IMAPS PDC Webinar Series on
Wire Bonding

This four-session on-line Professional Development Course (PDC) webinar was held:
March 20, 22, 27, and 29, 2012
All webinars were held 12:00 pm - 1:00 pm EST

Registration:
IMAPS Members: $125 per webinar; 4-course series $300
Non-members: $200 per webinar; 4-course series $600

Registration Deadline: March 19, 2012

Download/Replay Webinar

Key Words

Wire bond, intermetallic, ultrasonic welding, semiconductor packaging, BGA, 3D packaging, SOP

Program Description

In 2009 more than 10^13 (10 trillion) semiconductor interconnections were wire bonded. Wire bonding is a high speed, ultrasonic welding process. In the most commonly used process, ball bonding, fine diameter (average diameter is now < 25µm) gold or copper wire is welded to a thin (1µm) Al-1%Si-0.5%Cu bond pad on the semiconductor device. Typical bond pads are now less than 75µm square and devices like graphic processors may have more than 1000 on a single device. State-of-the-art bonders now operate at rates > 16 wires/second (32 welds with high speed motions between the two welds that define the ends of each wire). Placement accuracy must be better than ± 2.5µm. It is not unusual for factories with well characterized and controlled materials and manufacturing to experience bond defect rates less than 10 ppm.

These 4 one-hour PDC lectures can be taken in total or separately depending on the experience level of the student and topics of interest.  Below is a course outline for each session.  Each session is scheduled for 50 minutes of lecture followed by 10 minutes of Q&A.

Session 1 of 4: Tuesday, March 20 -- 12:00-1:00 PM EST

In Session 1 we focus on:

• The Ball Bond Process: Step by Step Wire Bonding
• Welding
• The effect of ultrasonics on weld formation and materials properties
• Metallurgy and Intermetallics
• A comparison of the welds associated with Au-Al and Al-Cu bonding
• Au-Al failure mechanisms in ultra-fine pitch bonding

Session 2 of 4: Thursday, March 22 -- 12:00-1:00 PM EST

In Session 2 we focus on:

• The effect of wire alloying on ultra-fine pitch reliability
• Wire properties, testing and chemistry
• Pull and shear testing wire bonds
• Long term accelerated testing of wire bonds
• Reliability in fine and ultra-fine pitch bonding

Session 3 of 4: Tuesday, March 27 -- 12:00-1:00 PM EST

In Session 3 we focus on:

• Understanding wire stiffness and the effect on looping
• Wire bond loop shapes
• The second bond
• Diffusion

Session 4 of 4: Thursday, March 29 -- 12:00-1:00 PM EST

In Session 4 we focus on:

• The principal bonding variables
• Capillary design and selection for optimized processes
• Simple bond screening designed experiments
• How to optimize the bonding process

Presenter Lee is a consultant for Process Solutions Consulting, Inc. where he provides process engineering consultation and SEM/EDS/Metallography analysis. Lee’s previous experience includes 20 years as Principal and Staff Metallurgical Process Engineer at Kulicke & Soffa and Distinguished Member of the Technical Staff at Agere Systems. He currently consults for Hesse & Knipps Inc, where he is a Distinguished Member of the Technical Staff. He is also a contributing editor of Test and Packaging Times (www.taptimes.com) where he writes a column “Levine on Bonding”. He has been awarded 4 patents, published more than 50 technical papers, and in 1999 won the John A. Wagnon Technical Achievement award from the International Microelectronics and Packaging Society (IMAPs). Major innovations include copper ball bonding, loop shapes for thin, small outline packages (TSOP and TSSOP, and CSPs) and introduction of DOE and statistical techniques for understanding semiconductor assembly processes. He is an IMAPs Fellow, V.P of the Keystone Chapter, and he is a senior member of IEEE. Lee is a graduate of Lehigh University, Bethlehem, Pa where he earned a degree in Metallurgy and Materials Engineering.