Efficient Inspection Algorithm for IC Solder Joints Based on Feature Statistical Analysis

2013 ◽  
Vol 365-366 ◽  
pp. 688-691
Author(s):  
Hong Wei Xie ◽  
Kun Zhang
Keyword(s):  
Statistical Analysis ◽  
Solder Joint ◽  
Defect Detection ◽  
Expectation Maximization ◽  
Solder Joints ◽  
Test Stage ◽  
Training Stage ◽  
Defect Diagnosis ◽  
Solder Joint Inspection

An efficient feature statistical analysis based inspection algorithm for IC solder joint inspection is proposed. The defect detection is divided into training stage and test stage. In the training stage, three simple but efficient features are extracted and trained with Greedy Expectation-Maximization method. In the test stage, sub-regions are tested using the critical features. The defect diagnosis rules are defined to determine the specific defect types. To evaluate the performance of the proposed method, experiment was performed, and the inspection results have verified the effectiveness of proposed method.

An Efficient Method for Solder Joint Inspection Based on Statistical Learning

2011 ◽  
Vol 121-126 ◽  
pp. 4931-4935
Author(s):  
Yong Cong Kuang ◽  
Gao Fei Ouyang ◽  
Hong Wei Xie ◽  
Xian Min Zhang
Keyword(s):  
Feature Selection ◽  
Solder Joint ◽  
Statistical Learning ◽  
Efficient Method ◽  
Solder Joints ◽  
Sampling Algorithm ◽  
Inspection Method ◽  
Defect Type ◽  
Imbalance Problem ◽  
Solder Joint Inspection

To improve the performance of current solder joint inspection method, an efficient method based on statistical learning is proposed in this paper. In the method, the solder was divided into several sub-regions to determine the defect type. To resolve imbalance problem, an improved over-sampling algorithm was proposed in which the synthetics samples are generated between the boundary samples and their neighbors. AdaBoost was used for feature selection and classification for every sub-region. Experiments results showed that the defects of solder joints can be identified properly using the proposed algorithm.

IC solder joint inspection based on the Gaussian mixture model

2016 ◽  
Vol 28 (4) ◽  
pp. 207-214 ◽  
Author(s):  
Nian Cai ◽  
Qian Ye ◽  
Gen Liu ◽  
Han Wang ◽  
Zhijing Yang
Keyword(s):  
Solder Joint ◽  
Gaussian Mixture Model ◽  
Mixture Model ◽  
Integrated Circuit ◽  
Printed Circuit Boards ◽  
Solder Joints ◽  
Gaussian Mixture ◽  
Content Type ◽  
Solder Joint Inspection ◽  
Frequency Map

Purpose This paper aims to inspect solder joint defects of integrated circuit (IC) components on printed circuit boards. Here, an IC solder joint inspection algorithm is developed based on a Gaussian mixture model (GMM). Design/methodology/approach First, the authors train a GMM using numerous qualified IC solder joints. Then, the authors compare the IC solder joint images with the trained model to inspect the potential defects. Finally, the authors introduce a frequency map and define a metric termed as normalized defect degree to evaluate qualities of the tested IC solder joints. Findings Experimental results indicate that the proposed method is superior to the state-of-the-art methods on IC solder joint inspection. Originality/value The approach is a promising method for IC solder joint inspection, which is quite different from the traditional classifier-based methods.

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.

scholarly journals Study on the Reliability of Sn–Bi Composite Solder Pastes with Thermosetting Epoxy under Thermal Cycling and Humidity Treatment

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 733
Author(s):  
Lu Liu ◽  
Songbai Xue ◽  
Ruiyang Ni ◽  
Peng Zhang ◽  
Jie Wu
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Composite Solder ◽  
Solder Joints ◽  
Solder Paste ◽  
Epoxy System ◽  
Mechanical Reinforcement ◽  
Microstructure Observation ◽  
Temperature And Humidity ◽  
Thermosetting Epoxy

In this study, a Sn–Bi composite solder paste with thermosetting epoxy (TSEP Sn–Bi) was prepared by mixing Sn–Bi solder powder, flux, and epoxy system. The melting characteristics of the Sn–Bi solder alloy and the curing reaction of the epoxy system were measured by differential scanning calorimeter (DSC). A reflow profile was optimized based on the Sn–Bi reflow profile, and the Organic Solderability Preservative (OSP) Cu pad mounted 0603 chip resistor was chosen to reflow soldering and to prepare samples of the corresponding joint. The high temperature and humidity reliability of the solder joints at 85 °C/85% RH (Relative Humidity) for 1000 h and the thermal cycle reliability of the solder joints from −40 °C to 125 °C for 1000 cycles were investigated. Compared to the Sn–Bi solder joint, the TSEP Sn–Bi solder joints had increased reliability. The microstructure observation shows that the epoxy resin curing process did not affect the transformation of the microstructure. The shear force of the TSEP Sn–Bi solder joints after 1000 cycles of thermal cycling test was 1.23–1.35 times higher than the Sn–Bi solder joint and after 1000 h of temperature and humidity tests was 1.14–1.27 times higher than the Sn–Bi solder joint. The fracture analysis indicated that the cured cover layer could still have a mechanical reinforcement to the TSEP Sn–Bi solder joints after these reliability tests.

Effect of intermetallic compound layer thickness on the shear strength of 1206 chip resistor solder joint

2015 ◽  
Vol 27 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Peter K. Bernasko ◽  
Sabuj Mallik ◽  
G. Takyi
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Layer Thickness ◽  
Solder Joints ◽  
Ageing Time ◽  
Circuit Board ◽  
Intermetallic Compound Layer ◽  
Content Type ◽  
Surface Mount

Purpose – The purpose of this paper is to study the effect of intermetallic compound (IMC) layer thickness on the shear strength of surface-mount component 1206 chip resistor solder joints. Design/methodology/approach – To evaluate the shear strength and IMC thickness of the 1206 chip resistor solder joints, the test vehicles were conventionally reflowed for 480 seconds at a peak temperature of 240°C at different isothermal ageing times of 100, 200 and 300 hours. A cross-sectional study was conducted on the reflowed and aged 1206 chip resistor solder joints. The shear strength of the solder joints aged at 100, 200 and 300 hours was measured using a shear tester (Dage-4000PXY bond tester). Findings – It was found that the growth of IMC layer thickness increases as the ageing time increases at a constant temperature of 175°C, which resulted in a reduction of solder joint strength due to its brittle nature. It was also found that the shear strength of the reflowed 1206 chip resistor solder joint was higher than the aged joints. Moreover, it was revealed that the shear strength of the 1206 resistor solder joints aged at 100, 200 and 300 hours was influenced by the ageing reaction times. The results also indicate that an increase in ageing time and temperature does not have much influence on the formation and growth of Kirkendall voids. Research limitations/implications – A proper correlation between shear strength and fracture mode is required. Practical implications – The IMC thickness can be used to predict the shear strength of the component/printed circuit board pad solder joint. Originality/value – The shear strength of the 1206 chip resistor solder joint is a function of ageing time and temperature (°C). Therefore, it is vital to consider the shear strength of the surface-mount chip component in high-temperature electronics.

scholarly journals Prediction of mechanical properties and fatigue life of nano silver paste in chip interconnection

2020 ◽  
Author(s):  
Hui YANG ◽  
Jihui Wu
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Stress And Strain ◽  
Nano Silver ◽  
Finite Element Software ◽  
Flip Chips ◽  
Empirical Correction ◽  
Prediction Of Mechanical Properties

Abstract The simulation of nano-silver solder joints in flip-chips is performed by the finite element software ANSYS, and the stress-strain distribution results of the solder joints are displayed. In this simulation, the solder joints use Anand viscoplastic constitutive model, which can reasonably simulate the stress and strain of solder joints under thermal cycling load. At the same time this model has been embedded in ANSYS software, so it is more convenient to use. The final simulation results show that the areas where the maximum stresses and strains occur at the solder joints are mostly distributed in the contact areas between the solder joints and the copper pillars and at the solder joints. During the entire thermal cycling load process, the area where the maximum change in stress and strain occurs is always at the solder joint, and when the temperature changes, the temperature at the solder joint changes significantly. Based on comprehensive analysis, the relevant empirical correction calculation equation is used to calculate and predict the thermal fatigue life of nano-silver solder joints. The analysis results provide a reference for the application of nano-silver solder in the electronic packaging industry.

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