Matko Erceg

Kinetic analysis of the non-isothermal degradation of poly(vinyl chloride)/poly(ethylene oxide) blends

Kinetic analysis of the non-isothermal degradation of poly(vinyl chloride)/poly(ethylene oxide) (PVC/PEO) blends was performed using isoconversional Friedman method in combination with the multivariate nonlinear regression method. The dependencies of E on α have been evaluated at whole conversion range, and it was concluded that E depends on α for all investigated samples, which indicated the complex degradation mechanism. The kinetic analysis indicated four-stage degradation mechanism, except for PVC sample which showed five-stage degradation mechanism. As the PEO content increased in the investigated samples, the probable mechanism changed from the reaction of nth order with autocatalysis (Cn) to the Avrami–Erofeev reaction type (An).

Different approaches to the kinetic analysis of thermal degradation of poly(ethylene oxide)

Kinetic analysis of the non-isothermal degradation of poly(ethylene oxide) has been performed using isoconversional model-free methods, model-fitting methods, invariant kinetic parameters method and Netzsch Thermokinetics software in order to establish whether different kinetic approaches yield consistent kinetic parameters. It has been shown that these approaches yield consistent kinetic parameters and can be combined in such a way as to enhance the reliability and quality of each other and consequently the overall kinetic analysis. The most probable kinetic parameters for the non-isothermal degradation of poly(ethylene oxide) have been determined. These kinetic parameters have been used for prediction of isothermal kinetics of poly(ethylene oxide), and their potential for reliable prediction has been noticed.

The influence of poly(ethylene glycol) on thermal properties of poly(vinyl chloride)/poly(ethylene oxide) blends

The influence of poly(ethylene glycol) (PEG) on thermal characteristics and thermal degradation of poly(vinyl chloride)/poly(ethylene oxide) (PVC/PEO) blends was investigated by differential scanning calorimetry and dynamic thermogravimetry. The thermal degradation characteristics of PEO remain unchanged upon PEG addition, while for all other investigated blends their values decreased, particularly at higher PVC content. Kinetic analysis of the non-isothermal degradation of investigated PVC/PEO/PEG blends was performed using isoconversional Friedman method in combination with the multivariate nonlinear regression method. The PEG addition lowers the values of the activation energies of PVC/PEO blends. The kinetic analysis indicated four-stage degradation mechanism for all investigated blends.

Optimum Chip-Tape Adhesion for Reliable Pickup Process

An efficient UV-irradiation process plays an important role for a successful pickup of very thin (

Thermal degradation of poly(3-hydroxybutyrate) plasticized with acetyl tributyl citrate

< d = 100~\mu \text{m}

Dynamic thermogravimetric degradation of poly(3-hydroxybutyrate)/aliphatic-aromatic copolyester blends

) Si chips, such as for integrated circuits, power semiconductors, or microelectromechanical systems devices. Before the UV-irradiation process, a dicing tape is laminated on the back of the wafer to hold it tightly (high adhesion strength), which enables rapid and smooth dicing of the wafer into separate Si chips. In the second stage, the adhesive layer is irradiated with UV light through the front side of the backing substrate, which decreases the adhesion strength to the level where the diced chips are picked up easily for further die-bonding processes. However, various malfunctions during the UV-irradiation process can lead to a different and occasionally insufficient UV dose. Consequently, the adhesion is not sufficiently reduced, which could later lead to pickup problems at the die-attach equipment during assembly. In this paper, we present the consequences of an insufficient UV dose on adhesion behavior and pickup efficiency. Using calculated adhesive energy, pickup simulation was done, and accumulated stress in the chips was evaluated at different UV doses. At lower UV doses, the adhesive energy showed rate-dependent behavior, while at higher UV doses, such a behavior was not shown. The accumulated stress within chips showed a linear correlation to adhesive energy, where at lower UV doses, the strength of the silicon chip was exceeded. In the practical process, with an increased pickup rate, higher energy is needed to delaminate the chip. With higher energy needed, accumulated stress in the chip is increased and could lead to the breaking of the chip.