Experimental Study of Solder Joint Reliability for External Heat Sink Installation on FCBGA

Author(s):  
Nicholas Kao ◽  
Jeng Yuan Lai ◽  
Yu Po Wang ◽  
C. S. Hsiao

As the increasing power consumption for electronic devices, thermal management on board level becomes a challenge to manufacturers who are integrating more functionality and components into a board in order to the high performance products in this competitive market. To drive such high level products requires more power consumption and consequently arises a thermal risk of system malfunction because of overheating to chips. A common implement for thermal solution is a heat sink installed on package via clip mechanism that maintained a compressive force to clamp the heat sink and board to fulfill this thermal dissipation demand. But this compressive force along with operation temperature will arise solder joint risk and potentially induce the function failed due to the clamped force may potentially arise solder ball creep after long operating time and damage the connection failed of solder ball and PCB. This paper describes the experimental setup and test results to evaluate the solder joints creep behavior in the presence of clamped force and operation temperature. An External Heat Spreader Flip Chip BGA (EHS-FCBGA) was tested for several weeks under 85°C with a compressive force. The different levels of uniform compressive forces were applied with 25kg and 50kg metal blocks on EHS-FCBGA to simulate the clamped force. All test vehicles were placed in an oven at 85°C for several weeks to accelerate thermal aging condition and measured solder ball collapsed shapes and do open-short test at the end of every two weeks.

2008 ◽  
Vol 5 (4) ◽  
pp. 180-187
Author(s):  
Sang Ha Kim ◽  
Chika Kakegawa ◽  
Hiroshi Tabuchi ◽  
Han Park

The major concerns posed by system-in-package (SiP) designs for network applications are the interconnection reliability between the memory plastic ball grid array (PBGA) package and the SiP module, which we refer to as 2nd-level interconnection, and between the SiP module and the system board, which we refer to as 3rd-level interconnection, induced by thermomechanical stress to the large SiP module, i.e., 55 × 55 mm2 package body size. In this paper, finite element analysis (FEA) and design of experiment (DOE) case studies were used to evaluate the 2803-pin flip chip SiP (FCSiP) and to determine the best construction of the SiP module and optimize the assembly material set. Heat spreader (lid) thickness, heat spreader material, and under-fill implementation were considered in the stress and fatigue lifetime FEA case studies and long-term solder joint reliability, which was accelerated thermal cycle (ATC) tested at operating temperatures from 0 to 100°C. Another important factor in the system-level reliability is an external heat sink, and its compressive force effect was also investigated in the ATC test. In addition, short-term mechanical reliability tests, such as the 4-point monotonic bend test based on the IPC-9702 specification and mechanical shock test based on the JESD22-B110A standard, were also evaluated for the 2803-pin FCSiP qualification. Finally, the results of these experiments were compared with the FEA data in a correlation process.


2007 ◽  
Vol 4 (4) ◽  
pp. 186-194 ◽  
Author(s):  
C.I. Chen ◽  
S.C. Wu ◽  
D.S. Liu ◽  
C.Y. Ni ◽  
T. D. Yuan

Due to the high speed and high I/O count requirements for semiconductor packages, thousands of soldered interconnections are indispensable, and this situation renders traditional finite element method (FEM) analysis a formidable challenge. This paper presents a 3D-equivalent global model and local submodeling technique to investigate board-level solder joint reliability under cyclic temperature loading. The equivalent global model is capable of addressing critical solder failure locations. An individual local solder ball is used to predict the number of cycles to failure. The high performance flip-chip ball grid array (HFCBGA) package case was studied with the provided experimental data. According to FEM results, the predicted solder ball life is close to that observed experimentally. Therefore, the global-to-local modeling technique can be concluded to provide an efficient methodology for evaluating very high pin count HFCBGA package reliability.


2020 ◽  
pp. 57-62
Author(s):  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova

This work contains analysis of characteristics of automobile lamps by Philips, KOITO, ETI flip chip LEDs, Osram, General Electric (GE), Gtinthebox, OSLAMPledbulbs with H1, H4, H7, H11 caps: luminous flux, luminous efficacy, correlated colour temperature. Characteristics of the studied samples are analysed before the operation of the lamps. The analysis of the calculation results allows us to make a conclusion that the values of correlated colour temperature of halogen lamps are close to the parameters declared by manufacturers. The analysis of the study results has shown that, based on actual values of correlated colour temperature, it is not advisable to use LED lamps in unfavourable weather conditions (such as rain, fog, snow). The results of the study demonstrate that there is a slight dispersion of actual values of luminous flux of halogen lamps by different manufacturers. Maximum variation between values of luminous flux of different lamps does not exceed 14 %. The analysis of the measurement results has shown that actual values of luminous flux of all halogen lamps comply with the mandatory rules specified in the UN/ECE Regulation No. 37 and luminous flux of LED lamps exceeds maximum allowable value by more than 8 %. Luminous efficacy of LED lamps is higher than that of halogen lamps: more than 82 lm/W and lower power consumption. The results of the measurements have shown that power consumption of a LED automobile lamp is lower than that of similar halogen lamps by 3 times and their luminous efficacy is higher by 5 times.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 555
Author(s):  
Sangkyung Na ◽  
Sanghun Song ◽  
Seunghyuk Lee ◽  
Jehwan Lee ◽  
Hyun Kim ◽  
...  

In this study, evaporator optimization, via both experimental and simulation methods was conducted. To evaluate the evaporator performance, under the optimal system, the compressor operating time and the effects of oil on the refrigerator system were studied. If the temperature of the refrigerator chamber reaches the setting value, the compressor stops working and it leads to the temperature of the refrigerator chamber slowly increasing, due to the heat transfer to the ambient. When the refrigerator temperature is out of the setting range, the compressor works again, and the refrigerator repeats this process until the end of its life. These on/off period can be controlled through the compressor piston movement. To determine the optimal compressor operating conditions, experiments of monthly power consumption were conducted under various compressor working times and the lowest power consumption conditions was determined when the compressor worked continuously. Lubricating oil, the refrigerator system, using oil, also influenced the system performance. To evaluate the effect of oil, oil eliminated and oil systems were compared based on cooling capacity and power consumption. The cooling capacity of the oil eliminated system was 2.6% higher and the power consumption was 3.6% lower than that of the oil system. After determining the optimal operating conditions of the refrigerator system, visualization experiments and simulations were conducted to decide the optimal evaporator and the conventional evaporator size can be reduced by approximately 2.9%.


2014 ◽  
Vol 54 (5) ◽  
pp. 939-944 ◽  
Author(s):  
Ye Tian ◽  
Xi Liu ◽  
Justin Chow ◽  
Yi Ping Wu ◽  
Suresh K. Sitaraman

2021 ◽  
Author(s):  
Anthony A. DiCarlo ◽  
Rickey A. Caldwell

Abstract This work aims to determine the optimal heat sink fin shape to promote the efficient rise of hot air away from the heat sink. The heat transfer and convective flow dynamics external to a commercial Stirling engine are investigated. In particular, this study employs an adjoint optimization approach based on CFD simulations to determine the sensitivity of the objective function to the shape of the heat sink and influence on the natural convection heat flow away from the external heat sink. This deterministic optimization approach increases the heat transfer rate of the heat sink by nearly 20% in this study when performing a small number of design iterations.


Author(s):  
Jin Cui ◽  
Liang Pan ◽  
Justin A. Weibel

Abstract Pluggable optoelectronic transceiver modules are widely used in the fiber-optic communication infrastructure. It is essential to mitigate thermal contact resistance between the high-power optical module and its riding heat sink in order to maintain the required operation temperature. The pluggable nature of the modules requires dry contact thermal interfaces that permit repeated insertion–disconnect cycles under low compression pressures (∼10–100 kPa). Conventional wet thermal interface materials (TIM), such as greases, or those that require high compression pressures, are not suitable for pluggable operation. Here we demonstrate the use of compliant micro-structured TIM to enhance the thermal contact conductance between an optical module and its riding heat sink under a low compression pressure (20 kPa). The metallized and polymer-coated structures are able to accommodate the surface nonflatness and microscale roughness of the mating surface while maintaining a high effective thermal conductance across the thickness. This dry contact TIM is demonstrated to maintain reliable thermal performance after 100 plug-in and plug-out cycles while under compression.


2006 ◽  
Vol 504 (1-2) ◽  
pp. 426-430 ◽  
Author(s):  
Dae-Gon Kim ◽  
Jong-Woong Kim ◽  
Seung-Boo Jung

2000 ◽  
Author(s):  
Sheng Liu ◽  
Dathan Erdahl ◽  
I. Charles Ume

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.


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