Abstract: The present invention provides a high-strength and high-heat-resistant bio-based polyamide composition, which consists of the following parts of materials by mass: 43.50-89.95% of bio-based polyamide resin slices; 10-50% of reinforcements; 0.01-2% of rare earth compounds; 0.01-1% of copper salt antioxidant combinations; 0.01-1% of free-radical scavengers; 0.01-0.5% of heat-conducting masterbatches; 0.01-1% of stabilizers; and 0-1% of dispersants. The advantage of the present invention is presented in that: the bio-based polyamide resin slice is prepared through a stepwise polycondensation process of pentanediamine and adipic acid, or through a stepwise polycondensation process of pentanediamine, adipic acid and terephthalic acid and the pentanediamine is prepared through fermentation of starch, so the prepared polyamide resin pertains to an environmentally-friendly engineering plastic.

Abstract: Disclosed are an LED chip structure and its manufacturing method, and a mass transfer method applying the LED chip structure. The LED chip structure includes a substrate, a light emitting unit connected to the substrate, a passivation layer, an ohmic contact layer, and a metal layer formed at the junction of the light emitting unit and the substrate. The passivation layer surrounds the periphery of the light emitting unit and is connected to the metal layer, and the ohmic contact layer is covered onto the passivation layer and connected to the light emitting unit. The LED chip structure has the features of reasonable design and convenient transfer; the manufacturing method has the features of simple manufacture process, easy manufacture, and compact LED chip structure; and the mass transfer method applying the LED chip structure has the features of simple operation, easy alignment, and convenient transfer.

Abstract: A semiconductor power device includes a substrate, a power chip, and a capping layer, and the substrate has a patterned unit, and the thickness of the substrate is matched with the configuration of the power chip, and the height of the power chip is smaller than the thickness of the substrate, and the power chip is installed at a position corresponding to the patterned unit, and the capping layer is covered onto a side of the patterned unit having the substrate, and the power chip is covered by the capping layer and installed to the substrate. This invention features a simple structure and reasonable design. Since the height of the patterned unit is matched with the thickness of the power chip, therefore the height of the installed power chip is lower than the substrate to facilitate the installation of the capping layer and the dissipation of heat.

Abstract: An apparatus and method for growing nitride bulk single crystal, including an autoclave having a pre-growth zone and a growth zone. With control of the concentration of a saturated solution in a pre-growth chamber, the oversaturation reaction conditions for the overall process of growth of the nitride bulk single crystal can be regulated. By regulating the liquid level difference of the melt on an upper surface of a seed crystal, nucleation growth of N/Ga is preferentially performed on the surface of the seed crystal, which suppresses polycrystal formation at a gas-liquid interface and improves the growth rate of crystal and the utilization rate of raw materials.

Abstract: The present application discloses a composite substrate with a protective layer for preventing metal from diffusing, comprising: a thermally and electrically conductive layer (2) having a melting point of greater than 1000° C., and a GaN mono-crystalline layer (1) located on the thermally and electrically conductive layer (2). At least the side wall of the composite substrate is cladded with a protective layer (3) for preventing metal from diffusing. The composite substrate not only takes account of the homoepitaxy required for GaN epitaxy and improves the quality of the crystals, but also can be used directly to prepare LEDs with vertical structures and significantly reduce costs. The disclosed composite substrate effectively avoids the pollution of experimental instruments by the diffusion and volatilization of a metal material during the growth of MOCVD at high temperature.

Abstract: An apparatus and method for growing nitride bulk single crystal, including an autoclave having a pre-growth zone and a growth zone. With control of the concentration of a saturated solution in a pre-growth chamber, the oversaturation reaction conditions for the overall process of growth of the nitride bulk single crystal can be regulated. By regulating the liquid level difference of the melt on an upper surface of a seed crystal, nucleation growth of N/Ga is preferentially performed on the surface of the seed crystal, which suppresses polycrystal formation at a gas-liquid interface and improves the growth rate of crystal and the utilization rate of raw materials.

Abstract: The present application discloses a composite substrate with a protective layer for preventing metal from diffusing, comprising: a thermally and electrically conductive layer (2) having a melting point of greater than 1000° C., and a GaN mono-crystalline layer (1) located on the thermally and electrically conductive layer (2). At least the side wall of the composite substrate is cladded with a protective layer (3) for preventing metal from diffusing. The composite substrate not only takes account of the homoepitaxy required for GaN epitaxy and improves the quality of the crystals, but also can be used directly to prepare LEDs with vertical structures and significantly reduce costs. The disclosed composite substrate effectively avoids the pollution of experimental instruments by the diffusion and volatilization of a metal material during the growth of MOCVD at high temperature.

Abstract: The present application discloses a composite substrate used for GaN growth, comprising a thermally and electrically conductive layer (1) with a melting point greater than 1000° C. and a mono-crystalline GaN layer 2 (2) located on the thermally and electrically conductive layer (1). The thermally and electrically conductive layer (1) and the mono-crystalline GaN layer 2 (2) are bonded through a van der Waals force or a flexible medium layer (3). The composite substrate can further include a reflective layer (4) located at an inner side, a bottom part, or a bottom surface of the mono-crystalline GaN layer 2. In the disclosed composite substrate, iso-epitaxy required by GaN epitaxy is provided; crystalline quality is improved; and a vertical structure LED can be directly prepared. Further, a thin mono-crystalline GaN layer 2 greatly reduces cost, which is advantageous in applications.

Abstract: A method for preparing a composite substrate for GaN growth includes: growing a GaN monocrystal epitaxial layer on a sapphire substrate, bonding the GaN epitaxial layer onto a temporary substrate, lifting off the sapphire substrate, bonding the GaN epitaxial layer on the temporary substrate with a thermally and electrically conducting substrate, shedding the temporary substrate, and obtaining the composite substrate in which the GaN layer having a surface of gallium polarity is bonded to the conducting substrate. If the GaN layer on the sapphire substrate is directly bonded to the conducting substrate, after the sapphire substrate is lifted off, a composite substrate in which a GaN epitaxial layer having a surface of nitrogen polarity is bonded to the conducting substrate. The disclosed composite substrates have homoepitaxy and improved crystal quality; they can be used for forming LED and other devices at greatly reduces costs.

Abstract: A solid-state laser lift-off apparatus comprises: a solid-state laser (1), a light beam shaping lens (3), motors of oscillating mirrors (5,7), oscillating mirrors (4,6), a field lens (9), a movable platform (10), an industrial control computer and control software (8). The light beam shaping lens (3) is behind the solid-state laser (1), shaping the laser beam from the solid-state laser (1) into required shape. The motors of oscillating mirrors (5,7) are in front of the field lens (9), controlling the movement of the oscillating mirrors (4,6) according to the instruction of the control software (8) to implement different light beam scanning paths. A lift-off method for applying the solid-state laser lift-off apparatus uses a small laser spot to perform scanning, and enables damage-free separation of GaN from a sapphire substrate.

Abstract: A method for nondestructive laser lift-off of GaN from sapphire substrates is disclosed. A solid-state laser is used as the laser source. A small laser-spot having a perimeter length of 3 to 1000 micrometers and a distance of two farthest corners or a longest diameter of no more than 400 micrometers is used for laser scanning point-by-point and line-by-line. The energy at the center of the laser-spot is the strongest and is gradually reduced toward the periphery. A nondestructive laser lift-off with a small laser-spot is achieved. The scanning mode of the laser lift-off is improved. Device lift-off can be achieved without the need of aiming. As a result, the laser lift-off process is simplified, and the efficiency is improved while the rejection rate is reduced. The obstacles of the industrialization of the laser lift-off process are removed.

Abstract: A solid-state laser lift-off apparatus comprises: a solid-state laser (1), a light beam shaping lens (3), motors of oscillating mirrors (5,7), oscillating mirrors (4,6), a field lens (9), a movable platform (10), an industrial control computer and control software (8). The light beam shaping lens (3) is behind the solid-state laser (1), shaping the laser beam from the solid-state laser (1) into required shape. The motors of oscillating mirrors (5,7) are in front of the field lens (9), controlling the movement of the oscillating mirrors (4,6) according to the instruction of the control software (8) to implement different light beam scanning paths. A lift-off method for applying the solid-state laser lift-off apparatus uses a small laser spot to perform scanning, and enables damage-free separation of GaN from a sapphire substrate.

Abstract: A method for nondestructive laser lift-off of GaN from sapphire substrates utilizing a solid-state laser is disclosed in the present invention, wherein, a solid-state laser is used as the laser source, and a small laser-spot with a circumference of 3 to 1000 micrometers and a distance of two farthest corners or a longest diameter of no more than 400 micrometers is used for laser scanning point-by-point and line-by-line, wherein the energy in the small laser-spot is distributed such that the energy in the center of the laser-spot is the strongest and is gradually reduced toward the periphery. According to the present invention, a nondestructive laser lift-off with a small laser-spot is achieved, and a scanning mode of the laser lift-off is improved, thereby a lift-off method without the need of aiming is achieved.