Clayens NP Group
Expanding application possibility of In-Mold Electronics*1 for automobilesIn development of high-performance IME, which contributes to improvement of weight saving and design flexibility of car, there is a problem...
*1 In-Mold Electronics (IME) is the technology in which the functional printed electronics films are molded into 3D shape by thermoforming and injection.
IME is attracting attention in order to replace of traditional structure parts using metal wire harness installed in automobiles and airplanes because it is expected to contribute to weight saving and design flexibility, number of parts, reduction of the lead time of experimental productions compared with conventional way of using rigid circuit board and metal wire harness. The polymer and precise metal component manufacturer Clayens NP in France is also working on the development of the IME.
Types of ECU*2 are limited due to higher electrical resistance of IME
IME aims to create electric circuits on flexible boards before sealing it with resin by overmolding. Conductive pastes of this electric circuits are simply printed thinly without sintering processing, so its electrical resistance is higher than conventional rigid circuit board using thicker copper (high conductivity). Thus, large current cannot be flowed and only a device of low power consumption such as LED illumination, haptics touch sensor*3 can be operated. ECU equipped with drive IC with large power consumption can’t be operated.
*2 ECU=Electronic Control Unit. 50 to 100 units are placed in a car.
*3 The touch has a physical reaction when touched. Gives a smarter operability compared with the general switch.
Energy storage devices which is applicable in IME isn’t found...
To compensate this lower conductivity, it was considered to use so-called dispersed power source, which is an energy storage device is installed near ECU, instead of supplying power to each ECU from a car battery via IME for a long distance.
For doing this, it’s necessary to mold an energy storage device into IME. But there was no energy storage device which can endured high temperature and high pressure applied during injection molding. Besides, long lifetime is also necessary because it’s difficult to exchange an energy storage device after overmolding.
ECU which can be driven by IME is limited because of its high electrical resistance.
An energy storage device which can endure the high temperatures and pressures applied during the overmolding process is necessary for dispersed power source IME.
A long lifetime is also mandatory because it becomes almost impossible to replace energy storage device after molding.