Laser Ultrasonic Inspection of Solder Bumps in Flip Chip Packages Using Virtual Package Device as Reference

2010 ◽  
Author(s):  
I. Charles Ume ◽  
Jie Gong ◽  
Razid Ahmad ◽  
Abel Valdes
Keyword(s):  
Time Domain ◽  
Flip Chip ◽  
Electronic Device ◽  
Ultrasonic Inspection ◽  
Reference Method ◽  
Ultrasonic Waves ◽  
Quality Analysis ◽  
Inspection System ◽  
Solder Bumps

Flip chip package is widely used in the electronic device manufacturing industry. The top side of a flip chip device is manufactured with solder bumps. The device is then flipped on its top so that the solder bumps can be bonded to a substrate, forming the mechanical and electrical connection between the device and substrate. As a result, the solder bumps are sandwiched between the silicon die and the substrate, making them no longer visible for usual inspection. A novel solder joint inspection system capable of evaluating the quality of the hidden solder bumps on a flip chip package has been developed using laser ultrasound techniques. The system pulses a laser onto the top surface of a chip package to generate ultrasonic waves in the package and excite structural vibrations which can then be measured using an interferometer. Since defective solder bumps cause changes in the transient vibration response of a tested sample, quality of the tested sample can be assessed by correlating its vibration responses to that of a known good device. A limitation of this implementation is the necessity of a known-good reference chip package, which typically involves expensive testing using alternate methods. In this paper, the development of a method capable of generating a virtual reference chip package is presented. This method, called Hybrid Reference Method, uses a statistical approach to find which packages in a sample set are most similar and then averages their time domain signals to generate a virtual chip package, known as the Hybrid Reference Package. The signals associated with Hybrid Reference Package are then correlated with the time domain signals obtained from the packages under inspection to obtain a quality signature. Finally, defective and non-defective chip packages are separated by estimating a beta distribution that fits the quality signature histogram of the inspected packages and then determining a cutoff threshold for an acceptable quality signature. This method was applied to two types of flip chip packages where no pre-established known-good reference package was available. The results of this quality analysis were validated by comparison with electrical test and X-ray results.

Underfill Dispensing for 3D Die Stacking with Through Silicon Vias

2012 ◽  
Vol 2012 (1) ◽  
pp. 000548-000553 ◽  
Author(s):  
Fuliang Le ◽  
S. W. Ricky Lee ◽  
Jingshen Wu ◽  
Matthew M. F. Yuen
Keyword(s):  
Flip Chip ◽  
Through Silicon Vias ◽  
Flip Chips ◽  
Solder Bumps ◽  
Die Stacking ◽  
Chip Carrier ◽  
On Chip ◽  
Silicon Vias ◽  
3D Package

In this paper, a 3D stacked-die package is developed for the miniaturization and integration of electronic devices. The developed package has a stacked flip-chip-on-chip structure and eight flip chips are arranged in four vertical layers using four silicon chip carriers with through silicon vias (TSVs). In each layer, two flip chips are mounted on the silicon chip carrier with 100 um solder bumps, and multiple TSVs are fabricated in each silicon chip carrier for underfill dispensing purpose. The 3D module with four stacked layers is sequentially assembled by the standard surface mount reflow process and finally mounted to a substrate. In the underfill process, conventional I-pass underfill is used to fill up the gaps of the bottom two layers as it has relatively fast spreading speed. For the top two chip carriers, underfill is dispensed through TSVs to fill the gaps. Unlike the conventional underfill process, the encapsulant in this case would not flow in the gaps by the capillary effect unless the dispensed materials can obtain enough kinetic energy to overcome the surface tension at the end of TSVs, and thus, smooth sidewall, proper dispensing settings and optimized TSV pattern are needed. After underfill, detailed inspections are performed to verify the quality of encapsulation. The results show that the combined I-pass/TSV underfill process gives void-free encapsulation and perfect fillets for the stacked 3D package.

Research about Online Inspection System for the Assembly Quality of Automobile Gearbox Sliding Bracket

2010 ◽  
Vol 152-153 ◽  
pp. 368-371
Author(s):  
Chun Dong Zhu ◽  
Fei Guo ◽  
Bo Wei
Keyword(s):  
Quality Management System ◽  
Good Condition ◽  
Quality Analysis ◽  
Inspection System ◽  
Central Control ◽  
Assembly Quality ◽  
Online Inspection ◽  
Qualification Rate ◽  
Central Control System

Gearbox sliding bracket is an important component of Automobile Gearbox. Because it has many parts which have little difference in shape and size, it is very easy to make mistake in assembly parts of this component. Due to mass production, it is high time to develop an online inspection system for the aseembly quality. Analysis the assembly characteristic of the component, this paper develop an online inspection system which is mainly composed of a central control system(CCS) and a sensor. Under the command of the CCS, the sensor is able to automatically inspect the component’s parts of which are wrong assmbly, reverse assembly and missing assmbly. Also the sensor can send the inspection information to the CCS. Subsequently, the CCS judges the information and dispalys the judgment result in time. At the same time, through the network, it is able to send the assembly quality information to the enterprise quality management system, such as the eligible amount, the reject amount, the qualification rate. This online automatic inspection system has run in good condition since it was officially put into operation at 2007 and its accuracy comes up to 100%.

scholarly journals Measurement Capability of Laser Ultrasonic Inspection System for Evaluation of Ball-Grid Array Package Solder Balls

2021 ◽  
Vol 18 (4) ◽  
pp. 183-189
Author(s):  
Vishnu V. B. Reddy ◽  
Jaimal Williamson ◽  
Suresh K. Sitaraman
Keyword(s):  
Flip Chip ◽  
Ultrasonic Inspection ◽  
Reference Sample ◽  
Ball Grid Array ◽  
Inspection System ◽  
Laser Ultrasonic ◽  
Fiber Array ◽  
Measurement Capability ◽  
Repeatability And Reproducibility ◽  
Ball Grid Array Packages

Abstract Laser ultrasonic inspection is a novel, noncontact, and nondestructive technique to evaluate the quality of solder interconnections in microelectronic packages. In this technique, identification of defects or failures in solder interconnections is performed by comparing the out-of-plane displacement signals, which are produced from the propagation of ultrasonic waves, from a known good reference sample and sample under test. The laboratory-scale dual-fiber array laser ultrasonic inspection system has successfully demonstrated identifying the defects and failures in the solder interconnections in advanced microelectronic packages such as chip-scale packages, plastic ball grid array packages, and flip-chip ball grid array packages. However, the success of any metrology system depends upon precise and accurate data to be useful in the microelectronic industry. This paper has demonstrated the measurement capability of the dual-fiber array laser ultrasonic inspection system using gage repeatability and reproducibility analysis. Industrial flip-chip ball grid array packages have been used for conducting experiments using the laser ultrasonic inspection system and the inspection data are used to perform repeatability and reproducibility analysis. Gage repeatability and reproducibility studies have also been used to choose a known good reference sample for comparing the samples under test.

Digital Signal Processing in a Novel Flip Chip Solder Joint Defects Inspection System

2003 ◽  
Vol 125 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Sheng Liu ◽  
I. Charles Ume
Keyword(s):  
Signal Processing ◽  
Solder Joint ◽  
Time Domain ◽  
Flip Chip ◽  
Signal To Noise Ratio ◽  
Digital Signal ◽  
Inspection System ◽  
Spectrum Estimation ◽  
Joint Quality ◽  
Signal Processing Methods

Digital signal processing methods in a novel flip chip solder joint quality inspection system are presented. Laser ultrasound and interferometric system is a new approach for solder joint inspection. It has many advantages such as being noncontact, nondestructive, fast, accurate and low cost. Furthermore, it can be used on-line in assembly line or off-line during process development. In this system, signals recorded are ultrasound waveforms. Because noise is present, signal processing methods are developed to increase signal-to-noise ratio, and to extract solder joint quality information from those waveforms. Signals are analyzed both in frequency domain and time domain. In the frequency domain, digital filtering and Bartlett power spectrum estimation method are used, and defects can be detected from the frequency shifting. A series of experimental results are presented, showing that power spectrum estimation can greatly increase the signal-to-noise ratio than when only time domain averaging is used. This speeds up the data acquisition and analysis process. In the time domain, “error ratio” is used to measure the difference between a good chip and a chip with defect. Results indicate that error ratio method not only can detect whether a chip has solder joint defect or not, but can also locate that defect. Overall, signal processing plays a very important role in this flip chip quality inspection system.

Application of a Novel Flip Chip Solder Joint Inspection System to Chips on an FR-4 Substrate

2000 ◽  
Author(s):  
Dathan S. Erdahl ◽  
Sheng Liu ◽  
I. Charles Ume
Keyword(s):  
Solder Joint ◽  
Flip Chip ◽  
Solder Bump ◽  
Solder Joints ◽  
Inspection System ◽  
Vibration Displacement ◽  
Manufacturing Defects ◽  
Flip Chips ◽  
Solder Joint Inspection

Abstract Because the trend in electronic interconnection technology is toward the development of solder bump technologies, that include flip chips, chip scale packages, multi-chip modules (MCMs), and ball grid array (BGA) packages, solder bump inspection methods must be developed to allow rapid, accurate, and high resolution on-line inspection of joint quality. Although traditional methods can detect some manufacturing defects, they do not actually test the mechanical quality of the connection. A novel solder-joint inspection system has been developed based on laser ultrasound and interferometric techniques. A pulsed laser generates ultrasound on the chip’s surface and the whole chip is excited into vibration modes. An interferometer is used to measure the vibration displacement of the chip’s surface. Solder joints with different qualities cause different vibration responses, acting as constraints on the system. The system was used to inspect the quality of solder joints on a group of flip chips mounted on FR-4 substrates, and the results show the ability of the system to detect defects such as missing solder balls, cracked chips, and gross misalignment.

Особенности проведения неразрушающего контроля полимерных и композиционных материалов с использованием бесконтактной ультразвуковой стимуляции и лазерного вибросканирования

2021 ◽  
pp. 14-23
Author(s):  
В.Ю. Шпильной ◽  
В.П. Вавилов ◽  
Д.А. Дерусова ◽  
Н.В. Дружинин ◽  
А.Ю. Ямановская
Keyword(s):  
Nondestructive Testing ◽  
Ultrasonic Inspection ◽  
Inspection System ◽  
External Influence ◽  
Laser Vibrometry ◽  
Experimental Procedure ◽  
Acceptable Quality ◽  
Stimulation Technique ◽  
Magnetostrictive Transducer

Until present, air-coupled (non-contact) ultrasonic excitation has not been routinely used in nondestructive testing of polymers and composites. It is believed that, by combining this stimulation technique with high-sensitive laser vibrometry, it would be possible to ensure acceptable quality of inspection avoiding any external influence on materials to be tested. This study is devoted to analyzing an ultrasonic inspection system including a non-contact magnetostrictive transducer and sa canning laser dopler vibrometer in application to nondestructive testing of polymeric and composite materials. The use of the magnetostrictor has ensured stimulation power high enough to detect hidden defects, provided that the experimental procedure has been appropriately optimized. The radiation pattern of the magnetostrictive device has been analyzed to demonstrate peculiarities of combining such type of ultrasonic emitters with a titanium waveguide.

Quality Inspection of Flip Chip Solder Bumps Using Integrated Analytical, Numerical, and Experimental Modal Analyses

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Jin Yang ◽  
I. Charles Ume
Keyword(s):  
Modal Analysis ◽  
Manufacturing Industry ◽  
Flip Chip ◽  
Solder Bump ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Inspection System ◽  
Solder Bumps ◽  
Out Of Plane ◽  
Plane Displacement

Solder bump inspection of surface mount packages has been a crucial process in the electronics manufacturing industry. A solder bump inspection system has been developed using laser ultrasound and interferometric techniques. In this research, modal analysis is important to correlate the defects with dynamic responses of packaged electronic devices under pulsed laser loading. The effect of solder bump defects on the mode frequencies and mode shapes is reported in this paper. The objective is to develop a modal analysis approach, which integrates analytical, numerical, and experimental methods. In particular, this paper discusses the analytical modeling, numerical modeling, and transient out-of-plane displacement measurements for a 6.35×6.35×0.6mm3 PB18 flip chip mounted on a FR4 board.

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