Banca de QUALIFICAÇÃO: LUCAS LOPES MENDES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCAS LOPES MENDES
DATE: 21/12/2023
TIME: 14:00
LOCAL: Online
TITLE:

PHYSICAL AND CHEMICAL ANALYSIS OF SILICONE COATINGS FOR THE PROTECTION OF LED MODULAR BOARDS

KEY WORDS:

Conformal coating, UV curing, LED, Silicone

PAGES: 70
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Tecnologia Química
SPECIALTY: Polímeros
SUMMARY:

Currently, most devices used in everyday life contain printed circuit boards, known as PCBs. Essentially, this type of board consists of planar electrical circuits that have conductor traces and copper pads for the placement of electrical components. Modular boards formed by light-emitting diodes (LEDs) when used in information signaling systems for transportation and urban mobility are referred to as electronic panels. The assembly of boards for this device involves a series of processes, from component placement using technologies such as Surface Mount Device (SMD) to the final assembly, including procedures for protecting electrical components, such as conformal coating. This process involves the application of resin to protect electrical components against aggressive environmental factors, including weathering, mechanical stress, electrical discharges, among others, such as thermal stress and corrosion.

This work aims to chemically and physically characterize, as well as analyze hydrophobicity and adhesion characteristics, firstly for a thermally curable coating model, where the process is accelerated via a convection electric oven, and subsequently perform the same procedures for another coating curable by ultraviolet (UV) light. Both coatings are resins that use silicone as a base. Analytical techniques such as Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle analysis, and adhesion tests were applied.

FTIR revealed specific vibrational patterns associated with silicone structures, while TGA provided information on thermal decomposition, purity, and stability of the coating. Contact angle analysis showed the hydrophobic nature of both coatings, crucial for environments where moisture can compromise electronic components. Advantages in UV curing in terms of efficiency and performance were identified when compared to traditional thermal curing. Additionally, adhesion tests indicate that UV-cured coatings perform better in resisting mechanical peel forces.

Future tests are anticipated, including salt spray chamber tests, accelerated aging by UV light exposure, and chemical resistance evaluations. These results could provide crucial information for the selection of efficient conformal coatings on PCBs, contributing to the reliability of durable electronic products.

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