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Thermomechanical Stress of Lead Free Solder Joint
Libich, Jiří ; Šandera, Josef (referee) ; Starý, Jiří (advisor)
This diploma thesis deals with the reliability of lead-free solder joints at a different interconnection structures. The first goal is to design the test cases shape BGA (FC) for testing the strength of lead-free solder joints at shear test in link with design of measuring method to detection shear strength during isothermal aging of lead-free solder joints. Following this shear stressing is investigating influence material and process compatibility, ie. pads finishing, material of solder and integrate of temperature (this mean thermal energy supplied during soldering) to lead-free solder joint strength.
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Influence of Inert Atmosphere on Surface Wetting in Lead Free Soldering
Nestrojil, Michal ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This master´s thesis dealing with study of influence of inert atmosphere on the wettability of soldered surfaces. The theoretical part is discussed the issue of the soldering, solder joint, oxidation, and inert atmosphere. The glass cover with internal inert gas preheating for the wetting balance testing was prepared in the practical part. With this adjustment were realised tests, in which was examined the effect of the inert gases on the wettability of different materials combination. Further experiments were focused on plasma surface cleaning as possible flux substitution. The evaluation of these experiments were discussed in the end of this master´s thesis. Some of topics were designed for further experiments.
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Reliability of lead free solder joint
Paško, Martin ; Knotek, Tomáš (referee) ; Stejskal, Petr (advisor)
This thesis deals with voids formation in lead-free soldered joint. In theoretical part are described types of voids, voids formation, effect on join reliability, effect reflow profile on voids formation and effect of surface finish on voids formation. In practical part is investigated a effect of thermal stress on voids growth.
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Lead Free Solder Joint Strength and Cooling Gradiient Influence
Vítek, Jiří ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The object of this work is to monitor the impact of gradient cooling on the strength of the solder joint and its crystalic structure. Dummy packages BGA4 were soldered on PCBs with test structure. Base material FR4, Cu interconnections were protected with OSP and Ni – Au surface finishes and SAC405 solder was used. The samples were made in three different cooling gradients, 6.80 °C/s, 2.00 °C/s and 0.16 °C/s. The bond strength was measured by using the shear strength test on device DAGE PC 2400. Realised microsections were studied on an optical microscope OLYMPUS GX 51.
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Lead Free Solder Joint - Models for Reliability Prediction
Nestrojil, Michal ; Šandera, Josef (referee) ; Starý, Jiří (advisor)
This bachelor's thesis deals with reliability prediction of lead-free solder joint. Background research of fatigue models for lead free solder joint.is described in theoretic part Basic terminology and lead free soldering technology operations are mentioned in the theoretical part too. The practical part is dealing with observation of resistivity and solder joint strength during thermal cycling. Evaluation of results and experiments and posibility for future application of these results for fatigue model realisation is discussed in the end of this bachelor's thesis
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Lead Free Solder Joint Strength and Cooling Gradiient Influence
Vítek, Jiří ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The object of this work is to monitor the impact of gradient cooling on the strength of the solder joint and its crystalic structure. Dummy packages BGA4 were soldered on PCBs with test structure. Base material FR4, Cu interconnections were protected with OSP and Ni – Au surface finishes and SAC405 solder was used. The samples were made in three different cooling gradients, 6.80 °C/s, 2.00 °C/s and 0.16 °C/s. The bond strength was measured by using the shear strength test on device DAGE PC 2400. Realised microsections were studied on an optical microscope OLYMPUS GX 51.
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Lead Free Solder Joint - Models for Reliability Prediction
Nestrojil, Michal ; Šandera, Josef (referee) ; Starý, Jiří (advisor)
This bachelor's thesis deals with reliability prediction of lead-free solder joint. Background research of fatigue models for lead free solder joint.is described in theoretic part Basic terminology and lead free soldering technology operations are mentioned in the theoretical part too. The practical part is dealing with observation of resistivity and solder joint strength during thermal cycling. Evaluation of results and experiments and posibility for future application of these results for fatigue model realisation is discussed in the end of this bachelor's thesis
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|
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Reliability of lead free solder joint
Paško, Martin ; Knotek, Tomáš (referee) ; Stejskal, Petr (advisor)
This thesis deals with voids formation in lead-free soldered joint. In theoretical part are described types of voids, voids formation, effect on join reliability, effect reflow profile on voids formation and effect of surface finish on voids formation. In practical part is investigated a effect of thermal stress on voids growth.
|
|
|
Influence of Inert Atmosphere on Surface Wetting in Lead Free Soldering
Nestrojil, Michal ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This master´s thesis dealing with study of influence of inert atmosphere on the wettability of soldered surfaces. The theoretical part is discussed the issue of the soldering, solder joint, oxidation, and inert atmosphere. The glass cover with internal inert gas preheating for the wetting balance testing was prepared in the practical part. With this adjustment were realised tests, in which was examined the effect of the inert gases on the wettability of different materials combination. Further experiments were focused on plasma surface cleaning as possible flux substitution. The evaluation of these experiments were discussed in the end of this master´s thesis. Some of topics were designed for further experiments.
|
|
|
Thermomechanical Stress of Lead Free Solder Joint
Libich, Jiří ; Šandera, Josef (referee) ; Starý, Jiří (advisor)
This diploma thesis deals with the reliability of lead-free solder joints at a different interconnection structures. The first goal is to design the test cases shape BGA (FC) for testing the strength of lead-free solder joints at shear test in link with design of measuring method to detection shear strength during isothermal aging of lead-free solder joints. Following this shear stressing is investigating influence material and process compatibility, ie. pads finishing, material of solder and integrate of temperature (this mean thermal energy supplied during soldering) to lead-free solder joint strength.
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