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Voiding Control for QFN Assembly

Layout of test board

Voiding Control for QFN Assembly

Quad Flat No Leads (QFN) package designs receive more and more attention in electronic industry nowadays. This package offers a number of benefits including (1) small size, such as a near die-sized footprint, thin profile, and light weight; (2) easy PCB trace routing due to the use of perimeter I/O pads; (3) reduced lead inductance; (4) easy PCB trace routing; and (5) good thermal and electrical performance due to the adoption of exposed copper die-pad technology.

These features make the QFN an ideal choice for many new applications where size, weight, electrical, and thermal properties are important.

However, adoption of QFN often runs into voiding issues at SMT assembly. Upon reflow, outgassing of solder paste flux at the large thermal pad has difficulty escaping and inevitably results in voiding.

Read Article...

Authors:	Derrick Herron, Dr. Yan Liu, and Dr. Ning-Cheng Lee
Organization:	Indium Corporation of America

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Featured New Products

Tagarno Magnus HD
Tagarno Magnus HD Inspection System
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Trident I, II, III & CL
Trident Cleanliness Tester
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Automatic systems that remove all flux and solder paste residues from post reflowed circuit... »»

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SUMMIT VERSA
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Featured auction

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April 19 | Online Auctions | X-Line Asset Management

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Pad Repair Kit

The BEST Pad Repair kit includes the tools and materials needed to reliably replace lifted or damaged surface mount and BGA pads on PCB's.

This kit includes 3 different tin plated copper base material circuit frame patterns, which offer nearly 3 times as many useable replacement land patterns as other circuit frames. Unlike dry film circuit frames, BEST circuit frames have no shelf life and can be used on both lead-free and tin-lead finish circuit boards.

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Forum

SMT Line Production Rate - Has anyone managed to accurately produce a spreadsheet or formula that will accurately calculate the amount of boards your SMT line will produce an hour?...

Solder beading with PCB from different fab - We recently decided to try using a different source for our bare boards to save money. On two different batches of PCBs now from the new source, we are seeing beading...

Gold Plating electrolytic with on BGA - I want to know difference soldering performance between gold plating electrolytic and ENIG...

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BGA X-Ray & Optical Inspection Criteria Webinar 14.30GMT

Online Webinar | Mon, April 4 | Sponsored by: ASKbobwillis.com

The workshop covers optical and x-ray inspection of solder joints for both tin/lead and lead-free terminations....

Interactive PCB Inspection Lab

Seminar/Course, Fri, April 8 | Sponsored by: EPTAC Corporation

This course will provide the students with an inspection process to physically review the product to determine the whether or not it meets the customer quality requirements....

IPC APEX EXPO 2011

Trade Show/Exhibition, Conference | Sun, April 10, 2011 - Thu, April 14 | Sponsored by: IPC

Join thousands of colleagues from more than 50 countries at our industry's premier event � featuring advanced and emerging technologies in printed board design and manufacturing, electronics assembly and test...

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Career Center

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Company: Dunhill Professional Staffing

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Company: KBC Electronics

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Industry Associations Events

SMTA - Surface Mount Technology Association is a non-profit international association of companies and individuals (totalling 4,000) involved in all aspects of advanced electronics assembly, surface mount and related technologies. Membership Info | SMTA Certification | Bookstore

Next Event: 15th Annual Atlanta SMTA EXPO - April 21

IPC - Association Connecting Electronics Industries is a US-based trade association dedicated to the competitive excellence and financial success of its nearly 2,600 member companies which represent all facets of the electronic interconnection industry, including design, printed wiring board manufacturing and electronics assembly. Membership Info | Training & Certification Programs | Standards & Publications - Online Store

Next Event: Advanced Designer Certification Workshop and Exam (CID+) in conjunction with IPC APEX EXPO - April 8-10

SMTnet Express
April 7, 2011

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