Investigation of the Thermal Properties of Electrodes on the Film and Its Heating Behavior Induced by Microwave Irradiation in Mounting Processes

Kenji Kanazawa,Sei Uemura,Takashi Nakamura,Masateru Nishioka

doi:10.3390/pr8050557

Kenji Kanazawa, Sei Uemura + Show 2 more

Open Access

https://doi.org/10.3390/pr8050557

Copy DOI

Abstract

We have developed a novel microwave (MW) soldering system using a cylindrical single-mode TM110 MW cavity that spatially separates the electric fields at the top and bottom of the cavity and the magnetic field at the center of the cavity. This MW reactor system automatically detects the suitable resonance frequency and provides the optimum MW irradiation conditions in the cylindrical cavity via a power feedback loop. Furthermore, we investigated the temperature properties of electrodes by MW heating with the simulation of a magnetic field in the TM110 cavity toward the mounting of electronic components by MW heating. We also developed a short-time melting technology for solder paste on polyimide substrate using MW heating and succeeded in mounting a temperature sensor using the novel MW heating system without damaging the electronic components, electronic circuits, and the substrate.

Highlights

The Internet of Things (IoT) applications include smart grids, smart homes [1], sensors [2,3], and actuators [4]
The heating process used in conventional industrial solder mounting requires temperatures of more than 170 ◦ C for about 300 s [7,8], which means that the glass transition temperature (Tg ) of flexible substrates such as polyethylene terephthalate (PET, Tg = 120 ◦ C) and polyethylene naphthalate (PEN, Tg = 140 ◦ C) should be higher than this if conventional industrial solder mounting systems are to be used
We found that the sample could be heated by the magnetic field of MW

Summary

Introduction

The Internet of Things (IoT) applications include smart grids, smart homes [1], sensors [2,3], and actuators [4] Their applications are remotely accessible and enable the exchange of information, allowing for the control of electrical devices and monitoring healthcare from anywhere on the network. In smart sensors and actuators, technological developments in mounting electronic components on a flexible substrate (such as textile, plastic substrates, and stretchable thermoplastic elastomer resins) are urgently required [2,3]. It is impossible to mount components on flexible and/or stretchable substrates that have low thermostability using solder as a connection material

Methods

Results

Conclusion