which to contend is increasing, creating increased risk of defects and reduced product reliability. However, understanding what the variables are and their impact on the assembly can great increase product reliability....

Developing a Reliable Lead-free SMT Process

Jan 03, 2008 | Peter Biocca, Senior Development Engineer, Kester.

Lead-free SMT can be achieved reliably if several process requirements are implemented carefully. Some of the variables to account for are listed below. The most common alloys used in lead-free SMT are tin-silver-copper alloys; these alloys all have a meting range between 217- 220°C. These alloys all melt at higher temperatures than traditional leaded solders such as the 63/37which has a melting point of 183 °C....

Case Study on the Validation of SAC305 and SnCu Based Solders in SMT, Wave and Hand-soldering at the Contract Assembler Level

Nov 15, 2007 | Peter Biocca, Carlos Rivas

At the contractor level once a product is required to be soldered with lead-free solders all the processes must be assessed as to insure the same quality a customer has been accustomed to with a Sn63Pb37 process is achieved. The reflow, wave soldering and hand assembly processes must all be optimized carefully to insure good joint formation as per the appropriate class of electronics with new solder alloys and often new fluxes....

Manufacturing Considerations When Implementing Voc-Free Flux Technology

May 07, 1999 | David Scheiner, Senior Technical Service Engineer Kester

In 1990 the United States Environmental Protection Agency Issued the Clean Air Act. The Clean Air Act and subsequent amendments are designed to limit the use of chemicals that contain volatile organic compounds (VOCs). The document goes into great detail setting limits for allowable VOC emissions for different industries....

5 more technical articles from Kester »

47 news releases »

Kester to Exhibit & Present at SMTA China East/NEPCON China

Apr 10, 2017 | Kester will be exhibiting (booth #1H43) at SMTA China East/NEPCON, which will take place April 25-27 at the Shanghai World Expo Exhibition & Convention Center. Kester’s booth will offer attendees the opportunity to meet with the sales team and learn more about Kester’s new products.

Kester to Exhibit at SMT Hybrid Packaging 2017

Apr 04, 2017 | Kester will be exhibiting (booth # 4-533), at SMT Hybrid Packaging 2017, which will take place May 16-18 at the Exhibition Centre in Nuremberg, Germany.

Kester to Present at SNEC 11th (2017) International Photovoltaic Power Generation Conference & Exhibition

Mar 31, 2017 | Kester’s Dr. Yanrong Shi will present “Insights of solder flux fundamentals in solar module assembly” on Thursday, April 20 at 3:00pm at SNEC 11th (2017) International Photovoltaic Power Generation Conference & Exhibition. SNEC will take place April 18-20, 2017 in Shanghai.

Kester Launches WP601-ZH Solder Paste

Mar 13, 2017 | Kester is proud to announce the launch of WP601-ZH, a zero-halogen, lead-free, water-soluble solder paste formula for both nitrogen and air reflow applications. WP601-ZH is a breakthrough in water-soluble solder paste technology, providing a combination of consistent print performance at wide humidity levels, excellent solderability and ease of cleaning, while maintaining a zero-halogen flux formulation.

Kester To Present at the SMTA South East Asia Technical Conference on Electronics Assembly

Mar 10, 2017 | On Wednesday, March 29 Kester’s Bruno Tolla and Kyzen’s Mike Bixenman will present “Development of a Risk Profile from Flux Residues Trapped under Leadless Components” at the SMTA South East Asia Technical Conference on Electronics Assembly.

Kester to Participate in SMTA Panel Discussion

Mar 08, 2017 | On Wednesday, March 15 Kester’s Senior Field Applications Support Engineer, Mike Kaminsky, will be part of the SMTA Space Coast Chapter Panel Discussion on "Avoiding the Voids in Reflow Soldering".

Kester To Exhibit at Upcoming SMTA Texas Expos

Mar 02, 2017 | Kester will be exhibiting at SMTA Dallas Expo & Forum (booth #416) on Tuesday, March 7 at the Plano Centre in Plano, TX. On Thursday, March 9 Kester will exhibit again at the SMTA Houston Expo & Tech Forum (booth #64) which will take place at the Stafford Centre in Stafford, TX.

Kester To Exhibit at Upcoming SMTA Texas Expos

Mar 02, 2017 | Kester will be exhibiting at SMTA Dallas Expo & Forum (booth #416) on Tuesday, March 7 at the Plano Centre in Plano, TX. On Thursday, March 9 Kester will exhibit again at the SMTA Houston Expo & Tech Forum (booth #64) which will take place at the Stafford Centre in Stafford, TX.

Kester Wins Circuit Assembly’s 2017 NPI Award

Feb 28, 2017 | Kester was awarded Circuit Assembly’s 2017 New Product Introduction (NPI) Award in the category of Flux for SELECT-10™ Selective Solder Flux. The award was presented during the IPC APEX EXPO 2017.

Kester to Host Technical Rework Seminar

Feb 21, 2017 | Kester is hosting a Technical Rework Seminar, scheduled to take place Tuesday, March 7 at Kester’s Global Headquarters in Itasca, IL.

37 more news releases from Kester »

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