Method and device for thermal ultrasonic low temperature sintering of nano silver conductive ink

Abstract

The invention discloses a hot ultrasonic low-temperature sintering method of a nano silver conductive ink. The method comprises the following steps: coating a flexible substrate with the nano silver conductive ink to form required interconnection line; respectively wrapping the upper surface and lower surface of the substrate with polyimide films respectively, and then putting the substrate on a bottom plate to prevent the interconnection line from being polluted; preheating the bottom plate to 100-150 DEG C and forming a temperature sintering environment; applying 50-20MPa of pressure and ultrasound with the frequency of 10-50KHz to the line for hot ultrasonic sintering; and carrying out hot ultrasonic sintering for 3-10 minutes, taking out the line and finishing sintering. The nano silver conductive ink trajectory on the flexible substrate is sintered in a hot ultrasonic sintering manner; the sintering temperature is reduced to 120 DEG C; the sintering time is greatly shortened to below 5 minutes; according to the nano silver conductive line subjected to the hot ultrasonic sintering, the compactness of nano silver particle distribution is increased under the ultrasound action; and the electrical resistivity of the nano silver interconnection line is reduced to 4.25*10<-8> (ohm.m).

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a thermosonic low-temperature sintering interconnection technology of nano-silver conductive ink. Background technique [0002] The rapid development of the field of microelectronics technology has continuously promoted the revolution of information technology, which has brought earth-shaking changes to the economy and society. All kinds of new electronic products have emerged. In the process of technological development, light, thin, and small have always been the goals of product development. Traditional rigid substrate electronic products have gradually been unable to meet people's needs for mobile products, prompting people to produce electronic products on thin and flexible substrates. idea. [0003] At this stage, nano-silver flexible circuits whose substrate materials are flexible paper, plastic, etc. may be a breakthrough point for the development of flexible circuits in...

AI Technical Summary

Problems solved by technology

The self-sintering temperature of nano-silver paste is generally higher than 200°C, but the maximum temperature that these substrates can withstand is mostly lower than 150°C, so it is difficult to be directly applied to make conductive lines on flexible substrates such as paper and plastic.

The conductive principle of the circuit is realized through the physical contact of silver powder particles. To achieve low resistivity, the contact area of ​​nano-silver particles and the bonding of particles between nano-silver particles must be increased. The circuit formed by the above-mentioned sintering method is due to the distribution of nano-silver particles. The density is not high, and the mutual adhesion is not strong, it is difficult to form a circuit with low resistivity

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