-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueComing to Terms With AI
In this issue, we examine the profound effect artificial intelligence and machine learning are having on manufacturing and business processes. We follow technology, innovation, and money as automation becomes the new key indicator of growth in our industry.
Box Build
One trend is to add box build and final assembly to your product offering. In this issue, we explore the opportunities and risks of adding system assembly to your service portfolio.
IPC APEX EXPO 2024 Pre-show
This month’s issue devotes its pages to a comprehensive preview of the IPC APEX EXPO 2024 event. Whether your role is technical or business, if you're new-to-the-industry or seasoned veteran, you'll find value throughout this program.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
SJIT, Solder Joint Integrity Test, To Find Latent Defects in Printed Wiring Board Assembly
April 29, 2015 | Hiroshi Yamazaki, Hioki E.E. CorporationEstimated reading time: 5 minutes
Latent defect test
The defects that come out after a PWBA is delivered to customers are called "Latent defect". In automotive industries for example, latent defect may happen if any solder joint is not complete. While driving a car, the PWBA inside suffers vibration and the solder joint without solder or with insufficient solder may become complete open.Thus even though there is not a failure in an initial stage, defect happens sometimes after long time due to a latent effect.
Basics of SJIT, Solder Joint Integrity Test
The purpose of SKIT is to find latent defects. There are some ways to find IC pin opens, but conventional capacitive, magnetic and diode methods cannot find latent pin opens. Also, boundary-scan test can find IC pin opens, but cannot find latent pin opens. X-ray test can find latent pin opens, but it is too slow to test a whole board assembly.
The only practical way to fine latent defects is 4-wire resistance measurement method.. The less the volume of solder is, the more resistance becomes. By measuring resistance across solder joint, therefore reliability of solder joint can be tested.
Case studies of SJIT
In the following pages, some solder conditions and measured resistance are shown.
Conclusion
Repair cost enormously increases if a defect is found in downstream. It is called "The 10X rule in PWBA tests". This rule means that PWBAs need to screen out defectives in an early stage by structural tests.
Even if a defect is found in the market, recall cost can be 1million times or more, so in the structural test at the assembly factory, need to screen out latent defectives as well.
SJIT, Solder Joint Integrity Test, is to find latent defects, and 4-wire resistance measurement method is the only way to find them at the moment
References
[1] Hiroshi YAMAZAKI, "Key Drivers and Challenges for Electronics Packaging Test and Inspections", The Japan Institute of Electronics Packaging, Vol. 14, No. 1, 2011, pp. 26-30
[2] Koji UCHIYAMA, "Preparation for Test/Inspection Economical Scale", The Japan Institute of Electronics Packaging, Vol. 14, No. 2, 2011, pp. 103-108
Editor's Note: This article was originally presented at the 2014 IPC APEX EXPO Technical Conference Proceedings.
Page 2 of 2Suggested Items
Indium Experts to Present on High-Temperature, Lead-Free Solder Paste and High Reliability Liquid Metal Alloys Poster at ECTC
05/16/2024 | Indium CorporationIndium Corporation Research Associate Kyle Aserian will deliver a presentation at the 74th Electronic Components and Technology Conference (ECTC) on May 31, in Denver, Colorado.
Indium Experts to Present at Electronics in Harsh Environments SMTA Conference
05/13/2024 | Indium Corporationndium Corporation Technical Manager for Europe, Africa, and the Middle East, Karthik Vijay, will deliver a technical presentation and Indium Corporation Senior Technologist, Dr. Ronald Lasky, will deliver both a workshop and technical presentation at the Electronics in Harsh Environments SMTA Conference on May 14-16 in Copenhagen, Denmark.
Connect the Dots: Designing for Reality—The Pre-Manufacturing Process
05/08/2024 | Matt Stevenson -- Column: Connect the DotsI have been working with Nolan Johnson on a podcast series about designing PCBs for the reality of manufacturing. By sharing lessons learned over a long career in the PCB industry, we hope to shorten learning curves and help designers produce better boards with less hassle and rework. Episode 2 deals with the electronic pre-manufacturing process. Moving from CAD (computer-aided design) to CAM (computer-aided manufacturing) is a key step in PCB manufacturing. CAM turns digital designs into instructions that machines can use to actually build the PCB.
AIM Solder Signs Shinil Fl Ltd. as New Distributor for Korea
05/08/2024 | AIM SolderAIM Solder, a leading global manufacturer of solder assembly materials for the electronics industry, is pleased to announce a new distribution partnership with Shinil Fl Ltd., a prominent supplier of technological solutions in the SMT and semiconductor sectors.
Indium Corporation to Showcase HIA Materials at ECTC
05/07/2024 | Indium CorporationAs an industry leader in innovative materials solutions for semiconductor packaging and assembly, Indium Corporation® will feature its advanced products designed to meet the evolving challenges of heterogeneous integration and assembly (HIA) and fine-pitch system-in-package (SiP) applications at the 74th Electronic Components and Technology Conference (ECTC), May 28‒31, in Denver, Colorado.