Polytronics Technology Corporation

Jyh Ming Yu

David Shau Chew Wang

Shau Chew Wang

Fu Hua Chu

Kuo Chang Lo

Kuo Hsun Chen

En Tien Yang

A light emitting diode (LED) apparatus with temperature control and current regulation functions is provided. The LED apparatus includes at least one LED die and at least one temperature control and current regulation (TCCR) device. The TCCR device is electrically connected between the LED die and a power source, and is placed within an effective temperature sensing distance of the LED die, so as to sense temperature changes of the LED die. The resistance of the TCCR device is proportional to the temperature in a range of 25&#xb0; C. to 85&#xb0; C., i.e., the resistance increases with temperature. Moreover, the resistance difference of the TCCR device between 50&#xb0; C. and 80&#xb0; C. is greater than or equal to 100 m&#x3a9;.

Light emitting diode apparatus

A heat-conductive dielectric polymer material having an inter-penetrating-network (IPN) structure includes a polymer component, a curing agent, and a heat-conductive filler uniformly dispersed in the polymer component. The polymer component includes a thermoplastic plastic and a thermosetting epoxy resin. The curing agent is used to cure the thermosetting epoxy resin at a curing temperature. The heat conductivity of the heat-conductive dielectric polymer material is larger than 0.5 W/mK. A heat dissipation substrate including the heat-conductive dielectric polymer material in the present invention has a thickness of less than 0.5 mm and bears a voltage of over 1000 volts.

Heat-conductive dielectric polymer material and heat dissipation substrate containing the same

A method for manufacturing an over-current protection device comprises a step of providing at least one current sensitive device and a step of pressing. The current sensitive device comprises a first electrode foil, a second electrode foil and a PTC conductive layer physically laminated between the first and second electrode foils. The pressing step is to press the current sensitive device at a predetermined temperature, thereby generating at least one overflow portion at sides of the PTC conductive layer to form the over-current protection device. The predetermined temperature is higher than the softening temperature of the PTC conductive layer. The over-current protection devices manufactured according to the present invention have superior resistance distribution.

Method for manufacturing over-current protection device

An LED apparatus with temperature self-regulating, over-temperature protection, and over-current protection function comprises an LED chip, a heat dissipation plate, a heat conductive layer and a temperature control device. The heat dissipation and the heat conductive layer disposed thereon carry the LED chip and dissipate the heat generated from the LED chip that is connected to an electric power source for luminance. The temperature control device exhibiting PTC behavior is electrically connected between the LED chip and the electric power source in series, and the distance between the LED chip and the temperature control device is less than 3 cm. The heat conductive layer can consist of polymeric dielectric material and has a heat conduction coefficient larger than 1.0 W/mK at 25&#xb0; C.

LED apparatus with temperature control function

A high voltage over-current protection device includes a positive temperature coefficient (PTC) electrically conductive heat-dissipation layer and two metal electrodes. The PTC electrically conductive heat-dissipation layer includes at least one polymer, an electrically conductive filler, and a heat conductive filler. Due to the high thermal conductivity of the heat conductive filler (with a coefficient of thermal conductivity higher than 1 W/mK), the high voltage over-current protection device has a high thermal conduction characteristic, and the withstand voltage thereof can be substantially uniformly distributed in the PTC electrically conductive heat-dissipation layer to enhance its high voltage withstanding characteristic.

High voltage over-current protection device

An over-current protection device comprises two metal foils and a PTC material layer laminated between the two metal foils. The PTC material layer essentially comprises a polymer matrix and a conductive filler. The polymer matrix at least comprises a first crystalline polymer, e.g., LDPE, and a second crystalline polymer, e.g., PVDF, in which the melting temperature of the second crystalline polymer subtracting the melting temperature of the first crystalline polymer is equal to or more than 50&#xb0; C. The conductive filler is selected from metallic grain of a volumetric resistivity less than 500 &#x3bc;&#x3a9;-cm, and is distributed in the polymer matrix. The initial volumetric resistivity of the PTC material layer is less than 0.1&#x3a9;-cm, and the trip temperature of the PTC material layer at which the resistance thereof increases to 1000 times the initial resistance subtracting the melting temperature of the first crystalline polymer is less than 15&#xb0; C.

Over-current protection device

An over-current protection device comprises two metal foils and a positive temperature coefficient (PTC) material layer laminated between the two metal foils. The PTC material layer includes: (1) a polymer substrate, being 35-60% by volume of the PTC material layer and including a fluorine-containing crystalline polymer with a melting point higher than 150&#xb0; C., e.g., polyvinylidine fluoride (PVDF); and (2) a conductive ceramic filler (e.g., titanium carbide) distributed in the polymer substrate. The conductive ceramic filler is 40-65% by volume of the PTC material layer, and has a volume resistivity less than 500 &#x3bc;&#x3a9;-cm. The volume resistivity of the PTC material layer is less than 0.1 &#x3a9;-cm, and the ratio of the hold current of the PTC material layer at 25&#xb0; C. to the area of the PTC material layer is between 0.05 and 0.2 A/mm.

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Kaohsiung, Taiwan

Jyh Ming Yu