Inverted LED light source

Abstract

The invention discloses an inverted LED light source, which comprises a substrate and at least one LED chip, and is characterized in that the LED chip is combined with the front surface of the substrate through a first surface with an electrode, and a second surface of the LED chip is a light emitting surface and is opposite to the first surface; and at least one pair of P electrodes and N electrodes of at least one LED chip are in heat conduction connection with the front face of the substrate through a plurality of heat conductors arranged at intervals, and the maximum size a of any heat conductor in the direction parallel to the first surface is smaller than the minimum distance d between the P electrodes and the N electrodes. According to the flip-chip LED light source provided by theinvention, a flip-chip bonding technology and a self-alignment isolation technology are combined, so that the chip yield is improved, and the thermal expansion stress of a welding interface is reduced; and meanwhile, the requirement on the alignment precision of equipment is reduced, so that the production cost is reduced, and the yield is improved.

Description

technical field [0001] The invention relates to an LED light source, in particular to a flip-chip LED light source, and belongs to the technical field of semiconductors. Background technique [0002] In flip-chip LEDs, in order to ensure that there is no short circuit between the PN electrodes of the chip when the chip is bonded, it is necessary to have a certain distance between the PN electrodes. On the other hand, in order to reduce the junction temperature, the contact area between the chip and the substrate needs to be as large as possible. , the pitch of the PN electrodes should be as small as possible, and traditional flip-chip technology usually requires devices to have high alignment accuracy, which will increase production costs. [0003] For example, the existing flip-chip LED light source structure such as figure 1 As shown, however, due to the limitation of production technology, the processing accuracy of the metal layer spacing on the substrate is currently o...

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Problems solved by technology

[0003] For example, the existing flip-chip LED light source structure such as figure 1 As shown, however, due to the limitation of production technology, the processing accuracy of the metal layer spacing on the substrate is currently on the sub-micron level, and the spacing d1 of the PN electrodes on the existing chip is ≥ 150 μm; the schematic diagram of heat transfer is shown in figure 2 As shown, heat needs to be transported horizontally to the electrode area in the chip first, and then to the substrate vertically, which will increase the heat transport distance and thus increase the thermal resistance; in order to improve the heat dissipation capability and electrical conductivity of the chip, the metal layer of the substrate needs to have The size of the chip electrode matches, so the equipment needs to have high alignment accuracy during packaging. The alignment error of this structure is the distance between the PN electrodes, otherwise it will easily cause a short circuit; the chip will generate a lot of heat when it emits light, and the contact between the chip and the metal layer material Large area and different thermal expansion coefficients tend to generate thermal expansion stress on the contact surface, resulting in reduced device reliability

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