On September 12, 1958, Jack Kilby, a newly employed engineer at Texas Instruments Inc. (TI) ( an American technology company ) created the first practical integrated circuit.
Main reason:
The quality of circuit board and components. Since the mainly hardware of the electronic equipment consists of circuit board and components , which decides to the lifespan of an electronic equipment directly.
In order to make the SMT welding more convenient, the circuit board need to place three fiducial mark in the triangular position of the top and bottom side.
Actually, there are at least two thermal shocks during the welding and assembly of electronic components, which affect the accuracy and stability of electronic components.
As we all know, the signal in a circuit board all correspond to the certain functions, which is also associated with the working state of the corresponding components.
Generally, a layer of copper foil is bonded to the substrate of the PCB. And there are usually four kinds of copper foil thickness, such as 18 μ m, 35 μ m, 55 μ m and 70 μ m;
However, some of them need up to be 3oz-10oz or even heavier. Thus these
You know, Mg-Al alloy is characterized by light weight, high temperature strength and wearing resistance, which is the very needed material to the aeroplane fabrication.
Thus Mg-Al alloy is used in aeroplanes.
Here is the common thickness of finished PCB for your reference:
Rigid PCB: 0.5mm and 5mm or so;
Flex PCB: 0.1-0.2mm around;
Ultrathin Rigid PCB: 0.3-0.5mm.
Generally, engineering technicians tend to use such welding tools (like the constant temperature wind guns, small tin furnaces) to remove components smoothly.