-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueBox Build
One trend is to add box build and final assembly to your product offering. In this issue, we explore the opportunities and risks of adding system assembly to your service portfolio.
IPC APEX EXPO 2024 Pre-show
This month’s issue devotes its pages to a comprehensive preview of the IPC APEX EXPO 2024 event. Whether your role is technical or business, if you're new-to-the-industry or seasoned veteran, you'll find value throughout this program.
Boost Your Sales
Every part of your business can be evaluated as a process, including your sales funnel. Optimizing your selling process requires a coordinated effort between marketing and sales. In this issue, industry experts in marketing and sales offer their best advice on how to boost your sales efforts.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
Low-Temperature Thick Film Pastes Permit Lead-Free Soldering
December 8, 2015 | Steven Grabey, Heraeus ElectronicsEstimated reading time: 2 minutes
New technologies in the printed electronics industry have fostered an increased interest in low-temperature polymer thick film products. Industry expectations are demanding that low-temperature products perform at the same level as their high-temperature counterparts, including high reliability, strong adhesion, and solderability with lead-free solders.
Much of the shift to lead-free solders is due to environmental concerns and legislation that has surfaced over the past 15 years. Traditionally, it has only been possible to use leaded solders for soldering to polymer-based thick film conductors. While using lead-free solders is beneficial both to the industry and the environment, they pose challenges during processing. The high temperatures required for lead-free soldering generate a harsh environment that is too severe for polymer thick film pastes to survive.
Using New Substrates
As the electronic industry moves towards flexible electronics, they are realizing the benefits in using substrates such as treated glass and aluminum that require a low-temperature-processing, polymer thick film. These materials not only offer a cost-effective approach to building complex, integrated circuits, they also provide a viable option to manufacturers dealing with the new demands of substrates that cannot handle temperatures higher than 500°C.
Polymer thick film materials have the versatility to be engineered depending on substrate and preferred application method such as screen printing, stencil printing, dispensing, dipping, and roll-to-roll printing. For traditional thick film materials, additive processing has always offered benefits including ease of use, simple design changes, and the ability to manufacture patterns from simple circuits to intricate designs.
The addition of polymer thick film to this category not only continues to have these listed advantages but also brings new gains such as: low temperature processing, quick-curing steps, and the ability to offer many of the same benefits as high-temperature thick film material without the need for the traditional firing step.
Despite the known advantages for polymer thick film materials, they are not as widely accepted in the industry as equivalent alternatives to their standard high-temperature thick film counterparts. This is due to two disadvantages – reliability and process-ability – prevalent in polymer thick films. Although many polymer thick films are considered to be reliable, they do not have the typical life span of a cermet (ceramic-metal) paste.
It is difficult to use lead-free solders when working with polymer materials. Frequently, the processing temperatures of the solders are greater than those of the polymers used to create the conductive pastes. This leads to the leaching of the conductive materials and the poor wetting of the solder.
To solve these problems, a new polymer thick film paste has been developed that is compatible with a variety of substrates and readily accepts lead-free solder. This easy-to-process paste features low temperature curing (150°C – 200°C); offers excellent solderability with SAC305 solder; and is RoHS- and REACH compliant. It allows conductive polymer pastes to be used in a variety of functions such as position sensors, low-temperature heater applications, and tempered-glass connection points.
This article will present data that shows how the thick film paste was assessed under various parameters including solder acceptance, adhesion, and thermal and SEM analysis.
Editor's Note: This article originally appeared in the December 2015 issue of SMT Magazine.
Suggested Items
AIM Solder’s Dillon Zhu to Present on Ultraminiature Soldering at SMTA China East
04/22/2024 | AIMAIM Solder, a leading global manufacturer of solder assembly materials for the electronics industry, is pleased to announce that Dillon Zhu will present on the topic: Ultraminiature Soldering: Techniques, Technologies, and Standards at SMTA China East. This event is being held at the Shanghai World Expo Exhibition & Convention Center from April 24-25.
AIM to Highlight NC259FPA Ultrafine No Clean Solder Paste at SMTA Wisconsin Expo & Tech Forum
04/18/2024 | AIMAIM Solder, a leading global manufacturer of solder assembly materials for the electronics industry, is pleased to announce its participation in the upcoming SMTA Wisconsin Expo & Tech Forum taking place on May 7 at the Four Points by Sheraton | Milwaukee Airport, in Milwaukee, Wisconsin.
Hentec/RPS Publishes an Essential Guide to Selective Soldering Processing Tech Paper
04/17/2024 | Hentec Industries/RPS AutomationHentec Industries/RPS Automation, a leading manufacturer of selective soldering, lead tinning and solderability test equipment, announces that it has published a technical paper describing the critical process parameters that need to be optimized to ensure optimal results and guarantee the utmost in end-product quality.
Empowering Electronics Assembly: Introducing ALPHA Innolot MXE Alloy
04/16/2024 | MacDermid Alpha Electronics SolutionsIn the rapidly evolving electronics industry, where innovation drives progress, MacDermid Alpha Electronics Solutions is committed to setting a new standard. Today, we are pleased to introduce ALPHA Innolot MXE, a revolutionary alloy meticulously engineered to address the critical needs of enhanced reliability and performance in modern electronic assemblies.
New Book on Low-temperature Soldering Now Available
04/17/2024 | I-Connect007I-Connect007 is pleased to announce that The Printed Circuit Assembler’s Guide to… Low-temperature Soldering, Vol. 2, by subject matter experts at MacDermid Alpha Electronics Solutions, is now available for download.