-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueSupply Chain Strategies
A successful brand is built on strong customer relationships—anchored by a well-orchestrated supply chain at its core. This month, we look at how managing your supply chain directly influences customer perception.
What's Your Sweet Spot?
Are you in a niche that’s growing or shrinking? Is it time to reassess and refocus? We spotlight companies thriving by redefining or reinforcing their niche. What are their insights?
Moving Forward With Confidence
In this issue, we focus on sales and quoting, workforce training, new IPC leadership in the U.S. and Canada, the effects of tariffs, CFX standards, and much more—all designed to provide perspective as you move through the cloud bank of today's shifting economic market.
- Articles
- Columns
- Links
- Media kit
||| MENU - smt007 Magazine
Enhancing Board Level Reliability for Harsh Environments of Large WLP’s Reworkable Edgebond and Edgefill Adhesives at SMTAI 2019
August 19, 2019 | ZymetEstimated reading time: 1 minute

At the SMTA International 2019 technical conference, Portland State University and Zymet will present their investigations on enhancing the board level reliability of large WLP’s, for harsh environment applications. WLP’s, which include WLCSP’s and FO-WLP’s, offer a path to lower weight, smaller formfactor, and higher performance.
Figure 1. 12-mm WLCSP’s without adhesive (a), dot-edgebonded with reworkable edgebond adhesive (b), full-edgebonded with reworkable edgebond adhesive (c), and edgefilled with reworkable edgefill adhesive (d).
However, their low coefficient of thermal expansions is not well matched to that of commonly used organic substrates. This mis-match result in early solder joint fatigue and early failures in thermal cycle tests, tests that are more and more difficult to pass as the package gets larger and the conditions become more severe. This limitation constricts the user to using either smaller package sizes or to limiting the use of such packages to less severe environments. The investigation shows that reworkable adhesives can enhance the board level reliability of large WLP’s, even for harsh environment applications.
Thermal cycle testing from -40°C to +125°C was performed on a 12-mm WLCSP that was assembled with SAC solder on a rigid PCB. Non-bonded assemblies (Figure 1a) are compared with those bonded with a reworkable edgebond adhesive, applied in both dot-edgebond and full-edgebond configurations (Figure 1b & 1c), and with a reworkable edgefill adhesive (Figures 1d). The expected poor performance of the non-bonded package is confirmed. All three bonded configurations significantly improved performance, raising characteristic life by 300% to 1000%, depending on the configuration.
The paper, “Multi-axis Loading Effect on Edgebond and Edgefilled WLCSP Thermal Cycling Performance”, will be presented at Session APT4: Wafer Level Packaging, on Wednesday, September 25th, 2019. For more information about reworkable edgebond adhesives and edgefill adhesives, visit Zymet at Booth #941, SMTAi 2019, Rosemont Convention Center, Rosemont, IL, September 22 - 26, 2019. Or, email the company at info@zymet.com. Zymet is a global supplier of adhesives and encapsulants, focused on the development and manufacture of enabling materials for the electronics industry.
Testimonial
"The I-Connect007 team is outstanding—kind, responsive, and a true marketing partner. Their design team created fresh, eye-catching ads, and their editorial support polished our content to let our brand shine. Thank you all! "
Sweeney Ng - CEE PCBSuggested Items
Indium Corporation Promotes Two Leaders in EMEA (Europe, Middle East, and Africa) Markets
08/05/2025 | Indium CorporationWith its commitment to innovation and growth through employee development, Indium Corporation today announced the promotions of Andy Seager to Associate Director, Continental Sales (EMEA), and Karthik Vijay to Senior Technical Manager (EMEA). These advancements reflect their contributions to the company’s continued innovative efforts with customers across Europe, the Middle East, and Africa (EMEA).
MacDermid Alpha Electronics Solutions Unveils Unified Global Website to Deepen Customer, Talent, and Stakeholder Engagement
07/31/2025 | MacDermid Alpha Electronics SolutionsMacDermid Alpha Electronics Solutions, the electronics business of Elements Solutions Inc, today launched macdermidalpha.com - a unified global website built to deepen digital engagement. The launch marks a significant milestone in the business’ ongoing commitment to delivering more meaningful, interactive, and impactful experiences for its customers, talent, and stakeholders worldwide.
KOKI to Showcase Analytical Services and New HF1200 Solder Paste at SMTA Guadalajara 2025
07/31/2025 | KOKIKOKI, a global leader in advanced soldering materials and process optimization services, will exhibit at the SMTA Guadalajara Expo & Tech Forum, taking place September 17 & 18, 2025 at Expo Guadalajara, Salón Jalisco Halls D & E in Guadalajara, Mexico.
Weller Tools Supports Future Talent with Exclusive Donation to SMTA Michigan Student Soldering Competition
07/23/2025 | Weller ToolsWeller Tools, the industry leader in hand soldering solutions, is proud to announce its support of the upcoming SMTA Michigan Expo & Tech Forum by donating a limited-edition 80th Anniversary Black Soldering Set to the event’s student soldering competition.
Koh Young Appoints Tom Hattori as President of Koh Young Japan
07/21/2025 | Koh YoungKoh Young Technology, the global leader in True 3D measurement-based inspection solutions, announced the appointment of Tom Hattori as President of Koh Young Japan (JKY).