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Design and Assembly Process Challenges for Bottom Terminations Components (BTCs)

Presenter: Ray Prasad
Company: Ray Prasad Consultancy Group
Date Published: 1/15/2013

Description: Overview:
Bottom Termination surface mount Components (BTCs) go by various names such as QFN, DFN, SON, LGA, MLP, and MLF, which utilize surface to surface interconnections. BTCs are like BGAs which also have hidden terminations, but they are also very different. BTCs do not have spheres but rather metallized terminations or pads underneath the package. This minor difference in the physical I/O shape makes all the difference in design, assembly and rework between BTCs and BGAs.

Since there are no leads or balls in BTCs to take up any slack from package or board warpage, you essentially need perfection in design and assembly process. When was the last time you saw every thing perfect on any manufacturing floor?

One must also keep in mind that these parts are not the only components that must be mounted on the board. Look at any board. It will have other packages such as BGAs, fine pitch and even some through-hole components; and those components have their own unique design and assembly implementation requirements. So designing for BTCs may involve trial and error and lot of frustration by many companies. Additional frustration is caused by fast-paced changes in packaging technologies and the advent of Lead Free has compounded the designer’s task.

When it comes to inspection, BTCs pose even more challenge than BGAs. What you may see in visual inspection may look bad but may really be acceptable. And what you don’t or can’t see may really be critical. And the fact that the Process Engineer must worry about both too much solder and too little solder on the same BTC package makes the quality engineer nervous about field returns.

What You Will Learn:
Sept 6th
  • Introduction
  • Pros and Cons of BTC
  • Pull Back Vs Non Pull Back
  • BTC Package Manufacturing Process
  • Major Design Considerations for BTCs
  • Laminates and Surface Finish Considerations
  • Land Pattern and Stencil Design Guidelines
  • Component considerations

    Sept 13th
  • Assembly Process Guidelines for BTC
  • Solder Paste Printing- the Key Process Step
  • Reflow Process Guidelines
  • BTC Solder Joint Quality Requirements
  • BTC Rework Process
  • Key strategies in design and manufacturing processes to prevent field returns

    Who Will Benefit:
    The target audiences for this course are managers, design, process and quality engineers, and operators and technicians who deal with the electronic design, assembly, inspection, and repair processes. The intent is to provide useful and practical information to those are using or considering tin/lead or lead-free processes for assembly of BTCs. Anyone in process, quality, manufacturing, design, purchasing and management who wants to get a good understanding of design and manufacturing issues in BTCs for building assemblies in-house or at a subcontractor will benefit from this course.

    About The Instructor:
    Ray Prasad is the founder of Ray Prasad Consultancy Group. Before starting his consulting practice in 1994, Mr. Prasad held key technology positions at Boeing and Intel for 15 years. He was the SMT Program Manager at Intel responsible for developing and implementing SMT for the system products. He also developed and taught DFM and SMT manufacturing courses to Intel engineers. For establishing the SMT infrastructure at Intel he was recognized by Intel CEO Andy Grove. He also managed the Intel PentiumProTM package program for Intel and introducing SMT into Boeing airplanes when he served as a lead engineer at that company.

    Author of the text book Surface Mount Technology: Principles and Practice published by Walter Kluwer Academic Publishers and over 100 papers, Mr. Prasad holds two patents in BGA and is a popular workshop leader for in depth SMT, BTC, BGA/CSP and Lead free professional courses at national and international conferences and in major OEM and EMS companies.

    Mr. Prasad received his BS in Metallurgical Engineering from the Regional Institute of Technology, Jamshedpur in India and MS in Materials Science and Engineering and MBA from the University of California at Berkeley, USA. He is a registered Professional Metallurgical Engineer.

  • Key Words: 

    BTC, Challenges, Design, Assembly

      Members: $200.00 (Log on to receive the member rate)
      Non-Members: $300.00

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