Método de desmontagem de placas de circuito impresso provenientes de resíduos de equipamentos eletroeletrônicos para reciclagem
Data
2017-11-15
Autores
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Biblioteca Digital de Teses e Dissertações da USP
Universidade de São Paulo
Escola de Engenharia de São Carlos
Universidade de São Paulo
Escola de Engenharia de São Carlos
Resumo
Descrição
Nesta tese é apresentado um novo método de desmontagem das placas de circuito impresso obsoletas ou defeituosas, provenientes de resíduos de equipamentos eletroeletrônicos, para aplicação no processo de reciclagem. A desmontagem tem por objetivo segregar a PCI para que o material reciclado apresente maior pureza, bem como facilitar as etapas posteriores no processo de reciclagem. A desmontagem proposta é classificada como automática, simultânea e destrutiva. O método apresentado não requer o uso de tecnologias avançadas e de alto custo. Para aplicação deste método foi desenvolvido um protótipo que utiliza aquecimento do ar para derretimento da solda e força centrífuga para remoção dos componentes. O desenho deste equipamento permite a separação da PCI em 3 partes distintas: substrato, solda e componentes eletrônicos. Para a desmontagem no protótipo foram usadas placas marrons de fontes de alimentação, e placas verdes de memórias tipo RAM, com substrato de fenolite e de fibra de vidro respectivamente. A desmontagem foi realizada com sucesso em ambos os casos. Para as placas pesadas ou marrons, a faixa de operação que apresentou maior taxa de recuperação de solda (entre 2,2 e 2,8% do peso da PCI) e de componentes (entre 60 e 80% do peso da PCI) situa-se entre 200 e 206°C e 900 rpm. Para placas leves ou verdes, a desmontagem deve se situar entre 210 e 225°C e 900 rpm, sendo a quantidade de solda recuperada inferior a 1% e a de componentes aproximadamente 32% do peso da PCI. A liga de solda recuperada dos dois tipos de placas possui contaminação abaixo de 3%, teor semelhante à da borra proveniente de processos industriais de soldagem e que é utilizada como matéria prima.
In this work, is presented a new method for disassembly of obsolete or defective printed circuit board, from waste of electrical and electronic equipmente, for use in recycling. Disassembly objetives separate PCB to achives purer recycled material as well facilited the subsequent step in recycling process. Proposed disassembly is classified as automatic, simultaneous and destructive. The presented method doesn\'t required the use of advanced and expensives technologies. For this method, a prototype was developed. It utilizes centrifugal force and air heating for solder melting and components removal. Design of the prototype allows separation of PCB in 3 parts: substrate, solder and electronics components. Very low grades boards of paper laminated phenolic resins, from power supply of computers was used, as well as very high grade boards from RAM memory, made of fiberglass. Disassembly was sucessfully for both cases. For very low grade boards, operation range which has a greater amount of recovered solder (between 2,2 and 2,8% of weight of PCB) and components (between 60 and 80% of weight of PCB) is inside the range of temperature of 200 and 206°C and 900 rpm. For very high grade boards, disassembly is inside the range of temperature of 210 and 225°C and 900 rpm, with quantity of recovered solder under 1% and components aproximatelly 32% of weight of the PCB. Recovery solder for the two kinds of PCB has a contamination under 3%, similar to spare from industrial welding process, used as input in the production of new solders.
In this work, is presented a new method for disassembly of obsolete or defective printed circuit board, from waste of electrical and electronic equipmente, for use in recycling. Disassembly objetives separate PCB to achives purer recycled material as well facilited the subsequent step in recycling process. Proposed disassembly is classified as automatic, simultaneous and destructive. The presented method doesn\'t required the use of advanced and expensives technologies. For this method, a prototype was developed. It utilizes centrifugal force and air heating for solder melting and components removal. Design of the prototype allows separation of PCB in 3 parts: substrate, solder and electronics components. Very low grades boards of paper laminated phenolic resins, from power supply of computers was used, as well as very high grade boards from RAM memory, made of fiberglass. Disassembly was sucessfully for both cases. For very low grade boards, operation range which has a greater amount of recovered solder (between 2,2 and 2,8% of weight of PCB) and components (between 60 and 80% of weight of PCB) is inside the range of temperature of 200 and 206°C and 900 rpm. For very high grade boards, disassembly is inside the range of temperature of 210 and 225°C and 900 rpm, with quantity of recovered solder under 1% and components aproximatelly 32% of weight of the PCB. Recovery solder for the two kinds of PCB has a contamination under 3%, similar to spare from industrial welding process, used as input in the production of new solders.
Palavras-chave
Desmontagem, Reciclagem, Resíduos eletroeletrônicos, Disassembly, Recycling, Waste electrical and electronic equipment