Electronics Assembly Knowledge, Vision & Wisdom
Stencil Design for Ultra Fine Pitch Printing
Stencil Design for Ultra Fine Pitch Printing
Miniaturization is pushing the stencil printing process. As features become smaller, solder paste transfer efficiency is becoming more critical.
Production Floor

Authored By:
Mark Whitmore, Jeff Schake & Clive Ashmore
DEK Printing Machines Ltd
11 Albany Road, Weymouth
Dorset, DT4 9TH, UK
,{url:'http://www.circuitinsight.com/videos/stencil_design_ultra_fine_pitch_printing.mp4'},{url:'http://www.circuitinsight.com/videos/programs_final.mp4'}], clip:{autoBuffering:true, autoPlay:true, scaling:'scale' } }).ipad();
Summary
Miniaturization is pushing the stencil printing process. As features become smaller, solder paste transfer efficiency is becoming more critical.

In latest research work, actual paste deposit volumes and transfer efficiency have been monitored and compared for both square and round apertures with area ratio's ranging from 0.20 thru to 1.35. This covers apertures sizes of between 100 and 550 microns in a nominal 100 micron thick stencil foil. In addition, the effect of ultrasonically activated squeegees (ProActiv) has been assessed as part of the same experiment.

A further comparison has also been made between type 4 and type 4.5 solder paste as well. The data presented here will help provide guidelines for stencil aperture designs and strategies for ultra-fine pitch components such as 0.3CSP's.
Conclusions
The next generation of ultra fine pitch components will place extreme demands on the stencil printing process. The requirement for printing solder paste through stencil apertures with area ratios below 0.5 will become common place.

The data presented here indicates that with judicial choice of stencil design and materials it will be possible for designers to work with aperture area ratios down to 0.4. To optimise a process it is becoming increasingly important that an engineer has a good understanding of stencil aperture design specification, material properties and process options/aids available to him.

The interactions between all of these facets is becoming more complex and critical to the successful implementation of a process.
Initially Published in the SMTA Proceedings
Submit A Comment

Comments are reviewed prior to posting. Please avoid discussion of pricing or recommendations for specific products. You must include your full name to have your comments posted. We will not post your email address.

Your Name


Company


E-mail


Country


Comments


Authentication

Please type the number displayed into the box. If you receive an error, you may need to refresh the page and resubmit the information.



Related Programs
bullet Selective Printing for BGA Components
bullet Assembly Options for Handheld Products
bullet Assembling Boards with BGAs on Both Sides
bullet Problems to Look for with Crimp Terminations
bullet How to Clamp Odd Shaped Circuit Boards
bullet Assembly and Reliability Investigation of PoP
bullet Evaluation of Stencil Materials, Suppliers and Coatings
bullet What is Solder Paste Working Life on a Stencil?
bullet How To Calculate Component Standoff Height
bullet Humidity Inside Our Screen Printer
More Related Programs
About | Advertising | Contact | Directory | Directory Search | Directory Submit | Privacy | Programs | Program Search | Sponsorship | Subscribe | Terms

Circuit Insight
6 Liberty Square #2040, Boston MA 02109 USA

Jeff Ferry, Publisher | Ken Cavallaro, Editor/Business Manager

Copyright © Circuitnet LLC. All rights reserved.
A Circuitnet Media Publication