In the related art, as a method for mounting an electronic component on a substrate, a method (a reflow method) in which an electronic component is temporarily fixed to a predetermined position of a substrate to which solder is attached in advance, the substrate is then heated by means of infrared light, hot air, or the like to melt the solder, and an electronic component is fixed has been adopted. It is possible to increase the mounting density of the electronic component on the surface of the substrate by the method.
However, the electronic component which has been used in the related art has insufficient heat resistance and particularly, in a reflow process using infrared heating, a problem that the surface temperature of the component increases locally, or the like arises. Thus, there has been a demand for a resin composition and an electronic component having further excellent heat resistance.
In addition, since an LED element as a semiconductor light emitting device has a small size, a long life, and excellent power saving performance, LED elements have been widely used as a light source of a display lamp, or the like. In recent years, an LED element having higher brightness has been produced at a relatively low cost, and thus, the use of LED elements as a light source in place of a fluorescent lamp and a light bulb has been considered. When LED elements are used as such a light source, a method has been frequently used in which plural LED elements are arranged on a surface mounting type LED package, that is, a metal substrate (LED mounting substrate) of aluminum or the like, and a reflector (a reflecting body) which reflects light in a predetermined direction is arranged in the vicinity of each LED element to obtain high illuminance.
However, since LED elements give off heat generation during light emitting, in an LED light device adopting such a method, the reflector is deteriorated due to a rising temperature during light emitting of the LED elements, and the reflectivity is degraded and brightness is degraded. Thus, the lifetime of the LED element is shortened. Accordingly, heat resistance is required for the reflector.
In order to respond to the requirement of the heat resistance, in PTL 1, a polymer composition which is used in a reflector of a light emitting diode is proposed and specifically, a polymer composition including polyphthalamide, carbon black, titanium dioxide, glass fibers, and an antioxidant is disclosed. The reflectivity of the composition is measured after the composition undergoes heat aging. The composition has satisfactory reflectivity with less yellowing compared to a polymer composition not including carbon black.
In addition, in PTL 2, a thermosetting light reflecting resin composition using an optical semiconductor device in which an optical semiconductor element and wavelength converting means such as a fluorescent substance are combined is disclosed.