An electronic component sub-mount includes a body having a top surface, a bottom surface, and a supporting surface. The top and bottom surfaces are located on opposite sides of the body. The supporting surface is located on one side of the body, and an angle that is not equal to 0 degrees is formed between the supporting surface and the bottom surface. A first conductive layer is disposed on the bottom surface and includes multiple first conductive lines. A second conductive layer is disposed on the supporting surface, extending to the top surface, and includes multiple second conductive lines. The second conductive lines on the supporting surface have a first pin layout, and the second conductive lines on the top surface have a second pin layout different from the first pin layout. The second pin layout matches the pin layout of first conductive lines on the bottom surface.

An aircraft LED light unit comprises at least one printed circuit board which comprises at least one metal core layer and at least one dielectric layer, and at least one LED disposed on the printed circuit board and which comprises an anode and a cathode for electrically coupling to a power source. One of the anode and cathode of the at least one LED is connected to an electrical conductor which is disposed on the dielectric layer and is coupled to a first terminal of the power source, wherein the dielectric layer electrically isolates the electrical conductor from the metal core layer, and the other one of the anode and cathode of the at least one LED is connected to the metal core layer of the at least one printed circuit board, wherein the metal core layer is coupled to a second terminal of the power source.

A mounting substrate includes a through-hole 13 formed in a substrate 10, a first land part 21, a second land part 31, a first component attaching part 22, a second component attaching part 32, a conductive layer 14, and a filling member 15 filled into a part of the through-hole 13. A shortest distance allowable value L.sub.0 from the center of the first land part 21 to a component 51 is determined on the basis of the volume V.sub.h of a part of the through-hole 15 positioned above a top surface of the filling member 15 on the side of the first land part 21, the length L.sub.1 of the component 51 to be mounted to the first component attaching part 22, and the maximum allowable value of the inclination of the component 51 to be mounted to the first component attaching part 22 relative to the first surface 11 of the substrate 10.

An electronic device includes an electronic component module coupled to a substrate. The electronic component module includes a sub-mount, which includes a body having a top surface, a bottom surface, and a supporting surface. The supporting surface is located between the supporting surface and the bottom surface. A first conductive layer is disposed on the bottom surface and includes first conductive lines. A second conductive layer is disposed on the supporting surface, extending to the top surface, and includes second conductive lines. The second conductive lines on the supporting surface have a first pin layout, and the second conductive lines on the top surface have a second pin layout different from the first pin layout. The second pin layout matches the pin layout of first conductive lines on the bottom surface. An electronic component is coupled to the second conductive lines on the supporting surface.