Estimated reading time: 1 minute

SMT Solver: Developments in BTC Guidelines: IPC-7093A, Pt. 1

If you attended the IPC-7093 meeting at IPC APEX EXPO 2020, you know that we completed the revision of this document and are now in the process of balloting it for final release within a couple of months.

As the chair of this IPC committee, let me share the latest developments in bottom-terminated component (BTC) design and assembly guidelines in this three-part series. In this first column, I will give you an overview of this technology and standard. In my upcoming columns, I will take an in-depth look at the design, assembly, quality, and reliability issues in BTC technology that have been incorporated in this latest IPC-7093A revision.

Let me start by thanking all the team members of this committee. Special thanks to A-team members Matt Kelly (IBM, now IPC), Mark Jeanson (IBM), Udo Welzel (Bosch), Robert Cochran (Mindchasers), David Hillman (Collins Aerospace), Michael Johnson (MACOM), Rob Rowland (Axiom), and Dr. Raiyo Aspandiar (Intel). These members put in countless hours attending numerous meetings and writing and rewriting various sections and reviewing other comments. Most important of all, this team was fortunate to have Chris Jorgensen as our IPC liaison, who kept us on our toes and nudged everyone to keep up with their commitments. Thanks to these people and many others, who made this a much better and more up-to-date document than the previous version.

What Are BTCs?

BTCs have many names. Examples of BTCs include small-outline no-leads (SONs), dual-flat no-leads (DFNs), quad-flat no-leads (QFNs), land-grid arrays (LGAs), etc. Here is another way to think of BTCs. We are all very familiar with ball-grid arrays (BGAs). BTCs are like BGAs without the balls. Think of BTCs as a poor man’s BGAs because BGA is the most expensive package, and BTC is the least expensive package. This minor difference in physical construction makes all the difference in cost, design, assembly, and rework between BTCs and BGAs.

To read this entire column, which appeared in the March 2020 issue of SMT007 Magazine, click here.