Issued Date: 2014/08/11
Issued By: iST
For ongoing telecom (4G/LTE and base station) and cloud computing era, global leading lab-service company- iST unveils Acoustic Emission Test (AE test) to evaluate the quality and reliability of Printed Circuit Board using on above field. This testing method can assist PCB manufacturer and PCB assembler, whose products are used in 4G base station, server and cloud computing with larger and thicker multilayer requirements, to determine which Copper Clad Laminate (CCL) is most suitable for withstanding PCB pad cratering.
Pad cratering, is a microcrack or fracture underneath the pad of a surface mount component. Most commonly occur on high-frequency and high-speed PCB which are used in the telecom industry. In general, the characteristic of high-frequency and high-speed material has weaker bonding strength with Cu in comparison with normal dielectrics material. In addition, in order to satisfy lead free assembly and halogen free compliance, the material will be prone to stiffer and more brittle which would result in higher propensity of PCB pad cratering during PCB assembly and in service life, especially when assembling with larger size package like BGA and QFN.
However, PCB pad cratering defect is hard to be found through electrical test and visual inspection. The internal microcrack sometimes would not induce electrical failure. Most ODM/EMS manufacturers cannot know whether there is microcrack generated underneath the pad in the PCB before product shipping.
“If the end product with pad cratering is adopted in the market as normal product, it could not show any problem in the short term. However, in the long term, it could cause significant effects on the reliability of product operation, especially when those products are designed for high reliability with stringent requirements as well as long term service life more than 7 to 10 years, such as telcom, server and cloud computing product.” Jeffrey Lee, Assistant Vice President of Global Engineering Development Division of iST, said.
In order to find out PCB pad cratering in early phase, iST cooperate with international telecom firm and IPC (Association Connecting Electronics Industries) to develop Acoustic Emission testing method. In the end of 2013, IPC published Standard IPC 9709 for AE test guide. iST formally introduce AE test to our customer for product quality validation.
In general, Acoustic Emission testing method is used in earthquake monitoring and material strength testing in architecture/ aeronautic field. However, iST apply AE testing method in PCB validation field. Use four sensors to detect the acoustic emission events generated during board level bending test. It can plot out all position generating pad crater in whole PCB and quantify corresponding failure energy level. Hence, PCB manufacturers and PCB assemblers can differentiate the performance withstanding pad cratering among various PCB materials by adopting AE/ bending test method.
Acoustic Emission testing method can help PCB manufacturers and PCB assemblers make quick decision in CCL material selection for pad cratering resistance. If you have any further inquiry, please contact Mr. Jeffrey Lee +886-3-579-9909 #3202; Mr. Mark Chen #3202.
About Integrated Service Technology
Founded in 1994, iST began its business from IC circuit debugging and modification and gradually expanded its scope of operations to include failure analysis, reliability verification, material analysis, and quality assurance. Through the years, iST has constructed a comprehensive verification and analysis engineering platform, offering full-scope services to the IC engineering industry. iST customers cover the whole spectrum of the electronics industry from IC design to end products.
In response to rising environmental awareness, iST not only focuses on its core services but is also expanding its service offerings based on international trends. iST’s lead-free and halogen-free verification testing, chemical quantitative testing and signal integrity services have all been accredited by multiple international independent third-party organizations including TUV NORD Germany and BSI UK. With increased outsourcing by major international brands, iST now also plays the role of independent quality testing laboratory for OBM outsourcing products and is certified by Dell, Cisco, Delphi, Continental Automotive and Lenovo.
Headquartered in Hsinchu, iST’s pursuit of precision, perfection and efficiency has led it to expand its operations around the world. The iST Group now includes iST Kunshan, iST Shanghai, iST Beijing and iST Shenzhen in China, IC Service in Japan, and an iST laboratory in the US. These are all dedicated to providing customers with prompt, reliable and high-quality technical services in order to grow with the leaders of the world. For more information, please visit the iST website at:www.istgroup.com