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SMD Rework station
Szabó, Michal ; Roubal, Zdeněk (referee) ; Szabó, Zoltán (advisor)
This thesis describes the theory of solder joint and conditions under which it is formed correctly. Further, methods of hand soldering are discussed, and possibilities of temperature regulation of soldering tip are analyzed. Methods of creating a soldering station and its key features are depicted. In practical part, the solution of how to create a soldering station with soldering iron, desolder gun and heatgun is given and is constructed. While testing a defect is found that prevents the power portion of soldering station to function properly and prevents completion.
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Modification of PCB cleaning process after removing BGA component
Procházka, Adam ; Bžoněk, Tomáš (referee) ; Řezníček, Michal (advisor)
This bachelor thesis deals with the modification of DPS cleaning process after the removal of BGA components. The thesis is divided into five main parts including the introduction and conclusion. The introduction comprises an assignment and aim of the thesis. The first, theoretical, part then deals with different kinds of soldering, individual types of solders and the rework process itself. The second part examines the whole practical part in detail, from the proposal of the test printed circuit board to its mounting, soldering and subsequent testing. Also, it explains the practical tests for connectors. The third part then describes the board testing by thermal cycling. The last part consists of the summary of results, a comparison of individual soldering pastes and conclusion.
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The Analysis of Solder Preforms in Surface Mount Assembly
Novotný, Václav ; Vala, Radek
This article is focused on the sphere of solder joints reliability in technology of surface mount assembly and the issue of manufactory of solder joints with solder preforms is introduced closer. It also describes types of solder preforms, their application and different methods of using in surface mount assembly. Text further comprises comparison of the solder joint which is manufactured by printing of solder paste through the cooper stencil and solder joint manufactured by applying of solder preform. The results of these basic processes are compared with method of solder fortification. In conclusion, there are evaluated outputs from experimental manufactory of solder joints with solder preforms and complemented by outputs which are achieved by x-ray machine.
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Streamlining the Process of Cleaning PCB after Removing BGA
Starčok, Tomáš
This paper deals with issues connected with solder residues cleaning process of modern BGA packages. First part is focused on contact cleaning method of solder residues. It describes main disadvantages and incurred defects of this method. Second part is focused on a new contactless cleaning method with special tool and then suggests variety of verification possibilities.
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STRUCTURAL, THERMODYNAMICS AND PHYSICAL PROPERTIES OF Zn Sn Al ALLOYS
Drápala, J. ; Musiol, J. ; Petlák, D. ; Vodárek, V. ; Smetana, B. ; Zlá, S. ; Kostiuková, G. ; Kroupa, Aleš ; Sidorov, V.E.
Some results of thermodynamic, structural and physical properties of Al-Sn-Zn alloys are presented in our paper. The ternary Al-Sn-Zn alloys were prepared in a resistance furnace in evacuated ampoules. The alloys were studied metallographically, their micro-hardness and X-ray micro-analysis (EDX, SEM) of individual phases were measured. Temperatures of phase transitions (liquidus, solidus, invariant reactions, etc.) were obtained using the DTA method (Setaram SETSYS 18 (TM)). The long time annealing (250, 300, 350 degrees C, 3, 7, 14 or 28 days) was used in order to achieve the thermodynamic equilibrium. The results were confronted with thermodynamic modelling of the ternary Al Sn Zn system in the Institute of Physics of Materials AS of the Czech Republic in Brno. We have studied density (by gamma-absorption method), electrical resistivity (by contactless method in rotating magnetic field) and magnetic susceptibility (by Faraday's method) of some Al-Sn-Zn alloys containing up to 10 at.% of aluminum and up to 65 at.% of zinc. The increasing of zinc content resulted in the decrease of the density and susceptibility values, except for one sample. The resistivity values practically didn't depend on the zinc content in the crystalline state, whereas a maximum was found for one of the samples in the liquid state. This work has been made in the frame of COST Action MP0602 project 'Advanced Solder Materials for High-Temperature Application'.
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Optimization of surface treatment of stainless steels
Mačátová, Lucie ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The project deals with the processes of degreasing industry and testing new laser cleaning process, which has been experimentally verified and tested in the production process. Project also deals with soldering in general as a technology of joining metals. Included are the main components of the soldering, such as solder, flux, the types of connections and their use, ways of soldering and last but not least the soldering corrosion-resistant steel.
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Optimization of surface treatment of stainless steels
Mačátová, Lucie ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The project deals with the processes of degreasing industry and testing new laser cleaning process, which has been experimentally verified and tested in the production process. Project also deals with soldering in general as a technology of joining metals. Included are the main components of the soldering, such as solder, flux, the types of connections and their use, ways of soldering and last but not least the soldering corrosion-resistant steel.
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Lead-Free Voids Cause Mechanisms and Influence on Reliability
Šimon, Vojtěch ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The aim of this work is to analyze reliability of lead-free solder join, in particular the voids generated during the soldering process. The main target of the theoretical part of the work is to isolate basic mechanisms of formation of the voids and optimize the soldering process. The practical part of the paper is based on monitoring the count and size of the voids in a solder join. An X-Ray tomograph has been chosen as a non-destructive method of detection. The statistical part of this work compares conventional soldering of the entire board with local soldering by IR radiation.
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