-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueMechatronics
Our expert contributors discuss the advent of mechatronics in PCB design, the challenges and opportunities this creates for circuit board designers, and the benefits—to the employee and the company—of becoming a mechatronics engineer.
Creating a Culture of Collaboration
PCB designers could learn quite a bit from NASA and the private companies that develop spacecraft: Every one of these vehicles is a testament to the value of collaboration among disparate stakeholders. Without a collaborative culture, the rocket might never get off the ground.
Breaking High-speed Material Constraints
Do you need specialty materials for your high-speed designs? Maybe not. Improvements in resins mean designers of high-speed boards can sometimes use traditional laminate systems. Learn more in this issue.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - design007 Magazine
Happy Holden on Gerry Partida’s ‘Significant’ Microvia Reliabilty Paper
December 30, 2022 | Happy Holden, I-Connect007Estimated reading time: 2 minutes
![](https://iconnect007.com/application/files/4417/1686/6064/happy_holden_col_300.jpg)
Gerry Partida, vice president of technology at Summit Interconnect, authored a technical paper, “Next Progression in Microvia Reliability Validation—Reflow Simulation of a PCB Design Attributes and Material Structural Properties During the PCB Design Process,” at IPC APEX EXPO 2022, and it’s worth revisiting. This significant paper on microvia reliability validation provides a summary of what’s been happening in the microvia fabrication arena, especially regarding the issue of latent defects in stacked microvias. The paper is available for download here.
Partida offers a thorough look at the controversy initiated in 1996 when latent electrical defects began showing up in field-deployed boards using microvias. My familiarity with this topic dates to 2000, when IPC organized round robin testing of microvia technologies. All looked good, and HDI technology took off. As evolution would have it, the technology grew and diversified. But all the new variants were not necessarily tested like the initial round in 2000.
As Gerry summarizes, “Today, the industry is facing a similar challenge with microvia reliability, especially after reflowing of the PCB at assembly, during rework, or operating in the field. As with the shortcomings of electrical testing in the past, the industry designed PCBs with microvias without evaluating the thermal properties of the material or the geometries in the design. Fabricators produced the finished goods and evaluated the finished PCB to established performance standards such as IPC-6012. When difficult-to-detect failures occurred post assembly, a test method IPC-TM-650 2.6.27 was established and a caution was added to the IPC- 6012 Rev E in Section 3.6, Structural Integrity. The testing of a D coupon via IPC-TM-650 2.6.27 did validate that the finished PCBs were safe for assembly, but it did not stop a fabricator from building a bad design.”
Many studies have shown that the failures seem to be initiated at the interface of the microvia target pad and the plated microvia interface—a plain “butt joint.” As the elevated temperature of lead-free assembly reflow is employed, the stress on this joint exceeds what it can accommodate, unlike tin-lead reflow that occurs at a lower temperature. What caught us unprepared is that after reflowing, the joint appears to be okay and will pass other performance testing, waiting until it fails in the field. This explanation seems to be validated by research that iMEC in Europe has conducted for the European Space Agency. Their finite element analysis of the microvia structure shows the maximum stress at this location and the stress increases as you stack the microvias and increase the temperature.
To read this entire article, which appeared in the November 2022 issue of Design007 Magazine, click here.
Suggested Items
Dymax Expands Core Market Focus to Include the Energy Sector
07/24/2024 | DymaxDymax, a leading manufacturer of rapid curing materials and equipment, announces a curated lineup of light-curable adhesives and coatings designed to meet the complex assembly needs of stationary energy storage systems such as industrial gas turbines (IGTs) and various types of fuel cells and electrolyzers including Solid Oxide (SOFC) and Proton Exchange Membrane (PEMFC).
The Knowledge Base: The Value of Industry Certifications
07/24/2024 | Mike Konrad -- Column: The Knowledge BaseIndustry certifications have become increasingly significant in the modern job market, offering a range of benefits to both individuals and employers. These certifications serve as formal recognitions of expertise and proficiency in specific areas, validating a person's skills and knowledge. In the context of the electronics assembly industry, certifications are particularly valuable, given the technical nature of the work and the rapid advancements in technology.
Do You Collaborate With Your Component Supplier?
07/15/2024 | Andy Shaughnessy, Design007 MagazineMention the word “collaboration” to a group of designers, and a few of them might acknowledge working closely with their fab and assembly partners. But how many designers consider their component providers to be true stakeholders in the process and collaborate with them regularly? Duane Benson, founder of Positive Edge, has a long history of working on the component side of things. I asked Duane to weigh in with his thoughts on collaborating with component suppliers.
CIL Improves its RAPID PCB Assembly Service with a Dedicated SMT Line
06/27/2024 | CILIn recent months much of CIL’s activities have been concentrated on its Semiconductor packaging and volume PCB assembly capability from its BP2 facility.
IPC WorksAsia – Quality & High Reliability Conference Thailand
06/26/2024 | IPCQuality & High Reliability are critical when electronics assemblies are working in harsh environments where there is high temperature difference, vibration; and components get smaller and demand for high reliability products increases.