Vibration Analysis Based Modeling and Defect Recognition for Flip Chip Solder Joint Inspection

2000 ◽  
Author(s):  
Sheng Liu ◽  
Dathan Erdahl ◽  
I. Charles Ume
Keyword(s):  
Solder Joint ◽  
Vibration Analysis ◽  
Flip Chip ◽  
Process Development ◽  
Great Promise ◽  
Quality Inspection ◽  
Vibration Frequencies ◽  
Vibration Responses ◽  
Solder Joint Inspection ◽  
Joint Quality

Abstract A novel approach for flip chip solder joint quality inspection based on vibration analysis is presented. Traditional solder joint inspection methods have their limitations when applied to flip chip solder joint quality inspection. The vibration detection method is a new approach which has advantages such as being non-contact, non-destructive, fast and can be used on-line or during process development. In this technique, a flip chip was modeled as a thick plate supported by solder bumps. Changes in solder joint quality produce different vibration responses of flip chip, and change its natural vibration frequencies. In this paper, the vibration frequencies of a flip chip on a ceramic substrate were calculated using the finite element method. Based on vibration analysis, a laser ultrasound and interferometric system was developed for flip chip solder joint quality inspection. In this system, chips with good solder joints can be distinguished from chips with bad joints using their vibration responses and frequencies. Defects recognition methods were developed and tested. Results indicate this approach offers great promise for solder bump inspection in flip chip, BGA and chip scale packages.

Vibration Analysis Based Modeling and Defect Recognition for Flip-Chip Solder-Joint Inspection

2002 ◽  
Vol 124 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Sheng Liu ◽  
I. Charles Ume
Keyword(s):  
Solder Joint ◽  
Vibration Analysis ◽  
Flip Chip ◽  
Great Promise ◽  
Quality Inspection ◽  
Vibration Frequencies ◽  
Vibration Responses ◽  
Solder Joint Inspection ◽  
Defect Recognition ◽  
Joint Quality

A novel approach for flip-chip solder joint quality inspection based on vibration analysis is presented. Traditional solder joint inspection methods have their limitations when applied to flip chips. The vibration detection method is a new approach which has advantages such as being non-contact, non-destructive, accurate, fast and applicable for in-line inspection or during process development. In this technique, a flip chip was modeled as a thick plate supported by solder bumps. Changes in solder joint quality produce different flip chip vibration responses, and also change its natural vibration frequencies. In this paper, the vibration frequencies of a flip chip on a ceramic substrate were calculated using the finite element method. Based on vibration analysis, a laser ultrasound and interferometric system was developed for flip chip solder joint quality inspection. In this system, chips with good solder joints can be distinguished from chips with bad joints using their vibration responses and frequencies. Data analysis and defect recognition methods were developed and tested. Results indicate this approach offers great promise for solder bump inspection in flip chip, BGA, and chip scale packages.

A novel approach for flip chip solder joint inspection based on pulsed phase thermography

2011 ◽  
Vol 44 (6) ◽  
pp. 484-489 ◽  
Author(s):  
Xiangning Lu ◽  
Guanglan Liao ◽  
Zheyu Zha ◽  
Qi Xia ◽  
Tielin Shi
Keyword(s):  
Solder Joint ◽  
Flip Chip ◽  
Novel Approach ◽  
Pulsed Phase Thermography ◽  
Solder Joint Inspection

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.

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