Abstract: Methods for manufacturing a display device are provided. The methods include providing a plurality of light-emitting units and a substrate. The methods also include transferring the light-emitting units to a transfer head. The methods further include attaching at least one of the plurality of light-emitting units on the transfer head to the substrate by a bonding process, wherein the transfer head and the substrate satisfy the following equation during the bonding process: 0 ? ? ? T ? ? 1 T ? ? 2 ? A ? ( T ) ? dT - ? T ? ? 1 T ? ? 3 ? E ? ( T ) ? dT ? ? < 0.01 wherein A(T) is the coefficient of thermal expansion of the transfer head, E(T) is the coefficient of thermal expansion of the substrate, T1 is room temperature, T2 is the temperature of the transfer head, and T3 is the temperature of the substrate.

Abstract: A welding method for steel reinforcements, wherein electric current flows through the reinforcements, an electroslag pool formed from a solder melted by an electric arc generates a lot of heat to melt the reinforcements, pressure is applied to combine the same; the method uses a clamping device, wherein a sliding chuck is adjustably rotated by means of a bolt handle thereon to enhance a movable clamping seat to clamp the upper reinforcement, then a fixed chuck is adjustably rotated by means of another bolt handle to enhance another movable clamping seat to clamp the lower reinforcement, a crank provided at one side of a main body can be optionally rotated forwardly or backwardly to raise or lower the upper reinforcement, or the upper and the lower reinforcements can be compressed for combining.