Design and Assembly Challenges of BTC
 About This Course
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.
The objective of the course is to get away from the trial and error approach and provide you successful design and process practices commonly used by the industry. This course will cover the practical details of BTC design and assembly processes.
This course is based on Surface Mount Technology: Principles by Ray Prasad and Practice and IPC 7093 Design and Assembly Process Guidelines for BTCs also co-chaired Ray. This course identifies many of the characteristics that influence the successful implementation of robust and reliable BTC assembly processes.
This is not a theoretical course. It s based on Mr. Prasad's over two decades of experience at Boeing, Intel and numerous clients and deals with "real-world" problems in lead free and tin-lead BTC implementation.
How You Will Benefit
After completing this course you will be able to:
Get an overview of various types of BTCs such as QFN, MLF, LGA etc followed by Technical details on BTC design, assembly and reliability issues.
Troubleshoot BTC design and manufacturing problems.
Get a handle on two most critical issues in BTC assembly- solder paste printing and rework.
Learn about the cost effective way to design for both tin-lead and lead free products.
Topics Covered
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
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
Who Should Attend
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.
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