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Temperature Profiles Measurement of SMD Packages
Strapko, Jaroslav ; Szendiuch, Ivan (referee) ; Starý, Jiří (advisor)
Diploma thesis mainly deals with temperature management and calculation of temperature profile in oven by using SMD packages (PLCC, 1206) of different thermal capacitance on testing PCB. Above all shows theoretical consecution of temperature profile calculation in oven by using known mathematical method like the lumped capacitance method or finite difference method. Theoretical solution and measured values are compared. Diploma thesis also deals with fixation methods of thermocouples K type on assembly, comparison methods based on known and subexperiment, determines the deficiencies of methods. This thesis can perform as theoretical as well as experimental resource to prediction of temperature profiles of PCB´s with different assembly density.
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Wave Soldering Fluxes Comparison
Stoklásek, Lukáš ; Martinec, Petr (referee) ; Starý, Jiří (advisor)
Semestral thesis introduces the problematics of wave soldering fluxes, flux residues and problems of electromigration. Practical part describes measuring of ionic contamination by using conductometric method, measuring the wettability by the wetting balance method and amount of failures on wave soldered printed circuit boards with these fluxes. The main object is to compare quality of the fluxes.
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Temperature Profiles Measurement of BGA Packages in Reflow Soldering
Tomčáková, Anna ; Bureš, Tomáš (referee) ; Starý, Jiří (advisor)
This graduation thesis addresses questions to thermal profile measurement of PBGA package during solder reflow process. The first part of thesis deals with problem of reflow process and reliability factors of solder joint connection. Next part analyses operation principles of thermocouples that are commonly used for temperature measurement. The experimental part deals with methods of thermocouples fixation during tests and measurements of dummy PBGA package. There was realized a method of dummy PBGA thermal profiles measurement and sample testing with and without simulated thermal load on PBGA package. The end of thesis concerns on possibilities of thermal profiles evaluation by using PWI method and thermal profile optimization of reflow process.
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Logistics and supply of PCB for repair of notebooks
Grob, Filip ; Starý, Jiří (referee) ; Špinka, Jiří (advisor)
This diploma thesis deals with issues of inventory management and logistics controlling. These segments are one of most important instruments used in logistics. Theory of these logistic instrumens are used as a base for practical part of this diploma thesis, where is described and suggested methodology for inventory management of printed circuit board in repair center. This buffer inventory serves for securing performance of customer’s supplies in case of failure on repair line. Thereinafter is realized program in MS Excel interface for supplying leadership with main insistence to prevent order delay.
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Production of Multilayer PCB
Janda, Ondřej ; Zatloukal, Miroslav (referee) ; Starý, Jiří (advisor)
This master thesis introduces the problematics of multilayer printed circuit boards. Theoretical part is focused on materials used for production of multilayer PCB and their parameters. At the same time, it focuses on the pressing process of multi-layered PCB, the types of presses used and their advantages and disadvantages. Practical part describes the methodology and testing of the PCB to identify the reliability of chosen electrical parameters. Testing is aimed to simulate thermal stress during machine soldering and during thermal stress in the target environment.
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PCBs Repairs with BGA and FC Packages
Buřival, Tomáš ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
Graduation thesis is specialized on dilemma of the integrated circuits with ball grid array. Chapter two describes several types of packages and confrontation of their characteristics. Chapter three considers possibilities of corrections these boards bedded with packages, mounting and demounting of these packages, method of camera control and also inspection of the soldering process. Chapter four attend to practical measuring of thermal profiles and their optimalization.
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Quality of PCB Surface Finishes and Test Coupon Optimization
Minář, Jan ; Přikryl, Tomáš (referee) ; Starý, Jiří (advisor)
This master’s thesis deals with measuring and evaluation of wetting for samples of different surface finishes, using a test coupon developed in cooperation with firm Gatema. It deals with surface finishes ENIG and immersion tin. For these samples deals with quality monitoring and periodic testing of these surface finishes. The solder using for tests is SAC305. Test methods are used for simulation of reflow soldering and wave soldering.
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QFN Packages Soldering and Technology Procedures
Jakub, Miroslav ; Brno, Petr Martinec, HONEYWELL (referee) ; Starý, Jiří (advisor)
This master´s thesis deals with QFN packages soldering and technology procedures optimization. The aim of theoretical part is description of QFN packages, their assembly and reflow soldering on PCB in HONEYWELL. The aim of the practical part is to propose a method of measuring temperature and optimizing the thermal profiles of selected PCB with QFN packages by using convection (HONEYWELL) and infrared (BUT) reflow ovens. Comparison and evaluation of thermal profiles for 3 production PCBś with QFN packages using solder paste AIM NC257-2 were realised. The main part of master´s thesis are appearance evaluation of solder joints, preparing microsection and measuring intermetallic layers thickness by using the optical and the scanning electron microscopes, analysation and study of QFN defects created during soldering proces. These tests were performed with 2 production PCB´s. Optimization of SPI and soldering technology procedures where were analyzed QFN packages were processed on one type of PCB. Interesting part of this diplomma thesis is creating of the 3D heat transfer model of QFN package during the reflow soldering in SolidWorks.
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Solder Joint Quality based on Heating Factor
Kučírek, Martin ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
Master’s thesis in the theoretical part analyses the heating factor (Q), which has significant share on quality of a solder joint. The practical part describes the design and production of test PCB and setting temperature profiles, SMD resistors soldering by using BiSn solder paste. Shear tests of SMD solder joints were realised and evaluated including isothermal ageing samples. At the end of master’s thesis solder joints visual aspects and defects were evaluated, measurement thickness of intermetallic compound by not only optical microscope but also SEM, discussion about results and Q was evaluated.
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