Reliability Improvement of Solder Joints Between Ceramic Chip Resistors and Insulated Metal Substrates With Thick Copper Pads

2005 ◽  
Author(s):  
Kenji Monden
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Epoxy Resin ◽  
Base Plate ◽  
Temperature Cycling ◽  
High Thermal Conductivity ◽  
Metal Base ◽  
Insulating Layer ◽  
Cycling Test ◽  
Temperature Cycling Test

An insulated metal substrate (IMS) is a circuit board comprised of an insulating layer on a metal base plate. The insulating layer is made from epoxy resin incorporating dense inorganic fillers with high thermal conductivity. Because the substrates have high thermal conductivity, they have been used in electrical products that generate intense heat, such as inverters, amplifiers, motor drivers and so on. For using a high power semiconductor, thick copper pads are used on IMSs. In many times, aluminum plates are used for metal base plates in IMSs. The substrates are repeated heating and cooling in ordinary usage. So cracks of solder joints between ceramic chip resistors and IMSs often occur because of coefficient of thermal expansion (CTE) mismatch between ceramic and aluminum. Moreover, SnAgCu solder used to replace eutectic Sn/Pb solder as the joint has become major trend from a viewpoint of earth environmental protection. Finite element analysis was used for development of a high reliable IMS to meet these demand for the IMSs. The accelerated temperature cycling test on IMS was simulated by finite element method. The influence of the CTE of metal base plate and the influence of the modulus of insulating layer were studied. The reliability of solder was predicted to increase with CTE reduction of metal base plate. The modulus of insulating layer must be reduced sharply for a high reliable IMS. However, the insulating layer is difficult to be realized by using the epoxy resin. So the effect by fixing the chip resistor on a IMS using resin was calculated. When the space between the bottom of a chip resistor and the copper pads were filled up with resin such as underfill resin in ball grid array (BGA) mounting, it was predicted that the stress of solder decreased. The effect was confirmed by experiment. Solder joint fracture life of accelerated temperature cycling test on IMS was improved more than three times longer by using the underfill resin.

Effect of Percolation on Equivalent Thermal Conductivity of Insulating Layer in Insulated Metal Substrates

2003 ◽  
Author(s):  
Kenji Monden
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Volume Fraction ◽  
High Thermal Conductivity ◽  
Inorganic Filler ◽  
Interfacial Region ◽  
Equivalent Thermal Conductivity ◽  
Metal Base ◽  
Predictive Values ◽  
Insulating Layer

An insulated metal substrate (IMS) is a circuit board comprising an insulating layer on a metal base plate. The insulating layer is made from epoxy resin incorporating dense inorganic fillers with high thermal conductivity. Because the substrates have high thermal conductivity, they are used in applications where electric parts generate intense heat, such as inverters, amplifiers, motor drivers and so on. It is expected that the insulating layer has higher thermal conductivity as the use of an IMS is expanded. Therefore, the influence of percolation on the equivalent thermal conductivity of an insulating layer is considered. The effect of the volume fraction of inorganic filler on the equivalent thermal conductivity of insulating layer in IMS is experimentally investigated. The equivalent thermal conductivity of insulating layer as a function of volume fraction of filler is estimated by FEM and Monte Carlo technique together. The acquired value of percolation threshold volume fraction is the same grade as the previous reported value. Based on these experimental and numerical results, an effective thermal conductivity of a filler which contains surrounding interfacial region is evaluated. The effective thermal conductivity of an irregular filler is presumed smaller than that of a spherical filler. It is noted that the control of filler size and shape is important for the formation of high thermal conductivity of an insulating layer. In addition, an improved equation for the equivalent thermal conductivity of insulating layer in IMS is proposed. The predictive values from the equation for insulating layer in an improved IMS agree with experimental results.

Equivalent Thermal Conductivity of Insulating Layer in Insulated Metal Substrates

2006 ◽  
Vol 45 ◽  
pp. 2664-2669 ◽  
Author(s):  
Kenji Monden
Keyword(s):  
Thermal Conductivity ◽  
Volume Fraction ◽  
Base Plate ◽  
Circuit Board ◽  
Equivalent Thermal Conductivity ◽  
Metal Base ◽  
Predictive Values ◽  
Insulating Layer ◽  
Ceramic Fillers ◽  
Intense Heat

An insulated metal substrate (IMS) is a circuit board comprising an insulating layer on a metal base plate. The insulating layer is made from epoxy resin incorporating dense ceramic fillers. The substrates are used in applications where electric parts generate intense heat. It is expected that the insulating layer has higher thermal conductivity as the use of an IMS is expanded. Therefore, the influence of percolation on the equivalent thermal conductivity (ETC) of an insulating layer is considered. The Effect of the volume fraction of ceramic filler on the ETC of insulating layer in IMS is investigated. The ETC as a function of volume fraction of filler is estimated. Based on these experimental and numerical results, an ETC of a filler is evaluated. The ETC of an irregular filler is presumed smaller than that of a spherical filler. It is thought that the control of filler size and shape is important for the formation of high thermal conductivity of an insulating layer. In addition, an improved equation for the ETC of IMS is proposed. The predictive values from the equation for an improved IMS agree with experimental results.

Temperature Characteristics of Li-Ion Batteries

2014 ◽  
Vol 1008-1009 ◽  
pp. 274-276
Author(s):  
Hong Wei Wang ◽  
Zi Qiang Tao ◽  
Yan Ling Fu ◽  
Hong Bai ◽  
Hai Qing Xiao
Keyword(s):  
Temperature Cycling ◽  
Safety Performance ◽  
Quality And Safety ◽  
Li Ion Batteries ◽  
Temperature Characteristics ◽  
Cycling Test ◽  
Li Ion ◽  
Temperature Cycling Test

Two kinds of import laptop battery and one kind of domestic laptop battery were investigated in the temperature cycling test. The results showed that all the samples didn’t fire, explosion and leakage in the temperature cycling tests. But the shell glue of domestic laptop battery was disabled more serious then that of import laptop battery and it still exist some security risk.Therefore, There is a long way to go to investigate and improve the quality and safety performance of some laptop battery.

scholarly journals A novel h-BN–RGO hybrids for epoxy resin composites achieving enhanced high thermal conductivity and energy density

RSC Advances ◽  
2017 ◽  
Vol 7 (38) ◽  
pp. 23355-23362 ◽  
Author(s):  
Tao Huang ◽  
Xiaoliang Zeng ◽  
Yimin Yao ◽  
Rong Sun ◽  
Fanling Meng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Energy Density ◽  
Epoxy Resin ◽  
High Thermal Conductivity ◽  
Resin Composites ◽  
Epoxy Resin Composites ◽  
Significant Attention

In recent decades, significant attention has been focused on developing composite materials with high thermal conductivity utilizing h-BN, which has outstanding thermal conductivity.

Fiber alignment shift in temperature cycling test

1998 ◽  
Author(s):  
Yih-Cheng Sheu ◽  
Cheng-Huang Chen ◽  
Chy-Pen Chien ◽  
Jao-Hwa Kuang ◽  
Wood-Hi Cheng ◽  
...  
Keyword(s):  
Temperature Cycling ◽  
Fiber Alignment ◽  
Cycling Test ◽  
Temperature Cycling Test

Can Power Cycling Life of Solder Joint Interconnections be Assessed on the Basis of Temperature Cycling Tests?

1989 ◽  
Vol 111 (4) ◽  
pp. 310-312 ◽  
Author(s):  
E. Suhir
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Temperature Cycling ◽  
Cycling Test ◽  
Test Conditions ◽  
Power Cycling ◽  
Temperature Cycling Test ◽  
Cycling Life

We discuss how temperature cycling test conditions could be modified to be used for a tentative evaluation of the fatigue life of solder joint interconnections in surface mounted devices subjected to power cycling.

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