Research
Leadless Flip Chip PLGA for Networking Applications
Influence of Manufacturing Quality on Thermomechanical Stress of Microvias
Designing a High Performance Electroless Nickel and Immersion Gold
Innovative of CU Electroplating Process for Any Layer Via Fillwith Planer Via Top and Thin Surface Copper
Acoustic Micro Imaging Analysis for 3D Packages
Conformal Coatings in Preventing Resistor Silver Sulfide Corrosion
Rework Challenges for Leading Edge Components BGA, QFN and LED
Compatibility and Aging for Flux and Cleaner Combinations
MORE RESEARCH
Latest Industry News
Globalization strikes back
Self-driving technology reaches a crossroads
The Art of Wanting Less
Amazon is everywhere. Here's how the US could break it up
The Best Laptops 2021
Foxconn installs advanced packaging equipment at China plant
Foxconn installs advanced packaging equipment at China plant
Here’s the latest proof that Apple is fixing the iPhone notch
MORE INDUSTRY NEWS

Stencil Aperture Design for Next Generation Ultra Fine Pitch Printing



Stencil Aperture Design for Next Generation Ultra Fine Pitch Printing
The work reported here represents the start of a series of experiments to help further understand the significance of square vs circular aperture formats.
Production Floor

DOWNLOAD

Authored By:


Mark Whitmore, Jeff Schake & Clive Ashmore
DEK Printing Machines Ltd
11 Albany Road, Weymouth
Dorset, DT4 9TH, UK

Summary


Miniaturisation 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 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 aswell.

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

Comments

No comments have been submitted to date.

Submit A Comment


Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name


Your Company
Your E-mail


Your Country
Your Comments



Board Talk
What Causes Solder Icicles During Wave Soldering
Modify Rework Procedures for Assemblies Fabricated Using OSP?
Can High Particle Concentrations Impact PCB Assembly?
Review of Tin-Copper and Tin-Nickel Intermetallic Thickness
Moisture Barrier Bag Issues
Trouble With Skewed DPAK Components
Can Mixing Wave Solder Pallets Cause Contamination?
How to Reduce Voiding on QFN Components
MORE BOARD TALK
Ask the Experts
Suggested Limit for PCBA Heat Cycles
Average Temperature/Humidity for an Electronics Assembly Facility?
ENIG Solderability Issues
Very Low Temp PCBs
0201 Pick & Place Nozzle Plugging
IPC-A-610 Class 3 - IPC-A-600 Class 2
BGA Solder Ball Collapse
Baking After Cleaning Hand Placed Parts
MORE ASK THE EXPERTS