SMT pcb Automotive pcb assembly
|Material||Laminate material||FR4, Alu, CEM3,Taconic,Rogers|
|Board cutting||Number of layers||1-58|
Min.Thickness for inner layers
(Cu thickness are excluded)
|Bow and twist||<7/1000|
|Copper weight||outer Cu weight||0.5-4 oz|
|inner Cu weight||0.5-3 oz|
|PTH hole tolerance||±0.002''(0.005mm)|
|NPTH Hole tolerance||±0.002''(0.005mm)|
|Plating||Min hole size||0.0008''（0.02mm）|
|Aspect ratio||20(5 :1)|
|Min solder mask clearance||0.003''(0.07mm)|
|E-test||Flying probe tester||Y|
|Impedance tester||Tektronix TDS8200|
|Surface finish||HASL,ENIG,immersion silver，immersion tin, OSP....|
SMT patch refers to the abbreviation of the series of processes processed on the basis of PCB, and the PCB is a printed circuit board. SMT is a surface assembly technology and is the most popular technology and process in the electronics assembly industry.
The selection and design of SMT Automotive Pcb Assembly is a key part of the overall design of the product. The designer determines the electrical performance and function of the components in the system structure and detailed circuit design stage. In the SMT design phase, it should be based on the specific conditions and overall conditions of the equipment and process. The design requirements determine the package form and structure of the surface mount components. Surface mount solder joints are both mechanical joints and electrical joints. Reasonable choices have a decisive influence on improving PCB design density, manufacturability, testability and reliability.
The surface mount components are functionally different from the plug-in components, and the difference is in the package of the components. Surface-mounted packages must withstand high temperature-resistant components and substrates that must have a matching coefficient of thermal expansion during soldering. These factors must be considered in the product design.
Choosing the right package has the following advantages:
1) Effectively save PCB area;
2) Provide better electrical performance;
3) Protect the internal parts of the components from environmental influences such as moisture;
4) Provide good communication links;
5) Help heat dissipation and facilitate transmission and testing.