This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
This Website Uses Cookies
By closing this message or continuing to use our site, you agree to our cookie policy. Learn More
This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
Adhesives Mag logo
search
cart
facebook twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
Adhesives Mag logo
  • News
    • Adhesives & Sealants Headlines
    • Mergers/Acquisitions
    • Events Calendar
    • Market Trends
    • Price Adjustments
  • New Products
  • Topics
    • Finished Adhesives and Sealants
    • Pressure-Sensitive Adhesives (PSAs)
    • Coatings
    • Raw Materials and Chemicals
    • Materials Handling/Processing
    • Meter/Mix/Dispense
    • Curing
    • Testing/Quality Control
    • Packaging of Adhesives & Sealants
    • Converting/Packaging
    • Composites
    • Sustainability
  • Columns
    • Ask Dr. Dave
    • Strategic Solutions
    • IP in Depth
    • Tape Talk
  • ASI Top 20
  • Multimedia
    • Videos
    • Podcasts
    • Photo Galleries
    • Webinars
    • Mobile App
  • Explore
    • Blog
    • ASI Store
    • Industry Links
    • Market Research
  • Magazine
    • Current Issue
    • Digital Edition
    • Advertiser Index
    • Classifieds & Services Marketplace
  • Directories
    • Buyers' Guide
    • Global Adhesives & Sealants Directory
    • Raw Materials, Chemicals, Polymers and Additives Handbook
    • Equipment Handbook
    • Distributor Directory
    • Take A Tour
  • eNewsletters
  • Advertise
    • Contact
    • Custom Content & Marketing Services
Home » Stencil Prinitng SMT Adhesives: A Technology Review

Stencil Prinitng SMT Adhesives: A Technology Review

September 1, 2004
Reprints
No Comments


Anyone closely involved with the process of surface-mount assembly is familiar with the challenges of materials deposition. This complex process requires highly developed materials and equipment to produce reliable results. In the past, SMT adhesive deposition was accomplished primarily by high-speed automatic dispensing, pin transfer and stencil printing.

Adhesive for SOIC
Each of these methods has its strengths and weaknesses, and, as the needs of the SMT assembly industry change, careful consideration must be made to determine the appropriate method for new applications. The industry of high-volume surface-mount assembly is very competitive, with product designs changing rapidly. To remain profitable, assembly houses must maintain a high-quality standard while maximizing throughput and flexibility. SMT placement equipment manufacturers are rising to the challenges of this fast-paced industry by producing machines capable of more than 70,000 placements per hour.

Dual dot deposit
As a result, the assembly business is shifting its focus from placement equipment to materials deposition equipment. At present, the most widely used method of adhesive deposition is high-speed automatic dispensing. This method is excellent for controlling individual deposition volumes and dispense locations. The limiting factor, however, is speed. Current high-end dispensers are only able to produce up to 40,000 "dots" per hour. This process can quickly become a bottleneck in a high-throughput assembly line.

Oblong deposits passive component
Pin transfer is a high-speed alternative to dispensing, but it has several limitations. Deposition locations are fixed in complex and expensive tooling plates that make changeovers slow. In addition, product design changes are expensive and difficult to accommodate.

Stencil printing, recognized for many years as a viable and cost-effective method of applying adhesives, is now emerging as the chosen deposition method for high-throughput assembly environments. Increasing component counts and faster placement equipment require a method of adhesive deposition that is more rapid than dispensing and more flexible than pin transfer.

Adhesive printed board
Manufacturers of stencils and SMT adhesives have each responded to this need by developing new stencil technologies designed for adhesive printing, as well as printable adhesives with rheological properties suited for stencil printing.

While many board manufacturers have already been printing adhesives for SMT applications, much of the technology is not well understood.

For high-volume manufacturing applications such as automotive and consumer electronics where SMT adhesives are required for the assembly process, stencil printing of the adhesives offers the most cost effective method of manufacture. Since print cycle time is short and the board design does not change, the cost of the stencil is absorbed over the life of the product - usually one or two years.

For more information, contact Alden Johnson, Speedline Technologies, e-mail ajohnson@speedlinetech.com ; or visit http://www.speedlinetec.com .

Chart

Application Study

Successful SMT Adhesive Printing

A review of a recent Speedline Technologies customer challenge demonstrates the principles that comprise a successful SMT adhesive printing process.

Summary

Materials used:

  • Stencil: Aluminum plate, 0.125-inch thick machined and electroless nickel plated
  • Squeegee: Rheometric Pump
  • Chip Attach Adhesive: Heraeus PD 955 PR
  • Printer: Speedline AP Excel
  • Optical Microscope: Nikon
  • Height Measurement: Cyberoptics, Cyberscan 200

Challenge

Manufacturers have shown a recent interest in printing glue for adhering discrete (as well as active) components to single- and double-sided boards with cinched components. Metal and plastic have been effective in printing glue on PCBs prior to inserting through-hole components. However, there are applications where through-hole cinched components are already inserted into the board before glue is deposited.

This sequence of having the components already inserted requires a stencil that is relieved on the bottom for the cinched leads, and apertures that are in contact with the substrate to allow controlled deposits of the adhesive. Laminated stencils have been tried, but for complex designs that require adhesive dots close to cinched leads, the solid material stencil is required. This method of stencil manufacture consists of matching the relief for the cinched leads on the bottom side and then machining the apertures for glue deposit from the top side.

Print Results

See chart.

Summary

This method of stencil manufacture has produced acceptable results and shows that a stencil machined from a sheet of aluminum and coated with electroless nickel can be used to print chip attach adhesive for assemblies that have cinched leads and dense circuitry.

asi-subscribe

Related Articles

FEICA 2009: A Review

Focus On: New Technology Enables Self-Adhesive Media to be Removed Without a Trace

Review: 2004 Beijing World Adhesive Conference

Mergers and Acquisitions in Adhesives and Sealants: 2015-2016 Review and Forecast

You must login or register in order to post a comment.

Report Abusive Comment

Subscribe For Free!
  • Print & Digital Edition Subscriptions
  • eNewsletter
  • Online Registration
  • Subscription Customer Service

More Videos

Popular Stories

news generic

Dow Nets Four 2019 R&D 100 Awards

Auto-900

Sika Receives Swiss Technology Award for Structural Adhesives Designed for Lightweight Transportation Assembly

Henkel Shapeways partnership

Henkel and Shapeways to Partner for Large-Scale Industrial 3D Printing Solutions

generic chemicals

Brenntag North America Opens New Coatings & Construction Technology & Innovation Center in Pennsylvania

Dr. Dave

What is the difference between thermoplastic and thermoset adhesives?

ASI Top 20 website

Events

February 23, 2020

Adhesion Society 43rd Annual Meeting

The four-day Adhesion Society Annual Meeting offers a two-day short course, poster session, exhibition, student award symposium, and concurrent technical sessions.

January 1, 2030

Webinar Sponsorship Information

For webinar sponsorship information, visit www.bnpevents.com/webinars or email webinars@bnpmedia.com.

View All Submit An Event

Products

Handbook of Sealant Technology

Handbook of Sealant Technology

The Handbook of Sealant Technology provides an in-depth examination of sealants, reviewing their historical developments and fundamentals, adhesion theories and properties, and today’s wide range of applications.

See More Products

COVER-144px

2019 Buyers' Guide

Your comprehensive buyers’ guide for raw materials, distributors, equipment, services, and finished adhesives and sealants.

Adhesives and Sealants Magazine

asi1219COVER-144

December 2019

It's time for our annual Buyers' Guide, as well as the year's most-viewed content on our website. You won't want to miss this!

View More Create Account
  • Resources
    • List Rental
    • Ad Index
    • Classifieds & Services Marketplace
    • Want More?
    • Connect
    • Online Extras
    • Manufacturing Group
    • Privacy Policy
    • Survey And Sample
  • Subscribe
    • Print/Digital Subscription
    • eNewsletters
    • Customer Service

Copyright ©2019. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing